ASoC: add driver for Rockchip RK3xxx I2S controller

Add driver for i2s controller found on rk3066, rk3168 and rk3288
processors from rockchip.

Tested on the RK3288 SDK board.

Signed-off-by: Jianqun Xu <xjq@rock-chips.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
diff --git a/sound/soc/rockchip/rockchip_i2s.c b/sound/soc/rockchip/rockchip_i2s.c
new file mode 100644
index 0000000..af1d8eb
--- /dev/null
+++ b/sound/soc/rockchip/rockchip_i2s.c
@@ -0,0 +1,530 @@
+/* sound/soc/rockchip/rockchip_i2s.c
+ *
+ * ALSA SoC Audio Layer - Rockchip I2S Controller driver
+ *
+ * Copyright (c) 2014 Rockchip Electronics Co. Ltd.
+ * Author: Jianqun <jay.xu@rock-chips.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/delay.h>
+#include <linux/of_gpio.h>
+#include <linux/clk.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <sound/pcm_params.h>
+#include <sound/dmaengine_pcm.h>
+
+#include "rockchip_i2s.h"
+
+#define DRV_NAME "rockchip-i2s"
+
+struct rk_i2s_dev {
+	struct device *dev;
+
+	struct clk *hclk;
+	struct clk *mclk;
+
+	struct snd_dmaengine_dai_dma_data capture_dma_data;
+	struct snd_dmaengine_dai_dma_data playback_dma_data;
+
+	struct regmap *regmap;
+
+/*
+ * Used to indicate the tx/rx status.
+ * I2S controller hopes to start the tx and rx together,
+ * also to stop them when they are both try to stop.
+*/
+	bool tx_start;
+	bool rx_start;
+};
+
+static int i2s_runtime_suspend(struct device *dev)
+{
+	struct rk_i2s_dev *i2s = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(i2s->mclk);
+
+	return 0;
+}
+
+static int i2s_runtime_resume(struct device *dev)
+{
+	struct rk_i2s_dev *i2s = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(i2s->mclk);
+	if (ret) {
+		dev_err(i2s->dev, "clock enable failed %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static inline struct rk_i2s_dev *to_info(struct snd_soc_dai *dai)
+{
+	return snd_soc_dai_get_drvdata(dai);
+}
+
+static void rockchip_snd_txctrl(struct rk_i2s_dev *i2s, int on)
+{
+	unsigned int val = 0;
+	int retry = 10;
+
+	if (on) {
+		regmap_update_bits(i2s->regmap, I2S_DMACR,
+				   I2S_DMACR_TDE_ENABLE, I2S_DMACR_TDE_ENABLE);
+
+		regmap_update_bits(i2s->regmap, I2S_XFER,
+				   I2S_XFER_TXS_START | I2S_XFER_RXS_START,
+				   I2S_XFER_TXS_START | I2S_XFER_RXS_START);
+
+		i2s->tx_start = true;
+	} else {
+		i2s->tx_start = false;
+
+		regmap_update_bits(i2s->regmap, I2S_DMACR,
+				   I2S_DMACR_TDE_ENABLE, I2S_DMACR_TDE_ENABLE);
+
+		if (!i2s->rx_start) {
+			regmap_update_bits(i2s->regmap, I2S_XFER,
+					   I2S_XFER_TXS_START |
+					   I2S_XFER_RXS_START,
+					   I2S_XFER_TXS_STOP |
+					   I2S_XFER_RXS_STOP);
+
+			regmap_update_bits(i2s->regmap, I2S_CLR,
+					   I2S_CLR_TXC | I2S_CLR_TXC,
+					   I2S_CLR_TXC | I2S_CLR_TXC);
+
+			regmap_read(i2s->regmap, I2S_CLR, &val);
+
+			/* Should wait for clear operation to finish */
+			while (val) {
+				regmap_read(i2s->regmap, I2S_CLR, &val);
+				retry--;
+				if (!retry)
+					dev_warn(i2s->dev, "fail to clear\n");
+			}
+		}
+	}
+}
+
+static void rockchip_snd_rxctrl(struct rk_i2s_dev *i2s, int on)
+{
+	unsigned int val = 0;
+	int retry = 10;
+
+	if (on) {
+		regmap_update_bits(i2s->regmap, I2S_DMACR,
+				   I2S_DMACR_RDE_ENABLE, I2S_DMACR_RDE_ENABLE);
+
+		regmap_update_bits(i2s->regmap, I2S_XFER,
+				   I2S_XFER_TXS_START | I2S_XFER_RXS_START,
+				   I2S_XFER_TXS_START | I2S_XFER_RXS_START);
+
+		i2s->rx_start = true;
+	} else {
+		i2s->rx_start = false;
+
+		regmap_update_bits(i2s->regmap, I2S_DMACR,
+				   I2S_DMACR_RDE_ENABLE, I2S_DMACR_RDE_DISABLE);
+
+		if (!i2s->tx_start) {
+			regmap_update_bits(i2s->regmap, I2S_XFER,
+					   I2S_XFER_TXS_START |
+					   I2S_XFER_RXS_START,
+					   I2S_XFER_TXS_STOP |
+					   I2S_XFER_RXS_STOP);
+
+			regmap_update_bits(i2s->regmap, I2S_CLR,
+					   I2S_CLR_TXC | I2S_CLR_TXC,
+					   I2S_CLR_TXC | I2S_CLR_TXC);
+
+			regmap_read(i2s->regmap, I2S_CLR, &val);
+
+			/* Should wait for clear operation to finish */
+			while (val) {
+				regmap_read(i2s->regmap, I2S_CLR, &val);
+				retry--;
+				if (!retry)
+					dev_warn(i2s->dev, "fail to clear\n");
+			}
+		}
+	}
+}
+
+static int rockchip_i2s_set_fmt(struct snd_soc_dai *cpu_dai,
+				unsigned int fmt)
+{
+	struct rk_i2s_dev *i2s = to_info(cpu_dai);
+	unsigned int mask = 0, val = 0;
+
+	mask = I2S_CKR_MSS_SLAVE;
+	switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
+	case SND_SOC_DAIFMT_CBS_CFS:
+		val = I2S_CKR_MSS_SLAVE;
+		break;
+	case SND_SOC_DAIFMT_CBM_CFM:
+		val = I2S_CKR_MSS_MASTER;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_update_bits(i2s->regmap, I2S_CKR, mask, val);
+
+	mask = I2S_TXCR_IBM_MASK;
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_RIGHT_J:
+		val = I2S_TXCR_IBM_RSJM;
+		break;
+	case SND_SOC_DAIFMT_LEFT_J:
+		val = I2S_TXCR_IBM_LSJM;
+		break;
+	case SND_SOC_DAIFMT_I2S:
+		val = I2S_TXCR_IBM_NORMAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_update_bits(i2s->regmap, I2S_TXCR, mask, val);
+
+	mask = I2S_RXCR_IBM_MASK;
+	switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
+	case SND_SOC_DAIFMT_RIGHT_J:
+		val = I2S_RXCR_IBM_RSJM;
+		break;
+	case SND_SOC_DAIFMT_LEFT_J:
+		val = I2S_RXCR_IBM_LSJM;
+		break;
+	case SND_SOC_DAIFMT_I2S:
+		val = I2S_RXCR_IBM_NORMAL;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_update_bits(i2s->regmap, I2S_RXCR, mask, val);
+
+	return 0;
+}
+
+static int rockchip_i2s_hw_params(struct snd_pcm_substream *substream,
+				  struct snd_pcm_hw_params *params,
+				  struct snd_soc_dai *dai)
+{
+	struct rk_i2s_dev *i2s = to_info(dai);
+	unsigned int val = 0;
+
+	switch (params_format(params)) {
+	case SNDRV_PCM_FORMAT_S8:
+		val |= I2S_TXCR_VDW(8);
+		break;
+	case SNDRV_PCM_FORMAT_S16_LE:
+		val |= I2S_TXCR_VDW(16);
+		break;
+	case SNDRV_PCM_FORMAT_S20_3LE:
+		val |= I2S_TXCR_VDW(20);
+		break;
+	case SNDRV_PCM_FORMAT_S24_LE:
+		val |= I2S_TXCR_VDW(24);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_update_bits(i2s->regmap, I2S_TXCR, I2S_TXCR_VDW_MASK, val);
+	regmap_update_bits(i2s->regmap, I2S_RXCR, I2S_RXCR_VDW_MASK, val);
+
+	if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK) {
+		dai->playback_dma_data = &i2s->playback_dma_data;
+		regmap_update_bits(i2s->regmap, I2S_DMACR, I2S_DMACR_TDL_MASK,
+				   I2S_DMACR_TDL(1) | I2S_DMACR_TDE_ENABLE);
+	} else {
+		dai->capture_dma_data = &i2s->capture_dma_data;
+		regmap_update_bits(i2s->regmap, I2S_DMACR, I2S_DMACR_RDL_MASK,
+				   I2S_DMACR_RDL(1) | I2S_DMACR_RDE_ENABLE);
+	}
+
+	return 0;
+}
+
+static int rockchip_i2s_trigger(struct snd_pcm_substream *substream,
+				int cmd, struct snd_soc_dai *dai)
+{
+	struct rk_i2s_dev *i2s = to_info(dai);
+	int ret = 0;
+
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+	case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+		if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+			rockchip_snd_rxctrl(i2s, 1);
+		else
+			rockchip_snd_txctrl(i2s, 1);
+		break;
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+		if (substream->stream == SNDRV_PCM_STREAM_CAPTURE)
+			rockchip_snd_rxctrl(i2s, 0);
+		else
+			rockchip_snd_txctrl(i2s, 0);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static int rockchip_i2s_set_sysclk(struct snd_soc_dai *cpu_dai, int clk_id,
+				   unsigned int freq, int dir)
+{
+	struct rk_i2s_dev *i2s = to_info(cpu_dai);
+	int ret;
+
+	ret = clk_set_rate(i2s->mclk, freq);
+	if (ret)
+		dev_err(i2s->dev, "Fail to set mclk %d\n", ret);
+
+	return ret;
+}
+
+static const struct snd_soc_dai_ops rockchip_i2s_dai_ops = {
+	.hw_params = rockchip_i2s_hw_params,
+	.set_sysclk = rockchip_i2s_set_sysclk,
+	.set_fmt = rockchip_i2s_set_fmt,
+	.trigger = rockchip_i2s_trigger,
+};
+
+static struct snd_soc_dai_driver rockchip_i2s_dai = {
+	.playback = {
+		.channels_min = 2,
+		.channels_max = 8,
+		.rates = SNDRV_PCM_RATE_8000_192000,
+		.formats = (SNDRV_PCM_FMTBIT_S8 |
+			    SNDRV_PCM_FMTBIT_S16_LE |
+			    SNDRV_PCM_FMTBIT_S20_3LE |
+			    SNDRV_PCM_FMTBIT_S24_LE),
+	},
+	.capture = {
+		.channels_min = 2,
+		.channels_max = 2,
+		.rates = SNDRV_PCM_RATE_8000_192000,
+		.formats = (SNDRV_PCM_FMTBIT_S8 |
+			    SNDRV_PCM_FMTBIT_S16_LE |
+			    SNDRV_PCM_FMTBIT_S20_3LE |
+			    SNDRV_PCM_FMTBIT_S24_LE),
+	},
+	.ops = &rockchip_i2s_dai_ops,
+};
+
+static const struct snd_soc_component_driver rockchip_i2s_component = {
+	.name = DRV_NAME,
+};
+
+static bool rockchip_i2s_wr_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case I2S_TXCR:
+	case I2S_RXCR:
+	case I2S_CKR:
+	case I2S_DMACR:
+	case I2S_INTCR:
+	case I2S_XFER:
+	case I2S_CLR:
+	case I2S_TXDR:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool rockchip_i2s_rd_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case I2S_TXCR:
+	case I2S_RXCR:
+	case I2S_CKR:
+	case I2S_DMACR:
+	case I2S_INTCR:
+	case I2S_XFER:
+	case I2S_CLR:
+	case I2S_RXDR:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool rockchip_i2s_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case I2S_FIFOLR:
+	case I2S_INTSR:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool rockchip_i2s_precious_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case I2S_FIFOLR:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config rockchip_i2s_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = I2S_RXDR,
+	.writeable_reg = rockchip_i2s_wr_reg,
+	.readable_reg = rockchip_i2s_rd_reg,
+	.volatile_reg = rockchip_i2s_volatile_reg,
+	.precious_reg = rockchip_i2s_precious_reg,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static int rockchip_i2s_probe(struct platform_device *pdev)
+{
+	struct rk_i2s_dev *i2s;
+	struct resource *res;
+	void __iomem *regs;
+	int ret;
+
+	i2s = devm_kzalloc(&pdev->dev, sizeof(*i2s), GFP_KERNEL);
+	if (!i2s) {
+		dev_err(&pdev->dev, "Can't allocate rk_i2s_dev\n");
+		return -ENOMEM;
+	}
+
+	/* try to prepare related clocks */
+	i2s->hclk = devm_clk_get(&pdev->dev, "i2s_hclk");
+	if (IS_ERR(i2s->hclk)) {
+		dev_err(&pdev->dev, "Can't retrieve i2s bus clock\n");
+		return PTR_ERR(i2s->hclk);
+	}
+
+	i2s->mclk = devm_clk_get(&pdev->dev, "i2s_clk");
+	if (IS_ERR(i2s->mclk)) {
+		dev_err(&pdev->dev, "Can't retrieve i2s master clock\n");
+		return PTR_ERR(i2s->mclk);
+	}
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(regs)) {
+		dev_err(&pdev->dev, "No memory resource\n");
+		return PTR_ERR(regs);
+	}
+
+	i2s->regmap = devm_regmap_init_mmio(&pdev->dev, regs,
+					    &rockchip_i2s_regmap_config);
+	if (IS_ERR(i2s->regmap)) {
+		dev_err(&pdev->dev,
+			"Failed to initialise managed register map\n");
+		return PTR_ERR(i2s->regmap);
+	}
+
+	i2s->playback_dma_data.addr = res->start + I2S_TXDR;
+	i2s->playback_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	i2s->playback_dma_data.maxburst = 16;
+
+	i2s->capture_dma_data.addr = res->start + I2S_RXDR;
+	i2s->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	i2s->capture_dma_data.maxburst = 16;
+
+	i2s->dev = &pdev->dev;
+	dev_set_drvdata(&pdev->dev, i2s);
+
+	pm_runtime_enable(&pdev->dev);
+	if (!pm_runtime_enabled(&pdev->dev)) {
+		ret = i2s_runtime_resume(&pdev->dev);
+		if (ret)
+			goto err_pm_disable;
+	}
+
+	ret = devm_snd_soc_register_component(&pdev->dev,
+					      &rockchip_i2s_component,
+					      &rockchip_i2s_dai, 1);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not register DAI\n");
+		goto err_suspend;
+	}
+
+	ret = snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
+	if (ret) {
+		dev_err(&pdev->dev, "Could not register PCM\n");
+		goto err_pcm_register;
+	}
+
+	return 0;
+
+err_pcm_register:
+	snd_dmaengine_pcm_unregister(&pdev->dev);
+err_suspend:
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		i2s_runtime_suspend(&pdev->dev);
+err_pm_disable:
+	pm_runtime_disable(&pdev->dev);
+
+	return ret;
+}
+
+static int rockchip_i2s_remove(struct platform_device *pdev)
+{
+	struct rk_i2s_dev *i2s = dev_get_drvdata(&pdev->dev);
+
+	pm_runtime_disable(&pdev->dev);
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		i2s_runtime_suspend(&pdev->dev);
+
+	clk_disable_unprepare(i2s->mclk);
+	clk_disable_unprepare(i2s->hclk);
+	snd_dmaengine_pcm_unregister(&pdev->dev);
+	snd_soc_unregister_component(&pdev->dev);
+
+	return 0;
+}
+
+static const struct of_device_id rockchip_i2s_match[] = {
+	{ .compatible = "rockchip,rk3066-i2s", },
+	{},
+};
+
+static const struct dev_pm_ops rockchip_i2s_pm_ops = {
+	SET_RUNTIME_PM_OPS(i2s_runtime_suspend, i2s_runtime_resume,
+			   NULL)
+};
+
+static struct platform_driver rockchip_i2s_driver = {
+	.probe = rockchip_i2s_probe,
+	.remove = rockchip_i2s_remove,
+	.driver = {
+		.name = DRV_NAME,
+		.owner = THIS_MODULE,
+		.of_match_table = of_match_ptr(rockchip_i2s_match),
+		.pm = &rockchip_i2s_pm_ops,
+	},
+};
+module_platform_driver(rockchip_i2s_driver);
+
+MODULE_DESCRIPTION("ROCKCHIP IIS ASoC Interface");
+MODULE_AUTHOR("jianqun <jay.xu@rock-chips.com>");
+MODULE_LICENSE("GPL v2");
+MODULE_ALIAS("platform:" DRV_NAME);
+MODULE_DEVICE_TABLE(of, rockchip_i2s_match);