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From:   Yu-Hsuan Hsu <yuhsuan@chromium.org>
To:     linux-kernel@vger.kernel.org
Cc:     Benson Leung <bleung@chromium.org>,
        Enric Balletbo i Serra <enric.balletbo@collabora.com>,
        Guenter Roeck <groeck@chromium.org>,
        Cheng-Yi Chiang <cychiang@chromium.org>,
        Liam Girdwood <lgirdwood@gmail.com>,
        Mark Brown <broonie@kernel.org>,
        Jaroslav Kysela <perex@perex.cz>,
        Takashi Iwai <tiwai@suse.com>,
        Tzung-Bi Shih <tzungbi@google.com>,
        Gwendal Grignou <gwendal@chromium.org>,
        Lee Jones <lee.jones@linaro.org>,
        Yu-Hsuan Hsu <yuhsuan@chromium.org>,
        Yicheng Li <yichengli@chromium.org>,
        alsa-devel@alsa-project.org
Subject: [PATCH] ASoC: cros_ec_codec: Reset I2S RX when probing
Date:   Wed,  8 Jul 2020 15:11:17 +0800
Message-Id: <20200708071117.3070707-1-yuhsuan@chromium.org>
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Sender: linux-kernel-owner@vger.kernel.org
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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@chromium.org>
---
 include/linux/platform_data/cros_ec_commands.h | 1 +
 sound/soc/codecs/cros_ec_codec.c               | 7 +++++++
 2 files changed, 8 insertions(+)

diff --git a/include/linux/platform_data/cros_ec_commands.h b/include/linux/platform_data/cros_ec_commands.h
index 69210881ebac8..11ce917ca924c 100644
--- a/include/linux/platform_data/cros_ec_commands.h
+++ b/include/linux/platform_data/cros_ec_commands.h
@@ -4598,6 +4598,7 @@ 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 8d45c628e988e..5495214e73e68 100644
--- a/sound/soc/codecs/cros_ec_codec.c
+++ b/sound/soc/codecs/cros_ec_codec.c
@@ -1034,6 +1034,13 @@ 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)
+		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,
-- 
2.27.0.383.g050319c2ae-goog