From: Tomi Valkeinen tomi.valkeinen@ti.com
This patch adds a led-backlight driver (led_bl), which is similar to pwm_bl except the driver uses a LED class driver to adjust the brightness in the HW. Multiple LEDs can be used for a single backlight.
Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com Acked-by: Pavel Machek pavel@ucw.cz Reviewed-by: Daniel Thompson daniel.thompson@linaro.org Acked-by: Lee Jones lee.jones@linaro.org Acked-by: Tony Lindgren tony@atomide.com Tested-by: Tony Lindgren tony@atomide.com Signed-off-by: Pavel Machek pavel@ucw.cz --- drivers/video/backlight/Kconfig | 7 ++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 268 insertions(+) create mode 100644 drivers/video/backlight/led_bl.c
Hi!
Here's the version of the driver I have. AFAICT default-brightness-level handling is ok, so does not need to be changed.
Lee, it would be easiest for me if you could apply it to your tree and push, but given enough time I can push it to Linus, too.
Thanks, Pavel
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index 403707a3e503..0093bbd0d326 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -456,6 +456,13 @@ config BACKLIGHT_RAVE_SP help Support for backlight control on RAVE SP device.
+config BACKLIGHT_LED + tristate "Generic LED based Backlight Driver" + depends on LEDS_CLASS && OF + help + If you have a LCD backlight adjustable by LED class driver, say Y + to enable this driver. + endif # BACKLIGHT_CLASS_DEVICE
endmenu diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index 6f8777037c37..0c1a1524627a 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -57,3 +57,4 @@ obj-$(CONFIG_BACKLIGHT_TPS65217) += tps65217_bl.o obj-$(CONFIG_BACKLIGHT_WM831X) += wm831x_bl.o obj-$(CONFIG_BACKLIGHT_ARCXCNN) += arcxcnn_bl.o obj-$(CONFIG_BACKLIGHT_RAVE_SP) += rave-sp-backlight.o +obj-$(CONFIG_BACKLIGHT_LED) += led_bl.o diff --git a/drivers/video/backlight/led_bl.c b/drivers/video/backlight/led_bl.c new file mode 100644 index 000000000000..3f66549997c8 --- /dev/null +++ b/drivers/video/backlight/led_bl.c @@ -0,0 +1,260 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Copyright (C) 2015-2019 Texas Instruments Incorporated - http://www.ti.com/ + * Author: Tomi Valkeinen tomi.valkeinen@ti.com + * + * Based on pwm_bl.c + */ + +#include <linux/backlight.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/platform_device.h> + +struct led_bl_data { + struct device *dev; + struct backlight_device *bl_dev; + struct led_classdev **leds; + bool enabled; + int nb_leds; + unsigned int *levels; + unsigned int default_brightness; + unsigned int max_brightness; +}; + +static void led_bl_set_brightness(struct led_bl_data *priv, int level) +{ + int i; + int bkl_brightness; + + if (priv->levels) + bkl_brightness = priv->levels[level]; + else + bkl_brightness = level; + + for (i = 0; i < priv->nb_leds; i++) + led_set_brightness(priv->leds[i], bkl_brightness); + + priv->enabled = true; +} + +static void led_bl_power_off(struct led_bl_data *priv) +{ + int i; + + if (!priv->enabled) + return; + + for (i = 0; i < priv->nb_leds; i++) + led_set_brightness(priv->leds[i], LED_OFF); + + priv->enabled = false; +} + +static int led_bl_update_status(struct backlight_device *bl) +{ + struct led_bl_data *priv = bl_get_data(bl); + int brightness = bl->props.brightness; + + if (bl->props.power != FB_BLANK_UNBLANK || + bl->props.fb_blank != FB_BLANK_UNBLANK || + bl->props.state & BL_CORE_FBBLANK) + brightness = 0; + + if (brightness > 0) + led_bl_set_brightness(priv, brightness); + else + led_bl_power_off(priv); + + return 0; +} + +static const struct backlight_ops led_bl_ops = { + .update_status = led_bl_update_status, +}; + +static int led_bl_get_leds(struct device *dev, + struct led_bl_data *priv) +{ + int i, nb_leds, ret; + struct device_node *node = dev->of_node; + struct led_classdev **leds; + unsigned int max_brightness; + unsigned int default_brightness; + + ret = of_count_phandle_with_args(node, "leds", NULL); + if (ret < 0) { + dev_err(dev, "Unable to get led count\n"); + return -EINVAL; + } + + nb_leds = ret; + if (nb_leds < 1) { + dev_err(dev, "At least one LED must be specified!\n"); + return -EINVAL; + } + + leds = devm_kzalloc(dev, sizeof(struct led_classdev *) * nb_leds, + GFP_KERNEL); + if (!leds) + return -ENOMEM; + + for (i = 0; i < nb_leds; i++) { + leds[i] = devm_of_led_get(dev, i); + if (IS_ERR(leds[i])) + return PTR_ERR(leds[i]); + } + + /* check that the LEDs all have the same brightness range */ + max_brightness = leds[0]->max_brightness; + for (i = 1; i < nb_leds; i++) { + if (max_brightness != leds[i]->max_brightness) { + dev_err(dev, "LEDs must have identical ranges\n"); + return -EINVAL; + } + } + + /* get the default brightness from the first LED from the list */ + default_brightness = leds[0]->brightness; + + priv->nb_leds = nb_leds; + priv->leds = leds; + priv->max_brightness = max_brightness; + priv->default_brightness = default_brightness; + + return 0; +} + +static int led_bl_parse_levels(struct device *dev, + struct led_bl_data *priv) +{ + struct device_node *node = dev->of_node; + int num_levels; + u32 value; + int ret; + + if (!node) + return -ENODEV; + + num_levels = of_property_count_u32_elems(node, "brightness-levels"); + if (num_levels > 1) { + int i; + unsigned int db; + u32 *levels = NULL; + + levels = devm_kzalloc(dev, sizeof(u32) * num_levels, + GFP_KERNEL); + if (!levels) + return -ENOMEM; + + ret = of_property_read_u32_array(node, "brightness-levels", + levels, + num_levels); + if (ret < 0) + return ret; + + /* + * Try to map actual LED brightness to backlight brightness + * level + */ + db = priv->default_brightness; + for (i = 0 ; i < num_levels; i++) { + if ((i && db > levels[i-1]) && db <= levels[i]) + break; + } + priv->default_brightness = i; + priv->max_brightness = num_levels - 1; + priv->levels = levels; + } else if (num_levels >= 0) + dev_warn(dev, "Not enough levels defined\n"); + + ret = of_property_read_u32(node, "default-brightness-level", &value); + if (!ret && value <= priv->max_brightness) + priv->default_brightness = value; + else if (!ret && value > priv->max_brightness) + dev_warn(dev, "Invalid default brightness. Ignoring it\n"); + + return 0; +} + +static int led_bl_probe(struct platform_device *pdev) +{ + struct backlight_properties props; + struct led_bl_data *priv; + int ret, i; + + priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + platform_set_drvdata(pdev, priv); + + priv->dev = &pdev->dev; + + ret = led_bl_get_leds(&pdev->dev, priv); + if (ret) + return ret; + + ret = led_bl_parse_levels(&pdev->dev, priv); + if (ret < 0) { + dev_err(&pdev->dev, "Failed to parse DT data\n"); + return ret; + } + + memset(&props, 0, sizeof(struct backlight_properties)); + props.type = BACKLIGHT_RAW; + props.max_brightness = priv->max_brightness; + props.brightness = priv->default_brightness; + props.power = (priv->default_brightness > 0) ? FB_BLANK_POWERDOWN : + FB_BLANK_UNBLANK; + priv->bl_dev = backlight_device_register(dev_name(&pdev->dev), + &pdev->dev, priv, &led_bl_ops, &props); + if (IS_ERR(priv->bl_dev)) { + dev_err(&pdev->dev, "Failed to register backlight\n"); + return PTR_ERR(priv->bl_dev); + } + + for (i = 0; i < priv->nb_leds; i++) + led_sysfs_disable(priv->leds[i]); + + backlight_update_status(priv->bl_dev); + + return 0; +} + +static int led_bl_remove(struct platform_device *pdev) +{ + struct led_bl_data *priv = platform_get_drvdata(pdev); + struct backlight_device *bl = priv->bl_dev; + int i; + + backlight_device_unregister(bl); + + led_bl_power_off(priv); + for (i = 0; i < priv->nb_leds; i++) + led_sysfs_enable(priv->leds[i]); + + return 0; +} + +static const struct of_device_id led_bl_of_match[] = { + { .compatible = "led-backlight" }, + { } +}; + +MODULE_DEVICE_TABLE(of, led_bl_of_match); + +static struct platform_driver led_bl_driver = { + .driver = { + .name = "led-backlight", + .of_match_table = of_match_ptr(led_bl_of_match), + }, + .probe = led_bl_probe, + .remove = led_bl_remove, +}; + +module_platform_driver(led_bl_driver); + +MODULE_DESCRIPTION("LED based Backlight Driver"); +MODULE_LICENSE("GPL"); +MODULE_ALIAS("platform:led-backlight");
* Pavel Machek pavel@ucw.cz [200219 19:15]:
From: Tomi Valkeinen tomi.valkeinen@ti.com
This patch adds a led-backlight driver (led_bl), which is similar to pwm_bl except the driver uses a LED class driver to adjust the brightness in the HW. Multiple LEDs can be used for a single backlight.
Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com Acked-by: Pavel Machek pavel@ucw.cz Reviewed-by: Daniel Thompson daniel.thompson@linaro.org Acked-by: Lee Jones lee.jones@linaro.org Acked-by: Tony Lindgren tony@atomide.com Tested-by: Tony Lindgren tony@atomide.com Signed-off-by: Pavel Machek pavel@ucw.cz
drivers/video/backlight/Kconfig | 7 ++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 268 insertions(+) create mode 100644 drivers/video/backlight/led_bl.c
Hi!
Here's the version of the driver I have. AFAICT default-brightness-level handling is ok, so does not need to be changed.
Lee, it would be easiest for me if you could apply it to your tree and push, but given enough time I can push it to Linus, too.
Oh you're using quoted-printable for patches.. Got it applied now, and it still works. Below is also the related dts change that I tested with.
Feel free to pick the dts change too, naturally that should not be applied before the driver.
If you guys instead want me to pick these both into my fixes branch, just let me know and I'll do the explaining why these are needed as fixes. Basically we no longer have a way to enable the LCD backlight for droid4 manually starting with v5.6-rc1 unlike earlier.
Regards,
Tony
8< ------------------
From tony Mon Sep 17 00:00:00 2001
From: Tony Lindgren tony@atomide.com Date: Wed, 19 Feb 2020 11:25:27 -0800 Subject: [PATCH] ARM: dts: droid4: Configure LED backlight for lm3532
With the LED backlight changes merged, we still need the dts configured to have backlight working for droid4. Based on an earlier patch from Pavel Machek pavel@ucw.cz, let's configure the backlight but update the value range to be more usable.
We have a range of 256 register values split into 8 steps, so we can generate the brightness levels backwards with:
$ for i in 0 1 2 3 4 5 6 7; do echo "255 - ${i} * (256 / 8)" | bc; done
To avoid more confusion why the LCD backlight is still not on, let's also enable LED backlight as a loadable module for omap2plus_defconfig.
Cc: Merlijn Wajer merlijn@wizzup.org Cc: Pavel Machek pavel@ucw.cz Signed-off-by: Tony Lindgren tony@atomide.com --- arch/arm/boot/dts/motorola-mapphone-common.dtsi | 13 +++++++++++-- arch/arm/configs/omap2plus_defconfig | 1 + 2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/arm/boot/dts/motorola-mapphone-common.dtsi b/arch/arm/boot/dts/motorola-mapphone-common.dtsi --- a/arch/arm/boot/dts/motorola-mapphone-common.dtsi +++ b/arch/arm/boot/dts/motorola-mapphone-common.dtsi @@ -182,6 +182,14 @@ vibrator { pwm-names = "enable", "direction"; direction-duty-cycle-ns = <10000000>; }; + + backlight: backlight { + compatible = "led-backlight"; + + leds = <&backlight_led>; + brightness-levels = <31 63 95 127 159 191 223 255>; + default-brightness-level = <6>; + }; };
&dss { @@ -205,6 +213,8 @@ lcd0: display { vddi-supply = <&lcd_regulator>; reset-gpios = <&gpio4 5 GPIO_ACTIVE_HIGH>; /* gpio101 */
+ backlight = <&backlight>; + width-mm = <50>; height-mm = <89>;
@@ -393,12 +403,11 @@ led-controller@38 { ramp-up-us = <1024>; ramp-down-us = <8193>;
- led@0 { + backlight_led: led@0 { reg = <0>; led-sources = <2>; ti,led-mode = <0>; label = ":backlight"; - linux,default-trigger = "backlight"; };
led@1 { diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig --- a/arch/arm/configs/omap2plus_defconfig +++ b/arch/arm/configs/omap2plus_defconfig @@ -375,6 +375,7 @@ CONFIG_BACKLIGHT_GENERIC=m CONFIG_BACKLIGHT_PWM=m CONFIG_BACKLIGHT_PANDORA=m CONFIG_BACKLIGHT_GPIO=m +CONFIG_BACKLIGHT_LED=m CONFIG_FRAMEBUFFER_CONSOLE=y CONFIG_FRAMEBUFFER_CONSOLE_ROTATION=y CONFIG_LOGO=y
Hi!
This patch adds a led-backlight driver (led_bl), which is similar to pwm_bl except the driver uses a LED class driver to adjust the brightness in the HW. Multiple LEDs can be used for a single backlight.
Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com Acked-by: Pavel Machek pavel@ucw.cz Reviewed-by: Daniel Thompson daniel.thompson@linaro.org Acked-by: Lee Jones lee.jones@linaro.org Acked-by: Tony Lindgren tony@atomide.com Tested-by: Tony Lindgren tony@atomide.com Signed-off-by: Pavel Machek pavel@ucw.cz
drivers/video/backlight/Kconfig | 7 ++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 268 insertions(+) create mode 100644 drivers/video/backlight/led_bl.c
Here's the version of the driver I have. AFAICT default-brightness-level handling is ok, so does not need to be changed.
Lee, it would be easiest for me if you could apply it to your tree and push, but given enough time I can push it to Linus, too.
Oh you're using quoted-printable for patches.. Got it applied now, and it still works. Below is also the related dts change that I tested with.
Feel free to pick the dts change too, naturally that should not be applied before the driver.
If you guys instead want me to pick these both into my fixes branch, just let me know and I'll do the explaining why these are needed as fixes. Basically we no longer have a way to enable the LCD backlight for droid4 manually starting with v5.6-rc1 unlike earlier.
If you are willing to do that, it looks like good solution from my point of view.
Thanks, Pavel
* Pavel Machek pavel@ucw.cz [200219 20:54]:
Hi!
This patch adds a led-backlight driver (led_bl), which is similar to pwm_bl except the driver uses a LED class driver to adjust the brightness in the HW. Multiple LEDs can be used for a single backlight.
Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com Acked-by: Pavel Machek pavel@ucw.cz Reviewed-by: Daniel Thompson daniel.thompson@linaro.org Acked-by: Lee Jones lee.jones@linaro.org Acked-by: Tony Lindgren tony@atomide.com Tested-by: Tony Lindgren tony@atomide.com Signed-off-by: Pavel Machek pavel@ucw.cz
drivers/video/backlight/Kconfig | 7 ++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 268 insertions(+) create mode 100644 drivers/video/backlight/led_bl.c
Here's the version of the driver I have. AFAICT default-brightness-level handling is ok, so does not need to be changed.
Lee, it would be easiest for me if you could apply it to your tree and push, but given enough time I can push it to Linus, too.
Oh you're using quoted-printable for patches.. Got it applied now, and it still works. Below is also the related dts change that I tested with.
Feel free to pick the dts change too, naturally that should not be applied before the driver.
If you guys instead want me to pick these both into my fixes branch, just let me know and I'll do the explaining why these are needed as fixes. Basically we no longer have a way to enable the LCD backlight for droid4 manually starting with v5.6-rc1 unlike earlier.
If you are willing to do that, it looks like good solution from my point of view.
OK. I'll apply them but won't push out yet in case Lee is already applying the driver change..
Pavel, care to ack the dts patch?
Regards,
Tony
Hi!
If you guys instead want me to pick these both into my fixes branch, just let me know and I'll do the explaining why these are needed as fixes. Basically we no longer have a way to enable the LCD backlight for droid4 manually starting with v5.6-rc1 unlike earlier.
If you are willing to do that, it looks like good solution from my point of view.
OK. I'll apply them but won't push out yet in case Lee is already applying the driver change..
Pavel, care to ack the dts patch?
It looks okay to me (but did not test it yet).
Acked-by: Pavel Machek pavel@ucw.cz
Thanks, Pavel
On Wed, Feb 19, 2020 at 11:45:40AM -0800, Tony Lindgren wrote:
- Pavel Machek pavel@ucw.cz [200219 19:15]:
From: Tomi Valkeinen tomi.valkeinen@ti.com
This patch adds a led-backlight driver (led_bl), which is similar to pwm_bl except the driver uses a LED class driver to adjust the brightness in the HW. Multiple LEDs can be used for a single backlight.
Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com Acked-by: Pavel Machek pavel@ucw.cz Reviewed-by: Daniel Thompson daniel.thompson@linaro.org Acked-by: Lee Jones lee.jones@linaro.org Acked-by: Tony Lindgren tony@atomide.com Tested-by: Tony Lindgren tony@atomide.com Signed-off-by: Pavel Machek pavel@ucw.cz
drivers/video/backlight/Kconfig | 7 ++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 268 insertions(+) create mode 100644 drivers/video/backlight/led_bl.c
Hi!
Here's the version of the driver I have. AFAICT default-brightness-level handling is ok, so does not need to be changed.
Lee, it would be easiest for me if you could apply it to your tree and push, but given enough time I can push it to Linus, too.
Oh you're using quoted-printable for patches.. Got it applied now, and it still works. Below is also the related dts change that I tested with.
Feel free to pick the dts change too, naturally that should not be applied before the driver.
If you guys instead want me to pick these both into my fixes branch, just let me know and I'll do the explaining why these are needed as fixes. Basically we no longer have a way to enable the LCD backlight for droid4 manually starting with v5.6-rc1 unlike earlier.
Regards,
Tony
8< ------------------ From tony Mon Sep 17 00:00:00 2001 From: Tony Lindgren tony@atomide.com Date: Wed, 19 Feb 2020 11:25:27 -0800 Subject: [PATCH] ARM: dts: droid4: Configure LED backlight for lm3532
With the LED backlight changes merged, we still need the dts configured to have backlight working for droid4. Based on an earlier patch from Pavel Machek pavel@ucw.cz, let's configure the backlight but update the value range to be more usable.
We have a range of 256 register values split into 8 steps, so we can generate the brightness levels backwards with:
$ for i in 0 1 2 3 4 5 6 7; do echo "255 - ${i} * (256 / 8)" | bc; done
To avoid more confusion why the LCD backlight is still not on, let's also enable LED backlight as a loadable module for omap2plus_defconfig.
Cc: Merlijn Wajer merlijn@wizzup.org Cc: Pavel Machek pavel@ucw.cz Signed-off-by: Tony Lindgren tony@atomide.com
arch/arm/boot/dts/motorola-mapphone-common.dtsi | 13 +++++++++++-- arch/arm/configs/omap2plus_defconfig | 1 + 2 files changed, 12 insertions(+), 2 deletions(-)
diff --git a/arch/arm/boot/dts/motorola-mapphone-common.dtsi b/arch/arm/boot/dts/motorola-mapphone-common.dtsi --- a/arch/arm/boot/dts/motorola-mapphone-common.dtsi +++ b/arch/arm/boot/dts/motorola-mapphone-common.dtsi @@ -182,6 +182,14 @@ vibrator { pwm-names = "enable", "direction"; direction-duty-cycle-ns = <10000000>; };
- backlight: backlight {
compatible = "led-backlight";leds = <&backlight_led>;brightness-levels = <31 63 95 127 159 191 223 255>;default-brightness-level = <6>;- };
};
&dss { @@ -205,6 +213,8 @@ lcd0: display { vddi-supply = <&lcd_regulator>; reset-gpios = <&gpio4 5 GPIO_ACTIVE_HIGH>; /* gpio101 */
backlight = <&backlight>;- width-mm = <50>; height-mm = <89>;
@@ -393,12 +403,11 @@ led-controller@38 { ramp-up-us = <1024>; ramp-down-us = <8193>;
led@0 {
backlight_led: led@0 { reg = <0>; led-sources = <2>; ti,led-mode = <0>; label = ":backlight";
linux,default-trigger = "backlight";};
led@1 {
diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig --- a/arch/arm/configs/omap2plus_defconfig +++ b/arch/arm/configs/omap2plus_defconfig @@ -375,6 +375,7 @@ CONFIG_BACKLIGHT_GENERIC=m CONFIG_BACKLIGHT_PWM=m CONFIG_BACKLIGHT_PANDORA=m CONFIG_BACKLIGHT_GPIO=m +CONFIG_BACKLIGHT_LED=m CONFIG_FRAMEBUFFER_CONSOLE=y CONFIG_FRAMEBUFFER_CONSOLE_ROTATION=y CONFIG_LOGO=y
Finally :)
Reviewed-by: Sebastian Reichel sebastian.reichel@collabora.com
-- Sebastian
* Sebastian Reichel sre@kernel.org [200219 23:45]:
Finally :)
Reviewed-by: Sebastian Reichel sebastian.reichel@collabora.com
Yeah thanks for your persistent effort on getting this working :)
Regards,
Tony
On Wed, 19 Feb 2020, Tony Lindgren wrote:
- Pavel Machek pavel@ucw.cz [200219 19:15]:
From: Tomi Valkeinen tomi.valkeinen@ti.com
This patch adds a led-backlight driver (led_bl), which is similar to pwm_bl except the driver uses a LED class driver to adjust the brightness in the HW. Multiple LEDs can be used for a single backlight.
Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com Acked-by: Pavel Machek pavel@ucw.cz Reviewed-by: Daniel Thompson daniel.thompson@linaro.org Acked-by: Lee Jones lee.jones@linaro.org Acked-by: Tony Lindgren tony@atomide.com Tested-by: Tony Lindgren tony@atomide.com Signed-off-by: Pavel Machek pavel@ucw.cz
drivers/video/backlight/Kconfig | 7 ++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 268 insertions(+) create mode 100644 drivers/video/backlight/led_bl.c
Hi!
Here's the version of the driver I have. AFAICT default-brightness-level handling is ok, so does not need to be changed.
Lee, it would be easiest for me if you could apply it to your tree and push, but given enough time I can push it to Linus, too.
Oh you're using quoted-printable for patches.. Got it applied now, and it still works. Below is also the related dts change that I tested with.
Feel free to pick the dts change too, naturally that should not be applied before the driver.
If you guys instead want me to pick these both into my fixes branch, just let me know and I'll do the explaining why these are needed as fixes. Basically we no longer have a way to enable the LCD backlight for droid4 manually starting with v5.6-rc1 unlike earlier.
Please do. You already have my Ack.
-- Lee Jones [李琼斯] Linaro Services Technical Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog
* Lee Jones lee.jones@linaro.org [200220 07:49]:
On Wed, 19 Feb 2020, Tony Lindgren wrote:
- Pavel Machek pavel@ucw.cz [200219 19:15]:
From: Tomi Valkeinen tomi.valkeinen@ti.com
This patch adds a led-backlight driver (led_bl), which is similar to pwm_bl except the driver uses a LED class driver to adjust the brightness in the HW. Multiple LEDs can be used for a single backlight.
Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com Acked-by: Pavel Machek pavel@ucw.cz Reviewed-by: Daniel Thompson daniel.thompson@linaro.org Acked-by: Lee Jones lee.jones@linaro.org Acked-by: Tony Lindgren tony@atomide.com Tested-by: Tony Lindgren tony@atomide.com Signed-off-by: Pavel Machek pavel@ucw.cz
drivers/video/backlight/Kconfig | 7 ++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 268 insertions(+) create mode 100644 drivers/video/backlight/led_bl.c
Hi!
Here's the version of the driver I have. AFAICT default-brightness-level handling is ok, so does not need to be changed.
Lee, it would be easiest for me if you could apply it to your tree and push, but given enough time I can push it to Linus, too.
Oh you're using quoted-printable for patches.. Got it applied now, and it still works. Below is also the related dts change that I tested with.
Feel free to pick the dts change too, naturally that should not be applied before the driver.
If you guys instead want me to pick these both into my fixes branch, just let me know and I'll do the explaining why these are needed as fixes. Basically we no longer have a way to enable the LCD backlight for droid4 manually starting with v5.6-rc1 unlike earlier.
Please do. You already have my Ack.
OK pushed out these two patches in omap-for-v5.6/droid4-lcd-fix.
Thanks,
Tony
Hi, On Wed, Feb 19, 2020 at 08:14:12PM +0100, Pavel Machek wrote:
From: Tomi Valkeinen tomi.valkeinen@ti.com
This patch adds a led-backlight driver (led_bl), which is similar to pwm_bl except the driver uses a LED class driver to adjust the brightness in the HW. Multiple LEDs can be used for a single backlight.
Signed-off-by: Tomi Valkeinen tomi.valkeinen@ti.com Signed-off-by: Jean-Jacques Hiblot jjhiblot@ti.com Acked-by: Pavel Machek pavel@ucw.cz Reviewed-by: Daniel Thompson daniel.thompson@linaro.org Acked-by: Lee Jones lee.jones@linaro.org Acked-by: Tony Lindgren tony@atomide.com Tested-by: Tony Lindgren tony@atomide.com Signed-off-by: Pavel Machek pavel@ucw.cz
Tested-by: Guido Günther agx@sigxcpu.org
Cheers, -- Guido
drivers/video/backlight/Kconfig | 7 ++ drivers/video/backlight/Makefile | 1 + drivers/video/backlight/led_bl.c | 260 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 268 insertions(+) create mode 100644 drivers/video/backlight/led_bl.c
Hi!
Here's the version of the driver I have. AFAICT default-brightness-level handling is ok, so does not need to be changed.
Lee, it would be easiest for me if you could apply it to your tree and push, but given enough time I can push it to Linus, too.
Thanks, Pavel
diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig index 403707a3e503..0093bbd0d326 100644 --- a/drivers/video/backlight/Kconfig +++ b/drivers/video/backlight/Kconfig @@ -456,6 +456,13 @@ config BACKLIGHT_RAVE_SP help Support for backlight control on RAVE SP device.
+config BACKLIGHT_LED
- tristate "Generic LED based Backlight Driver"
- depends on LEDS_CLASS && OF
- help
If you have a LCD backlight adjustable by LED class driver, say Yto enable this driver.endif # BACKLIGHT_CLASS_DEVICE
endmenu diff --git a/drivers/video/backlight/Makefile b/drivers/video/backlight/Makefile index 6f8777037c37..0c1a1524627a 100644 --- a/drivers/video/backlight/Makefile +++ b/drivers/video/backlight/Makefile @@ -57,3 +57,4 @@ obj-$(CONFIG_BACKLIGHT_TPS65217) += tps65217_bl.o obj-$(CONFIG_BACKLIGHT_WM831X) += wm831x_bl.o obj-$(CONFIG_BACKLIGHT_ARCXCNN) += arcxcnn_bl.o obj-$(CONFIG_BACKLIGHT_RAVE_SP) += rave-sp-backlight.o +obj-$(CONFIG_BACKLIGHT_LED) += led_bl.o diff --git a/drivers/video/backlight/led_bl.c b/drivers/video/backlight/led_bl.c new file mode 100644 index 000000000000..3f66549997c8 --- /dev/null +++ b/drivers/video/backlight/led_bl.c @@ -0,0 +1,260 @@ +// SPDX-License-Identifier: GPL-2.0 +/*
- Copyright (C) 2015-2019 Texas Instruments Incorporated - http://www.ti.com/
- Author: Tomi Valkeinen tomi.valkeinen@ti.com
- Based on pwm_bl.c
- */
+#include <linux/backlight.h> +#include <linux/leds.h> +#include <linux/module.h> +#include <linux/platform_device.h>
+struct led_bl_data {
- struct device *dev;
- struct backlight_device *bl_dev;
- struct led_classdev **leds;
- bool enabled;
- int nb_leds;
- unsigned int *levels;
- unsigned int default_brightness;
- unsigned int max_brightness;
+};
+static void led_bl_set_brightness(struct led_bl_data *priv, int level) +{
- int i;
- int bkl_brightness;
- if (priv->levels)
bkl_brightness = priv->levels[level];- else
bkl_brightness = level;- for (i = 0; i < priv->nb_leds; i++)
led_set_brightness(priv->leds[i], bkl_brightness);- priv->enabled = true;
+}
+static void led_bl_power_off(struct led_bl_data *priv) +{
- int i;
- if (!priv->enabled)
return;- for (i = 0; i < priv->nb_leds; i++)
led_set_brightness(priv->leds[i], LED_OFF);- priv->enabled = false;
+}
+static int led_bl_update_status(struct backlight_device *bl) +{
- struct led_bl_data *priv = bl_get_data(bl);
- int brightness = bl->props.brightness;
- if (bl->props.power != FB_BLANK_UNBLANK ||
bl->props.fb_blank != FB_BLANK_UNBLANK ||bl->props.state & BL_CORE_FBBLANK)brightness = 0;- if (brightness > 0)
led_bl_set_brightness(priv, brightness);- else
led_bl_power_off(priv);- return 0;
+}
+static const struct backlight_ops led_bl_ops = {
- .update_status = led_bl_update_status,
+};
+static int led_bl_get_leds(struct device *dev,
struct led_bl_data *priv)+{
- int i, nb_leds, ret;
- struct device_node *node = dev->of_node;
- struct led_classdev **leds;
- unsigned int max_brightness;
- unsigned int default_brightness;
- ret = of_count_phandle_with_args(node, "leds", NULL);
- if (ret < 0) {
dev_err(dev, "Unable to get led count\n");return -EINVAL;- }
- nb_leds = ret;
- if (nb_leds < 1) {
dev_err(dev, "At least one LED must be specified!\n");return -EINVAL;- }
- leds = devm_kzalloc(dev, sizeof(struct led_classdev *) * nb_leds,
GFP_KERNEL);- if (!leds)
return -ENOMEM;- for (i = 0; i < nb_leds; i++) {
leds[i] = devm_of_led_get(dev, i);if (IS_ERR(leds[i]))return PTR_ERR(leds[i]);- }
- /* check that the LEDs all have the same brightness range */
- max_brightness = leds[0]->max_brightness;
- for (i = 1; i < nb_leds; i++) {
if (max_brightness != leds[i]->max_brightness) {dev_err(dev, "LEDs must have identical ranges\n");return -EINVAL;}- }
- /* get the default brightness from the first LED from the list */
- default_brightness = leds[0]->brightness;
- priv->nb_leds = nb_leds;
- priv->leds = leds;
- priv->max_brightness = max_brightness;
- priv->default_brightness = default_brightness;
- return 0;
+}
+static int led_bl_parse_levels(struct device *dev,
struct led_bl_data *priv)+{
- struct device_node *node = dev->of_node;
- int num_levels;
- u32 value;
- int ret;
- if (!node)
return -ENODEV;- num_levels = of_property_count_u32_elems(node, "brightness-levels");
- if (num_levels > 1) {
int i;unsigned int db;u32 *levels = NULL;levels = devm_kzalloc(dev, sizeof(u32) * num_levels,GFP_KERNEL);if (!levels)return -ENOMEM;ret = of_property_read_u32_array(node, "brightness-levels",levels,num_levels);if (ret < 0)return ret;/** Try to map actual LED brightness to backlight brightness* level*/db = priv->default_brightness;for (i = 0 ; i < num_levels; i++) {if ((i && db > levels[i-1]) && db <= levels[i])break;}priv->default_brightness = i;priv->max_brightness = num_levels - 1;priv->levels = levels;- } else if (num_levels >= 0)
dev_warn(dev, "Not enough levels defined\n");- ret = of_property_read_u32(node, "default-brightness-level", &value);
- if (!ret && value <= priv->max_brightness)
priv->default_brightness = value;- else if (!ret && value > priv->max_brightness)
dev_warn(dev, "Invalid default brightness. Ignoring it\n");- return 0;
+}
+static int led_bl_probe(struct platform_device *pdev) +{
- struct backlight_properties props;
- struct led_bl_data *priv;
- int ret, i;
- priv = devm_kzalloc(&pdev->dev, sizeof(*priv), GFP_KERNEL);
- if (!priv)
return -ENOMEM;- platform_set_drvdata(pdev, priv);
- priv->dev = &pdev->dev;
- ret = led_bl_get_leds(&pdev->dev, priv);
- if (ret)
return ret;- ret = led_bl_parse_levels(&pdev->dev, priv);
- if (ret < 0) {
dev_err(&pdev->dev, "Failed to parse DT data\n");return ret;- }
- memset(&props, 0, sizeof(struct backlight_properties));
- props.type = BACKLIGHT_RAW;
- props.max_brightness = priv->max_brightness;
- props.brightness = priv->default_brightness;
- props.power = (priv->default_brightness > 0) ? FB_BLANK_POWERDOWN :
FB_BLANK_UNBLANK;- priv->bl_dev = backlight_device_register(dev_name(&pdev->dev),
&pdev->dev, priv, &led_bl_ops, &props);- if (IS_ERR(priv->bl_dev)) {
dev_err(&pdev->dev, "Failed to register backlight\n");return PTR_ERR(priv->bl_dev);- }
- for (i = 0; i < priv->nb_leds; i++)
led_sysfs_disable(priv->leds[i]);- backlight_update_status(priv->bl_dev);
- return 0;
+}
+static int led_bl_remove(struct platform_device *pdev) +{
- struct led_bl_data *priv = platform_get_drvdata(pdev);
- struct backlight_device *bl = priv->bl_dev;
- int i;
- backlight_device_unregister(bl);
- led_bl_power_off(priv);
- for (i = 0; i < priv->nb_leds; i++)
led_sysfs_enable(priv->leds[i]);- return 0;
+}
+static const struct of_device_id led_bl_of_match[] = {
- { .compatible = "led-backlight" },
- { }
+};
+MODULE_DEVICE_TABLE(of, led_bl_of_match);
+static struct platform_driver led_bl_driver = {
- .driver = {
.name = "led-backlight",.of_match_table = of_match_ptr(led_bl_of_match),- },
- .probe = led_bl_probe,
- .remove = led_bl_remove,
+};
+module_platform_driver(led_bl_driver);
+MODULE_DESCRIPTION("LED based Backlight Driver"); +MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:led-backlight");
2.11.0
dri-devel@lists.freedesktop.org
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Guido Günther -
Lee Jones -
Pavel Machek -
Sebastian Reichel -
Tony Lindgren