drivers/misc/atmel-ssc.c

   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
  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
  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 *
 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
 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
 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
 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
 185 static inline void ssc_sound_dai_remove(struct ssc_device *ssc)
 186 {
 187 }
 188 #endif
 189
 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) {
 236                 dev_dbg(&pdev->dev, "could not get irq\n");
 237                 return -ENXIO;
 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
 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 Egtvedt <hcegtvedt@atmel.com>");
 280 MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
 281 MODULE_LICENSE("GPL");
 282 MODULE_ALIAS("platform:ssc");