xref: /linux/drivers/mfd/lochnagar-i2c.c (revision f9bff0e31881d03badf191d3b0005839391f5f2b)
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/mutex.h>
19 #include <linux/of.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 
32 static 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 
61 static 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_RBTREE,
74 };
75 
76 static const struct reg_sequence lochnagar1_patch[] = {
77 	{ 0x40, 0x0083 },
78 	{ 0x47, 0x0018 },
79 	{ 0x50, 0x0000 },
80 };
81 
82 static 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 
143 static 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 
156 static 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_RBTREE,
167 };
168 
169 static const struct reg_sequence lochnagar2_patch[] = {
170 	{ 0x00EE, 0x0000 },
171 };
172 
173 struct 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 
182 static 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 
201 static 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 
207 static 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  */
231 int 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 }
267 EXPORT_SYMBOL_GPL(lochnagar_update_config);
268 
269 static int lochnagar_i2c_probe(struct i2c_client *i2c)
270 {
271 	struct device *dev = &i2c->dev;
272 	const struct lochnagar_config *config = NULL;
273 	const struct of_device_id *of_id;
274 	struct lochnagar *lochnagar;
275 	struct gpio_desc *reset, *present;
276 	unsigned int val;
277 	unsigned int firmwareid;
278 	unsigned int devid, rev;
279 	int ret;
280 
281 	lochnagar = devm_kzalloc(dev, sizeof(*lochnagar), GFP_KERNEL);
282 	if (!lochnagar)
283 		return -ENOMEM;
284 
285 	of_id = of_match_device(lochnagar_of_match, dev);
286 	if (!of_id)
287 		return -EINVAL;
288 
289 	config = of_id->data;
290 
291 	lochnagar->dev = dev;
292 	mutex_init(&lochnagar->analogue_config_lock);
293 
294 	dev_set_drvdata(dev, lochnagar);
295 
296 	reset = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
297 	if (IS_ERR(reset)) {
298 		ret = PTR_ERR(reset);
299 		dev_err(dev, "Failed to get reset GPIO: %d\n", ret);
300 		return ret;
301 	}
302 
303 	present = devm_gpiod_get_optional(dev, "present", GPIOD_OUT_HIGH);
304 	if (IS_ERR(present)) {
305 		ret = PTR_ERR(present);
306 		dev_err(dev, "Failed to get present GPIO: %d\n", ret);
307 		return ret;
308 	}
309 
310 	/* Leave the Lochnagar in reset for a reasonable amount of time */
311 	msleep(20);
312 
313 	/* Bring Lochnagar out of reset */
314 	gpiod_set_value_cansleep(reset, 1);
315 
316 	/* Identify Lochnagar */
317 	lochnagar->type = config->type;
318 
319 	lochnagar->regmap = devm_regmap_init_i2c(i2c, config->regmap);
320 	if (IS_ERR(lochnagar->regmap)) {
321 		ret = PTR_ERR(lochnagar->regmap);
322 		dev_err(dev, "Failed to allocate register map: %d\n", ret);
323 		return ret;
324 	}
325 
326 	/* Wait for Lochnagar to boot */
327 	ret = lochnagar_wait_for_boot(lochnagar->regmap, &val);
328 	if (ret < 0) {
329 		dev_err(dev, "Failed to read device ID: %d\n", ret);
330 		return ret;
331 	}
332 
333 	devid = val & LOCHNAGAR_DEVICE_ID_MASK;
334 	rev = val & LOCHNAGAR_REV_ID_MASK;
335 
336 	if (devid != config->id) {
337 		dev_err(dev,
338 			"ID does not match %s (expected 0x%x got 0x%x)\n",
339 			config->name, config->id, devid);
340 		return -ENODEV;
341 	}
342 
343 	/* Identify firmware */
344 	ret = regmap_read(lochnagar->regmap, LOCHNAGAR_FIRMWARE_ID1, &val);
345 	if (ret < 0) {
346 		dev_err(dev, "Failed to read firmware id 1: %d\n", ret);
347 		return ret;
348 	}
349 
350 	firmwareid = val;
351 
352 	ret = regmap_read(lochnagar->regmap, LOCHNAGAR_FIRMWARE_ID2, &val);
353 	if (ret < 0) {
354 		dev_err(dev, "Failed to read firmware id 2: %d\n", ret);
355 		return ret;
356 	}
357 
358 	firmwareid |= (val << config->regmap->val_bits);
359 
360 	dev_info(dev, "Found %s (0x%x) revision %u firmware 0x%.6x\n",
361 		 config->name, devid, rev + 1, firmwareid);
362 
363 	ret = regmap_register_patch(lochnagar->regmap, config->patch,
364 				    config->npatch);
365 	if (ret < 0) {
366 		dev_err(dev, "Failed to register patch: %d\n", ret);
367 		return ret;
368 	}
369 
370 	ret = devm_of_platform_populate(dev);
371 	if (ret < 0) {
372 		dev_err(dev, "Failed to populate child nodes: %d\n", ret);
373 		return ret;
374 	}
375 
376 	return ret;
377 }
378 
379 static struct i2c_driver lochnagar_i2c_driver = {
380 	.driver = {
381 		.name = "lochnagar",
382 		.of_match_table = of_match_ptr(lochnagar_of_match),
383 		.suppress_bind_attrs = true,
384 	},
385 	.probe = lochnagar_i2c_probe,
386 };
387 
388 static int __init lochnagar_i2c_init(void)
389 {
390 	int ret;
391 
392 	ret = i2c_add_driver(&lochnagar_i2c_driver);
393 	if (ret)
394 		pr_err("Failed to register Lochnagar driver: %d\n", ret);
395 
396 	return ret;
397 }
398 subsys_initcall(lochnagar_i2c_init);
399