wm8994-core.c revision 5a0e3ad6af8660be21ca98a971cd00f331318c05 
1/*
2 * wm8994-core.c  --  Device access for Wolfson WM8994
3 *
4 * Copyright 2009 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 modify it
9 *  under  the terms of  the GNU General  Public License as published by the
10 *  Free Software Foundation;  either version 2 of the  License, or (at your
11 *  option) any later version.
12 *
13 */
14
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18#include <linux/i2c.h>
19#include <linux/delay.h>
20#include <linux/mfd/core.h>
21#include <linux/regulator/consumer.h>
22#include <linux/regulator/machine.h>
23
24#include <linux/mfd/wm8994/core.h>
25#include <linux/mfd/wm8994/pdata.h>
26#include <linux/mfd/wm8994/registers.h>
27
28static int wm8994_read(struct wm8994 *wm8994, unsigned short reg,
29		       int bytes, void *dest)
30{
31	int ret, i;
32	u16 *buf = dest;
33
34	BUG_ON(bytes % 2);
35	BUG_ON(bytes <= 0);
36
37	ret = wm8994->read_dev(wm8994, reg, bytes, dest);
38	if (ret < 0)
39		return ret;
40
41	for (i = 0; i < bytes / 2; i++) {
42		buf[i] = be16_to_cpu(buf[i]);
43
44		dev_vdbg(wm8994->dev, "Read %04x from R%d(0x%x)\n",
45			 buf[i], reg + i, reg + i);
46	}
47
48	return 0;
49}
50
51/**
52 * wm8994_reg_read: Read a single WM8994 register.
53 *
54 * @wm8994: Device to read from.
55 * @reg: Register to read.
56 */
57int wm8994_reg_read(struct wm8994 *wm8994, unsigned short reg)
58{
59	unsigned short val;
60	int ret;
61
62	mutex_lock(&wm8994->io_lock);
63
64	ret = wm8994_read(wm8994, reg, 2, &val);
65
66	mutex_unlock(&wm8994->io_lock);
67
68	if (ret < 0)
69		return ret;
70	else
71		return val;
72}
73EXPORT_SYMBOL_GPL(wm8994_reg_read);
74
75/**
76 * wm8994_bulk_read: Read multiple WM8994 registers
77 *
78 * @wm8994: Device to read from
79 * @reg: First register
80 * @count: Number of registers
81 * @buf: Buffer to fill.
82 */
83int wm8994_bulk_read(struct wm8994 *wm8994, unsigned short reg,
84		     int count, u16 *buf)
85{
86	int ret;
87
88	mutex_lock(&wm8994->io_lock);
89
90	ret = wm8994_read(wm8994, reg, count * 2, buf);
91
92	mutex_unlock(&wm8994->io_lock);
93
94	return ret;
95}
96EXPORT_SYMBOL_GPL(wm8994_bulk_read);
97
98static int wm8994_write(struct wm8994 *wm8994, unsigned short reg,
99			int bytes, void *src)
100{
101	u16 *buf = src;
102	int i;
103
104	BUG_ON(bytes % 2);
105	BUG_ON(bytes <= 0);
106
107	for (i = 0; i < bytes / 2; i++) {
108		dev_vdbg(wm8994->dev, "Write %04x to R%d(0x%x)\n",
109			 buf[i], reg + i, reg + i);
110
111		buf[i] = cpu_to_be16(buf[i]);
112	}
113
114	return wm8994->write_dev(wm8994, reg, bytes, src);
115}
116
117/**
118 * wm8994_reg_write: Write a single WM8994 register.
119 *
120 * @wm8994: Device to write to.
121 * @reg: Register to write to.
122 * @val: Value to write.
123 */
124int wm8994_reg_write(struct wm8994 *wm8994, unsigned short reg,
125		     unsigned short val)
126{
127	int ret;
128
129	mutex_lock(&wm8994->io_lock);
130
131	ret = wm8994_write(wm8994, reg, 2, &val);
132
133	mutex_unlock(&wm8994->io_lock);
134
135	return ret;
136}
137EXPORT_SYMBOL_GPL(wm8994_reg_write);
138
139/**
140 * wm8994_set_bits: Set the value of a bitfield in a WM8994 register
141 *
142 * @wm8994: Device to write to.
143 * @reg: Register to write to.
144 * @mask: Mask of bits to set.
145 * @val: Value to set (unshifted)
146 */
147int wm8994_set_bits(struct wm8994 *wm8994, unsigned short reg,
148		    unsigned short mask, unsigned short val)
149{
150	int ret;
151	u16 r;
152
153	mutex_lock(&wm8994->io_lock);
154
155	ret = wm8994_read(wm8994, reg, 2, &r);
156	if (ret < 0)
157		goto out;
158
159	r &= ~mask;
160	r |= val;
161
162	ret = wm8994_write(wm8994, reg, 2, &r);
163
164out:
165	mutex_unlock(&wm8994->io_lock);
166
167	return ret;
168}
169EXPORT_SYMBOL_GPL(wm8994_set_bits);
170
171static struct mfd_cell wm8994_regulator_devs[] = {
172	{ .name = "wm8994-ldo", .id = 1 },
173	{ .name = "wm8994-ldo", .id = 2 },
174};
175
176static struct mfd_cell wm8994_devs[] = {
177	{ .name = "wm8994-codec" },
178	{ .name = "wm8994-gpio" },
179};
180
181/*
182 * Supplies for the main bulk of CODEC; the LDO supplies are ignored
183 * and should be handled via the standard regulator API supply
184 * management.
185 */
186static const char *wm8994_main_supplies[] = {
187	"DBVDD",
188	"DCVDD",
189	"AVDD1",
190	"AVDD2",
191	"CPVDD",
192	"SPKVDD1",
193	"SPKVDD2",
194};
195
196#ifdef CONFIG_PM
197static int wm8994_device_suspend(struct device *dev)
198{
199	struct wm8994 *wm8994 = dev_get_drvdata(dev);
200	int ret;
201
202	/* GPIO configuration state is saved here since we may be configuring
203	 * the GPIO alternate functions even if we're not using the gpiolib
204	 * driver for them.
205	 */
206	ret = wm8994_read(wm8994, WM8994_GPIO_1, WM8994_NUM_GPIO_REGS * 2,
207			  &wm8994->gpio_regs);
208	if (ret < 0)
209		dev_err(dev, "Failed to save GPIO registers: %d\n", ret);
210
211	/* For similar reasons we also stash the regulator states */
212	ret = wm8994_read(wm8994, WM8994_LDO_1, WM8994_NUM_LDO_REGS * 2,
213			  &wm8994->ldo_regs);
214	if (ret < 0)
215		dev_err(dev, "Failed to save LDO registers: %d\n", ret);
216
217	ret = regulator_bulk_disable(ARRAY_SIZE(wm8994_main_supplies),
218				     wm8994->supplies);
219	if (ret != 0) {
220		dev_err(dev, "Failed to disable supplies: %d\n", ret);
221		return ret;
222	}
223
224	return 0;
225}
226
227static int wm8994_device_resume(struct device *dev)
228{
229	struct wm8994 *wm8994 = dev_get_drvdata(dev);
230	int ret;
231
232	ret = regulator_bulk_enable(ARRAY_SIZE(wm8994_main_supplies),
233				    wm8994->supplies);
234	if (ret != 0) {
235		dev_err(dev, "Failed to enable supplies: %d\n", ret);
236		return ret;
237	}
238
239	ret = wm8994_write(wm8994, WM8994_LDO_1, WM8994_NUM_LDO_REGS * 2,
240			   &wm8994->ldo_regs);
241	if (ret < 0)
242		dev_err(dev, "Failed to restore LDO registers: %d\n", ret);
243
244	ret = wm8994_write(wm8994, WM8994_GPIO_1, WM8994_NUM_GPIO_REGS * 2,
245			   &wm8994->gpio_regs);
246	if (ret < 0)
247		dev_err(dev, "Failed to restore GPIO registers: %d\n", ret);
248
249	return 0;
250}
251#endif
252
253#ifdef CONFIG_REGULATOR
254static int wm8994_ldo_in_use(struct wm8994_pdata *pdata, int ldo)
255{
256	struct wm8994_ldo_pdata *ldo_pdata;
257
258	if (!pdata)
259		return 0;
260
261	ldo_pdata = &pdata->ldo[ldo];
262
263	if (!ldo_pdata->init_data)
264		return 0;
265
266	return ldo_pdata->init_data->num_consumer_supplies != 0;
267}
268#else
269static int wm8994_ldo_in_use(struct wm8994_pdata *pdata, int ldo)
270{
271	return 0;
272}
273#endif
274
275/*
276 * Instantiate the generic non-control parts of the device.
277 */
278static int wm8994_device_init(struct wm8994 *wm8994, unsigned long id, int irq)
279{
280	struct wm8994_pdata *pdata = wm8994->dev->platform_data;
281	int ret, i;
282
283	mutex_init(&wm8994->io_lock);
284	dev_set_drvdata(wm8994->dev, wm8994);
285
286	/* Add the on-chip regulators first for bootstrapping */
287	ret = mfd_add_devices(wm8994->dev, -1,
288			      wm8994_regulator_devs,
289			      ARRAY_SIZE(wm8994_regulator_devs),
290			      NULL, 0);
291	if (ret != 0) {
292		dev_err(wm8994->dev, "Failed to add children: %d\n", ret);
293		goto err;
294	}
295
296	wm8994->supplies = kzalloc(sizeof(struct regulator_bulk_data) *
297				   ARRAY_SIZE(wm8994_main_supplies),
298				   GFP_KERNEL);
299	if (!wm8994->supplies)
300		goto err;
301
302	for (i = 0; i < ARRAY_SIZE(wm8994_main_supplies); i++)
303		wm8994->supplies[i].supply = wm8994_main_supplies[i];
304
305	ret = regulator_bulk_get(wm8994->dev, ARRAY_SIZE(wm8994_main_supplies),
306				 wm8994->supplies);
307	if (ret != 0) {
308		dev_err(wm8994->dev, "Failed to get supplies: %d\n", ret);
309		goto err_supplies;
310	}
311
312	ret = regulator_bulk_enable(ARRAY_SIZE(wm8994_main_supplies),
313				    wm8994->supplies);
314	if (ret != 0) {
315		dev_err(wm8994->dev, "Failed to enable supplies: %d\n", ret);
316		goto err_get;
317	}
318
319	ret = wm8994_reg_read(wm8994, WM8994_SOFTWARE_RESET);
320	if (ret < 0) {
321		dev_err(wm8994->dev, "Failed to read ID register\n");
322		goto err_enable;
323	}
324	if (ret != 0x8994) {
325		dev_err(wm8994->dev, "Device is not a WM8994, ID is %x\n",
326			ret);
327		ret = -EINVAL;
328		goto err_enable;
329	}
330
331	ret = wm8994_reg_read(wm8994, WM8994_CHIP_REVISION);
332	if (ret < 0) {
333		dev_err(wm8994->dev, "Failed to read revision register: %d\n",
334			ret);
335		goto err_enable;
336	}
337
338	switch (ret) {
339	case 0:
340	case 1:
341		dev_warn(wm8994->dev, "revision %c not fully supported\n",
342			'A' + ret);
343		break;
344	default:
345		dev_info(wm8994->dev, "revision %c\n", 'A' + ret);
346		break;
347	}
348
349
350	if (pdata) {
351		wm8994->gpio_base = pdata->gpio_base;
352
353		/* GPIO configuration is only applied if it's non-zero */
354		for (i = 0; i < ARRAY_SIZE(pdata->gpio_defaults); i++) {
355			if (pdata->gpio_defaults[i]) {
356				wm8994_set_bits(wm8994, WM8994_GPIO_1 + i,
357						0xffff,
358						pdata->gpio_defaults[i]);
359			}
360		}
361	}
362
363	/* In some system designs where the regulators are not in use,
364	 * we can achieve a small reduction in leakage currents by
365	 * floating LDO outputs.  This bit makes no difference if the
366	 * LDOs are enabled, it only affects cases where the LDOs were
367	 * in operation and are then disabled.
368	 */
369	for (i = 0; i < WM8994_NUM_LDO_REGS; i++) {
370		if (wm8994_ldo_in_use(pdata, i))
371			wm8994_set_bits(wm8994, WM8994_LDO_1 + i,
372					WM8994_LDO1_DISCH, WM8994_LDO1_DISCH);
373		else
374			wm8994_set_bits(wm8994, WM8994_LDO_1 + i,
375					WM8994_LDO1_DISCH, 0);
376	}
377
378	ret = mfd_add_devices(wm8994->dev, -1,
379			      wm8994_devs, ARRAY_SIZE(wm8994_devs),
380			      NULL, 0);
381	if (ret != 0) {
382		dev_err(wm8994->dev, "Failed to add children: %d\n", ret);
383		goto err_enable;
384	}
385
386	return 0;
387
388err_enable:
389	regulator_bulk_disable(ARRAY_SIZE(wm8994_main_supplies),
390			       wm8994->supplies);
391err_get:
392	regulator_bulk_free(ARRAY_SIZE(wm8994_main_supplies), wm8994->supplies);
393err_supplies:
394	kfree(wm8994->supplies);
395err:
396	mfd_remove_devices(wm8994->dev);
397	kfree(wm8994);
398	return ret;
399}
400
401static void wm8994_device_exit(struct wm8994 *wm8994)
402{
403	mfd_remove_devices(wm8994->dev);
404	regulator_bulk_disable(ARRAY_SIZE(wm8994_main_supplies),
405			       wm8994->supplies);
406	regulator_bulk_free(ARRAY_SIZE(wm8994_main_supplies), wm8994->supplies);
407	kfree(wm8994->supplies);
408	kfree(wm8994);
409}
410
411static int wm8994_i2c_read_device(struct wm8994 *wm8994, unsigned short reg,
412				  int bytes, void *dest)
413{
414	struct i2c_client *i2c = wm8994->control_data;
415	int ret;
416	u16 r = cpu_to_be16(reg);
417
418	ret = i2c_master_send(i2c, (unsigned char *)&r, 2);
419	if (ret < 0)
420		return ret;
421	if (ret != 2)
422		return -EIO;
423
424	ret = i2c_master_recv(i2c, dest, bytes);
425	if (ret < 0)
426		return ret;
427	if (ret != bytes)
428		return -EIO;
429	return 0;
430}
431
432/* Currently we allocate the write buffer on the stack; this is OK for
433 * small writes - if we need to do large writes this will need to be
434 * revised.
435 */
436static int wm8994_i2c_write_device(struct wm8994 *wm8994, unsigned short reg,
437				   int bytes, void *src)
438{
439	struct i2c_client *i2c = wm8994->control_data;
440	unsigned char msg[bytes + 2];
441	int ret;
442
443	reg = cpu_to_be16(reg);
444	memcpy(&msg[0], &reg, 2);
445	memcpy(&msg[2], src, bytes);
446
447	ret = i2c_master_send(i2c, msg, bytes + 2);
448	if (ret < 0)
449		return ret;
450	if (ret < bytes + 2)
451		return -EIO;
452
453	return 0;
454}
455
456static int wm8994_i2c_probe(struct i2c_client *i2c,
457			    const struct i2c_device_id *id)
458{
459	struct wm8994 *wm8994;
460
461	wm8994 = kzalloc(sizeof(struct wm8994), GFP_KERNEL);
462	if (wm8994 == NULL) {
463		kfree(i2c);
464		return -ENOMEM;
465	}
466
467	i2c_set_clientdata(i2c, wm8994);
468	wm8994->dev = &i2c->dev;
469	wm8994->control_data = i2c;
470	wm8994->read_dev = wm8994_i2c_read_device;
471	wm8994->write_dev = wm8994_i2c_write_device;
472
473	return wm8994_device_init(wm8994, id->driver_data, i2c->irq);
474}
475
476static int wm8994_i2c_remove(struct i2c_client *i2c)
477{
478	struct wm8994 *wm8994 = i2c_get_clientdata(i2c);
479
480	wm8994_device_exit(wm8994);
481
482	return 0;
483}
484
485#ifdef CONFIG_PM
486static int wm8994_i2c_suspend(struct i2c_client *i2c, pm_message_t state)
487{
488	return wm8994_device_suspend(&i2c->dev);
489}
490
491static int wm8994_i2c_resume(struct i2c_client *i2c)
492{
493	return wm8994_device_resume(&i2c->dev);
494}
495#else
496#define wm8994_i2c_suspend NULL
497#define wm8994_i2c_resume NULL
498#endif
499
500static const struct i2c_device_id wm8994_i2c_id[] = {
501	{ "wm8994", 0 },
502	{ }
503};
504MODULE_DEVICE_TABLE(i2c, wm8994_i2c_id);
505
506static struct i2c_driver wm8994_i2c_driver = {
507	.driver = {
508		   .name = "wm8994",
509		   .owner = THIS_MODULE,
510	},
511	.probe = wm8994_i2c_probe,
512	.remove = wm8994_i2c_remove,
513	.suspend = wm8994_i2c_suspend,
514	.resume = wm8994_i2c_resume,
515	.id_table = wm8994_i2c_id,
516};
517
518static int __init wm8994_i2c_init(void)
519{
520	int ret;
521
522	ret = i2c_add_driver(&wm8994_i2c_driver);
523	if (ret != 0)
524		pr_err("Failed to register wm8994 I2C driver: %d\n", ret);
525
526	return ret;
527}
528module_init(wm8994_i2c_init);
529
530static void __exit wm8994_i2c_exit(void)
531{
532	i2c_del_driver(&wm8994_i2c_driver);
533}
534module_exit(wm8994_i2c_exit);
535
536MODULE_DESCRIPTION("Core support for the WM8994 audio CODEC");
537MODULE_LICENSE("GPL");
538MODULE_AUTHOR("Mark Brown <broonie@opensource.wolfsonmicro.com>");
539