1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Atmel SSC driver
4 *
5 * Copyright (C) 2007 Atmel Corporation
6 */
7
8#include <linux/platform_device.h>
9#include <linux/list.h>
10#include <linux/clk.h>
11#include <linux/err.h>
12#include <linux/io.h>
13#include <linux/mutex.h>
14#include <linux/atmel-ssc.h>
15#include <linux/slab.h>
16#include <linux/module.h>
17
18#include <linux/of.h>
19
20#include "../../sound/soc/atmel/atmel_ssc_dai.h"
21
22/* Serialize access to ssc_list and user count */
23static DEFINE_MUTEX(user_lock);
24static LIST_HEAD(ssc_list);
25
26struct ssc_device *ssc_request(unsigned int ssc_num)
27{
28	int ssc_valid = 0;
29	struct ssc_device *ssc;
30
31	mutex_lock(&user_lock);
32	list_for_each_entry(ssc, &ssc_list, list) {
33		if (ssc->pdev->dev.of_node) {
34			if (of_alias_get_id(ssc->pdev->dev.of_node, "ssc")
35				== ssc_num) {
36				ssc->pdev->id = ssc_num;
37				ssc_valid = 1;
38				break;
39			}
40		} else if (ssc->pdev->id == ssc_num) {
41			ssc_valid = 1;
42			break;
43		}
44	}
45
46	if (!ssc_valid) {
47		mutex_unlock(&user_lock);
48		pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
49		return ERR_PTR(-ENODEV);
50	}
51
52	if (ssc->user) {
53		mutex_unlock(&user_lock);
54		dev_dbg(&ssc->pdev->dev, "module busy\n");
55		return ERR_PTR(-EBUSY);
56	}
57	ssc->user++;
58	mutex_unlock(&user_lock);
59
60	clk_prepare(ssc->clk);
61
62	return ssc;
63}
64EXPORT_SYMBOL(ssc_request);
65
66void ssc_free(struct ssc_device *ssc)
67{
68	bool disable_clk = true;
69
70	mutex_lock(&user_lock);
71	if (ssc->user)
72		ssc->user--;
73	else {
74		disable_clk = false;
75		dev_dbg(&ssc->pdev->dev, "device already free\n");
76	}
77	mutex_unlock(&user_lock);
78
79	if (disable_clk)
80		clk_unprepare(ssc->clk);
81}
82EXPORT_SYMBOL(ssc_free);
83
84static struct atmel_ssc_platform_data at91rm9200_config = {
85	.use_dma = 0,
86	.has_fslen_ext = 0,
87};
88
89static struct atmel_ssc_platform_data at91sam9rl_config = {
90	.use_dma = 0,
91	.has_fslen_ext = 1,
92};
93
94static struct atmel_ssc_platform_data at91sam9g45_config = {
95	.use_dma = 1,
96	.has_fslen_ext = 1,
97};
98
99static const struct platform_device_id atmel_ssc_devtypes[] = {
100	{
101		.name = "at91rm9200_ssc",
102		.driver_data = (unsigned long) &at91rm9200_config,
103	}, {
104		.name = "at91sam9rl_ssc",
105		.driver_data = (unsigned long) &at91sam9rl_config,
106	}, {
107		.name = "at91sam9g45_ssc",
108		.driver_data = (unsigned long) &at91sam9g45_config,
109	}, {
110		/* sentinel */
111	}
112};
113
114#ifdef CONFIG_OF
115static const struct of_device_id atmel_ssc_dt_ids[] = {
116	{
117		.compatible = "atmel,at91rm9200-ssc",
118		.data = &at91rm9200_config,
119	}, {
120		.compatible = "atmel,at91sam9rl-ssc",
121		.data = &at91sam9rl_config,
122	}, {
123		.compatible = "atmel,at91sam9g45-ssc",
124		.data = &at91sam9g45_config,
125	}, {
126		/* sentinel */
127	}
128};
129MODULE_DEVICE_TABLE(of, atmel_ssc_dt_ids);
130#endif
131
132static inline const struct atmel_ssc_platform_data *
133	atmel_ssc_get_driver_data(struct platform_device *pdev)
134{
135	if (pdev->dev.of_node) {
136		const struct of_device_id *match;
137		match = of_match_node(atmel_ssc_dt_ids, pdev->dev.of_node);
138		if (match == NULL)
139			return NULL;
140		return match->data;
141	}
142
143	return (struct atmel_ssc_platform_data *)
144		platform_get_device_id(pdev)->driver_data;
145}
146
147#ifdef CONFIG_SND_ATMEL_SOC_SSC
148static int ssc_sound_dai_probe(struct ssc_device *ssc)
149{
150	struct device_node *np = ssc->pdev->dev.of_node;
151	int ret;
152	int id;
153
154	ssc->sound_dai = false;
155
156	if (!of_property_read_bool(np, "#sound-dai-cells"))
157		return 0;
158
159	id = of_alias_get_id(np, "ssc");
160	if (id < 0)
161		return id;
162
163	ret = atmel_ssc_set_audio(id);
164	ssc->sound_dai = !ret;
165
166	return ret;
167}
168
169static void ssc_sound_dai_remove(struct ssc_device *ssc)
170{
171	if (!ssc->sound_dai)
172		return;
173
174	atmel_ssc_put_audio(of_alias_get_id(ssc->pdev->dev.of_node, "ssc"));
175}
176#else
177static inline int ssc_sound_dai_probe(struct ssc_device *ssc)
178{
179	if (of_property_read_bool(ssc->pdev->dev.of_node, "#sound-dai-cells"))
180		return -ENOTSUPP;
181
182	return 0;
183}
184
185static inline void ssc_sound_dai_remove(struct ssc_device *ssc)
186{
187}
188#endif
189
190static int ssc_probe(struct platform_device *pdev)
191{
192	struct resource *regs;
193	struct ssc_device *ssc;
194	const struct atmel_ssc_platform_data *plat_dat;
195
196	ssc = devm_kzalloc(&pdev->dev, sizeof(struct ssc_device), GFP_KERNEL);
197	if (!ssc) {
198		dev_dbg(&pdev->dev, "out of memory\n");
199		return -ENOMEM;
200	}
201
202	ssc->pdev = pdev;
203
204	plat_dat = atmel_ssc_get_driver_data(pdev);
205	if (!plat_dat)
206		return -ENODEV;
207	ssc->pdata = (struct atmel_ssc_platform_data *)plat_dat;
208
209	if (pdev->dev.of_node) {
210		struct device_node *np = pdev->dev.of_node;
211		ssc->clk_from_rk_pin =
212			of_property_read_bool(np, "atmel,clk-from-rk-pin");
213	}
214
215	regs = platform_get_resource(pdev, IORESOURCE_MEM, 0);
216	ssc->regs = devm_ioremap_resource(&pdev->dev, regs);
217	if (IS_ERR(ssc->regs))
218		return PTR_ERR(ssc->regs);
219
220	ssc->phybase = regs->start;
221
222	ssc->clk = devm_clk_get(&pdev->dev, "pclk");
223	if (IS_ERR(ssc->clk)) {
224		dev_dbg(&pdev->dev, "no pclk clock defined\n");
225		return -ENXIO;
226	}
227
228	/* disable all interrupts */
229	clk_prepare_enable(ssc->clk);
230	ssc_writel(ssc->regs, IDR, -1);
231	ssc_readl(ssc->regs, SR);
232	clk_disable_unprepare(ssc->clk);
233
234	ssc->irq = platform_get_irq(pdev, 0);
235	if (ssc->irq < 0) {
236		dev_dbg(&pdev->dev, "could not get irq\n");
237		return ssc->irq;
238	}
239
240	mutex_lock(&user_lock);
241	list_add_tail(&ssc->list, &ssc_list);
242	mutex_unlock(&user_lock);
243
244	platform_set_drvdata(pdev, ssc);
245
246	dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n",
247			ssc->regs, ssc->irq);
248
249	if (ssc_sound_dai_probe(ssc))
250		dev_err(&pdev->dev, "failed to auto-setup ssc for audio\n");
251
252	return 0;
253}
254
255static int ssc_remove(struct platform_device *pdev)
256{
257	struct ssc_device *ssc = platform_get_drvdata(pdev);
258
259	ssc_sound_dai_remove(ssc);
260
261	mutex_lock(&user_lock);
262	list_del(&ssc->list);
263	mutex_unlock(&user_lock);
264
265	return 0;
266}
267
268static struct platform_driver ssc_driver = {
269	.driver		= {
270		.name		= "ssc",
271		.of_match_table	= of_match_ptr(atmel_ssc_dt_ids),
272	},
273	.id_table	= atmel_ssc_devtypes,
274	.probe		= ssc_probe,
275	.remove		= ssc_remove,
276};
277module_platform_driver(ssc_driver);
278
279MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
280MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
281MODULE_LICENSE("GPL");
282MODULE_ALIAS("platform:ssc");
283