Hi Javier, Thanks for the review.
On Mon, Jun 23, 2014 at 11:30 AM, Javier Martinez Canillas <jav...@dowhile0.org> wrote: > Hello Ajay, > > Not an extensive review since I'm not familiar with the graphics stack > but a few things I noticed are commented below. > > On Wed, Jun 11, 2014 at 8:27 PM, Ajay Kumar <ajaykumar...@samsung.com> wrote: >> This patch adds a simple driver to handle all the LCD and LED >> powerup/down routines needed to support eDP/LVDS panels. >> >> The LCD and LED units are usually powered up via regulators, >> and almost on all boards, we will have a BACKLIGHT_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...@samsung.com> >> Signed-off-by: Rahul Sharma <rahul.sha...@samsung.com> >> --- >> .../devicetree/bindings/panel/panel-lvds.txt | 50 ++++ >> drivers/gpu/drm/panel/Kconfig | 10 + >> drivers/gpu/drm/panel/Makefile | 1 + >> drivers/gpu/drm/panel/panel-lvds.c | 262 >> ++++++++++++++++++++ >> 4 files changed, 323 insertions(+) >> create mode 100644 Documentation/devicetree/bindings/panel/panel-lvds.txt >> create mode 100644 drivers/gpu/drm/panel/panel-lvds.c >> >> diff --git a/Documentation/devicetree/bindings/panel/panel-lvds.txt >> b/Documentation/devicetree/bindings/panel/panel-lvds.txt >> new file mode 100644 >> index 0000000..7cb6084 >> --- /dev/null >> +++ b/Documentation/devicetree/bindings/panel/panel-lvds.txt >> @@ -0,0 +1,50 @@ >> +panel interface for eDP/lvds panels >> + >> +Required properties: >> + - compatible: "panel-lvds" >> + >> +Optional properties: >> + -lcd-en-gpio: >> + panel LCD poweron GPIO. >> + Indicates which GPIO needs to be powered up as output >> + to powerup/enable the switch to the LCD panel. >> + -led-en-gpio: >> + panel LED enable GPIO. >> + Indicates which GPIO needs to be powered up as output >> + to enable the backlight. >> + -panel-prepare-delay: >> + delay value in ms required for panel_prepare process >> + Delay in ms needed for the panel LCD unit to >> + powerup completely. >> + ex: delay needed till eDP panel throws HPD. >> + delay needed so that we cans tart reading edid. >> + -panel-enable-delay: >> + delay value in ms required for panel_enable process >> + Delay in ms needed for the panel backlight/LED unit >> + to powerup, and delay needed between video_enable and >> + backlight_enable. >> + -panel-disable-delay: >> + delay value in ms required for panel_disable process >> + Delay in ms needed for the panel backlight/LED unit >> + powerdown, and delay needed between backlight_disable >> + and video_disable. >> + -panel-unprepare-delay: >> + delay value in ms required for panel_post_disable process >> + Delay in ms needed for the panel LCD unit to >> + to powerdown completely, and the minimum delay needed >> + before powering it on again. >> + -panel-width-mm: physical panel width [mm] >> + -panel-height-mm: physical panel height [mm] >> + >> +Example: >> + >> + panel-lvds { >> + compatible = "panel-lvds"; >> + led-en-gpio = <&gpx3 0 1>; >> + panel-prepare-delay = <40>; >> + panel-enable-delay = <20>; >> + panel-disable-delay = <20>; >> + panel-unprepare-delay = <30>; >> + panel-width-mm = <256>; >> + panel-height-mm = <144>; >> + }; > > Recently it's considered a good practice to have the DT binding > documentation in a separate patch. Ok, will remember this. >> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig >> index 4ec874d..8fe7ee5 100644 >> --- a/drivers/gpu/drm/panel/Kconfig >> +++ b/drivers/gpu/drm/panel/Kconfig >> @@ -30,4 +30,14 @@ config DRM_PANEL_S6E8AA0 >> select DRM_MIPI_DSI >> select VIDEOMODE_HELPERS >> >> +config DRM_PANEL_EDP_LVDS >> + tristate "support for eDP/LVDS panels" >> + depends on OF && DRM_PANEL >> + select VIDEOMODE_HELPERS >> + help >> + DRM panel driver for direct eDP panels or 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..eaafa01 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_EDP_LVDS) += panel-lvds.o >> diff --git a/drivers/gpu/drm/panel/panel-lvds.c >> b/drivers/gpu/drm/panel/panel-lvds.c >> new file mode 100644 >> index 0000000..2124fcb >> --- /dev/null >> +++ b/drivers/gpu/drm/panel/panel-lvds.c >> @@ -0,0 +1,262 @@ >> +/* >> + * panel driver for lvds and eDP panels >> + * >> + * Copyright (c) 2014 Samsung Electronics Co., Ltd >> + * >> + * Ajay Kumar <ajaykumar...@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/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 <video/of_videomode.h> >> +#include <video/videomode.h> >> + >> +#include <drm/drmP.h> >> +#include <drm/drm_crtc.h> >> +#include <drm/drm_panel.h> >> + >> +struct panel_lvds { >> + struct drm_panel base; >> + struct regulator *backlight_fet; >> + struct regulator *lcd_fet; >> + struct videomode vm; >> + int width_mm; >> + int height_mm; >> + bool backlight_fet_enabled; >> + bool lcd_fet_enabled; >> + int led_en_gpio; >> + int lcd_en_gpio; >> + int panel_prepare_delay; >> + int panel_enable_delay; >> + int panel_disable_delay; >> + int panel_unprepare_delay; >> +}; >> + >> +static inline struct panel_lvds *to_panel(struct drm_panel *panel) >> +{ >> + return container_of(panel, struct panel_lvds, base); >> +} >> + >> +static int panel_lvds_prepare(struct drm_panel *panel) >> +{ >> + struct panel_lvds *lvds_panel = to_panel(panel); >> + >> + if (!IS_ERR_OR_NULL(lvds_panel->lcd_fet)) >> + if (!lvds_panel->lcd_fet_enabled) { >> + if (regulator_enable(lvds_panel->lcd_fet)) >> + DRM_ERROR("failed to enable LCD fet\n"); >> + lvds_panel->lcd_fet_enabled = true; > > If this is an expected condition then using DRM_INFO() instead? It > looks like an error to me though so maybe should return an error in > this case? Right, we should ideally return an error here. >> + } >> + >> + if (gpio_is_valid(lvds_panel->lcd_en_gpio)) >> + gpio_set_value(lvds_panel->lcd_en_gpio, 1); >> + >> + msleep(lvds_panel->panel_prepare_delay); >> + >> + return 0; >> +} >> + >> +static int panel_lvds_enable(struct drm_panel *panel) >> +{ >> + struct panel_lvds *lvds_panel = to_panel(panel); >> + >> + if (!IS_ERR_OR_NULL(lvds_panel->backlight_fet)) >> + if (!lvds_panel->backlight_fet_enabled) { >> + if (regulator_enable(lvds_panel->backlight_fet)) >> + DRM_ERROR("failed to enable LED fet\n"); >> + lvds_panel->backlight_fet_enabled = true; > > Same here. Ok. >> + } >> + >> + msleep(lvds_panel->panel_enable_delay); >> + >> + if (gpio_is_valid(lvds_panel->led_en_gpio)) >> + gpio_set_value(lvds_panel->led_en_gpio, 1); >> + >> + return 0; >> +} >> + >> +static int panel_lvds_disable(struct drm_panel *panel) >> +{ >> + struct panel_lvds *lvds_panel = to_panel(panel); >> + >> + if (gpio_is_valid(lvds_panel->led_en_gpio)) >> + gpio_set_value(lvds_panel->led_en_gpio, 0); >> + >> + if (!IS_ERR_OR_NULL(lvds_panel->backlight_fet)) >> + if (lvds_panel->backlight_fet_enabled) { >> + regulator_disable(lvds_panel->backlight_fet); >> + lvds_panel->backlight_fet_enabled = false; >> + } >> + >> + msleep(lvds_panel->panel_disable_delay); >> + >> + return 0; >> +} >> + >> +static int panel_lvds_unprepare(struct drm_panel *panel) >> +{ >> + struct panel_lvds *lvds_panel = to_panel(panel); >> + >> + if (gpio_is_valid(lvds_panel->lcd_en_gpio)) >> + gpio_set_value(lvds_panel->lcd_en_gpio, 0); >> + >> + if (!IS_ERR_OR_NULL(lvds_panel->lcd_fet)) >> + if (lvds_panel->lcd_fet_enabled) { >> + regulator_disable(lvds_panel->lcd_fet); >> + lvds_panel->lcd_fet_enabled = false; >> + } >> + >> + msleep(lvds_panel->panel_unprepare_delay); >> + >> + return 0; >> +} >> + >> +static int panel_lvds_get_modes(struct drm_panel *panel) >> +{ >> + struct drm_connector *connector = panel->connector; >> + struct panel_lvds *lvds_panel = to_panel(panel); >> + struct drm_display_mode *mode; >> + >> + mode = drm_mode_create(connector->dev); >> + if (!mode) { >> + DRM_ERROR("failed to create a new display mode.\n"); >> + return 0; >> + } >> + >> + drm_display_mode_from_videomode(&lvds_panel->vm, mode); >> + mode->width_mm = lvds_panel->width_mm; >> + mode->height_mm = lvds_panel->height_mm; >> + connector->display_info.width_mm = mode->width_mm; >> + connector->display_info.height_mm = mode->height_mm; >> + >> + mode->type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED; >> + drm_mode_set_name(mode); >> + drm_mode_probed_add(connector, mode); >> + >> + return 1; >> +} >> + >> +static const struct drm_panel_funcs panel_lvds_funcs = { >> + .unprepare = panel_lvds_unprepare, >> + .disable = panel_lvds_disable, >> + .prepare = panel_lvds_prepare, >> + .enable = panel_lvds_enable, >> + .get_modes = panel_lvds_get_modes, >> +}; >> + >> +static int panel_lvds_probe(struct platform_device *pdev) >> +{ >> + struct panel_lvds *panel; >> + struct device *dev = &pdev->dev; >> + struct device_node *node = dev->of_node; >> + int ret; >> + >> + panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL); >> + if (!panel) >> + return -ENOMEM; >> + >> + ret = of_get_videomode(node, &panel->vm, 0); >> + if (ret) { >> + DRM_ERROR("failed: of_get_videomode() : %d\n", ret); >> + return ret; >> + } >> + >> + panel->lcd_fet = devm_regulator_get_optional(dev, "lcd_vdd"); >> + if (IS_ERR(panel->lcd_fet)) >> + return -EPROBE_DEFER; >> + >> + panel->backlight_fet = devm_regulator_get_optional(dev, "vcd_led"); >> + if (IS_ERR(panel->backlight_fet)) >> + return -EPROBE_DEFER; >> + >> + panel->lcd_en_gpio = of_get_named_gpio(node, "lcd-en-gpio", 0); >> + panel->led_en_gpio = of_get_named_gpio(node, "led-en-gpio", 0); >> + > > The old integer-based GPIO API has been deprecated and new drivers > should use the new descriptor-based interface > (Documentation/gpio/consumer.txt) instead if possible. Ok, I just saw other panel drivers using the same. Will change this. >> + of_property_read_u32(node, "panel-width-mm", &panel->width_mm); >> + of_property_read_u32(node, "panel-height-mm", &panel->height_mm); >> + >> + of_property_read_u32(node, "panel-prepare-delay", >> + &panel->panel_prepare_delay); >> + of_property_read_u32(node, "panel-enable-delay", >> + &panel->panel_enable_delay); >> + of_property_read_u32(node, "panel-disable-delay", >> + &panel->panel_disable_delay); >> + of_property_read_u32(node, "panel-unprepare-delay", >> + &panel->panel_unprepare_delay); >> + >> + if (gpio_is_valid(panel->lcd_en_gpio)) { >> + ret = devm_gpio_request_one(dev, 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 0; > > The probe() function returning 0 means success to the driver core but > here is returning early due an error. Right, will fix it. >> + } >> + } else { >> + panel->lcd_en_gpio = -ENODEV; >> + } >> + >> + if (gpio_is_valid(panel->led_en_gpio)) { >> + ret = devm_gpio_request_one(dev, 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 0; > > Same here, it should return an error code instead 0. Right, will fix it. >> + } >> + } else { >> + panel->led_en_gpio = -ENODEV; >> + } >> + >> + drm_panel_init(&panel->base); >> + panel->base.dev = dev; >> + panel->base.funcs = &panel_lvds_funcs; >> + >> + ret = drm_panel_add(&panel->base); >> + if (ret < 0) >> + return ret; >> + >> + dev_set_drvdata(dev, panel); >> + >> + return 0; >> +} >> + >> +static int panel_lvds_remove(struct platform_device *pdev) >> +{ >> + struct panel_lvds *panel = dev_get_drvdata(&pdev->dev); >> + >> + panel_lvds_disable(&panel->base); >> + panel_lvds_unprepare(&panel->base); >> + >> + drm_panel_remove(&panel->base); >> + >> + return 0; >> +} >> + >> +static const struct of_device_id lvds_panel_dt_match[] = { >> + { .compatible = "panel-lvds" }, >> + {}, >> +}; >> +MODULE_DEVICE_TABLE(of, lvds_panel_dt_match); >> + >> +struct platform_driver lvds_panel_driver = { >> + .driver = { >> + .name = "panel_lvds", >> + .owner = THIS_MODULE, >> + .of_match_table = lvds_panel_dt_match, >> + }, >> + .probe = panel_lvds_probe, >> + .remove = panel_lvds_remove, >> +}; >> +module_platform_driver(lvds_panel_driver); >> + >> +MODULE_AUTHOR("Ajay Kumar <ajaykumar...@samsung.com>"); >> +MODULE_DESCRIPTION("lvds/eDP panel driver"); >> +MODULE_LICENSE("GPL v2"); >> -- >> 1.7.9.5 >> > > Best regards, > Javier -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html