1 /*
2  * Core driver for WM8400.
3  *
4  * Copyright 2008 Wolfson Microelectronics PLC.
5  *
6  * Author: Mark Brown <broonie@opensource.wolfsonmicro.com>
7  *
8  * This program is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU General Public License as
10  * published by the Free Software Foundation; either version 2 of the
11  * License, or (at your option) any later version.
12  *
13  */
14 
15 #include <linux/bug.h>
16 #include <linux/i2c.h>
17 #include <linux/kernel.h>
18 #include <linux/mfd/core.h>
19 #include <linux/mfd/wm8400-private.h>
20 #include <linux/mfd/wm8400-audio.h>
21 #include <linux/slab.h>
22 
23 static struct {
24 	u16  readable;    /* Mask of readable bits */
25 	u16  writable;    /* Mask of writable bits */
26 	u16  vol;         /* Mask of volatile bits */
27 	int  is_codec;    /* Register controlled by codec reset */
28 	u16  default_val; /* Value on reset */
29 } reg_data[] = {
30 	{ 0xFFFF, 0xFFFF, 0x0000, 0, 0x6172 }, /* R0 */
31 	{ 0x7000, 0x0000, 0x8000, 0, 0x0000 }, /* R1 */
32 	{ 0xFF17, 0xFF17, 0x0000, 0, 0x0000 }, /* R2 */
33 	{ 0xEBF3, 0xEBF3, 0x0000, 1, 0x6000 }, /* R3 */
34 	{ 0x3CF3, 0x3CF3, 0x0000, 1, 0x0000 }, /* R4  */
35 	{ 0xF1F8, 0xF1F8, 0x0000, 1, 0x4050 }, /* R5  */
36 	{ 0xFC1F, 0xFC1F, 0x0000, 1, 0x4000 }, /* R6  */
37 	{ 0xDFDE, 0xDFDE, 0x0000, 1, 0x01C8 }, /* R7  */
38 	{ 0xFCFC, 0xFCFC, 0x0000, 1, 0x0000 }, /* R8  */
39 	{ 0xEFFF, 0xEFFF, 0x0000, 1, 0x0040 }, /* R9  */
40 	{ 0xEFFF, 0xEFFF, 0x0000, 1, 0x0040 }, /* R10 */
41 	{ 0x27F7, 0x27F7, 0x0000, 1, 0x0004 }, /* R11 */
42 	{ 0x01FF, 0x01FF, 0x0000, 1, 0x00C0 }, /* R12 */
43 	{ 0x01FF, 0x01FF, 0x0000, 1, 0x00C0 }, /* R13 */
44 	{ 0x1FEF, 0x1FEF, 0x0000, 1, 0x0000 }, /* R14 */
45 	{ 0x0163, 0x0163, 0x0000, 1, 0x0100 }, /* R15 */
46 	{ 0x01FF, 0x01FF, 0x0000, 1, 0x00C0 }, /* R16 */
47 	{ 0x01FF, 0x01FF, 0x0000, 1, 0x00C0 }, /* R17 */
48 	{ 0x1FFF, 0x0FFF, 0x0000, 1, 0x0000 }, /* R18 */
49 	{ 0xFFFF, 0xFFFF, 0x0000, 1, 0x1000 }, /* R19 */
50 	{ 0xFFFF, 0xFFFF, 0x0000, 1, 0x1010 }, /* R20 */
51 	{ 0xFFFF, 0xFFFF, 0x0000, 1, 0x1010 }, /* R21 */
52 	{ 0x0FDD, 0x0FDD, 0x0000, 1, 0x8000 }, /* R22 */
53 	{ 0x1FFF, 0x1FFF, 0x0000, 1, 0x0800 }, /* R23 */
54 	{ 0x0000, 0x01DF, 0x0000, 1, 0x008B }, /* R24 */
55 	{ 0x0000, 0x01DF, 0x0000, 1, 0x008B }, /* R25 */
56 	{ 0x0000, 0x01DF, 0x0000, 1, 0x008B }, /* R26 */
57 	{ 0x0000, 0x01DF, 0x0000, 1, 0x008B }, /* R27 */
58 	{ 0x0000, 0x01FF, 0x0000, 1, 0x0000 }, /* R28 */
59 	{ 0x0000, 0x01FF, 0x0000, 1, 0x0000 }, /* R29 */
60 	{ 0x0000, 0x0077, 0x0000, 1, 0x0066 }, /* R30 */
61 	{ 0x0000, 0x0033, 0x0000, 1, 0x0022 }, /* R31 */
62 	{ 0x0000, 0x01FF, 0x0000, 1, 0x0079 }, /* R32 */
63 	{ 0x0000, 0x01FF, 0x0000, 1, 0x0079 }, /* R33 */
64 	{ 0x0000, 0x0003, 0x0000, 1, 0x0003 }, /* R34 */
65 	{ 0x0000, 0x01FF, 0x0000, 1, 0x0003 }, /* R35 */
66 	{ 0x0000, 0x0000, 0x0000, 0, 0x0000 }, /* R36 */
67 	{ 0x0000, 0x003F, 0x0000, 1, 0x0100 }, /* R37 */
68 	{ 0x0000, 0x0000, 0x0000, 0, 0x0000 }, /* R38 */
69 	{ 0x0000, 0x000F, 0x0000, 0, 0x0000 }, /* R39 */
70 	{ 0x0000, 0x00FF, 0x0000, 1, 0x0000 }, /* R40 */
71 	{ 0x0000, 0x01B7, 0x0000, 1, 0x0000 }, /* R41 */
72 	{ 0x0000, 0x01B7, 0x0000, 1, 0x0000 }, /* R42 */
73 	{ 0x0000, 0x01FF, 0x0000, 1, 0x0000 }, /* R43 */
74 	{ 0x0000, 0x01FF, 0x0000, 1, 0x0000 }, /* R44 */
75 	{ 0x0000, 0x00FD, 0x0000, 1, 0x0000 }, /* R45 */
76 	{ 0x0000, 0x00FD, 0x0000, 1, 0x0000 }, /* R46 */
77 	{ 0x0000, 0x01FF, 0x0000, 1, 0x0000 }, /* R47 */
78 	{ 0x0000, 0x01FF, 0x0000, 1, 0x0000 }, /* R48 */
79 	{ 0x0000, 0x01FF, 0x0000, 1, 0x0000 }, /* R49 */
80 	{ 0x0000, 0x01FF, 0x0000, 1, 0x0000 }, /* R50 */
81 	{ 0x0000, 0x01B3, 0x0000, 1, 0x0180 }, /* R51 */
82 	{ 0x0000, 0x0077, 0x0000, 1, 0x0000 }, /* R52 */
83 	{ 0x0000, 0x0077, 0x0000, 1, 0x0000 }, /* R53 */
84 	{ 0x0000, 0x00FF, 0x0000, 1, 0x0000 }, /* R54 */
85 	{ 0x0000, 0x0001, 0x0000, 1, 0x0000 }, /* R55 */
86 	{ 0x0000, 0x003F, 0x0000, 1, 0x0000 }, /* R56 */
87 	{ 0x0000, 0x004F, 0x0000, 1, 0x0000 }, /* R57 */
88 	{ 0x0000, 0x00FD, 0x0000, 1, 0x0000 }, /* R58 */
89 	{ 0x0000, 0x0000, 0x0000, 0, 0x0000 }, /* R59 */
90 	{ 0x1FFF, 0x1FFF, 0x0000, 1, 0x0000 }, /* R60 */
91 	{ 0xFFFF, 0xFFFF, 0x0000, 1, 0x0000 }, /* R61 */
92 	{ 0x03FF, 0x03FF, 0x0000, 1, 0x0000 }, /* R62 */
93 	{ 0x007F, 0x007F, 0x0000, 1, 0x0000 }, /* R63 */
94 	{ 0x0000, 0x0000, 0x0000, 0, 0x0000 }, /* R64 */
95 	{ 0xDFFF, 0xDFFF, 0x0000, 0, 0x0000 }, /* R65 */
96 	{ 0xDFFF, 0xDFFF, 0x0000, 0, 0x0000 }, /* R66 */
97 	{ 0xDFFF, 0xDFFF, 0x0000, 0, 0x0000 }, /* R67 */
98 	{ 0xDFFF, 0xDFFF, 0x0000, 0, 0x0000 }, /* R68 */
99 	{ 0x0000, 0x0000, 0x0000, 0, 0x0000 }, /* R69 */
100 	{ 0xFFFF, 0xFFFF, 0x0000, 0, 0x4400 }, /* R70 */
101 	{ 0x23FF, 0x23FF, 0x0000, 0, 0x0000 }, /* R71 */
102 	{ 0xFFFF, 0xFFFF, 0x0000, 0, 0x4400 }, /* R72 */
103 	{ 0x23FF, 0x23FF, 0x0000, 0, 0x0000 }, /* R73 */
104 	{ 0x0000, 0x0000, 0x0000, 0, 0x0000 }, /* R74 */
105 	{ 0x000E, 0x000E, 0x0000, 0, 0x0008 }, /* R75 */
106 	{ 0xE00F, 0xE00F, 0x0000, 0, 0x0000 }, /* R76 */
107 	{ 0x0000, 0x0000, 0x0000, 0, 0x0000 }, /* R77 */
108 	{ 0x03C0, 0x03C0, 0x0000, 0, 0x02C0 }, /* R78 */
109 	{ 0xFFFF, 0x0000, 0xffff, 0, 0x0000 }, /* R79 */
110 	{ 0xFFFF, 0xFFFF, 0x0000, 0, 0x0000 }, /* R80 */
111 	{ 0xFFFF, 0x0000, 0xffff, 0, 0x0000 }, /* R81 */
112 	{ 0x2BFF, 0x0000, 0xffff, 0, 0x0000 }, /* R82 */
113 	{ 0x0000, 0x0000, 0x0000, 0, 0x0000 }, /* R83 */
114 	{ 0x80FF, 0x80FF, 0x0000, 0, 0x00ff }, /* R84 */
115 };
116 
wm8400_read(struct wm8400 * wm8400,u8 reg,int num_regs,u16 * dest)117 static int wm8400_read(struct wm8400 *wm8400, u8 reg, int num_regs, u16 *dest)
118 {
119 	int i, ret = 0;
120 
121 	BUG_ON(reg + num_regs > ARRAY_SIZE(wm8400->reg_cache));
122 
123 	/* If there are any volatile reads then read back the entire block */
124 	for (i = reg; i < reg + num_regs; i++)
125 		if (reg_data[i].vol) {
126 			ret = wm8400->read_dev(wm8400->io_data, reg,
127 					       num_regs, dest);
128 			if (ret != 0)
129 				return ret;
130 			for (i = 0; i < num_regs; i++)
131 				dest[i] = be16_to_cpu(dest[i]);
132 
133 			return 0;
134 		}
135 
136 	/* Otherwise use the cache */
137 	memcpy(dest, &wm8400->reg_cache[reg], num_regs * sizeof(u16));
138 
139 	return 0;
140 }
141 
wm8400_write(struct wm8400 * wm8400,u8 reg,int num_regs,u16 * src)142 static int wm8400_write(struct wm8400 *wm8400, u8 reg, int num_regs,
143 			u16 *src)
144 {
145 	int ret, i;
146 
147 	BUG_ON(reg + num_regs > ARRAY_SIZE(wm8400->reg_cache));
148 
149 	for (i = 0; i < num_regs; i++) {
150 		BUG_ON(!reg_data[reg + i].writable);
151 		wm8400->reg_cache[reg + i] = src[i];
152 		src[i] = cpu_to_be16(src[i]);
153 	}
154 
155 	/* Do the actual I/O */
156 	ret = wm8400->write_dev(wm8400->io_data, reg, num_regs, src);
157 	if (ret != 0)
158 		return -EIO;
159 
160 	return 0;
161 }
162 
163 /**
164  * wm8400_reg_read - Single register read
165  *
166  * @wm8400: Pointer to wm8400 control structure
167  * @reg:    Register to read
168  *
169  * @return  Read value
170  */
wm8400_reg_read(struct wm8400 * wm8400,u8 reg)171 u16 wm8400_reg_read(struct wm8400 *wm8400, u8 reg)
172 {
173 	u16 val;
174 
175 	mutex_lock(&wm8400->io_lock);
176 
177 	wm8400_read(wm8400, reg, 1, &val);
178 
179 	mutex_unlock(&wm8400->io_lock);
180 
181 	return val;
182 }
183 EXPORT_SYMBOL_GPL(wm8400_reg_read);
184 
wm8400_block_read(struct wm8400 * wm8400,u8 reg,int count,u16 * data)185 int wm8400_block_read(struct wm8400 *wm8400, u8 reg, int count, u16 *data)
186 {
187 	int ret;
188 
189 	mutex_lock(&wm8400->io_lock);
190 
191 	ret = wm8400_read(wm8400, reg, count, data);
192 
193 	mutex_unlock(&wm8400->io_lock);
194 
195 	return ret;
196 }
197 EXPORT_SYMBOL_GPL(wm8400_block_read);
198 
199 /**
200  * wm8400_set_bits - Bitmask write
201  *
202  * @wm8400: Pointer to wm8400 control structure
203  * @reg:    Register to access
204  * @mask:   Mask of bits to change
205  * @val:    Value to set for masked bits
206  */
wm8400_set_bits(struct wm8400 * wm8400,u8 reg,u16 mask,u16 val)207 int wm8400_set_bits(struct wm8400 *wm8400, u8 reg, u16 mask, u16 val)
208 {
209 	u16 tmp;
210 	int ret;
211 
212 	mutex_lock(&wm8400->io_lock);
213 
214 	ret = wm8400_read(wm8400, reg, 1, &tmp);
215 	tmp = (tmp & ~mask) | val;
216 	if (ret == 0)
217 		ret = wm8400_write(wm8400, reg, 1, &tmp);
218 
219 	mutex_unlock(&wm8400->io_lock);
220 
221 	return ret;
222 }
223 EXPORT_SYMBOL_GPL(wm8400_set_bits);
224 
225 /**
226  * wm8400_reset_codec_reg_cache - Reset cached codec registers to
227  * their default values.
228  */
wm8400_reset_codec_reg_cache(struct wm8400 * wm8400)229 void wm8400_reset_codec_reg_cache(struct wm8400 *wm8400)
230 {
231 	int i;
232 
233 	mutex_lock(&wm8400->io_lock);
234 
235 	/* Reset all codec registers to their initial value */
236 	for (i = 0; i < ARRAY_SIZE(wm8400->reg_cache); i++)
237 		if (reg_data[i].is_codec)
238 			wm8400->reg_cache[i] = reg_data[i].default_val;
239 
240 	mutex_unlock(&wm8400->io_lock);
241 }
242 EXPORT_SYMBOL_GPL(wm8400_reset_codec_reg_cache);
243 
wm8400_register_codec(struct wm8400 * wm8400)244 static int wm8400_register_codec(struct wm8400 *wm8400)
245 {
246 	struct mfd_cell cell = {
247 		.name = "wm8400-codec",
248 		.mfd_data = wm8400,
249 	};
250 
251 	return mfd_add_devices(wm8400->dev, -1, &cell, 1, NULL, 0);
252 }
253 
254 /*
255  * wm8400_init - Generic initialisation
256  *
257  * The WM8400 can be configured as either an I2C or SPI device.  Probe
258  * functions for each bus set up the accessors then call into this to
259  * set up the device itself.
260  */
wm8400_init(struct wm8400 * wm8400,struct wm8400_platform_data * pdata)261 static int wm8400_init(struct wm8400 *wm8400,
262 		       struct wm8400_platform_data *pdata)
263 {
264 	u16 reg;
265 	int ret, i;
266 
267 	mutex_init(&wm8400->io_lock);
268 
269 	dev_set_drvdata(wm8400->dev, wm8400);
270 
271 	/* Check that this is actually a WM8400 */
272 	ret = wm8400->read_dev(wm8400->io_data, WM8400_RESET_ID, 1, &reg);
273 	if (ret != 0) {
274 		dev_err(wm8400->dev, "Chip ID register read failed\n");
275 		return -EIO;
276 	}
277 	if (be16_to_cpu(reg) != reg_data[WM8400_RESET_ID].default_val) {
278 		dev_err(wm8400->dev, "Device is not a WM8400, ID is %x\n",
279 			be16_to_cpu(reg));
280 		return -ENODEV;
281 	}
282 
283 	/* We don't know what state the hardware is in and since this
284 	 * is a PMIC we can't reset it safely so initialise the register
285 	 * cache from the hardware.
286 	 */
287 	ret = wm8400->read_dev(wm8400->io_data, 0,
288 			       ARRAY_SIZE(wm8400->reg_cache),
289 			       wm8400->reg_cache);
290 	if (ret != 0) {
291 		dev_err(wm8400->dev, "Register cache read failed\n");
292 		return -EIO;
293 	}
294 	for (i = 0; i < ARRAY_SIZE(wm8400->reg_cache); i++)
295 		wm8400->reg_cache[i] = be16_to_cpu(wm8400->reg_cache[i]);
296 
297 	/* If the codec is in reset use hard coded values */
298 	if (!(wm8400->reg_cache[WM8400_POWER_MANAGEMENT_1] & WM8400_CODEC_ENA))
299 		for (i = 0; i < ARRAY_SIZE(wm8400->reg_cache); i++)
300 			if (reg_data[i].is_codec)
301 				wm8400->reg_cache[i] = reg_data[i].default_val;
302 
303 	ret = wm8400_read(wm8400, WM8400_ID, 1, &reg);
304 	if (ret != 0) {
305 		dev_err(wm8400->dev, "ID register read failed: %d\n", ret);
306 		return ret;
307 	}
308 	reg = (reg & WM8400_CHIP_REV_MASK) >> WM8400_CHIP_REV_SHIFT;
309 	dev_info(wm8400->dev, "WM8400 revision %x\n", reg);
310 
311 	ret = wm8400_register_codec(wm8400);
312 	if (ret != 0) {
313 		dev_err(wm8400->dev, "Failed to register codec\n");
314 		goto err_children;
315 	}
316 
317 	if (pdata && pdata->platform_init) {
318 		ret = pdata->platform_init(wm8400->dev);
319 		if (ret != 0) {
320 			dev_err(wm8400->dev, "Platform init failed: %d\n",
321 				ret);
322 			goto err_children;
323 		}
324 	} else
325 		dev_warn(wm8400->dev, "No platform initialisation supplied\n");
326 
327 	return 0;
328 
329 err_children:
330 	mfd_remove_devices(wm8400->dev);
331 	return ret;
332 }
333 
wm8400_release(struct wm8400 * wm8400)334 static void wm8400_release(struct wm8400 *wm8400)
335 {
336 	mfd_remove_devices(wm8400->dev);
337 }
338 
339 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
wm8400_i2c_read(void * io_data,char reg,int count,u16 * dest)340 static int wm8400_i2c_read(void *io_data, char reg, int count, u16 *dest)
341 {
342 	struct i2c_client *i2c = io_data;
343 	struct i2c_msg xfer[2];
344 	int ret;
345 
346 	/* Write register */
347 	xfer[0].addr = i2c->addr;
348 	xfer[0].flags = 0;
349 	xfer[0].len = 1;
350 	xfer[0].buf = &reg;
351 
352 	/* Read data */
353 	xfer[1].addr = i2c->addr;
354 	xfer[1].flags = I2C_M_RD;
355 	xfer[1].len = count * sizeof(u16);
356 	xfer[1].buf = (u8 *)dest;
357 
358 	ret = i2c_transfer(i2c->adapter, xfer, 2);
359 	if (ret == 2)
360 		ret = 0;
361 	else if (ret >= 0)
362 		ret = -EIO;
363 
364 	return ret;
365 }
366 
wm8400_i2c_write(void * io_data,char reg,int count,const u16 * src)367 static int wm8400_i2c_write(void *io_data, char reg, int count, const u16 *src)
368 {
369 	struct i2c_client *i2c = io_data;
370 	u8 *msg;
371 	int ret;
372 
373 	/* We add 1 byte for device register - ideally I2C would gather. */
374 	msg = kmalloc((count * sizeof(u16)) + 1, GFP_KERNEL);
375 	if (msg == NULL)
376 		return -ENOMEM;
377 
378 	msg[0] = reg;
379 	memcpy(&msg[1], src, count * sizeof(u16));
380 
381 	ret = i2c_master_send(i2c, msg, (count * sizeof(u16)) + 1);
382 
383 	if (ret == (count * 2) + 1)
384 		ret = 0;
385 	else if (ret >= 0)
386 		ret = -EIO;
387 
388 	kfree(msg);
389 
390 	return ret;
391 }
392 
wm8400_i2c_probe(struct i2c_client * i2c,const struct i2c_device_id * id)393 static int wm8400_i2c_probe(struct i2c_client *i2c,
394 			    const struct i2c_device_id *id)
395 {
396 	struct wm8400 *wm8400;
397 	int ret;
398 
399 	wm8400 = kzalloc(sizeof(struct wm8400), GFP_KERNEL);
400 	if (wm8400 == NULL) {
401 		ret = -ENOMEM;
402 		goto err;
403 	}
404 
405 	wm8400->io_data = i2c;
406 	wm8400->read_dev = wm8400_i2c_read;
407 	wm8400->write_dev = wm8400_i2c_write;
408 	wm8400->dev = &i2c->dev;
409 	i2c_set_clientdata(i2c, wm8400);
410 
411 	ret = wm8400_init(wm8400, i2c->dev.platform_data);
412 	if (ret != 0)
413 		goto struct_err;
414 
415 	return 0;
416 
417 struct_err:
418 	kfree(wm8400);
419 err:
420 	return ret;
421 }
422 
wm8400_i2c_remove(struct i2c_client * i2c)423 static int wm8400_i2c_remove(struct i2c_client *i2c)
424 {
425 	struct wm8400 *wm8400 = i2c_get_clientdata(i2c);
426 
427 	wm8400_release(wm8400);
428 	kfree(wm8400);
429 
430 	return 0;
431 }
432 
433 static const struct i2c_device_id wm8400_i2c_id[] = {
434        { "wm8400", 0 },
435        { }
436 };
437 MODULE_DEVICE_TABLE(i2c, wm8400_i2c_id);
438 
439 static struct i2c_driver wm8400_i2c_driver = {
440 	.driver = {
441 		.name = "WM8400",
442 		.owner = THIS_MODULE,
443 	},
444 	.probe    = wm8400_i2c_probe,
445 	.remove   = wm8400_i2c_remove,
446 	.id_table = wm8400_i2c_id,
447 };
448 #endif
449 
wm8400_module_init(void)450 static int __init wm8400_module_init(void)
451 {
452 	int ret = -ENODEV;
453 
454 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
455 	ret = i2c_add_driver(&wm8400_i2c_driver);
456 	if (ret != 0)
457 		pr_err("Failed to register I2C driver: %d\n", ret);
458 #endif
459 
460 	return ret;
461 }
462 subsys_initcall(wm8400_module_init);
463 
wm8400_module_exit(void)464 static void __exit wm8400_module_exit(void)
465 {
466 #if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
467 	i2c_del_driver(&wm8400_i2c_driver);
468 #endif
469 }
470 module_exit(wm8400_module_exit);
471 
472 MODULE_LICENSE("GPL");
473 MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
474