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.rs at samsung.com>
Signed-off-by: Rahul Sharma <Rahul.Sharma at samsung.com>
---
drivers/gpu/drm/panel/Kconfig | 10 ++
drivers/gpu/drm/panel/Makefile | 1 +
drivers/gpu/drm/panel/panel-lvds.c | 268 ++++++++++++++++++++++++++++++++++++
3 files changed, 279 insertions(+)
create mode 100644 drivers/gpu/drm/panel/panel-lvds.c
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..ce20587
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-lvds.c
@@ -0,0 +1,268 @@
+/*
+ * panel driver for lvds and eDP panels
+ *
+ * Copyright (c) 2014 Samsung Electronics Co., Ltd
+ *
+ * Ajay Kumar <ajaykumar.rs at 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/consumer.h>
+#include <linux/module.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 gpio_desc *lcd_en_gpio;
+ struct gpio_desc *led_en_gpio;
+ struct videomode vm;
+ int width_mm;
+ int height_mm;
+ bool backlight_fet_enabled;
+ bool lcd_fet_enabled;
+ 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 (!lvds_panel->lcd_fet_enabled) {
+ if (regulator_enable(lvds_panel->lcd_fet)) {
+ DRM_ERROR("failed to enable LCD fet\n");
+ return -EAGAIN;
+ }
+ lvds_panel->lcd_fet_enabled = true;
+ }
+
+ if (lvds_panel->lcd_en_gpio)
+ gpiod_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 (!lvds_panel->backlight_fet_enabled) {
+ if (regulator_enable(lvds_panel->backlight_fet)) {
+ DRM_ERROR("failed to enable LED fet\n");
+ return -EAGAIN;
+ }
+ lvds_panel->backlight_fet_enabled = true;
+ }
+
+ msleep(lvds_panel->panel_enable_delay);
+
+ if (lvds_panel->led_en_gpio)
+ gpiod_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 (lvds_panel->led_en_gpio)
+ gpiod_set_value(lvds_panel->led_en_gpio, 0);
+
+ 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 (lvds_panel->lcd_en_gpio)
+ gpiod_set_value(lvds_panel->lcd_en_gpio, 0);
+
+ 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(dev, "lcd");
+ if (IS_ERR(panel->lcd_fet))
+ return -EPROBE_DEFER;
+
+ panel->backlight_fet = devm_regulator_get(dev, "backlight");
+ if (IS_ERR(panel->backlight_fet))
+ return -EPROBE_DEFER;
+
+ 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);
+
+ panel->lcd_en_gpio = devm_gpiod_get(dev, "lcd-enable");
+ if (IS_ERR(panel->lcd_en_gpio)) {
+ ret = PTR_ERR(panel->lcd_en_gpio);
+ if (ret != -ENOENT) {
+ dev_err(dev, "failed to request GPIO: %d\n", ret);
+ return ret;
+ }
+ panel->lcd_en_gpio = NULL;
+ } else {
+ ret = gpiod_direction_output(panel->lcd_en_gpio, 0);
+ if (ret < 0) {
+ dev_err(dev, "failed to setup GPIO: %d\n", ret);
+ return ret;
+ }
+ }
+
+ panel->led_en_gpio = devm_gpiod_get(dev, "backlight-enable");
+ if (IS_ERR(panel->led_en_gpio)) {
+ ret = PTR_ERR(panel->led_en_gpio);
+ if (ret != -ENOENT) {
+ dev_err(dev, "failed to request GPIO: %d\n", ret);
+ return ret;
+ }
+ panel->led_en_gpio = NULL;
+ } else {
+ ret = gpiod_direction_output(panel->led_en_gpio, 0);
+ if (ret < 0) {
+ dev_err(dev, "failed to setup GPIO: %d\n", ret);
+ return ret;
+ }
+ }
+
+ 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.rs at samsung.com>");
+MODULE_DESCRIPTION("lvds/eDP panel driver");
+MODULE_LICENSE("GPL v2");
--
1.7.9.5
