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(np: ssc->pdev->dev.of_node, stem: "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(lock: &user_lock);
48 pr_err("ssc: ssc%d platform device is missing\n", ssc_num);
49 return ERR_PTR(error: -ENODEV);
50 }
51
52 if (ssc->user) {
53 mutex_unlock(lock: &user_lock);
54 dev_dbg(&ssc->pdev->dev, "module busy\n");
55 return ERR_PTR(error: -EBUSY);
56 }
57 ssc->user++;
58 mutex_unlock(lock: &user_lock);
59
60 clk_prepare(clk: 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(lock: &user_lock);
78
79 if (disable_clk)
80 clk_unprepare(clk: 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(matches: atmel_ssc_dt_ids, node: 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, propname: "#sound-dai-cells"))
157 return 0;
158
159 id = of_alias_get_id(np, stem: "ssc");
160 if (id < 0)
161 return id;
162
163 ret = atmel_ssc_set_audio(ssc_id: 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(ssc_id: of_alias_get_id(np: ssc->pdev->dev.of_node, stem: "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(dev: &pdev->dev, size: 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, propname: "atmel,clk-from-rk-pin");
213 }
214
215 ssc->regs = devm_platform_get_and_ioremap_resource(pdev, index: 0, res: &regs);
216 if (IS_ERR(ptr: ssc->regs))
217 return PTR_ERR(ptr: ssc->regs);
218
219 ssc->phybase = regs->start;
220
221 ssc->clk = devm_clk_get(dev: &pdev->dev, id: "pclk");
222 if (IS_ERR(ptr: ssc->clk)) {
223 dev_dbg(&pdev->dev, "no pclk clock defined\n");
224 return -ENXIO;
225 }
226
227 /* disable all interrupts */
228 clk_prepare_enable(clk: ssc->clk);
229 ssc_writel(ssc->regs, IDR, -1);
230 ssc_readl(ssc->regs, SR);
231 clk_disable_unprepare(clk: ssc->clk);
232
233 ssc->irq = platform_get_irq(pdev, 0);
234 if (ssc->irq < 0) {
235 dev_dbg(&pdev->dev, "could not get irq\n");
236 return ssc->irq;
237 }
238
239 mutex_lock(&user_lock);
240 list_add_tail(new: &ssc->list, head: &ssc_list);
241 mutex_unlock(lock: &user_lock);
242
243 platform_set_drvdata(pdev, data: ssc);
244
245 dev_info(&pdev->dev, "Atmel SSC device at 0x%p (irq %d)\n",
246 ssc->regs, ssc->irq);
247
248 if (ssc_sound_dai_probe(ssc))
249 dev_err(&pdev->dev, "failed to auto-setup ssc for audio\n");
250
251 return 0;
252}
253
254static int ssc_remove(struct platform_device *pdev)
255{
256 struct ssc_device *ssc = platform_get_drvdata(pdev);
257
258 ssc_sound_dai_remove(ssc);
259
260 mutex_lock(&user_lock);
261 list_del(entry: &ssc->list);
262 mutex_unlock(lock: &user_lock);
263
264 return 0;
265}
266
267static struct platform_driver ssc_driver = {
268 .driver = {
269 .name = "ssc",
270 .of_match_table = of_match_ptr(atmel_ssc_dt_ids),
271 },
272 .id_table = atmel_ssc_devtypes,
273 .probe = ssc_probe,
274 .remove = ssc_remove,
275};
276module_platform_driver(ssc_driver);
277
278MODULE_AUTHOR("Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>");
279MODULE_DESCRIPTION("SSC driver for Atmel AT91");
280MODULE_LICENSE("GPL");
281MODULE_ALIAS("platform:ssc");
282

source code of linux/drivers/misc/atmel-ssc.c