linux-kernel - [PATCH 2/2] Input: cyttsp5

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Message-ID: <20221117190507.87535-3-linmengbo0689@protonmail.com>
Date:   Thu, 17 Nov 2022 19:05:41 +0000
From:   "Lin, Meng-Bo" <linmengbo0689@...tonmail.com>
To:     linux-input@...r.kernel.org
Cc:     Dmitry Torokhov <dmitry.torokhov@...il.com>,
        Rob Herring <robh+dt@...nel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@...aro.org>,
        Linus Walleij <linus.walleij@...aro.org>,
        Alistair Francis <alistair@...stair23.me>,
        devicetree@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH 2/2] Input: cyttsp5 - add vddio regulator

The Samsung touchscreen controllers are often used with external pull-up
for the interrupt line and the I2C lines, so we might need to enable
a regulator to bring the lines into usable state. Otherwise, this might
cause spurious interrupts and reading from I2C will fail.

Implement support for a "vddio-supply" that is enabled by the cyttsp5
driver so that the regulator gets enabled when needed.

Signed-off-by: Lin, Meng-Bo <linmengbo0689@...tonmail.com>
---
 drivers/input/touchscreen/cyttsp5.c | 19 ++++++++++++-------
 1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/drivers/input/touchscreen/cyttsp5.c b/drivers/input/touchscreen/cyttsp5.c
index 24ab1df9fc07..d02fdb940edf 100644
--- a/drivers/input/touchscreen/cyttsp5.c
+++ b/drivers/input/touchscreen/cyttsp5.c
@@ -190,7 +190,7 @@ struct cyttsp5 {
 	int num_prv_rec;
 	struct regmap *regmap;
 	struct touchscreen_properties prop;
-	struct regulator *vdd;
+	struct regulator_bulk_data supplies[2];
 };
 
 /*
@@ -767,7 +767,7 @@ static void cyttsp5_cleanup(void *data)
 {
 	struct cyttsp5 *ts = data;
 
-	regulator_disable(ts->vdd);
+	regulator_bulk_disable(ARRAY_SIZE(ts->supplies), ts->supplies);
 }
 
 static int cyttsp5_probe(struct device *dev, struct regmap *regmap, int irq,
@@ -790,9 +790,12 @@ static int cyttsp5_probe(struct device *dev, struct regmap *regmap, int irq,
 	init_completion(&ts->cmd_done);
 
 	/* Power up the device */
-	ts->vdd = devm_regulator_get(dev, "vdd");
-	if (IS_ERR(ts->vdd)) {
-		error = PTR_ERR(ts->vdd);
+	ts->supplies[0].supply = "vdd";
+	ts->supplies[1].supply = "vddio";
+	error = devm_regulator_bulk_get(dev, ARRAY_SIZE(ts->supplies),
+				      ts->supplies);
+	if (error < 0) {
+		dev_err(ts->dev, "Failed to get regulators, error %d\n", error);
 		return error;
 	}
 
@@ -800,9 +803,11 @@ static int cyttsp5_probe(struct device *dev, struct regmap *regmap, int irq,
 	if (error)
 		return error;
 
-	error = regulator_enable(ts->vdd);
-	if (error)
+	error = regulator_bulk_enable(ARRAY_SIZE(ts->supplies), ts->supplies);
+	if (error < 0) {
+		dev_err(ts->dev, "Failed to enable regulators, error %d\n", error);
 		return error;
+	}
 
 	ts->input = devm_input_allocate_device(dev);
 	if (!ts->input) {
-- 
2.30.2