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 */
23 static DEFINE_MUTEX(user_lock);
24 static LIST_HEAD(ssc_list);
25
ssc_request(unsigned int ssc_num)26 struct 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 }
64 EXPORT_SYMBOL(ssc_request);
65
ssc_free(struct ssc_device * ssc)66 void 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 }
82 EXPORT_SYMBOL(ssc_free);
83
84 static struct atmel_ssc_platform_data at91rm9200_config = {
85 .use_dma = 0,
86 .has_fslen_ext = 0,
87 };
88
89 static struct atmel_ssc_platform_data at91sam9rl_config = {
90 .use_dma = 0,
91 .has_fslen_ext = 1,
92 };
93
94 static struct atmel_ssc_platform_data at91sam9g45_config = {
95 .use_dma = 1,
96 .has_fslen_ext = 1,
97 };
98
99 static 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
115 static 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 };
129 MODULE_DEVICE_TABLE(of, atmel_ssc_dt_ids);
130 #endif
131
132 static inline const struct atmel_ssc_platform_data *
atmel_ssc_get_driver_data(struct platform_device * pdev)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
ssc_sound_dai_probe(struct ssc_device * ssc)148 static 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
ssc_sound_dai_remove(struct ssc_device * ssc)169 static 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
ssc_sound_dai_probe(struct ssc_device * ssc)177 static 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
ssc_sound_dai_remove(struct ssc_device * ssc)185 static inline void ssc_sound_dai_remove(struct ssc_device *ssc)
186 {
187 }
188 #endif
189
ssc_probe(struct platform_device * pdev)190 static 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
ssc_remove(struct platform_device * pdev)255 static 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
268 static 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 };
277 module_platform_driver(ssc_driver);
278
279 MODULE_AUTHOR("Hans-Christian Noren Egtvedt <egtvedt@samfundet.no>");
280 MODULE_DESCRIPTION("SSC driver for Atmel AT91");
281 MODULE_LICENSE("GPL");
282 MODULE_ALIAS("platform:ssc");
283