Re: [alsa-devel] [PATCH v3 3/3] ASoC: cros_ec_codec: Add codec driver for Cros EC

On Wed, Dec 26, 2018 at 03:03:19PM +0800, Cheng-Yi Chiang 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@chromium.org

Changes in v3: 1.remove cros_ec_codec.h. 2.Fix error code overriding in set_i2s_config set_i2s_sample_depth set_bclk get_ec_mic_gain set_ec_mic_gain enable_i2s 3.Fix missing return code in cros_ec_i2s_set_dai_fmt. 4.Simplify return code in cros_ec_i2s_hw_params and mic_gain_put. 5.Remove useless debug message in cros_ec_codec_platform_probe.

MAINTAINERS | 2 + sound/soc/codecs/Kconfig | 8 + sound/soc/codecs/Makefile | 2 + sound/soc/codecs/cros_ec_codec.c | 454 +++++++++++++++++++++++++++++++ 4 files changed, 466 insertions(+) create mode 100644 sound/soc/codecs/cros_ec_codec.c

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@chromium.org +R: Enric Balletbo i Serra enric.balletbo@collabora.com 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@cirrus.com 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

This unconditionally selects SND_SOC_CROS_EC_CODEC, but SND_SOC_CROS_EC_CODEC depends on MFD_CROS_EC. This is missing an "if MFD_CROS_EC" qualifier.

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..85ea23f4b681c --- /dev/null +++ b/sound/soc/codecs/cros_ec_codec.c @@ -0,0 +1,454 @@ +// 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>

+#define MAX_GAIN 43

Is there some reason for this magic number ? What does it reflect ?

+#define DRV_NAME "cros-ec-codec"

+/**

• • 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;

+};

+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;
  

As far as I can see, the calling parameter is always "struct ec_param_codec_i2s". With that in mind, this code seems unnecessarily complex. Is this code expected to be called multiple times in parallel and requires multiple instances of struct ec_param_codec_i2s to be allocated ? Even if so, why not just use a local variable / array ?

[ This makes me wonder how EC transfers are synchronized in cros_ec_cmd_xfer_status() and below. Does anyone know ? I don't immedately see it. ]

• 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;

I know this is wide-spread in cros_ec drivers, but that doesn't make it better. The positive return value isn't used anywhere. On top of that, the called low level code already generates error messages. As a result, the code calling this function is unnecessarily complex. If the function was to return 0 for success and a negative error code otherwise, pret much all all callers could be simplified to

return ec_command(...);

+}

+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 ret;
  

• }
• 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;
  

• }
• return set_i2s_config(component, i2s_config);

+}

+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);
  

• return ret;
  

• }
• 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 ret;
  

• }
• 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;
  

There is quite some inconsistency in error messages. Is there some kind of plan behind it ? Do the error mesages above add value, but an error message here wouldn't ?

• }
• if (ret < 0)

• return ret;
  

• bclk = snd_soc_params_to_bclk(params);
• return set_bclk(component, bclk);

+}

+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 ret;
  

• }
• *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);
• 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 ret;
  

• }
• 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];
• if (left > MAX_GAIN || right > MAX_GAIN)

• return -EINVAL;
  

• return set_ec_mic_gain(component, (u8)left, (u8)right);

+}

+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 ret;
  

• }
• 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));
  

• return 0;

Why ignore errors from snd_soc_register_component() ? Is this on purpose or an oversight ?

+}

+#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);

The "platform" in the various variable and function names don't really add any value.

+MODULE_LICENSE("GPL v2"); +MODULE_DESCRIPTION("ChromeOS EC codec driver"); +MODULE_AUTHOR("Cheng-Yi Chiang cychiang@chromium.org"); +MODULE_ALIAS("platform:" DRV_NAME);