Re: [PATCH v2 3/3] ASoC: cros_ec_codec: Add codec driver for Cros EC

From: Guenter Roeck
Date: Mon Dec 24 2018 - 09:59:04 EST

On Mon, Dec 24, 2018 at 12:45 AM Cheng-Yi Chiang <cychiang@xxxxxxxxxxxx> wrote:
>
> Add a codec driver to control ChromeOS EC codec.
>
> Use EC Host command to enable/disable I2S recording and control other
> configurations.
>
> Signed-off-by: Cheng-Yi Chiang <cychiang@xxxxxxxxxxxx>
> ---
> Addressed Enric's comments.
>
> Changes in v2:
> - Many style fixes. Passed checkpatch.pl --strict.
> - Use ChromeOS naming.
> - Remove license boilerplate.
> - Use u8 instead of uint8_t.
> - Remove useless debug messages.
> - Remove useless remove ops.
> - Remove -EPROBE_DEFER in probe.
>
> MAINTAINERS | 2 +
> sound/soc/codecs/Kconfig | 8 +
> sound/soc/codecs/Makefile | 2 +
> sound/soc/codecs/cros_ec_codec.c | 458 +++++++++++++++++++++++++++++++
> sound/soc/codecs/cros_ec_codec.h | 21 ++
> 5 files changed, 491 insertions(+)
> create mode 100644 sound/soc/codecs/cros_ec_codec.c
> create mode 100644 sound/soc/codecs/cros_ec_codec.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 05e1922624e58..d66f80f3252d7 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -3638,8 +3638,10 @@ F: drivers/platform/chrome/
>
> CHROMEOS EC CODEC DRIVER
> M: Cheng-Yi Chiang <cychiang@xxxxxxxxxxxx>
> +R: Enric Balletbo i Serra <enric.balletbo@xxxxxxxxxxxxx>
> S: Maintained
> F: Documentation/devicetree/bindings/sound/google,cros-ec-codec.txt
> +F: sound/soc/codecs/cros_ec_codec.*
>
> CIRRUS LOGIC AUDIO CODEC DRIVERS
> M: Brian Austin <brian.austin@xxxxxxxxxx>
> diff --git a/sound/soc/codecs/Kconfig b/sound/soc/codecs/Kconfig
> index 87cb9c51e6f5a..0b36428159b71 100644
> --- a/sound/soc/codecs/Kconfig
> +++ b/sound/soc/codecs/Kconfig
> @@ -50,6 +50,7 @@ config SND_SOC_ALL_CODECS
> select SND_SOC_BT_SCO
> select SND_SOC_BD28623
> select SND_SOC_CQ0093VC
> + select SND_SOC_CROS_EC_CODEC
> select SND_SOC_CS35L32 if I2C
> select SND_SOC_CS35L33 if I2C
> select SND_SOC_CS35L34 if I2C
> @@ -457,6 +458,13 @@ config SND_SOC_CPCAP
> config SND_SOC_CQ0093VC
> tristate
>
> +config SND_SOC_CROS_EC_CODEC
> + tristate "codec driver for ChromeOS EC"
> + depends on MFD_CROS_EC
> + help
> + If you say yes here you will get support for the
> + ChromeOS Embedded Controller's Audio Codec.
> +
> config SND_SOC_CS35L32
> tristate "Cirrus Logic CS35L32 CODEC"
> depends on I2C
> diff --git a/sound/soc/codecs/Makefile b/sound/soc/codecs/Makefile
> index 9bb3346fab2fe..3cfd8f5f61705 100644
> --- a/sound/soc/codecs/Makefile
> +++ b/sound/soc/codecs/Makefile
> @@ -42,6 +42,7 @@ snd-soc-bd28623-objs := bd28623.o
> snd-soc-bt-sco-objs := bt-sco.o
> snd-soc-cpcap-objs := cpcap.o
> snd-soc-cq93vc-objs := cq93vc.o
> +snd-soc-cros-ec-codec-objs := cros_ec_codec.o
> snd-soc-cs35l32-objs := cs35l32.o
> snd-soc-cs35l33-objs := cs35l33.o
> snd-soc-cs35l34-objs := cs35l34.o
> @@ -310,6 +311,7 @@ obj-$(CONFIG_SND_SOC_BD28623) += snd-soc-bd28623.o
> obj-$(CONFIG_SND_SOC_BT_SCO) += snd-soc-bt-sco.o
> obj-$(CONFIG_SND_SOC_CQ0093VC) += snd-soc-cq93vc.o
> obj-$(CONFIG_SND_SOC_CPCAP) += snd-soc-cpcap.o
> +obj-$(CONFIG_SND_SOC_CROS_EC_CODEC) += snd-soc-cros-ec-codec.o
> obj-$(CONFIG_SND_SOC_CS35L32) += snd-soc-cs35l32.o
> obj-$(CONFIG_SND_SOC_CS35L33) += snd-soc-cs35l33.o
> obj-$(CONFIG_SND_SOC_CS35L34) += snd-soc-cs35l34.o
> diff --git a/sound/soc/codecs/cros_ec_codec.c b/sound/soc/codecs/cros_ec_codec.c
> new file mode 100644
> index 0000000000000..39e61bf46b5c0
> --- /dev/null
> +++ b/sound/soc/codecs/cros_ec_codec.c
> @@ -0,0 +1,458 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * Driver for ChromeOS Embedded Controller codec.
> + *
> + * This driver uses the cros-ec interface to communicate with the ChromeOS
> + * EC for audio function.
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/device.h>
> +#include <linux/kernel.h>
> +#include <linux/mfd/cros_ec.h>
> +#include <linux/mfd/cros_ec_commands.h>
> +#include <linux/module.h>
> +#include <linux/platform_device.h>
> +#include <sound/pcm.h>
> +#include <sound/pcm_params.h>
> +#include <sound/soc.h>
> +#include <sound/tlv.h>
> +
> +#include "cros_ec_codec.h"
> +
> +#define MAX_GAIN 43
> +
> +#define DRV_NAME "cros-ec-codec"
> +
> +static const DECLARE_TLV_DB_SCALE(ec_mic_gain_tlv, 0, 100, 0);
> +/*
> + * Wrapper for EC command.
> + */
> +static int ec_command(struct snd_soc_component *component, int version,
> + int command, u8 *outdata, int outsize,
> + u8 *indata, int insize)
> +{
> + struct cros_ec_codec_data *codec_data =
> + snd_soc_component_get_drvdata(component);
> + struct cros_ec_device *ec_device = codec_data->ec_device;
> + struct cros_ec_command *msg;
> + int ret;
> +
> + msg = kzalloc(sizeof(*msg) + max(insize, outsize), GFP_KERNEL);
> + if (!msg)
> + return -ENOMEM;
> +
> + msg->version = version;
> + msg->command = command;
> + msg->outsize = outsize;
> + msg->insize = insize;
> +
> + if (outsize)
> + memcpy(msg->data, outdata, outsize);
> +
> + ret = cros_ec_cmd_xfer_status(ec_device, msg);
> + if (ret > 0 && insize)
> + memcpy(indata, msg->data, insize);
> +
> + kfree(msg);
> + return ret;
> +}
> +
> +static int set_i2s_config(struct snd_soc_component *component,
> + enum ec_i2s_config i2s_config)
> +{
> + struct ec_param_codec_i2s param;
> + int ret;
> +
> + dev_dbg(component->dev, "%s set I2S format to %u\n", __func__,
> + i2s_config);
> +
> + param.cmd = EC_CODEC_I2S_SET_CONFIG;
> + param.i2s_config = i2s_config;
> +
> + ret = ec_command(component, 0, EC_CMD_CODEC_I2S,
> + (u8 *)&param, sizeof(param),
> + NULL, 0);
> + if (ret < 0) {
> + dev_err(component->dev,
> + "set I2S format to %u command returned %d\n",
> + i2s_config, ret);
> + return -EINVAL;

Overriding error codes is discouraged. You'll probably get a warning
from a static analyzer for this.

> + }
> + return 0;
> +}
> +
> +static int cros_ec_i2s_set_dai_fmt(struct snd_soc_dai *dai, unsigned int fmt)
> +{
> + struct snd_soc_component *component = dai->component;
> + enum ec_i2s_config i2s_config;
> +
> + switch (fmt & SND_SOC_DAIFMT_MASTER_MASK) {
> + case SND_SOC_DAIFMT_CBS_CFS:
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + switch (fmt & SND_SOC_DAIFMT_INV_MASK) {
> + case SND_SOC_DAIFMT_NB_NF:
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + switch (fmt & SND_SOC_DAIFMT_FORMAT_MASK) {
> + case SND_SOC_DAIFMT_I2S:
> + i2s_config = EC_DAI_FMT_I2S;
> + break;
> +
> + case SND_SOC_DAIFMT_RIGHT_J:
> + i2s_config = EC_DAI_FMT_RIGHT_J;
> + break;
> +
> + case SND_SOC_DAIFMT_LEFT_J:
> + i2s_config = EC_DAI_FMT_LEFT_J;
> + break;
> +
> + case SND_SOC_DAIFMT_DSP_A:
> + i2s_config = EC_DAI_FMT_PCM_A;
> + break;
> +
> + case SND_SOC_DAIFMT_DSP_B:
> + i2s_config = EC_DAI_FMT_PCM_B;
> + break;
> +
> + default:
> + return -EINVAL;
> + }
> +
> + set_i2s_config(component, i2s_config);
> +
> + return 0;
> +}
> +
> +static int set_i2s_sample_depth(struct snd_soc_component *component,
> + enum ec_sample_depth_value depth)
> +{
> + struct ec_param_codec_i2s param;
> + int ret;
> +
> + dev_dbg(component->dev, "%s set depth to %u\n", __func__, depth);
> +
> + param.cmd = EC_CODEC_SET_SAMPLE_DEPTH;
> + param.depth = depth;
> +
> + ret = ec_command(component, 0, EC_CMD_CODEC_I2S,
> + (u8 *)&param, sizeof(param),
> + NULL, 0);
> + if (ret < 0) {
> + dev_err(component->dev, "I2S sample depth %u returned %d\n",
> + depth, ret);

Is all that error noise common in ASoC drivers ? If it can result in
log spam, I would recommend against it.

> + return -EINVAL;

Same as above and everywhere else.

> + }
> + return 0;
> +}
> +
> +static int set_bclk(struct snd_soc_component *component, uint32_t bclk)
> +{
> + struct ec_param_codec_i2s param;
> + int ret;
> +
> + dev_dbg(component->dev, "%s set i2s bclk to %u\n", __func__, bclk);
> +
> + param.cmd = EC_CODEC_I2S_SET_BCLK;
> + param.bclk = bclk;
> +
> + ret = ec_command(component, 0, EC_CMD_CODEC_I2S,
> + (u8 *)&param, sizeof(param),
> + NULL, 0);
> + if (ret < 0) {
> + dev_err(component->dev, "I2S set bclk %u command returned %d\n",
> + bclk, ret);
> + return -EINVAL;
> + }
> + return 0;
> +}
> +
> +static int cros_ec_i2s_hw_params(struct snd_pcm_substream *substream,
> + struct snd_pcm_hw_params *params,
> + struct snd_soc_dai *dai)
> +{
> + struct snd_soc_component *component = dai->component;
> + int frame_size;
> + unsigned int rate, bclk;
> + int ret;
> +
> + frame_size = snd_soc_params_to_frame_size(params);
> + if (frame_size < 0) {
> + dev_err(component->dev, "Unsupported frame size: %d\n",
> + frame_size);
> + return -EINVAL;
> + }
> +
> + rate = params_rate(params);
> + if (rate != 48000) {
> + dev_err(component->dev, "Unsupported rate\n");
> + return -EINVAL;
> + }
> +
> + switch (params_format(params)) {
> + case SNDRV_PCM_FORMAT_S16_LE:
> + ret = set_i2s_sample_depth(component, EC_CODEC_SAMPLE_DEPTH_16);
> + break;
> + case SNDRV_PCM_FORMAT_S24_LE:
> + ret = set_i2s_sample_depth(component, EC_CODEC_SAMPLE_DEPTH_24);
> + break;
> + default:
> + return -EINVAL;
> + }
> +
> + if (ret)
> + return ret;
> +
> + bclk = snd_soc_params_to_bclk(params);
> + ret = set_bclk(component, bclk);
> +
> + return ret;
> +}
> +
> +static const struct snd_soc_dai_ops cros_ec_i2s_dai_ops = {
> + .hw_params = cros_ec_i2s_hw_params,
> + .set_fmt = cros_ec_i2s_set_dai_fmt,
> +};
> +
> +struct snd_soc_dai_driver cros_ec_dai[] = {
> + {
> + .name = "cros_ec_codec I2S",
> + .id = 0,
> + .capture = {
> + .stream_name = "I2S Capture",
> + .channels_min = 2,
> + .channels_max = 2,
> + .rates = SNDRV_PCM_RATE_48000,
> + .formats = SNDRV_PCM_FMTBIT_S16_LE |
> + SNDRV_PCM_FMTBIT_S24_LE,
> + },
> + .ops = &cros_ec_i2s_dai_ops,
> + }
> +};
> +
> +static int get_ec_mic_gain(struct snd_soc_component *component,
> + u8 *left, u8 *right)
> +{
> + struct ec_param_codec_i2s param;
> + struct ec_response_codec_gain resp;
> + int ret;
> +
> + param.cmd = EC_CODEC_GET_GAIN;
> +
> + ret = ec_command(component, 0, EC_CMD_CODEC_I2S,
> + (u8 *)&param, sizeof(param),
> + (u8 *)&resp, sizeof(resp));
> + if (ret < 0) {
> + dev_err(component->dev, "I2S get gain command returned %d\n",
> + ret);
> + return -EINVAL;
> + }
> +
> + *left = resp.left;
> + *right = resp.right;
> +
> + dev_dbg(component->dev, "%s get mic gain %u, %u\n", __func__,
> + *left, *right);
> +
> + return 0;
> +}
> +
> +static int mic_gain_get(struct snd_kcontrol *kcontrol,
> + struct snd_ctl_elem_value *ucontrol)
> +{
> + struct snd_soc_component *component =
> + snd_soc_kcontrol_component(kcontrol);
> + u8 left, right;
> + int ret;
> +
> + ret = get_ec_mic_gain(component, &left, &right);
> +
An empty line before checking return codes used to result in a
checkpatch warning. Even if that is not so anymore, I would suggest to
remove such empty lines as unnecessary.

> + if (ret)
> + return ret;
> +
> + ucontrol->value.integer.value[0] = left;
> + ucontrol->value.integer.value[1] = right;
> +
> + return 0;
> +}
> +
> +static int set_ec_mic_gain(struct snd_soc_component *component,
> + u8 left, u8 right)
> +{
> + struct ec_param_codec_i2s param;
> + int ret;
> +
> + dev_dbg(component->dev, "%s set mic gain to %u, %u\n",
> + __func__, left, right);
> +
> + param.cmd = EC_CODEC_SET_GAIN;
> + param.gain.left = left;
> + param.gain.right = right;
> +
> + ret = ec_command(component, 0, EC_CMD_CODEC_I2S,
> + (u8 *)&param, sizeof(param),
> + NULL, 0);
> + if (ret < 0) {
> + dev_err(component->dev, "I2S set gain command returned %d\n",
> + ret);
> + return -EINVAL;
> + }
> +
> + return 0;
> +}
> +
> +static int mic_gain_put(struct snd_kcontrol *kcontrol,
> + struct snd_ctl_elem_value *ucontrol)
> +{
> + struct snd_soc_component *component =
> + snd_soc_kcontrol_component(kcontrol);
> + int left = ucontrol->value.integer.value[0];
> + int right = ucontrol->value.integer.value[1];
> + int ret;
> +
> + if (left > MAX_GAIN || right > MAX_GAIN)
> + return -EINVAL;
> +
> + ret = set_ec_mic_gain(component, (u8)left, (u8)right);
> +
> + if (ret)
> + return ret;
> +
> + return 0;
> +}
> +
> +static const struct snd_kcontrol_new cros_ec_snd_controls[] = {
> + SOC_DOUBLE_EXT_TLV("EC Mic Gain", SND_SOC_NOPM, SND_SOC_NOPM, 0, 43, 0,
> + mic_gain_get, mic_gain_put, ec_mic_gain_tlv)
> +};
> +
> +static int enable_i2s(struct snd_soc_component *component, int enable)
> +{
> + struct ec_param_codec_i2s param;
> + int ret;
> +
> + dev_dbg(component->dev, "%s set i2s to %u\n", __func__, enable);
> +
> + param.cmd = EC_CODEC_I2S_ENABLE;
> + param.i2s_enable = enable;
> +
> + ret = ec_command(component, 0, EC_CMD_CODEC_I2S,
> + (u8 *)&param, sizeof(param),
> + NULL, 0);
> + if (ret < 0) {
> + dev_err(component->dev, "I2S enable %d command returned %d\n",
> + enable, ret);
> + return -EINVAL;
> + }
> + return 0;
> +}
> +
> +static int cros_ec_i2s_enable_event(struct snd_soc_dapm_widget *w,
> + struct snd_kcontrol *kcontrol, int event)
> +{
> + struct snd_soc_component *component =
> + snd_soc_dapm_to_component(w->dapm);
> +
> + switch (event) {
> + case SND_SOC_DAPM_PRE_PMU:
> + dev_dbg(component->dev,
> + "%s got SND_SOC_DAPM_PRE_PMU event\n", __func__);
> + return enable_i2s(component, 1);
> +
> + case SND_SOC_DAPM_PRE_PMD:
> + dev_dbg(component->dev,
> + "%s got SND_SOC_DAPM_PRE_PMD event\n", __func__);
> + return enable_i2s(component, 0);
> + }
> +
> + return 0;
> +}
> +
> +/*
> + * The goal of this DAPM route is to turn on/off I2S using EC
> + * host command when capture stream is started/stopped.
> + */
> +static const struct snd_soc_dapm_widget cros_ec_dapm_widgets[] = {
> + SND_SOC_DAPM_INPUT("DMIC"),
> +
> + /*
> + * Control EC to enable/disable I2S.
> + */
> + SND_SOC_DAPM_SUPPLY("I2S Enable", SND_SOC_NOPM,
> + 0, 0, cros_ec_i2s_enable_event,
> + SND_SOC_DAPM_PRE_PMU | SND_SOC_DAPM_PRE_PMD),
> +
> + SND_SOC_DAPM_AIF_OUT("I2STX", "I2S Capture", 0, SND_SOC_NOPM, 0, 0),
> +};
> +
> +static const struct snd_soc_dapm_route cros_ec_dapm_routes[] = {
> + { "I2STX", NULL, "DMIC" },
> + { "I2STX", NULL, "I2S Enable" },
> +};
> +
> +static const struct snd_soc_component_driver cros_ec_component_driver = {
> + .controls = cros_ec_snd_controls,
> + .num_controls = ARRAY_SIZE(cros_ec_snd_controls),
> + .dapm_widgets = cros_ec_dapm_widgets,
> + .num_dapm_widgets = ARRAY_SIZE(cros_ec_dapm_widgets),
> + .dapm_routes = cros_ec_dapm_routes,
> + .num_dapm_routes = ARRAY_SIZE(cros_ec_dapm_routes),
> +};
> +
> +/*
> + * Platform device and platform driver fro cros-ec-codec.
> + */
> +static int cros_ec_codec_platform_probe(struct platform_device *pd)
> +{
> + struct device *dev = &pd->dev;
> + struct cros_ec_device *ec_device = dev_get_drvdata(pd->dev.parent);
> + struct cros_ec_codec_data *codec_data;
> + int rc;
> +
> + codec_data = devm_kzalloc(dev, sizeof(struct cros_ec_codec_data),
> + GFP_KERNEL);
> + if (!codec_data)
> + return -ENOMEM;
> +
> + codec_data->dev = dev;
> + codec_data->ec_device = ec_device;
> +
> + platform_set_drvdata(pd, codec_data);
> +
> + rc = snd_soc_register_component(dev, &cros_ec_component_driver,
> + cros_ec_dai, ARRAY_SIZE(cros_ec_dai));
> +
> + dev_dbg(dev, "%s done\n", __func__);
> +
> + return 0;
> +}
> +
> +#ifdef CONFIG_OF
> +static const struct of_device_id cros_ec_codec_of_match[] = {
> + { .compatible = "google,cros-ec-codec" },
> + {},
> +};
> +MODULE_DEVICE_TABLE(of, cros_ec_codec_of_match);
> +#endif
> +
> +static struct platform_driver cros_ec_codec_platform_driver = {
> + .driver = {
> + .name = DRV_NAME,
> + .of_match_table = of_match_ptr(cros_ec_codec_of_match),
> + },
> + .probe = cros_ec_codec_platform_probe,
> +};
> +
> +module_platform_driver(cros_ec_codec_platform_driver);
> +
> +MODULE_LICENSE("GPL v2");
> +MODULE_DESCRIPTION("ChromeOS EC codec driver");
> +MODULE_AUTHOR("Cheng-Yi Chiang <cychiang@xxxxxxxxxxxx>");
> +MODULE_ALIAS("platform:" DRV_NAME);
> diff --git a/sound/soc/codecs/cros_ec_codec.h b/sound/soc/codecs/cros_ec_codec.h
> new file mode 100644
> index 0000000000000..3c566079f4ee2
> --- /dev/null
> +++ b/sound/soc/codecs/cros_ec_codec.h

I don't see the point of this include file. The data structure it
defines is only used in a single source file, and may as well be
defined there. I would suggest to do that unless it is common practice
in ASoC drivers.

> @@ -0,0 +1,21 @@
> +/* SPDX-License-Identifier: GPL-2.0 */
> +/*
> + * ChromeOS EC Codec
> + */
> +
> +#ifndef __CROS_EC_CODEC_H
> +#define __CROS_EC_CODEC_H
> +
> +/**
> + * struct cros_ec_codec_data - ChromeOS EC codec driver data.
> + * @dev: Device structure used in sysfs.
> + * @ec_device: cros_ec_device structure to talk to the physical device.
> + * @component: Pointer to the component.
> + */
> +struct cros_ec_codec_data {
> + struct device *dev;
> + struct cros_ec_device *ec_device;
> + struct snd_soc_component *component;
> +};
> +
> +#endif /* __CROS_EC_CODEC_H */
> --
> 2.20.1.415.g653613c723-goog
>