1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Lochnagar I2C bus interface
4 *
5 * Copyright (c) 2012-2018 Cirrus Logic, Inc. and
6 *                         Cirrus Logic International Semiconductor Ltd.
7 *
8 * Author: Charles Keepax <ckeepax@opensource.cirrus.com>
9 */
10
11#include <linux/delay.h>
12#include <linux/device.h>
13#include <linux/err.h>
14#include <linux/gpio/consumer.h>
15#include <linux/i2c.h>
16#include <linux/lockdep.h>
17#include <linux/mfd/core.h>
18#include <linux/mod_devicetable.h>
19#include <linux/mutex.h>
20#include <linux/of_platform.h>
21#include <linux/regmap.h>
22
23#include <linux/mfd/lochnagar.h>
24#include <linux/mfd/lochnagar1_regs.h>
25#include <linux/mfd/lochnagar2_regs.h>
26
27#define LOCHNAGAR_BOOT_RETRIES		10
28#define LOCHNAGAR_BOOT_DELAY_MS		350
29
30#define LOCHNAGAR_CONFIG_POLL_US	10000
31
32static bool lochnagar1_readable_register(struct device *dev, unsigned int reg)
33{
34	switch (reg) {
35	case LOCHNAGAR_SOFTWARE_RESET:
36	case LOCHNAGAR_FIRMWARE_ID1...LOCHNAGAR_FIRMWARE_ID2:
37	case LOCHNAGAR1_CDC_AIF1_SEL...LOCHNAGAR1_CDC_AIF3_SEL:
38	case LOCHNAGAR1_CDC_MCLK1_SEL...LOCHNAGAR1_CDC_MCLK2_SEL:
39	case LOCHNAGAR1_CDC_AIF_CTRL1...LOCHNAGAR1_CDC_AIF_CTRL2:
40	case LOCHNAGAR1_EXT_AIF_CTRL:
41	case LOCHNAGAR1_DSP_AIF1_SEL...LOCHNAGAR1_DSP_AIF2_SEL:
42	case LOCHNAGAR1_DSP_CLKIN_SEL:
43	case LOCHNAGAR1_DSP_AIF:
44	case LOCHNAGAR1_GF_AIF1...LOCHNAGAR1_GF_AIF2:
45	case LOCHNAGAR1_PSIA_AIF:
46	case LOCHNAGAR1_PSIA1_SEL...LOCHNAGAR1_PSIA2_SEL:
47	case LOCHNAGAR1_SPDIF_AIF_SEL:
48	case LOCHNAGAR1_GF_AIF3_SEL...LOCHNAGAR1_GF_AIF4_SEL:
49	case LOCHNAGAR1_GF_CLKOUT1_SEL:
50	case LOCHNAGAR1_GF_AIF1_SEL...LOCHNAGAR1_GF_AIF2_SEL:
51	case LOCHNAGAR1_GF_GPIO2...LOCHNAGAR1_GF_GPIO7:
52	case LOCHNAGAR1_RST:
53	case LOCHNAGAR1_LED1...LOCHNAGAR1_LED2:
54	case LOCHNAGAR1_I2C_CTRL:
55		return true;
56	default:
57		return false;
58	}
59}
60
61static const struct regmap_config lochnagar1_i2c_regmap = {
62	.reg_bits = 8,
63	.val_bits = 8,
64	.reg_format_endian = REGMAP_ENDIAN_BIG,
65	.val_format_endian = REGMAP_ENDIAN_BIG,
66
67	.max_register = 0x50,
68	.readable_reg = lochnagar1_readable_register,
69
70	.use_single_read = true,
71	.use_single_write = true,
72
73	.cache_type = REGCACHE_MAPLE,
74};
75
76static const struct reg_sequence lochnagar1_patch[] = {
77	{ 0x40, 0x0083 },
78	{ 0x47, 0x0018 },
79	{ 0x50, 0x0000 },
80};
81
82static bool lochnagar2_readable_register(struct device *dev, unsigned int reg)
83{
84	switch (reg) {
85	case LOCHNAGAR_SOFTWARE_RESET:
86	case LOCHNAGAR_FIRMWARE_ID1...LOCHNAGAR_FIRMWARE_ID2:
87	case LOCHNAGAR2_CDC_AIF1_CTRL...LOCHNAGAR2_CDC_AIF3_CTRL:
88	case LOCHNAGAR2_DSP_AIF1_CTRL...LOCHNAGAR2_DSP_AIF2_CTRL:
89	case LOCHNAGAR2_PSIA1_CTRL...LOCHNAGAR2_PSIA2_CTRL:
90	case LOCHNAGAR2_GF_AIF3_CTRL...LOCHNAGAR2_GF_AIF4_CTRL:
91	case LOCHNAGAR2_GF_AIF1_CTRL...LOCHNAGAR2_GF_AIF2_CTRL:
92	case LOCHNAGAR2_SPDIF_AIF_CTRL:
93	case LOCHNAGAR2_USB_AIF1_CTRL...LOCHNAGAR2_USB_AIF2_CTRL:
94	case LOCHNAGAR2_ADAT_AIF_CTRL:
95	case LOCHNAGAR2_CDC_MCLK1_CTRL...LOCHNAGAR2_CDC_MCLK2_CTRL:
96	case LOCHNAGAR2_DSP_CLKIN_CTRL:
97	case LOCHNAGAR2_PSIA1_MCLK_CTRL...LOCHNAGAR2_PSIA2_MCLK_CTRL:
98	case LOCHNAGAR2_SPDIF_MCLK_CTRL:
99	case LOCHNAGAR2_GF_CLKOUT1_CTRL...LOCHNAGAR2_GF_CLKOUT2_CTRL:
100	case LOCHNAGAR2_ADAT_MCLK_CTRL:
101	case LOCHNAGAR2_SOUNDCARD_MCLK_CTRL:
102	case LOCHNAGAR2_GPIO_FPGA_GPIO1...LOCHNAGAR2_GPIO_FPGA_GPIO6:
103	case LOCHNAGAR2_GPIO_CDC_GPIO1...LOCHNAGAR2_GPIO_CDC_GPIO8:
104	case LOCHNAGAR2_GPIO_DSP_GPIO1...LOCHNAGAR2_GPIO_DSP_GPIO6:
105	case LOCHNAGAR2_GPIO_GF_GPIO2...LOCHNAGAR2_GPIO_GF_GPIO7:
106	case LOCHNAGAR2_GPIO_CDC_AIF1_BCLK...LOCHNAGAR2_GPIO_CDC_AIF3_TXDAT:
107	case LOCHNAGAR2_GPIO_DSP_AIF1_BCLK...LOCHNAGAR2_GPIO_DSP_AIF2_TXDAT:
108	case LOCHNAGAR2_GPIO_PSIA1_BCLK...LOCHNAGAR2_GPIO_PSIA2_TXDAT:
109	case LOCHNAGAR2_GPIO_GF_AIF3_BCLK...LOCHNAGAR2_GPIO_GF_AIF4_TXDAT:
110	case LOCHNAGAR2_GPIO_GF_AIF1_BCLK...LOCHNAGAR2_GPIO_GF_AIF2_TXDAT:
111	case LOCHNAGAR2_GPIO_DSP_UART1_RX...LOCHNAGAR2_GPIO_DSP_UART2_TX:
112	case LOCHNAGAR2_GPIO_GF_UART2_RX...LOCHNAGAR2_GPIO_GF_UART2_TX:
113	case LOCHNAGAR2_GPIO_USB_UART_RX:
114	case LOCHNAGAR2_GPIO_CDC_PDMCLK1...LOCHNAGAR2_GPIO_CDC_PDMDAT2:
115	case LOCHNAGAR2_GPIO_CDC_DMICCLK1...LOCHNAGAR2_GPIO_CDC_DMICDAT4:
116	case LOCHNAGAR2_GPIO_DSP_DMICCLK1...LOCHNAGAR2_GPIO_DSP_DMICDAT2:
117	case LOCHNAGAR2_GPIO_I2C2_SCL...LOCHNAGAR2_GPIO_I2C4_SDA:
118	case LOCHNAGAR2_GPIO_DSP_STANDBY:
119	case LOCHNAGAR2_GPIO_CDC_MCLK1...LOCHNAGAR2_GPIO_CDC_MCLK2:
120	case LOCHNAGAR2_GPIO_DSP_CLKIN:
121	case LOCHNAGAR2_GPIO_PSIA1_MCLK...LOCHNAGAR2_GPIO_PSIA2_MCLK:
122	case LOCHNAGAR2_GPIO_GF_GPIO1...LOCHNAGAR2_GPIO_GF_GPIO5:
123	case LOCHNAGAR2_GPIO_DSP_GPIO20:
124	case LOCHNAGAR2_GPIO_CHANNEL1...LOCHNAGAR2_GPIO_CHANNEL16:
125	case LOCHNAGAR2_MINICARD_RESETS:
126	case LOCHNAGAR2_ANALOGUE_PATH_CTRL1...LOCHNAGAR2_ANALOGUE_PATH_CTRL2:
127	case LOCHNAGAR2_COMMS_CTRL4:
128	case LOCHNAGAR2_SPDIF_CTRL:
129	case LOCHNAGAR2_IMON_CTRL1...LOCHNAGAR2_IMON_CTRL4:
130	case LOCHNAGAR2_IMON_DATA1...LOCHNAGAR2_IMON_DATA2:
131	case LOCHNAGAR2_POWER_CTRL:
132	case LOCHNAGAR2_MICVDD_CTRL1:
133	case LOCHNAGAR2_MICVDD_CTRL2:
134	case LOCHNAGAR2_VDDCORE_CDC_CTRL1:
135	case LOCHNAGAR2_VDDCORE_CDC_CTRL2:
136	case LOCHNAGAR2_SOUNDCARD_AIF_CTRL:
137		return true;
138	default:
139		return false;
140	}
141}
142
143static bool lochnagar2_volatile_register(struct device *dev, unsigned int reg)
144{
145	switch (reg) {
146	case LOCHNAGAR2_GPIO_CHANNEL1...LOCHNAGAR2_GPIO_CHANNEL16:
147	case LOCHNAGAR2_ANALOGUE_PATH_CTRL1:
148	case LOCHNAGAR2_IMON_CTRL3...LOCHNAGAR2_IMON_CTRL4:
149	case LOCHNAGAR2_IMON_DATA1...LOCHNAGAR2_IMON_DATA2:
150		return true;
151	default:
152		return false;
153	}
154}
155
156static const struct regmap_config lochnagar2_i2c_regmap = {
157	.reg_bits = 16,
158	.val_bits = 16,
159	.reg_format_endian = REGMAP_ENDIAN_BIG,
160	.val_format_endian = REGMAP_ENDIAN_BIG,
161
162	.max_register = 0x1F1F,
163	.readable_reg = lochnagar2_readable_register,
164	.volatile_reg = lochnagar2_volatile_register,
165
166	.cache_type = REGCACHE_MAPLE,
167};
168
169static const struct reg_sequence lochnagar2_patch[] = {
170	{ 0x00EE, 0x0000 },
171};
172
173struct lochnagar_config {
174	int id;
175	const char * const name;
176	enum lochnagar_type type;
177	const struct regmap_config *regmap;
178	const struct reg_sequence *patch;
179	int npatch;
180};
181
182static struct lochnagar_config lochnagar_configs[] = {
183	{
184		.id = 0x50,
185		.name = "lochnagar1",
186		.type = LOCHNAGAR1,
187		.regmap = &lochnagar1_i2c_regmap,
188		.patch = lochnagar1_patch,
189		.npatch = ARRAY_SIZE(lochnagar1_patch),
190	},
191	{
192		.id = 0xCB58,
193		.name = "lochnagar2",
194		.type = LOCHNAGAR2,
195		.regmap = &lochnagar2_i2c_regmap,
196		.patch = lochnagar2_patch,
197		.npatch = ARRAY_SIZE(lochnagar2_patch),
198	},
199};
200
201static const struct of_device_id lochnagar_of_match[] = {
202	{ .compatible = "cirrus,lochnagar1", .data = &lochnagar_configs[0] },
203	{ .compatible = "cirrus,lochnagar2", .data = &lochnagar_configs[1] },
204	{},
205};
206
207static int lochnagar_wait_for_boot(struct regmap *regmap, unsigned int *id)
208{
209	int i, ret;
210
211	for (i = 0; i < LOCHNAGAR_BOOT_RETRIES; ++i) {
212		msleep(LOCHNAGAR_BOOT_DELAY_MS);
213
214		/* The reset register will return the device ID when read */
215		ret = regmap_read(regmap, LOCHNAGAR_SOFTWARE_RESET, id);
216		if (!ret)
217			return ret;
218	}
219
220	return -ETIMEDOUT;
221}
222
223/**
224 * lochnagar_update_config - Synchronise the boards analogue configuration to
225 *                           the hardware.
226 *
227 * @lochnagar: A pointer to the primary core data structure.
228 *
229 * Return: Zero on success or an appropriate negative error code on failure.
230 */
231int lochnagar_update_config(struct lochnagar *lochnagar)
232{
233	struct regmap *regmap = lochnagar->regmap;
234	unsigned int done = LOCHNAGAR2_ANALOGUE_PATH_UPDATE_STS_MASK;
235	int timeout_ms = LOCHNAGAR_BOOT_DELAY_MS * LOCHNAGAR_BOOT_RETRIES;
236	unsigned int val = 0;
237	int ret;
238
239	lockdep_assert_held(&lochnagar->analogue_config_lock);
240
241	if (lochnagar->type != LOCHNAGAR2)
242		return 0;
243
244	/*
245	 * Toggle the ANALOGUE_PATH_UPDATE bit and wait for the device to
246	 * acknowledge that any outstanding changes to the analogue
247	 * configuration have been applied.
248	 */
249	ret = regmap_write(regmap, LOCHNAGAR2_ANALOGUE_PATH_CTRL1, 0);
250	if (ret < 0)
251		return ret;
252
253	ret = regmap_write(regmap, LOCHNAGAR2_ANALOGUE_PATH_CTRL1,
254			   LOCHNAGAR2_ANALOGUE_PATH_UPDATE_MASK);
255	if (ret < 0)
256		return ret;
257
258	ret = regmap_read_poll_timeout(regmap,
259				       LOCHNAGAR2_ANALOGUE_PATH_CTRL1, val,
260				       (val & done), LOCHNAGAR_CONFIG_POLL_US,
261				       timeout_ms * 1000);
262	if (ret < 0)
263		return ret;
264
265	return 0;
266}
267EXPORT_SYMBOL_GPL(lochnagar_update_config);
268
269static int lochnagar_i2c_probe(struct i2c_client *i2c)
270{
271	struct device *dev = &i2c->dev;
272	const struct lochnagar_config *config = NULL;
273	struct lochnagar *lochnagar;
274	struct gpio_desc *reset, *present;
275	unsigned int val;
276	unsigned int firmwareid;
277	unsigned int devid, rev;
278	int ret;
279
280	lochnagar = devm_kzalloc(dev, sizeof(*lochnagar), GFP_KERNEL);
281	if (!lochnagar)
282		return -ENOMEM;
283
284	config = i2c_get_match_data(i2c);
285
286	lochnagar->dev = dev;
287	mutex_init(&lochnagar->analogue_config_lock);
288
289	dev_set_drvdata(dev, lochnagar);
290
291	reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
292	if (IS_ERR(reset)) {
293		ret = PTR_ERR(reset);
294		dev_err(dev, "Failed to get reset GPIO: %d\n", ret);
295		return ret;
296	}
297
298	present = devm_gpiod_get_optional(dev, "present", GPIOD_OUT_HIGH);
299	if (IS_ERR(present)) {
300		ret = PTR_ERR(present);
301		dev_err(dev, "Failed to get present GPIO: %d\n", ret);
302		return ret;
303	}
304
305	/* Leave the Lochnagar in reset for a reasonable amount of time */
306	msleep(20);
307
308	/* Bring Lochnagar out of reset */
309	gpiod_set_value_cansleep(reset, 1);
310
311	/* Identify Lochnagar */
312	lochnagar->type = config->type;
313
314	lochnagar->regmap = devm_regmap_init_i2c(i2c, config->regmap);
315	if (IS_ERR(lochnagar->regmap)) {
316		ret = PTR_ERR(lochnagar->regmap);
317		dev_err(dev, "Failed to allocate register map: %d\n", ret);
318		return ret;
319	}
320
321	/* Wait for Lochnagar to boot */
322	ret = lochnagar_wait_for_boot(lochnagar->regmap, &val);
323	if (ret < 0) {
324		dev_err(dev, "Failed to read device ID: %d\n", ret);
325		return ret;
326	}
327
328	devid = val & LOCHNAGAR_DEVICE_ID_MASK;
329	rev = val & LOCHNAGAR_REV_ID_MASK;
330
331	if (devid != config->id) {
332		dev_err(dev,
333			"ID does not match %s (expected 0x%x got 0x%x)\n",
334			config->name, config->id, devid);
335		return -ENODEV;
336	}
337
338	/* Identify firmware */
339	ret = regmap_read(lochnagar->regmap, LOCHNAGAR_FIRMWARE_ID1, &val);
340	if (ret < 0) {
341		dev_err(dev, "Failed to read firmware id 1: %d\n", ret);
342		return ret;
343	}
344
345	firmwareid = val;
346
347	ret = regmap_read(lochnagar->regmap, LOCHNAGAR_FIRMWARE_ID2, &val);
348	if (ret < 0) {
349		dev_err(dev, "Failed to read firmware id 2: %d\n", ret);
350		return ret;
351	}
352
353	firmwareid |= (val << config->regmap->val_bits);
354
355	dev_info(dev, "Found %s (0x%x) revision %u firmware 0x%.6x\n",
356		 config->name, devid, rev + 1, firmwareid);
357
358	ret = regmap_register_patch(lochnagar->regmap, config->patch,
359				    config->npatch);
360	if (ret < 0) {
361		dev_err(dev, "Failed to register patch: %d\n", ret);
362		return ret;
363	}
364
365	ret = devm_of_platform_populate(dev);
366	if (ret < 0) {
367		dev_err(dev, "Failed to populate child nodes: %d\n", ret);
368		return ret;
369	}
370
371	return ret;
372}
373
374static struct i2c_driver lochnagar_i2c_driver = {
375	.driver = {
376		.name = "lochnagar",
377		.of_match_table = lochnagar_of_match,
378		.suppress_bind_attrs = true,
379	},
380	.probe = lochnagar_i2c_probe,
381};
382
383static int __init lochnagar_i2c_init(void)
384{
385	int ret;
386
387	ret = i2c_add_driver(&lochnagar_i2c_driver);
388	if (ret)
389		pr_err("Failed to register Lochnagar driver: %d\n", ret);
390
391	return ret;
392}
393subsys_initcall(lochnagar_i2c_init);
394