drm: panels: Add LVDS panel driver

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

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

/*

 * 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@ideasonboard.com)

 *

 * 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_LSB_TO_MSB

					  : DRM_BUS_FLAG_DATA_MSB_TO_LSB;

	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", },

	{ /* Sentinel */ },

};

MODULE_DEVICE_TABLE(of, panel_lvds_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@ideasonboard.com>");

MODULE_DESCRIPTION("LVDS Panel Driver");

MODULE_LICENSE("GPL");