Merge tag 'backlight-for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight

Pull backlight updates from Lee Jones:
  Fix-ups:
   - Take heed of GPIO default-on requests; gpio_backlight
   - Enable DT probing; tps65217_bl

  Bug Fixes:
   - Free resources in error path; pwm_bl
   - Fix uninitialised variable warning; adp8860_bl, adp8870_bl
   - Protect unconditional DT look-ups from non-DT platforms; pwm_bl
   - Fix backlight flicker; pwm_bl

* tag 'backlight-for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/backlight:
  backlight: pwm_bl: Free PWM requested by legacy API on error path
  backlight: adp8860: Fix another uninitialized variable use
  backlight: gpio-backlight: Use default-on on GPIO request
  backlight: pwm_bl: Fix broken PWM backlight for non-dt platforms
  backlight: tps65217_bl: Add MODULE_DEVICE_TABLE
  backlight: pwm_bl: Avoid backlight flicker when probed from DT
  backlight: adp88x0: Fix uninitialized variable use

5 files changed, 58 insertions, 17 deletions

diff --git a/drivers/video/backlight/adp8860_bl.c b/drivers/video/backlight/adp8860_bl.c
index 98ffe71e8af2..510e559c060e 100644
--- a/drivers/video/backlight/adp8860_bl.c
+++ b/drivers/video/backlight/adp8860_bl.c
@@ -566,11 +566,13 @@ static ssize_t adp8860_bl_ambient_light_level_show(struct device *dev,
 
         mutex_lock(&data->lock);
         error = adp8860_read(data->client, ADP8860_PH1LEVL, &reg_val);
-        ret_val = reg_val;
-        error |= adp8860_read(data->client, ADP8860_PH1LEVH, &reg_val);
+        if (!error) {
+                ret_val = reg_val;
+                error = adp8860_read(data->client, ADP8860_PH1LEVH, &reg_val);
+        }
         mutex_unlock(&data->lock);
 
-        if (error < 0)
+        if (error)
                 return error;
 
         /* Return 13-bit conversion value for the first light sensor */
@@ -621,10 +623,12 @@ static ssize_t adp8860_bl_ambient_light_zone_store(struct device *dev,
 
                 /* Set user supplied ambient light zone */
                 mutex_lock(&data->lock);
-                adp8860_read(data->client, ADP8860_CFGR, &reg_val);
-                reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT);
-                reg_val |= (val - 1) << CFGR_BLV_SHIFT;
-                adp8860_write(data->client, ADP8860_CFGR, reg_val);
+                ret = adp8860_read(data->client, ADP8860_CFGR, &reg_val);
+                if (!ret) {
+                        reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT);
+                        reg_val |= (val - 1) << CFGR_BLV_SHIFT;
+                        adp8860_write(data->client, ADP8860_CFGR, reg_val);
+                }
                 mutex_unlock(&data->lock);
         }
 
diff --git a/drivers/video/backlight/adp8870_bl.c b/drivers/video/backlight/adp8870_bl.c
index 9d738352d7d4..21acac90fd77 100644
--- a/drivers/video/backlight/adp8870_bl.c
+++ b/drivers/video/backlight/adp8870_bl.c
@@ -807,10 +807,12 @@ static ssize_t adp8870_bl_ambient_light_zone_store(struct device *dev,
 
                 /* Set user supplied ambient light zone */
                 mutex_lock(&data->lock);
-                adp8870_read(data->client, ADP8870_CFGR, &reg_val);
-                reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT);
-                reg_val |= (val - 1) << CFGR_BLV_SHIFT;
-                adp8870_write(data->client, ADP8870_CFGR, reg_val);
+                ret = adp8870_read(data->client, ADP8870_CFGR, &reg_val);
+                if (!ret) {
+                        reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT);
+                        reg_val |= (val - 1) << CFGR_BLV_SHIFT;
+                        adp8870_write(data->client, ADP8870_CFGR, reg_val);
+                }
                 mutex_unlock(&data->lock);
         }
 
diff --git a/drivers/video/backlight/gpio_backlight.c b/drivers/video/backlight/gpio_backlight.c
index 5fbbc2ebdf93..18134416b154 100644
--- a/drivers/video/backlight/gpio_backlight.c
+++ b/drivers/video/backlight/gpio_backlight.c
@@ -89,6 +89,7 @@ static int gpio_backlight_probe(struct platform_device *pdev)
         struct backlight_device *bl;
         struct gpio_backlight *gbl;
         struct device_node *np = pdev->dev.of_node;
+        unsigned long flags = GPIOF_DIR_OUT;
         int ret;
 
         if (!pdata && !np) {
@@ -114,9 +115,12 @@ static int gpio_backlight_probe(struct platform_device *pdev)
                 gbl->def_value = pdata->def_value;
         }
 
-        ret = devm_gpio_request_one(gbl->dev, gbl->gpio, GPIOF_DIR_OUT |
-                                    (gbl->active ? GPIOF_INIT_LOW
-                                                 : GPIOF_INIT_HIGH),
+        if (gbl->active)
+                flags |= gbl->def_value ? GPIOF_INIT_HIGH : GPIOF_INIT_LOW;
+        else
+                flags |= gbl->def_value ? GPIOF_INIT_LOW : GPIOF_INIT_HIGH;
+
+        ret = devm_gpio_request_one(gbl->dev, gbl->gpio, flags,
                                     pdata ? pdata->name : "backlight");
         if (ret < 0) {
                 dev_err(&pdev->dev, "unable to request GPIO\n");
diff --git a/drivers/video/backlight/pwm_bl.c b/drivers/video/backlight/pwm_bl.c
index ae3c6b6fd5db..64f9e1b8655f 100644
--- a/drivers/video/backlight/pwm_bl.c
+++ b/drivers/video/backlight/pwm_bl.c
@@ -198,7 +198,9 @@ static int pwm_backlight_probe(struct platform_device *pdev)
         struct platform_pwm_backlight_data defdata;
         struct backlight_properties props;
         struct backlight_device *bl;
+        struct device_node *node = pdev->dev.of_node;
         struct pwm_bl_data *pb;
+        int initial_blank = FB_BLANK_UNBLANK;
         int ret;
 
         if (!data) {
@@ -242,7 +244,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
         pb->enabled = false;
 
         pb->enable_gpio = devm_gpiod_get_optional(&pdev->dev, "enable",
-                                                  GPIOD_OUT_HIGH);
+                                                  GPIOD_ASIS);
         if (IS_ERR(pb->enable_gpio)) {
                 ret = PTR_ERR(pb->enable_gpio);
                 goto err_alloc;
@@ -264,15 +266,32 @@ static int pwm_backlight_probe(struct platform_device *pdev)
                 pb->enable_gpio = gpio_to_desc(data->enable_gpio);
         }
 
+        if (pb->enable_gpio) {
+                /*
+                 * If the driver is probed from the device tree and there is a
+                 * phandle link pointing to the backlight node, it is safe to
+                 * assume that another driver will enable the backlight at the
+                 * appropriate time. Therefore, if it is disabled, keep it so.
+                 */
+                if (node && node->phandle &&
+                    gpiod_get_direction(pb->enable_gpio) == GPIOF_DIR_OUT &&
+                    gpiod_get_value(pb->enable_gpio) == 0)
+                        initial_blank = FB_BLANK_POWERDOWN;
+                else
+                        gpiod_direction_output(pb->enable_gpio, 1);
+        }
+
         pb->power_supply = devm_regulator_get(&pdev->dev, "power");
         if (IS_ERR(pb->power_supply)) {
                 ret = PTR_ERR(pb->power_supply);
                 goto err_alloc;
         }
 
+        if (node && node->phandle && !regulator_is_enabled(pb->power_supply))
+                initial_blank = FB_BLANK_POWERDOWN;
+
         pb->pwm = devm_pwm_get(&pdev->dev, NULL);
-        if (IS_ERR(pb->pwm) && PTR_ERR(pb->pwm) != -EPROBE_DEFER
-            && !pdev->dev.of_node) {
+        if (IS_ERR(pb->pwm) && PTR_ERR(pb->pwm) != -EPROBE_DEFER && !node) {
                 dev_err(&pdev->dev, "unable to request PWM, trying legacy API\n");
                 pb->legacy = true;
                 pb->pwm = pwm_request(data->pwm_id, "pwm-backlight");
@@ -309,6 +328,8 @@ static int pwm_backlight_probe(struct platform_device *pdev)
         if (IS_ERR(bl)) {
                 dev_err(&pdev->dev, "failed to register backlight\n");
                 ret = PTR_ERR(bl);
+                if (pb->legacy)
+                        pwm_free(pb->pwm);
                 goto err_alloc;
         }
 
@@ -320,6 +341,7 @@ static int pwm_backlight_probe(struct platform_device *pdev)
         }
 
         bl->props.brightness = data->dft_brightness;
+        bl->props.power = initial_blank;
         backlight_update_status(bl);
 
         platform_set_drvdata(pdev, bl);
diff --git a/drivers/video/backlight/tps65217_bl.c b/drivers/video/backlight/tps65217_bl.c
index 61d72bffd402..fd524ad860a5 100644
--- a/drivers/video/backlight/tps65217_bl.c
+++ b/drivers/video/backlight/tps65217_bl.c
@@ -320,10 +320,19 @@ static int tps65217_bl_probe(struct platform_device *pdev)
         return 0;
 }
 
+#ifdef CONFIG_OF
+static const struct of_device_id tps65217_bl_of_match[] = {
+        { .compatible = "ti,tps65217-bl", },
+        { /* sentinel */ },
+};
+MODULE_DEVICE_TABLE(of, tps65217_bl_of_match);
+#endif
+
 static struct platform_driver tps65217_bl_driver = {
         .probe          = tps65217_bl_probe,
         .driver         = {
                 .name   = "tps65217-bl",
+                .of_match_table = of_match_ptr(tps65217_bl_of_match),
         },
 };