ASoC: rockchip: add support for pdm controller

The Pulse Density Modulation Interface Controller (PDMC) is
a PDM interface controller and decoder that support PDM format.
It integrates a clock generator driving the PDM microphone
and embeds filters which decimate the incoming bit stream to
obtain most common audio rates.

Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Signed-off-by: Mark Brown <broonie@kernel.org>

1 files changed, 516 insertions, 0 deletions

diff --git a/sound/soc/rockchip/rockchip_pdm.c b/sound/soc/rockchip/rockchip_pdm.c
new file mode 100644
index 000000000000..c5ddeed97260
--- /dev/null
+++ b/sound/soc/rockchip/rockchip_pdm.c
@@ -0,0 +1,516 @@
+/*
+ * Rockchip PDM ALSA SoC Digital Audio Interface(DAI)  driver
+ *
+ * Copyright (C) 2017 Fuzhou Rockchip Electronics Co., Ltd
+ *
+ * This software is licensed under the terms of the GNU General Public
+ * License version 2, as published by the Free Software Foundation, and
+ * may be copied, distributed, and modified under those terms.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/clk.h>
+#include <linux/of.h>
+#include <linux/pm_runtime.h>
+#include <linux/regmap.h>
+#include <sound/dmaengine_pcm.h>
+#include <sound/pcm_params.h>
+
+#include "rockchip_pdm.h"
+
+#define PDM_DMA_BURST_SIZE	(16) /* size * width: 16*4 = 64 bytes */
+
+struct rk_pdm_dev {
+	struct device *dev;
+	struct clk *clk;
+	struct clk *hclk;
+	struct regmap *regmap;
+	struct snd_dmaengine_dai_dma_data capture_dma_data;
+};
+
+struct rk_pdm_clkref {
+	unsigned int sr;
+	unsigned int clk;
+};
+
+static struct rk_pdm_clkref clkref[] = {
+	{ 8000, 40960000 },
+	{ 11025, 56448000 },
+	{ 12000, 61440000 },
+};
+
+static unsigned int get_pdm_clk(unsigned int sr)
+{
+	unsigned int i, count, clk, div;
+
+	clk = 0;
+	if (!sr)
+		return clk;
+
+	count = ARRAY_SIZE(clkref);
+	for (i = 0; i < count; i++) {
+		if (sr % clkref[i].sr)
+			continue;
+		div = sr / clkref[i].sr;
+		if ((div & (div - 1)) == 0) {
+			clk = clkref[i].clk;
+			break;
+		}
+	}
+
+	return clk;
+}
+
+static inline struct rk_pdm_dev *to_info(struct snd_soc_dai *dai)
+{
+	return snd_soc_dai_get_drvdata(dai);
+}
+
+static void rockchip_pdm_rxctrl(struct rk_pdm_dev *pdm, int on)
+{
+	if (on) {
+		regmap_update_bits(pdm->regmap, PDM_DMA_CTRL,
+				   PDM_DMA_RD_MSK, PDM_DMA_RD_EN);
+		regmap_update_bits(pdm->regmap, PDM_SYSCONFIG,
+				   PDM_RX_MASK, PDM_RX_START);
+	} else {
+		regmap_update_bits(pdm->regmap, PDM_DMA_CTRL,
+				   PDM_DMA_RD_MSK, PDM_DMA_RD_DIS);
+		regmap_update_bits(pdm->regmap, PDM_SYSCONFIG,
+				   PDM_RX_MASK | PDM_RX_CLR_MASK,
+				   PDM_RX_STOP | PDM_RX_CLR_WR);
+	}
+}
+
+static int rockchip_pdm_hw_params(struct snd_pcm_substream *substream,
+				  struct snd_pcm_hw_params *params,
+				  struct snd_soc_dai *dai)
+{
+	struct rk_pdm_dev *pdm = to_info(dai);
+	unsigned int val = 0;
+	unsigned int clk_rate, clk_div, samplerate;
+	int ret;
+
+	samplerate = params_rate(params);
+	clk_rate = get_pdm_clk(samplerate);
+	if (!clk_rate)
+		return -EINVAL;
+
+	ret = clk_set_rate(pdm->clk, clk_rate);
+	if (ret)
+		return -EINVAL;
+
+	clk_div = DIV_ROUND_CLOSEST(clk_rate, samplerate);
+
+	switch (clk_div) {
+	case 320:
+		val = PDM_CLK_320FS;
+		break;
+	case 640:
+		val = PDM_CLK_640FS;
+		break;
+	case 1280:
+		val = PDM_CLK_1280FS;
+		break;
+	case 2560:
+		val = PDM_CLK_2560FS;
+		break;
+	case 5120:
+		val = PDM_CLK_5120FS;
+		break;
+	default:
+		dev_err(pdm->dev, "unsupported div: %d\n", clk_div);
+		return -EINVAL;
+	}
+
+	regmap_update_bits(pdm->regmap, PDM_CLK_CTRL, PDM_DS_RATIO_MSK, val);
+	regmap_update_bits(pdm->regmap, PDM_HPF_CTRL,
+			   PDM_HPF_CF_MSK, PDM_HPF_60HZ);
+	regmap_update_bits(pdm->regmap, PDM_HPF_CTRL,
+			   PDM_HPF_LE | PDM_HPF_RE, PDM_HPF_LE | PDM_HPF_RE);
+	regmap_update_bits(pdm->regmap, PDM_CLK_CTRL, PDM_CLK_EN, PDM_CLK_EN);
+
+	val = 0;
+	switch (params_format(params)) {
+	case SNDRV_PCM_FORMAT_S8:
+		val |= PDM_VDW(8);
+		break;
+	case SNDRV_PCM_FORMAT_S16_LE:
+		val |= PDM_VDW(16);
+		break;
+	case SNDRV_PCM_FORMAT_S20_3LE:
+		val |= PDM_VDW(20);
+		break;
+	case SNDRV_PCM_FORMAT_S24_LE:
+		val |= PDM_VDW(24);
+		break;
+	case SNDRV_PCM_FORMAT_S32_LE:
+		val |= PDM_VDW(32);
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	switch (params_channels(params)) {
+	case 8:
+		val |= PDM_PATH3_EN;
+		/* fallthrough */
+	case 6:
+		val |= PDM_PATH2_EN;
+		/* fallthrough */
+	case 4:
+		val |= PDM_PATH1_EN;
+		/* fallthrough */
+	case 2:
+		val |= PDM_PATH0_EN;
+		break;
+	default:
+		dev_err(pdm->dev, "invalid channel: %d\n",
+			params_channels(params));
+		return -EINVAL;
+	}
+
+	if (substream->stream == SNDRV_PCM_STREAM_CAPTURE) {
+		regmap_update_bits(pdm->regmap, PDM_CTRL0,
+				   PDM_PATH_MSK | PDM_VDW_MSK,
+				   val);
+		regmap_update_bits(pdm->regmap, PDM_DMA_CTRL, PDM_DMA_RDL_MSK,
+				   PDM_DMA_RDL(16));
+		regmap_update_bits(pdm->regmap, PDM_SYSCONFIG,
+				   PDM_RX_MASK | PDM_RX_CLR_MASK,
+				   PDM_RX_STOP | PDM_RX_CLR_WR);
+	}
+
+	return 0;
+}
+
+static int rockchip_pdm_set_fmt(struct snd_soc_dai *cpu_dai,
+				unsigned int fmt)
+{
+	struct rk_pdm_dev *pdm = to_info(cpu_dai);
+	unsigned int mask = 0, val = 0;
+
+	mask = PDM_CKP_MSK;
+	switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
+	case SND_SOC_DAIFMT_NB_NF:
+		val = PDM_CKP_NORMAL;
+		break;
+	case SND_SOC_DAIFMT_IB_NF:
+		val = PDM_CKP_INVERTED;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	regmap_update_bits(pdm->regmap, PDM_CLK_CTRL, mask, val);
+
+	return 0;
+}
+
+static int rockchip_pdm_trigger(struct snd_pcm_substream *substream, int cmd,
+				struct snd_soc_dai *dai)
+{
+	struct rk_pdm_dev *pdm = 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_pdm_rxctrl(pdm, 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_pdm_rxctrl(pdm, 0);
+		break;
+	default:
+		ret = -EINVAL;
+		break;
+	}
+
+	return ret;
+}
+
+static int rockchip_pdm_dai_probe(struct snd_soc_dai *dai)
+{
+	struct rk_pdm_dev *pdm = to_info(dai);
+
+	dai->capture_dma_data = &pdm->capture_dma_data;
+
+	return 0;
+}
+
+static struct snd_soc_dai_ops rockchip_pdm_dai_ops = {
+	.set_fmt = rockchip_pdm_set_fmt,
+	.trigger = rockchip_pdm_trigger,
+	.hw_params = rockchip_pdm_hw_params,
+};
+
+#define ROCKCHIP_PDM_RATES SNDRV_PCM_RATE_8000_192000
+#define ROCKCHIP_PDM_FORMATS (SNDRV_PCM_FMTBIT_S16_LE | \
+			      SNDRV_PCM_FMTBIT_S20_3LE | \
+			      SNDRV_PCM_FMTBIT_S24_LE | \
+			      SNDRV_PCM_FMTBIT_S32_LE)
+
+static struct snd_soc_dai_driver rockchip_pdm_dai = {
+	.probe = rockchip_pdm_dai_probe,
+	.capture = {
+		.stream_name = "Capture",
+		.channels_min = 2,
+		.channels_max = 8,
+		.rates = ROCKCHIP_PDM_RATES,
+		.formats = ROCKCHIP_PDM_FORMATS,
+	},
+	.ops = &rockchip_pdm_dai_ops,
+	.symmetric_rates = 1,
+};
+
+static const struct snd_soc_component_driver rockchip_pdm_component = {
+	.name = "rockchip-pdm",
+};
+
+static int rockchip_pdm_runtime_suspend(struct device *dev)
+{
+	struct rk_pdm_dev *pdm = dev_get_drvdata(dev);
+
+	clk_disable_unprepare(pdm->clk);
+	clk_disable_unprepare(pdm->hclk);
+
+	return 0;
+}
+
+static int rockchip_pdm_runtime_resume(struct device *dev)
+{
+	struct rk_pdm_dev *pdm = dev_get_drvdata(dev);
+	int ret;
+
+	ret = clk_prepare_enable(pdm->clk);
+	if (ret) {
+		dev_err(pdm->dev, "clock enable failed %d\n", ret);
+		return ret;
+	}
+
+	ret = clk_prepare_enable(pdm->hclk);
+	if (ret) {
+		dev_err(pdm->dev, "hclock enable failed %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+static bool rockchip_pdm_wr_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case PDM_SYSCONFIG:
+	case PDM_CTRL0:
+	case PDM_CTRL1:
+	case PDM_CLK_CTRL:
+	case PDM_HPF_CTRL:
+	case PDM_FIFO_CTRL:
+	case PDM_DMA_CTRL:
+	case PDM_INT_EN:
+	case PDM_INT_CLR:
+	case PDM_DATA_VALID:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool rockchip_pdm_rd_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case PDM_SYSCONFIG:
+	case PDM_CTRL0:
+	case PDM_CTRL1:
+	case PDM_CLK_CTRL:
+	case PDM_HPF_CTRL:
+	case PDM_FIFO_CTRL:
+	case PDM_DMA_CTRL:
+	case PDM_INT_EN:
+	case PDM_INT_CLR:
+	case PDM_INT_ST:
+	case PDM_DATA_VALID:
+	case PDM_VERSION:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static bool rockchip_pdm_volatile_reg(struct device *dev, unsigned int reg)
+{
+	switch (reg) {
+	case PDM_SYSCONFIG:
+	case PDM_INT_CLR:
+	case PDM_INT_ST:
+		return true;
+	default:
+		return false;
+	}
+}
+
+static const struct regmap_config rockchip_pdm_regmap_config = {
+	.reg_bits = 32,
+	.reg_stride = 4,
+	.val_bits = 32,
+	.max_register = PDM_VERSION,
+	.writeable_reg = rockchip_pdm_wr_reg,
+	.readable_reg = rockchip_pdm_rd_reg,
+	.volatile_reg = rockchip_pdm_volatile_reg,
+	.cache_type = REGCACHE_FLAT,
+};
+
+static int rockchip_pdm_probe(struct platform_device *pdev)
+{
+	struct rk_pdm_dev *pdm;
+	struct resource *res;
+	void __iomem *regs;
+	int ret;
+
+	pdm = devm_kzalloc(&pdev->dev, sizeof(*pdm), GFP_KERNEL);
+	if (!pdm)
+		return -ENOMEM;
+
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	regs = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(regs))
+		return PTR_ERR(regs);
+
+	pdm->regmap = devm_regmap_init_mmio(&pdev->dev, regs,
+					    &rockchip_pdm_regmap_config);
+	if (IS_ERR(pdm->regmap))
+		return PTR_ERR(pdm->regmap);
+
+	pdm->capture_dma_data.addr = res->start + PDM_RXFIFO_DATA;
+	pdm->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+	pdm->capture_dma_data.maxburst = PDM_DMA_BURST_SIZE;
+
+	pdm->dev = &pdev->dev;
+	dev_set_drvdata(&pdev->dev, pdm);
+
+	pdm->clk = devm_clk_get(&pdev->dev, "pdm_clk");
+	if (IS_ERR(pdm->clk))
+		return PTR_ERR(pdm->clk);
+
+	pdm->hclk = devm_clk_get(&pdev->dev, "pdm_hclk");
+	if (IS_ERR(pdm->hclk))
+		return PTR_ERR(pdm->hclk);
+
+	ret = clk_prepare_enable(pdm->hclk);
+	if (ret)
+		return ret;
+
+	pm_runtime_enable(&pdev->dev);
+	if (!pm_runtime_enabled(&pdev->dev)) {
+		ret = rockchip_pdm_runtime_resume(&pdev->dev);
+		if (ret)
+			goto err_pm_disable;
+	}
+
+	ret = devm_snd_soc_register_component(&pdev->dev,
+					      &rockchip_pdm_component,
+					      &rockchip_pdm_dai, 1);
+
+	if (ret) {
+		dev_err(&pdev->dev, "could not register dai: %d\n", ret);
+		goto err_suspend;
+	}
+
+	ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
+	if (ret) {
+		dev_err(&pdev->dev, "could not register pcm: %d\n", ret);
+		goto err_suspend;
+	}
+
+	return 0;
+
+err_suspend:
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		rockchip_pdm_runtime_suspend(&pdev->dev);
+err_pm_disable:
+	pm_runtime_disable(&pdev->dev);
+
+	clk_disable_unprepare(pdm->hclk);
+
+	return ret;
+}
+
+static int rockchip_pdm_remove(struct platform_device *pdev)
+{
+	struct rk_pdm_dev *pdm = dev_get_drvdata(&pdev->dev);
+
+	pm_runtime_disable(&pdev->dev);
+	if (!pm_runtime_status_suspended(&pdev->dev))
+		rockchip_pdm_runtime_suspend(&pdev->dev);
+
+	clk_disable_unprepare(pdm->clk);
+	clk_disable_unprepare(pdm->hclk);
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_SLEEP
+static int rockchip_pdm_suspend(struct device *dev)
+{
+	struct rk_pdm_dev *pdm = dev_get_drvdata(dev);
+
+	regcache_mark_dirty(pdm->regmap);
+
+	return 0;
+}
+
+static int rockchip_pdm_resume(struct device *dev)
+{
+	struct rk_pdm_dev *pdm = dev_get_drvdata(dev);
+	int ret;
+
+	ret = pm_runtime_get_sync(dev);
+	if (ret < 0)
+		return ret;
+
+	ret = regcache_sync(pdm->regmap);
+
+	pm_runtime_put(dev);
+
+	return ret;
+}
+#endif
+
+static const struct dev_pm_ops rockchip_pdm_pm_ops = {
+	SET_RUNTIME_PM_OPS(rockchip_pdm_runtime_suspend,
+			   rockchip_pdm_runtime_resume, NULL)
+	SET_SYSTEM_SLEEP_PM_OPS(rockchip_pdm_suspend, rockchip_pdm_resume)
+};
+
+static const struct of_device_id rockchip_pdm_match[] = {
+	{ .compatible = "rockchip,pdm", },
+	{},
+};
+MODULE_DEVICE_TABLE(of, rockchip_pdm_match);
+
+static struct platform_driver rockchip_pdm_driver = {
+	.probe  = rockchip_pdm_probe,
+	.remove = rockchip_pdm_remove,
+	.driver = {
+		.name = "rockchip-pdm",
+		.of_match_table = of_match_ptr(rockchip_pdm_match),
+		.pm = &rockchip_pdm_pm_ops,
+	},
+};
+
+module_platform_driver(rockchip_pdm_driver);
+
+MODULE_AUTHOR("Sugar <sugar.zhang@rock-chips.com>");
+MODULE_DESCRIPTION("Rockchip PDM Controller Driver");
+MODULE_LICENSE("GPL v2");