linux/drivers/misc/atmel-ssc.c
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   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 */
  26static DEFINE_SPINLOCK(user_lock);
  27static LIST_HEAD(ssc_list);
  28
  29struct 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}
  67EXPORT_SYMBOL(ssc_request);
  68
  69void 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}
  85EXPORT_SYMBOL(ssc_free);
  86
  87static struct atmel_ssc_platform_data at91rm9200_config = {
  88        .use_dma = 0,
  89        .has_fslen_ext = 0,
  90};
  91
  92static struct atmel_ssc_platform_data at91sam9rl_config = {
  93        .use_dma = 0,
  94        .has_fslen_ext = 1,
  95};
  96
  97static struct atmel_ssc_platform_data at91sam9g45_config = {
  98        .use_dma = 1,
  99        .has_fslen_ext = 1,
 100};
 101
 102static 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
 118static 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};
 132MODULE_DEVICE_TABLE(of, atmel_ssc_dt_ids);
 133#endif
 134
 135static 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
 151static 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
 172static 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
 180static 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
 188static inline void ssc_sound_dai_remove(struct ssc_device *ssc)
 189{
 190}
 191#endif
 192
 193static 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
 258static 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
 271static 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};
 280module_platform_driver(ssc_driver);
 281
 282MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
 283MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
 284MODULE_LICENSE("GPL");
 285MODULE_ALIAS("platform:ssc");
 286