drm/panel: Add Kingdisplay KD097D04 panel driver

Support Kingdisplay KD097D04 9.7" 1536x2048 TFT LCD panel, it is a MIPI
dual-DSI panel.

v4-resend:
- Thierry noted missing dt-bindings for v4 but forgot that he
  already had applied them one kernel release back in
  https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=ebc950fdff6d5f9250cd5a5a348af97f7d8508df
v4:
- address Philipp's comments
  - real range for usleep_range and
  - poweroff ordering in kingdisplay_panel_prepare
  - return value beautification in panel_probe
- update author naming for full name
v3:
- address Thierry's comments
  - error handling for init dsi writes in init
  - unconditionally remove the panel
  - don't use drm_panel_detach
  - a bit of variable signednes wiggling
- I did talk to ChromeOS people and the delays really should be as short
  as possible, so dropped the 100ms from the delay comments
v2:
- update timing + cmds from chromeos kernel
- new backlight API including switch to devm_of_find_backlight
- fix most of Sean Paul's comments
  enable/prepare tracking seems something all panels do
- document origins of the init sequence
- lanes per dsi interface to 4 (two interfaces). Matches how tegra
  and pending rockchip dual-dsi handle (dual-)dsi lanes
- spdx header instead of license boilerplate
Signed-off-by: Nickey Yang <nickey.yang@rock-chips.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Reviewed-by: Sean Paul <sean@poorly.run>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181030091528.28211-1-heiko@sntech.de

drivers/gpu/drm/panel/Kconfig

@@ -77,6 +77,17 @@ config DRM_PANEL_JDI_LT070ME05000
 	  The panel has a 1200(RGB)×1920 (WUXGA) resolution and uses
 	  24 bit per pixel.
 
+config DRM_PANEL_KINGDISPLAY_KD097D04
+	tristate "Kingdisplay kd097d04 panel"
+	depends on OF
+	depends on DRM_MIPI_DSI
+	depends on BACKLIGHT_CLASS_DEVICE
+	help
+	  Say Y here if you want to enable support for Kingdisplay kd097d04
+	  TFT-LCD modules. The panel has a 1536x2048 resolution and uses
+	  24 bit RGB per pixel. It provides a MIPI DSI interface to
+	  the host and has a built-in LED backlight.
+
 config DRM_PANEL_SAMSUNG_LD9040
 	tristate "Samsung LD9040 RGB/SPI panel"
 	depends on OF && SPI

drivers/gpu/drm/panel/Makefile

@@ -6,6 +6,7 @@ obj-$(CONFIG_DRM_PANEL_ILITEK_IL9322) += panel-ilitek-ili9322.o
 obj-$(CONFIG_DRM_PANEL_ILITEK_ILI9881C) += panel-ilitek-ili9881c.o
 obj-$(CONFIG_DRM_PANEL_INNOLUX_P079ZCA) += panel-innolux-p079zca.o
 obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
+obj-$(CONFIG_DRM_PANEL_KINGDISPLAY_KD097D04) += panel-kingdisplay-kd097d04.o
 obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
 obj-$(CONFIG_DRM_PANEL_OLIMEX_LCD_OLINUXINO) += panel-olimex-lcd-olinuxino.o
 obj-$(CONFIG_DRM_PANEL_ORISETECH_OTM8009A) += panel-orisetech-otm8009a.o

drivers/gpu/drm/panel/panel-kingdisplay-kd097d04.c

+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2017, Fuzhou Rockchip Electronics Co., Ltd
+ */
+
+#include <linux/backlight.h>
+#include <linux/gpio/consumer.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_mipi_dsi.h>
+#include <drm/drm_panel.h>
+
+#include <video/mipi_display.h>
+
+struct kingdisplay_panel {
+	struct drm_panel base;
+	struct mipi_dsi_device *link;
+
+	struct backlight_device *backlight;
+	struct regulator *supply;
+	struct gpio_desc *enable_gpio;
+
+	bool prepared;
+	bool enabled;
+};
+
+struct kingdisplay_panel_cmd {
+	char cmd;
+	char data;
+};
+
+/*
+ * According to the discussion on
+ * https://review.coreboot.org/#/c/coreboot/+/22472/
+ * the panel init array is not part of the panels datasheet but instead
+ * just came in this form from the panel vendor.
+ */
+static const struct kingdisplay_panel_cmd init_code[] = {
+	/* voltage setting */
+	{ 0xB0, 0x00 },
+	{ 0xB2, 0x02 },
+	{ 0xB3, 0x11 },
+	{ 0xB4, 0x00 },
+	{ 0xB6, 0x80 },
+	/* VCOM disable */
+	{ 0xB7, 0x02 },
+	{ 0xB8, 0x80 },
+	{ 0xBA, 0x43 },
+	/* VCOM setting */
+	{ 0xBB, 0x53 },
+	/* VSP setting */
+	{ 0xBC, 0x0A },
+	/* VSN setting */
+	{ 0xBD, 0x4A },
+	/* VGH setting */
+	{ 0xBE, 0x2F },
+	/* VGL setting */
+	{ 0xBF, 0x1A },
+	{ 0xF0, 0x39 },
+	{ 0xF1, 0x22 },
+	/* Gamma setting */
+	{ 0xB0, 0x02 },
+	{ 0xC0, 0x00 },
+	{ 0xC1, 0x01 },
+	{ 0xC2, 0x0B },
+	{ 0xC3, 0x15 },
+	{ 0xC4, 0x22 },
+	{ 0xC5, 0x11 },
+	{ 0xC6, 0x15 },
+	{ 0xC7, 0x19 },
+	{ 0xC8, 0x1A },
+	{ 0xC9, 0x16 },
+	{ 0xCA, 0x18 },
+	{ 0xCB, 0x13 },
+	{ 0xCC, 0x18 },
+	{ 0xCD, 0x13 },
+	{ 0xCE, 0x1C },
+	{ 0xCF, 0x19 },
+	{ 0xD0, 0x21 },
+	{ 0xD1, 0x2C },
+	{ 0xD2, 0x2F },
+	{ 0xD3, 0x30 },
+	{ 0xD4, 0x19 },
+	{ 0xD5, 0x1F },
+	{ 0xD6, 0x00 },
+	{ 0xD7, 0x01 },
+	{ 0xD8, 0x0B },
+	{ 0xD9, 0x15 },
+	{ 0xDA, 0x22 },
+	{ 0xDB, 0x11 },
+	{ 0xDC, 0x15 },
+	{ 0xDD, 0x19 },
+	{ 0xDE, 0x1A },
+	{ 0xDF, 0x16 },
+	{ 0xE0, 0x18 },
+	{ 0xE1, 0x13 },
+	{ 0xE2, 0x18 },
+	{ 0xE3, 0x13 },
+	{ 0xE4, 0x1C },
+	{ 0xE5, 0x19 },
+	{ 0xE6, 0x21 },
+	{ 0xE7, 0x2C },
+	{ 0xE8, 0x2F },
+	{ 0xE9, 0x30 },
+	{ 0xEA, 0x19 },
+	{ 0xEB, 0x1F },
+	/* GOA MUX setting */
+	{ 0xB0, 0x01 },
+	{ 0xC0, 0x10 },
+	{ 0xC1, 0x0F },
+	{ 0xC2, 0x0E },
+	{ 0xC3, 0x0D },
+	{ 0xC4, 0x0C },
+	{ 0xC5, 0x0B },
+	{ 0xC6, 0x0A },
+	{ 0xC7, 0x09 },
+	{ 0xC8, 0x08 },
+	{ 0xC9, 0x07 },
+	{ 0xCA, 0x06 },
+	{ 0xCB, 0x05 },
+	{ 0xCC, 0x00 },
+	{ 0xCD, 0x01 },
+	{ 0xCE, 0x02 },
+	{ 0xCF, 0x03 },
+	{ 0xD0, 0x04 },
+	{ 0xD6, 0x10 },
+	{ 0xD7, 0x0F },
+	{ 0xD8, 0x0E },
+	{ 0xD9, 0x0D },
+	{ 0xDA, 0x0C },
+	{ 0xDB, 0x0B },
+	{ 0xDC, 0x0A },
+	{ 0xDD, 0x09 },
+	{ 0xDE, 0x08 },
+	{ 0xDF, 0x07 },
+	{ 0xE0, 0x06 },
+	{ 0xE1, 0x05 },
+	{ 0xE2, 0x00 },
+	{ 0xE3, 0x01 },
+	{ 0xE4, 0x02 },
+	{ 0xE5, 0x03 },
+	{ 0xE6, 0x04 },
+	{ 0xE7, 0x00 },
+	{ 0xEC, 0xC0 },
+	/* GOA timing setting */
+	{ 0xB0, 0x03 },
+	{ 0xC0, 0x01 },
+	{ 0xC2, 0x6F },
+	{ 0xC3, 0x6F },
+	{ 0xC5, 0x36 },
+	{ 0xC8, 0x08 },
+	{ 0xC9, 0x04 },
+	{ 0xCA, 0x41 },
+	{ 0xCC, 0x43 },
+	{ 0xCF, 0x60 },
+	{ 0xD2, 0x04 },
+	{ 0xD3, 0x04 },
+	{ 0xD4, 0x03 },
+	{ 0xD5, 0x02 },
+	{ 0xD6, 0x01 },
+	{ 0xD7, 0x00 },
+	{ 0xDB, 0x01 },
+	{ 0xDE, 0x36 },
+	{ 0xE6, 0x6F },
+	{ 0xE7, 0x6F },
+	/* GOE setting */
+	{ 0xB0, 0x06 },
+	{ 0xB8, 0xA5 },
+	{ 0xC0, 0xA5 },
+	{ 0xD5, 0x3F },
+};
+
+static inline
+struct kingdisplay_panel *to_kingdisplay_panel(struct drm_panel *panel)
+{
+	return container_of(panel, struct kingdisplay_panel, base);
+}
+
+static int kingdisplay_panel_disable(struct drm_panel *panel)
+{
+	struct kingdisplay_panel *kingdisplay = to_kingdisplay_panel(panel);
+	int err;
+
+	if (!kingdisplay->enabled)
+		return 0;
+
+	backlight_disable(kingdisplay->backlight);
+
+	err = mipi_dsi_dcs_set_display_off(kingdisplay->link);
+	if (err < 0)
+		DRM_DEV_ERROR(panel->dev, "failed to set display off: %d\n",
+			      err);
+
+	kingdisplay->enabled = false;
+
+	return 0;
+}
+
+static int kingdisplay_panel_unprepare(struct drm_panel *panel)
+{
+	struct kingdisplay_panel *kingdisplay = to_kingdisplay_panel(panel);
+	int err;
+
+	if (!kingdisplay->prepared)
+		return 0;
+
+	err = mipi_dsi_dcs_enter_sleep_mode(kingdisplay->link);
+	if (err < 0) {
+		DRM_DEV_ERROR(panel->dev, "failed to enter sleep mode: %d\n",
+			      err);
+		return err;
+	}
+
+	/* T15: 120ms */
+	msleep(120);
+
+	gpiod_set_value_cansleep(kingdisplay->enable_gpio, 0);
+
+	err = regulator_disable(kingdisplay->supply);
+	if (err < 0)
+		return err;
+
+	kingdisplay->prepared = false;
+
+	return 0;
+}
+
+static int kingdisplay_panel_prepare(struct drm_panel *panel)
+{
+	struct kingdisplay_panel *kingdisplay = to_kingdisplay_panel(panel);
+	int err, regulator_err;
+	unsigned int i;
+
+	if (kingdisplay->prepared)
+		return 0;
+
+	gpiod_set_value_cansleep(kingdisplay->enable_gpio, 0);
+
+	err = regulator_enable(kingdisplay->supply);
+	if (err < 0)
+		return err;
+
+	/* T2: 15ms */
+	usleep_range(15000, 16000);
+
+	gpiod_set_value_cansleep(kingdisplay->enable_gpio, 1);
+
+	/* T4: 15ms */
+	usleep_range(15000, 16000);
+
+	for (i = 0; i < ARRAY_SIZE(init_code); i++) {
+		err = mipi_dsi_generic_write(kingdisplay->link, &init_code[i],
+					sizeof(struct kingdisplay_panel_cmd));
+		if (err < 0) {
+			DRM_DEV_ERROR(panel->dev, "failed write init cmds: %d\n",
+				      err);
+			goto poweroff;
+		}
+	}
+
+	err = mipi_dsi_dcs_exit_sleep_mode(kingdisplay->link);
+	if (err < 0) {
+		DRM_DEV_ERROR(panel->dev, "failed to exit sleep mode: %d\n",
+			      err);
+		goto poweroff;
+	}
+
+	/* T6: 120ms */
+	msleep(120);
+
+	err = mipi_dsi_dcs_set_display_on(kingdisplay->link);
+	if (err < 0) {
+		DRM_DEV_ERROR(panel->dev, "failed to set display on: %d\n",
+			      err);
+		goto poweroff;
+	}
+
+	/* T7: 10ms */
+	usleep_range(10000, 11000);
+
+	kingdisplay->prepared = true;
+
+	return 0;
+
+poweroff:
+	gpiod_set_value_cansleep(kingdisplay->enable_gpio, 0);
+
+	regulator_err = regulator_disable(kingdisplay->supply);
+	if (regulator_err)
+		DRM_DEV_ERROR(panel->dev, "failed to disable regulator: %d\n",
+			      regulator_err);
+
+	return err;
+}
+
+static int kingdisplay_panel_enable(struct drm_panel *panel)
+{
+	struct kingdisplay_panel *kingdisplay = to_kingdisplay_panel(panel);
+	int ret;
+
+	if (kingdisplay->enabled)
+		return 0;
+
+	ret = backlight_enable(kingdisplay->backlight);
+	if (ret) {
+		DRM_DEV_ERROR(panel->drm->dev,
+			      "Failed to enable backlight %d\n", ret);
+		return ret;
+	}
+
+	kingdisplay->enabled = true;
+
+	return 0;
+}
+
+static const struct drm_display_mode default_mode = {
+	.clock = 229000,
+	.hdisplay = 1536,
+	.hsync_start = 1536 + 100,
+	.hsync_end = 1536 + 100 + 24,
+	.htotal = 1536 + 100 + 24 + 100,
+	.vdisplay = 2048,
+	.vsync_start = 2048 + 95,
+	.vsync_end = 2048 + 95 + 2,
+	.vtotal = 2048 + 95 + 2 + 23,
+	.vrefresh = 60,
+};
+
+static int kingdisplay_panel_get_modes(struct drm_panel *panel)
+{
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(panel->drm, &default_mode);
+	if (!mode) {
+		DRM_DEV_ERROR(panel->drm->dev, "failed to add mode %ux%ux@%u\n",
+			      default_mode.hdisplay, default_mode.vdisplay,
+			      default_mode.vrefresh);
+		return -ENOMEM;
+	}
+
+	drm_mode_set_name(mode);
+
+	drm_mode_probed_add(panel->connector, mode);
+
+	panel->connector->display_info.width_mm = 147;
+	panel->connector->display_info.height_mm = 196;
+	panel->connector->display_info.bpc = 8;
+
+	return 1;
+}
+
+static const struct drm_panel_funcs kingdisplay_panel_funcs = {
+	.disable = kingdisplay_panel_disable,
+	.unprepare = kingdisplay_panel_unprepare,
+	.prepare = kingdisplay_panel_prepare,
+	.enable = kingdisplay_panel_enable,
+	.get_modes = kingdisplay_panel_get_modes,
+};
+
+static const struct of_device_id kingdisplay_of_match[] = {
+	{ .compatible = "kingdisplay,kd097d04", },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, kingdisplay_of_match);
+
+static int kingdisplay_panel_add(struct kingdisplay_panel *kingdisplay)
+{
+	struct device *dev = &kingdisplay->link->dev;
+	int err;
+
+	kingdisplay->supply = devm_regulator_get(dev, "power");
+	if (IS_ERR(kingdisplay->supply))
+		return PTR_ERR(kingdisplay->supply);
+
+	kingdisplay->enable_gpio = devm_gpiod_get_optional(dev, "enable",
+							   GPIOD_OUT_HIGH);
+	if (IS_ERR(kingdisplay->enable_gpio)) {
+		err = PTR_ERR(kingdisplay->enable_gpio);
+		dev_dbg(dev, "failed to get enable gpio: %d\n", err);
+		kingdisplay->enable_gpio = NULL;
+	}
+
+	kingdisplay->backlight = devm_of_find_backlight(dev);
+	if (IS_ERR(kingdisplay->backlight))
+		return PTR_ERR(kingdisplay->backlight);
+
+	drm_panel_init(&kingdisplay->base);
+	kingdisplay->base.funcs = &kingdisplay_panel_funcs;
+	kingdisplay->base.dev = &kingdisplay->link->dev;
+
+	return drm_panel_add(&kingdisplay->base);
+}
+
+static void kingdisplay_panel_del(struct kingdisplay_panel *kingdisplay)
+{
+	drm_panel_remove(&kingdisplay->base);
+}
+
+static int kingdisplay_panel_probe(struct mipi_dsi_device *dsi)
+{
+	struct kingdisplay_panel *kingdisplay;
+	int err;
+
+	dsi->lanes = 4;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_BURST |
+			  MIPI_DSI_MODE_LPM;
+
+	kingdisplay = devm_kzalloc(&dsi->dev, sizeof(*kingdisplay), GFP_KERNEL);
+	if (!kingdisplay)
+		return -ENOMEM;
+
+	mipi_dsi_set_drvdata(dsi, kingdisplay);
+	kingdisplay->link = dsi;
+
+	err = kingdisplay_panel_add(kingdisplay);
+	if (err < 0)
+		return err;
+
+	return mipi_dsi_attach(dsi);
+}
+
+static int kingdisplay_panel_remove(struct mipi_dsi_device *dsi)
+{
+	struct kingdisplay_panel *kingdisplay = mipi_dsi_get_drvdata(dsi);
+	int err;
+
+	err = kingdisplay_panel_unprepare(&kingdisplay->base);
+	if (err < 0)
+		DRM_DEV_ERROR(&dsi->dev, "failed to unprepare panel: %d\n",
+			      err);
+
+	err = kingdisplay_panel_disable(&kingdisplay->base);
+	if (err < 0)
+		DRM_DEV_ERROR(&dsi->dev, "failed to disable panel: %d\n", err);
+
+	err = mipi_dsi_detach(dsi);
+	if (err < 0)
+		DRM_DEV_ERROR(&dsi->dev, "failed to detach from DSI host: %d\n",
+			      err);
+
+	kingdisplay_panel_del(kingdisplay);
+
+	return 0;
+}
+
+static void kingdisplay_panel_shutdown(struct mipi_dsi_device *dsi)
+{
+	struct kingdisplay_panel *kingdisplay = mipi_dsi_get_drvdata(dsi);
+
+	kingdisplay_panel_unprepare(&kingdisplay->base);
+	kingdisplay_panel_disable(&kingdisplay->base);
+}
+
+static struct mipi_dsi_driver kingdisplay_panel_driver = {
+	.driver = {
+		.name = "panel-kingdisplay-kd097d04",
+		.of_match_table = kingdisplay_of_match,
+	},
+	.probe = kingdisplay_panel_probe,
+	.remove = kingdisplay_panel_remove,
+	.shutdown = kingdisplay_panel_shutdown,
+};
+module_mipi_dsi_driver(kingdisplay_panel_driver);
+
+MODULE_AUTHOR("Chris Zhong <zyw@rock-chips.com>");
+MODULE_AUTHOR("Nickey Yang <nickey.yang@rock-chips.com>");
+MODULE_DESCRIPTION("kingdisplay KD097D04 panel driver");
+MODULE_LICENSE("GPL v2");