Hello Alex,
On Sat, Jan 19, 2013 at 4:00 PM, Alexandre Courbot <acourbot@xxxxxxxxxx> wrote:
>
> Add a PWM-backlight subdriver for Tegra boards, with support for
> Ventana.
>
> Signed-off-by: Alexandre Courbot <acourbot@xxxxxxxxxx>
> ---
> arch/arm/boot/dts/tegra20-ventana.dts | 18 +++-
> arch/arm/configs/tegra_defconfig | 1 +
> drivers/video/backlight/Kconfig | 7 ++
> drivers/video/backlight/pwm_bl.c | 3 +
> drivers/video/backlight/pwm_bl_tegra.c | 159
> +++++++++++++++++++++++++++++++++
> 5 files changed, 186 insertions(+), 2 deletions(-)
> create mode 100644 drivers/video/backlight/pwm_bl_tegra.c
>
> diff --git a/arch/arm/boot/dts/tegra20-ventana.dts
> b/arch/arm/boot/dts/tegra20-ventana.dts
> index adc4754..a77b529 100644
> --- a/arch/arm/boot/dts/tegra20-ventana.dts
> +++ b/arch/arm/boot/dts/tegra20-ventana.dts
> @@ -516,6 +516,20 @@
> bus-width = <8>;
> };
>
> + backlight {
> + compatible = "pwm-backlight-ventana";
> + brightness-levels = <0 16 32 48 64 80 96 112 128 144 160
> 176 192 208 224 240 255>;
> + default-brightness-level = <12>;
> +
> + pwms = <&pwm 2 5000000>;
> + pwm-names = "backlight";
> +
> + power-supply = <&vdd_bl_reg>;
> + panel-supply = <&vdd_pnl_reg>;
> + bl-gpio = <&gpio 28 0>;
> + bl-panel = <&gpio 10 0>;
> + };
> +
> regulators {
> compatible = "simple-bus";
> #address-cells = <1>;
> @@ -549,7 +563,7 @@
> enable-active-high;
> };
>
> - regulator@3 {
> + vdd_pnl_reg: regulator@3 {
> compatible = "regulator-fixed";
> reg = <3>;
> regulator-name = "vdd_pnl";
> @@ -559,7 +573,7 @@
> enable-active-high;
> };
>
> - regulator@4 {
> + vdd_bl_reg: regulator@4 {
> compatible = "regulator-fixed";
> reg = <4>;
> regulator-name = "vdd_bl";
> diff --git a/arch/arm/configs/tegra_defconfig
> b/arch/arm/configs/tegra_defconfig
> index a7827fd..1c46602 100644
> --- a/arch/arm/configs/tegra_defconfig
> +++ b/arch/arm/configs/tegra_defconfig
> @@ -150,6 +150,7 @@ CONFIG_BACKLIGHT_LCD_SUPPORT=y
> CONFIG_BACKLIGHT_CLASS_DEVICE=y
> # CONFIG_BACKLIGHT_GENERIC is not set
> CONFIG_BACKLIGHT_PWM=y
> +CONFIG_BACKLIGHT_PWM_TEGRA=y
> CONFIG_FRAMEBUFFER_CONSOLE=y
> CONFIG_LOGO=y
> CONFIG_SOUND=y
> diff --git a/drivers/video/backlight/Kconfig
> b/drivers/video/backlight/Kconfig
> index 765a945..377a409 100644
> --- a/drivers/video/backlight/Kconfig
> +++ b/drivers/video/backlight/Kconfig
> @@ -244,6 +244,13 @@ config BACKLIGHT_PWM
> If you have a LCD backlight adjustable by PWM, say Y to enable
> this driver.
>
> +config BACKLIGHT_PWM_TEGRA
> + bool "PWM Backlight Driver for Tegra boards"
> + depends on BACKLIGHT_PWM && ARCH_TEGRA
> + help
> + Support backlight power sequencing for Tegra boards.
> + Supported boards: Ventana.
> +
> config BACKLIGHT_DA903X
> tristate "Backlight Driver for DA9030/DA9034 using WLED"
> depends on PMIC_DA903X
> diff --git a/drivers/video/backlight/pwm_bl.c
> b/drivers/video/backlight/pwm_bl.c
> index b65a797..1a4a9a3 100644
> --- a/drivers/video/backlight/pwm_bl.c
> +++ b/drivers/video/backlight/pwm_bl.c
> @@ -217,6 +217,9 @@ static int pwm_backlight_parse_dt(struct device *dev,
>
> static struct of_device_id pwm_backlight_of_match[] = {
> { .compatible = "pwm-backlight" },
> +#ifdef CONFIG_BACKLIGHT_PWM_TEGRA
> + { .compatible = "pwm-backlight-ventana" },
> +#endif
> { }
> };
>
> diff --git a/drivers/video/backlight/pwm_bl_tegra.c
> b/drivers/video/backlight/pwm_bl_tegra.c
> new file mode 100644
> index 0000000..8f2195b
> --- /dev/null
> +++ b/drivers/video/backlight/pwm_bl_tegra.c
> @@ -0,0 +1,159 @@
> +/*
> + * pwm-backlight subdriver for Tegra.
> + *
> + * Copyright (c) 2013 NVIDIA CORPORATION. All rights reserved.
> + *
> + * This software is licensed under the terms of the GNU General Public
> + * License version 2, as published by the Free Software Foundation, and
> + * may be copied, distributed, and modified under those terms.
> + *
> + * This program is distributed in the hope that it will be useful,
> + * but WITHOUT ANY WARRANTY; without even the implied warranty of
> + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
> + * GNU General Public License for more details.
> + *
> + */
> +#include <linux/err.h>
> +#include <linux/module.h>
> +#include <linux/pwm_backlight.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/gpio.h>
> +#include <linux/of_gpio.h>
> +#include <linux/list.h>
> +#include <linux/delay.h>
> +#include <linux/slab.h>
> +
> +struct ventana_bl_data {
> + struct regulator *vdd_power;
> + struct regulator *vdd_panel;
> + int bl_gpio;
> + int panel_gpio;
> + bool is_on;
> +};
> +
> +static int init_ventana(struct device *dev)
> +{
> + struct ventana_bl_data *data;
> + int ret;
> +
> + data = devm_kzalloc(dev, sizeof(struct ventana_bl_data),
> GFP_KERNEL);
> + if (!data)
> + return -ENOMEM;
> +
> + data->vdd_power = devm_regulator_get(dev, "power");
> + if (IS_ERR(data->vdd_power)) {
> + dev_err(dev, "cannot get power regulator!\n");
> + return PTR_ERR(data->vdd_power);
> + }
> +
> + data->vdd_panel = devm_regulator_get(dev, "panel");
> + if (IS_ERR(data->vdd_panel)) {
> + dev_err(dev, "cannot get panel regulator!\n");
> + return PTR_ERR(data->vdd_panel);
> + }
> +
> + ret = of_get_named_gpio(dev->of_node, "bl-gpio", 0);
> + if (ret < 0) {
> + dev_err(dev, "cannot find backlight GPIO!\n");
> + return ret;
> + }
> + data->bl_gpio = ret;
> +
> + ret = of_get_named_gpio(dev->of_node, "bl-panel", 0);
> + if (ret < 0) {
> + dev_err(dev, "cannot find panel GPIO!\n");
> + return ret;
> + }
> + data->panel_gpio = ret;
> +
> + ret = devm_gpio_request_one(dev, data->bl_gpio,
> + GPIOF_DIR_OUT | GPIOF_OUT_INIT_LOW,
> + "backlight");
> + if (ret < 0) {
> + dev_err(dev, "cannot request backlight GPIO!\n");
> + return ret;
> + }
> +
> + ret = devm_gpio_request_one(dev, data->panel_gpio,
> + GPIOF_DIR_OUT | GPIOF_OUT_INIT_LOW,
> + "panel");
> + if (ret < 0) {
> + dev_err(dev, "cannot request panel GPIO!\n");
> + return ret;
> + }
> +
> + pwm_backlight_set_subdriver_data(dev, data);
Here you are passing ventana_bl_data pointer as input and in the
pwm_backlight_get_subdriver_data() function you are assigning the
received driver data to backlight_device pointer. As both are two
different structures with different structure fields in it. There can
be a chance for a crash.
Please correct me if I'm wrong.
Best Wishes,
Leela Krishna Amudala.
> +
> + return 0;
> +}
> +
> +static void exit_ventana(struct device *dev)
> +{
> + struct ventana_bl_data *data =
> pwm_backlight_get_subdriver_data(dev);
> +
> + devm_gpio_free(dev, data->panel_gpio);
> + devm_gpio_free(dev, data->bl_gpio);
> + devm_regulator_put(data->vdd_panel);
> + devm_regulator_put(data->vdd_power);
> + devm_kfree(dev, data);
> +}
> +
> +static int notify_ventana(struct device *dev, int brightness)
> +{
> + struct ventana_bl_data *data =
> pwm_backlight_get_subdriver_data(dev);
> + if (brightness && !data->is_on) {
> + regulator_enable(data->vdd_panel);
> + gpio_set_value(data->panel_gpio, 1);
> + usleep_range(200000, 200000);
> + regulator_enable(data->vdd_power);
> + usleep_range(10000, 10000);
> + } else if (!brightness && data->is_on) {
> + gpio_set_value(data->bl_gpio, 0);
> + }
> +
> + return brightness;
> +}
> +
> +static void notify_after_ventana(struct device *dev, int brightness)
> +{
> + struct ventana_bl_data *data =
> pwm_backlight_get_subdriver_data(dev);
> + if (brightness && !data->is_on) {
> + gpio_set_value(data->bl_gpio, 1);
> + data->is_on = true;
> + } else if (!brightness && data->is_on) {
> + usleep_range(10000, 10000);
> + regulator_disable(data->vdd_power);
> + usleep_range(200000, 200000);
> + gpio_set_value(data->panel_gpio, 0);
> + regulator_disable(data->vdd_panel);
> + data->is_on = false;
> + }
> +}
> +
> +static struct pwm_backlight_subdriver pwm_backlight_ventana_subdriver = {
> + .name = "pwm-backlight-ventana",
> + .init = init_ventana,
> + .exit = exit_ventana,
> + .notify = notify_ventana,
> + .notify_after = notify_after_ventana,
> +};
> +
> +static int __init pwm_backlight_tegra_init(void)
> +{
> + pwm_backlight_add_subdriver(&pwm_backlight_ventana_subdriver);
> + return 0;
> +}
> +
> +static void __exit pwm_backlight_tegra_exit(void)
> +{
> + pwm_backlight_remove_subdriver(&pwm_backlight_ventana_subdriver);
> +}
> +
> +module_init(pwm_backlight_tegra_init);
> +module_exit(pwm_backlight_tegra_exit);
> +
> +MODULE_DESCRIPTION("Backlight Driver for Tegra boards");
> +MODULE_LICENSE("GPL");
> +MODULE_ALIAS("platform:pwm-tegra-backlight");
> +
> +
> --
> 1.8.1.1
>
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