This patch adds a simple driver to handle all the LCD and LED powerup/down routines needed to support eDP/eDP-LVDS panels supported on exynos boards.
Most of the eDP/LVDS panels need this sequence for powerup: -- LCD unit powerup/LCD_EN -- video data on -- LED unit powerup/BL_EN
The LCD and LED units are usually powered up via regulators, and almost on all boards, we will have a BL_EN pin to enable/ disable the backlight. Sometimes, we can have LCD_EN switches as well. The routines in this driver can be used to control panel power sequence on such boards.
Signed-off-by: Ajay Kumar ajaykumar.rs@samsung.com --- .../devicetree/bindings/panel/exynos-dp-panel.txt | 32 ++++ drivers/gpu/drm/panel/Kconfig | 9 + drivers/gpu/drm/panel/Makefile | 1 + drivers/gpu/drm/panel/panel-exynos-dp.c | 213 +++++++++++++++++++++ 4 files changed, 255 insertions(+) create mode 100644 Documentation/devicetree/bindings/panel/exynos-dp-panel.txt create mode 100644 drivers/gpu/drm/panel/panel-exynos-dp.c
diff --git a/Documentation/devicetree/bindings/panel/exynos-dp-panel.txt b/Documentation/devicetree/bindings/panel/exynos-dp-panel.txt new file mode 100644 index 0000000..a1428d2 --- /dev/null +++ b/Documentation/devicetree/bindings/panel/exynos-dp-panel.txt @@ -0,0 +1,32 @@ +exynos_DP_panel/DP_to_LVDS_panel +================================== + +Required properties: + - compatible: "samsung,exynos-dp-panel" + +Optional properties: + -samsung,lcd-en-gpio: + eDP panel LCD poweron GPIO. + Indicates which GPIO needs to be powered up as output + to powerup/enable the switch to the LCD panel. + -samsung,led-en-gpio: + eDP panel LED enable GPIO. + Indicates which GPIO needs to be powered up as output + to enable the backlight. + -samsung,power-up-delay: + eDP panel powerup delay value in ms. + Delay in ms needed for the eDP panel to properly + powerup after giving powerup signals to the panel. + -samsung,power-down-delay: + eDP panel powerdown delay value in ms. + Delay in ms needed for the eDP panel to properly + powerdown after giving powerdown signals to the panel. + +Example: + + dp-panel { + compatible = "samsung,exynos-dp-panel"; + samsung,led-en-gpio = <&gpx3 0 1>; + samsung,power-up-delay = <40>; + samsung,power-down-delay = <50>; + }; diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig index 4ec874d..ea9d5ac 100644 --- a/drivers/gpu/drm/panel/Kconfig +++ b/drivers/gpu/drm/panel/Kconfig @@ -30,4 +30,13 @@ config DRM_PANEL_S6E8AA0 select DRM_MIPI_DSI select VIDEOMODE_HELPERS
+config DRM_PANEL_EXYNOS_DP + tristate "support for DP panels" + depends on OF && DRM_PANEL && DRM_EXYNOS_DP + help + DRM panel driver for DP panels and LVDS connected via DP bridges + that need at most a regulator for LCD unit, a regulator for LED unit + and/or enable GPIOs for LCD or LED units. Delay values can also be + specified to support powerup and powerdown process. + endmenu diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile index 8b92921..30311a4 100644 --- a/drivers/gpu/drm/panel/Makefile +++ b/drivers/gpu/drm/panel/Makefile @@ -1,3 +1,4 @@ obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o obj-$(CONFIG_DRM_PANEL_LD9040) += panel-ld9040.o obj-$(CONFIG_DRM_PANEL_S6E8AA0) += panel-s6e8aa0.o +obj-$(CONFIG_DRM_PANEL_EXYNOS_DP) += panel-exynos-dp.o diff --git a/drivers/gpu/drm/panel/panel-exynos-dp.c b/drivers/gpu/drm/panel/panel-exynos-dp.c new file mode 100644 index 0000000..e85a7b2 --- /dev/null +++ b/drivers/gpu/drm/panel/panel-exynos-dp.c @@ -0,0 +1,213 @@ +/* + * Exynos DP panel driver + * + * Copyright (c) 2014 Samsung Electronics Co., Ltd + * + * Ajay Kumar ajaykumar.rs@samsung.com + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/component.h> +#include <linux/gpio.h> +#include <linux/module.h> +#include <linux/of_gpio.h> +#include <linux/of_platform.h> +#include <linux/platform_device.h> +#include <linux/regulator/consumer.h> + +#include <drm/drmP.h> +#include <drm/drm_crtc.h> +#include <drm/drm_panel.h> + +struct panel_exynos_dp { + struct drm_panel base; + struct regulator *bck_fet; + struct regulator *lcd_fet; + int led_en_gpio; + int lcd_en_gpio; + int power_up_delay; + int power_down_delay; + bool enabled; +}; + +static inline struct panel_exynos_dp *to_panel(struct drm_panel *panel) +{ + return container_of(panel, struct panel_exynos_dp, base); +} + +static int panel_exynos_dp_disable(struct drm_panel *panel) +{ + struct panel_exynos_dp *dp_panel = to_panel(panel); + bool enable_delay = false; + + if (!dp_panel->enabled) + return 0; + + if (gpio_is_valid(dp_panel->led_en_gpio)) + gpio_set_value(dp_panel->led_en_gpio, 0); + + if (!IS_ERR_OR_NULL(dp_panel->bck_fet)) + regulator_disable(dp_panel->bck_fet); + + if (gpio_is_valid(dp_panel->lcd_en_gpio)) { + gpio_set_value(dp_panel->lcd_en_gpio, 0); + enable_delay = true; + } + + if (!IS_ERR_OR_NULL(dp_panel->lcd_fet)) { + regulator_disable(dp_panel->lcd_fet); + enable_delay = true; + } + + if (enable_delay) + msleep(dp_panel->power_down_delay); + + dp_panel->enabled = false; + + return 0; +} + +static int panel_exynos_dp_pre_enable(struct drm_panel *panel) +{ + struct panel_exynos_dp *dp_panel = to_panel(panel); + bool enable_delay = false; + + if (dp_panel->enabled) + return 0; + + if (!IS_ERR_OR_NULL(dp_panel->lcd_fet)) { + if (regulator_enable(dp_panel->lcd_fet)) + DRM_ERROR("Failed to enable LCD fet\n"); + enable_delay = true; + } + + if (gpio_is_valid(dp_panel->lcd_en_gpio)) { + gpio_set_value(dp_panel->lcd_en_gpio, 1); + enable_delay = true; + } + + if (enable_delay) + msleep(dp_panel->power_up_delay); + + return 0; +} + +static int panel_exynos_dp_enable(struct drm_panel *panel) +{ + struct panel_exynos_dp *dp_panel = to_panel(panel); + + if (dp_panel->enabled) + return 0; + + if (!IS_ERR_OR_NULL(dp_panel->bck_fet)) + if (regulator_enable(dp_panel->bck_fet)) + DRM_ERROR("Failed to enable LED fet\n"); + + if (gpio_is_valid(dp_panel->led_en_gpio)) + gpio_set_value(dp_panel->led_en_gpio, 1); + + dp_panel->enabled = true; + + return 0; +} + +static const struct drm_panel_funcs panel_exynos_dp_funcs = { + .disable = panel_exynos_dp_disable, + .pre_enable = panel_exynos_dp_pre_enable, + .enable = panel_exynos_dp_enable, +}; + +static int panel_exynos_dp_probe(struct platform_device *pdev) +{ + struct panel_exynos_dp *dp_panel; + struct device *dev = &pdev->dev; + int ret; + + dp_panel = devm_kzalloc(dev, sizeof(*dp_panel), GFP_KERNEL); + if (!dp_panel) + return -ENOMEM; + + dp_panel->enabled = false; + + dp_panel->lcd_en_gpio = of_get_named_gpio(dev->of_node, + "samsung,lcd-en-gpio", 0); + dp_panel->led_en_gpio = of_get_named_gpio(dev->of_node, + "samsung,led-en-gpio", 0); + + of_property_read_u32(dev->of_node, "samsung,power-up-delay", + &dp_panel->power_up_delay); + of_property_read_u32(dev->of_node, "samsung,power-down-delay", + &dp_panel->power_down_delay); + + dp_panel->lcd_fet = devm_regulator_get(dev, "lcd_vdd"); + if (IS_ERR(dp_panel->lcd_fet)) + return PTR_ERR(dp_panel->lcd_fet); + + dp_panel->bck_fet = devm_regulator_get(dev, "vcd_led"); + if (IS_ERR(dp_panel->bck_fet)) + return PTR_ERR(dp_panel->bck_fet); + + if (gpio_is_valid(dp_panel->lcd_en_gpio)) { + ret = devm_gpio_request_one(dev, dp_panel->lcd_en_gpio, + GPIOF_OUT_INIT_LOW, "lcd_en_gpio"); + if (ret) { + DRM_ERROR("failed to get lcd-en gpio [%d]\n", ret); + return ret; + } + } else { + dp_panel->lcd_en_gpio = -ENODEV; + } + + if (gpio_is_valid(dp_panel->led_en_gpio)) { + ret = devm_gpio_request_one(dev, dp_panel->led_en_gpio, + GPIOF_OUT_INIT_LOW, "led_en_gpio"); + if (ret) { + DRM_ERROR("failed to get led-en gpio [%d]\n", ret); + return ret; + } + } else { + dp_panel->led_en_gpio = -ENODEV; + } + + drm_panel_init(&dp_panel->base); + dp_panel->base.dev = dev; + dp_panel->base.funcs = &panel_exynos_dp_funcs; + + ret = drm_panel_add(&dp_panel->base); + if (ret < 0) + return ret; + + dev_set_drvdata(dev, dp_panel); + + return 0; +} + +static int panel_exynos_dp_remove(struct platform_device *pdev) +{ + struct panel_exynos_dp *dp_panel = dev_get_drvdata(&pdev->dev); + + drm_panel_detach(&dp_panel->base); + drm_panel_remove(&dp_panel->base); + + panel_exynos_dp_disable(&dp_panel->base); + + return 0; +} + +static const struct of_device_id exynos_dp_panel_dt_match[] = { + { .compatible = "samsung,exynos-dp-panel" }, + {}, +}; + +struct platform_driver exynos_dp_panel_driver = { + .driver = { + .name = "exynos-dp-panel", + .owner = THIS_MODULE, + .of_match_table = exynos_dp_panel_dt_match, + }, + .probe = panel_exynos_dp_probe, + .remove = panel_exynos_dp_remove, +};