1// SPDX-License-Identifier: GPL-2.0-only
2/*
3* Copyright (C) 2015 Broadcom Corporation
4*
5*/
6#include <linux/module.h>
7#include <linux/init.h>
8#include <linux/input.h>
9#include <linux/delay.h>
10#include <linux/interrupt.h>
11#include <linux/keyboard.h>
12#include <linux/platform_device.h>
13#include <linux/slab.h>
14#include <linux/of.h>
15#include <asm/irq.h>
16#include <linux/io.h>
17#include <linux/clk.h>
18#include <linux/serio.h>
19#include <linux/mfd/syscon.h>
20#include <linux/regmap.h>
21
22#define IPROC_TS_NAME "iproc-ts"
23
24#define PEN_DOWN_STATUS     1
25#define PEN_UP_STATUS       0
26
27#define X_MIN               0
28#define Y_MIN               0
29#define X_MAX               0xFFF
30#define Y_MAX               0xFFF
31
32/* Value given by controller for invalid coordinate. */
33#define INVALID_COORD       0xFFFFFFFF
34
35/* Register offsets */
36#define REGCTL1             0x00
37#define REGCTL2             0x04
38#define INTERRUPT_THRES     0x08
39#define INTERRUPT_MASK      0x0c
40
41#define INTERRUPT_STATUS    0x10
42#define CONTROLLER_STATUS   0x14
43#define FIFO_DATA           0x18
44#define FIFO_DATA_X_Y_MASK  0xFFFF
45#define ANALOG_CONTROL      0x1c
46
47#define AUX_DATA            0x20
48#define DEBOUNCE_CNTR_STAT  0x24
49#define SCAN_CNTR_STAT      0x28
50#define REM_CNTR_STAT       0x2c
51
52#define SETTLING_TIMER_STAT 0x30
53#define SPARE_REG           0x34
54#define SOFT_BYPASS_CONTROL 0x38
55#define SOFT_BYPASS_DATA    0x3c
56
57
58/* Bit values for INTERRUPT_MASK and INTERRUPT_STATUS regs */
59#define TS_PEN_INTR_MASK        BIT(0)
60#define TS_FIFO_INTR_MASK       BIT(2)
61
62/* Bit values for CONTROLLER_STATUS reg1 */
63#define TS_PEN_DOWN             BIT(0)
64
65/* Shift values for control reg1 */
66#define SCANNING_PERIOD_SHIFT   24
67#define DEBOUNCE_TIMEOUT_SHIFT  16
68#define SETTLING_TIMEOUT_SHIFT  8
69#define TOUCH_TIMEOUT_SHIFT     0
70
71/* Shift values for coordinates from fifo */
72#define X_COORD_SHIFT  0
73#define Y_COORD_SHIFT  16
74
75/* Bit values for REGCTL2 */
76#define TS_CONTROLLER_EN_BIT    BIT(16)
77#define TS_CONTROLLER_AVGDATA_SHIFT 8
78#define TS_CONTROLLER_AVGDATA_MASK (0x7 << TS_CONTROLLER_AVGDATA_SHIFT)
79#define TS_CONTROLLER_PWR_LDO   BIT(5)
80#define TS_CONTROLLER_PWR_ADC   BIT(4)
81#define TS_CONTROLLER_PWR_BGP   BIT(3)
82#define TS_CONTROLLER_PWR_TS    BIT(2)
83#define TS_WIRE_MODE_BIT        BIT(1)
84
85#define dbg_reg(dev, priv, reg) \
86do { \
87	u32 val; \
88	regmap_read(priv->regmap, reg, &val); \
89	dev_dbg(dev, "%20s= 0x%08x\n", #reg, val); \
90} while (0)
91
92struct tsc_param {
93	/* Each step is 1024 us.  Valid 1-256 */
94	u32 scanning_period;
95
96	/*  Each step is 512 us.  Valid 0-255 */
97	u32 debounce_timeout;
98
99	/*
100	 * The settling duration (in ms) is the amount of time the tsc
101	 * waits to allow the voltage to settle after turning on the
102	 * drivers in detection mode. Valid values: 0-11
103	 *   0 =  0.008 ms
104	 *   1 =  0.01 ms
105	 *   2 =  0.02 ms
106	 *   3 =  0.04 ms
107	 *   4 =  0.08 ms
108	 *   5 =  0.16 ms
109	 *   6 =  0.32 ms
110	 *   7 =  0.64 ms
111	 *   8 =  1.28 ms
112	 *   9 =  2.56 ms
113	 *   10 = 5.12 ms
114	 *   11 = 10.24 ms
115	 */
116	u32 settling_timeout;
117
118	/* touch timeout in sample counts */
119	u32 touch_timeout;
120
121	/*
122	 * Number of data samples which are averaged before a final data point
123	 * is placed into the FIFO
124	 */
125	u32 average_data;
126
127	/* FIFO threshold */
128	u32 fifo_threshold;
129
130	/* Optional standard touchscreen properties. */
131	u32 max_x;
132	u32 max_y;
133	u32 fuzz_x;
134	u32 fuzz_y;
135	bool invert_x;
136	bool invert_y;
137};
138
139struct iproc_ts_priv {
140	struct platform_device *pdev;
141	struct input_dev *idev;
142
143	struct regmap *regmap;
144	struct clk *tsc_clk;
145
146	int  pen_status;
147	struct tsc_param cfg_params;
148};
149
150/*
151 * Set default values the same as hardware reset values
152 * except for fifo_threshold with is set to 1.
153 */
154static const struct tsc_param iproc_default_config = {
155	.scanning_period  = 0x5,  /* 1 to 256 */
156	.debounce_timeout = 0x28, /* 0 to 255 */
157	.settling_timeout = 0x7,  /* 0 to 11 */
158	.touch_timeout    = 0xa,  /* 0 to 255 */
159	.average_data     = 5,    /* entry 5 = 32 pts */
160	.fifo_threshold   = 1,    /* 0 to 31 */
161	.max_x            = X_MAX,
162	.max_y            = Y_MAX,
163};
164
165static void ts_reg_dump(struct iproc_ts_priv *priv)
166{
167	struct device *dev = &priv->pdev->dev;
168
169	dbg_reg(dev, priv, REGCTL1);
170	dbg_reg(dev, priv, REGCTL2);
171	dbg_reg(dev, priv, INTERRUPT_THRES);
172	dbg_reg(dev, priv, INTERRUPT_MASK);
173	dbg_reg(dev, priv, INTERRUPT_STATUS);
174	dbg_reg(dev, priv, CONTROLLER_STATUS);
175	dbg_reg(dev, priv, FIFO_DATA);
176	dbg_reg(dev, priv, ANALOG_CONTROL);
177	dbg_reg(dev, priv, AUX_DATA);
178	dbg_reg(dev, priv, DEBOUNCE_CNTR_STAT);
179	dbg_reg(dev, priv, SCAN_CNTR_STAT);
180	dbg_reg(dev, priv, REM_CNTR_STAT);
181	dbg_reg(dev, priv, SETTLING_TIMER_STAT);
182	dbg_reg(dev, priv, SPARE_REG);
183	dbg_reg(dev, priv, SOFT_BYPASS_CONTROL);
184	dbg_reg(dev, priv, SOFT_BYPASS_DATA);
185}
186
187static irqreturn_t iproc_touchscreen_interrupt(int irq, void *data)
188{
189	struct platform_device *pdev = data;
190	struct iproc_ts_priv *priv = platform_get_drvdata(pdev);
191	u32 intr_status;
192	u32 raw_coordinate;
193	u16 x;
194	u16 y;
195	int i;
196	bool needs_sync = false;
197
198	regmap_read(priv->regmap, INTERRUPT_STATUS, &intr_status);
199	intr_status &= TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
200	if (intr_status == 0)
201		return IRQ_NONE;
202
203	/* Clear all interrupt status bits, write-1-clear */
204	regmap_write(priv->regmap, INTERRUPT_STATUS, intr_status);
205	/* Pen up/down */
206	if (intr_status & TS_PEN_INTR_MASK) {
207		regmap_read(priv->regmap, CONTROLLER_STATUS, &priv->pen_status);
208		if (priv->pen_status & TS_PEN_DOWN)
209			priv->pen_status = PEN_DOWN_STATUS;
210		else
211			priv->pen_status = PEN_UP_STATUS;
212
213		input_report_key(priv->idev, BTN_TOUCH,	priv->pen_status);
214		needs_sync = true;
215
216		dev_dbg(&priv->pdev->dev,
217			"pen up-down (%d)\n", priv->pen_status);
218	}
219
220	/* coordinates in FIFO exceed the theshold */
221	if (intr_status & TS_FIFO_INTR_MASK) {
222		for (i = 0; i < priv->cfg_params.fifo_threshold; i++) {
223			regmap_read(priv->regmap, FIFO_DATA, &raw_coordinate);
224			if (raw_coordinate == INVALID_COORD)
225				continue;
226
227			/*
228			 * The x and y coordinate are 16 bits each
229			 * with the x in the lower 16 bits and y in the
230			 * upper 16 bits.
231			 */
232			x = (raw_coordinate >> X_COORD_SHIFT) &
233				FIFO_DATA_X_Y_MASK;
234			y = (raw_coordinate >> Y_COORD_SHIFT) &
235				FIFO_DATA_X_Y_MASK;
236
237			/* We only want to retain the 12 msb of the 16 */
238			x = (x >> 4) & 0x0FFF;
239			y = (y >> 4) & 0x0FFF;
240
241			/* Adjust x y according to LCD tsc mount angle. */
242			if (priv->cfg_params.invert_x)
243				x = priv->cfg_params.max_x - x;
244
245			if (priv->cfg_params.invert_y)
246				y = priv->cfg_params.max_y - y;
247
248			input_report_abs(priv->idev, ABS_X, x);
249			input_report_abs(priv->idev, ABS_Y, y);
250			needs_sync = true;
251
252			dev_dbg(&priv->pdev->dev, "xy (0x%x 0x%x)\n", x, y);
253		}
254	}
255
256	if (needs_sync)
257		input_sync(priv->idev);
258
259	return IRQ_HANDLED;
260}
261
262static int iproc_ts_start(struct input_dev *idev)
263{
264	u32 val;
265	u32 mask;
266	int error;
267	struct iproc_ts_priv *priv = input_get_drvdata(idev);
268
269	/* Enable clock */
270	error = clk_prepare_enable(priv->tsc_clk);
271	if (error) {
272		dev_err(&priv->pdev->dev, "%s clk_prepare_enable failed %d\n",
273			__func__, error);
274		return error;
275	}
276
277	/*
278	 * Interrupt is generated when:
279	 *  FIFO reaches the int_th value, and pen event(up/down)
280	 */
281	val = TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
282	regmap_update_bits(priv->regmap, INTERRUPT_MASK, val, val);
283
284	val = priv->cfg_params.fifo_threshold;
285	regmap_write(priv->regmap, INTERRUPT_THRES, val);
286
287	/* Initialize control reg1 */
288	val = 0;
289	val |= priv->cfg_params.scanning_period << SCANNING_PERIOD_SHIFT;
290	val |= priv->cfg_params.debounce_timeout << DEBOUNCE_TIMEOUT_SHIFT;
291	val |= priv->cfg_params.settling_timeout << SETTLING_TIMEOUT_SHIFT;
292	val |= priv->cfg_params.touch_timeout << TOUCH_TIMEOUT_SHIFT;
293	regmap_write(priv->regmap, REGCTL1, val);
294
295	/* Try to clear all interrupt status */
296	val = TS_FIFO_INTR_MASK | TS_PEN_INTR_MASK;
297	regmap_update_bits(priv->regmap, INTERRUPT_STATUS, val, val);
298
299	/* Initialize control reg2 */
300	val = TS_CONTROLLER_EN_BIT | TS_WIRE_MODE_BIT;
301	val |= priv->cfg_params.average_data << TS_CONTROLLER_AVGDATA_SHIFT;
302
303	mask = (TS_CONTROLLER_AVGDATA_MASK);
304	mask |= (TS_CONTROLLER_PWR_LDO |	/* PWR up LDO */
305		   TS_CONTROLLER_PWR_ADC |	/* PWR up ADC */
306		   TS_CONTROLLER_PWR_BGP |	/* PWR up BGP */
307		   TS_CONTROLLER_PWR_TS);	/* PWR up TS */
308	mask |= val;
309	regmap_update_bits(priv->regmap, REGCTL2, mask, val);
310
311	ts_reg_dump(priv);
312
313	return 0;
314}
315
316static void iproc_ts_stop(struct input_dev *dev)
317{
318	u32 val;
319	struct iproc_ts_priv *priv = input_get_drvdata(dev);
320
321	/*
322	 * Disable FIFO int_th and pen event(up/down)Interrupts only
323	 * as the interrupt mask register is shared between ADC, TS and
324	 * flextimer.
325	 */
326	val = TS_PEN_INTR_MASK | TS_FIFO_INTR_MASK;
327	regmap_update_bits(priv->regmap, INTERRUPT_MASK, val, 0);
328
329	/* Only power down touch screen controller */
330	val = TS_CONTROLLER_PWR_TS;
331	regmap_update_bits(priv->regmap, REGCTL2, val, val);
332
333	clk_disable(priv->tsc_clk);
334}
335
336static int iproc_get_tsc_config(struct device *dev, struct iproc_ts_priv *priv)
337{
338	struct device_node *np = dev->of_node;
339	u32 val;
340
341	priv->cfg_params = iproc_default_config;
342
343	if (!np)
344		return 0;
345
346	if (of_property_read_u32(np, "scanning_period", &val) >= 0) {
347		if (val < 1 || val > 256) {
348			dev_err(dev, "scanning_period (%u) must be [1-256]\n",
349				val);
350			return -EINVAL;
351		}
352		priv->cfg_params.scanning_period = val;
353	}
354
355	if (of_property_read_u32(np, "debounce_timeout", &val) >= 0) {
356		if (val > 255) {
357			dev_err(dev, "debounce_timeout (%u) must be [0-255]\n",
358				val);
359			return -EINVAL;
360		}
361		priv->cfg_params.debounce_timeout = val;
362	}
363
364	if (of_property_read_u32(np, "settling_timeout", &val) >= 0) {
365		if (val > 11) {
366			dev_err(dev, "settling_timeout (%u) must be [0-11]\n",
367				val);
368			return -EINVAL;
369		}
370		priv->cfg_params.settling_timeout = val;
371	}
372
373	if (of_property_read_u32(np, "touch_timeout", &val) >= 0) {
374		if (val > 255) {
375			dev_err(dev, "touch_timeout (%u) must be [0-255]\n",
376				val);
377			return -EINVAL;
378		}
379		priv->cfg_params.touch_timeout = val;
380	}
381
382	if (of_property_read_u32(np, "average_data", &val) >= 0) {
383		if (val > 8) {
384			dev_err(dev, "average_data (%u) must be [0-8]\n", val);
385			return -EINVAL;
386		}
387		priv->cfg_params.average_data = val;
388	}
389
390	if (of_property_read_u32(np, "fifo_threshold", &val) >= 0) {
391		if (val > 31) {
392			dev_err(dev, "fifo_threshold (%u)) must be [0-31]\n",
393				val);
394			return -EINVAL;
395		}
396		priv->cfg_params.fifo_threshold = val;
397	}
398
399	/* Parse optional properties. */
400	of_property_read_u32(np, "touchscreen-size-x", &priv->cfg_params.max_x);
401	of_property_read_u32(np, "touchscreen-size-y", &priv->cfg_params.max_y);
402
403	of_property_read_u32(np, "touchscreen-fuzz-x",
404			     &priv->cfg_params.fuzz_x);
405	of_property_read_u32(np, "touchscreen-fuzz-y",
406			     &priv->cfg_params.fuzz_y);
407
408	priv->cfg_params.invert_x =
409		of_property_read_bool(np, "touchscreen-inverted-x");
410	priv->cfg_params.invert_y =
411		of_property_read_bool(np, "touchscreen-inverted-y");
412
413	return 0;
414}
415
416static int iproc_ts_probe(struct platform_device *pdev)
417{
418	struct iproc_ts_priv *priv;
419	struct input_dev *idev;
420	int irq;
421	int error;
422
423	priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
424	if (!priv)
425		return -ENOMEM;
426
427	/* touchscreen controller memory mapped regs via syscon*/
428	priv->regmap = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
429							"ts_syscon");
430	if (IS_ERR(priv->regmap)) {
431		error = PTR_ERR(priv->regmap);
432		dev_err(&pdev->dev, "unable to map I/O memory:%d\n", error);
433		return error;
434	}
435
436	priv->tsc_clk = devm_clk_get(&pdev->dev, "tsc_clk");
437	if (IS_ERR(priv->tsc_clk)) {
438		error = PTR_ERR(priv->tsc_clk);
439		dev_err(&pdev->dev,
440			"failed getting clock tsc_clk: %d\n", error);
441		return error;
442	}
443
444	priv->pdev = pdev;
445	error = iproc_get_tsc_config(&pdev->dev, priv);
446	if (error) {
447		dev_err(&pdev->dev, "get_tsc_config failed: %d\n", error);
448		return error;
449	}
450
451	idev = devm_input_allocate_device(&pdev->dev);
452	if (!idev) {
453		dev_err(&pdev->dev, "failed to allocate input device\n");
454		return -ENOMEM;
455	}
456
457	priv->idev = idev;
458	priv->pen_status = PEN_UP_STATUS;
459
460	/* Set input device info  */
461	idev->name = IPROC_TS_NAME;
462	idev->dev.parent = &pdev->dev;
463
464	idev->id.bustype = BUS_HOST;
465	idev->id.vendor = SERIO_UNKNOWN;
466	idev->id.product = 0;
467	idev->id.version = 0;
468
469	idev->evbit[0] = BIT_MASK(EV_KEY) | BIT_MASK(EV_ABS);
470	__set_bit(BTN_TOUCH, idev->keybit);
471
472	input_set_abs_params(idev, ABS_X, X_MIN, priv->cfg_params.max_x,
473			     priv->cfg_params.fuzz_x, 0);
474	input_set_abs_params(idev, ABS_Y, Y_MIN, priv->cfg_params.max_y,
475			     priv->cfg_params.fuzz_y, 0);
476
477	idev->open = iproc_ts_start;
478	idev->close = iproc_ts_stop;
479
480	input_set_drvdata(idev, priv);
481	platform_set_drvdata(pdev, priv);
482
483	/* get interrupt */
484	irq = platform_get_irq(pdev, 0);
485	if (irq < 0)
486		return irq;
487
488	error = devm_request_irq(&pdev->dev, irq,
489				 iproc_touchscreen_interrupt,
490				 IRQF_SHARED, IPROC_TS_NAME, pdev);
491	if (error)
492		return error;
493
494	error = input_register_device(priv->idev);
495	if (error) {
496		dev_err(&pdev->dev,
497			"failed to register input device: %d\n", error);
498		return error;
499	}
500
501	return 0;
502}
503
504static const struct of_device_id iproc_ts_of_match[] = {
505	{.compatible = "brcm,iproc-touchscreen", },
506	{ },
507};
508MODULE_DEVICE_TABLE(of, iproc_ts_of_match);
509
510static struct platform_driver iproc_ts_driver = {
511	.probe = iproc_ts_probe,
512	.driver = {
513		.name	= IPROC_TS_NAME,
514		.of_match_table = iproc_ts_of_match,
515	},
516};
517
518module_platform_driver(iproc_ts_driver);
519
520MODULE_DESCRIPTION("IPROC Touchscreen driver");
521MODULE_AUTHOR("Broadcom");
522MODULE_LICENSE("GPL v2");
523