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_request_and_ioremap(&pdev->dev, res); 196 if (!base) 197 return -EBUSY; 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, 240 SND_DMAENGINE_PCM_FLAG_NO_RESIDUE); 241 if (ret) 242 goto err_clk_disable; 243 244 err_clk_disable: 245 clk_disable_unprepare(i2s->clk); 246 return ret; 247 } 248 249 static int axi_i2s_dev_remove(struct platform_device *pdev) 250 { 251 struct axi_i2s *i2s = platform_get_drvdata(pdev); 252 253 clk_disable_unprepare(i2s->clk); 254 255 return 0; 256 } 257 258 static const struct of_device_id axi_i2s_of_match[] = { 259 { .compatible = "adi,axi-i2s-1.00.a", }, 260 {}, 261 }; 262 MODULE_DEVICE_TABLE(of, axi_i2s_of_match); 263 264 static struct platform_driver axi_i2s_driver = { 265 .driver = { 266 .name = "axi-i2s", 267 .owner = THIS_MODULE, 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"); 278