This driver supports LVDS panels that don't require device-specific
handling of power supplies or control signals. It implements automatic
backlight handling if the panel is attached to a backlight controller.
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@xxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/panel/Kconfig | 10 ++
drivers/gpu/drm/panel/Makefile | 1 +
drivers/gpu/drm/panel/panel-lvds.c | 284 +++++++++++++++++++++++++++++++++++++
3 files changed, 295 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 62aba976e744..5dc2106da2bc 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -7,6 +7,16 @@ config DRM_PANEL
menu "Display Panels"
depends on DRM && DRM_PANEL
+config DRM_PANEL_LVDS
+ tristate "Generic LVDS panel driver"
+ depends on OF
+ depends on BACKLIGHT_CLASS_DEVICE
+ select VIDEOMODE_HELPERS
+ help
+ This driver supports LVDS panels that don't require device-specific
+ handling of power supplies or control signals. It implements automatic
+ backlight handling if the panel is attached to a backlight controller.
+
config DRM_PANEL_SIMPLE
tristate "support for simple panels"
depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index a5c7ec0236e0..20b5060d1f47 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -1,3 +1,4 @@
+obj-$(CONFIG_DRM_PANEL_LVDS) += panel-lvds.o
obj-$(CONFIG_DRM_PANEL_SIMPLE) += panel-simple.o
obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
diff --git a/drivers/gpu/drm/panel/panel-lvds.c b/drivers/gpu/drm/panel/panel-lvds.c
new file mode 100644
index 000000000000..0a563a287abe
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-lvds.c
@@ -0,0 +1,284 @@
+/*
+ * rcar_du_crtc.c -- R-Car Display Unit CRTCs
+ *
+ * Copyright (C) 2016 Laurent Pinchart
+ * Copyright (C) 2016 Renesas Electronics Corporation
+ *
+ * Contact: Laurent Pinchart (laurent.pinchart@xxxxxxxxxxxxxxxx)
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ */
+
+#include <linux/backlight.h>
+#include <linux/gpio/consumer.h>
+#include <linux/module.h>
+#include <linux/of_platform.h>
+#include <linux/platform_device.h>
+#include <linux/slab.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_panel.h>
+
+#include <video/display_timing.h>
+#include <video/of_display_timing.h>
+#include <video/videomode.h>
+
+struct panel_lvds {
+ struct drm_panel panel;
+ struct device *dev;
+
+ const char *label;
+ unsigned int width;
+ unsigned int height;
+ struct videomode video_mode;
+ unsigned int bus_format;
+ bool data_mirror;
+
+ struct backlight_device *backlight;
+
+ struct gpio_desc *enable_gpio;
+ struct gpio_desc *reset_gpio;
+};
+
+static inline struct panel_lvds *to_panel_lvds(struct drm_panel *panel)
+{
+ return container_of(panel, struct panel_lvds, panel);
+}
+
+static int panel_lvds_disable(struct drm_panel *panel)
+{
+ struct panel_lvds *lvds = to_panel_lvds(panel);
+
+ if (lvds->backlight) {
+ lvds->backlight->props.power = FB_BLANK_POWERDOWN;
+ lvds->backlight->props.state |= BL_CORE_FBBLANK;
+ backlight_update_status(lvds->backlight);
+ }
+
+ return 0;
+}
+
+static int panel_lvds_unprepare(struct drm_panel *panel)
+{
+ struct panel_lvds *lvds = to_panel_lvds(panel);
+
+ if (lvds->enable_gpio)
+ gpiod_set_value_cansleep(lvds->enable_gpio, 0);
+
+ return 0;
+}
+
+static int panel_lvds_prepare(struct drm_panel *panel)
+{
+ struct panel_lvds *lvds = to_panel_lvds(panel);
+
+ if (lvds->enable_gpio)
+ gpiod_set_value_cansleep(lvds->enable_gpio, 1);
+
+ return 0;
+}
+
+static int panel_lvds_enable(struct drm_panel *panel)
+{
+ struct panel_lvds *lvds = to_panel_lvds(panel);
+
+ if (lvds->backlight) {
+ lvds->backlight->props.state &= ~BL_CORE_FBBLANK;
+ lvds->backlight->props.power = FB_BLANK_UNBLANK;
+ backlight_update_status(lvds->backlight);
+ }
+
+ return 0;
+}
+
+static int panel_lvds_get_modes(struct drm_panel *panel)
+{
+ struct panel_lvds *lvds = to_panel_lvds(panel);
+ struct drm_connector *connector = lvds->panel.connector;
+ struct drm_display_mode *mode;
+
+ mode = drm_mode_create(lvds->panel.drm);
+ if (!mode)
+ return 0;
+
+ drm_display_mode_from_videomode(&lvds->video_mode, mode);
+ mode->type |= DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED;
+ drm_mode_probed_add(connector, mode);
+
+ connector->display_info.width_mm = lvds->width;
+ connector->display_info.height_mm = lvds->height;
+ drm_display_info_set_bus_formats(&connector->display_info,
+ &lvds->bus_format, 1);
+ connector->display_info.bus_flags = lvds->data_mirror
+ ? DRM_BUS_FLAG_DATA_MIRROR : 0;
+
+ return 1;
+}
+
+static const struct drm_panel_funcs panel_lvds_funcs = {
+ .disable = panel_lvds_disable,
+ .unprepare = panel_lvds_unprepare,
+ .prepare = panel_lvds_prepare,
+ .enable = panel_lvds_enable,
+ .get_modes = panel_lvds_get_modes,
+};
+
+static int panel_lvds_parse_dt(struct panel_lvds *lvds)
+{
+ struct device_node *np = lvds->dev->of_node;
+ struct display_timing timing;
+ const char *mapping;
+ int ret;
+
+ ret = of_get_display_timing(np, "panel-timing", &timing);
+ if (ret < 0)
+ return ret;
+
+ videomode_from_timing(&timing, &lvds->video_mode);
+
+ ret = of_property_read_u32(np, "width-mm", &lvds->width);
+ if (ret < 0) {
+ dev_err(lvds->dev, "%s: invalid or missing %s DT property\n",
+ of_node_full_name(np), "width-mm");
+ return -ENODEV;
+ }
+ ret = of_property_read_u32(np, "height-mm", &lvds->height);
+ if (ret < 0) {
+ dev_err(lvds->dev, "%s: invalid or missing %s DT property\n",
+ of_node_full_name(np), "height-mm");
+ return -ENODEV;
+ }
+
+ of_property_read_string(np, "label", &lvds->label);
+
+ ret = of_property_read_string(np, "data-mapping", &mapping);
+ if (ret < 0) {
+ dev_err(lvds->dev, "%s: invalid or missing %s DT property\n",
+ of_node_full_name(np), "data-mapping");
+ return -ENODEV;
+ }
+
+ if (!strcmp(mapping, "jeida-18")) {
+ lvds->bus_format = MEDIA_BUS_FMT_RGB666_1X7X3_SPWG;
+ } else if (!strcmp(mapping, "jeida-24")) {
+ lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_JEIDA;
+ } else if (!strcmp(mapping, "vesa-24")) {
+ lvds->bus_format = MEDIA_BUS_FMT_RGB888_1X7X4_SPWG;
+ } else {
+ dev_err(lvds->dev, "%s: invalid or missing %s DT property\n",
+ of_node_full_name(np), "data-mapping");
+ return -EINVAL;
+ }
+
+ lvds->data_mirror = of_property_read_bool(np, "data-mirror");
+
+ return 0;
+}
+
+static int panel_lvds_probe(struct platform_device *pdev)
+{
+ struct panel_lvds *lvds;
+ struct device_node *np;
+ int ret;
+
+ lvds = devm_kzalloc(&pdev->dev, sizeof(*lvds), GFP_KERNEL);
+ if (!lvds)
+ return -ENOMEM;
+
+ lvds->dev = &pdev->dev;
+
+ ret = panel_lvds_parse_dt(lvds);
+ if (ret < 0)
+ return ret;
+
+ /* Get GPIOs and backlight controller. */
+ lvds->enable_gpio = devm_gpiod_get_optional(lvds->dev, "enable",
+ GPIOD_OUT_LOW);
+ if (IS_ERR(lvds->enable_gpio)) {
+ ret = PTR_ERR(lvds->enable_gpio);
+ dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
+ "enable", ret);
+ return ret;
+ }
+
+ lvds->reset_gpio = devm_gpiod_get_optional(lvds->dev, "reset",
+ GPIOD_OUT_HIGH);
+ if (IS_ERR(lvds->reset_gpio)) {
+ ret = PTR_ERR(lvds->reset_gpio);
+ dev_err(lvds->dev, "failed to request %s GPIO: %d\n",
+ "reset", ret);
+ return ret;
+ }
+
+ np = of_parse_phandle(lvds->dev->of_node, "backlight", 0);
+ if (np) {
+ lvds->backlight = of_find_backlight_by_node(np);
+ of_node_put(np);
+
+ if (!lvds->backlight)
+ return -EPROBE_DEFER;
+ }
+
+ /*
+ * TODO: Handle all power supplies specified in the DT node in a generic
+ * way for panels that don't care about power supply ordering. LVDS
+ * panels that require a specific power sequence will need a dedicated
+ * driver.
+ */
+
+ /* Register the panel. */
+ drm_panel_init(&lvds->panel);
+ lvds->panel.dev = lvds->dev;
+ lvds->panel.funcs = &panel_lvds_funcs;
+
+ ret = drm_panel_add(&lvds->panel);
+ if (ret < 0)
+ goto error;
+
+ dev_set_drvdata(lvds->dev, lvds);
+ return 0;
+
+error:
+ put_device(&lvds->backlight->dev);
+ return ret;
+}
+
+static int panel_lvds_remove(struct platform_device *pdev)
+{
+ struct panel_lvds *lvds = dev_get_drvdata(&pdev->dev);
+
+ drm_panel_detach(&lvds->panel);
+ drm_panel_remove(&lvds->panel);
+
+ panel_lvds_disable(&lvds->panel);
+
+ if (lvds->backlight)
+ put_device(&lvds->backlight->dev);
+
+ return 0;
+}
+
+static const struct of_device_id panel_lvds_of_table[] = {
+ { .compatible = "panel-lvds", },
+};
+
+MODULE_DEVICE_TABLE(of, rcar_du_of_table);
+
+static struct platform_driver panel_lvds_driver = {
+ .probe = panel_lvds_probe,
+ .remove = panel_lvds_remove,
+ .driver = {
+ .name = "panel-lvds",
+ .of_match_table = panel_lvds_of_table,
+ },
+};
+
+module_platform_driver(panel_lvds_driver);
+
+MODULE_AUTHOR("Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>");
+MODULE_DESCRIPTION("LVDS Panel Driver");
+MODULE_LICENSE("GPL");
--
Regards,
Laurent Pinchart
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