[4/5,v4] ASoC: dwc: Add custom PCM driver

diff --git a/sound/soc/dwc/Kconfig b/sound/soc/dwc/Kconfig
index d50e085..2a21120 100644
--- a/sound/soc/dwc/Kconfig
+++ b/sound/soc/dwc/Kconfig
@@ -7,4 +7,13 @@  config SND_DESIGNWARE_I2S
 	 Synopsys desigwnware I2S device. The device supports upto
 	 maximum of 8 channels each for play and record.
 
+config SND_DESIGNWARE_PCM
+	tristate "Synopsys I2S PCM Driver"
+	help
+	 Say Y or M if you want to add support for ALSA ASoC platform driver
+	 using I2S.
+
+	 Select this option if you want to be able to create a sound interface
+	 using the I2S device driver as CPU driver. Instead of using ALSA
+	 DMA engine by selecting this driver a custom PCM driver will be used.
 
diff --git a/sound/soc/dwc/Makefile b/sound/soc/dwc/Makefile
index 319371f..1b48bccc 100644
--- a/sound/soc/dwc/Makefile
+++ b/sound/soc/dwc/Makefile
@@ -1,3 +1,4 @@ 
 # SYNOPSYS Platform Support
 obj-$(CONFIG_SND_DESIGNWARE_I2S) += designware_i2s.o
+obj-$(CONFIG_SND_DESIGNWARE_PCM) += designware_pcm.o
 
diff --git a/sound/soc/dwc/designware.h b/sound/soc/dwc/designware.h
new file mode 100644
index 0000000..196296c
--- /dev/null
+++ b/sound/soc/dwc/designware.h
@@ -0,0 +1,70 @@ 
+/*
+ * ALSA SoC Synopsys Audio Layer
+ *
+ * sound/soc/dwc/designware.h
+ *
+ * Copyright (C) 2016 Synopsys
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#ifndef __DESIGNWARE_H
+#define __DESIGNWARE_H
+
+#include <linux/clk.h>
+#include <linux/device.h>
+#include <sound/designware_i2s.h>
+#include <sound/dmaengine_pcm.h>
+
+struct dw_pcm_binfo {
+	struct snd_pcm_substream *stream;
+	unsigned char *dma_base;
+	unsigned char *dma_pointer;
+	unsigned int period_size_frames;
+	unsigned int size;
+	snd_pcm_uframes_t period_pointer;
+	unsigned int total_periods;
+	unsigned int current_period;
+};
+
+union dw_i2s_snd_dma_data {
+	struct i2s_dma_data pd;
+	struct snd_dmaengine_dai_dma_data dt;
+};
+
+struct dw_i2s_dev {
+	void __iomem *i2s_base;
+	struct clk *clk;
+	int active;
+	unsigned int capability;
+	unsigned int quirks;
+	unsigned int i2s_reg_comp1;
+	unsigned int i2s_reg_comp2;
+	struct device *dev;
+	u32 ccr;
+	u32 xfer_resolution;
+	u32 fifo_th;
+
+	/* data related to DMA transfers b/w i2s and DMAC */
+	bool use_dmaengine;
+	union dw_i2s_snd_dma_data play_dma_data;
+	union dw_i2s_snd_dma_data capture_dma_data;
+	struct i2s_clk_config_data config;
+	int (*i2s_clk_cfg)(struct i2s_clk_config_data *config);
+	struct dw_pcm_binfo binfo;
+};
+
+#ifdef CONFIG_SND_DESIGNWARE_PCM
+int dw_pcm_transfer(u32 *lsample, u32 *rsample, int bytes, int buf_size,
+		struct dw_pcm_binfo *bi);
+#else
+int dw_pcm_transfer(u32 *lsample, u32 *rsample, int bytes, int buf_size,
+		struct dw_pcm_binfo *bi)
+{
+	return 0;
+}
+#endif
+
+#endif
diff --git a/sound/soc/dwc/designware_i2s.c b/sound/soc/dwc/designware_i2s.c
index 0db69b7..16056c1 100644
--- a/sound/soc/dwc/designware_i2s.c
+++ b/sound/soc/dwc/designware_i2s.c
@@ -24,6 +24,7 @@ 
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
 #include <sound/dmaengine_pcm.h>
+#include "designware.h"
 
 /* common register for all channel */
 #define IER		0x000
@@ -84,31 +85,6 @@ 
 #define MAX_CHANNEL_NUM		8
 #define MIN_CHANNEL_NUM		2
 
-union dw_i2s_snd_dma_data {
-	struct i2s_dma_data pd;
-	struct snd_dmaengine_dai_dma_data dt;
-};
-
-struct dw_i2s_dev {
-	void __iomem *i2s_base;
-	struct clk *clk;
-	int active;
-	unsigned int capability;
-	unsigned int quirks;
-	unsigned int i2s_reg_comp1;
-	unsigned int i2s_reg_comp2;
-	struct device *dev;
-	u32 ccr;
-	u32 xfer_resolution;
-	u32 fifo_th;
-
-	/* data related to DMA transfers b/w i2s and DMAC */
-	union dw_i2s_snd_dma_data play_dma_data;
-	union dw_i2s_snd_dma_data capture_dma_data;
-	struct i2s_clk_config_data config;
-	int (*i2s_clk_cfg)(struct i2s_clk_config_data *config);
-};
-
 static inline void i2s_write_reg(void __iomem *io_base, int reg, u32 val)
 {
 	writel(val, io_base + reg);
@@ -145,6 +121,54 @@  static inline void i2s_clear_irqs(struct dw_i2s_dev *dev, u32 stream)
 	}
 }
 
+static irqreturn_t dw_i2s_irq_handler(int irq, void *dev_id)
+{
+	struct dw_i2s_dev *dev = dev_id;
+	u32 isr[4], sleft[dev->fifo_th], sright[dev->fifo_th];
+	int i, j, xfer_bytes = dev->config.data_width / 8;
+	int dir = dev->binfo.stream->stream;
+
+	for (i = 0; i < 4; i++)
+		isr[i] = i2s_read_reg(dev->i2s_base, ISR(i));
+
+	i2s_clear_irqs(dev, SNDRV_PCM_STREAM_PLAYBACK);
+	i2s_clear_irqs(dev, SNDRV_PCM_STREAM_CAPTURE);
+
+	if (dev->use_dmaengine)
+		return IRQ_HANDLED;
+
+	for (i = 0; i < 4; i++) {
+		/* Copy only to/from first two channels
+		 * TODO: Remaining channels
+		 */
+		if ((isr[i] & 0x10) && (i == 0) &&
+				(dir == SNDRV_PCM_STREAM_PLAYBACK)) {
+			/* TXFEM - TX FIFO is empty */
+			dw_pcm_transfer(sleft, sright, xfer_bytes, dev->fifo_th,
+					&dev->binfo);
+			for (j = 0; j < dev->fifo_th; j++) {
+				i2s_write_reg(dev->i2s_base, LRBR_LTHR(i),
+						sleft[j]);
+				i2s_write_reg(dev->i2s_base, RRBR_RTHR(i),
+						sright[j]);
+			}
+		} else if ((isr[i] & 0x01) && (i == 0) &&
+				(dir == SNDRV_PCM_STREAM_CAPTURE)) {
+			/* RXDAM - RX FIFO is full */
+			for (j = 0; j < dev->fifo_th; j++) {
+				sleft[j] = i2s_read_reg(dev->i2s_base,
+						LRBR_LTHR(i));
+				sright[j] = i2s_read_reg(dev->i2s_base,
+						RRBR_RTHR(i));
+			}
+			dw_pcm_transfer(sleft, sright, xfer_bytes, dev->fifo_th,
+					&dev->binfo);
+		}
+	}
+
+	return IRQ_HANDLED;
+}
+
 static void i2s_start(struct dw_i2s_dev *dev,
 		      struct snd_pcm_substream *substream)
 {
@@ -626,7 +650,7 @@  static int dw_i2s_probe(struct platform_device *pdev)
 	const struct i2s_platform_data *pdata = pdev->dev.platform_data;
 	struct dw_i2s_dev *dev;
 	struct resource *res;
-	int ret;
+	int ret, irq_number;
 	struct snd_soc_dai_driver *dw_i2s_dai;
 	const char *clk_id;
 
@@ -649,6 +673,24 @@  static int dw_i2s_probe(struct platform_device *pdev)
 	if (IS_ERR(dev->i2s_base))
 		return PTR_ERR(dev->i2s_base);
 
+	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
+	dev->i2s_base = devm_ioremap_resource(&pdev->dev, res);
+	if (IS_ERR(dev->i2s_base))
+		return PTR_ERR(dev->i2s_base);
+
+	irq_number = platform_get_irq(pdev, 0);
+	if (irq_number <= 0) {
+		dev_err(&pdev->dev, "get_irq fail\n");
+		return -EINVAL;
+	}
+
+	ret = devm_request_irq(&pdev->dev, irq_number, dw_i2s_irq_handler,
+			IRQF_SHARED, "dw_i2s_irq_handler", dev);
+	if (ret < 0) {
+		dev_err(&pdev->dev, "request_irq fail\n");
+		return ret;
+	}
+
 	dev->dev = &pdev->dev;
 
 	dev->i2s_reg_comp1 = I2S_COMP_PARAM_1;
@@ -657,6 +699,7 @@  static int dw_i2s_probe(struct platform_device *pdev)
 		dev->capability = pdata->cap;
 		clk_id = NULL;
 		dev->quirks = pdata->quirks;
+		dev->use_dmaengine = false;
 		if (dev->quirks & DW_I2S_QUIRK_COMP_REG_OFFSET) {
 			dev->i2s_reg_comp1 = pdata->i2s_reg_comp1;
 			dev->i2s_reg_comp2 = pdata->i2s_reg_comp2;
@@ -664,6 +707,8 @@  static int dw_i2s_probe(struct platform_device *pdev)
 		ret = dw_configure_dai_by_pd(dev, dw_i2s_dai, res, pdata);
 	} else {
 		clk_id = "i2sclk";
+		dev->use_dmaengine = of_property_read_bool(pdev->dev.of_node,
+				"snps,use-dmaengine");
 		ret = dw_configure_dai_by_dt(dev, dw_i2s_dai, res);
 	}
 	if (ret < 0)
@@ -695,7 +740,7 @@  static int dw_i2s_probe(struct platform_device *pdev)
 		goto err_clk_disable;
 	}
 
-	if (!pdata) {
+	if (dev->use_dmaengine) {
 		ret = devm_snd_dmaengine_pcm_register(&pdev->dev, NULL, 0);
 		if (ret) {
 			dev_err(&pdev->dev,
diff --git a/sound/soc/dwc/designware_pcm.c b/sound/soc/dwc/designware_pcm.c
new file mode 100644
index 0000000..84ff6b9
--- /dev/null
+++ b/sound/soc/dwc/designware_pcm.c
@@ -0,0 +1,230 @@ 
+/*
+ * Synopsys I2S PCM Driver
+ *
+ * Copyright (C) 2016 Synopsys
+ *
+ * This file is licensed under the terms of the GNU General Public
+ * License version 2. This program is licensed "as is" without any
+ * warranty of any kind, whether express or implied.
+ */
+
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/platform_device.h>
+#include <linux/dmaengine.h>
+#include <linux/dma-mapping.h>
+#include <linux/slab.h>
+#include <sound/pcm.h>
+#include <sound/soc.h>
+#include <sound/dmaengine_pcm.h>
+#include "designware.h"
+
+#define BUFFER_BYTES_MAX	384000
+#define PERIOD_BYTES_MIN	2048
+#define PERIODS_MIN		8
+
+static const struct snd_pcm_hardware dw_pcm_hardware = {
+	.info = SNDRV_PCM_INFO_INTERLEAVED |
+		SNDRV_PCM_INFO_MMAP |
+		SNDRV_PCM_INFO_MMAP_VALID |
+		SNDRV_PCM_INFO_BLOCK_TRANSFER,
+	.rates = SNDRV_PCM_RATE_32000 |
+		SNDRV_PCM_RATE_44100 |
+		SNDRV_PCM_RATE_48000,
+	.rate_min = 32000,
+	.rate_max = 48000,
+	.formats = SNDRV_PCM_FMTBIT_S16_LE,
+	.channels_min = 2,
+	.channels_max = 2,
+	.buffer_bytes_max = BUFFER_BYTES_MAX,
+	.period_bytes_min = PERIOD_BYTES_MIN,
+	.period_bytes_max = BUFFER_BYTES_MAX / PERIODS_MIN,
+	.periods_min = PERIODS_MIN,
+	.periods_max = BUFFER_BYTES_MAX / PERIOD_BYTES_MIN,
+};
+
+int dw_pcm_transfer(u32 *lsample, u32 *rsample, int bytes, int buf_size,
+		struct dw_pcm_binfo *bi)
+{
+	struct snd_pcm_runtime *rt = bi->stream->runtime;
+	int dir = bi->stream->stream;
+	int i;
+
+	for (i = 0; i < buf_size; i++) {
+		if (dir == SNDRV_PCM_STREAM_PLAYBACK) {
+			memcpy(&lsample[i], bi->dma_pointer, bytes);
+			bi->dma_pointer += bytes;
+			memcpy(&rsample[i], bi->dma_pointer, bytes);
+			bi->dma_pointer += bytes;
+		} else {
+			memcpy(bi->dma_pointer, &lsample[i], bytes);
+			bi->dma_pointer += bytes;
+			memcpy(bi->dma_pointer, &rsample[i], bytes);
+			bi->dma_pointer += bytes;
+		}
+	}
+
+	bi->period_pointer += bytes_to_frames(rt, bytes * 2 * buf_size);
+
+	if (bi->period_pointer >= (bi->period_size_frames * bi->current_period)) {
+		bi->current_period++;
+		if (bi->current_period > bi->total_periods) {
+			bi->dma_pointer = bi->dma_base;
+			bi->period_pointer = 0;
+			bi->current_period = 1;
+		}
+		snd_pcm_period_elapsed(bi->stream);
+	}
+
+	return 0;
+}
+
+static int dw_pcm_open(struct snd_pcm_substream *substream)
+{
+	struct snd_soc_pcm_runtime *rtd = substream->private_data;
+	struct snd_pcm_runtime *rt = substream->runtime;
+	struct dw_i2s_dev *dev = snd_soc_dai_get_drvdata(rtd->cpu_dai);
+
+	snd_soc_set_runtime_hwparams(substream, &dw_pcm_hardware);
+	snd_pcm_hw_constraint_integer(rt, SNDRV_PCM_HW_PARAM_PERIODS);
+
+	dev->binfo.stream = substream;
+	rt->private_data = &dev->binfo;
+	return 0;
+}
+
+static int dw_pcm_close(struct snd_pcm_substream *substream)
+{
+	return 0;
+}
+
+static int dw_pcm_hw_params(struct snd_pcm_substream *substream,
+		struct snd_pcm_hw_params *hw_params)
+{
+	struct snd_pcm_runtime *rt = substream->runtime;
+	struct dw_pcm_binfo *bi = rt->private_data;
+	int ret;
+
+	ret = snd_pcm_lib_alloc_vmalloc_buffer(substream,
+			params_buffer_bytes(hw_params));
+	if (ret < 0)
+		return ret;
+
+	memset(rt->dma_area, 0, params_buffer_bytes(hw_params));
+	bi->dma_base = rt->dma_area;
+	bi->dma_pointer = bi->dma_base;
+
+	return 0;
+}
+
+static int dw_pcm_hw_free(struct snd_pcm_substream *substream)
+{
+	int ret;
+
+	ret = snd_pcm_lib_free_vmalloc_buffer(substream);
+	if (ret < 0)
+		return ret;
+	return 0;
+}
+
+static int dw_pcm_prepare(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *rt = substream->runtime;
+	struct dw_pcm_binfo *bi = rt->private_data;
+	u32 buffer_size_frames = 0;
+
+	bi->period_size_frames = bytes_to_frames(rt,
+			snd_pcm_lib_period_bytes(substream));
+	bi->size = snd_pcm_lib_buffer_bytes(substream);
+	buffer_size_frames = bytes_to_frames(rt, bi->size);
+	bi->total_periods = buffer_size_frames / bi->period_size_frames;
+	bi->current_period = 1;
+
+	if ((buffer_size_frames % bi->period_size_frames) != 0)
+		return -EINVAL;
+	return 0;
+}
+
+static int dw_pcm_trigger(struct snd_pcm_substream *substream, int cmd)
+{
+	switch (cmd) {
+	case SNDRV_PCM_TRIGGER_START:
+	case SNDRV_PCM_TRIGGER_RESUME:
+		break;
+	case SNDRV_PCM_TRIGGER_STOP:
+	case SNDRV_PCM_TRIGGER_SUSPEND:
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	return 0;
+}
+
+static snd_pcm_uframes_t dw_pcm_pointer(struct snd_pcm_substream *substream)
+{
+	struct snd_pcm_runtime *rt = substream->runtime;
+	struct dw_pcm_binfo *bi = rt->private_data;
+
+	return bi->period_pointer;
+}
+
+static struct snd_pcm_ops dw_pcm_ops = {
+	.open = dw_pcm_open,
+	.close = dw_pcm_close,
+	.ioctl = snd_pcm_lib_ioctl,
+	.hw_params = dw_pcm_hw_params,
+	.hw_free = dw_pcm_hw_free,
+	.prepare = dw_pcm_prepare,
+	.trigger = dw_pcm_trigger,
+	.pointer = dw_pcm_pointer,
+	.page = snd_pcm_lib_get_vmalloc_page,
+	.mmap = snd_pcm_lib_mmap_vmalloc,
+};
+
+static int dw_pcm_new(struct snd_soc_pcm_runtime *runtime)
+{
+	struct snd_pcm *pcm = runtime->pcm;
+
+	return snd_pcm_lib_preallocate_pages_for_all(pcm, SNDRV_DMA_TYPE_DEV,
+			snd_dma_continuous_data(GFP_KERNEL), BUFFER_BYTES_MAX,
+			BUFFER_BYTES_MAX);
+}
+
+static void dw_pcm_free(struct snd_pcm *pcm)
+{
+	snd_pcm_lib_preallocate_free_for_all(pcm);
+}
+
+static struct snd_soc_platform_driver dw_pcm_platform = {
+	.pcm_new = dw_pcm_new,
+	.pcm_free = dw_pcm_free,
+	.ops = &dw_pcm_ops,
+};
+
+static int dw_pcm_probe(struct platform_device *pdev)
+{
+	return devm_snd_soc_register_platform(&pdev->dev, &dw_pcm_platform);
+}
+
+#ifdef CONFIG_OF
+static const struct of_device_id dw_pcm_of[] = {
+	{ .compatible = "snps,designware-pcm" },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, dw_pcm_of);
+#endif
+
+static struct platform_driver dw_pcm_driver = {
+	.driver = {
+		.name = "designware-pcm",
+		.of_match_table = of_match_ptr(dw_pcm_of),
+	},
+	.probe = dw_pcm_probe,
+};
+
+module_platform_driver(dw_pcm_driver);
+
+MODULE_AUTHOR("Jose Abreu <joabreu@synopsys.com>, Tiago Duarte");
+MODULE_DESCRIPTION("Synopsys Designware PCM Driver");
+MODULE_LICENSE("GPL v2");