linux-kernel - [PATCH 2/6] ASoC: codecs: wcd938x: Keep device in reset till bind

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Date:   Thu, 20 Apr 2023 12:16:13 +0200
From:   Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>
To:     Vinod Koul <vkoul@...nel.org>,
        Bard Liao <yung-chuan.liao@...ux.intel.com>,
        Pierre-Louis Bossart <pierre-louis.bossart@...ux.intel.com>,
        Sanyog Kale <sanyog.r.kale@...el.com>,
        Andy Gross <agross@...nel.org>,
        Bjorn Andersson <andersson@...nel.org>,
        Konrad Dybcio <konrad.dybcio@...aro.org>,
        Liam Girdwood <lgirdwood@...il.com>,
        Mark Brown <broonie@...nel.org>,
        Jaroslav Kysela <perex@...ex.cz>,
        Takashi Iwai <tiwai@...e.com>, alsa-devel@...a-project.org,
        linux-kernel@...r.kernel.org, linux-arm-msm@...r.kernel.org
Cc:     Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>,
        Patrick Lai <quic_plai@...cinc.com>
Subject: [PATCH 2/6] ASoC: codecs: wcd938x: Keep device in reset till bind

The Soundwire master expects that bus devices will be kept in reset
state and brought out of it in their Soundwire probe() or bind().
Keeping it in reset state avoids early new Soundwire device interrupts
in the master.  Fix this in WCD938x platform driver by moving the reset
toggle code from platform probe() to component bind().

Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@...aro.org>

---

I wasn't sure whether this deserves a Fixes tag. It looks like a fix,
but OTOH, I don't think Soundwire master expectation is documented
anywhere.

Cc: Patrick Lai <quic_plai@...cinc.com>
---
 sound/soc/codecs/wcd938x.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/sound/soc/codecs/wcd938x.c b/sound/soc/codecs/wcd938x.c
index 33fd8fdde9fd..212667a7249c 100644
--- a/sound/soc/codecs/wcd938x.c
+++ b/sound/soc/codecs/wcd938x.c
@@ -4236,7 +4236,8 @@ static int wcd938x_populate_dt_data(struct wcd938x_priv *wcd938x, struct device
 	struct wcd_mbhc_config *cfg = &wcd938x->mbhc_cfg;
 	int ret;
 
-	wcd938x->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_ASIS);
+	/* Keep device in reset status till wcd938x_bind() */
+	wcd938x->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
 	ret = PTR_ERR_OR_ZERO(wcd938x->reset_gpio);
 	if (ret)
 		return dev_err_probe(dev, ret, "Failed to get reset gpio\n");
@@ -4407,6 +4408,8 @@ static int wcd938x_bind(struct device *dev)
 		return -EINVAL;
 	}
 
+	wcd938x_reset(wcd938x);
+
 	wcd938x->regmap = devm_regmap_init_sdw(wcd938x->tx_sdw_dev, &wcd938x_regmap_config);
 	if (IS_ERR(wcd938x->regmap)) {
 		dev_err(dev, "%s: tx csr regmap not found\n", __func__);
@@ -4508,8 +4511,6 @@ static int wcd938x_probe(struct platform_device *pdev)
 	if (ret)
 		return ret;
 
-	wcd938x_reset(wcd938x);
-
 	ret = component_master_add_with_match(dev, &wcd938x_comp_ops, match);
 	if (ret)
 		return ret;
-- 
2.34.1