1// SPDX-License-Identifier: GPL-2.0+
2//
3// soc-ac97.c  --  ALSA SoC Audio Layer AC97 support
4//
5// Copyright 2005 Wolfson Microelectronics PLC.
6// Copyright 2005 Openedhand Ltd.
7// Copyright (C) 2010 Slimlogic Ltd.
8// Copyright (C) 2010 Texas Instruments Inc.
9//
10// Author: Liam Girdwood <lrg@slimlogic.co.uk>
11//         with code, comments and ideas from :-
12//         Richard Purdie <richard@openedhand.com>
13
14#include <linux/ctype.h>
15#include <linux/delay.h>
16#include <linux/export.h>
17#include <linux/gpio/consumer.h>
18#include <linux/gpio/driver.h>
19#include <linux/init.h>
20#include <linux/of.h>
21#include <linux/pinctrl/consumer.h>
22#include <linux/slab.h>
23#include <sound/ac97_codec.h>
24#include <sound/soc.h>
25
26struct snd_ac97_reset_cfg {
27	struct pinctrl *pctl;
28	struct pinctrl_state *pstate_reset;
29	struct pinctrl_state *pstate_warm_reset;
30	struct pinctrl_state *pstate_run;
31	struct gpio_desc *reset_gpio;
32	struct gpio_desc *sdata_gpio;
33	struct gpio_desc *sync_gpio;
34};
35
36static struct snd_ac97_bus soc_ac97_bus = {
37	.ops = NULL, /* Gets initialized in snd_soc_set_ac97_ops() */
38};
39
40static void soc_ac97_device_release(struct device *dev)
41{
42	kfree(to_ac97_t(dev));
43}
44
45#ifdef CONFIG_GPIOLIB
46struct snd_ac97_gpio_priv {
47	struct gpio_chip gpio_chip;
48	unsigned int gpios_set;
49	struct snd_soc_component *component;
50};
51
52static inline struct snd_soc_component *gpio_to_component(struct gpio_chip *chip)
53{
54	struct snd_ac97_gpio_priv *gpio_priv = gpiochip_get_data(chip);
55
56	return gpio_priv->component;
57}
58
59static int snd_soc_ac97_gpio_request(struct gpio_chip *chip, unsigned int offset)
60{
61	if (offset >= AC97_NUM_GPIOS)
62		return -EINVAL;
63
64	return 0;
65}
66
67static int snd_soc_ac97_gpio_direction_in(struct gpio_chip *chip,
68					  unsigned int offset)
69{
70	struct snd_soc_component *component = gpio_to_component(chip);
71
72	dev_dbg(component->dev, "set gpio %d to output\n", offset);
73	return snd_soc_component_update_bits(component, AC97_GPIO_CFG,
74				   1 << offset, 1 << offset);
75}
76
77static int snd_soc_ac97_gpio_get(struct gpio_chip *chip, unsigned int offset)
78{
79	struct snd_soc_component *component = gpio_to_component(chip);
80	int ret;
81
82	ret = snd_soc_component_read(component, AC97_GPIO_STATUS);
83
84	dev_dbg(component->dev, "get gpio %d : %d\n", offset,
85		ret & (1 << offset));
86
87	return !!(ret & (1 << offset));
88}
89
90static void snd_soc_ac97_gpio_set(struct gpio_chip *chip, unsigned int offset,
91				  int value)
92{
93	struct snd_ac97_gpio_priv *gpio_priv = gpiochip_get_data(chip);
94	struct snd_soc_component *component = gpio_to_component(chip);
95
96	gpio_priv->gpios_set &= ~(1 << offset);
97	gpio_priv->gpios_set |= (!!value) << offset;
98	snd_soc_component_write(component, AC97_GPIO_STATUS,
99				gpio_priv->gpios_set);
100	dev_dbg(component->dev, "set gpio %d to %d\n", offset, !!value);
101}
102
103static int snd_soc_ac97_gpio_direction_out(struct gpio_chip *chip,
104				     unsigned offset, int value)
105{
106	struct snd_soc_component *component = gpio_to_component(chip);
107
108	dev_dbg(component->dev, "set gpio %d to output\n", offset);
109	snd_soc_ac97_gpio_set(chip, offset, value);
110	return snd_soc_component_update_bits(component, AC97_GPIO_CFG,
111					     1 << offset, 0);
112}
113
114static const struct gpio_chip snd_soc_ac97_gpio_chip = {
115	.label			= "snd_soc_ac97",
116	.owner			= THIS_MODULE,
117	.request		= snd_soc_ac97_gpio_request,
118	.direction_input	= snd_soc_ac97_gpio_direction_in,
119	.get			= snd_soc_ac97_gpio_get,
120	.direction_output	= snd_soc_ac97_gpio_direction_out,
121	.set			= snd_soc_ac97_gpio_set,
122	.can_sleep		= 1,
123};
124
125static int snd_soc_ac97_init_gpio(struct snd_ac97 *ac97,
126				  struct snd_soc_component *component)
127{
128	struct snd_ac97_gpio_priv *gpio_priv;
129	int ret;
130
131	gpio_priv = devm_kzalloc(component->dev, sizeof(*gpio_priv), GFP_KERNEL);
132	if (!gpio_priv)
133		return -ENOMEM;
134	ac97->gpio_priv = gpio_priv;
135	gpio_priv->component = component;
136	gpio_priv->gpio_chip = snd_soc_ac97_gpio_chip;
137	gpio_priv->gpio_chip.ngpio = AC97_NUM_GPIOS;
138	gpio_priv->gpio_chip.parent = component->dev;
139	gpio_priv->gpio_chip.base = -1;
140
141	ret = gpiochip_add_data(&gpio_priv->gpio_chip, gpio_priv);
142	if (ret != 0)
143		dev_err(component->dev, "Failed to add GPIOs: %d\n", ret);
144	return ret;
145}
146
147static void snd_soc_ac97_free_gpio(struct snd_ac97 *ac97)
148{
149	gpiochip_remove(&ac97->gpio_priv->gpio_chip);
150}
151#else
152static int snd_soc_ac97_init_gpio(struct snd_ac97 *ac97,
153				  struct snd_soc_component *component)
154{
155	return 0;
156}
157
158static void snd_soc_ac97_free_gpio(struct snd_ac97 *ac97)
159{
160}
161#endif
162
163/**
164 * snd_soc_alloc_ac97_component() - Allocate new a AC'97 device
165 * @component: The COMPONENT for which to create the AC'97 device
166 *
167 * Allocated a new snd_ac97 device and intializes it, but does not yet register
168 * it. The caller is responsible to either call device_add(&ac97->dev) to
169 * register the device, or to call put_device(&ac97->dev) to free the device.
170 *
171 * Returns: A snd_ac97 device or a PTR_ERR in case of an error.
172 */
173struct snd_ac97 *snd_soc_alloc_ac97_component(struct snd_soc_component *component)
174{
175	struct snd_ac97 *ac97;
176
177	ac97 = kzalloc(sizeof(struct snd_ac97), GFP_KERNEL);
178	if (ac97 == NULL)
179		return ERR_PTR(-ENOMEM);
180
181	ac97->bus = &soc_ac97_bus;
182	ac97->num = 0;
183
184	ac97->dev.bus = &ac97_bus_type;
185	ac97->dev.parent = component->card->dev;
186	ac97->dev.release = soc_ac97_device_release;
187
188	dev_set_name(&ac97->dev, "%d-%d:%s",
189		     component->card->snd_card->number, 0,
190		     component->name);
191
192	device_initialize(&ac97->dev);
193
194	return ac97;
195}
196EXPORT_SYMBOL(snd_soc_alloc_ac97_component);
197
198/**
199 * snd_soc_new_ac97_component - initailise AC97 device
200 * @component: audio component
201 * @id: The expected device ID
202 * @id_mask: Mask that is applied to the device ID before comparing with @id
203 *
204 * Initialises AC97 component resources for use by ad-hoc devices only.
205 *
206 * If @id is not 0 this function will reset the device, then read the ID from
207 * the device and check if it matches the expected ID. If it doesn't match an
208 * error will be returned and device will not be registered.
209 *
210 * Returns: A PTR_ERR() on failure or a valid snd_ac97 struct on success.
211 */
212struct snd_ac97 *snd_soc_new_ac97_component(struct snd_soc_component *component,
213	unsigned int id, unsigned int id_mask)
214{
215	struct snd_ac97 *ac97;
216	int ret;
217
218	ac97 = snd_soc_alloc_ac97_component(component);
219	if (IS_ERR(ac97))
220		return ac97;
221
222	if (id) {
223		ret = snd_ac97_reset(ac97, false, id, id_mask);
224		if (ret < 0) {
225			dev_err(component->dev, "Failed to reset AC97 device: %d\n",
226				ret);
227			goto err_put_device;
228		}
229	}
230
231	ret = device_add(&ac97->dev);
232	if (ret)
233		goto err_put_device;
234
235	ret = snd_soc_ac97_init_gpio(ac97, component);
236	if (ret)
237		goto err_put_device;
238
239	return ac97;
240
241err_put_device:
242	put_device(&ac97->dev);
243	return ERR_PTR(ret);
244}
245EXPORT_SYMBOL_GPL(snd_soc_new_ac97_component);
246
247/**
248 * snd_soc_free_ac97_component - free AC97 component device
249 * @ac97: snd_ac97 device to be freed
250 *
251 * Frees AC97 component device resources.
252 */
253void snd_soc_free_ac97_component(struct snd_ac97 *ac97)
254{
255	snd_soc_ac97_free_gpio(ac97);
256	device_del(&ac97->dev);
257	ac97->bus = NULL;
258	put_device(&ac97->dev);
259}
260EXPORT_SYMBOL_GPL(snd_soc_free_ac97_component);
261
262static struct snd_ac97_reset_cfg snd_ac97_rst_cfg;
263
264static void snd_soc_ac97_warm_reset(struct snd_ac97 *ac97)
265{
266	struct pinctrl *pctl = snd_ac97_rst_cfg.pctl;
267
268	pinctrl_select_state(pctl, snd_ac97_rst_cfg.pstate_warm_reset);
269
270	gpiod_direction_output_raw(snd_ac97_rst_cfg.sync_gpio, 1);
271
272	udelay(10);
273
274	gpiod_direction_output_raw(snd_ac97_rst_cfg.sync_gpio, 0);
275
276	pinctrl_select_state(pctl, snd_ac97_rst_cfg.pstate_run);
277	msleep(2);
278}
279
280static void snd_soc_ac97_reset(struct snd_ac97 *ac97)
281{
282	struct pinctrl *pctl = snd_ac97_rst_cfg.pctl;
283
284	pinctrl_select_state(pctl, snd_ac97_rst_cfg.pstate_reset);
285
286	gpiod_direction_output_raw(snd_ac97_rst_cfg.sync_gpio, 0);
287	gpiod_direction_output_raw(snd_ac97_rst_cfg.sdata_gpio, 0);
288	gpiod_direction_output_raw(snd_ac97_rst_cfg.reset_gpio, 0);
289
290	udelay(10);
291
292	gpiod_direction_output_raw(snd_ac97_rst_cfg.reset_gpio, 1);
293
294	pinctrl_select_state(pctl, snd_ac97_rst_cfg.pstate_run);
295	msleep(2);
296}
297
298static int snd_soc_ac97_parse_pinctl(struct device *dev,
299		struct snd_ac97_reset_cfg *cfg)
300{
301	struct pinctrl *p;
302	struct pinctrl_state *state;
303
304	p = devm_pinctrl_get(dev);
305	if (IS_ERR(p)) {
306		dev_err(dev, "Failed to get pinctrl\n");
307		return PTR_ERR(p);
308	}
309	cfg->pctl = p;
310
311	state = pinctrl_lookup_state(p, "ac97-reset");
312	if (IS_ERR(state)) {
313		dev_err(dev, "Can't find pinctrl state ac97-reset\n");
314		return PTR_ERR(state);
315	}
316	cfg->pstate_reset = state;
317
318	state = pinctrl_lookup_state(p, "ac97-warm-reset");
319	if (IS_ERR(state)) {
320		dev_err(dev, "Can't find pinctrl state ac97-warm-reset\n");
321		return PTR_ERR(state);
322	}
323	cfg->pstate_warm_reset = state;
324
325	state = pinctrl_lookup_state(p, "ac97-running");
326	if (IS_ERR(state)) {
327		dev_err(dev, "Can't find pinctrl state ac97-running\n");
328		return PTR_ERR(state);
329	}
330	cfg->pstate_run = state;
331
332	cfg->sync_gpio = devm_gpiod_get_index(dev, "ac97", 0, GPIOD_ASIS);
333	if (IS_ERR(cfg->sync_gpio))
334		return dev_err_probe(dev, PTR_ERR(cfg->sync_gpio), "Can't find ac97-sync gpio\n");
335	gpiod_set_consumer_name(cfg->sync_gpio, "AC97 link sync");
336
337	cfg->sdata_gpio = devm_gpiod_get_index(dev, "ac97", 1, GPIOD_ASIS);
338	if (IS_ERR(cfg->sdata_gpio))
339		return dev_err_probe(dev, PTR_ERR(cfg->sdata_gpio), "Can't find ac97-sdata gpio\n");
340	gpiod_set_consumer_name(cfg->sdata_gpio, "AC97 link sdata");
341
342	cfg->reset_gpio = devm_gpiod_get_index(dev, "ac97", 2, GPIOD_ASIS);
343	if (IS_ERR(cfg->reset_gpio))
344		return dev_err_probe(dev, PTR_ERR(cfg->reset_gpio), "Can't find ac97-reset gpio\n");
345	gpiod_set_consumer_name(cfg->reset_gpio, "AC97 link reset");
346
347	return 0;
348}
349
350struct snd_ac97_bus_ops *soc_ac97_ops;
351EXPORT_SYMBOL_GPL(soc_ac97_ops);
352
353int snd_soc_set_ac97_ops(struct snd_ac97_bus_ops *ops)
354{
355	if (ops == soc_ac97_ops)
356		return 0;
357
358	if (soc_ac97_ops && ops)
359		return -EBUSY;
360
361	soc_ac97_ops = ops;
362	soc_ac97_bus.ops = ops;
363
364	return 0;
365}
366EXPORT_SYMBOL_GPL(snd_soc_set_ac97_ops);
367
368/**
369 * snd_soc_set_ac97_ops_of_reset - Set ac97 ops with generic ac97 reset functions
370 * @ops: bus ops
371 * @pdev: platform device
372 *
373 * This function sets the reset and warm_reset properties of ops and parses
374 * the device node of pdev to get pinctrl states and gpio numbers to use.
375 */
376int snd_soc_set_ac97_ops_of_reset(struct snd_ac97_bus_ops *ops,
377		struct platform_device *pdev)
378{
379	struct device *dev = &pdev->dev;
380	struct snd_ac97_reset_cfg cfg;
381	int ret;
382
383	ret = snd_soc_ac97_parse_pinctl(dev, &cfg);
384	if (ret)
385		return ret;
386
387	ret = snd_soc_set_ac97_ops(ops);
388	if (ret)
389		return ret;
390
391	ops->warm_reset = snd_soc_ac97_warm_reset;
392	ops->reset = snd_soc_ac97_reset;
393
394	snd_ac97_rst_cfg = cfg;
395	return 0;
396}
397EXPORT_SYMBOL_GPL(snd_soc_set_ac97_ops_of_reset);
398