linux/drivers/misc/atmel-ssc.c
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   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(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}
  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(&user_lock);
  78
  79        if (disable_clk)
  80                clk_unprepare(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(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
 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, "#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
 169static 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
 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(&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
 255static 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
 268static 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};
 277module_platform_driver(ssc_driver);
 278
 279MODULE_AUTHOR("Hans-Christian Egtvedt <hcegtvedt@atmel.com>");
 280MODULE_DESCRIPTION("SSC driver for Atmel AVR32 and AT91");
 281MODULE_LICENSE("GPL");
 282MODULE_ALIAS("platform:ssc");
 283