sound/soc/adi/axi-spdif.c

   1 /*
   2  * Copyright (C) 2012-2013, Analog Devices Inc.
   3  * Author: Lars-Peter Clausen <lars@metafoo.de>
   4  *
   5  * Licensed under the GPL-2.
   6  */
   7
   8 #include <linux/init.h>
   9 #include <linux/kernel.h>
  10 #include <linux/module.h>
  11 #include <linux/platform_device.h>
  12 #include <linux/slab.h>
  13 #include <linux/of.h>
  14 #include <linux/clk.h>
  15 #include <linux/regmap.h>
  16
  17 #include <sound/core.h>
  18 #include <sound/pcm.h>
  19 #include <sound/pcm_params.h>
  20 #include <sound/soc.h>
  21 #include <sound/initval.h>
  22 #include <sound/dmaengine_pcm.h>
  23
  24 #define AXI_SPDIF_REG_CTRL      0x0
  25 #define AXI_SPDIF_REG_STAT      0x4
  26 #define AXI_SPDIF_REG_TX_FIFO   0xc
  27
  28 #define AXI_SPDIF_CTRL_TXDATA BIT(1)
  29 #define AXI_SPDIF_CTRL_TXEN BIT(0)
  30 #define AXI_SPDIF_CTRL_CLKDIV_OFFSET 8
  31 #define AXI_SPDIF_CTRL_CLKDIV_MASK (0xff << 8)
  32
  33 #define AXI_SPDIF_FREQ_44100    (0x0 << 6)
  34 #define AXI_SPDIF_FREQ_48000    (0x1 << 6)
  35 #define AXI_SPDIF_FREQ_32000    (0x2 << 6)
  36 #define AXI_SPDIF_FREQ_NA       (0x3 << 6)
  37
  38 struct axi_spdif {
  39         struct regmap *regmap;
  40         struct clk *clk;
  41         struct clk *clk_ref;
  42
  43         struct snd_dmaengine_dai_dma_data dma_data;
  44
  45         struct snd_ratnum ratnum;
  46         struct snd_pcm_hw_constraint_ratnums rate_constraints;
  47 };
  48
  49 static int axi_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
  50         struct snd_soc_dai *dai)
  51 {
  52         struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
  53         unsigned int val;
  54
  55         switch (cmd) {
  56         case SNDRV_PCM_TRIGGER_START:
  57         case SNDRV_PCM_TRIGGER_RESUME:
  58         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  59                 val = AXI_SPDIF_CTRL_TXDATA;
  60                 break;
  61         case SNDRV_PCM_TRIGGER_STOP:
  62         case SNDRV_PCM_TRIGGER_SUSPEND:
  63         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  64                 val = 0;
  65                 break;
  66         default:
  67                 return -EINVAL;
  68         }
  69
  70         regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
  71                 AXI_SPDIF_CTRL_TXDATA, val);
  72
  73         return 0;
  74 }
  75
  76 static int axi_spdif_hw_params(struct snd_pcm_substream *substream,
  77         struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
  78 {
  79         struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
  80         unsigned int rate = params_rate(params);
  81         unsigned int clkdiv, stat;
  82
  83         switch (params_rate(params)) {
  84         case 32000:
  85                 stat = AXI_SPDIF_FREQ_32000;
  86                 break;
  87         case 44100:
  88                 stat = AXI_SPDIF_FREQ_44100;
  89                 break;
  90         case 48000:
  91                 stat = AXI_SPDIF_FREQ_48000;
  92                 break;
  93         default:
  94                 stat = AXI_SPDIF_FREQ_NA;
  95                 break;
  96         }
  97
  98         clkdiv = DIV_ROUND_CLOSEST(clk_get_rate(spdif->clk_ref),
  99                         rate * 64 * 2) - 1;
 100         clkdiv <<= AXI_SPDIF_CTRL_CLKDIV_OFFSET;
 101
 102         regmap_write(spdif->regmap, AXI_SPDIF_REG_STAT, stat);
 103         regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
 104                 AXI_SPDIF_CTRL_CLKDIV_MASK, clkdiv);
 105
 106         return 0;
 107 }
 108
 109 static int axi_spdif_dai_probe(struct snd_soc_dai *dai)
 110 {
 111         struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
 112
 113         snd_soc_dai_init_dma_data(dai, &spdif->dma_data, NULL);
 114
 115         return 0;
 116 }
 117
 118 static int axi_spdif_startup(struct snd_pcm_substream *substream,
 119         struct snd_soc_dai *dai)
 120 {
 121         struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
 122         int ret;
 123
 124         ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0,
 125                            SNDRV_PCM_HW_PARAM_RATE,
 126                            &spdif->rate_constraints);
 127         if (ret)
 128                 return ret;
 129
 130         ret = clk_prepare_enable(spdif->clk_ref);
 131         if (ret)
 132                 return ret;
 133
 134         regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
 135                 AXI_SPDIF_CTRL_TXEN, AXI_SPDIF_CTRL_TXEN);
 136
 137         return 0;
 138 }
 139
 140 static void axi_spdif_shutdown(struct snd_pcm_substream *substream,
 141         struct snd_soc_dai *dai)
 142 {
 143         struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
 144
 145         regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
 146                 AXI_SPDIF_CTRL_TXEN, 0);
 147
 148         clk_disable_unprepare(spdif->clk_ref);
 149 }
 150
 151 static const struct snd_soc_dai_ops axi_spdif_dai_ops = {
 152         .startup = axi_spdif_startup,
 153         .shutdown = axi_spdif_shutdown,
 154         .trigger = axi_spdif_trigger,
 155         .hw_params = axi_spdif_hw_params,
 156 };
 157
 158 static struct snd_soc_dai_driver axi_spdif_dai = {
 159         .probe = axi_spdif_dai_probe,
 160         .playback = {
 161                 .channels_min = 2,
 162                 .channels_max = 2,
 163                 .rates = SNDRV_PCM_RATE_KNOT,
 164                 .formats = SNDRV_PCM_FMTBIT_S16_LE,
 165         },
 166         .ops = &axi_spdif_dai_ops,
 167 };
 168
 169 static const struct snd_soc_component_driver axi_spdif_component = {
 170         .name = "axi-spdif",
 171 };
 172
 173 static const struct regmap_config axi_spdif_regmap_config = {
 174         .reg_bits = 32,
 175         .reg_stride = 4,
 176         .val_bits = 32,
 177         .max_register = AXI_SPDIF_REG_STAT,
 178 };
 179
 180 static int axi_spdif_probe(struct platform_device *pdev)
 181 {
 182         struct axi_spdif *spdif;
 183         struct resource *res;
 184         void __iomem *base;
 185         int ret;
 186
 187         spdif = devm_kzalloc(&pdev->dev, sizeof(*spdif), GFP_KERNEL);
 188         if (!spdif)
 189                 return -ENOMEM;
 190
 191         platform_set_drvdata(pdev, spdif);
 192
 193         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 194         base = devm_ioremap_resource(&pdev->dev, res);
 195         if (IS_ERR(base))
 196                 return PTR_ERR(base);
 197
 198         spdif->regmap = devm_regmap_init_mmio(&pdev->dev, base,
 199                                             &axi_spdif_regmap_config);
 200         if (IS_ERR(spdif->regmap))
 201                 return PTR_ERR(spdif->regmap);
 202
 203         spdif->clk = devm_clk_get(&pdev->dev, "axi");
 204         if (IS_ERR(spdif->clk))
 205                 return PTR_ERR(spdif->clk);
 206
 207         spdif->clk_ref = devm_clk_get(&pdev->dev, "ref");
 208         if (IS_ERR(spdif->clk_ref))
 209                 return PTR_ERR(spdif->clk_ref);
 210
 211         ret = clk_prepare_enable(spdif->clk);
 212         if (ret)
 213                 return ret;
 214
 215         spdif->dma_data.addr = res->start + AXI_SPDIF_REG_TX_FIFO;
 216         spdif->dma_data.addr_width = 4;
 217         spdif->dma_data.maxburst = 1;
 218
 219         spdif->ratnum.num = clk_get_rate(spdif->clk_ref) / 128;
 220         spdif->ratnum.den_step = 1;
 221         spdif->ratnum.den_min = 1;
 222         spdif->ratnum.den_max = 64;
 223
 224         spdif->rate_constraints.rats = &spdif->ratnum;
 225         spdif->rate_constraints.nrats = 1;
 226
 227         ret = devm_snd_soc_register_component(&pdev->dev, &axi_spdif_component,
 228                                          &axi_spdif_dai, 1);
 229         if (ret)
 230                 goto err_clk_disable;
 231
 232         ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
 233         if (ret)
 234                 goto err_clk_disable;
 235
 236         return 0;
 237
 238 err_clk_disable:
 239         clk_disable_unprepare(spdif->clk);
 240         return ret;
 241 }
 242
 243 static int axi_spdif_dev_remove(struct platform_device *pdev)
 244 {
 245         struct axi_spdif *spdif = platform_get_drvdata(pdev);
 246
 247         clk_disable_unprepare(spdif->clk);
 248
 249         return 0;
 250 }
 251
 252 static const struct of_device_id axi_spdif_of_match[] = {
 253         { .compatible = "adi,axi-spdif-tx-1.00.a", },
 254         {},
 255 };
 256 MODULE_DEVICE_TABLE(of, axi_spdif_of_match);
 257
 258 static struct platform_driver axi_spdif_driver = {
 259         .driver = {
 260                 .name = "axi-spdif",
 261                 .of_match_table = axi_spdif_of_match,
 262         },
 263         .probe = axi_spdif_probe,
 264         .remove = axi_spdif_dev_remove,
 265 };
 266 module_platform_driver(axi_spdif_driver);
 267
 268 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 269 MODULE_DESCRIPTION("AXI SPDIF driver");
 270 MODULE_LICENSE("GPL");