sound/soc/adi/axi-i2s.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/clk.h>
   9 #include <linux/init.h>
  10 #include <linux/kernel.h>
  11 #include <linux/module.h>
  12 #include <linux/of.h>
  13 #include <linux/platform_device.h>
  14 #include <linux/regmap.h>
  15 #include <linux/slab.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/dmaengine_pcm.h>
  22
  23 #define AXI_I2S_REG_RESET       0x00
  24 #define AXI_I2S_REG_CTRL        0x04
  25 #define AXI_I2S_REG_CLK_CTRL    0x08
  26 #define AXI_I2S_REG_STATUS      0x10
  27
  28 #define AXI_I2S_REG_RX_FIFO     0x28
  29 #define AXI_I2S_REG_TX_FIFO     0x2C
  30
  31 #define AXI_I2S_RESET_GLOBAL    BIT(0)
  32 #define AXI_I2S_RESET_TX_FIFO   BIT(1)
  33 #define AXI_I2S_RESET_RX_FIFO   BIT(2)
  34
  35 #define AXI_I2S_CTRL_TX_EN      BIT(0)
  36 #define AXI_I2S_CTRL_RX_EN      BIT(1)
  37
  38 /* The frame size is configurable, but for now we always set it 64 bit */
  39 #define AXI_I2S_BITS_PER_FRAME 64
  40
  41 struct axi_i2s {
  42         struct regmap *regmap;
  43         struct clk *clk;
  44         struct clk *clk_ref;
  45
  46         struct snd_soc_dai_driver dai_driver;
  47
  48         struct snd_dmaengine_dai_dma_data capture_dma_data;
  49         struct snd_dmaengine_dai_dma_data playback_dma_data;
  50
  51         struct snd_ratnum ratnum;
  52         struct snd_pcm_hw_constraint_ratnums rate_constraints;
  53 };
  54
  55 static int axi_i2s_trigger(struct snd_pcm_substream *substream, int cmd,
  56         struct snd_soc_dai *dai)
  57 {
  58         struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
  59         unsigned int mask, val;
  60
  61         if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
  62                 mask = AXI_I2S_CTRL_RX_EN;
  63         else
  64                 mask = AXI_I2S_CTRL_TX_EN;
  65
  66         switch (cmd) {
  67         case SNDRV_PCM_TRIGGER_START:
  68         case SNDRV_PCM_TRIGGER_RESUME:
  69         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
  70                 val = mask;
  71                 break;
  72         case SNDRV_PCM_TRIGGER_STOP:
  73         case SNDRV_PCM_TRIGGER_SUSPEND:
  74         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
  75                 val = 0;
  76                 break;
  77         default:
  78                 return -EINVAL;
  79         }
  80
  81         regmap_update_bits(i2s->regmap, AXI_I2S_REG_CTRL, mask, val);
  82
  83         return 0;
  84 }
  85
  86 static int axi_i2s_hw_params(struct snd_pcm_substream *substream,
  87         struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
  88 {
  89         struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
  90         unsigned int bclk_div, word_size;
  91         unsigned int bclk_rate;
  92
  93         bclk_rate = params_rate(params) * AXI_I2S_BITS_PER_FRAME;
  94
  95         word_size = AXI_I2S_BITS_PER_FRAME / 2 - 1;
  96         bclk_div = DIV_ROUND_UP(clk_get_rate(i2s->clk_ref), bclk_rate) / 2 - 1;
  97
  98         regmap_write(i2s->regmap, AXI_I2S_REG_CLK_CTRL, (word_size << 16) |
  99                 bclk_div);
 100
 101         return 0;
 102 }
 103
 104 static int axi_i2s_startup(struct snd_pcm_substream *substream,
 105         struct snd_soc_dai *dai)
 106 {
 107         struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
 108         uint32_t mask;
 109         int ret;
 110
 111         if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
 112                 mask = AXI_I2S_RESET_RX_FIFO;
 113         else
 114                 mask = AXI_I2S_RESET_TX_FIFO;
 115
 116         regmap_write(i2s->regmap, AXI_I2S_REG_RESET, mask);
 117
 118         ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0,
 119                            SNDRV_PCM_HW_PARAM_RATE,
 120                            &i2s->rate_constraints);
 121         if (ret)
 122                 return ret;
 123
 124         return clk_prepare_enable(i2s->clk_ref);
 125 }
 126
 127 static void axi_i2s_shutdown(struct snd_pcm_substream *substream,
 128         struct snd_soc_dai *dai)
 129 {
 130         struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
 131
 132         clk_disable_unprepare(i2s->clk_ref);
 133 }
 134
 135 static int axi_i2s_dai_probe(struct snd_soc_dai *dai)
 136 {
 137         struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai);
 138
 139         snd_soc_dai_init_dma_data(dai, &i2s->playback_dma_data,
 140                 &i2s->capture_dma_data);
 141
 142         return 0;
 143 }
 144
 145 static const struct snd_soc_dai_ops axi_i2s_dai_ops = {
 146         .startup = axi_i2s_startup,
 147         .shutdown = axi_i2s_shutdown,
 148         .trigger = axi_i2s_trigger,
 149         .hw_params = axi_i2s_hw_params,
 150 };
 151
 152 static struct snd_soc_dai_driver axi_i2s_dai = {
 153         .probe = axi_i2s_dai_probe,
 154         .playback = {
 155                 .channels_min = 2,
 156                 .channels_max = 2,
 157                 .rates = SNDRV_PCM_RATE_KNOT,
 158                 .formats = SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_U32_LE,
 159         },
 160         .capture = {
 161                 .channels_min = 2,
 162                 .channels_max = 2,
 163                 .rates = SNDRV_PCM_RATE_KNOT,
 164                 .formats = SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_U32_LE,
 165         },
 166         .ops = &axi_i2s_dai_ops,
 167         .symmetric_rates = 1,
 168 };
 169
 170 static const struct snd_soc_component_driver axi_i2s_component = {
 171         .name = "axi-i2s",
 172 };
 173
 174 static const struct regmap_config axi_i2s_regmap_config = {
 175         .reg_bits = 32,
 176         .reg_stride = 4,
 177         .val_bits = 32,
 178         .max_register = AXI_I2S_REG_STATUS,
 179 };
 180
 181 static int axi_i2s_probe(struct platform_device *pdev)
 182 {
 183         struct resource *res;
 184         struct axi_i2s *i2s;
 185         void __iomem *base;
 186         int ret;
 187
 188         i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
 189         if (!i2s)
 190                 return -ENOMEM;
 191
 192         platform_set_drvdata(pdev, i2s);
 193
 194         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 195         base = devm_ioremap_resource(&pdev->dev, res);
 196         if (IS_ERR(base))
 197                 return PTR_ERR(base);
 198
 199         i2s->regmap = devm_regmap_init_mmio(&pdev->dev, base,
 200                 &axi_i2s_regmap_config);
 201         if (IS_ERR(i2s->regmap))
 202                 return PTR_ERR(i2s->regmap);
 203
 204         i2s->clk = devm_clk_get(&pdev->dev, "axi");
 205         if (IS_ERR(i2s->clk))
 206                 return PTR_ERR(i2s->clk);
 207
 208         i2s->clk_ref = devm_clk_get(&pdev->dev, "ref");
 209         if (IS_ERR(i2s->clk_ref))
 210                 return PTR_ERR(i2s->clk_ref);
 211
 212         ret = clk_prepare_enable(i2s->clk);
 213         if (ret)
 214                 return ret;
 215
 216         i2s->playback_dma_data.addr = res->start + AXI_I2S_REG_TX_FIFO;
 217         i2s->playback_dma_data.addr_width = 4;
 218         i2s->playback_dma_data.maxburst = 1;
 219
 220         i2s->capture_dma_data.addr = res->start + AXI_I2S_REG_RX_FIFO;
 221         i2s->capture_dma_data.addr_width = 4;
 222         i2s->capture_dma_data.maxburst = 1;
 223
 224         i2s->ratnum.num = clk_get_rate(i2s->clk_ref) / 2 / AXI_I2S_BITS_PER_FRAME;
 225         i2s->ratnum.den_step = 1;
 226         i2s->ratnum.den_min = 1;
 227         i2s->ratnum.den_max = 64;
 228
 229         i2s->rate_constraints.rats = &i2s->ratnum;
 230         i2s->rate_constraints.nrats = 1;
 231
 232         regmap_write(i2s->regmap, AXI_I2S_REG_RESET, AXI_I2S_RESET_GLOBAL);
 233
 234         ret = devm_snd_soc_register_component(&pdev->dev, &axi_i2s_component,
 235                                          &axi_i2s_dai, 1);
 236         if (ret)
 237                 goto err_clk_disable;
 238
 239         ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
 240         if (ret)
 241                 goto err_clk_disable;
 242
 243         return 0;
 244
 245 err_clk_disable:
 246         clk_disable_unprepare(i2s->clk);
 247         return ret;
 248 }
 249
 250 static int axi_i2s_dev_remove(struct platform_device *pdev)
 251 {
 252         struct axi_i2s *i2s = platform_get_drvdata(pdev);
 253
 254         clk_disable_unprepare(i2s->clk);
 255
 256         return 0;
 257 }
 258
 259 static const struct of_device_id axi_i2s_of_match[] = {
 260         { .compatible = "adi,axi-i2s-1.00.a", },
 261         {},
 262 };
 263 MODULE_DEVICE_TABLE(of, axi_i2s_of_match);
 264
 265 static struct platform_driver axi_i2s_driver = {
 266         .driver = {
 267                 .name = "axi-i2s",
 268                 .of_match_table = axi_i2s_of_match,
 269         },
 270         .probe = axi_i2s_probe,
 271         .remove = axi_i2s_dev_remove,
 272 };
 273 module_platform_driver(axi_i2s_driver);
 274
 275 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
 276 MODULE_DESCRIPTION("AXI I2S driver");
 277 MODULE_LICENSE("GPL");