drm/panel: Add driver for Seiko 43WVF1G panel

Add driver for Seiko Instruments Inc. 4.3" WVGA (800 x RGB x 480)
TFT with Touch-Panel.

Datasheet available at:
http://www.glyn.de/data/glyn/media/doc/43wvf1g-0.pdf

Seiko 43WVF1G panel has two power supplies: avdd and dvdd and they
require a specific power on/down sequence.
For this reason the simple panel driver cannot be used to drive this
panel, so create a new one heavily based on simple panel.

Based on initial patch submission from Breno Lima.
Signed-off-by: Marco Franchi <marco.franchi@nxp.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1500567179-6967-1-git-send-email-marco.franchi@nxp.com

Documentation/devicetree/bindings/display/panel/seiko,43wvf1g.txt

+Seiko Instruments Inc. 4.3" WVGA (800 x RGB x 480) TFT with Touch-Panel
+
+Required properties:
+- compatible: should be "sii,43wvf1g".
+- "dvdd-supply": 3v3 digital regulator.
+- "avdd-supply": 5v analog regulator.
+
+Optional properties:
+- backlight: phandle for the backlight control.
+
+Example:
+
+	panel {
+		compatible = "sii,43wvf1g";
+		backlight = <&backlight_display>;
+		dvdd-supply = <&reg_lcd_3v3>;
+		avdd-supply = <&reg_lcd_5v>;
+		port {
+			panel_in: endpoint {
+				remote-endpoint = <&display_out>;
+			};
+		};
+	};

drivers/gpu/drm/panel/Kconfig

@@ -102,6 +102,15 @@ config DRM_PANEL_SAMSUNG_S6E8AA0
 	select DRM_MIPI_DSI
 	select VIDEOMODE_HELPERS
 
+config DRM_PANEL_SEIKO_43WVF1G
+	tristate "Seiko 43WVF1G panel"
+	depends on OF
+	depends on BACKLIGHT_CLASS_DEVICE
+	select VIDEOMODE_HELPERS
+	help
+	  Say Y here if you want to enable support for the Seiko
+	  43WVF1G controller for 800x480 LCD panels
+
 config DRM_PANEL_SHARP_LQ101R1SX01
 	tristate "Sharp LQ101R1SX01 panel"
 	depends on OF

drivers/gpu/drm/panel/Makefile

@@ -9,6 +9,7 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E3HA2) += panel-samsung-s6e3ha2.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E63J0X03) += panel-samsung-s6e63j0x03.o
 obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
+obj-$(CONFIG_DRM_PANEL_SEIKO_43WVF1G) += panel-seiko-43wvf1g.o
 obj-$(CONFIG_DRM_PANEL_SHARP_LQ101R1SX01) += panel-sharp-lq101r1sx01.o
 obj-$(CONFIG_DRM_PANEL_SHARP_LS043T1LE01) += panel-sharp-ls043t1le01.o
 obj-$(CONFIG_DRM_PANEL_SITRONIX_ST7789V) += panel-sitronix-st7789v.o

drivers/gpu/drm/panel/panel-seiko-43wvf1g.c

+/*
+ * Copyright (C) 2017 NXP Semiconductors.
+ * Author: Marco Franchi <marco.franchi@nxp.com>
+ *
+ * Based on Panel Simple driver by Thierry Reding <treding@nvidia.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/backlight.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drmP.h>
+#include <drm/drm_crtc.h>
+#include <drm/drm_panel.h>
+
+#include <video/display_timing.h>
+#include <video/videomode.h>
+
+struct seiko_panel_desc {
+	const struct drm_display_mode *modes;
+	unsigned int num_modes;
+	const struct display_timing *timings;
+	unsigned int num_timings;
+
+	unsigned int bpc;
+
+	/**
+	 * @width: width (in millimeters) of the panel's active display area
+	 * @height: height (in millimeters) of the panel's active display area
+	 */
+	struct {
+		unsigned int width;
+		unsigned int height;
+	} size;
+
+	u32 bus_format;
+	u32 bus_flags;
+};
+
+struct seiko_panel {
+	struct drm_panel base;
+	bool prepared;
+	bool enabled;
+	const struct seiko_panel_desc *desc;
+	struct backlight_device *backlight;
+	struct regulator *dvdd;
+	struct regulator *avdd;
+};
+
+static inline struct seiko_panel *to_seiko_panel(struct drm_panel *panel)
+{
+	return container_of(panel, struct seiko_panel, base);
+}
+
+static int seiko_panel_get_fixed_modes(struct seiko_panel *panel)
+{
+	struct drm_connector *connector = panel->base.connector;
+	struct drm_device *drm = panel->base.drm;
+	struct drm_display_mode *mode;
+	unsigned int i, num = 0;
+
+	if (!panel->desc)
+		return 0;
+
+	for (i = 0; i < panel->desc->num_timings; i++) {
+		const struct display_timing *dt = &panel->desc->timings[i];
+		struct videomode vm;
+
+		videomode_from_timing(dt, &vm);
+		mode = drm_mode_create(drm);
+		if (!mode) {
+			dev_err(drm->dev, "failed to add mode %ux%u\n",
+				dt->hactive.typ, dt->vactive.typ);
+			continue;
+		}
+
+		drm_display_mode_from_videomode(&vm, mode);
+
+		mode->type |= DRM_MODE_TYPE_DRIVER;
+
+		if (panel->desc->num_timings == 1)
+			mode->type |= DRM_MODE_TYPE_PREFERRED;
+
+		drm_mode_probed_add(connector, mode);
+		num++;
+	}
+
+	for (i = 0; i < panel->desc->num_modes; i++) {
+		const struct drm_display_mode *m = &panel->desc->modes[i];
+
+		mode = drm_mode_duplicate(drm, m);
+		if (!mode) {
+			dev_err(drm->dev, "failed to add mode %ux%u@%u\n",
+				m->hdisplay, m->vdisplay, m->vrefresh);
+			continue;
+		}
+
+		mode->type |= DRM_MODE_TYPE_DRIVER;
+
+		if (panel->desc->num_modes == 1)
+			mode->type |= DRM_MODE_TYPE_PREFERRED;
+
+		drm_mode_set_name(mode);
+
+		drm_mode_probed_add(connector, mode);
+		num++;
+	}
+
+	connector->display_info.bpc = panel->desc->bpc;
+	connector->display_info.width_mm = panel->desc->size.width;
+	connector->display_info.height_mm = panel->desc->size.height;
+	if (panel->desc->bus_format)
+		drm_display_info_set_bus_formats(&connector->display_info,
+						 &panel->desc->bus_format, 1);
+	connector->display_info.bus_flags = panel->desc->bus_flags;
+
+	return num;
+}
+
+static int seiko_panel_disable(struct drm_panel *panel)
+{
+	struct seiko_panel *p = to_seiko_panel(panel);
+
+	if (!p->enabled)
+		return 0;
+
+	if (p->backlight) {
+		p->backlight->props.power = FB_BLANK_POWERDOWN;
+		p->backlight->props.state |= BL_CORE_FBBLANK;
+		backlight_update_status(p->backlight);
+	}
+
+	p->enabled = false;
+
+	return 0;
+}
+
+static int seiko_panel_unprepare(struct drm_panel *panel)
+{
+	struct seiko_panel *p = to_seiko_panel(panel);
+
+	if (!p->prepared)
+		return 0;
+
+	regulator_disable(p->avdd);
+
+	/* Add a 100ms delay as per the panel datasheet */
+	msleep(100);
+
+	regulator_disable(p->dvdd);
+
+	p->prepared = false;
+
+	return 0;
+}
+
+static int seiko_panel_prepare(struct drm_panel *panel)
+{
+	struct seiko_panel *p = to_seiko_panel(panel);
+	int err;
+
+	if (p->prepared)
+		return 0;
+
+	err = regulator_enable(p->dvdd);
+	if (err < 0) {
+		dev_err(panel->dev, "failed to enable dvdd: %d\n", err);
+		return err;
+	}
+
+	/* Add a 100ms delay as per the panel datasheet */
+	msleep(100);
+
+	err = regulator_enable(p->avdd);
+	if (err < 0) {
+		dev_err(panel->dev, "failed to enable avdd: %d\n", err);
+		goto disable_dvdd;
+	}
+
+	p->prepared = true;
+
+	return 0;
+
+disable_dvdd:
+	regulator_disable(p->dvdd);
+	return err;
+}
+
+static int seiko_panel_enable(struct drm_panel *panel)
+{
+	struct seiko_panel *p = to_seiko_panel(panel);
+
+	if (p->enabled)
+		return 0;
+
+	if (p->backlight) {
+		p->backlight->props.state &= ~BL_CORE_FBBLANK;
+		p->backlight->props.power = FB_BLANK_UNBLANK;
+		backlight_update_status(p->backlight);
+	}
+
+	p->enabled = true;
+
+	return 0;
+}
+
+static int seiko_panel_get_modes(struct drm_panel *panel)
+{
+	struct seiko_panel *p = to_seiko_panel(panel);
+
+	/* add hard-coded panel modes */
+	return seiko_panel_get_fixed_modes(p);
+}
+
+static int seiko_panel_get_timings(struct drm_panel *panel,
+				    unsigned int num_timings,
+				    struct display_timing *timings)
+{
+	struct seiko_panel *p = to_seiko_panel(panel);
+	unsigned int i;
+
+	if (p->desc->num_timings < num_timings)
+		num_timings = p->desc->num_timings;
+
+	if (timings)
+		for (i = 0; i < num_timings; i++)
+			timings[i] = p->desc->timings[i];
+
+	return p->desc->num_timings;
+}
+
+static const struct drm_panel_funcs seiko_panel_funcs = {
+	.disable = seiko_panel_disable,
+	.unprepare = seiko_panel_unprepare,
+	.prepare = seiko_panel_prepare,
+	.enable = seiko_panel_enable,
+	.get_modes = seiko_panel_get_modes,
+	.get_timings = seiko_panel_get_timings,
+};
+
+static int seiko_panel_probe(struct device *dev,
+					const struct seiko_panel_desc *desc)
+{
+	struct device_node *backlight;
+	struct seiko_panel *panel;
+	int err;
+
+	panel = devm_kzalloc(dev, sizeof(*panel), GFP_KERNEL);
+	if (!panel)
+		return -ENOMEM;
+
+	panel->enabled = false;
+	panel->prepared = false;
+	panel->desc = desc;
+
+	panel->dvdd = devm_regulator_get(dev, "dvdd");
+	if (IS_ERR(panel->dvdd))
+		return PTR_ERR(panel->dvdd);
+
+	panel->avdd = devm_regulator_get(dev, "avdd");
+	if (IS_ERR(panel->avdd))
+		return PTR_ERR(panel->avdd);
+
+	backlight = of_parse_phandle(dev->of_node, "backlight", 0);
+	if (backlight) {
+		panel->backlight = of_find_backlight_by_node(backlight);
+		of_node_put(backlight);
+
+		if (!panel->backlight)
+			return -EPROBE_DEFER;
+	}
+
+	drm_panel_init(&panel->base);
+	panel->base.dev = dev;
+	panel->base.funcs = &seiko_panel_funcs;
+
+	err = drm_panel_add(&panel->base);
+	if (err < 0)
+		return err;
+
+	dev_set_drvdata(dev, panel);
+
+	return 0;
+}
+
+static int seiko_panel_remove(struct platform_device *pdev)
+{
+	struct seiko_panel *panel = dev_get_drvdata(&pdev->dev);
+
+	drm_panel_detach(&panel->base);
+	drm_panel_remove(&panel->base);
+
+	seiko_panel_disable(&panel->base);
+
+	if (panel->backlight)
+		put_device(&panel->backlight->dev);
+
+	return 0;
+}
+
+static void seiko_panel_shutdown(struct platform_device *pdev)
+{
+	struct seiko_panel *panel = dev_get_drvdata(&pdev->dev);
+
+	seiko_panel_disable(&panel->base);
+}
+
+static const struct display_timing seiko_43wvf1g_timing = {
+	.pixelclock = { 33500000, 33500000, 33500000 },
+	.hactive = { 800, 800, 800 },
+	.hfront_porch = {  164, 164, 164 },
+	.hback_porch = { 89, 89, 89 },
+	.hsync_len = { 10, 10, 10 },
+	.vactive = { 480, 480, 480 },
+	.vfront_porch = { 10, 10, 10 },
+	.vback_porch = { 23, 23, 23 },
+	.vsync_len = { 10, 10, 10 },
+	.flags = DISPLAY_FLAGS_DE_LOW,
+};
+
+static const struct seiko_panel_desc seiko_43wvf1g = {
+	.timings = &seiko_43wvf1g_timing,
+	.num_timings = 1,
+	.bpc = 8,
+	.size = {
+		.width = 93,
+		.height = 57,
+	},
+	.bus_format = MEDIA_BUS_FMT_RGB888_1X24,
+	.bus_flags = DRM_BUS_FLAG_DE_HIGH | DRM_BUS_FLAG_PIXDATA_NEGEDGE,
+};
+
+static const struct of_device_id platform_of_match[] = {
+	{
+		.compatible = "sii,43wvf1g",
+		.data = &seiko_43wvf1g,
+	}, {
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, platform_of_match);
+
+static int seiko_panel_platform_probe(struct platform_device *pdev)
+{
+	const struct of_device_id *id;
+
+	id = of_match_node(platform_of_match, pdev->dev.of_node);
+	if (!id)
+		return -ENODEV;
+
+	return seiko_panel_probe(&pdev->dev, id->data);
+}
+
+static struct platform_driver seiko_panel_platform_driver = {
+	.driver = {
+		.name = "seiko_panel",
+		.of_match_table = platform_of_match,
+	},
+	.probe = seiko_panel_platform_probe,
+	.remove = seiko_panel_remove,
+	.shutdown = seiko_panel_shutdown,
+};
+module_platform_driver(seiko_panel_platform_driver);
+
+MODULE_AUTHOR("Marco Franchi <marco.franchi@nxp.com");
+MODULE_DESCRIPTION("Seiko 43WVF1G panel driver");
+MODULE_LICENSE("GPL v2");