drivers/misc/atmel-ssc.c

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