linux-kernel - [PATCH v3 12/12] regulator: pwm: properly initialize the ->state field

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Date:	Mon, 21 Sep 2015 11:33:29 +0200
From:	Boris Brezillon <boris.brezillon@...e-electrons.com>
To:	Thierry Reding <thierry.reding@...il.com>,
	linux-pwm@...r.kernel.org, Mark Brown <broonie@...nel.org>,
	Liam Girdwood <lgirdwood@...il.com>,
	Jingoo Han <jingoohan1@...il.com>,
	Lee Jones <lee.jones@...aro.org>, linux-fbdev@...r.kernel.org,
	Bryan Wu <cooloney@...il.com>,
	Richard Purdie <rpurdie@...ys.net>,
	Jacek Anaszewski <j.anaszewski@...sung.com>,
	linux-leds@...r.kernel.org,
	Maxime Ripard <maxime.ripard@...e-electrons.com>,
	linux-sunxi@...glegroups.com, Heiko Stuebner <heiko@...ech.de>,
	linux-rockchip@...ts.infradead.org,
	Jean-Christophe Plagniol-Villard <plagnioj@...osoft.com>,
	Tomi Valkeinen <tomi.valkeinen@...com>,
	Daniel Mack <daniel@...que.org>,
	Haojian Zhuang <haojian.zhuang@...il.com>,
	Robert Jarzmik <robert.jarzmik@...e.fr>
Cc:	linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
	Doug Anderson <dianders@...gle.com>,
	Uwe Kleine-König 
	<u.kleine-koenig@...gutronix.de>,
	Boris Brezillon <boris.brezillon@...e-electrons.com>
Subject: [PATCH v3 12/12] regulator: pwm: properly initialize the ->state field

The ->state field is currently initialized to 0, thus referencing the
voltage selector at index 0, which might not reflect the current voltage
value.
If possible, retrieve the current voltage selector from the PWM state, else
return -EINVAL.

Signed-off-by: Boris Brezillon <boris.brezillon@...e-electrons.com>
---
 drivers/regulator/pwm-regulator.c | 26 ++++++++++++++++++++++++++
 1 file changed, 26 insertions(+)

diff --git a/drivers/regulator/pwm-regulator.c b/drivers/regulator/pwm-regulator.c
index 9ffdbd6..449e3b3 100644
--- a/drivers/regulator/pwm-regulator.c
+++ b/drivers/regulator/pwm-regulator.c
@@ -41,10 +41,35 @@ struct pwm_voltages {
 /**
  * Voltage table call-backs
  */
+static void pwm_regulator_init_state(struct regulator_dev *rdev)
+{
+	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
+	struct pwm_state pwm_state;
+	unsigned int dutycycle;
+	int i;
+
+	pwm_get_state(drvdata->pwm, &pwm_state);
+
+	if (!pwm_state.period)
+		return;
+
+	dutycycle = (pwm_state.duty_cycle * 100) / pwm_state.period;
+
+	for (i = 0; i < rdev->desc->n_voltages; i++) {
+		if (dutycycle == drvdata->duty_cycle_table[i].dutycycle) {
+			drvdata->state = i;
+			return;
+		}
+	}
+}
+
 static int pwm_regulator_get_voltage_sel(struct regulator_dev *rdev)
 {
 	struct pwm_regulator_data *drvdata = rdev_get_drvdata(rdev);
 
+	if (drvdata->state < 0)
+		pwm_regulator_init_state(rdev);
+
 	return drvdata->state;
 }
 
@@ -211,6 +236,7 @@ static int pwm_regulator_init_table(struct platform_device *pdev,
 		return ret;
 	}
 
+	drvdata->state			= -EINVAL;
 	drvdata->duty_cycle_table	= duty_cycle_table;
 	pwm_regulator_desc.ops		= &pwm_regulator_voltage_table_ops;
 	pwm_regulator_desc.n_voltages	= length / sizeof(*duty_cycle_table);
-- 
1.9.1

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