1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * Copyright (C) 2012-2013, Analog Devices Inc. 4 * Author: Lars-Peter Clausen <lars@metafoo.de> 5 */ 6 7 #include <linux/init.h> 8 #include <linux/kernel.h> 9 #include <linux/module.h> 10 #include <linux/platform_device.h> 11 #include <linux/slab.h> 12 #include <linux/of.h> 13 #include <linux/clk.h> 14 #include <linux/regmap.h> 15 16 #include <sound/core.h> 17 #include <sound/pcm.h> 18 #include <sound/pcm_params.h> 19 #include <sound/soc.h> 20 #include <sound/initval.h> 21 #include <sound/dmaengine_pcm.h> 22 23 #define AXI_SPDIF_REG_CTRL 0x0 24 #define AXI_SPDIF_REG_STAT 0x4 25 #define AXI_SPDIF_REG_TX_FIFO 0xc 26 27 #define AXI_SPDIF_CTRL_TXDATA BIT(1) 28 #define AXI_SPDIF_CTRL_TXEN BIT(0) 29 #define AXI_SPDIF_CTRL_CLKDIV_OFFSET 8 30 #define AXI_SPDIF_CTRL_CLKDIV_MASK (0xff << 8) 31 32 #define AXI_SPDIF_FREQ_44100 (0x0 << 6) 33 #define AXI_SPDIF_FREQ_48000 (0x1 << 6) 34 #define AXI_SPDIF_FREQ_32000 (0x2 << 6) 35 #define AXI_SPDIF_FREQ_NA (0x3 << 6) 36 37 struct axi_spdif { 38 struct regmap *regmap; 39 struct clk *clk; 40 struct clk *clk_ref; 41 42 struct snd_dmaengine_dai_dma_data dma_data; 43 44 struct snd_ratnum ratnum; 45 struct snd_pcm_hw_constraint_ratnums rate_constraints; 46 }; 47 48 static int axi_spdif_trigger(struct snd_pcm_substream *substream, int cmd, 49 struct snd_soc_dai *dai) 50 { 51 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai); 52 unsigned int val; 53 54 switch (cmd) { 55 case SNDRV_PCM_TRIGGER_START: 56 case SNDRV_PCM_TRIGGER_RESUME: 57 case SNDRV_PCM_TRIGGER_PAUSE_RELEASE: 58 val = AXI_SPDIF_CTRL_TXDATA; 59 break; 60 case SNDRV_PCM_TRIGGER_STOP: 61 case SNDRV_PCM_TRIGGER_SUSPEND: 62 case SNDRV_PCM_TRIGGER_PAUSE_PUSH: 63 val = 0; 64 break; 65 default: 66 return -EINVAL; 67 } 68 69 regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL, 70 AXI_SPDIF_CTRL_TXDATA, val); 71 72 return 0; 73 } 74 75 static int axi_spdif_hw_params(struct snd_pcm_substream *substream, 76 struct snd_pcm_hw_params *params, struct snd_soc_dai *dai) 77 { 78 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai); 79 unsigned int rate = params_rate(params); 80 unsigned int clkdiv, stat; 81 82 switch (params_rate(params)) { 83 case 32000: 84 stat = AXI_SPDIF_FREQ_32000; 85 break; 86 case 44100: 87 stat = AXI_SPDIF_FREQ_44100; 88 break; 89 case 48000: 90 stat = AXI_SPDIF_FREQ_48000; 91 break; 92 default: 93 stat = AXI_SPDIF_FREQ_NA; 94 break; 95 } 96 97 clkdiv = DIV_ROUND_CLOSEST(clk_get_rate(spdif->clk_ref), 98 rate * 64 * 2) - 1; 99 clkdiv <<= AXI_SPDIF_CTRL_CLKDIV_OFFSET; 100 101 regmap_write(spdif->regmap, AXI_SPDIF_REG_STAT, stat); 102 regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL, 103 AXI_SPDIF_CTRL_CLKDIV_MASK, clkdiv); 104 105 return 0; 106 } 107 108 static int axi_spdif_dai_probe(struct snd_soc_dai *dai) 109 { 110 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai); 111 112 snd_soc_dai_init_dma_data(dai, &spdif->dma_data, NULL); 113 114 return 0; 115 } 116 117 static int axi_spdif_startup(struct snd_pcm_substream *substream, 118 struct snd_soc_dai *dai) 119 { 120 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai); 121 int ret; 122 123 ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0, 124 SNDRV_PCM_HW_PARAM_RATE, 125 &spdif->rate_constraints); 126 if (ret) 127 return ret; 128 129 ret = clk_prepare_enable(spdif->clk_ref); 130 if (ret) 131 return ret; 132 133 regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL, 134 AXI_SPDIF_CTRL_TXEN, AXI_SPDIF_CTRL_TXEN); 135 136 return 0; 137 } 138 139 static void axi_spdif_shutdown(struct snd_pcm_substream *substream, 140 struct snd_soc_dai *dai) 141 { 142 struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai); 143 144 regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL, 145 AXI_SPDIF_CTRL_TXEN, 0); 146 147 clk_disable_unprepare(spdif->clk_ref); 148 } 149 150 static const struct snd_soc_dai_ops axi_spdif_dai_ops = { 151 .startup = axi_spdif_startup, 152 .shutdown = axi_spdif_shutdown, 153 .trigger = axi_spdif_trigger, 154 .hw_params = axi_spdif_hw_params, 155 }; 156 157 static struct snd_soc_dai_driver axi_spdif_dai = { 158 .probe = axi_spdif_dai_probe, 159 .playback = { 160 .channels_min = 2, 161 .channels_max = 2, 162 .rates = SNDRV_PCM_RATE_KNOT, 163 .formats = SNDRV_PCM_FMTBIT_S16_LE, 164 }, 165 .ops = &axi_spdif_dai_ops, 166 }; 167 168 static const struct snd_soc_component_driver axi_spdif_component = { 169 .name = "axi-spdif", 170 }; 171 172 static const struct regmap_config axi_spdif_regmap_config = { 173 .reg_bits = 32, 174 .reg_stride = 4, 175 .val_bits = 32, 176 .max_register = AXI_SPDIF_REG_STAT, 177 }; 178 179 static int axi_spdif_probe(struct platform_device *pdev) 180 { 181 struct axi_spdif *spdif; 182 struct resource *res; 183 void __iomem *base; 184 int ret; 185 186 spdif = devm_kzalloc(&pdev->dev, sizeof(*spdif), GFP_KERNEL); 187 if (!spdif) 188 return -ENOMEM; 189 190 platform_set_drvdata(pdev, spdif); 191 192 res = platform_get_resource(pdev, IORESOURCE_MEM, 0); 193 base = devm_ioremap_resource(&pdev->dev, res); 194 if (IS_ERR(base)) 195 return PTR_ERR(base); 196 197 spdif->regmap = devm_regmap_init_mmio(&pdev->dev, base, 198 &axi_spdif_regmap_config); 199 if (IS_ERR(spdif->regmap)) 200 return PTR_ERR(spdif->regmap); 201 202 spdif->clk = devm_clk_get(&pdev->dev, "axi"); 203 if (IS_ERR(spdif->clk)) 204 return PTR_ERR(spdif->clk); 205 206 spdif->clk_ref = devm_clk_get(&pdev->dev, "ref"); 207 if (IS_ERR(spdif->clk_ref)) 208 return PTR_ERR(spdif->clk_ref); 209 210 ret = clk_prepare_enable(spdif->clk); 211 if (ret) 212 return ret; 213 214 spdif->dma_data.addr = res->start + AXI_SPDIF_REG_TX_FIFO; 215 spdif->dma_data.addr_width = 4; 216 spdif->dma_data.maxburst = 1; 217 218 spdif->ratnum.num = clk_get_rate(spdif->clk_ref) / 128; 219 spdif->ratnum.den_step = 1; 220 spdif->ratnum.den_min = 1; 221 spdif->ratnum.den_max = 64; 222 223 spdif->rate_constraints.rats = &spdif->ratnum; 224 spdif->rate_constraints.nrats = 1; 225 226 ret = devm_snd_soc_register_component(&pdev->dev, &axi_spdif_component, 227 &axi_spdif_dai, 1); 228 if (ret) 229 goto err_clk_disable; 230 231 ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0); 232 if (ret) 233 goto err_clk_disable; 234 235 return 0; 236 237 err_clk_disable: 238 clk_disable_unprepare(spdif->clk); 239 return ret; 240 } 241 242 static int axi_spdif_dev_remove(struct platform_device *pdev) 243 { 244 struct axi_spdif *spdif = platform_get_drvdata(pdev); 245 246 clk_disable_unprepare(spdif->clk); 247 248 return 0; 249 } 250 251 static const struct of_device_id axi_spdif_of_match[] = { 252 { .compatible = "adi,axi-spdif-tx-1.00.a", }, 253 {}, 254 }; 255 MODULE_DEVICE_TABLE(of, axi_spdif_of_match); 256 257 static struct platform_driver axi_spdif_driver = { 258 .driver = { 259 .name = "axi-spdif", 260 .of_match_table = axi_spdif_of_match, 261 }, 262 .probe = axi_spdif_probe, 263 .remove = axi_spdif_dev_remove, 264 }; 265 module_platform_driver(axi_spdif_driver); 266 267 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); 268 MODULE_DESCRIPTION("AXI SPDIF driver"); 269 MODULE_LICENSE("GPL"); 270