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 bool has_capture; 47 bool has_playback; 48 49 struct snd_soc_dai_driver dai_driver; 50 51 struct snd_dmaengine_dai_dma_data capture_dma_data; 52 struct snd_dmaengine_dai_dma_data playback_dma_data; 53 54 struct snd_ratnum ratnum; 55 struct snd_pcm_hw_constraint_ratnums rate_constraints; 56 }; 57 58 static int axi_i2s_trigger(struct snd_pcm_substream *substream, int cmd, 59 struct snd_soc_dai *dai) 60 { 61 struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai); 62 unsigned int mask, val; 63 64 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) 65 mask = AXI_I2S_CTRL_RX_EN; 66 else 67 mask = AXI_I2S_CTRL_TX_EN; 68 69 switch (cmd) { 70 case SNDRV_PCM_TRIGGER_START: 71 case SNDRV_PCM_TRIGGER_RESUME: 72 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 73 val = mask; 74 break; 75 case SNDRV_PCM_TRIGGER_STOP: 76 case SNDRV_PCM_TRIGGER_SUSPEND: 77 case SNDRV_PCM_TRIGGER_PAUSE_PUSH: 78 val = 0; 79 break; 80 default: 81 return -EINVAL; 82 } 83 84 regmap_update_bits(i2s->regmap, AXI_I2S_REG_CTRL, mask, val); 85 86 return 0; 87 } 88 89 static int axi_i2s_hw_params(struct snd_pcm_substream *substream, 90 struct snd_pcm_hw_params *params, struct snd_soc_dai *dai) 91 { 92 struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai); 93 unsigned int bclk_div, word_size; 94 unsigned int bclk_rate; 95 96 bclk_rate = params_rate(params) * AXI_I2S_BITS_PER_FRAME; 97 98 word_size = AXI_I2S_BITS_PER_FRAME / 2 - 1; 99 bclk_div = DIV_ROUND_UP(clk_get_rate(i2s->clk_ref), bclk_rate) / 2 - 1; 100 101 regmap_write(i2s->regmap, AXI_I2S_REG_CLK_CTRL, (word_size << 16) | 102 bclk_div); 103 104 return 0; 105 } 106 107 static int axi_i2s_startup(struct snd_pcm_substream *substream, 108 struct snd_soc_dai *dai) 109 { 110 struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai); 111 uint32_t mask; 112 int ret; 113 114 if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) 115 mask = AXI_I2S_RESET_RX_FIFO; 116 else 117 mask = AXI_I2S_RESET_TX_FIFO; 118 119 regmap_write(i2s->regmap, AXI_I2S_REG_RESET, mask); 120 121 ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0, 122 SNDRV_PCM_HW_PARAM_RATE, 123 &i2s->rate_constraints); 124 if (ret) 125 return ret; 126 127 return clk_prepare_enable(i2s->clk_ref); 128 } 129 130 static void axi_i2s_shutdown(struct snd_pcm_substream *substream, 131 struct snd_soc_dai *dai) 132 { 133 struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai); 134 135 clk_disable_unprepare(i2s->clk_ref); 136 } 137 138 static int axi_i2s_dai_probe(struct snd_soc_dai *dai) 139 { 140 struct axi_i2s *i2s = snd_soc_dai_get_drvdata(dai); 141 142 snd_soc_dai_init_dma_data( 143 dai, 144 i2s->has_playback ? &i2s->playback_dma_data : NULL, 145 i2s->has_capture ? &i2s->capture_dma_data : NULL); 146 147 return 0; 148 } 149 150 static const struct snd_soc_dai_ops axi_i2s_dai_ops = { 151 .startup = axi_i2s_startup, 152 .shutdown = axi_i2s_shutdown, 153 .trigger = axi_i2s_trigger, 154 .hw_params = axi_i2s_hw_params, 155 }; 156 157 static struct snd_soc_dai_driver axi_i2s_dai = { 158 .probe = axi_i2s_dai_probe, 159 .ops = &axi_i2s_dai_ops, 160 .symmetric_rates = 1, 161 }; 162 163 static const struct snd_soc_component_driver axi_i2s_component = { 164 .name = "axi-i2s", 165 }; 166 167 static const struct regmap_config axi_i2s_regmap_config = { 168 .reg_bits = 32, 169 .reg_stride = 4, 170 .val_bits = 32, 171 .max_register = AXI_I2S_REG_STATUS, 172 }; 173 174 static void axi_i2s_parse_of(struct axi_i2s *i2s, const struct device_node *np) 175 { 176 struct property *dma_names; 177 const char *dma_name; 178 179 of_property_for_each_string(np, "dma-names", dma_names, dma_name) { 180 if (strcmp(dma_name, "rx") == 0) 181 i2s->has_capture = true; 182 if (strcmp(dma_name, "tx") == 0) 183 i2s->has_playback = true; 184 } 185 } 186 187 static int axi_i2s_probe(struct platform_device *pdev) 188 { 189 struct resource *res; 190 struct axi_i2s *i2s; 191 void __iomem *base; 192 int ret; 193 194 i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL); 195 if (!i2s) 196 return -ENOMEM; 197 198 platform_set_drvdata(pdev, i2s); 199 200 axi_i2s_parse_of(i2s, pdev->dev.of_node); 201 202 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 203 base = devm_ioremap_resource(&pdev->dev, res); 204 if (IS_ERR(base)) 205 return PTR_ERR(base); 206 207 i2s->regmap = devm_regmap_init_mmio(&pdev->dev, base, 208 &axi_i2s_regmap_config); 209 if (IS_ERR(i2s->regmap)) 210 return PTR_ERR(i2s->regmap); 211 212 i2s->clk = devm_clk_get(&pdev->dev, "axi"); 213 if (IS_ERR(i2s->clk)) 214 return PTR_ERR(i2s->clk); 215 216 i2s->clk_ref = devm_clk_get(&pdev->dev, "ref"); 217 if (IS_ERR(i2s->clk_ref)) 218 return PTR_ERR(i2s->clk_ref); 219 220 ret = clk_prepare_enable(i2s->clk); 221 if (ret) 222 return ret; 223 224 if (i2s->has_playback) { 225 axi_i2s_dai.playback.channels_min = 2; 226 axi_i2s_dai.playback.channels_max = 2; 227 axi_i2s_dai.playback.rates = SNDRV_PCM_RATE_KNOT; 228 axi_i2s_dai.playback.formats = 229 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_U32_LE; 230 231 i2s->playback_dma_data.addr = res->start + AXI_I2S_REG_TX_FIFO; 232 i2s->playback_dma_data.addr_width = 4; 233 i2s->playback_dma_data.maxburst = 1; 234 } 235 236 if (i2s->has_capture) { 237 axi_i2s_dai.capture.channels_min = 2; 238 axi_i2s_dai.capture.channels_max = 2; 239 axi_i2s_dai.capture.rates = SNDRV_PCM_RATE_KNOT; 240 axi_i2s_dai.capture.formats = 241 SNDRV_PCM_FMTBIT_S32_LE | SNDRV_PCM_FMTBIT_U32_LE; 242 243 i2s->capture_dma_data.addr = res->start + AXI_I2S_REG_RX_FIFO; 244 i2s->capture_dma_data.addr_width = 4; 245 i2s->capture_dma_data.maxburst = 1; 246 } 247 248 i2s->ratnum.num = clk_get_rate(i2s->clk_ref) / 2 / AXI_I2S_BITS_PER_FRAME; 249 i2s->ratnum.den_step = 1; 250 i2s->ratnum.den_min = 1; 251 i2s->ratnum.den_max = 64; 252 253 i2s->rate_constraints.rats = &i2s->ratnum; 254 i2s->rate_constraints.nrats = 1; 255 256 regmap_write(i2s->regmap, AXI_I2S_REG_RESET, AXI_I2S_RESET_GLOBAL); 257 258 ret = devm_snd_soc_register_component(&pdev->dev, &axi_i2s_component, 259 &axi_i2s_dai, 1); 260 if (ret) 261 goto err_clk_disable; 262 263 ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0); 264 if (ret) 265 goto err_clk_disable; 266 267 dev_info(&pdev->dev, "probed, capture %s, playback %s\n", 268 i2s->has_capture ? "enabled" : "disabled", 269 i2s->has_playback ? "enabled" : "disabled"); 270 271 return 0; 272 273 err_clk_disable: 274 clk_disable_unprepare(i2s->clk); 275 return ret; 276 } 277 278 static int axi_i2s_dev_remove(struct platform_device *pdev) 279 { 280 struct axi_i2s *i2s = platform_get_drvdata(pdev); 281 282 clk_disable_unprepare(i2s->clk); 283 284 return 0; 285 } 286 287 static const struct of_device_id axi_i2s_of_match[] = { 288 { .compatible = "adi,axi-i2s-1.00.a", }, 289 {}, 290 }; 291 MODULE_DEVICE_TABLE(of, axi_i2s_of_match); 292 293 static struct platform_driver axi_i2s_driver = { 294 .driver = { 295 .name = "axi-i2s", 296 .of_match_table = axi_i2s_of_match, 297 }, 298 .probe = axi_i2s_probe, 299 .remove = axi_i2s_dev_remove, 300 }; 301 module_platform_driver(axi_i2s_driver); 302 303 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 304 MODULE_DESCRIPTION("AXI I2S driver"); 305 MODULE_LICENSE("GPL"); 306