linux-kernel - [PATCH v2 5/5] iio: sx9310: Enable vdd and svdd regulators at probe

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Date:   Fri, 24 Jul 2020 14:33:29 -0700
From:   Stephen Boyd <swboyd@...omium.org>
To:     Jonathan Cameron <jic23@...nel.org>
Cc:     linux-kernel@...r.kernel.org, linux-iio@...r.kernel.org,
        Gwendal Grignou <gwendal@...omium.org>,
        Daniel Campello <campello@...omium.org>,
        Hartmut Knaack <knaack.h@....de>,
        Lars-Peter Clausen <lars@...afoo.de>,
        Peter Meerwald-Stadler <pmeerw@...erw.net>,
        Douglas Anderson <dianders@...omium.org>
Subject: [PATCH v2 5/5] iio: sx9310: Enable vdd and svdd regulators at probe

Enable the main power supply (vdd) and digital IO power supply (svdd)
during probe so that the i2c communication and device works properly on
boards that aggressively power gate these supplies.

Cc: Gwendal Grignou <gwendal@...omium.org>
Cc: Daniel Campello <campello@...omium.org>
Cc: Hartmut Knaack <knaack.h@....de>
Cc: Lars-Peter Clausen <lars@...afoo.de>
Cc: Peter Meerwald-Stadler <pmeerw@...erw.net>
Cc: Douglas Anderson <dianders@...omium.org>
Signed-off-by: Stephen Boyd <swboyd@...omium.org>
---
 drivers/iio/proximity/sx9310.c | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/drivers/iio/proximity/sx9310.c b/drivers/iio/proximity/sx9310.c
index 1e1f6bba50f6..ad6ed100c7a6 100644
--- a/drivers/iio/proximity/sx9310.c
+++ b/drivers/iio/proximity/sx9310.c
@@ -19,6 +19,7 @@
 #include <linux/of.h>
 #include <linux/pm.h>
 #include <linux/regmap.h>
+#include <linux/regulator/consumer.h>
 #include <linux/slab.h>
 
 #include <linux/iio/buffer.h>
@@ -899,12 +900,21 @@ static int sx9310_set_indio_dev_name(struct device *dev,
 	return 0;
 }
 
+static void sx9310_regulator_disable(void *supplies)
+{
+	regulator_bulk_disable(2, supplies);
+}
+
 static int sx9310_probe(struct i2c_client *client,
 			const struct i2c_device_id *id)
 {
 	int ret;
 	struct iio_dev *indio_dev;
 	struct sx9310_data *data;
+	struct regulator_bulk_data supplies[] = {
+		{ .supply = "vdd" },
+		{ .supply = "svdd" },
+	};
 
 	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
 	if (indio_dev == NULL)
@@ -919,6 +929,23 @@ static int sx9310_probe(struct i2c_client *client,
 	if (IS_ERR(data->regmap))
 		return PTR_ERR(data->regmap);
 
+	ret = devm_regulator_bulk_get(&client->dev, ARRAY_SIZE(supplies), supplies);
+	if (ret)
+		return ret;
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(supplies), supplies);
+	if (ret)
+		return ret;
+	/* Must wait for Tpor time after initial power up */
+	usleep_range(1000, 1100);
+
+	/* Update sx9310_regulator_disable() size if this bug is hit */
+	BUILD_BUG_ON(ARRAY_SIZE(supplies) != 2);
+	ret = devm_add_action_or_reset(&client->dev, sx9310_regulator_disable,
+				       supplies);
+	if (ret)
+		return ret;
+
 	ret = regmap_read(data->regmap, SX9310_REG_WHOAMI, &data->whoami);
 	if (ret < 0) {
 		dev_err(&client->dev, "error in reading WHOAMI register: %d\n",
-- 
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