Re: [PATCH v5 04/10] ASoC: qcom: Add lpass CPU driver for codec dma control

From: Srinivas Kandagatla
Date: Tue Nov 23 2021 - 07:28:06 EST




On 18/11/2021 12:48, Srinivasa Rao Mandadapu wrote:
Add lpass cpu driver to support audio over codec dma for
ADSP bypass usecase.

Signed-off-by: Srinivasa Rao Mandadapu <srivasam@xxxxxxxxxxxxxx>
Co-developed-by: Venkata Prasad Potturu <potturu@xxxxxxxxxxxxxx>
Signed-off-by: Venkata Prasad Potturu <potturu@xxxxxxxxxxxxxx>
---
sound/soc/qcom/lpass-cdc-dma.c | 195 +++++++++++++++++++++++++++++++++++++++++
sound/soc/qcom/lpass.h | 1 +
2 files changed, 196 insertions(+)
create mode 100644 sound/soc/qcom/lpass-cdc-dma.c

diff --git a/sound/soc/qcom/lpass-cdc-dma.c b/sound/soc/qcom/lpass-cdc-dma.c
new file mode 100644
index 0000000..f5bfda9
--- /dev/null
+++ b/sound/soc/qcom/lpass-cdc-dma.c
@@ -0,0 +1,195 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright (c) 2021 The Linux Foundation. All rights reserved.
+ *
+ * lpass-cdc-dma.c -- ALSA SoC WCD -CPU DAI driver for QTi LPASS WCD
+ */
+
+#include <linux/clk.h>
+#include <linux/module.h>
+#include <sound/soc.h>
+#include <sound/soc-dai.h>
+
+#include "lpass-lpaif-reg.h"
+#include "lpass.h"
+
+static void __get_dmactl_handle(struct snd_pcm_substream *substream, struct snd_soc_dai *dai,
+ struct lpaif_dmactl **dmactl, int *id)

Please rename this with an lpass prefix, Also indentation looks bit off here.

+{
+ struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
+ struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(soc_runtime, 0);
+ struct lpass_data *drvdata = snd_soc_dai_get_drvdata(dai);
+ struct snd_pcm_runtime *rt = substream->runtime;
+ struct lpass_pcm_data *pcm_data = rt->private_data;
+ struct lpass_variant *v = drvdata->variant;
+ int dir = substream->stream;
+ unsigned int dai_id = cpu_dai->driver->id;
+
+ if (dir == SNDRV_PCM_STREAM_PLAYBACK) {
+ *dmactl = drvdata->rxtx_rd_dmactl;
+ *id = pcm_data->dma_ch;
+ } else {
+ if (dai_id == LPASS_CDC_DMA_TX3) {
+ *dmactl = drvdata->rxtx_wr_dmactl;
+ *id = pcm_data->dma_ch - v->rxtx_wrdma_channel_start;
+ } else if (dai_id == LPASS_CDC_DMA_VA_TX0) {
+ *dmactl = drvdata->va_wr_dmactl;
+ *id = pcm_data->dma_ch - v->va_wrdma_channel_start;
+ }

use switch case here, also something like this makes more sense rather that just dealing with TX3 and VA TX0

switch (dai_id) {
case: LPASS_CDC_DMA_RX0 ... LPASS_CDC_DMA_RX8:
*dmactl = drvdata->rxtx_wr_dmactl;
*id = pcm_data->dma_ch;
break;
case: LPASS_CDC_DMA_TX0 ... LPASS_CDC_DMA_TX8:
*dmactl = drvdata->rxtx_wr_dmactl;
*id = pcm_data->dma_ch - v->rxtx_wrdma_channel_start;
break;
case LPASS_CDC_DMA_VA_TX0 ... LPASS_CDC_DMA_VA_TX8:
*dmactl = drvdata->rxtx_wr_dmactl;
*id = pcm_data->dma_ch - v->va_wrdma_channel_start;
break;
default:
dev_err(dev, "Invalid dai id for dma ctl\n");
break;
}

+ }
+}
+
+static int __lpass_platform_codec_intf_init(struct snd_soc_dai *dai,
+ struct snd_pcm_substream *substream)

Indentation is off, I think most of the code has simillar issue.

+{
+ struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
+ struct snd_soc_dai *cpu_dai = asoc_rtd_to_cpu(soc_runtime, 0);
+ struct lpaif_dmactl *dmactl;
+ int dir = substream->stream;
+ int ret, id, codec_intf;
+ unsigned int dai_id = cpu_dai->driver->id;
+
+ if (dir == SNDRV_PCM_STREAM_PLAYBACK)
+ codec_intf = LPASS_CDC_DMA_RX0_INTERFACE;

Why are we limiting this to just RX0, it should be trivial to add support to other RX and TX dais.

Add a helper to convert the dai ids to interface indexs

+ else
+ codec_intf = LPASS_CDC_DMA_INTERFACE(dai_id);
+
+ __get_dmactl_handle(substream, dai, &dmactl, &id);

We are not checking if dmactl is valid or not, best is to have a error returned from __get_dmactl_handle() and handle it properly here.
+
+ ret = regmap_fields_write(dmactl->codec_intf, id, codec_intf);
+ if (ret) {
+ dev_err(soc_runtime->dev,
Why not use a local declare a local dev pointer and use it here, it will save lines here.
+ "error writing to dmactl codec_intf reg field: %d\n", ret);
+ return ret;
+ }
+ ret = regmap_fields_write(dmactl->codec_fs_sel, id, 0x0);
+ if (ret) {
+ dev_err(soc_runtime->dev,
+ "error writing to dmactl codec_fs_sel reg field: %d\n", ret);
+ return ret;
+ }
+ ret = regmap_fields_write(dmactl->codec_fs_delay, id, 0x0);
+ if (ret) {
+ dev_err(soc_runtime->dev,
+ "error writing to dmactl codec_fs_delay reg field: %d\n", ret);
+ return ret;
+ }
+ ret = regmap_fields_write(dmactl->codec_pack, id, 0x1);
+ if (ret) {
+ dev_err(soc_runtime->dev,
+ "error writing to dmactl codec_pack reg field: %d\n", ret);
+ return ret;
+ }
+ ret = regmap_fields_write(dmactl->codec_enable, id, LPAIF_DMACTL_ENABLE_ON);
+ if (ret) {
+ dev_err(soc_runtime->dev,
+ "error writing to dmactl codec_enable reg field: %d\n", ret);
+ return ret;
+ }
+ return 0;
+}
+
+static int lpass_wcd_daiops_startup(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct lpass_data *drvdata = snd_soc_dai_get_drvdata(dai);
+ int ret;
+
+ ret = clk_bulk_prepare_enable(drvdata->cdc_num_clks, drvdata->cdc_clks);
+ if (ret) {
+ dev_err(dai->dev, "error in enabling cdc dma clks: %d\n", ret);
+ return ret;
+ }
+
+ return 0;

may be just do
return clk_bulk_prepare_enable(drvdata->cdc_num_clks, drvdata->cdc_clks);

soc_dai_ret() should print an error if startup fails.



+}
+
+static void lpass_wcd_daiops_shutdown(struct snd_pcm_substream *substream,
+ struct snd_soc_dai *dai)
+{
+ struct lpass_data *drvdata = snd_soc_dai_get_drvdata(dai);
+
+ clk_bulk_disable_unprepare(drvdata->cdc_num_clks, drvdata->cdc_clks);
+}
+
+static int lpass_wcd_daiops_hw_params(struct snd_pcm_substream *substream,
+ struct snd_pcm_hw_params *params, struct snd_soc_dai *dai)
+{
+ struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
+ struct lpaif_dmactl *dmactl;
+ unsigned int ret, regval;
+ unsigned int channels = params_channels(params);
+ int id;
+
+ __get_dmactl_handle(substream, dai, &dmactl, &id);

may be move it after switch case and handle the errors.
+
+ switch (channels) {
+ case 1:
+ regval = LPASS_CDC_DMA_INTF_ONE_CHANNEL;
+ break;
+ case 2:
+ regval = LPASS_CDC_DMA_INTF_TWO_CHANNEL;
+ break;
+ case 4:
+ regval = LPASS_CDC_DMA_INTF_FOUR_CHANNEL;
+ break;
+ case 6:
+ regval = LPASS_CDC_DMA_INTF_SIX_CHANNEL;
+ break;
+ case 8:
+ regval = LPASS_CDC_DMA_INTF_EIGHT_CHANNEL;
+ break;
+ default:
+ dev_err(soc_runtime->dev, "invalid PCM config\n");
+ return -EINVAL;
+ }
+
+ ret = regmap_fields_write(dmactl->codec_channel, id, regval);
+ if (ret) {
+ dev_err(soc_runtime->dev,
+ "error writing to dmactl codec_channel reg field: %d\n", ret);
+ return ret;
+ }
+ return 0;
+}
+
+static int lpass_wcd_daiops_trigger(struct snd_pcm_substream *substream,
+ int cmd, struct snd_soc_dai *dai)
+{
+ struct snd_soc_pcm_runtime *soc_runtime = asoc_substream_to_rtd(substream);
+ struct lpaif_dmactl *dmactl;
+ int ret = 0, id;
+
+ __get_dmactl_handle(substream, dai, &dmactl, &id);

move it inside the case where this is really used.

+
+ switch (cmd) {
+ case SNDRV_PCM_TRIGGER_START:
+ case SNDRV_PCM_TRIGGER_RESUME:
+ case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
+ __lpass_platform_codec_intf_init(dai, substream);
+ break;
+ case SNDRV_PCM_TRIGGER_STOP:
+ case SNDRV_PCM_TRIGGER_SUSPEND:
+ case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
+ ret = regmap_fields_write(dmactl->codec_enable, id, LPAIF_DMACTL_ENABLE_OFF);
+ if (ret) {
+ dev_err(soc_runtime->dev,
+ "error writing to dmactl codec_enable reg: %d\n", ret);
+ return ret;
+ }
+
+ break;

missing default:

+ }
+ return ret;
+}
+
+const struct snd_soc_dai_ops asoc_qcom_lpass_wcd_dai_ops = {
+ .startup = lpass_wcd_daiops_startup,
+ .shutdown = lpass_wcd_daiops_shutdown,
+ .hw_params = lpass_wcd_daiops_hw_params,
+ .trigger = lpass_wcd_daiops_trigger,
+};
+EXPORT_SYMBOL_GPL(asoc_qcom_lpass_wcd_dai_ops);
+
+MODULE_DESCRIPTION("QTi LPASS CDC DMA Driver");
+MODULE_LICENSE("GPL v2");

use
MODULE_LICENSE("GPL");

more info in ./Documentation/process/license-rules.rst

--srini
diff --git a/sound/soc/qcom/lpass.h b/sound/soc/qcom/lpass.h
index b068534..f912425 100644
--- a/sound/soc/qcom/lpass.h
+++ b/sound/soc/qcom/lpass.h
@@ -414,5 +414,6 @@ int asoc_qcom_lpass_cpu_dai_probe(struct snd_soc_dai *dai);
extern const struct snd_soc_dai_ops asoc_qcom_lpass_cpu_dai_ops;
int lpass_cpu_pcm_new(struct snd_soc_pcm_runtime *rtd,
struct snd_soc_dai *dai);
+extern const struct snd_soc_dai_ops asoc_qcom_lpass_wcd_dai_ops;
#endif /* __LPASS_H__ */