soc/adi/axi-spdif.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * Copyright (C) 2012-2013, Analog Devices Inc.
0004  * Author: Lars-Peter Clausen <lars@metafoo.de>
0005  */
0006
0007 #include <linux/init.h>
0008 #include <linux/kernel.h>
0009 #include <linux/module.h>
0010 #include <linux/platform_device.h>
0011 #include <linux/slab.h>
0012 #include <linux/of.h>
0013 #include <linux/clk.h>
0014 #include <linux/regmap.h>
0015
0016 #include <sound/core.h>
0017 #include <sound/pcm.h>
0018 #include <sound/pcm_params.h>
0019 #include <sound/soc.h>
0020 #include <sound/initval.h>
0021 #include <sound/dmaengine_pcm.h>
0022
0023 #define AXI_SPDIF_REG_CTRL  0x0
0024 #define AXI_SPDIF_REG_STAT  0x4
0025 #define AXI_SPDIF_REG_TX_FIFO   0xc
0026
0027 #define AXI_SPDIF_CTRL_TXDATA BIT(1)
0028 #define AXI_SPDIF_CTRL_TXEN BIT(0)
0029 #define AXI_SPDIF_CTRL_CLKDIV_OFFSET 8
0030 #define AXI_SPDIF_CTRL_CLKDIV_MASK (0xff << 8)
0031
0032 #define AXI_SPDIF_FREQ_44100    (0x0 << 6)
0033 #define AXI_SPDIF_FREQ_48000    (0x1 << 6)
0034 #define AXI_SPDIF_FREQ_32000    (0x2 << 6)
0035 #define AXI_SPDIF_FREQ_NA   (0x3 << 6)
0036
0037 struct axi_spdif {
0038     struct regmap *regmap;
0039     struct clk *clk;
0040     struct clk *clk_ref;
0041
0042     struct snd_dmaengine_dai_dma_data dma_data;
0043
0044     struct snd_ratnum ratnum;
0045     struct snd_pcm_hw_constraint_ratnums rate_constraints;
0046 };
0047
0048 static int axi_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
0049     struct snd_soc_dai *dai)
0050 {
0051     struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
0052     unsigned int val;
0053
0054     switch (cmd) {
0055     case SNDRV_PCM_TRIGGER_START:
0056     case SNDRV_PCM_TRIGGER_RESUME:
0057     case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
0058         val = AXI_SPDIF_CTRL_TXDATA;
0059         break;
0060     case SNDRV_PCM_TRIGGER_STOP:
0061     case SNDRV_PCM_TRIGGER_SUSPEND:
0062     case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
0063         val = 0;
0064         break;
0065     default:
0066         return -EINVAL;
0067     }
0068
0069     regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
0070         AXI_SPDIF_CTRL_TXDATA, val);
0071
0072     return 0;
0073 }
0074
0075 static int axi_spdif_hw_params(struct snd_pcm_substream *substream,
0076     struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
0077 {
0078     struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
0079     unsigned int rate = params_rate(params);
0080     unsigned int clkdiv, stat;
0081
0082     switch (params_rate(params)) {
0083     case 32000:
0084         stat = AXI_SPDIF_FREQ_32000;
0085         break;
0086     case 44100:
0087         stat = AXI_SPDIF_FREQ_44100;
0088         break;
0089     case 48000:
0090         stat = AXI_SPDIF_FREQ_48000;
0091         break;
0092     default:
0093         stat = AXI_SPDIF_FREQ_NA;
0094         break;
0095     }
0096
0097     clkdiv = DIV_ROUND_CLOSEST(clk_get_rate(spdif->clk_ref),
0098             rate * 64 * 2) - 1;
0099     clkdiv <<= AXI_SPDIF_CTRL_CLKDIV_OFFSET;
0100
0101     regmap_write(spdif->regmap, AXI_SPDIF_REG_STAT, stat);
0102     regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
0103         AXI_SPDIF_CTRL_CLKDIV_MASK, clkdiv);
0104
0105     return 0;
0106 }
0107
0108 static int axi_spdif_dai_probe(struct snd_soc_dai *dai)
0109 {
0110     struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
0111
0112     snd_soc_dai_init_dma_data(dai, &spdif->dma_data, NULL);
0113
0114     return 0;
0115 }
0116
0117 static int axi_spdif_startup(struct snd_pcm_substream *substream,
0118     struct snd_soc_dai *dai)
0119 {
0120     struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
0121     int ret;
0122
0123     ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0,
0124                SNDRV_PCM_HW_PARAM_RATE,
0125                &spdif->rate_constraints);
0126     if (ret)
0127         return ret;
0128
0129     ret = clk_prepare_enable(spdif->clk_ref);
0130     if (ret)
0131         return ret;
0132
0133     regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
0134         AXI_SPDIF_CTRL_TXEN, AXI_SPDIF_CTRL_TXEN);
0135
0136     return 0;
0137 }
0138
0139 static void axi_spdif_shutdown(struct snd_pcm_substream *substream,
0140     struct snd_soc_dai *dai)
0141 {
0142     struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
0143
0144     regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
0145         AXI_SPDIF_CTRL_TXEN, 0);
0146
0147     clk_disable_unprepare(spdif->clk_ref);
0148 }
0149
0150 static const struct snd_soc_dai_ops axi_spdif_dai_ops = {
0151     .startup = axi_spdif_startup,
0152     .shutdown = axi_spdif_shutdown,
0153     .trigger = axi_spdif_trigger,
0154     .hw_params = axi_spdif_hw_params,
0155 };
0156
0157 static struct snd_soc_dai_driver axi_spdif_dai = {
0158     .probe = axi_spdif_dai_probe,
0159     .playback = {
0160         .channels_min = 2,
0161         .channels_max = 2,
0162         .rates = SNDRV_PCM_RATE_KNOT,
0163         .formats = SNDRV_PCM_FMTBIT_S16_LE,
0164     },
0165     .ops = &axi_spdif_dai_ops,
0166 };
0167
0168 static const struct snd_soc_component_driver axi_spdif_component = {
0169     .name = "axi-spdif",
0170     .legacy_dai_naming = 1,
0171 };
0172
0173 static const struct regmap_config axi_spdif_regmap_config = {
0174     .reg_bits = 32,
0175     .reg_stride = 4,
0176     .val_bits = 32,
0177     .max_register = AXI_SPDIF_REG_STAT,
0178 };
0179
0180 static int axi_spdif_probe(struct platform_device *pdev)
0181 {
0182     struct axi_spdif *spdif;
0183     struct resource *res;
0184     void __iomem *base;
0185     int ret;
0186
0187     spdif = devm_kzalloc(&pdev->dev, sizeof(*spdif), GFP_KERNEL);
0188     if (!spdif)
0189         return -ENOMEM;
0190
0191     platform_set_drvdata(pdev, spdif);
0192
0193     base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
0194     if (IS_ERR(base))
0195         return PTR_ERR(base);
0196
0197     spdif->regmap = devm_regmap_init_mmio(&pdev->dev, base,
0198                         &axi_spdif_regmap_config);
0199     if (IS_ERR(spdif->regmap))
0200         return PTR_ERR(spdif->regmap);
0201
0202     spdif->clk = devm_clk_get(&pdev->dev, "axi");
0203     if (IS_ERR(spdif->clk))
0204         return PTR_ERR(spdif->clk);
0205
0206     spdif->clk_ref = devm_clk_get(&pdev->dev, "ref");
0207     if (IS_ERR(spdif->clk_ref))
0208         return PTR_ERR(spdif->clk_ref);
0209
0210     ret = clk_prepare_enable(spdif->clk);
0211     if (ret)
0212         return ret;
0213
0214     spdif->dma_data.addr = res->start + AXI_SPDIF_REG_TX_FIFO;
0215     spdif->dma_data.addr_width = 4;
0216     spdif->dma_data.maxburst = 1;
0217
0218     spdif->ratnum.num = clk_get_rate(spdif->clk_ref) / 128;
0219     spdif->ratnum.den_step = 1;
0220     spdif->ratnum.den_min = 1;
0221     spdif->ratnum.den_max = 64;
0222
0223     spdif->rate_constraints.rats = &spdif->ratnum;
0224     spdif->rate_constraints.nrats = 1;
0225
0226     ret = devm_snd_soc_register_component(&pdev->dev, &axi_spdif_component,
0227                      &axi_spdif_dai, 1);
0228     if (ret)
0229         goto err_clk_disable;
0230
0231     ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
0232     if (ret)
0233         goto err_clk_disable;
0234
0235     return 0;
0236
0237 err_clk_disable:
0238     clk_disable_unprepare(spdif->clk);
0239     return ret;
0240 }
0241
0242 static int axi_spdif_dev_remove(struct platform_device *pdev)
0243 {
0244     struct axi_spdif *spdif = platform_get_drvdata(pdev);
0245
0246     clk_disable_unprepare(spdif->clk);
0247
0248     return 0;
0249 }
0250
0251 static const struct of_device_id axi_spdif_of_match[] = {
0252     { .compatible = "adi,axi-spdif-tx-1.00.a", },
0253     {},
0254 };
0255 MODULE_DEVICE_TABLE(of, axi_spdif_of_match);
0256
0257 static struct platform_driver axi_spdif_driver = {
0258     .driver = {
0259         .name = "axi-spdif",
0260         .of_match_table = axi_spdif_of_match,
0261     },
0262     .probe = axi_spdif_probe,
0263     .remove = axi_spdif_dev_remove,
0264 };
0265 module_platform_driver(axi_spdif_driver);
0266
0267 MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
0268 MODULE_DESCRIPTION("AXI SPDIF driver");
0269 MODULE_LICENSE("GPL");