--- /dev/null
+/*
+ * Copyright (C) 2012-2013, Analog Devices Inc.
+ * Author: Lars-Peter Clausen <lars@metafoo.de>
+ *
+ * Licensed under the GPL-2.
+ */
+
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+#include <linux/of.h>
+#include <linux/clk.h>
+#include <linux/regmap.h>
+
+#include <sound/core.h>
+#include <sound/pcm.h>
+#include <sound/pcm_params.h>
+#include <sound/soc.h>
+#include <sound/initval.h>
+#include <sound/dmaengine_pcm.h>
+
+#define AXI_SPDIF_REG_CTRL 0x0
+#define AXI_SPDIF_REG_STAT 0x4
+#define AXI_SPDIF_REG_TX_FIFO 0xc
+
+#define AXI_SPDIF_CTRL_TXDATA BIT(1)
+#define AXI_SPDIF_CTRL_TXEN BIT(0)
+#define AXI_SPDIF_CTRL_CLKDIV_OFFSET 8
+#define AXI_SPDIF_CTRL_CLKDIV_MASK (0xff << 8)
+
+#define AXI_SPDIF_FREQ_44100 (0x0 << 6)
+#define AXI_SPDIF_FREQ_48000 (0x1 << 6)
+#define AXI_SPDIF_FREQ_32000 (0x2 << 6)
+#define AXI_SPDIF_FREQ_NA (0x3 << 6)
+
+struct axi_spdif {
+ struct regmap *regmap;
+ struct clk *clk;
+ struct clk *clk_ref;
+
+ struct snd_dmaengine_dai_dma_data dma_data;
+
+ struct snd_ratnum ratnum;
+ struct snd_pcm_hw_constraint_ratnums rate_constraints;
+};
+
+static int axi_spdif_trigger(struct snd_pcm_substream *substream, int cmd,
+ struct snd_soc_dai *dai)
+{
+ struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
+ unsigned int val;
+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ case SNDRV_PCM_TRIGGER_RESUME:
+ case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+ val = AXI_SPDIF_CTRL_TXDATA;
+ break;
+ case SNDRV_PCM_TRIGGER_STOP:
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+ val = 0;
+ break;
+ default:
+ return -EINVAL;
+ }
+
+ regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
+ AXI_SPDIF_CTRL_TXDATA, val);
+
+ return 0;
+}
+
+static int axi_spdif_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
+{
+ struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
+ unsigned int rate = params_rate(params);
+ unsigned int clkdiv, stat;
+
+ switch (params_rate(params)) {
+ case 32000:
+ stat = AXI_SPDIF_FREQ_32000;
+ break;
+ case 44100:
+ stat = AXI_SPDIF_FREQ_44100;
+ break;
+ case 48000:
+ stat = AXI_SPDIF_FREQ_48000;
+ break;
+ default:
+ stat = AXI_SPDIF_FREQ_NA;
+ break;
+ }
+
+ clkdiv = DIV_ROUND_CLOSEST(clk_get_rate(spdif->clk_ref),
+ rate * 64 * 2) - 1;
+ clkdiv <<= AXI_SPDIF_CTRL_CLKDIV_OFFSET;
+
+ regmap_write(spdif->regmap, AXI_SPDIF_REG_STAT, stat);
+ regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
+ AXI_SPDIF_CTRL_CLKDIV_MASK, clkdiv);
+
+ return 0;
+}
+
+static int axi_spdif_dai_probe(struct snd_soc_dai *dai)
+{
+ struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
+
+ snd_soc_dai_init_dma_data(dai, &spdif->dma_data, NULL);
+
+ return 0;
+}
+
+static int axi_spdif_startup(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
+ int ret;
+
+ ret = snd_pcm_hw_constraint_ratnums(substream->runtime, 0,
+ SNDRV_PCM_HW_PARAM_RATE,
+ &spdif->rate_constraints);
+ if (ret)
+ return ret;
+
+ ret = clk_prepare_enable(spdif->clk_ref);
+ if (ret)
+ return ret;
+
+ regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
+ AXI_SPDIF_CTRL_TXEN, AXI_SPDIF_CTRL_TXEN);
+
+ return 0;
+}
+
+static void axi_spdif_shutdown(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct axi_spdif *spdif = snd_soc_dai_get_drvdata(dai);
+
+ regmap_update_bits(spdif->regmap, AXI_SPDIF_REG_CTRL,
+ AXI_SPDIF_CTRL_TXEN, 0);
+
+ clk_disable_unprepare(spdif->clk_ref);
+}
+
+static const struct snd_soc_dai_ops axi_spdif_dai_ops = {
+ .startup = axi_spdif_startup,
+ .shutdown = axi_spdif_shutdown,
+ .trigger = axi_spdif_trigger,
+ .hw_params = axi_spdif_hw_params,
+};
+
+static struct snd_soc_dai_driver axi_spdif_dai = {
+ .probe = axi_spdif_dai_probe,
+ .playback = {
+ .channels_min = 2,
+ .channels_max = 2,
+ .rates = SNDRV_PCM_RATE_KNOT,
+ .formats = SNDRV_PCM_FMTBIT_S16_LE,
+ },
+ .ops = &axi_spdif_dai_ops,
+};
+
+static const struct snd_soc_component_driver axi_spdif_component = {
+ .name = "axi-spdif",
+};
+
+static const struct regmap_config axi_spdif_regmap_config = {
+ .reg_bits = 32,
+ .reg_stride = 4,
+ .val_bits = 32,
+ .max_register = AXI_SPDIF_REG_STAT,
+};
+
+static int axi_spdif_probe(struct platform_device *pdev)
+{
+ struct axi_spdif *spdif;
+ struct resource *res;
+ void __iomem *base;
+ int ret;
+
+ spdif = devm_kzalloc(&pdev->dev, sizeof(*spdif), GFP_KERNEL);
+ if (!spdif)
+ return -ENOMEM;
+
+ platform_set_drvdata(pdev, spdif);
+
+ res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+ base = devm_ioremap_resource(&pdev->dev, res);
+ if (IS_ERR(base))
+ return PTR_ERR(base);
+
+ spdif->regmap = devm_regmap_init_mmio(&pdev->dev, base,
+ &axi_spdif_regmap_config);
+ if (IS_ERR(spdif->regmap))
+ return PTR_ERR(spdif->regmap);
+
+ spdif->clk = devm_clk_get(&pdev->dev, "axi");
+ if (IS_ERR(spdif->clk))
+ return PTR_ERR(spdif->clk);
+
+ spdif->clk_ref = devm_clk_get(&pdev->dev, "ref");
+ if (IS_ERR(spdif->clk_ref))
+ return PTR_ERR(spdif->clk_ref);
+
+ ret = clk_prepare_enable(spdif->clk);
+ if (ret)
+ return ret;
+
+ spdif->dma_data.addr = res->start + AXI_SPDIF_REG_TX_FIFO;
+ spdif->dma_data.addr_width = 4;
+ spdif->dma_data.maxburst = 1;
+
+ spdif->ratnum.num = clk_get_rate(spdif->clk_ref) / 128;
+ spdif->ratnum.den_step = 1;
+ spdif->ratnum.den_min = 1;
+ spdif->ratnum.den_max = 64;
+
+ spdif->rate_constraints.rats = &spdif->ratnum;
+ spdif->rate_constraints.nrats = 1;
+
+ ret = devm_snd_soc_register_component(&pdev->dev, &axi_spdif_component,
+ &axi_spdif_dai, 1);
+ if (ret)
+ goto err_clk_disable;
+
+ ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
+ if (ret)
+ goto err_clk_disable;
+
+ return 0;
+
+err_clk_disable:
+ clk_disable_unprepare(spdif->clk);
+ return ret;
+}
+
+static int axi_spdif_dev_remove(struct platform_device *pdev)
+{
+ struct axi_spdif *spdif = platform_get_drvdata(pdev);
+
+ clk_disable_unprepare(spdif->clk);
+
+ return 0;
+}
+
+static const struct of_device_id axi_spdif_of_match[] = {
+ { .compatible = "adi,axi-spdif-tx-1.00.a", },
+ {},
+};
+MODULE_DEVICE_TABLE(of, axi_spdif_of_match);
+
+static struct platform_driver axi_spdif_driver = {
+ .driver = {
+ .name = "axi-spdif",
+ .of_match_table = axi_spdif_of_match,
+ },
+ .probe = axi_spdif_probe,
+ .remove = axi_spdif_dev_remove,
+};
+module_platform_driver(axi_spdif_driver);
+
+MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
+MODULE_DESCRIPTION("AXI SPDIF driver");
+MODULE_LICENSE("GPL");
Code Review / kvmfornfv.git / blobdiff