drm: panel: Add lg sw43408 panel driver

LG SW43408 is 1080x2160, 4-lane MIPI-DSI panel, used in some Pixel3
phones.

--
updated for changes in 5.10 - drm_panel_add() and drm_panel_detach() changes
updated for new lab name
updated for removal of vrefresh in 5.9-rc

Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
Change-Id: I19e34e6354a38432881fa673aced39bf35e2fc46

4 files changed, 761 insertions, 0 deletions

diff --git a/MAINTAINERS b/MAINTAINERS
index 992fe3b0900a..e3ff8cfd49af 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -5578,6 +5578,13 @@ S:	Orphan / Obsolete
 F:	drivers/gpu/drm/i810/
 F:	include/uapi/drm/i810_drm.h
 
+DRM DRIVER FOR LG SW43408 PANELS
+M:      Sumit Semwal <sumit.semwal@linaro.org>
+T:      git git://anongit.freedesktop.org/drm/drm-misc
+S:      Maintained
+F:      drivers/gpu/drm/panel/panel-lg-sw43408.c
+F:      Documentation/devicetree/bindings/display/panel/lg,sw43408-panel.txt
+
 DRM DRIVER FOR LVDS PANELS
 M:	Laurent Pinchart <laurent.pinchart@ideasonboard.com>
 L:	dri-devel@lists.freedesktop.org
diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index b4e021ea30f9..d0e0431ac525 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -178,6 +178,17 @@ config DRM_PANEL_LEADTEK_LTK500HD1829
 	  24 bit RGB per pixel. It provides a MIPI DSI interface to
 	  the host and has a built-in LED backlight.
 
+config DRM_PANEL_LG_SW43408
+	tristate "LG SW43408 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 LG sw43408 panel.
+	  The panel has a 1080x2160 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
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index ebbf488c7eac..f0e171d4d453 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -18,6 +18,7 @@ obj-$(CONFIG_DRM_PANEL_LEADTEK_LTK050H3146W) += panel-leadtek-ltk050h3146w.o
 obj-$(CONFIG_DRM_PANEL_LEADTEK_LTK500HD1829) += panel-leadtek-ltk500hd1829.o
 obj-$(CONFIG_DRM_PANEL_LG_LB035Q02) += panel-lg-lb035q02.o
 obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o
+obj-$(CONFIG_DRM_PANEL_LG_SW43408) += panel-lg-sw43408.o
 obj-$(CONFIG_DRM_PANEL_NEC_NL8048HL11) += panel-nec-nl8048hl11.o
 obj-$(CONFIG_DRM_PANEL_NOVATEK_NT35510) += panel-novatek-nt35510.o
 obj-$(CONFIG_DRM_PANEL_NOVATEK_NT36672A) += panel-novatek-nt36672a.o
diff --git a/drivers/gpu/drm/panel/panel-lg-sw43408.c b/drivers/gpu/drm/panel/panel-lg-sw43408.c
new file mode 100644
index 000000000000..dd8d0fa5b757
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-lg-sw43408.c
@@ -0,0 +1,742 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2019 Linaro Ltd
+ * Author: Sumit Semwal <sumit.semwal@linaro.org>
+ */
+
+#include <linux/backlight.h>
+#include <linux/delay.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/of_device.h>
+
+#include <linux/gpio/consumer.h>
+#include <linux/pinctrl/consumer.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_device.h>
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_print.h>
+
+#include <video/mipi_display.h>
+
+struct panel_cmd {
+	size_t len;
+	const char *data;
+};
+
+#define _INIT_CMD(...) { \
+	.len = sizeof((char[]){__VA_ARGS__}), \
+	.data = (char[]){__VA_ARGS__} }
+
+static const char * const regulator_names[] = {
+	"vddi",
+	"vpnl",
+	"lab",
+};
+
+static unsigned long const regulator_enable_loads[] = {
+	62000,
+	857000,
+	100000,
+};
+
+static unsigned long const regulator_disable_loads[] = {
+	80,
+	0,
+	100,
+};
+
+struct panel_desc {
+	const struct drm_display_mode *display_mode;
+	const char *panel_name;
+
+	unsigned int width_mm;
+	unsigned int height_mm;
+
+	unsigned long mode_flags;
+	enum mipi_dsi_pixel_format format;
+	unsigned int lanes;
+
+	const struct panel_cmd *on_cmds_1;
+	const struct panel_cmd *on_cmds_2;
+};
+
+struct panel_info {
+	struct drm_panel base;
+	struct mipi_dsi_device *link;
+	const struct panel_desc *desc;
+
+	struct backlight_device *backlight;
+	u32 brightness;
+	u32 max_brightness;
+
+	u32 init_delay_us;
+
+	struct regulator_bulk_data supplies[ARRAY_SIZE(regulator_names)];
+
+	struct gpio_desc *reset_gpio;
+
+	struct pinctrl *pinctrl;
+	struct pinctrl_state *active;
+	struct pinctrl_state *suspend;
+
+	bool prepared;
+	bool enabled;
+	bool first_enable;
+};
+
+static inline struct panel_info *to_panel_info(struct drm_panel *panel)
+{
+	return container_of(panel, struct panel_info, base);
+}
+
+
+/*
+ * Need to reset gpios and regulators once in the beginning,
+ */
+static int panel_reset_at_beginning(struct panel_info * pinfo)
+{
+	int ret = 0, i;
+
+	DRM_DEV_ERROR(pinfo->base.dev,
+					"panel_reset_at_beginning\n");
+	/* enable supplies */
+	for (i = 0; i < ARRAY_SIZE(pinfo->supplies); i++) {
+		ret = regulator_set_load(pinfo->supplies[i].consumer,
+					regulator_enable_loads[i]);
+		if (ret)
+			return ret;
+	}
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(pinfo->supplies), pinfo->supplies);
+	if (ret < 0)
+		return ret;
+
+	/* Disable supplies */
+	for (i = 0; i < ARRAY_SIZE(pinfo->supplies); i++) {
+		ret = regulator_set_load(pinfo->supplies[i].consumer,
+				regulator_disable_loads[i]);
+		if (ret) {
+			DRM_DEV_ERROR(pinfo->base.dev,
+				"regulator_set_load failed %d\n", ret);
+			return ret;
+		}
+	}
+
+	ret = regulator_bulk_disable(ARRAY_SIZE(pinfo->supplies), pinfo->supplies);
+	if (ret < 0)
+		return ret;
+
+	/*
+	 * Reset sequence of LG sw43408 panel requires the panel to be
+	 * out of reset for 9ms, followed by being held in reset
+	 * for 1ms and then out again
+	 */
+	gpiod_set_value(pinfo->reset_gpio, 1);
+	usleep_range(9000, 10000);
+	gpiod_set_value(pinfo->reset_gpio, 0);
+	usleep_range(1000, 2000);
+	gpiod_set_value(pinfo->reset_gpio, 1);
+	usleep_range(9000, 10000);
+
+	return 0;
+}
+
+static int send_mipi_cmds(struct drm_panel *panel, const struct panel_cmd *cmds)
+{
+	struct panel_info *pinfo = to_panel_info(panel);
+	unsigned int i = 0;
+	int err;
+
+	if (!cmds)
+		return -EFAULT;
+
+	for (i = 0; cmds[i].len != 0; i++) {
+		const struct panel_cmd *cmd = &cmds[i];
+
+		if (cmd->len == 2)
+			err = mipi_dsi_dcs_write(pinfo->link,
+						    cmd->data[1], NULL, 0);
+		else
+			err = mipi_dsi_dcs_write(pinfo->link,
+						    cmd->data[1], cmd->data + 2,
+						    cmd->len - 2);
+
+		if (err < 0)
+			return err;
+
+		usleep_range((cmd->data[0]) * 1000,
+			    (1 + cmd->data[0]) * 1000);
+	}
+
+	return 0;
+}
+
+static int panel_set_pinctrl_state(struct panel_info *panel, bool enable)
+{
+	int rc = 0;
+	struct pinctrl_state *state;
+
+	if (enable)
+		state = panel->active;
+	else
+		state = panel->suspend;
+
+	rc = pinctrl_select_state(panel->pinctrl, state);
+	if (rc)
+		pr_err("[%s] failed to set pin state, rc=%d\n", panel->desc->panel_name,
+			rc);
+	return rc;
+}
+
+static int lg_panel_disable(struct drm_panel *panel)
+{
+/* HACK: return 0 for now */
+
+#if 0
+	struct panel_info *pinfo = to_panel_info(panel);
+
+	backlight_disable(pinfo->backlight);
+
+	pinfo->enabled = false;
+#endif
+	return 0;
+}
+
+static int lg_panel_power_off(struct drm_panel *panel)
+{
+	struct panel_info *pinfo = to_panel_info(panel);
+	int i, ret = 0;
+pr_err("In sw43408 panel_power_off\n");
+	gpiod_set_value(pinfo->reset_gpio, 0);
+
+        ret = panel_set_pinctrl_state(pinfo, false);
+        if (ret) {
+                pr_err("[%s] failed to set pinctrl, rc=%d\n", pinfo->desc->panel_name, ret);
+		return ret;
+        }
+
+	for (i = 0; i < ARRAY_SIZE(pinfo->supplies); i++) {
+		ret = regulator_set_load(pinfo->supplies[i].consumer,
+				regulator_disable_loads[i]);
+		if (ret) {
+			DRM_DEV_ERROR(panel->dev,
+				"regulator_set_load failed %d\n", ret);
+			return ret;
+		}
+	}
+
+	ret = regulator_bulk_disable(ARRAY_SIZE(pinfo->supplies), pinfo->supplies);
+	if (ret) {
+		DRM_DEV_ERROR(panel->dev,
+			"regulator_bulk_disable failed %d\n", ret);
+	}
+	return ret;
+}
+
+static int lg_panel_unprepare(struct drm_panel *panel)
+{
+pr_err("In sw43408 panel_unprepare\n");
+/* HACK : Currently, after a suspend, the resume doesn't enable screen, so
+ *        don't disable the panel until we figure out why that is.
+ */
+return 0;
+
+#if 0
+	struct panel_info *pinfo = to_panel_info(panel);
+	int ret;
+
+	if (!pinfo->prepared)
+		return 0;
+
+	ret = mipi_dsi_dcs_set_display_off(pinfo->link);
+	if (ret < 0) {
+		DRM_DEV_ERROR(panel->dev,
+			"set_display_off cmd failed ret = %d\n",
+			ret);
+	}
+
+	/* 120ms delay required here as per DCS spec */
+	msleep(120);
+
+	ret = mipi_dsi_dcs_enter_sleep_mode(pinfo->link);
+	if (ret < 0) {
+		DRM_DEV_ERROR(panel->dev,
+			"enter_sleep cmd failed ret = %d\n", ret);
+	}
+	/* 0x64 = 100ms delay */
+	msleep(100);
+
+	ret = lg_panel_power_off(panel);
+	if (ret < 0)
+		DRM_DEV_ERROR(panel->dev, "power_off failed ret = %d\n", ret);
+
+	pinfo->prepared = false;
+
+	return ret;
+#endif
+}
+
+static int lg_panel_power_on(struct panel_info *pinfo)
+{
+	int ret, i;
+pr_err("In sw43408 panel_power_on\n");
+	for (i = 0; i < ARRAY_SIZE(pinfo->supplies); i++) {
+		ret = regulator_set_load(pinfo->supplies[i].consumer,
+					regulator_enable_loads[i]);
+		if (ret)
+			return ret;
+	}
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(pinfo->supplies), pinfo->supplies);
+	if (ret < 0)
+		return ret;
+
+	ret = panel_set_pinctrl_state(pinfo, true);
+	if (ret) {
+		pr_err("[%s] failed to set pinctrl, rc=%d\n", pinfo->desc->panel_name, ret);
+		return ret;
+	}
+
+	/*
+	 * Reset sequence of LG sw43408 panel requires the panel to be
+	 * out of reset for 9ms, followed by being held in reset
+	 * for 1ms and then out again
+	 */
+	gpiod_set_value(pinfo->reset_gpio, 1);
+	usleep_range(9000, 10000);
+	gpiod_set_value(pinfo->reset_gpio, 0);
+	usleep_range(1000, 2000);
+	gpiod_set_value(pinfo->reset_gpio, 1);
+	usleep_range(9000, 10000);
+
+	return 0;
+}
+
+static int lg_panel_prepare(struct drm_panel *panel)
+{
+	struct panel_info *pinfo = to_panel_info(panel);
+	int err;
+pr_err("In sw43408 panel_prepare\n");
+
+	if (unlikely(pinfo->first_enable)) {
+		pinfo->first_enable = false;
+		err = panel_reset_at_beginning(pinfo);
+		if (err < 0) {
+		pr_err("sw43408 panel_reset_at_beginning failed: %d\n", err);
+			return err;
+		}
+	}
+
+	if (pinfo->prepared)
+		return 0;
+
+	usleep_range(pinfo->init_delay_us, pinfo->init_delay_us);
+
+	err = lg_panel_power_on(pinfo);
+	if (err < 0)
+		goto poweroff;
+
+	/* send first part of init cmds */
+	err = send_mipi_cmds(panel, pinfo->desc->on_cmds_1);
+
+	if (err < 0) {
+		DRM_DEV_ERROR(panel->dev,
+				"failed to send DCS Init 1st Code: %d\n", err);
+		goto poweroff;
+	}
+
+	err = mipi_dsi_dcs_exit_sleep_mode(pinfo->link);
+	if (err < 0) {
+		DRM_DEV_ERROR(panel->dev, "failed to exit sleep mode: %d\n",
+			      err);
+		goto poweroff;
+	}
+	/* 0x87 = 135 ms delay */
+	msleep(135);
+
+	/* Set DCS_COMPRESSION_MODE */
+	err = mipi_dsi_dcs_write(pinfo->link, MIPI_DSI_COMPRESSION_MODE, (u8[]){ 0x11 }, 0);
+	if (err < 0) {
+		DRM_DEV_ERROR(panel->dev,
+				"failed to set compression mode: %d\n", err);
+		goto poweroff;
+	}
+
+
+	/* Send rest of the init cmds */
+	err = send_mipi_cmds(panel, pinfo->desc->on_cmds_2);
+
+	if (err < 0) {
+		DRM_DEV_ERROR(panel->dev,
+				"failed to send DCS Init 2nd Code: %d\n", err);
+		goto poweroff;
+	}
+
+	err = mipi_dsi_dcs_set_display_on(pinfo->link);
+	if (err < 0) {
+		DRM_DEV_ERROR(panel->dev,
+				"failed to Set Display ON: %d\n", err);
+		goto poweroff;
+	}
+
+	/* 0x32 = 50ms delay */
+	msleep(120);
+
+	pinfo->prepared = true;
+
+	return 0;
+
+poweroff:
+	gpiod_set_value(pinfo->reset_gpio, 1);
+	return err;
+}
+
+static int lg_panel_enable(struct drm_panel *panel)
+{
+	struct panel_info *pinfo = to_panel_info(panel);
+	int ret;
+
+	if (pinfo->enabled)
+		return 0;
+pr_err("In sw43408 panel_enable\n");
+	ret = backlight_enable(pinfo->backlight);
+	if (ret) {
+		DRM_DEV_ERROR(panel->dev,
+				"Failed to enable backlight %d\n", ret);
+		return ret;
+	}
+
+	pinfo->enabled = true;
+
+	return 0;
+}
+
+static int lg_panel_get_modes(struct drm_panel *panel,
+			      struct drm_connector *connector)
+{
+	struct panel_info *pinfo = to_panel_info(panel);
+	const struct drm_display_mode *m = pinfo->desc->display_mode;
+	struct drm_display_mode *mode;
+pr_err("In sw43408 panel_get_modes\n");
+	mode = drm_mode_duplicate(connector->dev, m);
+	if (!mode) {
+		DRM_DEV_ERROR(panel->dev, "failed to add mode %ux%u@%u\n",
+				m->hdisplay, m->vdisplay, drm_mode_vrefresh(m));
+		return -ENOMEM;
+	}
+
+	connector->display_info.width_mm = pinfo->desc->width_mm;
+	connector->display_info.height_mm = pinfo->desc->height_mm;
+
+	drm_mode_set_name(mode);
+	drm_mode_probed_add(connector, mode);
+
+	return 1;
+}
+
+static int lg_panel_backlight_update_status(struct backlight_device *bl)
+{
+	struct panel_info *pinfo = bl_get_data(bl);
+	int ret = 0;
+
+	if (bl->props.power != FB_BLANK_UNBLANK ||
+	    bl->props.fb_blank != FB_BLANK_UNBLANK ||
+	    bl->props.state & BL_CORE_FBBLANK) {
+		pinfo->brightness = 0;
+	}
+	else
+		pinfo->brightness = bl->props.brightness;
+
+pr_err("sw43408: panel_backlight_update_status: setting brightness to: %d\n", pinfo->brightness);
+
+	ret = mipi_dsi_dcs_set_display_brightness(pinfo->link,
+					pinfo->brightness);
+pr_err("sw43408: mipi_dsi_dcs_set_display_brightness returned : %d\n", ret);
+
+	return ret;
+}
+
+static int lg_panel_backlight_get_brightness(struct backlight_device *bl)
+{
+	struct panel_info *pinfo = bl_get_data(bl);
+	int ret = 0;
+	u16 brightness = 0;
+
+	ret = mipi_dsi_dcs_get_display_brightness(pinfo->link, &brightness);
+pr_err("sw43408: panel_backlight_get_brightness: current brightness is: %d, ret: %d\n", brightness, ret);
+	if (ret < 0)
+		return ret;
+
+	return brightness & 0xff;
+}
+
+const struct backlight_ops lg_panel_backlight_ops = {
+	.update_status = lg_panel_backlight_update_status,
+	.get_brightness = lg_panel_backlight_get_brightness,
+};
+
+static int lg_panel_backlight_init(struct panel_info *pinfo)
+{
+	struct backlight_properties props = {};
+	struct backlight_device	*bl;
+	struct device *dev = &pinfo->link->dev;
+
+pr_err("sw43408: panel_backlight_init\n");
+	props.type = BACKLIGHT_RAW;
+
+	// Set the max_brightness to 255 to begin with
+	props.max_brightness = pinfo->max_brightness = 255;
+	props.brightness = pinfo->max_brightness;
+	pinfo->brightness = pinfo->max_brightness;
+	bl = devm_backlight_device_register(dev, "lg-sw43408", dev, pinfo,
+					     &lg_panel_backlight_ops, &props);
+	if (IS_ERR(bl)) {
+		DRM_ERROR("failed to register backlight device\n");
+		return PTR_ERR(bl);
+	}
+	pinfo->backlight = bl;
+
+	return 0;
+}
+
+
+static const struct drm_panel_funcs panel_funcs = {
+	.disable = lg_panel_disable,
+	.unprepare = lg_panel_unprepare,
+	.prepare = lg_panel_prepare,
+	.enable = lg_panel_enable,
+	.get_modes = lg_panel_get_modes,
+};
+
+static const struct panel_cmd lg_sw43408_on_cmds_1[] = {
+	_INIT_CMD(0x00, 0x26, 0x02),	// MIPI_DCS_SET_GAMMA_CURVE, 0x02
+	_INIT_CMD(0x00, 0x35, 0x00),	// MIPI_DCS_SET_TEAR_ON
+	_INIT_CMD(0x00, 0x53, 0x0C, 0x30),
+	_INIT_CMD(0x00, 0x55, 0x00, 0x70, 0xDF, 0x00, 0x70, 0xDF),
+	_INIT_CMD(0x00, 0xF7, 0x01, 0x49, 0x0C),
+
+	{},
+};
+
+static const struct panel_cmd lg_sw43408_on_cmds_2[] = {
+	_INIT_CMD(0x00, 0xB0, 0xAC),
+	_INIT_CMD(0x00, 0xCD,
+			0x00, 0x00, 0x00, 0x19, 0x19, 0x19, 0x19, 0x19,
+			0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19, 0x19,
+			0x16, 0x16),
+	_INIT_CMD(0x00, 0xCB, 0x80, 0x5C, 0x07, 0x03, 0x28),
+	_INIT_CMD(0x00, 0xC0, 0x02, 0x02, 0x0F),
+	_INIT_CMD(0x00, 0xE5, 0x00, 0x3A, 0x00, 0x3A, 0x00, 0x0E, 0x10),
+	_INIT_CMD(0x00, 0xB5,
+			0x75, 0x60, 0x2D, 0x5D, 0x80, 0x00, 0x0A, 0x0B,
+			0x00, 0x05, 0x0B, 0x00, 0x80, 0x0D, 0x0E, 0x40,
+			0x00, 0x0C, 0x00, 0x16, 0x00, 0xB8, 0x00, 0x80,
+			0x0D, 0x0E, 0x40, 0x00, 0x0C, 0x00, 0x16, 0x00,
+			0xB8, 0x00, 0x81, 0x00, 0x03, 0x03, 0x03, 0x01,
+			0x01),
+	_INIT_CMD(0x00, 0x55, 0x04, 0x61, 0xDB, 0x04, 0x70, 0xDB),
+	_INIT_CMD(0x00, 0xB0, 0xCA),
+
+	{},
+};
+
+static const struct drm_display_mode lg_panel_default_mode = {
+	.clock		= 152340,
+
+	.hdisplay	= 1080,
+	.hsync_start	= 1080 + 20,
+	.hsync_end	= 1080 + 20 + 32,
+	.htotal		= 1080 + 20 + 32 + 20,
+
+	.vdisplay	= 2160,
+	.vsync_start	= 2160 + 20,
+	.vsync_end	= 2160 + 20 + 4,
+	.vtotal		= 2160 + 20 + 4 + 20,
+
+	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+};
+
+static const struct panel_desc lg_panel_desc = {
+	.display_mode = &lg_panel_default_mode,
+
+	.width_mm = 62,
+	.height_mm = 124,
+
+	.mode_flags = MIPI_DSI_MODE_LPM,
+	.format = MIPI_DSI_FMT_RGB888,
+	.lanes = 4,
+	.on_cmds_1 = lg_sw43408_on_cmds_1,
+	.on_cmds_2 = lg_sw43408_on_cmds_2,
+};
+
+
+static const struct of_device_id panel_of_match[] = {
+	{ .compatible = "lg,sw43408",
+	  .data = &lg_panel_desc
+	},
+	{
+		/* sentinel */
+	}
+};
+MODULE_DEVICE_TABLE(of, panel_of_match);
+
+static int panel_pinctrl_init(struct panel_info *panel)
+{
+	struct device *dev = &panel->link->dev;
+	int rc = 0;
+
+	panel->pinctrl = devm_pinctrl_get(dev);
+	if (IS_ERR_OR_NULL(panel->pinctrl)) {
+		rc = PTR_ERR(panel->pinctrl);
+		pr_err("failed to get pinctrl, rc=%d\n", rc);
+		goto error;
+	}
+
+	panel->active = pinctrl_lookup_state(panel->pinctrl,
+							"panel_active");
+	if (IS_ERR_OR_NULL(panel->active)) {
+		rc = PTR_ERR(panel->active);
+		pr_err("failed to get pinctrl active state, rc=%d\n", rc);
+		goto error;
+	}
+
+	panel->suspend =
+		pinctrl_lookup_state(panel->pinctrl, "panel_suspend");
+
+	if (IS_ERR_OR_NULL(panel->suspend)) {
+		rc = PTR_ERR(panel->suspend);
+		pr_err("failed to get pinctrl suspend state, rc=%d\n", rc);
+		goto error;
+	}
+
+error:
+	return rc;
+}
+
+static int panel_add(struct panel_info *pinfo)
+{
+	struct device *dev = &pinfo->link->dev;
+	int i, ret;
+pr_err("In sw43408 panel add\n");
+
+	pinfo->init_delay_us = 5000;
+
+	for (i = 0; i < ARRAY_SIZE(pinfo->supplies); i++)
+		pinfo->supplies[i].supply = regulator_names[i];
+
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(pinfo->supplies),
+				      pinfo->supplies);
+	if (ret < 0)
+		return ret;
+
+	pinfo->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
+	if (IS_ERR(pinfo->reset_gpio)) {
+		DRM_DEV_ERROR(dev, "cannot get reset gpio %ld\n",
+			PTR_ERR(pinfo->reset_gpio));
+		return PTR_ERR(pinfo->reset_gpio);
+	}
+
+	ret = panel_pinctrl_init(pinfo);
+	if (ret < 0)
+		return ret;
+
+	ret = lg_panel_backlight_init(pinfo);
+	if (ret < 0)
+		return ret;
+
+	drm_panel_init(&pinfo->base, dev, &panel_funcs,
+		       DRM_MODE_CONNECTOR_DSI);
+pr_err("In sw43408 panel add: after drm_panel_init\n");
+
+	drm_panel_add(&pinfo->base);
+
+	return 0;
+}
+
+static void panel_del(struct panel_info *pinfo)
+{
+	if (pinfo->base.dev)
+		drm_panel_remove(&pinfo->base);
+}
+
+static int panel_probe(struct mipi_dsi_device *dsi)
+{
+	struct panel_info *pinfo;
+	const struct panel_desc *desc;
+	int err;
+
+	pinfo = devm_kzalloc(&dsi->dev, sizeof(*pinfo), GFP_KERNEL);
+	if (!pinfo)
+		return -ENOMEM;
+
+	desc = of_device_get_match_data(&dsi->dev);
+	dsi->mode_flags = desc->mode_flags;
+	dsi->format = desc->format;
+	dsi->lanes = desc->lanes;
+	pinfo->desc = desc;
+
+	pinfo->link = dsi;
+	mipi_dsi_set_drvdata(dsi, pinfo);
+pr_err("In sw43408 panel probe\n");
+
+	err = panel_add(pinfo);
+	if (err < 0)
+		return err;
+
+	err = mipi_dsi_attach(dsi);
+pr_err("In sw43408 panel probe: mipi_dsi_attach returned: %d\n", err);
+	return err;	
+}
+
+static int panel_remove(struct mipi_dsi_device *dsi)
+{
+	struct panel_info *pinfo = mipi_dsi_get_drvdata(dsi);
+	int err;
+
+	err = lg_panel_unprepare(&pinfo->base);
+	if (err < 0)
+		DRM_DEV_ERROR(&dsi->dev, "failed to unprepare panel: %d\n",
+				err);
+
+	err = lg_panel_disable(&pinfo->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);
+
+	drm_panel_remove(&pinfo->base);
+	panel_del(pinfo);
+
+	return 0;
+}
+
+static void panel_shutdown(struct mipi_dsi_device *dsi)
+{
+	struct panel_info *pinfo = mipi_dsi_get_drvdata(dsi);
+pr_err("sw43408: panel_shutdown\n");
+	lg_panel_disable(&pinfo->base);
+	lg_panel_unprepare(&pinfo->base);
+}
+
+static struct mipi_dsi_driver panel_driver = {
+	.driver = {
+		.name = "panel-lg-sw43408",
+		.of_match_table = panel_of_match,
+	},
+	.probe = panel_probe,
+	.remove = panel_remove,
+	.shutdown = panel_shutdown,
+};
+module_mipi_dsi_driver(panel_driver);
+
+MODULE_AUTHOR("Sumit Semwal <sumit.semwal@linaro.org>");
+MODULE_DESCRIPTION("LG SW436408 MIPI-DSI LED panel");
+MODULE_LICENSE("GPL");