[RFC PATCH 4/4] ASoC: Intel: KMB: Enable DMA transfer mode
Michael Sit Wei Hong
michael.wei.hong.sit at intel.com
Tue Nov 17 09:03:52 CET 2020
Enable DMA transfer mode for Intel Keem Bay ASoC platform driver.
The driver will search the device tree for DMA resources at boot
time to enable DMA transfer mode, and will proceed to use DMA
transfer if the resource is available, otherwise the default PIO
mode will be used.
Due to DMA Block transfer limitation, a customized function is
introduced to check and handle the limitation. Instead of limiting
the maximum period bytes to the minimum supported, which forces the
period size to less than 10.6ms in the worst case, adjusting the DMA
to use a longer linked list will allow more flexible period sizes which
does not force applications to use ridiculously small period sizes.
Signed-off-by: Michael Sit Wei Hong <michael.wei.hong.sit at intel.com>
Reviewed-by: Pierre-Louis Bossart <pierre-louis.bossart at linux.intel.com>
---
sound/soc/intel/Kconfig | 2 +
sound/soc/intel/keembay/kmb_platform.c | 202 +++++++++++++++++++++++--
sound/soc/intel/keembay/kmb_platform.h | 9 ++
3 files changed, 198 insertions(+), 15 deletions(-)
diff --git a/sound/soc/intel/Kconfig b/sound/soc/intel/Kconfig
index a5b446d5af19..6114dadfc52f 100644
--- a/sound/soc/intel/Kconfig
+++ b/sound/soc/intel/Kconfig
@@ -200,6 +200,8 @@ config SND_SOC_INTEL_KEEMBAY
tristate "Keembay Platforms"
depends on ARM64 || COMPILE_TEST
depends on COMMON_CLK
+ select SND_DMAENGINE_PCM
+ select SND_SOC_GENERIC_DMAENGINE_PCM
help
If you have a Intel Keembay platform then enable this option
by saying Y or m.
diff --git a/sound/soc/intel/keembay/kmb_platform.c b/sound/soc/intel/keembay/kmb_platform.c
index 291a686568c2..3041823e447b 100644
--- a/sound/soc/intel/keembay/kmb_platform.c
+++ b/sound/soc/intel/keembay/kmb_platform.c
@@ -6,10 +6,12 @@
//
#include <linux/clk.h>
+#include <linux/dma-mapping.h>
#include <linux/io.h>
#include <linux/module.h>
#include <linux/of.h>
#include <linux/of_device.h>
+#include <sound/dmaengine_pcm.h>
#include <sound/pcm.h>
#include <sound/pcm_params.h>
#include <sound/soc.h>
@@ -23,6 +25,7 @@
#define I2S_OPERATION 0
#define DATA_WIDTH_CONFIG_BIT 6
#define TDM_CHANNEL_CONFIG_BIT 3
+#define MAX_DMA_BLOCKS 1024
static const struct snd_pcm_hardware kmb_pcm_hardware = {
.info = SNDRV_PCM_INFO_INTERLEAVED |
@@ -335,6 +338,45 @@ static snd_pcm_uframes_t kmb_pcm_pointer(struct snd_soc_component *component,
return pos < runtime->buffer_size ? pos : 0;
}
+static int kmb_pcm_prepare_and_submit(struct snd_pcm_substream *substream)
+{
+ struct dmaengine_pcm_runtime_data *prtd = substream_to_prtd(substream);
+ struct dma_chan *chan = prtd->dma_chan;
+ struct dma_async_tx_descriptor *desc;
+ enum dma_transfer_direction direction;
+ unsigned long flags = DMA_CTRL_ACK;
+ struct snd_pcm_runtime *runtime = substream->runtime;
+ int blocks;
+
+ blocks = bytes_to_samples(runtime, snd_pcm_lib_period_bytes(substream));
+ direction = snd_pcm_substream_to_dma_direction(substream);
+
+ if (!substream->runtime->no_period_wakeup)
+ flags |= DMA_PREP_INTERRUPT;
+
+ prtd->pos = 0;
+ /* Check if the number of blocks used exceed the DMA BLOCK limitation */
+ if (blocks > MAX_DMA_BLOCKS && direction == DMA_DEV_TO_MEM)
+ desc = dmaengine_prep_dma_cyclic(chan,
+ substream->runtime->dma_addr,
+ snd_pcm_lib_buffer_bytes(substream),
+ samples_to_bytes(runtime, MAX_DMA_BLOCKS), direction, flags);
+ else
+ desc = dmaengine_prep_dma_cyclic(chan,
+ substream->runtime->dma_addr,
+ snd_pcm_lib_buffer_bytes(substream),
+ snd_pcm_lib_period_bytes(substream), direction, flags);
+
+ if (!desc)
+ return -ENOMEM;
+
+ desc->callback = dmaengine_pcm_dma_complete;
+ desc->callback_param = substream;
+ prtd->cookie = dmaengine_submit(desc);
+
+ return 0;
+}
+
static const struct snd_soc_component_driver kmb_component = {
.name = "kmb",
.pcm_construct = kmb_platform_pcm_new,
@@ -343,6 +385,53 @@ static const struct snd_soc_component_driver kmb_component = {
.pointer = kmb_pcm_pointer,
};
+static const struct snd_soc_component_driver kmb_component_dma = {
+ .name = "kmb",
+};
+
+static int kmb_probe(struct snd_soc_dai *cpu_dai)
+{
+ struct kmb_i2s_info *kmb_i2s = snd_soc_dai_get_drvdata(cpu_dai);
+
+ if (kmb_i2s->use_pio)
+ return 0;
+
+ snd_soc_dai_init_dma_data(cpu_dai, &kmb_i2s->play_dma_data,
+ &kmb_i2s->capture_dma_data);
+
+ return 0;
+}
+
+static inline void kmb_i2s_enable_dma(struct kmb_i2s_info *kmb_i2s, u32 stream)
+{
+ u32 dma_reg;
+
+ dma_reg = readl(kmb_i2s->i2s_base + I2S_DMACR);
+ /* Enable DMA handshake for stream */
+ if (stream == SNDRV_PCM_STREAM_PLAYBACK)
+ dma_reg |= I2S_DMAEN_TXBLOCK;
+ else
+ dma_reg |= I2S_DMAEN_RXBLOCK;
+
+ writel(dma_reg, kmb_i2s->i2s_base + I2S_DMACR);
+}
+
+static inline void kmb_i2s_disable_dma(struct kmb_i2s_info *kmb_i2s, u32 stream)
+{
+ u32 dma_reg;
+
+ dma_reg = readl(kmb_i2s->i2s_base + I2S_DMACR);
+ /* Disable DMA handshake for stream */
+ if (stream == SNDRV_PCM_STREAM_PLAYBACK) {
+ dma_reg &= ~I2S_DMAEN_TXBLOCK;
+ writel(1, kmb_i2s->i2s_base + I2S_RTXDMA);
+ } else {
+ dma_reg &= ~I2S_DMAEN_RXBLOCK;
+ writel(1, kmb_i2s->i2s_base + I2S_RRXDMA);
+ }
+ writel(dma_reg, kmb_i2s->i2s_base + I2S_DMACR);
+}
+
static void kmb_i2s_start(struct kmb_i2s_info *kmb_i2s,
struct snd_pcm_substream *substream)
{
@@ -356,7 +445,11 @@ static void kmb_i2s_start(struct kmb_i2s_info *kmb_i2s,
else
writel(1, kmb_i2s->i2s_base + IRER);
- kmb_i2s_irq_trigger(kmb_i2s, substream->stream, config->chan_nr, true);
+ if (kmb_i2s->use_pio)
+ kmb_i2s_irq_trigger(kmb_i2s, substream->stream,
+ config->chan_nr, true);
+ else
+ kmb_i2s_enable_dma(kmb_i2s, substream->stream);
if (kmb_i2s->master)
writel(1, kmb_i2s->i2s_base + CER);
@@ -434,7 +527,8 @@ static int kmb_dai_trigger(struct snd_pcm_substream *substream,
break;
case SNDRV_PCM_TRIGGER_STOP:
kmb_i2s->active--;
- kmb_i2s_stop(kmb_i2s, substream);
+ if (kmb_i2s->use_pio)
+ kmb_i2s_stop(kmb_i2s, substream);
break;
default:
return -EINVAL;
@@ -485,16 +579,22 @@ static int kmb_dai_hw_params(struct snd_pcm_substream *substream,
config->data_width = 16;
kmb_i2s->ccr = 0x00;
kmb_i2s->xfer_resolution = 0x02;
+ kmb_i2s->play_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
+ kmb_i2s->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_2_BYTES;
break;
case SNDRV_PCM_FORMAT_S24_LE:
config->data_width = 32;
kmb_i2s->ccr = 0x14;
kmb_i2s->xfer_resolution = 0x05;
+ kmb_i2s->play_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ kmb_i2s->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
break;
case SNDRV_PCM_FORMAT_S32_LE:
config->data_width = 32;
kmb_i2s->ccr = 0x10;
kmb_i2s->xfer_resolution = 0x05;
+ kmb_i2s->play_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
+ kmb_i2s->capture_dma_data.addr_width = DMA_SLAVE_BUSWIDTH_4_BYTES;
break;
default:
dev_err(kmb_i2s->dev, "kmb: unsupported PCM fmt");
@@ -572,9 +672,56 @@ static int kmb_dai_prepare(struct snd_pcm_substream *substream,
return 0;
}
+static int kmb_dai_startup(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *cpu_dai)
+{
+ struct kmb_i2s_info *kmb_i2s = snd_soc_dai_get_drvdata(cpu_dai);
+ struct snd_dmaengine_dai_dma_data *dma_data;
+
+ if (kmb_i2s->use_pio)
+ return 0;
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+ dma_data = &kmb_i2s->play_dma_data;
+ else
+ dma_data = &kmb_i2s->capture_dma_data;
+
+ snd_soc_dai_set_dma_data(cpu_dai, substream, dma_data);
+
+ return 0;
+}
+
+static int kmb_dai_hw_free(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *cpu_dai)
+{
+ struct kmb_i2s_info *kmb_i2s = snd_soc_dai_get_drvdata(cpu_dai);
+ /* I2S Programming sequence in Keem_Bay_VPU_DB_v1.1 */
+ if (kmb_i2s->use_pio)
+ kmb_i2s_clear_irqs(kmb_i2s, substream->stream);
+
+ if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
+ writel(0, kmb_i2s->i2s_base + ITER);
+ else
+ writel(0, kmb_i2s->i2s_base + IRER);
+
+ if (kmb_i2s->use_pio)
+ kmb_i2s_irq_trigger(kmb_i2s, substream->stream, 8, false);
+ else
+ kmb_i2s_disable_dma(kmb_i2s, substream->stream);
+
+ if (!kmb_i2s->active) {
+ writel(0, kmb_i2s->i2s_base + CER);
+ writel(0, kmb_i2s->i2s_base + IER);
+ }
+
+ return 0;
+}
+
static struct snd_soc_dai_ops kmb_dai_ops = {
+ .startup = kmb_dai_startup,
.trigger = kmb_dai_trigger,
.hw_params = kmb_dai_hw_params,
+ .hw_free = kmb_dai_hw_free,
.prepare = kmb_dai_prepare,
.set_fmt = kmb_set_dai_fmt,
};
@@ -607,6 +754,7 @@ static struct snd_soc_dai_driver intel_kmb_i2s_dai[] = {
SNDRV_PCM_FMTBIT_S16_LE),
},
.ops = &kmb_dai_ops,
+ .probe = kmb_probe,
},
};
@@ -626,6 +774,7 @@ static struct snd_soc_dai_driver intel_kmb_tdm_dai[] = {
SNDRV_PCM_FMTBIT_S16_LE),
},
.ops = &kmb_dai_ops,
+ .probe = kmb_probe,
},
};
@@ -635,12 +784,19 @@ static const struct of_device_id kmb_plat_of_match[] = {
{}
};
+static const struct snd_dmaengine_pcm_config kmb_dmaengine_pcm_config = {
+ .prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
+ .custom_pcm_prepare_and_submit = kmb_pcm_prepare_and_submit,
+};
+
static int kmb_plat_dai_probe(struct platform_device *pdev)
{
+ struct device_node *np = pdev->dev.of_node;
struct snd_soc_dai_driver *kmb_i2s_dai;
const struct of_device_id *match;
struct device *dev = &pdev->dev;
struct kmb_i2s_info *kmb_i2s;
+ struct resource *res;
int ret, irq;
u32 comp1_reg;
@@ -682,7 +838,7 @@ static int kmb_plat_dai_probe(struct platform_device *pdev)
return PTR_ERR(kmb_i2s->clk_i2s);
}
- kmb_i2s->i2s_base = devm_platform_ioremap_resource(pdev, 0);
+ kmb_i2s->i2s_base = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
if (IS_ERR(kmb_i2s->i2s_base))
return PTR_ERR(kmb_i2s->i2s_base);
@@ -692,22 +848,38 @@ static int kmb_plat_dai_probe(struct platform_device *pdev)
kmb_i2s->dev = &pdev->dev;
- irq = platform_get_irq_optional(pdev, 0);
- if (irq > 0) {
- ret = devm_request_irq(dev, irq, kmb_i2s_irq_handler, 0,
- pdev->name, kmb_i2s);
- if (ret < 0) {
- dev_err(dev, "failed to request irq\n");
- return ret;
- }
- }
-
comp1_reg = readl(kmb_i2s->i2s_base + I2S_COMP_PARAM_1);
kmb_i2s->fifo_th = (1 << COMP1_FIFO_DEPTH(comp1_reg)) / 2;
- ret = devm_snd_soc_register_component(dev, &kmb_component,
- kmb_i2s_dai, 1);
+ kmb_i2s->use_pio = !(of_property_read_bool(np, "dmas"));
+
+ if (kmb_i2s->use_pio) {
+ irq = platform_get_irq_optional(pdev, 0);
+ if (irq > 0) {
+ ret = devm_request_irq(dev, irq, kmb_i2s_irq_handler, 0,
+ pdev->name, kmb_i2s);
+ if (ret < 0) {
+ dev_err(dev, "failed to request irq\n");
+ return ret;
+ }
+ }
+ ret = devm_snd_soc_register_component(dev, &kmb_component,
+ kmb_i2s_dai, 1);
+ } else {
+ kmb_i2s->play_dma_data.addr = res->start + I2S_TXDMA;
+ kmb_i2s->capture_dma_data.addr = res->start + I2S_RXDMA;
+ ret = snd_dmaengine_pcm_register(&pdev->dev,
+ &kmb_dmaengine_pcm_config, 0);
+ if (ret) {
+ dev_err(&pdev->dev, "could not register dmaengine: %d\n",
+ ret);
+ return ret;
+ }
+ ret = devm_snd_soc_register_component(dev, &kmb_component_dma,
+ kmb_i2s_dai, 1);
+ }
+
if (ret) {
dev_err(dev, "not able to register dai\n");
return ret;
diff --git a/sound/soc/intel/keembay/kmb_platform.h b/sound/soc/intel/keembay/kmb_platform.h
index 9756b132c12f..fd5341b66279 100644
--- a/sound/soc/intel/keembay/kmb_platform.h
+++ b/sound/soc/intel/keembay/kmb_platform.h
@@ -12,6 +12,7 @@
#include <linux/bits.h>
#include <linux/bitfield.h>
#include <linux/types.h>
+#include <sound/dmaengine_pcm.h>
/* Register values with reference to KMB databook v1.1 */
/* common register for all channel */
@@ -103,7 +104,12 @@
#define DW_I2S_MASTER BIT(3)
#define I2S_RXDMA 0x01C0
+#define I2S_RRXDMA 0x01C4
#define I2S_TXDMA 0x01C8
+#define I2S_RTXDMA 0x01CC
+#define I2S_DMACR 0x0200
+#define I2S_DMAEN_RXBLOCK (1 << 16)
+#define I2S_DMAEN_TXBLOCK (1 << 17)
/*
* struct i2s_clk_config_data - represent i2s clk configuration data
@@ -131,6 +137,9 @@ struct kmb_i2s_info {
u32 xfer_resolution;
u32 fifo_th;
bool master;
+ /* data related to DMA transfers b/w i2s and DMAC */
+ struct snd_dmaengine_dai_dma_data play_dma_data;
+ struct snd_dmaengine_dai_dma_data capture_dma_data;
struct i2s_clk_config_data config;
int (*i2s_clk_cfg)(struct i2s_clk_config_data *config);
--
2.17.1
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