bcm27xx: import latest patches from the RPi foundation

bcm2708: boot tested on RPi B+ v1.2
bcm2709: boot tested on RPi 3B v1.2 and RPi 4B v1.1 4G
bcm2710: boot tested on RPi 3B v1.2
bcm2711: boot tested on RPi 4B v1.1 4G

Signed-off-by: Álvaro Fernández Rojas <noltari@gmail.com>

1 files changed, 88 insertions, 0 deletions

diff --git a/target/linux/bcm27xx/patches-5.4/950-0930-backlight-gpio-Explicitly-set-the-direction-of-the-G.patch b/target/linux/bcm27xx/patches-5.4/950-0930-backlight-gpio-Explicitly-set-the-direction-of-the-G.patch
new file mode 100644
index 0000000000..d016cdaa43
--- /dev/null
+++ b/target/linux/bcm27xx/patches-5.4/950-0930-backlight-gpio-Explicitly-set-the-direction-of-the-G.patch
@@ -0,0 +1,88 @@
+From aa455fdc2495cb05b65cc03cc472de43df632c5c Mon Sep 17 00:00:00 2001
+From: Bartosz Golaszewski <bgolaszewski@baylibre.com>
+Date: Tue, 22 Oct 2019 10:36:24 +0200
+Subject: [PATCH] backlight: gpio: Explicitly set the direction of
+ the GPIO
+
+commit 706dc68102bc7421a9e6573d149ab6d769d71cc7 upstream.
+
+The GPIO backlight driver currently requests the line 'as is', without
+acively setting its direction. This can lead to problems: if the line
+is in input mode by default, we won't be able to drive it later when
+updating the status and also reading its initial value doesn't make
+sense for backlight setting.
+
+Request the line 'as is' initially, so that we can read its value
+without affecting it but then change the direction to output explicitly
+when setting the initial brightness.
+
+Also: check the current direction and only read the value if it's output.
+
+Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
+Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
+Signed-off-by: Lee Jones <lee.jones@linaro.org>
+---
+ drivers/video/backlight/gpio_backlight.c | 23 ++++++++++++++++++-----
+ 1 file changed, 18 insertions(+), 5 deletions(-)
+
+--- a/drivers/video/backlight/gpio_backlight.c
++++ b/drivers/video/backlight/gpio_backlight.c
+@@ -26,9 +26,8 @@ struct gpio_backlight {
+ 	int def_value;
+ };
+ 
+-static int gpio_backlight_update_status(struct backlight_device *bl)
++static int gpio_backlight_get_next_brightness(struct backlight_device *bl)
+ {
+-	struct gpio_backlight *gbl = bl_get_data(bl);
+ 	int brightness = bl->props.brightness;
+ 
+ 	if (bl->props.power != FB_BLANK_UNBLANK ||
+@@ -36,6 +35,14 @@ static int gpio_backlight_update_status(
+ 	    bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
+ 		brightness = 0;
+ 
++	return brightness;
++}
++
++static int gpio_backlight_update_status(struct backlight_device *bl)
++{
++	struct gpio_backlight *gbl = bl_get_data(bl);
++	int brightness = gpio_backlight_get_next_brightness(bl);
++
+ 	gpiod_set_value_cansleep(gbl->gpiod, brightness);
+ 
+ 	return 0;
+@@ -86,7 +93,8 @@ static int gpio_backlight_initial_power_
+ 		return gbl->def_value ? FB_BLANK_UNBLANK : FB_BLANK_POWERDOWN;
+ 
+ 	/* if the enable GPIO is disabled, do not enable the backlight */
+-	if (gpiod_get_value_cansleep(gbl->gpiod) == 0)
++	if (gpiod_get_direction(gbl->gpiod) == 0 &&
++	    gpiod_get_value_cansleep(gbl->gpiod) == 0)
+ 		return FB_BLANK_POWERDOWN;
+ 
+ 	return FB_BLANK_UNBLANK;
+@@ -100,7 +108,7 @@ static int gpio_backlight_probe(struct p
+ 	struct backlight_properties props;
+ 	struct backlight_device *bl;
+ 	struct gpio_backlight *gbl;
+-	int ret;
++	int ret, init_brightness;
+ 
+ 	gbl = devm_kzalloc(&pdev->dev, sizeof(*gbl), GFP_KERNEL);
+ 	if (gbl == NULL)
+@@ -153,7 +161,12 @@ static int gpio_backlight_probe(struct p
+ 	bl->props.power = gpio_backlight_initial_power_state(gbl);
+ 	bl->props.brightness = 1;
+ 
+-	backlight_update_status(bl);
++	init_brightness = gpio_backlight_get_next_brightness(bl);
++	ret = gpiod_direction_output(gbl->gpiod, init_brightness);
++	if (ret) {
++		dev_err(&pdev->dev, "failed to set initial brightness\n");
++		return ret;
++	}
+ 
+ 	platform_set_drvdata(pdev, bl);
+ 	return 0;