linux-kernel - [PATCH v5] ASoC: cros_ec_codec: Reset I2S RX when probing

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Message-Id: <20210113081745.2543882-1-yuhsuan@chromium.org>
Date:   Wed, 13 Jan 2021 16:17:45 +0800
From:   Yu-Hsuan Hsu <yuhsuan@...omium.org>
To:     linux-kernel@...r.kernel.org
Cc:     Benson Leung <bleung@...omium.org>,
        Enric Balletbo i Serra <enric.balletbo@...labora.com>,
        Guenter Roeck <groeck@...omium.org>,
        Cheng-Yi Chiang <cychiang@...omium.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>,
        Jaroslav Kysela <perex@...ex.cz>,
        Takashi Iwai <tiwai@...e.com>,
        Prashant Malani <pmalani@...omium.org>,
        Pi-Hsun Shih <pihsun@...omium.org>,
        Yu-Hsuan Hsu <yuhsuan@...omium.org>,
        "Gustavo A . R . Silva" <gustavoars@...nel.org>,
        alsa-devel@...a-project.org
Subject: [PATCH v5] ASoC: cros_ec_codec: Reset I2S RX when probing

It is not guaranteed that I2S RX is disabled when the kernel booting.
For example, if the kernel crashes while it is enabled, it will keep
enabled until the next time EC reboots. Reset I2S RX when probing to
fix this issue.

Signed-off-by: Yu-Hsuan Hsu <yuhsuan@...omium.org>
---
This patch checks the return value. If it is -ENOPROTOOPT
(EC_RES_INVALID_VERSION), it will ask clients to update EC firmware.

Previous patches

v1: https://patchwork.kernel.org/project/alsa-devel/patch/20200708071117.3070707-1-yuhsuan@chromium.org/

v2: https://patchwork.kernel.org/project/alsa-devel/patch/20200716170914.3623060-1-yuhsuan@chromium.org/

v3: https://patchwork.kernel.org/project/alsa-devel/patch/20210106050559.1459027-1-yuhsuan@chromium.org/

v4: https://patchwork.kernel.org/project/alsa-devel/patch/20210107085942.2891525-2-yuhsuan@chromium.org/

 include/linux/platform_data/cros_ec_commands.h |  1 +
 sound/soc/codecs/cros_ec_codec.c               | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/include/linux/platform_data/cros_ec_commands.h b/include/linux/platform_data/cros_ec_commands.h
index 86376779ab31..95889ada83a3 100644
--- a/include/linux/platform_data/cros_ec_commands.h
+++ b/include/linux/platform_data/cros_ec_commands.h
@@ -4600,6 +4600,7 @@ enum ec_codec_i2s_rx_subcmd {
 	EC_CODEC_I2S_RX_SET_SAMPLE_DEPTH = 0x2,
 	EC_CODEC_I2S_RX_SET_DAIFMT = 0x3,
 	EC_CODEC_I2S_RX_SET_BCLK = 0x4,
+	EC_CODEC_I2S_RX_RESET = 0x5,
 	EC_CODEC_I2S_RX_SUBCMD_COUNT,
 };
 
diff --git a/sound/soc/codecs/cros_ec_codec.c b/sound/soc/codecs/cros_ec_codec.c
index f33a2a9654e7..d35c57724b45 100644
--- a/sound/soc/codecs/cros_ec_codec.c
+++ b/sound/soc/codecs/cros_ec_codec.c
@@ -1011,6 +1011,17 @@ static int cros_ec_codec_platform_probe(struct platform_device *pdev)
 	}
 	priv->ec_capabilities = r.capabilities;
 
+	/* Reset EC codec i2s rx. */
+	p.cmd = EC_CODEC_I2S_RX_RESET;
+	ret = send_ec_host_command(priv->ec_device, EC_CMD_EC_CODEC_I2S_RX,
+				   (uint8_t *)&p, sizeof(p), NULL, 0);
+	if (ret == -ENOPROTOOPT) {
+		dev_info(dev,
+			 "Command not found. Please update the EC firmware.\n");
+	} else if (ret) {
+		dev_err(dev, "failed to EC_CODEC_I2S_RESET: %d\n", ret);
+	}
+
 	platform_set_drvdata(pdev, priv);
 
 	ret = devm_snd_soc_register_component(dev, &i2s_rx_component_driver,
-- 
2.30.0.284.gd98b1dd5eaa7-goog