[PATCH] leds: lm3532: Avoid potentially unpaired regulator calls

From: Tony Lindgren <tony@atomide.com>
To: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Cc: Pavel Machek <pavel@ucw.cz>, Dan Murphy <dmurphy@ti.com>,
	linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: [PATCH] leds: lm3532: Avoid potentially unpaired regulator calls
Date: Tue, 27 Aug 2019 14:52:05 -0700	[thread overview]
Message-ID: <20190827215205.59677-1-tony@atomide.com> (raw)

We may currently get unpaired regulator calls when configuring the LED
brightness via sysfs in case of regulator calls producing errors. Let's
fix this by maintaining local state for enabled.

Signed-off-by: Tony Lindgren <tony@atomide.com>
---
 drivers/leds/leds-lm3532.c | 26 ++++++++++++++++++++++++--
 1 file changed, 24 insertions(+), 2 deletions(-)

diff --git a/drivers/leds/leds-lm3532.c b/drivers/leds/leds-lm3532.c
--- a/drivers/leds/leds-lm3532.c
+++ b/drivers/leds/leds-lm3532.c
@@ -127,6 +127,7 @@ struct lm3532_als_data {
  * @num_leds - Number of LED strings are supported in this array
  * @full_scale_current - The full-scale current setting for the current sink.
  * @led_strings - The LED strings supported in this array
+ * @enabled - Enabled status
  * @label - LED label
  */
 struct lm3532_led {
@@ -138,6 +139,7 @@ struct lm3532_led {
 	int ctrl_brt_pointer;
 	int num_leds;
 	int full_scale_current;
+	int enabled:1;
 	u32 led_strings[LM3532_MAX_CONTROL_BANKS];
 	char label[LED_MAX_NAME_SIZE];
 };
@@ -292,11 +294,15 @@ static int lm3532_get_ramp_index(int ramp_time)
 				ramp_time);
 }
 
+/* Caller must take care of locking */
 static int lm3532_led_enable(struct lm3532_led *led_data)
 {
 	int ctrl_en_val = BIT(led_data->control_bank);
 	int ret;
 
+	if (led_data->enabled)
+		return 0;
+
 	ret = regmap_update_bits(led_data->priv->regmap, LM3532_REG_ENABLE,
 					 ctrl_en_val, ctrl_en_val);
 	if (ret) {
@@ -304,14 +310,24 @@ static int lm3532_led_enable(struct lm3532_led *led_data)
 		return ret;
 	}
 
-	return regulator_enable(led_data->priv->regulator);
+	ret = regulator_enable(led_data->priv->regulator);
+	if (ret < 0)
+		return ret;
+
+	led_data->enabled = 1;
+
+	return 0;
 }
 
+/* Caller must take care of locking */
 static int lm3532_led_disable(struct lm3532_led *led_data)
 {
 	int ctrl_en_val = BIT(led_data->control_bank);
 	int ret;
 
+	if (!led_data->enabled)
+		return 0;
+
 	ret = regmap_update_bits(led_data->priv->regmap, LM3532_REG_ENABLE,
 					 ctrl_en_val, 0);
 	if (ret) {
@@ -319,7 +335,13 @@ static int lm3532_led_disable(struct lm3532_led *led_data)
 		return ret;
 	}
 
-	return regulator_disable(led_data->priv->regulator);
+	ret = regulator_disable(led_data->priv->regulator);
+	if (ret < 0)
+		return ret;
+
+	led_data->enabled = 0;
+
+	return 0;
 }
 
 static int lm3532_brightness_set(struct led_classdev *led_cdev,
-- 
2.23.0
