Hi,
On Thu, Oct 03, 2019 at 10:28:12AM +0200, Jean-Jacques Hiblot wrote:
> From: Tomi Valkeinen
>
> 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
> Signed-off-by: Jean-Jacques Hiblot
> Acked-by: Pavel Machek
> Reviewed-by: Daniel Thompson
> ---
Reviewed-by: Sebastian Reichel
(with some suggestions below)
> 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
>
> diff --git a/drivers/video/backlight/Kconfig b/drivers/video/backlight/Kconfig
> index 8b081d61773e..585a1787618c 100644
> --- a/drivers/video/backlight/Kconfig
> +++ b/drivers/video/backlight/Kconfig
> @@ -458,6 +458,13 @@ 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 63c507c07437..2a67642966a5 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 ..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
> + *
> + * Based on pwm_bl.c
> + */
> +
> +#include
> +#include
> +#include
> +#include
> +
> +struct led_bl_data {
> + struct device *dev;
> + struct backlight_device *bl_dev;
> + struct led_classdev **leds;
> + boolenabled;
> + int nb_leds;
> + unsigned int*levels;
> + unsigned intdefault_brightness;
> + unsigned intmax_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++) {
> +
