Add a PWM-backlight subdriver for Tegra boards, with support for
Ventana.
Signed-off-by: Alexandre Courbot <acour...@nvidia.com>
---
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);
+
+ 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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