1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Atmel ADC driver for SAMA5D2 devices and compatible.
4 *
5 * Copyright (C) 2015 Atmel,
6 *               2015 Ludovic Desroches <ludovic.desroches@atmel.com>
7 *		 2021 Microchip Technology, Inc. and its subsidiaries
8 *		 2021 Eugen Hristev <eugen.hristev@microchip.com>
9 */
10
11#include <linux/bitops.h>
12#include <linux/clk.h>
13#include <linux/delay.h>
14#include <linux/dma-mapping.h>
15#include <linux/dmaengine.h>
16#include <linux/interrupt.h>
17#include <linux/io.h>
18#include <linux/module.h>
19#include <linux/mod_devicetable.h>
20#include <linux/platform_device.h>
21#include <linux/property.h>
22#include <linux/sched.h>
23#include <linux/units.h>
24#include <linux/wait.h>
25#include <linux/iio/iio.h>
26#include <linux/iio/sysfs.h>
27#include <linux/iio/buffer.h>
28#include <linux/iio/trigger.h>
29#include <linux/iio/trigger_consumer.h>
30#include <linux/iio/triggered_buffer.h>
31#include <linux/nvmem-consumer.h>
32#include <linux/pinctrl/consumer.h>
33#include <linux/pm_runtime.h>
34#include <linux/regulator/consumer.h>
35
36#include <dt-bindings/iio/adc/at91-sama5d2_adc.h>
37
38struct at91_adc_reg_layout {
39/* Control Register */
40	u16				CR;
41/* Software Reset */
42#define	AT91_SAMA5D2_CR_SWRST		BIT(0)
43/* Start Conversion */
44#define	AT91_SAMA5D2_CR_START		BIT(1)
45/* Touchscreen Calibration */
46#define	AT91_SAMA5D2_CR_TSCALIB		BIT(2)
47/* Comparison Restart */
48#define	AT91_SAMA5D2_CR_CMPRST		BIT(4)
49
50/* Mode Register */
51	u16				MR;
52/* Trigger Selection */
53#define	AT91_SAMA5D2_MR_TRGSEL(v)	((v) << 1)
54/* ADTRG */
55#define	AT91_SAMA5D2_MR_TRGSEL_TRIG0	0
56/* TIOA0 */
57#define	AT91_SAMA5D2_MR_TRGSEL_TRIG1	1
58/* TIOA1 */
59#define	AT91_SAMA5D2_MR_TRGSEL_TRIG2	2
60/* TIOA2 */
61#define	AT91_SAMA5D2_MR_TRGSEL_TRIG3	3
62/* PWM event line 0 */
63#define	AT91_SAMA5D2_MR_TRGSEL_TRIG4	4
64/* PWM event line 1 */
65#define	AT91_SAMA5D2_MR_TRGSEL_TRIG5	5
66/* TIOA3 */
67#define	AT91_SAMA5D2_MR_TRGSEL_TRIG6	6
68/* RTCOUT0 */
69#define	AT91_SAMA5D2_MR_TRGSEL_TRIG7	7
70/* Sleep Mode */
71#define	AT91_SAMA5D2_MR_SLEEP		BIT(5)
72/* Fast Wake Up */
73#define	AT91_SAMA5D2_MR_FWUP		BIT(6)
74/* Prescaler Rate Selection */
75#define	AT91_SAMA5D2_MR_PRESCAL(v)	((v) << AT91_SAMA5D2_MR_PRESCAL_OFFSET)
76#define	AT91_SAMA5D2_MR_PRESCAL_OFFSET	8
77#define	AT91_SAMA5D2_MR_PRESCAL_MAX	0xff
78#define AT91_SAMA5D2_MR_PRESCAL_MASK	GENMASK(15, 8)
79/* Startup Time */
80#define	AT91_SAMA5D2_MR_STARTUP(v)	((v) << 16)
81#define AT91_SAMA5D2_MR_STARTUP_MASK	GENMASK(19, 16)
82/* Minimum startup time for temperature sensor */
83#define AT91_SAMA5D2_MR_STARTUP_TS_MIN	(50)
84/* Analog Change */
85#define	AT91_SAMA5D2_MR_ANACH		BIT(23)
86/* Tracking Time */
87#define	AT91_SAMA5D2_MR_TRACKTIM(v)	((v) << 24)
88#define	AT91_SAMA5D2_MR_TRACKTIM_TS	6
89#define	AT91_SAMA5D2_MR_TRACKTIM_MAX	0xf
90/* Transfer Time */
91#define	AT91_SAMA5D2_MR_TRANSFER(v)	((v) << 28)
92#define	AT91_SAMA5D2_MR_TRANSFER_MAX	0x3
93/* Use Sequence Enable */
94#define	AT91_SAMA5D2_MR_USEQ		BIT(31)
95
96/* Channel Sequence Register 1 */
97	u16				SEQR1;
98/* Channel Sequence Register 2 */
99	u16				SEQR2;
100/* Channel Enable Register */
101	u16				CHER;
102/* Channel Disable Register */
103	u16				CHDR;
104/* Channel Status Register */
105	u16				CHSR;
106/* Last Converted Data Register */
107	u16				LCDR;
108/* Interrupt Enable Register */
109	u16				IER;
110/* Interrupt Enable Register - TS X measurement ready */
111#define AT91_SAMA5D2_IER_XRDY   BIT(20)
112/* Interrupt Enable Register - TS Y measurement ready */
113#define AT91_SAMA5D2_IER_YRDY   BIT(21)
114/* Interrupt Enable Register - TS pressure measurement ready */
115#define AT91_SAMA5D2_IER_PRDY   BIT(22)
116/* Interrupt Enable Register - Data ready */
117#define AT91_SAMA5D2_IER_DRDY   BIT(24)
118/* Interrupt Enable Register - general overrun error */
119#define AT91_SAMA5D2_IER_GOVRE BIT(25)
120/* Interrupt Enable Register - Pen detect */
121#define AT91_SAMA5D2_IER_PEN    BIT(29)
122/* Interrupt Enable Register - No pen detect */
123#define AT91_SAMA5D2_IER_NOPEN  BIT(30)
124
125/* Interrupt Disable Register */
126	u16				IDR;
127/* Interrupt Mask Register */
128	u16				IMR;
129/* Interrupt Status Register */
130	u16				ISR;
131/* End of Conversion Interrupt Enable Register */
132	u16				EOC_IER;
133/* End of Conversion Interrupt Disable Register */
134	u16				EOC_IDR;
135/* End of Conversion Interrupt Mask Register */
136	u16				EOC_IMR;
137/* End of Conversion Interrupt Status Register */
138	u16				EOC_ISR;
139/* Interrupt Status Register - Pen touching sense status */
140#define AT91_SAMA5D2_ISR_PENS   BIT(31)
141/* Last Channel Trigger Mode Register */
142	u16				LCTMR;
143/* Last Channel Compare Window Register */
144	u16				LCCWR;
145/* Overrun Status Register */
146	u16				OVER;
147/* Extended Mode Register */
148	u16				EMR;
149/* Extended Mode Register - Oversampling rate */
150#define AT91_SAMA5D2_EMR_OSR(V, M)		(((V) << 16) & (M))
151#define AT91_SAMA5D2_EMR_OSR_1SAMPLES		0
152#define AT91_SAMA5D2_EMR_OSR_4SAMPLES		1
153#define AT91_SAMA5D2_EMR_OSR_16SAMPLES		2
154#define AT91_SAMA5D2_EMR_OSR_64SAMPLES		3
155#define AT91_SAMA5D2_EMR_OSR_256SAMPLES		4
156
157/* Extended Mode Register - TRACKX */
158#define AT91_SAMA5D2_TRACKX_MASK		GENMASK(23, 22)
159#define AT91_SAMA5D2_TRACKX(x)			(((x) << 22) & \
160						 AT91_SAMA5D2_TRACKX_MASK)
161/* TRACKX for temperature sensor. */
162#define AT91_SAMA5D2_TRACKX_TS			(1)
163
164/* Extended Mode Register - Averaging on single trigger event */
165#define AT91_SAMA5D2_EMR_ASTE(V)		((V) << 20)
166
167/* Compare Window Register */
168	u16				CWR;
169/* Channel Gain Register */
170	u16				CGR;
171/* Channel Offset Register */
172	u16				COR;
173/* Channel Offset Register differential offset - constant, not a register */
174	u16				COR_diff_offset;
175/* Analog Control Register */
176	u16				ACR;
177/* Analog Control Register - Pen detect sensitivity mask */
178#define AT91_SAMA5D2_ACR_PENDETSENS_MASK        GENMASK(1, 0)
179/* Analog Control Register - Source last channel */
180#define AT91_SAMA5D2_ACR_SRCLCH		BIT(16)
181
182/* Touchscreen Mode Register */
183	u16				TSMR;
184/* Touchscreen Mode Register - No touch mode */
185#define AT91_SAMA5D2_TSMR_TSMODE_NONE           0
186/* Touchscreen Mode Register - 4 wire screen, no pressure measurement */
187#define AT91_SAMA5D2_TSMR_TSMODE_4WIRE_NO_PRESS 1
188/* Touchscreen Mode Register - 4 wire screen, pressure measurement */
189#define AT91_SAMA5D2_TSMR_TSMODE_4WIRE_PRESS    2
190/* Touchscreen Mode Register - 5 wire screen */
191#define AT91_SAMA5D2_TSMR_TSMODE_5WIRE          3
192/* Touchscreen Mode Register - Average samples mask */
193#define AT91_SAMA5D2_TSMR_TSAV_MASK             GENMASK(5, 4)
194/* Touchscreen Mode Register - Average samples */
195#define AT91_SAMA5D2_TSMR_TSAV(x)               ((x) << 4)
196/* Touchscreen Mode Register - Touch/trigger frequency ratio mask */
197#define AT91_SAMA5D2_TSMR_TSFREQ_MASK           GENMASK(11, 8)
198/* Touchscreen Mode Register - Touch/trigger frequency ratio */
199#define AT91_SAMA5D2_TSMR_TSFREQ(x)             ((x) << 8)
200/* Touchscreen Mode Register - Pen Debounce Time mask */
201#define AT91_SAMA5D2_TSMR_PENDBC_MASK           GENMASK(31, 28)
202/* Touchscreen Mode Register - Pen Debounce Time */
203#define AT91_SAMA5D2_TSMR_PENDBC(x)            ((x) << 28)
204/* Touchscreen Mode Register - No DMA for touch measurements */
205#define AT91_SAMA5D2_TSMR_NOTSDMA               BIT(22)
206/* Touchscreen Mode Register - Disable pen detection */
207#define AT91_SAMA5D2_TSMR_PENDET_DIS            (0 << 24)
208/* Touchscreen Mode Register - Enable pen detection */
209#define AT91_SAMA5D2_TSMR_PENDET_ENA            BIT(24)
210
211/* Touchscreen X Position Register */
212	u16				XPOSR;
213/* Touchscreen Y Position Register */
214	u16				YPOSR;
215/* Touchscreen Pressure Register */
216	u16				PRESSR;
217/* Trigger Register */
218	u16				TRGR;
219/* Mask for TRGMOD field of TRGR register */
220#define AT91_SAMA5D2_TRGR_TRGMOD_MASK GENMASK(2, 0)
221/* No trigger, only software trigger can start conversions */
222#define AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER 0
223/* Trigger Mode external trigger rising edge */
224#define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE 1
225/* Trigger Mode external trigger falling edge */
226#define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL 2
227/* Trigger Mode external trigger any edge */
228#define AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY 3
229/* Trigger Mode internal periodic */
230#define AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC 5
231/* Trigger Mode - trigger period mask */
232#define AT91_SAMA5D2_TRGR_TRGPER_MASK           GENMASK(31, 16)
233/* Trigger Mode - trigger period */
234#define AT91_SAMA5D2_TRGR_TRGPER(x)             ((x) << 16)
235
236/* Correction Select Register */
237	u16				COSR;
238/* Correction Value Register */
239	u16				CVR;
240/* Channel Error Correction Register */
241	u16				CECR;
242/* Write Protection Mode Register */
243	u16				WPMR;
244/* Write Protection Status Register */
245	u16				WPSR;
246/* Version Register */
247	u16				VERSION;
248/* Temperature Sensor Mode Register */
249	u16				TEMPMR;
250/* Temperature Sensor Mode - Temperature sensor on */
251#define AT91_SAMA5D2_TEMPMR_TEMPON	BIT(0)
252};
253
254static const struct at91_adc_reg_layout sama5d2_layout = {
255	.CR =			0x00,
256	.MR =			0x04,
257	.SEQR1 =		0x08,
258	.SEQR2 =		0x0c,
259	.CHER =			0x10,
260	.CHDR =			0x14,
261	.CHSR =			0x18,
262	.LCDR =			0x20,
263	.IER =			0x24,
264	.IDR =			0x28,
265	.IMR =			0x2c,
266	.ISR =			0x30,
267	.LCTMR =		0x34,
268	.LCCWR =		0x38,
269	.OVER =			0x3c,
270	.EMR =			0x40,
271	.CWR =			0x44,
272	.CGR =			0x48,
273	.COR =			0x4c,
274	.COR_diff_offset =	16,
275	.ACR =			0x94,
276	.TSMR =			0xb0,
277	.XPOSR =		0xb4,
278	.YPOSR =		0xb8,
279	.PRESSR =		0xbc,
280	.TRGR =			0xc0,
281	.COSR =			0xd0,
282	.CVR =			0xd4,
283	.CECR =			0xd8,
284	.WPMR =			0xe4,
285	.WPSR =			0xe8,
286	.VERSION =		0xfc,
287};
288
289static const struct at91_adc_reg_layout sama7g5_layout = {
290	.CR =			0x00,
291	.MR =			0x04,
292	.SEQR1 =		0x08,
293	.SEQR2 =		0x0c,
294	.CHER =			0x10,
295	.CHDR =			0x14,
296	.CHSR =			0x18,
297	.LCDR =			0x20,
298	.IER =			0x24,
299	.IDR =			0x28,
300	.IMR =			0x2c,
301	.ISR =			0x30,
302	.EOC_IER =		0x34,
303	.EOC_IDR =		0x38,
304	.EOC_IMR =		0x3c,
305	.EOC_ISR =		0x40,
306	.TEMPMR =		0x44,
307	.OVER =			0x4c,
308	.EMR =			0x50,
309	.CWR =			0x54,
310	.COR =			0x5c,
311	.COR_diff_offset =	0,
312	.ACR =			0xe0,
313	.TRGR =			0x100,
314	.COSR =			0x104,
315	.CVR =			0x108,
316	.CECR =			0x10c,
317	.WPMR =			0x118,
318	.WPSR =			0x11c,
319	.VERSION =		0x130,
320};
321
322#define AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US          2000    /* 2ms */
323#define AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US    200
324
325#define AT91_SAMA5D2_XYZ_MASK		GENMASK(11, 0)
326
327#define AT91_SAMA5D2_MAX_POS_BITS			12
328
329#define AT91_HWFIFO_MAX_SIZE_STR	"128"
330#define AT91_HWFIFO_MAX_SIZE		128
331
332#define AT91_SAMA5D2_CHAN_SINGLE(index, num, addr)			\
333	{								\
334		.type = IIO_VOLTAGE,					\
335		.channel = num,						\
336		.address = addr,					\
337		.scan_index = index,					\
338		.scan_type = {						\
339			.sign = 'u',					\
340			.realbits = 14,					\
341			.storagebits = 16,				\
342		},							\
343		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
344		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
345		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
346				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
347		.info_mask_shared_by_all_available =			\
348				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
349		.datasheet_name = "CH"#num,				\
350		.indexed = 1,						\
351	}
352
353#define AT91_SAMA5D2_CHAN_DIFF(index, num, num2, addr)			\
354	{								\
355		.type = IIO_VOLTAGE,					\
356		.differential = 1,					\
357		.channel = num,						\
358		.channel2 = num2,					\
359		.address = addr,					\
360		.scan_index = index,					\
361		.scan_type = {						\
362			.sign = 's',					\
363			.realbits = 14,					\
364			.storagebits = 16,				\
365		},							\
366		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
367		.info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE),	\
368		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
369				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
370		.info_mask_shared_by_all_available =			\
371				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
372		.datasheet_name = "CH"#num"-CH"#num2,			\
373		.indexed = 1,						\
374	}
375
376#define AT91_SAMA5D2_CHAN_TOUCH(num, name, mod)				\
377	{								\
378		.type = IIO_POSITIONRELATIVE,				\
379		.modified = 1,						\
380		.channel = num,						\
381		.channel2 = mod,					\
382		.scan_index = num,					\
383		.scan_type = {						\
384			.sign = 'u',					\
385			.realbits = 12,					\
386			.storagebits = 16,				\
387		},							\
388		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
389		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
390				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
391		.info_mask_shared_by_all_available =			\
392				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
393		.datasheet_name = name,					\
394	}
395#define AT91_SAMA5D2_CHAN_PRESSURE(num, name)				\
396	{								\
397		.type = IIO_PRESSURE,					\
398		.channel = num,						\
399		.scan_index = num,					\
400		.scan_type = {						\
401			.sign = 'u',					\
402			.realbits = 12,					\
403			.storagebits = 16,				\
404		},							\
405		.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),		\
406		.info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ)|\
407				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
408		.info_mask_shared_by_all_available =			\
409				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
410		.datasheet_name = name,					\
411	}
412
413#define AT91_SAMA5D2_CHAN_TEMP(num, name, addr)				\
414	{								\
415		.type = IIO_TEMP,					\
416		.channel = num,						\
417		.address =  addr,					\
418		.scan_index = num,					\
419		.info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED),	\
420		.info_mask_shared_by_all =				\
421				BIT(IIO_CHAN_INFO_PROCESSED) |		\
422				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
423		.info_mask_shared_by_all_available =			\
424				BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO),	\
425		.datasheet_name = name,					\
426	}
427
428#define at91_adc_readl(st, reg)						\
429	readl_relaxed((st)->base + (st)->soc_info.platform->layout->reg)
430#define at91_adc_read_chan(st, reg)					\
431	readl_relaxed((st)->base + reg)
432#define at91_adc_writel(st, reg, val)					\
433	writel_relaxed(val, (st)->base + (st)->soc_info.platform->layout->reg)
434
435/**
436 * struct at91_adc_platform - at91-sama5d2 platform information struct
437 * @layout:		pointer to the reg layout struct
438 * @adc_channels:	pointer to an array of channels for registering in
439 *			the iio subsystem
440 * @nr_channels:	number of physical channels available
441 * @touch_chan_x:	index of the touchscreen X channel
442 * @touch_chan_y:	index of the touchscreen Y channel
443 * @touch_chan_p:	index of the touchscreen P channel
444 * @max_channels:	number of total channels
445 * @max_index:		highest channel index (highest index may be higher
446 *			than the total channel number)
447 * @hw_trig_cnt:	number of possible hardware triggers
448 * @osr_mask:		oversampling ratio bitmask on EMR register
449 * @oversampling_avail:	available oversampling values
450 * @oversampling_avail_no: number of available oversampling values
451 * @chan_realbits:	realbits for registered channels
452 * @temp_chan:		temperature channel index
453 * @temp_sensor:	temperature sensor supported
454 */
455struct at91_adc_platform {
456	const struct at91_adc_reg_layout	*layout;
457	const struct iio_chan_spec		(*adc_channels)[];
458	unsigned int				nr_channels;
459	unsigned int				touch_chan_x;
460	unsigned int				touch_chan_y;
461	unsigned int				touch_chan_p;
462	unsigned int				max_channels;
463	unsigned int				max_index;
464	unsigned int				hw_trig_cnt;
465	unsigned int				osr_mask;
466	unsigned int				oversampling_avail[5];
467	unsigned int				oversampling_avail_no;
468	unsigned int				chan_realbits;
469	unsigned int				temp_chan;
470	bool					temp_sensor;
471};
472
473/**
474 * struct at91_adc_temp_sensor_clb - at91-sama5d2 temperature sensor
475 * calibration data structure
476 * @p1: P1 calibration temperature
477 * @p4: P4 calibration voltage
478 * @p6: P6 calibration voltage
479 */
480struct at91_adc_temp_sensor_clb {
481	u32 p1;
482	u32 p4;
483	u32 p6;
484};
485
486/**
487 * enum at91_adc_ts_clb_idx - calibration indexes in NVMEM buffer
488 * @AT91_ADC_TS_CLB_IDX_P1: index for P1
489 * @AT91_ADC_TS_CLB_IDX_P4: index for P4
490 * @AT91_ADC_TS_CLB_IDX_P6: index for P6
491 * @AT91_ADC_TS_CLB_IDX_MAX: max index for temperature calibration packet in OTP
492 */
493enum at91_adc_ts_clb_idx {
494	AT91_ADC_TS_CLB_IDX_P1 = 2,
495	AT91_ADC_TS_CLB_IDX_P4 = 5,
496	AT91_ADC_TS_CLB_IDX_P6 = 7,
497	AT91_ADC_TS_CLB_IDX_MAX = 19,
498};
499
500/* Temperature sensor calibration - Vtemp voltage sensitivity to temperature. */
501#define AT91_ADC_TS_VTEMP_DT		(2080U)
502
503/**
504 * struct at91_adc_soc_info - at91-sama5d2 soc information struct
505 * @startup_time:	device startup time
506 * @min_sample_rate:	minimum sample rate in Hz
507 * @max_sample_rate:	maximum sample rate in Hz
508 * @platform:		pointer to the platform structure
509 * @temp_sensor_clb:	temperature sensor calibration data structure
510 */
511struct at91_adc_soc_info {
512	unsigned			startup_time;
513	unsigned			min_sample_rate;
514	unsigned			max_sample_rate;
515	const struct at91_adc_platform	*platform;
516	struct at91_adc_temp_sensor_clb	temp_sensor_clb;
517};
518
519struct at91_adc_trigger {
520	char				*name;
521	unsigned int			trgmod_value;
522	unsigned int			edge_type;
523	bool				hw_trig;
524};
525
526/**
527 * struct at91_adc_dma - at91-sama5d2 dma information struct
528 * @dma_chan:		the dma channel acquired
529 * @rx_buf:		dma coherent allocated area
530 * @rx_dma_buf:		dma handler for the buffer
531 * @phys_addr:		physical address of the ADC base register
532 * @buf_idx:		index inside the dma buffer where reading was last done
533 * @rx_buf_sz:		size of buffer used by DMA operation
534 * @watermark:		number of conversions to copy before DMA triggers irq
535 * @dma_ts:		hold the start timestamp of dma operation
536 */
537struct at91_adc_dma {
538	struct dma_chan			*dma_chan;
539	u8				*rx_buf;
540	dma_addr_t			rx_dma_buf;
541	phys_addr_t			phys_addr;
542	int				buf_idx;
543	int				rx_buf_sz;
544	int				watermark;
545	s64				dma_ts;
546};
547
548/**
549 * struct at91_adc_touch - at91-sama5d2 touchscreen information struct
550 * @sample_period_val:		the value for periodic trigger interval
551 * @touching:			is the pen touching the screen or not
552 * @x_pos:			temporary placeholder for pressure computation
553 * @channels_bitmask:		bitmask with the touchscreen channels enabled
554 * @workq:			workqueue for buffer data pushing
555 */
556struct at91_adc_touch {
557	u16				sample_period_val;
558	bool				touching;
559	u16				x_pos;
560	unsigned long			channels_bitmask;
561	struct work_struct		workq;
562};
563
564/**
565 * struct at91_adc_temp - at91-sama5d2 temperature information structure
566 * @sample_period_val:	sample period value
567 * @saved_sample_rate:	saved sample rate
568 * @saved_oversampling:	saved oversampling
569 */
570struct at91_adc_temp {
571	u16				sample_period_val;
572	u16				saved_sample_rate;
573	u16				saved_oversampling;
574};
575
576/*
577 * Buffer size requirements:
578 * No channels * bytes_per_channel(2) + timestamp bytes (8)
579 * Divided by 2 because we need half words.
580 * We assume 32 channels for now, has to be increased if needed.
581 * Nobody minds a buffer being too big.
582 */
583#define AT91_BUFFER_MAX_HWORDS ((32 * 2 + 8) / 2)
584
585struct at91_adc_state {
586	void __iomem			*base;
587	int				irq;
588	struct clk			*per_clk;
589	struct regulator		*reg;
590	struct regulator		*vref;
591	int				vref_uv;
592	unsigned int			current_sample_rate;
593	struct iio_trigger		*trig;
594	const struct at91_adc_trigger	*selected_trig;
595	const struct iio_chan_spec	*chan;
596	bool				conversion_done;
597	u32				conversion_value;
598	unsigned int			oversampling_ratio;
599	struct at91_adc_soc_info	soc_info;
600	wait_queue_head_t		wq_data_available;
601	struct at91_adc_dma		dma_st;
602	struct at91_adc_touch		touch_st;
603	struct at91_adc_temp		temp_st;
604	struct iio_dev			*indio_dev;
605	struct device			*dev;
606	/* Ensure naturally aligned timestamp */
607	u16				buffer[AT91_BUFFER_MAX_HWORDS] __aligned(8);
608	/*
609	 * lock to prevent concurrent 'single conversion' requests through
610	 * sysfs.
611	 */
612	struct mutex			lock;
613};
614
615static const struct at91_adc_trigger at91_adc_trigger_list[] = {
616	{
617		.name = "external_rising",
618		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_RISE,
619		.edge_type = IRQ_TYPE_EDGE_RISING,
620		.hw_trig = true,
621	},
622	{
623		.name = "external_falling",
624		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_FALL,
625		.edge_type = IRQ_TYPE_EDGE_FALLING,
626		.hw_trig = true,
627	},
628	{
629		.name = "external_any",
630		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_EXT_TRIG_ANY,
631		.edge_type = IRQ_TYPE_EDGE_BOTH,
632		.hw_trig = true,
633	},
634	{
635		.name = "software",
636		.trgmod_value = AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER,
637		.edge_type = IRQ_TYPE_NONE,
638		.hw_trig = false,
639	},
640};
641
642static const struct iio_chan_spec at91_sama5d2_adc_channels[] = {
643	AT91_SAMA5D2_CHAN_SINGLE(0, 0, 0x50),
644	AT91_SAMA5D2_CHAN_SINGLE(1, 1, 0x54),
645	AT91_SAMA5D2_CHAN_SINGLE(2, 2, 0x58),
646	AT91_SAMA5D2_CHAN_SINGLE(3, 3, 0x5c),
647	AT91_SAMA5D2_CHAN_SINGLE(4, 4, 0x60),
648	AT91_SAMA5D2_CHAN_SINGLE(5, 5, 0x64),
649	AT91_SAMA5D2_CHAN_SINGLE(6, 6, 0x68),
650	AT91_SAMA5D2_CHAN_SINGLE(7, 7, 0x6c),
651	AT91_SAMA5D2_CHAN_SINGLE(8, 8, 0x70),
652	AT91_SAMA5D2_CHAN_SINGLE(9, 9, 0x74),
653	AT91_SAMA5D2_CHAN_SINGLE(10, 10, 0x78),
654	AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x7c),
655	/* original ABI has the differential channels with a gap in between */
656	AT91_SAMA5D2_CHAN_DIFF(12, 0, 1, 0x50),
657	AT91_SAMA5D2_CHAN_DIFF(14, 2, 3, 0x58),
658	AT91_SAMA5D2_CHAN_DIFF(16, 4, 5, 0x60),
659	AT91_SAMA5D2_CHAN_DIFF(18, 6, 7, 0x68),
660	AT91_SAMA5D2_CHAN_DIFF(20, 8, 9, 0x70),
661	AT91_SAMA5D2_CHAN_DIFF(22, 10, 11, 0x78),
662	IIO_CHAN_SOFT_TIMESTAMP(23),
663	AT91_SAMA5D2_CHAN_TOUCH(24, "x", IIO_MOD_X),
664	AT91_SAMA5D2_CHAN_TOUCH(25, "y", IIO_MOD_Y),
665	AT91_SAMA5D2_CHAN_PRESSURE(26, "pressure"),
666};
667
668static const struct iio_chan_spec at91_sama7g5_adc_channels[] = {
669	AT91_SAMA5D2_CHAN_SINGLE(0, 0, 0x60),
670	AT91_SAMA5D2_CHAN_SINGLE(1, 1, 0x64),
671	AT91_SAMA5D2_CHAN_SINGLE(2, 2, 0x68),
672	AT91_SAMA5D2_CHAN_SINGLE(3, 3, 0x6c),
673	AT91_SAMA5D2_CHAN_SINGLE(4, 4, 0x70),
674	AT91_SAMA5D2_CHAN_SINGLE(5, 5, 0x74),
675	AT91_SAMA5D2_CHAN_SINGLE(6, 6, 0x78),
676	AT91_SAMA5D2_CHAN_SINGLE(7, 7, 0x7c),
677	AT91_SAMA5D2_CHAN_SINGLE(8, 8, 0x80),
678	AT91_SAMA5D2_CHAN_SINGLE(9, 9, 0x84),
679	AT91_SAMA5D2_CHAN_SINGLE(10, 10, 0x88),
680	AT91_SAMA5D2_CHAN_SINGLE(11, 11, 0x8c),
681	AT91_SAMA5D2_CHAN_SINGLE(12, 12, 0x90),
682	AT91_SAMA5D2_CHAN_SINGLE(13, 13, 0x94),
683	AT91_SAMA5D2_CHAN_SINGLE(14, 14, 0x98),
684	AT91_SAMA5D2_CHAN_SINGLE(15, 15, 0x9c),
685	AT91_SAMA5D2_CHAN_DIFF(16, 0, 1, 0x60),
686	AT91_SAMA5D2_CHAN_DIFF(17, 2, 3, 0x68),
687	AT91_SAMA5D2_CHAN_DIFF(18, 4, 5, 0x70),
688	AT91_SAMA5D2_CHAN_DIFF(19, 6, 7, 0x78),
689	AT91_SAMA5D2_CHAN_DIFF(20, 8, 9, 0x80),
690	AT91_SAMA5D2_CHAN_DIFF(21, 10, 11, 0x88),
691	AT91_SAMA5D2_CHAN_DIFF(22, 12, 13, 0x90),
692	AT91_SAMA5D2_CHAN_DIFF(23, 14, 15, 0x98),
693	IIO_CHAN_SOFT_TIMESTAMP(24),
694	AT91_SAMA5D2_CHAN_TEMP(AT91_SAMA7G5_ADC_TEMP_CHANNEL, "temp", 0xdc),
695};
696
697static const struct at91_adc_platform sama5d2_platform = {
698	.layout = &sama5d2_layout,
699	.adc_channels = &at91_sama5d2_adc_channels,
700#define AT91_SAMA5D2_SINGLE_CHAN_CNT 12
701#define AT91_SAMA5D2_DIFF_CHAN_CNT 6
702	.nr_channels = AT91_SAMA5D2_SINGLE_CHAN_CNT +
703		       AT91_SAMA5D2_DIFF_CHAN_CNT,
704#define AT91_SAMA5D2_TOUCH_X_CHAN_IDX	(AT91_SAMA5D2_SINGLE_CHAN_CNT + \
705					AT91_SAMA5D2_DIFF_CHAN_CNT * 2)
706	.touch_chan_x = AT91_SAMA5D2_TOUCH_X_CHAN_IDX,
707#define AT91_SAMA5D2_TOUCH_Y_CHAN_IDX	(AT91_SAMA5D2_TOUCH_X_CHAN_IDX + 1)
708	.touch_chan_y = AT91_SAMA5D2_TOUCH_Y_CHAN_IDX,
709#define AT91_SAMA5D2_TOUCH_P_CHAN_IDX	(AT91_SAMA5D2_TOUCH_Y_CHAN_IDX + 1)
710	.touch_chan_p = AT91_SAMA5D2_TOUCH_P_CHAN_IDX,
711#define AT91_SAMA5D2_MAX_CHAN_IDX	AT91_SAMA5D2_TOUCH_P_CHAN_IDX
712	.max_channels = ARRAY_SIZE(at91_sama5d2_adc_channels),
713	.max_index = AT91_SAMA5D2_MAX_CHAN_IDX,
714#define AT91_SAMA5D2_HW_TRIG_CNT	3
715	.hw_trig_cnt = AT91_SAMA5D2_HW_TRIG_CNT,
716	.osr_mask = GENMASK(17, 16),
717	.oversampling_avail = { 1, 4, 16, },
718	.oversampling_avail_no = 3,
719	.chan_realbits = 14,
720};
721
722static const struct at91_adc_platform sama7g5_platform = {
723	.layout = &sama7g5_layout,
724	.adc_channels = &at91_sama7g5_adc_channels,
725#define AT91_SAMA7G5_SINGLE_CHAN_CNT	16
726#define AT91_SAMA7G5_DIFF_CHAN_CNT	8
727#define AT91_SAMA7G5_TEMP_CHAN_CNT	1
728	.nr_channels = AT91_SAMA7G5_SINGLE_CHAN_CNT +
729		       AT91_SAMA7G5_DIFF_CHAN_CNT +
730		       AT91_SAMA7G5_TEMP_CHAN_CNT,
731#define AT91_SAMA7G5_MAX_CHAN_IDX	(AT91_SAMA7G5_SINGLE_CHAN_CNT + \
732					AT91_SAMA7G5_DIFF_CHAN_CNT + \
733					AT91_SAMA7G5_TEMP_CHAN_CNT)
734	.max_channels = ARRAY_SIZE(at91_sama7g5_adc_channels),
735	.max_index = AT91_SAMA7G5_MAX_CHAN_IDX,
736#define AT91_SAMA7G5_HW_TRIG_CNT	3
737	.hw_trig_cnt = AT91_SAMA7G5_HW_TRIG_CNT,
738	.osr_mask = GENMASK(18, 16),
739	.oversampling_avail = { 1, 4, 16, 64, 256, },
740	.oversampling_avail_no = 5,
741	.chan_realbits = 16,
742	.temp_sensor = true,
743	.temp_chan = AT91_SAMA7G5_ADC_TEMP_CHANNEL,
744};
745
746static int at91_adc_chan_xlate(struct iio_dev *indio_dev, int chan)
747{
748	int i;
749
750	for (i = 0; i < indio_dev->num_channels; i++) {
751		if (indio_dev->channels[i].scan_index == chan)
752			return i;
753	}
754	return -EINVAL;
755}
756
757static inline struct iio_chan_spec const *
758at91_adc_chan_get(struct iio_dev *indio_dev, int chan)
759{
760	int index = at91_adc_chan_xlate(indio_dev, chan);
761
762	if (index < 0)
763		return NULL;
764	return indio_dev->channels + index;
765}
766
767static inline int at91_adc_fwnode_xlate(struct iio_dev *indio_dev,
768					const struct fwnode_reference_args *iiospec)
769{
770	return at91_adc_chan_xlate(indio_dev, iiospec->args[0]);
771}
772
773static unsigned int at91_adc_active_scan_mask_to_reg(struct iio_dev *indio_dev)
774{
775	u32 mask = 0;
776	u8 bit;
777	struct at91_adc_state *st = iio_priv(indio_dev);
778
779	for_each_set_bit(bit, indio_dev->active_scan_mask,
780			 indio_dev->num_channels) {
781		struct iio_chan_spec const *chan =
782			 at91_adc_chan_get(indio_dev, bit);
783		mask |= BIT(chan->channel);
784	}
785
786	return mask & GENMASK(st->soc_info.platform->nr_channels, 0);
787}
788
789static void at91_adc_cor(struct at91_adc_state *st,
790			 struct iio_chan_spec const *chan)
791{
792	u32 cor, cur_cor;
793
794	cor = BIT(chan->channel) | BIT(chan->channel2);
795
796	cur_cor = at91_adc_readl(st, COR);
797	cor <<= st->soc_info.platform->layout->COR_diff_offset;
798	if (chan->differential)
799		at91_adc_writel(st, COR, cur_cor | cor);
800	else
801		at91_adc_writel(st, COR, cur_cor & ~cor);
802}
803
804static void at91_adc_irq_status(struct at91_adc_state *st, u32 *status,
805				u32 *eoc)
806{
807	*status = at91_adc_readl(st, ISR);
808	if (st->soc_info.platform->layout->EOC_ISR)
809		*eoc = at91_adc_readl(st, EOC_ISR);
810	else
811		*eoc = *status;
812}
813
814static void at91_adc_irq_mask(struct at91_adc_state *st, u32 *status, u32 *eoc)
815{
816	*status = at91_adc_readl(st, IMR);
817	if (st->soc_info.platform->layout->EOC_IMR)
818		*eoc = at91_adc_readl(st, EOC_IMR);
819	else
820		*eoc = *status;
821}
822
823static void at91_adc_eoc_dis(struct at91_adc_state *st, unsigned int channel)
824{
825	/*
826	 * On some products having the EOC bits in a separate register,
827	 * errata recommends not writing this register (EOC_IDR).
828	 * On products having the EOC bits in the IDR register, it's fine to write it.
829	 */
830	if (!st->soc_info.platform->layout->EOC_IDR)
831		at91_adc_writel(st, IDR, BIT(channel));
832}
833
834static void at91_adc_eoc_ena(struct at91_adc_state *st, unsigned int channel)
835{
836	if (!st->soc_info.platform->layout->EOC_IDR)
837		at91_adc_writel(st, IER, BIT(channel));
838	else
839		at91_adc_writel(st, EOC_IER, BIT(channel));
840}
841
842static int at91_adc_config_emr(struct at91_adc_state *st,
843			       u32 oversampling_ratio, u32 trackx)
844{
845	/* configure the extended mode register */
846	unsigned int emr, osr;
847	unsigned int osr_mask = st->soc_info.platform->osr_mask;
848	int i, ret;
849
850	/* Check against supported oversampling values. */
851	for (i = 0; i < st->soc_info.platform->oversampling_avail_no; i++) {
852		if (oversampling_ratio == st->soc_info.platform->oversampling_avail[i])
853			break;
854	}
855	if (i == st->soc_info.platform->oversampling_avail_no)
856		return -EINVAL;
857
858	/* select oversampling ratio from configuration */
859	switch (oversampling_ratio) {
860	case 1:
861		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_1SAMPLES,
862					   osr_mask);
863		break;
864	case 4:
865		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_4SAMPLES,
866					   osr_mask);
867		break;
868	case 16:
869		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_16SAMPLES,
870					   osr_mask);
871		break;
872	case 64:
873		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_64SAMPLES,
874					   osr_mask);
875		break;
876	case 256:
877		osr = AT91_SAMA5D2_EMR_OSR(AT91_SAMA5D2_EMR_OSR_256SAMPLES,
878					   osr_mask);
879		break;
880	}
881
882	ret = pm_runtime_resume_and_get(st->dev);
883	if (ret < 0)
884		return ret;
885
886	emr = at91_adc_readl(st, EMR);
887	/* select oversampling per single trigger event */
888	emr |= AT91_SAMA5D2_EMR_ASTE(1);
889	/* delete leftover content if it's the case */
890	emr &= ~(osr_mask | AT91_SAMA5D2_TRACKX_MASK);
891	/* Update osr and trackx. */
892	emr |= osr | AT91_SAMA5D2_TRACKX(trackx);
893	at91_adc_writel(st, EMR, emr);
894
895	pm_runtime_mark_last_busy(st->dev);
896	pm_runtime_put_autosuspend(st->dev);
897
898	st->oversampling_ratio = oversampling_ratio;
899
900	return 0;
901}
902
903static int at91_adc_adjust_val_osr(struct at91_adc_state *st, int *val)
904{
905	int nbits, diff;
906
907	if (st->oversampling_ratio == 1)
908		nbits = 12;
909	else if (st->oversampling_ratio == 4)
910		nbits = 13;
911	else if (st->oversampling_ratio == 16)
912		nbits = 14;
913	else if (st->oversampling_ratio == 64)
914		nbits = 15;
915	else if (st->oversampling_ratio == 256)
916		nbits = 16;
917	else
918		/* Should not happen. */
919		return -EINVAL;
920
921	/*
922	 * We have nbits of real data and channel is registered as
923	 * st->soc_info.platform->chan_realbits, so shift left diff bits.
924	 */
925	diff = st->soc_info.platform->chan_realbits - nbits;
926	*val <<= diff;
927
928	return IIO_VAL_INT;
929}
930
931static void at91_adc_adjust_val_osr_array(struct at91_adc_state *st, void *buf,
932					  int len)
933{
934	int i = 0, val;
935	u16 *buf_u16 = (u16 *) buf;
936
937	/*
938	 * We are converting each two bytes (each sample).
939	 * First convert the byte based array to u16, and convert each sample
940	 * separately.
941	 * Each value is two bytes in an array of chars, so to not shift
942	 * more than we need, save the value separately.
943	 * len is in bytes, so divide by two to get number of samples.
944	 */
945	while (i < len / 2) {
946		val = buf_u16[i];
947		at91_adc_adjust_val_osr(st, &val);
948		buf_u16[i] = val;
949		i++;
950	}
951}
952
953static int at91_adc_configure_touch(struct at91_adc_state *st, bool state)
954{
955	u32 clk_khz = st->current_sample_rate / 1000;
956	int i = 0, ret;
957	u16 pendbc;
958	u32 tsmr, acr;
959
960	if (state) {
961		ret = pm_runtime_resume_and_get(st->dev);
962		if (ret < 0)
963			return ret;
964	} else {
965		/* disabling touch IRQs and setting mode to no touch enabled */
966		at91_adc_writel(st, IDR,
967				AT91_SAMA5D2_IER_PEN | AT91_SAMA5D2_IER_NOPEN);
968		at91_adc_writel(st, TSMR, 0);
969
970		pm_runtime_mark_last_busy(st->dev);
971		pm_runtime_put_autosuspend(st->dev);
972		return 0;
973	}
974	/*
975	 * debounce time is in microseconds, we need it in milliseconds to
976	 * multiply with kilohertz, so, divide by 1000, but after the multiply.
977	 * round up to make sure pendbc is at least 1
978	 */
979	pendbc = round_up(AT91_SAMA5D2_TOUCH_PEN_DETECT_DEBOUNCE_US *
980			  clk_khz / 1000, 1);
981
982	/* get the required exponent */
983	while (pendbc >> i++)
984		;
985
986	pendbc = i;
987
988	tsmr = AT91_SAMA5D2_TSMR_TSMODE_4WIRE_PRESS;
989
990	tsmr |= AT91_SAMA5D2_TSMR_TSAV(2) & AT91_SAMA5D2_TSMR_TSAV_MASK;
991	tsmr |= AT91_SAMA5D2_TSMR_PENDBC(pendbc) &
992		AT91_SAMA5D2_TSMR_PENDBC_MASK;
993	tsmr |= AT91_SAMA5D2_TSMR_NOTSDMA;
994	tsmr |= AT91_SAMA5D2_TSMR_PENDET_ENA;
995	tsmr |= AT91_SAMA5D2_TSMR_TSFREQ(2) & AT91_SAMA5D2_TSMR_TSFREQ_MASK;
996
997	at91_adc_writel(st, TSMR, tsmr);
998
999	acr =  at91_adc_readl(st, ACR);
1000	acr &= ~AT91_SAMA5D2_ACR_PENDETSENS_MASK;
1001	acr |= 0x02 & AT91_SAMA5D2_ACR_PENDETSENS_MASK;
1002	at91_adc_writel(st, ACR, acr);
1003
1004	/* Sample Period Time = (TRGPER + 1) / ADCClock */
1005	st->touch_st.sample_period_val =
1006				 round_up((AT91_SAMA5D2_TOUCH_SAMPLE_PERIOD_US *
1007				 clk_khz / 1000) - 1, 1);
1008	/* enable pen detect IRQ */
1009	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN);
1010
1011	return 0;
1012}
1013
1014static u16 at91_adc_touch_pos(struct at91_adc_state *st, int reg)
1015{
1016	u32 val = 0;
1017	u32 scale, result, pos;
1018
1019	/*
1020	 * to obtain the actual position we must divide by scale
1021	 * and multiply with max, where
1022	 * max = 2^AT91_SAMA5D2_MAX_POS_BITS - 1
1023	 */
1024	/* first half of register is the x or y, second half is the scale */
1025	if (reg == st->soc_info.platform->layout->XPOSR)
1026		val = at91_adc_readl(st, XPOSR);
1027	else if (reg == st->soc_info.platform->layout->YPOSR)
1028		val = at91_adc_readl(st, YPOSR);
1029
1030	if (!val)
1031		dev_dbg(&st->indio_dev->dev, "pos is 0\n");
1032
1033	pos = val & AT91_SAMA5D2_XYZ_MASK;
1034	result = (pos << AT91_SAMA5D2_MAX_POS_BITS) - pos;
1035	scale = (val >> 16) & AT91_SAMA5D2_XYZ_MASK;
1036	if (scale == 0) {
1037		dev_err(&st->indio_dev->dev, "scale is 0\n");
1038		return 0;
1039	}
1040	result /= scale;
1041
1042	return result;
1043}
1044
1045static u16 at91_adc_touch_x_pos(struct at91_adc_state *st)
1046{
1047	st->touch_st.x_pos = at91_adc_touch_pos(st, st->soc_info.platform->layout->XPOSR);
1048	return st->touch_st.x_pos;
1049}
1050
1051static u16 at91_adc_touch_y_pos(struct at91_adc_state *st)
1052{
1053	return at91_adc_touch_pos(st, st->soc_info.platform->layout->YPOSR);
1054}
1055
1056static u16 at91_adc_touch_pressure(struct at91_adc_state *st)
1057{
1058	u32 val;
1059	u32 z1, z2;
1060	u32 pres;
1061	u32 rxp = 1;
1062	u32 factor = 1000;
1063
1064	/* calculate the pressure */
1065	val = at91_adc_readl(st, PRESSR);
1066	z1 = val & AT91_SAMA5D2_XYZ_MASK;
1067	z2 = (val >> 16) & AT91_SAMA5D2_XYZ_MASK;
1068
1069	if (z1 != 0)
1070		pres = rxp * (st->touch_st.x_pos * factor / 1024) *
1071			(z2 * factor / z1 - factor) /
1072			factor;
1073	else
1074		pres = 0xFFFF;       /* no pen contact */
1075
1076	/*
1077	 * The pressure from device grows down, minimum is 0xFFFF, maximum 0x0.
1078	 * We compute it this way, but let's return it in the expected way,
1079	 * growing from 0 to 0xFFFF.
1080	 */
1081	return 0xFFFF - pres;
1082}
1083
1084static int at91_adc_read_position(struct at91_adc_state *st, int chan, u16 *val)
1085{
1086	*val = 0;
1087	if (!st->touch_st.touching)
1088		return -ENODATA;
1089	if (chan == st->soc_info.platform->touch_chan_x)
1090		*val = at91_adc_touch_x_pos(st);
1091	else if (chan == st->soc_info.platform->touch_chan_y)
1092		*val = at91_adc_touch_y_pos(st);
1093	else
1094		return -ENODATA;
1095
1096	return IIO_VAL_INT;
1097}
1098
1099static int at91_adc_read_pressure(struct at91_adc_state *st, int chan, u16 *val)
1100{
1101	*val = 0;
1102	if (!st->touch_st.touching)
1103		return -ENODATA;
1104	if (chan == st->soc_info.platform->touch_chan_p)
1105		*val = at91_adc_touch_pressure(st);
1106	else
1107		return -ENODATA;
1108
1109	return IIO_VAL_INT;
1110}
1111
1112static void at91_adc_configure_trigger_registers(struct at91_adc_state *st,
1113						 bool state)
1114{
1115	u32 status = at91_adc_readl(st, TRGR);
1116
1117	/* clear TRGMOD */
1118	status &= ~AT91_SAMA5D2_TRGR_TRGMOD_MASK;
1119
1120	if (state)
1121		status |= st->selected_trig->trgmod_value;
1122
1123	/* set/unset hw trigger */
1124	at91_adc_writel(st, TRGR, status);
1125}
1126
1127static int at91_adc_configure_trigger(struct iio_trigger *trig, bool state)
1128{
1129	struct iio_dev *indio = iio_trigger_get_drvdata(trig);
1130	struct at91_adc_state *st = iio_priv(indio);
1131	int ret;
1132
1133	if (state) {
1134		ret = pm_runtime_resume_and_get(st->dev);
1135		if (ret < 0)
1136			return ret;
1137	}
1138
1139	at91_adc_configure_trigger_registers(st, state);
1140
1141	if (!state) {
1142		pm_runtime_mark_last_busy(st->dev);
1143		pm_runtime_put_autosuspend(st->dev);
1144	}
1145
1146	return 0;
1147}
1148
1149static void at91_adc_reenable_trigger(struct iio_trigger *trig)
1150{
1151	struct iio_dev *indio = iio_trigger_get_drvdata(trig);
1152	struct at91_adc_state *st = iio_priv(indio);
1153
1154	/* if we are using DMA, we must not reenable irq after each trigger */
1155	if (st->dma_st.dma_chan)
1156		return;
1157
1158	enable_irq(st->irq);
1159
1160	/* Needed to ACK the DRDY interruption */
1161	at91_adc_readl(st, LCDR);
1162}
1163
1164static const struct iio_trigger_ops at91_adc_trigger_ops = {
1165	.set_trigger_state = &at91_adc_configure_trigger,
1166	.reenable = &at91_adc_reenable_trigger,
1167	.validate_device = iio_trigger_validate_own_device,
1168};
1169
1170static int at91_adc_dma_size_done(struct at91_adc_state *st)
1171{
1172	struct dma_tx_state state;
1173	enum dma_status status;
1174	int i, size;
1175
1176	status = dmaengine_tx_status(st->dma_st.dma_chan,
1177				     st->dma_st.dma_chan->cookie,
1178				     &state);
1179	if (status != DMA_IN_PROGRESS)
1180		return 0;
1181
1182	/* Transferred length is size in bytes from end of buffer */
1183	i = st->dma_st.rx_buf_sz - state.residue;
1184
1185	/* Return available bytes */
1186	if (i >= st->dma_st.buf_idx)
1187		size = i - st->dma_st.buf_idx;
1188	else
1189		size = st->dma_st.rx_buf_sz + i - st->dma_st.buf_idx;
1190	return size;
1191}
1192
1193static void at91_dma_buffer_done(void *data)
1194{
1195	struct iio_dev *indio_dev = data;
1196
1197	iio_trigger_poll_nested(indio_dev->trig);
1198}
1199
1200static int at91_adc_dma_start(struct iio_dev *indio_dev)
1201{
1202	struct at91_adc_state *st = iio_priv(indio_dev);
1203	struct dma_async_tx_descriptor *desc;
1204	dma_cookie_t cookie;
1205	int ret;
1206	u8 bit;
1207
1208	if (!st->dma_st.dma_chan)
1209		return 0;
1210
1211	/* we start a new DMA, so set buffer index to start */
1212	st->dma_st.buf_idx = 0;
1213
1214	/*
1215	 * compute buffer size w.r.t. watermark and enabled channels.
1216	 * scan_bytes is aligned so we need an exact size for DMA
1217	 */
1218	st->dma_st.rx_buf_sz = 0;
1219
1220	for_each_set_bit(bit, indio_dev->active_scan_mask,
1221			 indio_dev->num_channels) {
1222		struct iio_chan_spec const *chan =
1223					 at91_adc_chan_get(indio_dev, bit);
1224
1225		if (!chan)
1226			continue;
1227
1228		st->dma_st.rx_buf_sz += chan->scan_type.storagebits / 8;
1229	}
1230	st->dma_st.rx_buf_sz *= st->dma_st.watermark;
1231
1232	/* Prepare a DMA cyclic transaction */
1233	desc = dmaengine_prep_dma_cyclic(st->dma_st.dma_chan,
1234					 st->dma_st.rx_dma_buf,
1235					 st->dma_st.rx_buf_sz,
1236					 st->dma_st.rx_buf_sz / 2,
1237					 DMA_DEV_TO_MEM, DMA_PREP_INTERRUPT);
1238
1239	if (!desc) {
1240		dev_err(&indio_dev->dev, "cannot prepare DMA cyclic\n");
1241		return -EBUSY;
1242	}
1243
1244	desc->callback = at91_dma_buffer_done;
1245	desc->callback_param = indio_dev;
1246
1247	cookie = dmaengine_submit(desc);
1248	ret = dma_submit_error(cookie);
1249	if (ret) {
1250		dev_err(&indio_dev->dev, "cannot submit DMA cyclic\n");
1251		dmaengine_terminate_async(st->dma_st.dma_chan);
1252		return ret;
1253	}
1254
1255	/* enable general overrun error signaling */
1256	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_GOVRE);
1257	/* Issue pending DMA requests */
1258	dma_async_issue_pending(st->dma_st.dma_chan);
1259
1260	/* consider current time as DMA start time for timestamps */
1261	st->dma_st.dma_ts = iio_get_time_ns(indio_dev);
1262
1263	dev_dbg(&indio_dev->dev, "DMA cyclic started\n");
1264
1265	return 0;
1266}
1267
1268static bool at91_adc_buffer_check_use_irq(struct iio_dev *indio,
1269					  struct at91_adc_state *st)
1270{
1271	/* if using DMA, we do not use our own IRQ (we use DMA-controller) */
1272	if (st->dma_st.dma_chan)
1273		return false;
1274	/* if the trigger is not ours, then it has its own IRQ */
1275	if (iio_trigger_validate_own_device(indio->trig, indio))
1276		return false;
1277	return true;
1278}
1279
1280static bool at91_adc_current_chan_is_touch(struct iio_dev *indio_dev)
1281{
1282	struct at91_adc_state *st = iio_priv(indio_dev);
1283
1284	return !!bitmap_subset(indio_dev->active_scan_mask,
1285			       &st->touch_st.channels_bitmask,
1286			       st->soc_info.platform->max_index + 1);
1287}
1288
1289static int at91_adc_buffer_prepare(struct iio_dev *indio_dev)
1290{
1291	int ret;
1292	u8 bit;
1293	struct at91_adc_state *st = iio_priv(indio_dev);
1294
1295	/* check if we are enabling triggered buffer or the touchscreen */
1296	if (at91_adc_current_chan_is_touch(indio_dev))
1297		return at91_adc_configure_touch(st, true);
1298
1299	/* if we are not in triggered mode, we cannot enable the buffer. */
1300	if (!(iio_device_get_current_mode(indio_dev) & INDIO_ALL_TRIGGERED_MODES))
1301		return -EINVAL;
1302
1303	ret = pm_runtime_resume_and_get(st->dev);
1304	if (ret < 0)
1305		return ret;
1306
1307	/* we continue with the triggered buffer */
1308	ret = at91_adc_dma_start(indio_dev);
1309	if (ret) {
1310		dev_err(&indio_dev->dev, "buffer prepare failed\n");
1311		goto pm_runtime_put;
1312	}
1313
1314	for_each_set_bit(bit, indio_dev->active_scan_mask,
1315			 indio_dev->num_channels) {
1316		struct iio_chan_spec const *chan =
1317					at91_adc_chan_get(indio_dev, bit);
1318		if (!chan)
1319			continue;
1320		/* these channel types cannot be handled by this trigger */
1321		if (chan->type == IIO_POSITIONRELATIVE ||
1322		    chan->type == IIO_PRESSURE ||
1323		    chan->type == IIO_TEMP)
1324			continue;
1325
1326		at91_adc_cor(st, chan);
1327
1328		at91_adc_writel(st, CHER, BIT(chan->channel));
1329	}
1330
1331	if (at91_adc_buffer_check_use_irq(indio_dev, st))
1332		at91_adc_writel(st, IER, AT91_SAMA5D2_IER_DRDY);
1333
1334pm_runtime_put:
1335	pm_runtime_mark_last_busy(st->dev);
1336	pm_runtime_put_autosuspend(st->dev);
1337	return ret;
1338}
1339
1340static int at91_adc_buffer_postdisable(struct iio_dev *indio_dev)
1341{
1342	struct at91_adc_state *st = iio_priv(indio_dev);
1343	int ret;
1344	u8 bit;
1345
1346	/* check if we are disabling triggered buffer or the touchscreen */
1347	if (at91_adc_current_chan_is_touch(indio_dev))
1348		return at91_adc_configure_touch(st, false);
1349
1350	/* if we are not in triggered mode, nothing to do here */
1351	if (!(iio_device_get_current_mode(indio_dev) & INDIO_ALL_TRIGGERED_MODES))
1352		return -EINVAL;
1353
1354	ret = pm_runtime_resume_and_get(st->dev);
1355	if (ret < 0)
1356		return ret;
1357
1358	/*
1359	 * For each enable channel we must disable it in hardware.
1360	 * In the case of DMA, we must read the last converted value
1361	 * to clear EOC status and not get a possible interrupt later.
1362	 * This value is being read by DMA from LCDR anyway, so it's not lost.
1363	 */
1364	for_each_set_bit(bit, indio_dev->active_scan_mask,
1365			 indio_dev->num_channels) {
1366		struct iio_chan_spec const *chan =
1367					at91_adc_chan_get(indio_dev, bit);
1368
1369		if (!chan)
1370			continue;
1371		/* these channel types are virtual, no need to do anything */
1372		if (chan->type == IIO_POSITIONRELATIVE ||
1373		    chan->type == IIO_PRESSURE ||
1374		    chan->type == IIO_TEMP)
1375			continue;
1376
1377		at91_adc_writel(st, CHDR, BIT(chan->channel));
1378
1379		if (st->dma_st.dma_chan)
1380			at91_adc_read_chan(st, chan->address);
1381	}
1382
1383	if (at91_adc_buffer_check_use_irq(indio_dev, st))
1384		at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_DRDY);
1385
1386	/* read overflow register to clear possible overflow status */
1387	at91_adc_readl(st, OVER);
1388
1389	/* if we are using DMA we must clear registers and end DMA */
1390	if (st->dma_st.dma_chan)
1391		dmaengine_terminate_sync(st->dma_st.dma_chan);
1392
1393	pm_runtime_mark_last_busy(st->dev);
1394	pm_runtime_put_autosuspend(st->dev);
1395
1396	return 0;
1397}
1398
1399static const struct iio_buffer_setup_ops at91_buffer_setup_ops = {
1400	.postdisable = &at91_adc_buffer_postdisable,
1401};
1402
1403static struct iio_trigger *at91_adc_allocate_trigger(struct iio_dev *indio,
1404						     char *trigger_name)
1405{
1406	struct iio_trigger *trig;
1407	int ret;
1408
1409	trig = devm_iio_trigger_alloc(&indio->dev, "%s-dev%d-%s", indio->name,
1410				iio_device_id(indio), trigger_name);
1411	if (!trig)
1412		return ERR_PTR(-ENOMEM);
1413
1414	trig->dev.parent = indio->dev.parent;
1415	iio_trigger_set_drvdata(trig, indio);
1416	trig->ops = &at91_adc_trigger_ops;
1417
1418	ret = devm_iio_trigger_register(&indio->dev, trig);
1419	if (ret)
1420		return ERR_PTR(ret);
1421
1422	return trig;
1423}
1424
1425static void at91_adc_trigger_handler_nodma(struct iio_dev *indio_dev,
1426					   struct iio_poll_func *pf)
1427{
1428	struct at91_adc_state *st = iio_priv(indio_dev);
1429	int i = 0;
1430	int val;
1431	u8 bit;
1432	u32 mask = at91_adc_active_scan_mask_to_reg(indio_dev);
1433	unsigned int timeout = 50;
1434	u32 status, imr, eoc = 0, eoc_imr;
1435
1436	/*
1437	 * Check if the conversion is ready. If not, wait a little bit, and
1438	 * in case of timeout exit with an error.
1439	 */
1440	while (((eoc & mask) != mask) && timeout) {
1441		at91_adc_irq_status(st, &status, &eoc);
1442		at91_adc_irq_mask(st, &imr, &eoc_imr);
1443		usleep_range(50, 100);
1444		timeout--;
1445	}
1446
1447	/* Cannot read data, not ready. Continue without reporting data */
1448	if (!timeout)
1449		return;
1450
1451	for_each_set_bit(bit, indio_dev->active_scan_mask,
1452			 indio_dev->num_channels) {
1453		struct iio_chan_spec const *chan =
1454					at91_adc_chan_get(indio_dev, bit);
1455
1456		if (!chan)
1457			continue;
1458		/*
1459		 * Our external trigger only supports the voltage channels.
1460		 * In case someone requested a different type of channel
1461		 * just put zeroes to buffer.
1462		 * This should not happen because we check the scan mode
1463		 * and scan mask when we enable the buffer, and we don't allow
1464		 * the buffer to start with a mixed mask (voltage and something
1465		 * else).
1466		 * Thus, emit a warning.
1467		 */
1468		if (chan->type == IIO_VOLTAGE) {
1469			val = at91_adc_read_chan(st, chan->address);
1470			at91_adc_adjust_val_osr(st, &val);
1471			st->buffer[i] = val;
1472		} else {
1473			st->buffer[i] = 0;
1474			WARN(true, "This trigger cannot handle this type of channel");
1475		}
1476		i++;
1477	}
1478	iio_push_to_buffers_with_timestamp(indio_dev, st->buffer,
1479					   pf->timestamp);
1480}
1481
1482static void at91_adc_trigger_handler_dma(struct iio_dev *indio_dev)
1483{
1484	struct at91_adc_state *st = iio_priv(indio_dev);
1485	int transferred_len = at91_adc_dma_size_done(st);
1486	s64 ns = iio_get_time_ns(indio_dev);
1487	s64 interval;
1488	int sample_index = 0, sample_count, sample_size;
1489
1490	u32 status = at91_adc_readl(st, ISR);
1491	/* if we reached this point, we cannot sample faster */
1492	if (status & AT91_SAMA5D2_IER_GOVRE)
1493		pr_info_ratelimited("%s: conversion overrun detected\n",
1494				    indio_dev->name);
1495
1496	sample_size = div_s64(st->dma_st.rx_buf_sz, st->dma_st.watermark);
1497
1498	sample_count = div_s64(transferred_len, sample_size);
1499
1500	/*
1501	 * interval between samples is total time since last transfer handling
1502	 * divided by the number of samples (total size divided by sample size)
1503	 */
1504	interval = div_s64((ns - st->dma_st.dma_ts), sample_count);
1505
1506	while (transferred_len >= sample_size) {
1507		/*
1508		 * for all the values in the current sample,
1509		 * adjust the values inside the buffer for oversampling
1510		 */
1511		at91_adc_adjust_val_osr_array(st,
1512					&st->dma_st.rx_buf[st->dma_st.buf_idx],
1513					sample_size);
1514
1515		iio_push_to_buffers_with_timestamp(indio_dev,
1516				(st->dma_st.rx_buf + st->dma_st.buf_idx),
1517				(st->dma_st.dma_ts + interval * sample_index));
1518		/* adjust remaining length */
1519		transferred_len -= sample_size;
1520		/* adjust buffer index */
1521		st->dma_st.buf_idx += sample_size;
1522		/* in case of reaching end of buffer, reset index */
1523		if (st->dma_st.buf_idx >= st->dma_st.rx_buf_sz)
1524			st->dma_st.buf_idx = 0;
1525		sample_index++;
1526	}
1527	/* adjust saved time for next transfer handling */
1528	st->dma_st.dma_ts = iio_get_time_ns(indio_dev);
1529}
1530
1531static irqreturn_t at91_adc_trigger_handler(int irq, void *p)
1532{
1533	struct iio_poll_func *pf = p;
1534	struct iio_dev *indio_dev = pf->indio_dev;
1535	struct at91_adc_state *st = iio_priv(indio_dev);
1536
1537	/*
1538	 * If it's not our trigger, start a conversion now, as we are
1539	 * actually polling the trigger now.
1540	 */
1541	if (iio_trigger_validate_own_device(indio_dev->trig, indio_dev))
1542		at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START);
1543
1544	if (st->dma_st.dma_chan)
1545		at91_adc_trigger_handler_dma(indio_dev);
1546	else
1547		at91_adc_trigger_handler_nodma(indio_dev, pf);
1548
1549	iio_trigger_notify_done(indio_dev->trig);
1550
1551	return IRQ_HANDLED;
1552}
1553
1554static unsigned at91_adc_startup_time(unsigned startup_time_min,
1555				      unsigned adc_clk_khz)
1556{
1557	static const unsigned int startup_lookup[] = {
1558		  0,   8,  16,  24,
1559		 64,  80,  96, 112,
1560		512, 576, 640, 704,
1561		768, 832, 896, 960
1562		};
1563	unsigned ticks_min, i;
1564
1565	/*
1566	 * Since the adc frequency is checked before, there is no reason
1567	 * to not meet the startup time constraint.
1568	 */
1569
1570	ticks_min = startup_time_min * adc_clk_khz / 1000;
1571	for (i = 0; i < ARRAY_SIZE(startup_lookup); i++)
1572		if (startup_lookup[i] > ticks_min)
1573			break;
1574
1575	return i;
1576}
1577
1578static void at91_adc_setup_samp_freq(struct iio_dev *indio_dev, unsigned freq,
1579				     unsigned int startup_time,
1580				     unsigned int tracktim)
1581{
1582	struct at91_adc_state *st = iio_priv(indio_dev);
1583	unsigned f_per, prescal, startup, mr;
1584	int ret;
1585
1586	f_per = clk_get_rate(st->per_clk);
1587	prescal = (f_per / (2 * freq)) - 1;
1588
1589	startup = at91_adc_startup_time(startup_time, freq / 1000);
1590
1591	ret = pm_runtime_resume_and_get(st->dev);
1592	if (ret < 0)
1593		return;
1594
1595	mr = at91_adc_readl(st, MR);
1596	mr &= ~(AT91_SAMA5D2_MR_STARTUP_MASK | AT91_SAMA5D2_MR_PRESCAL_MASK);
1597	mr |= AT91_SAMA5D2_MR_STARTUP(startup);
1598	mr |= AT91_SAMA5D2_MR_PRESCAL(prescal);
1599	mr |= AT91_SAMA5D2_MR_TRACKTIM(tracktim);
1600	at91_adc_writel(st, MR, mr);
1601
1602	pm_runtime_mark_last_busy(st->dev);
1603	pm_runtime_put_autosuspend(st->dev);
1604
1605	dev_dbg(&indio_dev->dev, "freq: %u, startup: %u, prescal: %u, tracktim=%u\n",
1606		freq, startup, prescal, tracktim);
1607	st->current_sample_rate = freq;
1608}
1609
1610static inline unsigned at91_adc_get_sample_freq(struct at91_adc_state *st)
1611{
1612	return st->current_sample_rate;
1613}
1614
1615static void at91_adc_touch_data_handler(struct iio_dev *indio_dev)
1616{
1617	struct at91_adc_state *st = iio_priv(indio_dev);
1618	u8 bit;
1619	u16 val;
1620	int i = 0;
1621
1622	for_each_set_bit(bit, indio_dev->active_scan_mask,
1623			 st->soc_info.platform->max_index + 1) {
1624		struct iio_chan_spec const *chan =
1625					 at91_adc_chan_get(indio_dev, bit);
1626
1627		if (chan->type == IIO_POSITIONRELATIVE)
1628			at91_adc_read_position(st, chan->channel, &val);
1629		else if (chan->type == IIO_PRESSURE)
1630			at91_adc_read_pressure(st, chan->channel, &val);
1631		else
1632			continue;
1633		st->buffer[i] = val;
1634		i++;
1635	}
1636	/*
1637	 * Schedule work to push to buffers.
1638	 * This is intended to push to the callback buffer that another driver
1639	 * registered. We are still in a handler from our IRQ. If we push
1640	 * directly, it means the other driver has it's callback called
1641	 * from our IRQ context. Which is something we better avoid.
1642	 * Let's schedule it after our IRQ is completed.
1643	 */
1644	schedule_work(&st->touch_st.workq);
1645}
1646
1647static void at91_adc_pen_detect_interrupt(struct at91_adc_state *st)
1648{
1649	at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_PEN);
1650	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_NOPEN |
1651			AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
1652			AT91_SAMA5D2_IER_PRDY);
1653	at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_PERIODIC |
1654			AT91_SAMA5D2_TRGR_TRGPER(st->touch_st.sample_period_val));
1655	st->touch_st.touching = true;
1656}
1657
1658static void at91_adc_no_pen_detect_interrupt(struct iio_dev *indio_dev)
1659{
1660	struct at91_adc_state *st = iio_priv(indio_dev);
1661
1662	at91_adc_writel(st, TRGR, AT91_SAMA5D2_TRGR_TRGMOD_NO_TRIGGER);
1663	at91_adc_writel(st, IDR, AT91_SAMA5D2_IER_NOPEN |
1664			AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
1665			AT91_SAMA5D2_IER_PRDY);
1666	st->touch_st.touching = false;
1667
1668	at91_adc_touch_data_handler(indio_dev);
1669
1670	at91_adc_writel(st, IER, AT91_SAMA5D2_IER_PEN);
1671}
1672
1673static void at91_adc_workq_handler(struct work_struct *workq)
1674{
1675	struct at91_adc_touch *touch_st = container_of(workq,
1676					struct at91_adc_touch, workq);
1677	struct at91_adc_state *st = container_of(touch_st,
1678					struct at91_adc_state, touch_st);
1679	struct iio_dev *indio_dev = st->indio_dev;
1680
1681	iio_push_to_buffers(indio_dev, st->buffer);
1682}
1683
1684static irqreturn_t at91_adc_interrupt(int irq, void *private)
1685{
1686	struct iio_dev *indio = private;
1687	struct at91_adc_state *st = iio_priv(indio);
1688	u32 status, eoc, imr, eoc_imr;
1689	u32 rdy_mask = AT91_SAMA5D2_IER_XRDY | AT91_SAMA5D2_IER_YRDY |
1690			AT91_SAMA5D2_IER_PRDY;
1691
1692	at91_adc_irq_status(st, &status, &eoc);
1693	at91_adc_irq_mask(st, &imr, &eoc_imr);
1694
1695	if (!(status & imr) && !(eoc & eoc_imr))
1696		return IRQ_NONE;
1697	if (status & AT91_SAMA5D2_IER_PEN) {
1698		/* pen detected IRQ */
1699		at91_adc_pen_detect_interrupt(st);
1700	} else if ((status & AT91_SAMA5D2_IER_NOPEN)) {
1701		/* nopen detected IRQ */
1702		at91_adc_no_pen_detect_interrupt(indio);
1703	} else if ((status & AT91_SAMA5D2_ISR_PENS) &&
1704		   ((status & rdy_mask) == rdy_mask)) {
1705		/* periodic trigger IRQ - during pen sense */
1706		at91_adc_touch_data_handler(indio);
1707	} else if (status & AT91_SAMA5D2_ISR_PENS) {
1708		/*
1709		 * touching, but the measurements are not ready yet.
1710		 * read and ignore.
1711		 */
1712		status = at91_adc_readl(st, XPOSR);
1713		status = at91_adc_readl(st, YPOSR);
1714		status = at91_adc_readl(st, PRESSR);
1715	} else if (iio_buffer_enabled(indio) &&
1716		   (status & AT91_SAMA5D2_IER_DRDY)) {
1717		/* triggered buffer without DMA */
1718		disable_irq_nosync(irq);
1719		iio_trigger_poll(indio->trig);
1720	} else if (iio_buffer_enabled(indio) && st->dma_st.dma_chan) {
1721		/* triggered buffer with DMA - should not happen */
1722		disable_irq_nosync(irq);
1723		WARN(true, "Unexpected irq occurred\n");
1724	} else if (!iio_buffer_enabled(indio)) {
1725		/* software requested conversion */
1726		st->conversion_value = at91_adc_read_chan(st, st->chan->address);
1727		st->conversion_done = true;
1728		wake_up_interruptible(&st->wq_data_available);
1729	}
1730	return IRQ_HANDLED;
1731}
1732
1733/* This needs to be called with direct mode claimed and st->lock locked. */
1734static int at91_adc_read_info_raw(struct iio_dev *indio_dev,
1735				  struct iio_chan_spec const *chan, int *val)
1736{
1737	struct at91_adc_state *st = iio_priv(indio_dev);
1738	u16 tmp_val;
1739	int ret;
1740
1741	ret = pm_runtime_resume_and_get(st->dev);
1742	if (ret < 0)
1743		return ret;
1744
1745	/*
1746	 * Keep in mind that we cannot use software trigger or touchscreen
1747	 * if external trigger is enabled
1748	 */
1749	if (chan->type == IIO_POSITIONRELATIVE) {
1750		ret = at91_adc_read_position(st, chan->channel,
1751					     &tmp_val);
1752		*val = tmp_val;
1753		if (ret > 0)
1754			ret = at91_adc_adjust_val_osr(st, val);
1755
1756		goto pm_runtime_put;
1757	}
1758	if (chan->type == IIO_PRESSURE) {
1759		ret = at91_adc_read_pressure(st, chan->channel,
1760					     &tmp_val);
1761		*val = tmp_val;
1762		if (ret > 0)
1763			ret = at91_adc_adjust_val_osr(st, val);
1764
1765		goto pm_runtime_put;
1766	}
1767
1768	/* in this case we have a voltage or temperature channel */
1769
1770	st->chan = chan;
1771
1772	at91_adc_cor(st, chan);
1773	at91_adc_writel(st, CHER, BIT(chan->channel));
1774	/*
1775	 * TEMPMR.TEMPON needs to update after CHER otherwise if none
1776	 * of the channels are enabled and TEMPMR.TEMPON = 1 will
1777	 * trigger DRDY interruption while preparing for temperature read.
1778	 */
1779	if (chan->type == IIO_TEMP)
1780		at91_adc_writel(st, TEMPMR, AT91_SAMA5D2_TEMPMR_TEMPON);
1781	at91_adc_eoc_ena(st, chan->channel);
1782	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_START);
1783
1784	ret = wait_event_interruptible_timeout(st->wq_data_available,
1785					       st->conversion_done,
1786					       msecs_to_jiffies(1000));
1787	if (ret == 0)
1788		ret = -ETIMEDOUT;
1789
1790	if (ret > 0) {
1791		*val = st->conversion_value;
1792		ret = at91_adc_adjust_val_osr(st, val);
1793		if (chan->scan_type.sign == 's')
1794			*val = sign_extend32(*val,
1795					     chan->scan_type.realbits - 1);
1796		st->conversion_done = false;
1797	}
1798
1799	at91_adc_eoc_dis(st, st->chan->channel);
1800	if (chan->type == IIO_TEMP)
1801		at91_adc_writel(st, TEMPMR, 0U);
1802	at91_adc_writel(st, CHDR, BIT(chan->channel));
1803
1804	/* Needed to ACK the DRDY interruption */
1805	at91_adc_readl(st, LCDR);
1806
1807pm_runtime_put:
1808	pm_runtime_mark_last_busy(st->dev);
1809	pm_runtime_put_autosuspend(st->dev);
1810	return ret;
1811}
1812
1813static int at91_adc_read_info_locked(struct iio_dev *indio_dev,
1814				     struct iio_chan_spec const *chan, int *val)
1815{
1816	struct at91_adc_state *st = iio_priv(indio_dev);
1817	int ret;
1818
1819	ret = iio_device_claim_direct_mode(indio_dev);
1820	if (ret)
1821		return ret;
1822
1823	mutex_lock(&st->lock);
1824	ret = at91_adc_read_info_raw(indio_dev, chan, val);
1825	mutex_unlock(&st->lock);
1826
1827	iio_device_release_direct_mode(indio_dev);
1828
1829	return ret;
1830}
1831
1832static void at91_adc_temp_sensor_configure(struct at91_adc_state *st,
1833					   bool start)
1834{
1835	u32 sample_rate, oversampling_ratio;
1836	u32 startup_time, tracktim, trackx;
1837
1838	if (start) {
1839		/*
1840		 * Configure the sensor for best accuracy: 10MHz frequency,
1841		 * oversampling rate of 256, tracktim=0xf and trackx=1.
1842		 */
1843		sample_rate = 10 * MEGA;
1844		oversampling_ratio = 256;
1845		startup_time = AT91_SAMA5D2_MR_STARTUP_TS_MIN;
1846		tracktim = AT91_SAMA5D2_MR_TRACKTIM_TS;
1847		trackx = AT91_SAMA5D2_TRACKX_TS;
1848
1849		st->temp_st.saved_sample_rate = st->current_sample_rate;
1850		st->temp_st.saved_oversampling = st->oversampling_ratio;
1851	} else {
1852		/* Go back to previous settings. */
1853		sample_rate = st->temp_st.saved_sample_rate;
1854		oversampling_ratio = st->temp_st.saved_oversampling;
1855		startup_time = st->soc_info.startup_time;
1856		tracktim = 0;
1857		trackx = 0;
1858	}
1859
1860	at91_adc_setup_samp_freq(st->indio_dev, sample_rate, startup_time,
1861				 tracktim);
1862	at91_adc_config_emr(st, oversampling_ratio, trackx);
1863}
1864
1865static int at91_adc_read_temp(struct iio_dev *indio_dev,
1866			      struct iio_chan_spec const *chan, int *val)
1867{
1868	struct at91_adc_state *st = iio_priv(indio_dev);
1869	struct at91_adc_temp_sensor_clb *clb = &st->soc_info.temp_sensor_clb;
1870	u64 div1, div2;
1871	u32 tmp;
1872	int ret, vbg, vtemp;
1873
1874	ret = iio_device_claim_direct_mode(indio_dev);
1875	if (ret)
1876		return ret;
1877	mutex_lock(&st->lock);
1878
1879	ret = pm_runtime_resume_and_get(st->dev);
1880	if (ret < 0)
1881		goto unlock;
1882
1883	at91_adc_temp_sensor_configure(st, true);
1884
1885	/* Read VBG. */
1886	tmp = at91_adc_readl(st, ACR);
1887	tmp |= AT91_SAMA5D2_ACR_SRCLCH;
1888	at91_adc_writel(st, ACR, tmp);
1889	ret = at91_adc_read_info_raw(indio_dev, chan, &vbg);
1890	if (ret < 0)
1891		goto restore_config;
1892
1893	/* Read VTEMP. */
1894	tmp &= ~AT91_SAMA5D2_ACR_SRCLCH;
1895	at91_adc_writel(st, ACR, tmp);
1896	ret = at91_adc_read_info_raw(indio_dev, chan, &vtemp);
1897
1898restore_config:
1899	/* Revert previous settings. */
1900	at91_adc_temp_sensor_configure(st, false);
1901	pm_runtime_mark_last_busy(st->dev);
1902	pm_runtime_put_autosuspend(st->dev);
1903unlock:
1904	mutex_unlock(&st->lock);
1905	iio_device_release_direct_mode(indio_dev);
1906	if (ret < 0)
1907		return ret;
1908
1909	/*
1910	 * Temp[milli] = p1[milli] + (vtemp * clb->p6 - clb->p4 * vbg)/
1911	 *			     (vbg * AT91_ADC_TS_VTEMP_DT)
1912	 */
1913	div1 = DIV_ROUND_CLOSEST_ULL(((u64)vtemp * clb->p6), vbg);
1914	div1 = DIV_ROUND_CLOSEST_ULL((div1 * 1000), AT91_ADC_TS_VTEMP_DT);
1915	div2 = DIV_ROUND_CLOSEST_ULL((u64)clb->p4, AT91_ADC_TS_VTEMP_DT);
1916	div2 *= 1000;
1917	*val = clb->p1 + (int)div1 - (int)div2;
1918
1919	return ret;
1920}
1921
1922static int at91_adc_read_raw(struct iio_dev *indio_dev,
1923			     struct iio_chan_spec const *chan,
1924			     int *val, int *val2, long mask)
1925{
1926	struct at91_adc_state *st = iio_priv(indio_dev);
1927
1928	switch (mask) {
1929	case IIO_CHAN_INFO_RAW:
1930		return at91_adc_read_info_locked(indio_dev, chan, val);
1931
1932	case IIO_CHAN_INFO_SCALE:
1933		*val = st->vref_uv / 1000;
1934		if (chan->differential)
1935			*val *= 2;
1936		*val2 = chan->scan_type.realbits;
1937		return IIO_VAL_FRACTIONAL_LOG2;
1938
1939	case IIO_CHAN_INFO_PROCESSED:
1940		if (chan->type != IIO_TEMP)
1941			return -EINVAL;
1942		return at91_adc_read_temp(indio_dev, chan, val);
1943
1944	case IIO_CHAN_INFO_SAMP_FREQ:
1945		*val = at91_adc_get_sample_freq(st);
1946		return IIO_VAL_INT;
1947
1948	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
1949		*val = st->oversampling_ratio;
1950		return IIO_VAL_INT;
1951
1952	default:
1953		return -EINVAL;
1954	}
1955}
1956
1957static int at91_adc_write_raw(struct iio_dev *indio_dev,
1958			      struct iio_chan_spec const *chan,
1959			      int val, int val2, long mask)
1960{
1961	struct at91_adc_state *st = iio_priv(indio_dev);
1962	int ret;
1963
1964	switch (mask) {
1965	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
1966		/* if no change, optimize out */
1967		if (val == st->oversampling_ratio)
1968			return 0;
1969
1970		ret = iio_device_claim_direct_mode(indio_dev);
1971		if (ret)
1972			return ret;
1973		mutex_lock(&st->lock);
1974		/* update ratio */
1975		ret = at91_adc_config_emr(st, val, 0);
1976		mutex_unlock(&st->lock);
1977		iio_device_release_direct_mode(indio_dev);
1978		return ret;
1979	case IIO_CHAN_INFO_SAMP_FREQ:
1980		if (val < st->soc_info.min_sample_rate ||
1981		    val > st->soc_info.max_sample_rate)
1982			return -EINVAL;
1983
1984		ret = iio_device_claim_direct_mode(indio_dev);
1985		if (ret)
1986			return ret;
1987		mutex_lock(&st->lock);
1988		at91_adc_setup_samp_freq(indio_dev, val,
1989					 st->soc_info.startup_time, 0);
1990		mutex_unlock(&st->lock);
1991		iio_device_release_direct_mode(indio_dev);
1992		return 0;
1993	default:
1994		return -EINVAL;
1995	}
1996}
1997
1998static int at91_adc_read_avail(struct iio_dev *indio_dev,
1999			       struct iio_chan_spec const *chan,
2000			       const int **vals, int *type, int *length,
2001			       long mask)
2002{
2003	struct at91_adc_state *st = iio_priv(indio_dev);
2004
2005	switch (mask) {
2006	case IIO_CHAN_INFO_OVERSAMPLING_RATIO:
2007		*vals = (int *)st->soc_info.platform->oversampling_avail;
2008		*type = IIO_VAL_INT;
2009		*length = st->soc_info.platform->oversampling_avail_no;
2010		return IIO_AVAIL_LIST;
2011	default:
2012		return -EINVAL;
2013	}
2014}
2015
2016static void at91_adc_dma_init(struct at91_adc_state *st)
2017{
2018	struct device *dev = &st->indio_dev->dev;
2019	struct dma_slave_config config = {0};
2020	/* we have 2 bytes for each channel */
2021	unsigned int sample_size = st->soc_info.platform->nr_channels * 2;
2022	/*
2023	 * We make the buffer double the size of the fifo,
2024	 * such that DMA uses one half of the buffer (full fifo size)
2025	 * and the software uses the other half to read/write.
2026	 */
2027	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
2028					  sample_size * 2, PAGE_SIZE);
2029
2030	if (st->dma_st.dma_chan)
2031		return;
2032
2033	st->dma_st.dma_chan = dma_request_chan(dev, "rx");
2034	if (IS_ERR(st->dma_st.dma_chan))  {
2035		dev_info(dev, "can't get DMA channel\n");
2036		st->dma_st.dma_chan = NULL;
2037		goto dma_exit;
2038	}
2039
2040	st->dma_st.rx_buf = dma_alloc_coherent(st->dma_st.dma_chan->device->dev,
2041					       pages * PAGE_SIZE,
2042					       &st->dma_st.rx_dma_buf,
2043					       GFP_KERNEL);
2044	if (!st->dma_st.rx_buf) {
2045		dev_info(dev, "can't allocate coherent DMA area\n");
2046		goto dma_chan_disable;
2047	}
2048
2049	/* Configure DMA channel to read data register */
2050	config.direction = DMA_DEV_TO_MEM;
2051	config.src_addr = (phys_addr_t)(st->dma_st.phys_addr
2052			  + st->soc_info.platform->layout->LCDR);
2053	config.src_addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
2054	config.src_maxburst = 1;
2055	config.dst_maxburst = 1;
2056
2057	if (dmaengine_slave_config(st->dma_st.dma_chan, &config)) {
2058		dev_info(dev, "can't configure DMA slave\n");
2059		goto dma_free_area;
2060	}
2061
2062	dev_info(dev, "using %s for rx DMA transfers\n",
2063		 dma_chan_name(st->dma_st.dma_chan));
2064
2065	return;
2066
2067dma_free_area:
2068	dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE,
2069			  st->dma_st.rx_buf, st->dma_st.rx_dma_buf);
2070dma_chan_disable:
2071	dma_release_channel(st->dma_st.dma_chan);
2072	st->dma_st.dma_chan = NULL;
2073dma_exit:
2074	dev_info(dev, "continuing without DMA support\n");
2075}
2076
2077static void at91_adc_dma_disable(struct at91_adc_state *st)
2078{
2079	struct device *dev = &st->indio_dev->dev;
2080	/* we have 2 bytes for each channel */
2081	unsigned int sample_size = st->soc_info.platform->nr_channels * 2;
2082	unsigned int pages = DIV_ROUND_UP(AT91_HWFIFO_MAX_SIZE *
2083					  sample_size * 2, PAGE_SIZE);
2084
2085	/* if we are not using DMA, just return */
2086	if (!st->dma_st.dma_chan)
2087		return;
2088
2089	/* wait for all transactions to be terminated first*/
2090	dmaengine_terminate_sync(st->dma_st.dma_chan);
2091
2092	dma_free_coherent(st->dma_st.dma_chan->device->dev, pages * PAGE_SIZE,
2093			  st->dma_st.rx_buf, st->dma_st.rx_dma_buf);
2094	dma_release_channel(st->dma_st.dma_chan);
2095	st->dma_st.dma_chan = NULL;
2096
2097	dev_info(dev, "continuing without DMA support\n");
2098}
2099
2100static int at91_adc_set_watermark(struct iio_dev *indio_dev, unsigned int val)
2101{
2102	struct at91_adc_state *st = iio_priv(indio_dev);
2103	int ret;
2104
2105	if (val > AT91_HWFIFO_MAX_SIZE)
2106		val = AT91_HWFIFO_MAX_SIZE;
2107
2108	if (!st->selected_trig->hw_trig) {
2109		dev_dbg(&indio_dev->dev, "we need hw trigger for DMA\n");
2110		return 0;
2111	}
2112
2113	dev_dbg(&indio_dev->dev, "new watermark is %u\n", val);
2114	st->dma_st.watermark = val;
2115
2116	/*
2117	 * The logic here is: if we have watermark 1, it means we do
2118	 * each conversion with it's own IRQ, thus we don't need DMA.
2119	 * If the watermark is higher, we do DMA to do all the transfers in bulk
2120	 */
2121
2122	if (val == 1)
2123		at91_adc_dma_disable(st);
2124	else if (val > 1)
2125		at91_adc_dma_init(st);
2126
2127	/*
2128	 * We can start the DMA only after setting the watermark and
2129	 * having the DMA initialization completed
2130	 */
2131	ret = at91_adc_buffer_prepare(indio_dev);
2132	if (ret)
2133		at91_adc_dma_disable(st);
2134
2135	return ret;
2136}
2137
2138static int at91_adc_update_scan_mode(struct iio_dev *indio_dev,
2139				     const unsigned long *scan_mask)
2140{
2141	struct at91_adc_state *st = iio_priv(indio_dev);
2142
2143	if (bitmap_subset(scan_mask, &st->touch_st.channels_bitmask,
2144			  st->soc_info.platform->max_index + 1))
2145		return 0;
2146	/*
2147	 * if the new bitmap is a combination of touchscreen and regular
2148	 * channels, then we are not fine
2149	 */
2150	if (bitmap_intersects(&st->touch_st.channels_bitmask, scan_mask,
2151			      st->soc_info.platform->max_index + 1))
2152		return -EINVAL;
2153	return 0;
2154}
2155
2156static void at91_adc_hw_init(struct iio_dev *indio_dev)
2157{
2158	struct at91_adc_state *st = iio_priv(indio_dev);
2159
2160	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST);
2161	if (st->soc_info.platform->layout->EOC_IDR)
2162		at91_adc_writel(st, EOC_IDR, 0xffffffff);
2163	at91_adc_writel(st, IDR, 0xffffffff);
2164	/*
2165	 * Transfer field must be set to 2 according to the datasheet and
2166	 * allows different analog settings for each channel.
2167	 */
2168	at91_adc_writel(st, MR,
2169			AT91_SAMA5D2_MR_TRANSFER(2) | AT91_SAMA5D2_MR_ANACH);
2170
2171	at91_adc_setup_samp_freq(indio_dev, st->soc_info.min_sample_rate,
2172				 st->soc_info.startup_time, 0);
2173
2174	/* configure extended mode register */
2175	at91_adc_config_emr(st, st->oversampling_ratio, 0);
2176}
2177
2178static ssize_t at91_adc_get_fifo_state(struct device *dev,
2179				       struct device_attribute *attr, char *buf)
2180{
2181	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
2182	struct at91_adc_state *st = iio_priv(indio_dev);
2183
2184	return sysfs_emit(buf, "%d\n", !!st->dma_st.dma_chan);
2185}
2186
2187static ssize_t at91_adc_get_watermark(struct device *dev,
2188				      struct device_attribute *attr, char *buf)
2189{
2190	struct iio_dev *indio_dev = dev_to_iio_dev(dev);
2191	struct at91_adc_state *st = iio_priv(indio_dev);
2192
2193	return sysfs_emit(buf, "%d\n", st->dma_st.watermark);
2194}
2195
2196static IIO_DEVICE_ATTR(hwfifo_enabled, 0444,
2197		       at91_adc_get_fifo_state, NULL, 0);
2198static IIO_DEVICE_ATTR(hwfifo_watermark, 0444,
2199		       at91_adc_get_watermark, NULL, 0);
2200
2201IIO_STATIC_CONST_DEVICE_ATTR(hwfifo_watermark_min, "2");
2202IIO_STATIC_CONST_DEVICE_ATTR(hwfifo_watermark_max, AT91_HWFIFO_MAX_SIZE_STR);
2203
2204static const struct iio_dev_attr *at91_adc_fifo_attributes[] = {
2205	&iio_dev_attr_hwfifo_watermark_min,
2206	&iio_dev_attr_hwfifo_watermark_max,
2207	&iio_dev_attr_hwfifo_watermark,
2208	&iio_dev_attr_hwfifo_enabled,
2209	NULL,
2210};
2211
2212static const struct iio_info at91_adc_info = {
2213	.read_avail = &at91_adc_read_avail,
2214	.read_raw = &at91_adc_read_raw,
2215	.write_raw = &at91_adc_write_raw,
2216	.update_scan_mode = &at91_adc_update_scan_mode,
2217	.fwnode_xlate = &at91_adc_fwnode_xlate,
2218	.hwfifo_set_watermark = &at91_adc_set_watermark,
2219};
2220
2221static int at91_adc_buffer_and_trigger_init(struct device *dev,
2222					    struct iio_dev *indio)
2223{
2224	struct at91_adc_state *st = iio_priv(indio);
2225	const struct iio_dev_attr **fifo_attrs;
2226	int ret;
2227
2228	if (st->selected_trig->hw_trig)
2229		fifo_attrs = at91_adc_fifo_attributes;
2230	else
2231		fifo_attrs = NULL;
2232
2233	ret = devm_iio_triggered_buffer_setup_ext(&indio->dev, indio,
2234		&iio_pollfunc_store_time, &at91_adc_trigger_handler,
2235		IIO_BUFFER_DIRECTION_IN, &at91_buffer_setup_ops, fifo_attrs);
2236	if (ret < 0) {
2237		dev_err(dev, "couldn't initialize the buffer.\n");
2238		return ret;
2239	}
2240
2241	if (!st->selected_trig->hw_trig)
2242		return 0;
2243
2244	st->trig = at91_adc_allocate_trigger(indio, st->selected_trig->name);
2245	if (IS_ERR(st->trig)) {
2246		dev_err(dev, "could not allocate trigger\n");
2247		return PTR_ERR(st->trig);
2248	}
2249
2250	/*
2251	 * Initially the iio buffer has a length of 2 and
2252	 * a watermark of 1
2253	 */
2254	st->dma_st.watermark = 1;
2255
2256	return 0;
2257}
2258
2259static int at91_adc_temp_sensor_init(struct at91_adc_state *st,
2260				     struct device *dev)
2261{
2262	struct at91_adc_temp_sensor_clb *clb = &st->soc_info.temp_sensor_clb;
2263	struct nvmem_cell *temp_calib;
2264	u32 *buf;
2265	size_t len;
2266	int ret = 0;
2267
2268	if (!st->soc_info.platform->temp_sensor)
2269		return 0;
2270
2271	/* Get the calibration data from NVMEM. */
2272	temp_calib = devm_nvmem_cell_get(dev, "temperature_calib");
2273	if (IS_ERR(temp_calib)) {
2274		ret = PTR_ERR(temp_calib);
2275		if (ret != -ENOENT)
2276			dev_err(dev, "Failed to get temperature_calib cell!\n");
2277		return ret;
2278	}
2279
2280	buf = nvmem_cell_read(temp_calib, &len);
2281	if (IS_ERR(buf)) {
2282		dev_err(dev, "Failed to read calibration data!\n");
2283		return PTR_ERR(buf);
2284	}
2285	if (len < AT91_ADC_TS_CLB_IDX_MAX * 4) {
2286		dev_err(dev, "Invalid calibration data!\n");
2287		ret = -EINVAL;
2288		goto free_buf;
2289	}
2290
2291	/* Store calibration data for later use. */
2292	clb->p1 = buf[AT91_ADC_TS_CLB_IDX_P1];
2293	clb->p4 = buf[AT91_ADC_TS_CLB_IDX_P4];
2294	clb->p6 = buf[AT91_ADC_TS_CLB_IDX_P6];
2295
2296	/*
2297	 * We prepare here the conversion to milli to avoid doing it on hotpath.
2298	 */
2299	clb->p1 = clb->p1 * 1000;
2300
2301free_buf:
2302	kfree(buf);
2303	return ret;
2304}
2305
2306static int at91_adc_probe(struct platform_device *pdev)
2307{
2308	struct device *dev = &pdev->dev;
2309	struct iio_dev *indio_dev;
2310	struct at91_adc_state *st;
2311	struct resource	*res;
2312	int ret, i, num_channels;
2313	u32 edge_type = IRQ_TYPE_NONE;
2314
2315	indio_dev = devm_iio_device_alloc(&pdev->dev, sizeof(*st));
2316	if (!indio_dev)
2317		return -ENOMEM;
2318
2319	st = iio_priv(indio_dev);
2320	st->indio_dev = indio_dev;
2321
2322	st->soc_info.platform = device_get_match_data(dev);
2323
2324	ret = at91_adc_temp_sensor_init(st, &pdev->dev);
2325	/* Don't register temperature channel if initialization failed. */
2326	if (ret)
2327		num_channels = st->soc_info.platform->max_channels - 1;
2328	else
2329		num_channels = st->soc_info.platform->max_channels;
2330
2331	indio_dev->name = dev_name(&pdev->dev);
2332	indio_dev->modes = INDIO_DIRECT_MODE | INDIO_BUFFER_SOFTWARE;
2333	indio_dev->info = &at91_adc_info;
2334	indio_dev->channels = *st->soc_info.platform->adc_channels;
2335	indio_dev->num_channels = num_channels;
2336
2337	bitmap_set(&st->touch_st.channels_bitmask,
2338		   st->soc_info.platform->touch_chan_x, 1);
2339	bitmap_set(&st->touch_st.channels_bitmask,
2340		   st->soc_info.platform->touch_chan_y, 1);
2341	bitmap_set(&st->touch_st.channels_bitmask,
2342		   st->soc_info.platform->touch_chan_p, 1);
2343
2344	st->oversampling_ratio = 1;
2345
2346	ret = device_property_read_u32(dev, "atmel,min-sample-rate-hz",
2347				       &st->soc_info.min_sample_rate);
2348	if (ret) {
2349		dev_err(&pdev->dev,
2350			"invalid or missing value for atmel,min-sample-rate-hz\n");
2351		return ret;
2352	}
2353
2354	ret = device_property_read_u32(dev, "atmel,max-sample-rate-hz",
2355				       &st->soc_info.max_sample_rate);
2356	if (ret) {
2357		dev_err(&pdev->dev,
2358			"invalid or missing value for atmel,max-sample-rate-hz\n");
2359		return ret;
2360	}
2361
2362	ret = device_property_read_u32(dev, "atmel,startup-time-ms",
2363				       &st->soc_info.startup_time);
2364	if (ret) {
2365		dev_err(&pdev->dev,
2366			"invalid or missing value for atmel,startup-time-ms\n");
2367		return ret;
2368	}
2369
2370	ret = device_property_read_u32(dev, "atmel,trigger-edge-type",
2371				       &edge_type);
2372	if (ret) {
2373		dev_dbg(&pdev->dev,
2374			"atmel,trigger-edge-type not specified, only software trigger available\n");
2375	}
2376
2377	st->selected_trig = NULL;
2378
2379	/* find the right trigger, or no trigger at all */
2380	for (i = 0; i < st->soc_info.platform->hw_trig_cnt + 1; i++)
2381		if (at91_adc_trigger_list[i].edge_type == edge_type) {
2382			st->selected_trig = &at91_adc_trigger_list[i];
2383			break;
2384		}
2385
2386	if (!st->selected_trig) {
2387		dev_err(&pdev->dev, "invalid external trigger edge value\n");
2388		return -EINVAL;
2389	}
2390
2391	init_waitqueue_head(&st->wq_data_available);
2392	mutex_init(&st->lock);
2393	INIT_WORK(&st->touch_st.workq, at91_adc_workq_handler);
2394
2395	st->base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
2396	if (IS_ERR(st->base))
2397		return PTR_ERR(st->base);
2398
2399	/* if we plan to use DMA, we need the physical address of the regs */
2400	st->dma_st.phys_addr = res->start;
2401
2402	st->irq = platform_get_irq(pdev, 0);
2403	if (st->irq < 0)
2404		return st->irq;
2405
2406	st->per_clk = devm_clk_get(&pdev->dev, "adc_clk");
2407	if (IS_ERR(st->per_clk))
2408		return PTR_ERR(st->per_clk);
2409
2410	st->reg = devm_regulator_get(&pdev->dev, "vddana");
2411	if (IS_ERR(st->reg))
2412		return PTR_ERR(st->reg);
2413
2414	st->vref = devm_regulator_get(&pdev->dev, "vref");
2415	if (IS_ERR(st->vref))
2416		return PTR_ERR(st->vref);
2417
2418	ret = devm_request_irq(&pdev->dev, st->irq, at91_adc_interrupt, 0,
2419			       pdev->dev.driver->name, indio_dev);
2420	if (ret)
2421		return ret;
2422
2423	ret = regulator_enable(st->reg);
2424	if (ret)
2425		return ret;
2426
2427	ret = regulator_enable(st->vref);
2428	if (ret)
2429		goto reg_disable;
2430
2431	st->vref_uv = regulator_get_voltage(st->vref);
2432	if (st->vref_uv <= 0) {
2433		ret = -EINVAL;
2434		goto vref_disable;
2435	}
2436
2437	ret = clk_prepare_enable(st->per_clk);
2438	if (ret)
2439		goto vref_disable;
2440
2441	platform_set_drvdata(pdev, indio_dev);
2442	st->dev = &pdev->dev;
2443	pm_runtime_set_autosuspend_delay(st->dev, 500);
2444	pm_runtime_use_autosuspend(st->dev);
2445	pm_runtime_set_active(st->dev);
2446	pm_runtime_enable(st->dev);
2447	pm_runtime_get_noresume(st->dev);
2448
2449	at91_adc_hw_init(indio_dev);
2450
2451	ret = at91_adc_buffer_and_trigger_init(&pdev->dev, indio_dev);
2452	if (ret < 0)
2453		goto err_pm_disable;
2454
2455	if (dma_coerce_mask_and_coherent(&indio_dev->dev, DMA_BIT_MASK(32)))
2456		dev_info(&pdev->dev, "cannot set DMA mask to 32-bit\n");
2457
2458	ret = iio_device_register(indio_dev);
2459	if (ret < 0)
2460		goto dma_disable;
2461
2462	if (st->selected_trig->hw_trig)
2463		dev_info(&pdev->dev, "setting up trigger as %s\n",
2464			 st->selected_trig->name);
2465
2466	dev_info(&pdev->dev, "version: %x\n",
2467		 readl_relaxed(st->base + st->soc_info.platform->layout->VERSION));
2468
2469	pm_runtime_mark_last_busy(st->dev);
2470	pm_runtime_put_autosuspend(st->dev);
2471
2472	return 0;
2473
2474dma_disable:
2475	at91_adc_dma_disable(st);
2476err_pm_disable:
2477	pm_runtime_put_noidle(st->dev);
2478	pm_runtime_disable(st->dev);
2479	pm_runtime_set_suspended(st->dev);
2480	pm_runtime_dont_use_autosuspend(st->dev);
2481	clk_disable_unprepare(st->per_clk);
2482vref_disable:
2483	regulator_disable(st->vref);
2484reg_disable:
2485	regulator_disable(st->reg);
2486	return ret;
2487}
2488
2489static void at91_adc_remove(struct platform_device *pdev)
2490{
2491	struct iio_dev *indio_dev = platform_get_drvdata(pdev);
2492	struct at91_adc_state *st = iio_priv(indio_dev);
2493
2494	iio_device_unregister(indio_dev);
2495
2496	at91_adc_dma_disable(st);
2497
2498	pm_runtime_disable(st->dev);
2499	pm_runtime_set_suspended(st->dev);
2500	clk_disable_unprepare(st->per_clk);
2501
2502	regulator_disable(st->vref);
2503	regulator_disable(st->reg);
2504}
2505
2506static int at91_adc_suspend(struct device *dev)
2507{
2508	struct iio_dev *indio_dev = dev_get_drvdata(dev);
2509	struct at91_adc_state *st = iio_priv(indio_dev);
2510	int ret;
2511
2512	ret = pm_runtime_resume_and_get(st->dev);
2513	if (ret < 0)
2514		return ret;
2515
2516	if (iio_buffer_enabled(indio_dev))
2517		at91_adc_buffer_postdisable(indio_dev);
2518
2519	/*
2520	 * Do a sofware reset of the ADC before we go to suspend.
2521	 * this will ensure that all pins are free from being muxed by the ADC
2522	 * and can be used by for other devices.
2523	 * Otherwise, ADC will hog them and we can't go to suspend mode.
2524	 */
2525	at91_adc_writel(st, CR, AT91_SAMA5D2_CR_SWRST);
2526
2527	pm_runtime_mark_last_busy(st->dev);
2528	pm_runtime_put_noidle(st->dev);
2529	clk_disable_unprepare(st->per_clk);
2530	regulator_disable(st->vref);
2531	regulator_disable(st->reg);
2532
2533	return pinctrl_pm_select_sleep_state(dev);
2534}
2535
2536static int at91_adc_resume(struct device *dev)
2537{
2538	struct iio_dev *indio_dev = dev_get_drvdata(dev);
2539	struct at91_adc_state *st = iio_priv(indio_dev);
2540	int ret;
2541
2542	ret = pinctrl_pm_select_default_state(dev);
2543	if (ret)
2544		goto resume_failed;
2545
2546	ret = regulator_enable(st->reg);
2547	if (ret)
2548		goto resume_failed;
2549
2550	ret = regulator_enable(st->vref);
2551	if (ret)
2552		goto reg_disable_resume;
2553
2554	ret = clk_prepare_enable(st->per_clk);
2555	if (ret)
2556		goto vref_disable_resume;
2557
2558	pm_runtime_get_noresume(st->dev);
2559
2560	at91_adc_hw_init(indio_dev);
2561
2562	/* reconfiguring trigger hardware state */
2563	if (iio_buffer_enabled(indio_dev)) {
2564		ret = at91_adc_buffer_prepare(indio_dev);
2565		if (ret)
2566			goto pm_runtime_put;
2567
2568		at91_adc_configure_trigger_registers(st, true);
2569	}
2570
2571	pm_runtime_mark_last_busy(st->dev);
2572	pm_runtime_put_autosuspend(st->dev);
2573
2574	return 0;
2575
2576pm_runtime_put:
2577	pm_runtime_mark_last_busy(st->dev);
2578	pm_runtime_put_noidle(st->dev);
2579	clk_disable_unprepare(st->per_clk);
2580vref_disable_resume:
2581	regulator_disable(st->vref);
2582reg_disable_resume:
2583	regulator_disable(st->reg);
2584resume_failed:
2585	dev_err(&indio_dev->dev, "failed to resume\n");
2586	return ret;
2587}
2588
2589static int at91_adc_runtime_suspend(struct device *dev)
2590{
2591	struct iio_dev *indio_dev = dev_get_drvdata(dev);
2592	struct at91_adc_state *st = iio_priv(indio_dev);
2593
2594	clk_disable(st->per_clk);
2595
2596	return 0;
2597}
2598
2599static int at91_adc_runtime_resume(struct device *dev)
2600{
2601	struct iio_dev *indio_dev = dev_get_drvdata(dev);
2602	struct at91_adc_state *st = iio_priv(indio_dev);
2603
2604	return clk_enable(st->per_clk);
2605}
2606
2607static const struct dev_pm_ops at91_adc_pm_ops = {
2608	SYSTEM_SLEEP_PM_OPS(at91_adc_suspend, at91_adc_resume)
2609	RUNTIME_PM_OPS(at91_adc_runtime_suspend, at91_adc_runtime_resume,
2610		       NULL)
2611};
2612
2613static const struct of_device_id at91_adc_dt_match[] = {
2614	{
2615		.compatible = "atmel,sama5d2-adc",
2616		.data = (const void *)&sama5d2_platform,
2617	}, {
2618		.compatible = "microchip,sama7g5-adc",
2619		.data = (const void *)&sama7g5_platform,
2620	}, {
2621		/* sentinel */
2622	}
2623};
2624MODULE_DEVICE_TABLE(of, at91_adc_dt_match);
2625
2626static struct platform_driver at91_adc_driver = {
2627	.probe = at91_adc_probe,
2628	.remove_new = at91_adc_remove,
2629	.driver = {
2630		.name = "at91-sama5d2_adc",
2631		.of_match_table = at91_adc_dt_match,
2632		.pm = pm_ptr(&at91_adc_pm_ops),
2633	},
2634};
2635module_platform_driver(at91_adc_driver)
2636
2637MODULE_AUTHOR("Ludovic Desroches <ludovic.desroches@microchip.com>");
2638MODULE_AUTHOR("Eugen Hristev <eugen.hristev@microchip.com");
2639MODULE_DESCRIPTION("Atmel AT91 SAMA5D2 ADC");
2640MODULE_LICENSE("GPL v2");
2641