Hi Jingoo, On Fri, Apr 18, 2014 at 2:17 PM, Jingoo Han wrote: > On Wednesday, April 16, 2014 11:33 PM, Ajay Kumar wrote: > > > > 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 > > --- > > .../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 > > Please remove unnecessary under lines as below. > > Ok. > 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 > > + * > > + * 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 > > +#include > > +#include > > +#include > > +#include > > +#include > > +#include > > + > > +#include > > +#include > > +#include > > + > > +struct panel_exynos_dp { > > + struct drm_panel base; > > + struct regulator *bck_fet; > > + struct regulator *lcd_fet; > > 'bck' means 'backlight'? Then, just use 'backlight_fet'. > backlight_fet is more meaningful. Will change it. Also, I cannot understand the meaning of 'fet'. > What's the meaning of the 'fet'? > > FET is an output from the regulator. On exynos5250-snow board, FET1 controls power to the backlight unit. See more here: https://lkml.org/lkml/2014/4/15/618 > + 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) > > panel_exynos_dp_pre_enable() always returns '0'. > These are two ways. Either one will be better. > 1. Make return values meaningful. In other words, add the case > returning error values. > > 2. Change the return type to 'void' > > Ok. Will add a check for all failure cases. > > +{ > > + 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, > > +}; > > -- > > 1.8.1.2 > > Thanks and regards, Ajay Kumar