diff mbox series

[4/4] drm: panel: Add lg sw43408 panel driver

Message ID 20220718213051.1475108-5-caleb@connolly.tech (mailing list archive)
State New, archived
Headers show
Series Initial support for the Pixel 3 | expand

Commit Message

Caleb Connolly July 18, 2022, 9:30 p.m. UTC
From: Sumit Semwal <sumit.semwal@linaro.org>

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

Whatever init sequence we have for this panel isn't capable of
initialising it completely, toggling the reset gpio ever causes the
panel to die. Until this is resolved we avoid resetting the panel. The
disable/unprepare functions only put the panel to sleep mode and
disable the backlight.

Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
[vinod: Add DSC support]
Signed-off-by: Vinod Koul <vkoul@kernel.org>
[caleb: cleanup and support turning off the panel]
Signed-off-by: Caleb Connolly <caleb@connolly.tech>
---
 MAINTAINERS                              |   8 +
 drivers/gpu/drm/panel/Kconfig            |  11 +
 drivers/gpu/drm/panel/Makefile           |   1 +
 drivers/gpu/drm/panel/panel-lg-sw43408.c | 586 +++++++++++++++++++++++
 4 files changed, 606 insertions(+)
 create mode 100644 drivers/gpu/drm/panel/panel-lg-sw43408.c

Comments

Dmitry Baryshkov July 18, 2022, 11:06 p.m. UTC | #1
On 19/07/2022 00:30, Caleb Connolly wrote:
> From: Sumit Semwal <sumit.semwal@linaro.org>
> 
> LG SW43408 is 1080x2160, 4-lane MIPI-DSI panel, used in some Pixel3
> phones.
> 
> Whatever init sequence we have for this panel isn't capable of
> initialising it completely, toggling the reset gpio ever causes the
> panel to die. Until this is resolved we avoid resetting the panel. The
> disable/unprepare functions only put the panel to sleep mode and
> disable the backlight.
> 
> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
> [vinod: Add DSC support]
> Signed-off-by: Vinod Koul <vkoul@kernel.org>
> [caleb: cleanup and support turning off the panel]
> Signed-off-by: Caleb Connolly <caleb@connolly.tech>
> ---
>   MAINTAINERS                              |   8 +
>   drivers/gpu/drm/panel/Kconfig            |  11 +
>   drivers/gpu/drm/panel/Makefile           |   1 +
>   drivers/gpu/drm/panel/panel-lg-sw43408.c | 586 +++++++++++++++++++++++
>   4 files changed, 606 insertions(+)
>   create mode 100644 drivers/gpu/drm/panel/panel-lg-sw43408.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index f679152bdbad..8a2b954ad140 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -6376,6 +6376,14 @@ 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>
> +M:	Caleb Connolly <caleb@connolly.tech>
> +S:	Maintained
> +T:	git git://anongit.freedesktop.org/drm/drm-misc
> +F:	Documentation/devicetree/bindings/display/panel/lg,sw43408-panel.txt
> +F:	drivers/gpu/drm/panel/panel-lg-sw43408.c
> +
>   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 38799effd00a..706b112794b9 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -256,6 +256,17 @@ 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 42a7ab54234b..ba26a69b74e7 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -25,6 +25,7 @@ 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-$(CONFIG_DRM_PANEL_NEWVISION_NV3052C) += panel-newvision-nv3052c.o
>   obj-$(CONFIG_DRM_PANEL_NOVATEK_NT35510) += panel-novatek-nt35510.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..c7b8ec7b970d
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-lg-sw43408.c
> @@ -0,0 +1,586 @@
> +// 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/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 <drm/display/drm_dsc.h>
> +#include <drm/display/drm_dsc_helper.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",
> +};
> +
> +static const unsigned long regulator_enable_loads[] = {
> +	62000,
> +	857000,
> +};
> +
> +static const unsigned long regulator_disable_loads[] = {
> +	80,
> +	0,
> +};
> +
> +struct sw43408_panel {
> +	struct drm_panel base;
> +	struct mipi_dsi_device *link;
> +
> +	const struct drm_display_mode *mode;
> +	struct backlight_device *backlight;
> +
> +	struct regulator_bulk_data supplies[ARRAY_SIZE(regulator_names)];
> +
> +	struct gpio_desc *reset_gpio;
> +
> +	bool prepared;
> +	bool enabled;
> +};
> +
> +static const struct panel_cmd lg_sw43408_on_cmds_1[] = {
> +	_INIT_CMD(0x00, 0x53, 0x0C, 0x30),

Please use the lower case for hex numbers.

> +	_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),

The dtbo from the latest firware uses a bit different sequence here:

0xb0, 0xac
0xe5, 0x00....
0xb5, 0x75.....
msleep(85);
0xcd, 0x00.....
0xcb, 0x80...
0x55, 0x04...
0xb0, 0xca

I'm not sure, but granted that you have issues with panel reinit, maybe 
that would make any difference.

> +
> +	{},
> +};
> +
> +static inline struct sw43408_panel *to_panel_info(struct drm_panel *panel)
> +{
> +	return container_of(panel, struct sw43408_panel, base);
> +}
> +
> +/*
> + * Currently unable to bring up the panel after resetting, must be missing
> + * some init commands somewhere.
> + */
> +static __always_unused int panel_reset(struct sw43408_panel *ctx)
> +{
> +	int ret = 0, i;
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		ret = regulator_set_load(ctx->supplies[i].consumer,
> +					 regulator_enable_loads[i]);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	if (ret < 0)
> +		return ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		ret = regulator_set_load(ctx->supplies[i].consumer,
> +					 regulator_disable_loads[i]);
> +		if (ret) {
> +			DRM_DEV_ERROR(ctx->base.dev,
> +				      "regulator_set_load failed %d\n", ret);
> +			return ret;
> +		}
> +	}

If I remember correctly, there is no need to set loads before disabling 
the regulator.

> +
> +	ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	if (ret < 0)
> +		return ret;

So, you bump & disable regulators before playing with the reset GPIO. 
Does the panel honour reset GPIO while being powered down?

> +
> +	gpiod_set_value(ctx->reset_gpio, 0);
> +	usleep_range(9000, 10000);
> +	gpiod_set_value(ctx->reset_gpio, 1);
> +	usleep_range(1000, 2000);
> +	gpiod_set_value(ctx->reset_gpio, 0);
> +	usleep_range(9000, 10000);
> +
> +	return 0;
> +}
> +
> +static int send_mipi_cmds(struct drm_panel *panel, const struct panel_cmd *cmds)
> +{
> +	struct sw43408_panel *ctx = 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(ctx->link, cmd->data[1], NULL,
> +						 0);
> +		else
> +			err = mipi_dsi_dcs_write(ctx->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 lg_panel_disable(struct drm_panel *panel)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +
> +	backlight_disable(ctx->backlight);
> +	ctx->enabled = false;
> +
> +	return 0;
> +}
> +
> +/*
> + * We can't currently re-initialise the panel properly after powering off.
> + * This function will be used when this is resolved.
> + */
> +static __always_unused int lg_panel_power_off(struct drm_panel *panel)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	int i, ret = 0;
> +
> +	gpiod_set_value(ctx->reset_gpio, 1);
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		ret = regulator_set_load(ctx->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(ctx->supplies), ctx->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)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	int ret, i;
> +
> +	if (!ctx->prepared)
> +		return 0;
> +
> +	ret = mipi_dsi_dcs_set_display_off(ctx->link);
> +	if (ret < 0) {
> +		DRM_DEV_ERROR(panel->dev,
> +			      "set_display_off cmd failed ret = %d\n", ret);
> +	}
> +
> +	msleep(120);
> +
> +	ret = mipi_dsi_dcs_enter_sleep_mode(ctx->link);
> +	if (ret < 0) {
> +		DRM_DEV_ERROR(panel->dev, "enter_sleep cmd failed ret = %d\n",
> +			      ret);
> +	}
> +
> +	/* Would call panel_power_off() */
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		ret = regulator_set_load(ctx->supplies[i].consumer,
> +					 regulator_disable_loads[i]);
> +		if (ret) {
> +			DRM_DEV_ERROR(panel->dev,
> +				      "regulator_set_load failed %d\n", ret);
> +			return ret;
> +		}
> +	}

Do you need to disable regulators instead?
Also would you need to pull the reset gpio?

> +
> +	ctx->prepared = false;
> +
> +	return ret;
> +}
> +
> +static int lg_panel_prepare(struct drm_panel *panel)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	int err, i;
> +
> +	if (ctx->prepared)
> +		return 0;
> +
> +	/* Would call panel_reset() */
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		err = regulator_set_load(ctx->supplies[i].consumer,
> +					 regulator_enable_loads[i]);
> +		if (err)
> +			return err;
> +	}
> +
> +	err = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	if (err < 0)
> +		return err;
> +
> +	usleep_range(9000, 10000);

Reset the panel here?

> +
> +	err = mipi_dsi_dcs_write(ctx->link, MIPI_DCS_SET_GAMMA_CURVE,
> +				 (u8[]){ 0x02 }, 1);
> +	if (err < 0) {
> +		DRM_DEV_ERROR(panel->dev, "failed to set gamma curve: %d\n",
> +			      err);
> +		goto poweroff;
> +	}
> +
> +	err = mipi_dsi_dcs_set_tear_on(ctx->link,
> +				       MIPI_DSI_DCS_TEAR_MODE_VBLANK);
> +	if (err < 0) {
> +		DRM_DEV_ERROR(panel->dev, "failed to set tear on: %d\n", err);
> +		goto poweroff;
> +	}
> +
> +	err = send_mipi_cmds(panel, &lg_sw43408_on_cmds_1[0]);
> +
> +	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(ctx->link);
> +	if (err < 0) {
> +		DRM_DEV_ERROR(panel->dev, "failed to exit sleep mode: %d\n",
> +			      err);
> +		goto poweroff;
> +	}
> +
> +	msleep(135);
> +
> +	err = mipi_dsi_dcs_write(ctx->link, MIPI_DSI_COMPRESSION_MODE,
> +				 (u8[]){ 0x11 }, 0);

Please adjust mipi_dsi_compression_mode() instead. Do you really need 
0x11 here? Does 0x1 work? You might want to adjust the mentioned function.

> +	if (err < 0) {
> +		DRM_DEV_ERROR(panel->dev,
> +			      "failed to set compression mode: %d\n", err);
> +		goto poweroff;
> +	}
> +
> +	err = send_mipi_cmds(panel, &lg_sw43408_on_cmds_2[0]);
> +
> +	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(ctx->link);
> +	if (err < 0) {
> +		DRM_DEV_ERROR(panel->dev, "failed to Set Display ON: %d\n",
> +			      err);
> +		goto poweroff;
> +	}
> +
> +	msleep(120);
> +
> +	ctx->prepared = true;
> +
> +	return 0;
> +
> +poweroff:
> +	gpiod_set_value(ctx->reset_gpio, 1);
> +	regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	return err;
> +}
> +
> +static int lg_panel_enable(struct drm_panel *panel)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	struct drm_dsc_picture_parameter_set pps;
> +	int ret;
> +
> +	if (ctx->enabled)
> +		return 0;
> +
> +	ret = backlight_enable(ctx->backlight);
> +	if (ret) {
> +		DRM_DEV_ERROR(panel->dev, "Failed to enable backlight %d\n",
> +			      ret);
> +		return ret;
> +	}

Do you need to enable the backlight beforehand (well, before sending the 
pps?) drm_panel_enable() would enable the backlight for you.

> +
> +	if (!panel->dsc) {
> +		DRM_DEV_ERROR(panel->dev, "Can't find DSC\n");
> +		return -ENODEV;
> +	}
> +
> +	drm_dsc_pps_payload_pack(&pps, panel->dsc);

Do you need to call mipi_dsi_picture_parameter_set() here? Otherwise 
genrated pps is not used at all.

> +
> +	ctx->enabled = true;
> +
> +	return 0;
> +}
> +
> +static int lg_panel_get_modes(struct drm_panel *panel,
> +			      struct drm_connector *connector)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	const struct drm_display_mode *m = ctx->mode;
> +	struct drm_display_mode *mode;
> +
> +	mode = drm_mode_duplicate(connector->dev, m);
> +	if (!mode) {
> +		DRM_DEV_ERROR(panel->dev, "failed to add mode %ux%u\n",
> +			      m->hdisplay, m->vdisplay);
> +		return -ENOMEM;
> +	}
> +
> +	connector->display_info.width_mm = m->width_mm;
> +	connector->display_info.height_mm = m->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 mipi_dsi_device *dsi = bl_get_data(bl);
> +	int ret = 0;
> +	uint16_t brightness;

u16

> +
> +	brightness = (uint16_t)backlight_get_brightness(bl);

Probably no need to cast here.

> +	/* Brightness is sent in big-endian */
> +	brightness = cpu_to_be16(brightness);
> +
> +	ret = mipi_dsi_dcs_set_display_brightness(dsi, brightness);

lmdpdg.py suggest that this (and get_display_brightnees()) should be 
wrapped into disabling and reenabling MIPI_DSI_MODE_LPM in dsi->mode_flags.

> +	return ret;
> +}
> +
> +static int lg_panel_backlight_get_brightness(struct backlight_device *bl)
> +{
> +	struct mipi_dsi_device *dsi = bl_get_data(bl);
> +	int ret = 0;
> +	u16 brightness = 0;
> +
> +	ret = mipi_dsi_dcs_get_display_brightness(dsi, &brightness);
> +	if (ret < 0)
> +		return ret;
> +
> +	return brightness & 0xff;

So the brighness is sent as be16, but doesn't require handling on 
get_brightness?

> +}
> +
> +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 sw43408_panel *ctx)
> +{
> +	struct device *dev = &ctx->link->dev;
> +	const struct backlight_properties props = {
> +		.type = BACKLIGHT_PLATFORM,
> +		.brightness = 255,
> +		.max_brightness = 255,

900, according to the dtsi

> +	};
> +
> +	ctx->backlight = devm_backlight_device_register(dev, dev_name(dev), dev,
> +							ctx->link,
> +							&lg_panel_backlight_ops,
> +							&props);
> +
> +	if (IS_ERR(ctx->backlight))
> +		return dev_err_probe(dev, PTR_ERR(ctx->backlight),
> +				     "Failed to create backlight\n");
> +
> +	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 drm_display_mode sw43408_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,
> +
> +	.width_mm = 62,
> +	.height_mm = 124,
> +
> +	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
> +};
> +
> +static const struct of_device_id panel_of_match[] = {
> +	{ .compatible = "lg,sw43408", .data = &sw43408_default_mode },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, panel_of_match);
> +
> +static int panel_add(struct sw43408_panel *ctx)
> +{
> +	struct device *dev = &ctx->link->dev;
> +	int i, ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++)
> +		ctx->supplies[i].supply = regulator_names[i];
> +
> +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ctx->supplies),
> +				      ctx->supplies);
> +	if (ret < 0)
> +		return ret;
> +
> +	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(ctx->reset_gpio)) {
> +		DRM_DEV_ERROR(dev, "cannot get reset gpio %ld\n",
> +			      PTR_ERR(ctx->reset_gpio));
> +		return PTR_ERR(ctx->reset_gpio);
> +	}
> +
> +	ret = lg_panel_backlight_init(ctx);
> +	if (ret < 0)
> +		return ret;
> +
> +	drm_panel_init(&ctx->base, dev, &panel_funcs, DRM_MODE_CONNECTOR_DSI);
> +
> +	drm_panel_add(&ctx->base);
> +	return ret;
> +}
> +
> +static int panel_probe(struct mipi_dsi_device *dsi)
> +{
> +	struct sw43408_panel *ctx;
> +	struct drm_dsc_config *dsc;
> +	int err;
> +
> +	ctx = devm_kzalloc(&dsi->dev, sizeof(*ctx), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	ctx->mode = of_device_get_match_data(&dsi->dev);
> +	dsi->mode_flags = MIPI_DSI_MODE_LPM;
> +	dsi->format = MIPI_DSI_FMT_RGB888;
> +	dsi->lanes = 4;
> +
> +	ctx->link = dsi;
> +	mipi_dsi_set_drvdata(dsi, ctx);
> +
> +	err = panel_add(ctx);
> +	if (err < 0)
> +		return err;
> +
> +	/* The panel is DSC panel only, set the dsc params */
> +	dsc = devm_kzalloc(&dsi->dev, sizeof(*dsc), GFP_KERNEL);
> +	if (!dsc)
> +		return -ENOMEM;
> +
> +	dsc->dsc_version_major = 0x1;
> +	dsc->dsc_version_minor = 0x1;
> +
> +	dsc->slice_height = 16;
> +	dsc->slice_width = 540;
> +	dsc->slice_count = 1;
> +	dsc->bits_per_component = 8;
> +	dsc->bits_per_pixel = 8;
> +	dsc->block_pred_enable = true;
> +
> +	ctx->base.dsc = dsc;

I was really hoping to move DSC PPS data to struct mipi_dsi_device, 
before DSC panel drivers start to pop up.

See 
https://lore.kernel.org/linux-arm-msm/20220711094320.368062-2-dmitry.baryshkov@linaro.org/

> +
> +	return mipi_dsi_attach(dsi);
> +}
> +
> +static int panel_remove(struct mipi_dsi_device *dsi)
> +{
> +	struct sw43408_panel *ctx = mipi_dsi_get_drvdata(dsi);
> +	int err;
> +
> +	err = lg_panel_unprepare(&ctx->base);
> +	if (err < 0)
> +		DRM_DEV_ERROR(&dsi->dev, "failed to unprepare panel: %d\n",
> +			      err);
> +
> +	err = lg_panel_disable(&ctx->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);
> +
> +	if (ctx->base.dev)
> +		drm_panel_remove(&ctx->base);
> +
> +	return 0;
> +}
> +
> +static struct mipi_dsi_driver panel_driver = {
> +	.driver = {
> +		.name = "panel-lg-sw43408",
> +		.of_match_table = panel_of_match,
> +	},
> +	.probe = panel_probe,
> +	.remove = panel_remove,
> +};
> +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");
Sam Ravnborg July 19, 2022, 7:48 a.m. UTC | #2
Hi Caleb,

On Mon, Jul 18, 2022 at 10:30:51PM +0100, Caleb Connolly wrote:
> From: Sumit Semwal <sumit.semwal@linaro.org>
> 
> LG SW43408 is 1080x2160, 4-lane MIPI-DSI panel, used in some Pixel3
> phones.

Thanks for submitting this.

When reading the code it is obvious that this was based on an older
panel and there is a few things to improve to get it on on same level as
the other panel drivers today.

I will comment in the following.

	Sam

> 
> Whatever init sequence we have for this panel isn't capable of
> initialising it completely, toggling the reset gpio ever causes the
> panel to die. Until this is resolved we avoid resetting the panel. The
> disable/unprepare functions only put the panel to sleep mode and
> disable the backlight.
> 
> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
> [vinod: Add DSC support]
> Signed-off-by: Vinod Koul <vkoul@kernel.org>
> [caleb: cleanup and support turning off the panel]
> Signed-off-by: Caleb Connolly <caleb@connolly.tech>
> ---
>  MAINTAINERS                              |   8 +
>  drivers/gpu/drm/panel/Kconfig            |  11 +
>  drivers/gpu/drm/panel/Makefile           |   1 +
>  drivers/gpu/drm/panel/panel-lg-sw43408.c | 586 +++++++++++++++++++++++
>  4 files changed, 606 insertions(+)
>  create mode 100644 drivers/gpu/drm/panel/panel-lg-sw43408.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index f679152bdbad..8a2b954ad140 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -6376,6 +6376,14 @@ 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>
> +M:	Caleb Connolly <caleb@connolly.tech>
> +S:	Maintained
m +T:	git git://anongit.freedesktop.org/drm/drm-misc
> +F:	Documentation/devicetree/bindings/display/panel/lg,sw43408-panel.txt
> +F:	drivers/gpu/drm/panel/panel-lg-sw43408.c
> +
>  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 38799effd00a..706b112794b9 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -256,6 +256,17 @@ 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.
> +

Hrmpf, the DRM_PANEL_SAMSUNG_LD9040 config entry is not placed in
alphabetic order. Can you move it or put you config optiosn with the
other LG config options?

>  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 42a7ab54234b..ba26a69b74e7 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -25,6 +25,7 @@ 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-$(CONFIG_DRM_PANEL_NEWVISION_NV3052C) += panel-newvision-nv3052c.o
>  obj-$(CONFIG_DRM_PANEL_NOVATEK_NT35510) += panel-novatek-nt35510.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..c7b8ec7b970d
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-lg-sw43408.c
> @@ -0,0 +1,586 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * Copyright (C) 2019 Linaro Ltd
Update to 2022?

> + * 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/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 <drm/display/drm_dsc.h>
> +#include <drm/display/drm_dsc_helper.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__                                      \
> +		}                                                        \
> +	}
Other panel drivers do:
#define _INIT_DCS_CMD(...) { \
        .type = INIT_DCS_CMD, \
        .len = sizeof((char[]){__VA_ARGS__}), \
        .data = (char[]){__VA_ARGS__} }

See for example panel-boe-tv101wum-nl6.c
This makes the init sequences a tad more readable.


> +
> +static const char *const regulator_names[] = {
> +	"vddi",
> +	"vpnl",
> +};
> +
> +static const unsigned long regulator_enable_loads[] = {
> +	62000,
> +	857000,
> +};
> +
> +static const unsigned long regulator_disable_loads[] = {
> +	80,
> +	0,
> +};
> +
> +struct sw43408_panel {
> +	struct drm_panel base;
> +	struct mipi_dsi_device *link;
This is often named "dsi"

> +
> +	const struct drm_display_mode *mode;
> +	struct backlight_device *backlight;
Unless there are specific needs, use the drm_panel provided backlight.

> +
> +	struct regulator_bulk_data supplies[ARRAY_SIZE(regulator_names)];
> +
> +	struct gpio_desc *reset_gpio;
> +
> +	bool prepared;
> +	bool enabled;
> +};
> +
> +static const struct panel_cmd lg_sw43408_on_cmds_1[] = {
> +	_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 inline struct sw43408_panel *to_panel_info(struct drm_panel *panel)
> +{
> +	return container_of(panel, struct sw43408_panel, base);
> +}
> +
> +/*
> + * Currently unable to bring up the panel after resetting, must be missing
> + * some init commands somewhere.
> + */
> +static __always_unused int panel_reset(struct sw43408_panel *ctx)
> +{
> +	int ret = 0, i;
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		ret = regulator_set_load(ctx->supplies[i].consumer,
> +					 regulator_enable_loads[i]);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	if (ret < 0)
> +		return ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		ret = regulator_set_load(ctx->supplies[i].consumer,
> +					 regulator_disable_loads[i]);
> +		if (ret) {
> +			DRM_DEV_ERROR(ctx->base.dev,
> +				      "regulator_set_load failed %d\n", ret);
panels do not use DRM_DEV_ERROR() these days. Use dev_err() or pr_err().

> +			return ret;
> +		}
> +	}
> +
> +	ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	if (ret < 0)
> +		return ret;
> +
> +	gpiod_set_value(ctx->reset_gpio, 0);
> +	usleep_range(9000, 10000);
> +	gpiod_set_value(ctx->reset_gpio, 1);
> +	usleep_range(1000, 2000);
> +	gpiod_set_value(ctx->reset_gpio, 0);
> +	usleep_range(9000, 10000);
> +
> +	return 0;
> +}
> +
> +static int send_mipi_cmds(struct drm_panel *panel, const struct panel_cmd *cmds)
> +{
> +	struct sw43408_panel *ctx = 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(ctx->link, cmd->data[1], NULL,
> +						 0);
Do not wrap lines like this, up to 100 chars is ok.

There is no use of len == 2 - as there is none with this length. Maybe
error out there is one as this is likely a bug?

> +		else
> +			err = mipi_dsi_dcs_write(ctx->link, cmd->data[1],
> +						 cmd->data + 2, cmd->len - 2);
> +
Consider to use mipi_dsi_dcs_write_buffer

> +		if (err < 0)
> +			return err;
> +
> +		usleep_range((cmd->data[0]) * 1000, (1 + cmd->data[0]) * 1000);
So there is always a usleep_range(0, 1000) after each write - is this
really required?
Also, it is non-obvious that the first byte in the arry is a delay
parameter, this can be done better. See panel-boe-tv101wum-nl6.c as one
example - there may be betters ways to do it.

> +	}
> +
> +	return 0;
> +}
> +
> +static int lg_panel_disable(struct drm_panel *panel)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +
> +	backlight_disable(ctx->backlight);
> +	ctx->enabled = false;
> +
> +	return 0;
> +}
Let drm_panel handle backlight, then you can drop the disable method.

> +
> +/*
> + * We can't currently re-initialise the panel properly after powering off.
> + * This function will be used when this is resolved.
> + */
> +static __always_unused int lg_panel_power_off(struct drm_panel *panel)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	int i, ret = 0;
> +
> +	gpiod_set_value(ctx->reset_gpio, 1);
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		ret = regulator_set_load(ctx->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(ctx->supplies), ctx->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)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	int ret, i;
> +
> +	if (!ctx->prepared)
> +		return 0;
> +
> +	ret = mipi_dsi_dcs_set_display_off(ctx->link);
> +	if (ret < 0) {
> +		DRM_DEV_ERROR(panel->dev,
> +			      "set_display_off cmd failed ret = %d\n", ret);
> +	}
> +
> +	msleep(120);
> +
> +	ret = mipi_dsi_dcs_enter_sleep_mode(ctx->link);
> +	if (ret < 0) {
> +		DRM_DEV_ERROR(panel->dev, "enter_sleep cmd failed ret = %d\n",
> +			      ret);
> +	}
> +
> +	/* Would call panel_power_off() */
And please do so.
If the reset code is not OK then comment it out in power_off(),
but do not duplicate all the regulator handling - it is very confusing
to read.
Same with the other commented out functions.

I did not look at the unprepare code - this will wait until next
iteration of the driver where the power supply stuff is cleaned up.

> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		ret = regulator_set_load(ctx->supplies[i].consumer,
> +					 regulator_disable_loads[i]);
> +		if (ret) {
> +			DRM_DEV_ERROR(panel->dev,
> +				      "regulator_set_load failed %d\n", ret);
> +			return ret;
> +		}
> +	}
> +
> +	ctx->prepared = false;
> +
> +	return ret;
> +}
> +
> +static int lg_panel_prepare(struct drm_panel *panel)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	int err, i;
> +
> +	if (ctx->prepared)
> +		return 0;
> +
> +	/* Would call panel_reset() */
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		err = regulator_set_load(ctx->supplies[i].consumer,
> +					 regulator_enable_loads[i]);
> +		if (err)
> +			return err;
> +	}
> +
> +	err = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	if (err < 0)
> +		return err;
> +
> +	usleep_range(9000, 10000);
> +
> +	err = mipi_dsi_dcs_write(ctx->link, MIPI_DCS_SET_GAMMA_CURVE,
> +				 (u8[]){ 0x02 }, 1);
> +	if (err < 0) {
> +		DRM_DEV_ERROR(panel->dev, "failed to set gamma curve: %d\n",
> +			      err);
> +		goto poweroff;
> +	}
> +
> +	err = mipi_dsi_dcs_set_tear_on(ctx->link,
> +				       MIPI_DSI_DCS_TEAR_MODE_VBLANK);
> +	if (err < 0) {
> +		DRM_DEV_ERROR(panel->dev, "failed to set tear on: %d\n", err);
> +		goto poweroff;
> +	}
> +
> +	err = send_mipi_cmds(panel, &lg_sw43408_on_cmds_1[0]);
> +
> +	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(ctx->link);
> +	if (err < 0) {
> +		DRM_DEV_ERROR(panel->dev, "failed to exit sleep mode: %d\n",
> +			      err);
> +		goto poweroff;
> +	}
> +
> +	msleep(135);
> +
> +	err = mipi_dsi_dcs_write(ctx->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;
> +	}
> +
> +	err = send_mipi_cmds(panel, &lg_sw43408_on_cmds_2[0]);
> +
> +	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(ctx->link);
> +	if (err < 0) {
> +		DRM_DEV_ERROR(panel->dev, "failed to Set Display ON: %d\n",
> +			      err);
> +		goto poweroff;
> +	}
> +
> +	msleep(120);
> +
> +	ctx->prepared = true;
> +
> +	return 0;
> +
> +poweroff:
> +	gpiod_set_value(ctx->reset_gpio, 1);
> +	regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	return err;
> +}
> +
> +static int lg_panel_enable(struct drm_panel *panel)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	struct drm_dsc_picture_parameter_set pps;
> +	int ret;
> +
> +	if (ctx->enabled)
> +		return 0;
> +
> +	ret = backlight_enable(ctx->backlight);
> +	if (ret) {
> +		DRM_DEV_ERROR(panel->dev, "Failed to enable backlight %d\n",
> +			      ret);
> +		return ret;
> +	}
> +
> +	if (!panel->dsc) {
> +		DRM_DEV_ERROR(panel->dev, "Can't find DSC\n");
> +		return -ENODEV;
> +	}
> +
> +	drm_dsc_pps_payload_pack(&pps, panel->dsc);
There is nothing in disable about pps_payload - so they are not
symmetrical. Check if this is OK.

> +
> +	ctx->enabled = true;
> +
> +	return 0;
> +}
> +
> +static int lg_panel_get_modes(struct drm_panel *panel,
> +			      struct drm_connector *connector)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	const struct drm_display_mode *m = ctx->mode;
> +	struct drm_display_mode *mode;
> +
> +	mode = drm_mode_duplicate(connector->dev, m);
> +	if (!mode) {
> +		DRM_DEV_ERROR(panel->dev, "failed to add mode %ux%u\n",
> +			      m->hdisplay, m->vdisplay);
> +		return -ENOMEM;
> +	}
> +
> +	connector->display_info.width_mm = m->width_mm;
> +	connector->display_info.height_mm = m->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 mipi_dsi_device *dsi = bl_get_data(bl);
> +	int ret = 0;
> +	uint16_t brightness;
> +
> +	brightness = (uint16_t)backlight_get_brightness(bl);
> +	/* Brightness is sent in big-endian */
> +	brightness = cpu_to_be16(brightness);
This cpu_to_be16() looks wrong - the mipi_dsi_dcs_set_display_brightness() takes care.


> +
> +	ret = mipi_dsi_dcs_set_display_brightness(dsi, brightness);
> +	return ret;
> +}
> +
> +static int lg_panel_backlight_get_brightness(struct backlight_device *bl)
> +{
> +	struct mipi_dsi_device *dsi = bl_get_data(bl);
> +	int ret = 0;
> +	u16 brightness = 0;
> +
> +	ret = mipi_dsi_dcs_get_display_brightness(dsi, &brightness);
> +	if (ret < 0)
> +		return ret;
> +
> +	return brightness & 0xff;
The truncation to 8 bit is not needed unless the HW is buggy.
And since the brightness value is not adjusted, there is no need to add
the get_brightness() method, it will just return what was written
earlier anyway. Most panels get away without it.

> +}
> +
> +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 sw43408_panel *ctx)
> +{
> +	struct device *dev = &ctx->link->dev;
> +	const struct backlight_properties props = {
> +		.type = BACKLIGHT_PLATFORM,
This is not a PLATFORM backlight, RAW it the right choice here.

> +		.brightness = 255,
> +		.max_brightness = 255,
Is 255 the correct max here? Check the HW specs.
> +	};
> +
> +	ctx->backlight = devm_backlight_device_register(dev, dev_name(dev), dev,
> +							ctx->link,
> +							&lg_panel_backlight_ops,
> +							&props);
Use panel->backlight here.

> +
> +	if (IS_ERR(ctx->backlight))
> +		return dev_err_probe(dev, PTR_ERR(ctx->backlight),
> +				     "Failed to create backlight\n");
> +
> +	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 drm_display_mode sw43408_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,
> +
> +	.width_mm = 62,
> +	.height_mm = 124,
> +
> +	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
> +};
> +
> +static const struct of_device_id panel_of_match[] = {
> +	{ .compatible = "lg,sw43408", .data = &sw43408_default_mode },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, panel_of_match);
> +
> +static int panel_add(struct sw43408_panel *ctx)
> +{
> +	struct device *dev = &ctx->link->dev;
> +	int i, ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++)
> +		ctx->supplies[i].supply = regulator_names[i];
> +
> +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ctx->supplies),
> +				      ctx->supplies);
> +	if (ret < 0)
> +		return ret;
> +
> +	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(ctx->reset_gpio)) {
> +		DRM_DEV_ERROR(dev, "cannot get reset gpio %ld\n",
> +			      PTR_ERR(ctx->reset_gpio));
> +		return PTR_ERR(ctx->reset_gpio);
> +	}
Use dev_err_probe() here.

> +
> +	ret = lg_panel_backlight_init(ctx);
> +	if (ret < 0)
> +		return ret;
> +
> +	drm_panel_init(&ctx->base, dev, &panel_funcs, DRM_MODE_CONNECTOR_DSI);
Init backlight after panel init.

> +
> +	drm_panel_add(&ctx->base);
> +	return ret;
> +}
> +
> +static int panel_probe(struct mipi_dsi_device *dsi)
> +{
> +	struct sw43408_panel *ctx;
> +	struct drm_dsc_config *dsc;
> +	int err;
> +
> +	ctx = devm_kzalloc(&dsi->dev, sizeof(*ctx), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	ctx->mode = of_device_get_match_data(&dsi->dev);
> +	dsi->mode_flags = MIPI_DSI_MODE_LPM;
> +	dsi->format = MIPI_DSI_FMT_RGB888;
> +	dsi->lanes = 4;
> +
> +	ctx->link = dsi;
> +	mipi_dsi_set_drvdata(dsi, ctx);
> +
> +	err = panel_add(ctx);
> +	if (err < 0)
> +		return err;
> +
> +	/* The panel is DSC panel only, set the dsc params */
> +	dsc = devm_kzalloc(&dsi->dev, sizeof(*dsc), GFP_KERNEL);
> +	if (!dsc)
> +		return -ENOMEM;
The drm_dsc_config could be embedded in sw43408_panel, so there was not
two allocations to track but with devm_kzalloc this is not a big win.

> +
> +	dsc->dsc_version_major = 0x1;
> +	dsc->dsc_version_minor = 0x1;
> +
> +	dsc->slice_height = 16;
> +	dsc->slice_width = 540;
> +	dsc->slice_count = 1;
> +	dsc->bits_per_component = 8;
> +	dsc->bits_per_pixel = 8;
> +	dsc->block_pred_enable = true;
> +
> +	ctx->base.dsc = dsc;
> +
> +	return mipi_dsi_attach(dsi);
> +}
> +
> +static int panel_remove(struct mipi_dsi_device *dsi)
> +{
> +	struct sw43408_panel *ctx = mipi_dsi_get_drvdata(dsi);
> +	int err;
> +
> +	err = lg_panel_unprepare(&ctx->base);
> +	if (err < 0)
> +		DRM_DEV_ERROR(&dsi->dev, "failed to unprepare panel: %d\n",
> +			      err);
Use the drm_panel() functions here, do not call your own.
See for example: y030xx067a_remove()

> +
> +	err = lg_panel_disable(&ctx->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);
mipi_dsi_detach() is needed here.

> +
> +	if (ctx->base.dev)
No need to check, the pointer must be valid.
> +		drm_panel_remove(&ctx->base);
> +
> +	return 0;
> +}
> +
> +static struct mipi_dsi_driver panel_driver = {
> +	.driver = {
> +		.name = "panel-lg-sw43408",
> +		.of_match_table = panel_of_match,
> +	},
> +	.probe = panel_probe,
> +	.remove = panel_remove,
> +};
> +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");
> -- 
> 2.36.1
Marijn Suijten Oct. 1, 2022, 9:48 p.m. UTC | #3
On 2022-07-18 22:30:51, Caleb Connolly wrote:
> From: Sumit Semwal <sumit.semwal@linaro.org>
> 
> LG SW43408 is 1080x2160, 4-lane MIPI-DSI panel, used in some Pixel3
> phones.
> 
> Whatever init sequence we have for this panel isn't capable of
> initialising it completely, toggling the reset gpio ever causes the
> panel to die. Until this is resolved we avoid resetting the panel. The
> disable/unprepare functions only put the panel to sleep mode and
> disable the backlight.
> 
> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
> [vinod: Add DSC support]
> Signed-off-by: Vinod Koul <vkoul@kernel.org>
> [caleb: cleanup and support turning off the panel]
> Signed-off-by: Caleb Connolly <caleb@connolly.tech>
> ---
>  MAINTAINERS                              |   8 +
>  drivers/gpu/drm/panel/Kconfig            |  11 +
>  drivers/gpu/drm/panel/Makefile           |   1 +
>  drivers/gpu/drm/panel/panel-lg-sw43408.c | 586 +++++++++++++++++++++++
>  4 files changed, 606 insertions(+)
>  create mode 100644 drivers/gpu/drm/panel/panel-lg-sw43408.c
> 
> diff --git a/MAINTAINERS b/MAINTAINERS
> index f679152bdbad..8a2b954ad140 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -6376,6 +6376,14 @@ 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>
> +M:	Caleb Connolly <caleb@connolly.tech>
> +S:	Maintained
> +T:	git git://anongit.freedesktop.org/drm/drm-misc
> +F:	Documentation/devicetree/bindings/display/panel/lg,sw43408-panel.txt
> +F:	drivers/gpu/drm/panel/panel-lg-sw43408.c
> +
>  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 38799effd00a..706b112794b9 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -256,6 +256,17 @@ 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 42a7ab54234b..ba26a69b74e7 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -25,6 +25,7 @@ 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-$(CONFIG_DRM_PANEL_NEWVISION_NV3052C) += panel-newvision-nv3052c.o
>  obj-$(CONFIG_DRM_PANEL_NOVATEK_NT35510) += panel-novatek-nt35510.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..c7b8ec7b970d
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-lg-sw43408.c
> @@ -0,0 +1,586 @@
> +// 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/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 <drm/display/drm_dsc.h>
> +#include <drm/display/drm_dsc_helper.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",
> +};
> +
> +static const unsigned long regulator_enable_loads[] = {
> +	62000,
> +	857000,
> +};
> +
> +static const unsigned long regulator_disable_loads[] = {
> +	80,
> +	0,
> +};
> +
> +struct sw43408_panel {
> +	struct drm_panel base;
> +	struct mipi_dsi_device *link;
> +
> +	const struct drm_display_mode *mode;
> +	struct backlight_device *backlight;
> +
> +	struct regulator_bulk_data supplies[ARRAY_SIZE(regulator_names)];
> +
> +	struct gpio_desc *reset_gpio;
> +
> +	bool prepared;
> +	bool enabled;
> +};
> +
> +static const struct panel_cmd lg_sw43408_on_cmds_1[] = {
> +	_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 inline struct sw43408_panel *to_panel_info(struct drm_panel *panel)
> +{
> +	return container_of(panel, struct sw43408_panel, base);
> +}
> +
> +/*
> + * Currently unable to bring up the panel after resetting, must be missing
> + * some init commands somewhere.
> + */
> +static __always_unused int panel_reset(struct sw43408_panel *ctx)
> +{
> +	int ret = 0, i;
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		ret = regulator_set_load(ctx->supplies[i].consumer,
> +					 regulator_enable_loads[i]);
> +		if (ret)
> +			return ret;
> +	}
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	if (ret < 0)
> +		return ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		ret = regulator_set_load(ctx->supplies[i].consumer,
> +					 regulator_disable_loads[i]);
> +		if (ret) {
> +			DRM_DEV_ERROR(ctx->base.dev,
> +				      "regulator_set_load failed %d\n", ret);
> +			return ret;
> +		}
> +	}
> +
> +	ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	if (ret < 0)
> +		return ret;
> +
> +	gpiod_set_value(ctx->reset_gpio, 0);
> +	usleep_range(9000, 10000);
> +	gpiod_set_value(ctx->reset_gpio, 1);
> +	usleep_range(1000, 2000);
> +	gpiod_set_value(ctx->reset_gpio, 0);
> +	usleep_range(9000, 10000);
> +
> +	return 0;
> +}
> +
> +static int send_mipi_cmds(struct drm_panel *panel, const struct panel_cmd *cmds)
> +{
> +	struct sw43408_panel *ctx = 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(ctx->link, cmd->data[1], NULL,
> +						 0);
> +		else
> +			err = mipi_dsi_dcs_write(ctx->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 lg_panel_disable(struct drm_panel *panel)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +
> +	backlight_disable(ctx->backlight);
> +	ctx->enabled = false;
> +
> +	return 0;
> +}
> +
> +/*
> + * We can't currently re-initialise the panel properly after powering off.
> + * This function will be used when this is resolved.
> + */
> +static __always_unused int lg_panel_power_off(struct drm_panel *panel)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	int i, ret = 0;
> +
> +	gpiod_set_value(ctx->reset_gpio, 1);
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		ret = regulator_set_load(ctx->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(ctx->supplies), ctx->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)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	int ret, i;
> +
> +	if (!ctx->prepared)
> +		return 0;
> +
> +	ret = mipi_dsi_dcs_set_display_off(ctx->link);
> +	if (ret < 0) {
> +		DRM_DEV_ERROR(panel->dev,
> +			      "set_display_off cmd failed ret = %d\n", ret);
> +	}
> +
> +	msleep(120);
> +
> +	ret = mipi_dsi_dcs_enter_sleep_mode(ctx->link);
> +	if (ret < 0) {
> +		DRM_DEV_ERROR(panel->dev, "enter_sleep cmd failed ret = %d\n",
> +			      ret);
> +	}
> +
> +	/* Would call panel_power_off() */
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		ret = regulator_set_load(ctx->supplies[i].consumer,
> +					 regulator_disable_loads[i]);
> +		if (ret) {
> +			DRM_DEV_ERROR(panel->dev,
> +				      "regulator_set_load failed %d\n", ret);
> +			return ret;
> +		}
> +	}
> +
> +	ctx->prepared = false;
> +
> +	return ret;
> +}
> +
> +static int lg_panel_prepare(struct drm_panel *panel)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	int err, i;
> +
> +	if (ctx->prepared)
> +		return 0;
> +
> +	/* Would call panel_reset() */
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
> +		err = regulator_set_load(ctx->supplies[i].consumer,
> +					 regulator_enable_loads[i]);
> +		if (err)
> +			return err;
> +	}
> +
> +	err = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	if (err < 0)
> +		return err;
> +
> +	usleep_range(9000, 10000);
> +
> +	err = mipi_dsi_dcs_write(ctx->link, MIPI_DCS_SET_GAMMA_CURVE,
> +				 (u8[]){ 0x02 }, 1);
> +	if (err < 0) {
> +		DRM_DEV_ERROR(panel->dev, "failed to set gamma curve: %d\n",
> +			      err);
> +		goto poweroff;
> +	}
> +
> +	err = mipi_dsi_dcs_set_tear_on(ctx->link,
> +				       MIPI_DSI_DCS_TEAR_MODE_VBLANK);
> +	if (err < 0) {
> +		DRM_DEV_ERROR(panel->dev, "failed to set tear on: %d\n", err);
> +		goto poweroff;
> +	}
> +
> +	err = send_mipi_cmds(panel, &lg_sw43408_on_cmds_1[0]);
> +
> +	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(ctx->link);
> +	if (err < 0) {
> +		DRM_DEV_ERROR(panel->dev, "failed to exit sleep mode: %d\n",
> +			      err);
> +		goto poweroff;
> +	}
> +
> +	msleep(135);
> +
> +	err = mipi_dsi_dcs_write(ctx->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;
> +	}
> +
> +	err = send_mipi_cmds(panel, &lg_sw43408_on_cmds_2[0]);
> +
> +	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(ctx->link);
> +	if (err < 0) {
> +		DRM_DEV_ERROR(panel->dev, "failed to Set Display ON: %d\n",
> +			      err);
> +		goto poweroff;
> +	}
> +
> +	msleep(120);
> +
> +	ctx->prepared = true;
> +
> +	return 0;
> +
> +poweroff:
> +	gpiod_set_value(ctx->reset_gpio, 1);
> +	regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
> +	return err;
> +}
> +
> +static int lg_panel_enable(struct drm_panel *panel)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	struct drm_dsc_picture_parameter_set pps;
> +	int ret;
> +
> +	if (ctx->enabled)
> +		return 0;
> +
> +	ret = backlight_enable(ctx->backlight);
> +	if (ret) {
> +		DRM_DEV_ERROR(panel->dev, "Failed to enable backlight %d\n",
> +			      ret);
> +		return ret;
> +	}
> +
> +	if (!panel->dsc) {
> +		DRM_DEV_ERROR(panel->dev, "Can't find DSC\n");
> +		return -ENODEV;
> +	}
> +
> +	drm_dsc_pps_payload_pack(&pps, panel->dsc);
> +
> +	ctx->enabled = true;
> +
> +	return 0;
> +}
> +
> +static int lg_panel_get_modes(struct drm_panel *panel,
> +			      struct drm_connector *connector)
> +{
> +	struct sw43408_panel *ctx = to_panel_info(panel);
> +	const struct drm_display_mode *m = ctx->mode;
> +	struct drm_display_mode *mode;
> +
> +	mode = drm_mode_duplicate(connector->dev, m);
> +	if (!mode) {
> +		DRM_DEV_ERROR(panel->dev, "failed to add mode %ux%u\n",
> +			      m->hdisplay, m->vdisplay);
> +		return -ENOMEM;
> +	}
> +
> +	connector->display_info.width_mm = m->width_mm;
> +	connector->display_info.height_mm = m->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 mipi_dsi_device *dsi = bl_get_data(bl);
> +	int ret = 0;
> +	uint16_t brightness;
> +
> +	brightness = (uint16_t)backlight_get_brightness(bl);
> +	/* Brightness is sent in big-endian */
> +	brightness = cpu_to_be16(brightness);
> +
> +	ret = mipi_dsi_dcs_set_display_brightness(dsi, brightness);
> +	return ret;
> +}
> +
> +static int lg_panel_backlight_get_brightness(struct backlight_device *bl)
> +{
> +	struct mipi_dsi_device *dsi = bl_get_data(bl);
> +	int ret = 0;
> +	u16 brightness = 0;
> +
> +	ret = mipi_dsi_dcs_get_display_brightness(dsi, &brightness);
> +	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 sw43408_panel *ctx)
> +{
> +	struct device *dev = &ctx->link->dev;
> +	const struct backlight_properties props = {
> +		.type = BACKLIGHT_PLATFORM,
> +		.brightness = 255,
> +		.max_brightness = 255,
> +	};
> +
> +	ctx->backlight = devm_backlight_device_register(dev, dev_name(dev), dev,
> +							ctx->link,
> +							&lg_panel_backlight_ops,
> +							&props);
> +
> +	if (IS_ERR(ctx->backlight))
> +		return dev_err_probe(dev, PTR_ERR(ctx->backlight),
> +				     "Failed to create backlight\n");
> +
> +	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 drm_display_mode sw43408_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,
> +
> +	.width_mm = 62,
> +	.height_mm = 124,
> +
> +	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
> +};
> +
> +static const struct of_device_id panel_of_match[] = {
> +	{ .compatible = "lg,sw43408", .data = &sw43408_default_mode },
> +	{ /* sentinel */ }
> +};
> +MODULE_DEVICE_TABLE(of, panel_of_match);
> +
> +static int panel_add(struct sw43408_panel *ctx)
> +{
> +	struct device *dev = &ctx->link->dev;
> +	int i, ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++)
> +		ctx->supplies[i].supply = regulator_names[i];
> +
> +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ctx->supplies),
> +				      ctx->supplies);
> +	if (ret < 0)
> +		return ret;
> +
> +	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(ctx->reset_gpio)) {
> +		DRM_DEV_ERROR(dev, "cannot get reset gpio %ld\n",
> +			      PTR_ERR(ctx->reset_gpio));
> +		return PTR_ERR(ctx->reset_gpio);
> +	}
> +
> +	ret = lg_panel_backlight_init(ctx);
> +	if (ret < 0)
> +		return ret;
> +
> +	drm_panel_init(&ctx->base, dev, &panel_funcs, DRM_MODE_CONNECTOR_DSI);
> +
> +	drm_panel_add(&ctx->base);
> +	return ret;
> +}
> +
> +static int panel_probe(struct mipi_dsi_device *dsi)
> +{
> +	struct sw43408_panel *ctx;
> +	struct drm_dsc_config *dsc;
> +	int err;
> +
> +	ctx = devm_kzalloc(&dsi->dev, sizeof(*ctx), GFP_KERNEL);
> +	if (!ctx)
> +		return -ENOMEM;
> +
> +	ctx->mode = of_device_get_match_data(&dsi->dev);
> +	dsi->mode_flags = MIPI_DSI_MODE_LPM;
> +	dsi->format = MIPI_DSI_FMT_RGB888;
> +	dsi->lanes = 4;
> +
> +	ctx->link = dsi;
> +	mipi_dsi_set_drvdata(dsi, ctx);
> +
> +	err = panel_add(ctx);
> +	if (err < 0)
> +		return err;
> +
> +	/* The panel is DSC panel only, set the dsc params */
> +	dsc = devm_kzalloc(&dsi->dev, sizeof(*dsc), GFP_KERNEL);
> +	if (!dsc)
> +		return -ENOMEM;
> +
> +	dsc->dsc_version_major = 0x1;
> +	dsc->dsc_version_minor = 0x1;
> +
> +	dsc->slice_height = 16;
> +	dsc->slice_width = 540;
> +	dsc->slice_count = 1;
> +	dsc->bits_per_component = 8;
> +	dsc->bits_per_pixel = 8;

Note that this field holds 4 fractional bits, this should be 8 << 4.

That's what drm_dsc_pps_payload_pack() expects and returns, but not what
the DSC implementation in DSI nor DPU1 expects until this lands:

https://lore.kernel.org/linux-arm-msm/20221001190807.358691-1-marijn.suijten@somainline.org/

- Marijn

> +	dsc->block_pred_enable = true;
> +
> +	ctx->base.dsc = dsc;
> +
> +	return mipi_dsi_attach(dsi);
> +}
> +
> +static int panel_remove(struct mipi_dsi_device *dsi)
> +{
> +	struct sw43408_panel *ctx = mipi_dsi_get_drvdata(dsi);
> +	int err;
> +
> +	err = lg_panel_unprepare(&ctx->base);
> +	if (err < 0)
> +		DRM_DEV_ERROR(&dsi->dev, "failed to unprepare panel: %d\n",
> +			      err);
> +
> +	err = lg_panel_disable(&ctx->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);
> +
> +	if (ctx->base.dev)
> +		drm_panel_remove(&ctx->base);
> +
> +	return 0;
> +}
> +
> +static struct mipi_dsi_driver panel_driver = {
> +	.driver = {
> +		.name = "panel-lg-sw43408",
> +		.of_match_table = panel_of_match,
> +	},
> +	.probe = panel_probe,
> +	.remove = panel_remove,
> +};
> +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");
> -- 
> 2.36.1
>
diff mbox series

Patch

diff --git a/MAINTAINERS b/MAINTAINERS
index f679152bdbad..8a2b954ad140 100644
--- a/MAINTAINERS
+++ b/MAINTAINERS
@@ -6376,6 +6376,14 @@  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>
+M:	Caleb Connolly <caleb@connolly.tech>
+S:	Maintained
+T:	git git://anongit.freedesktop.org/drm/drm-misc
+F:	Documentation/devicetree/bindings/display/panel/lg,sw43408-panel.txt
+F:	drivers/gpu/drm/panel/panel-lg-sw43408.c
+
 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 38799effd00a..706b112794b9 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -256,6 +256,17 @@  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 42a7ab54234b..ba26a69b74e7 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -25,6 +25,7 @@  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-$(CONFIG_DRM_PANEL_NEWVISION_NV3052C) += panel-newvision-nv3052c.o
 obj-$(CONFIG_DRM_PANEL_NOVATEK_NT35510) += panel-novatek-nt35510.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..c7b8ec7b970d
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-lg-sw43408.c
@@ -0,0 +1,586 @@ 
+// 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/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 <drm/display/drm_dsc.h>
+#include <drm/display/drm_dsc_helper.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",
+};
+
+static const unsigned long regulator_enable_loads[] = {
+	62000,
+	857000,
+};
+
+static const unsigned long regulator_disable_loads[] = {
+	80,
+	0,
+};
+
+struct sw43408_panel {
+	struct drm_panel base;
+	struct mipi_dsi_device *link;
+
+	const struct drm_display_mode *mode;
+	struct backlight_device *backlight;
+
+	struct regulator_bulk_data supplies[ARRAY_SIZE(regulator_names)];
+
+	struct gpio_desc *reset_gpio;
+
+	bool prepared;
+	bool enabled;
+};
+
+static const struct panel_cmd lg_sw43408_on_cmds_1[] = {
+	_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 inline struct sw43408_panel *to_panel_info(struct drm_panel *panel)
+{
+	return container_of(panel, struct sw43408_panel, base);
+}
+
+/*
+ * Currently unable to bring up the panel after resetting, must be missing
+ * some init commands somewhere.
+ */
+static __always_unused int panel_reset(struct sw43408_panel *ctx)
+{
+	int ret = 0, i;
+
+	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
+		ret = regulator_set_load(ctx->supplies[i].consumer,
+					 regulator_enable_loads[i]);
+		if (ret)
+			return ret;
+	}
+
+	ret = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+	if (ret < 0)
+		return ret;
+
+	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
+		ret = regulator_set_load(ctx->supplies[i].consumer,
+					 regulator_disable_loads[i]);
+		if (ret) {
+			DRM_DEV_ERROR(ctx->base.dev,
+				      "regulator_set_load failed %d\n", ret);
+			return ret;
+		}
+	}
+
+	ret = regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+	if (ret < 0)
+		return ret;
+
+	gpiod_set_value(ctx->reset_gpio, 0);
+	usleep_range(9000, 10000);
+	gpiod_set_value(ctx->reset_gpio, 1);
+	usleep_range(1000, 2000);
+	gpiod_set_value(ctx->reset_gpio, 0);
+	usleep_range(9000, 10000);
+
+	return 0;
+}
+
+static int send_mipi_cmds(struct drm_panel *panel, const struct panel_cmd *cmds)
+{
+	struct sw43408_panel *ctx = 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(ctx->link, cmd->data[1], NULL,
+						 0);
+		else
+			err = mipi_dsi_dcs_write(ctx->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 lg_panel_disable(struct drm_panel *panel)
+{
+	struct sw43408_panel *ctx = to_panel_info(panel);
+
+	backlight_disable(ctx->backlight);
+	ctx->enabled = false;
+
+	return 0;
+}
+
+/*
+ * We can't currently re-initialise the panel properly after powering off.
+ * This function will be used when this is resolved.
+ */
+static __always_unused int lg_panel_power_off(struct drm_panel *panel)
+{
+	struct sw43408_panel *ctx = to_panel_info(panel);
+	int i, ret = 0;
+
+	gpiod_set_value(ctx->reset_gpio, 1);
+
+	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
+		ret = regulator_set_load(ctx->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(ctx->supplies), ctx->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)
+{
+	struct sw43408_panel *ctx = to_panel_info(panel);
+	int ret, i;
+
+	if (!ctx->prepared)
+		return 0;
+
+	ret = mipi_dsi_dcs_set_display_off(ctx->link);
+	if (ret < 0) {
+		DRM_DEV_ERROR(panel->dev,
+			      "set_display_off cmd failed ret = %d\n", ret);
+	}
+
+	msleep(120);
+
+	ret = mipi_dsi_dcs_enter_sleep_mode(ctx->link);
+	if (ret < 0) {
+		DRM_DEV_ERROR(panel->dev, "enter_sleep cmd failed ret = %d\n",
+			      ret);
+	}
+
+	/* Would call panel_power_off() */
+
+	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
+		ret = regulator_set_load(ctx->supplies[i].consumer,
+					 regulator_disable_loads[i]);
+		if (ret) {
+			DRM_DEV_ERROR(panel->dev,
+				      "regulator_set_load failed %d\n", ret);
+			return ret;
+		}
+	}
+
+	ctx->prepared = false;
+
+	return ret;
+}
+
+static int lg_panel_prepare(struct drm_panel *panel)
+{
+	struct sw43408_panel *ctx = to_panel_info(panel);
+	int err, i;
+
+	if (ctx->prepared)
+		return 0;
+
+	/* Would call panel_reset() */
+
+	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++) {
+		err = regulator_set_load(ctx->supplies[i].consumer,
+					 regulator_enable_loads[i]);
+		if (err)
+			return err;
+	}
+
+	err = regulator_bulk_enable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+	if (err < 0)
+		return err;
+
+	usleep_range(9000, 10000);
+
+	err = mipi_dsi_dcs_write(ctx->link, MIPI_DCS_SET_GAMMA_CURVE,
+				 (u8[]){ 0x02 }, 1);
+	if (err < 0) {
+		DRM_DEV_ERROR(panel->dev, "failed to set gamma curve: %d\n",
+			      err);
+		goto poweroff;
+	}
+
+	err = mipi_dsi_dcs_set_tear_on(ctx->link,
+				       MIPI_DSI_DCS_TEAR_MODE_VBLANK);
+	if (err < 0) {
+		DRM_DEV_ERROR(panel->dev, "failed to set tear on: %d\n", err);
+		goto poweroff;
+	}
+
+	err = send_mipi_cmds(panel, &lg_sw43408_on_cmds_1[0]);
+
+	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(ctx->link);
+	if (err < 0) {
+		DRM_DEV_ERROR(panel->dev, "failed to exit sleep mode: %d\n",
+			      err);
+		goto poweroff;
+	}
+
+	msleep(135);
+
+	err = mipi_dsi_dcs_write(ctx->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;
+	}
+
+	err = send_mipi_cmds(panel, &lg_sw43408_on_cmds_2[0]);
+
+	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(ctx->link);
+	if (err < 0) {
+		DRM_DEV_ERROR(panel->dev, "failed to Set Display ON: %d\n",
+			      err);
+		goto poweroff;
+	}
+
+	msleep(120);
+
+	ctx->prepared = true;
+
+	return 0;
+
+poweroff:
+	gpiod_set_value(ctx->reset_gpio, 1);
+	regulator_bulk_disable(ARRAY_SIZE(ctx->supplies), ctx->supplies);
+	return err;
+}
+
+static int lg_panel_enable(struct drm_panel *panel)
+{
+	struct sw43408_panel *ctx = to_panel_info(panel);
+	struct drm_dsc_picture_parameter_set pps;
+	int ret;
+
+	if (ctx->enabled)
+		return 0;
+
+	ret = backlight_enable(ctx->backlight);
+	if (ret) {
+		DRM_DEV_ERROR(panel->dev, "Failed to enable backlight %d\n",
+			      ret);
+		return ret;
+	}
+
+	if (!panel->dsc) {
+		DRM_DEV_ERROR(panel->dev, "Can't find DSC\n");
+		return -ENODEV;
+	}
+
+	drm_dsc_pps_payload_pack(&pps, panel->dsc);
+
+	ctx->enabled = true;
+
+	return 0;
+}
+
+static int lg_panel_get_modes(struct drm_panel *panel,
+			      struct drm_connector *connector)
+{
+	struct sw43408_panel *ctx = to_panel_info(panel);
+	const struct drm_display_mode *m = ctx->mode;
+	struct drm_display_mode *mode;
+
+	mode = drm_mode_duplicate(connector->dev, m);
+	if (!mode) {
+		DRM_DEV_ERROR(panel->dev, "failed to add mode %ux%u\n",
+			      m->hdisplay, m->vdisplay);
+		return -ENOMEM;
+	}
+
+	connector->display_info.width_mm = m->width_mm;
+	connector->display_info.height_mm = m->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 mipi_dsi_device *dsi = bl_get_data(bl);
+	int ret = 0;
+	uint16_t brightness;
+
+	brightness = (uint16_t)backlight_get_brightness(bl);
+	/* Brightness is sent in big-endian */
+	brightness = cpu_to_be16(brightness);
+
+	ret = mipi_dsi_dcs_set_display_brightness(dsi, brightness);
+	return ret;
+}
+
+static int lg_panel_backlight_get_brightness(struct backlight_device *bl)
+{
+	struct mipi_dsi_device *dsi = bl_get_data(bl);
+	int ret = 0;
+	u16 brightness = 0;
+
+	ret = mipi_dsi_dcs_get_display_brightness(dsi, &brightness);
+	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 sw43408_panel *ctx)
+{
+	struct device *dev = &ctx->link->dev;
+	const struct backlight_properties props = {
+		.type = BACKLIGHT_PLATFORM,
+		.brightness = 255,
+		.max_brightness = 255,
+	};
+
+	ctx->backlight = devm_backlight_device_register(dev, dev_name(dev), dev,
+							ctx->link,
+							&lg_panel_backlight_ops,
+							&props);
+
+	if (IS_ERR(ctx->backlight))
+		return dev_err_probe(dev, PTR_ERR(ctx->backlight),
+				     "Failed to create backlight\n");
+
+	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 drm_display_mode sw43408_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,
+
+	.width_mm = 62,
+	.height_mm = 124,
+
+	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
+};
+
+static const struct of_device_id panel_of_match[] = {
+	{ .compatible = "lg,sw43408", .data = &sw43408_default_mode },
+	{ /* sentinel */ }
+};
+MODULE_DEVICE_TABLE(of, panel_of_match);
+
+static int panel_add(struct sw43408_panel *ctx)
+{
+	struct device *dev = &ctx->link->dev;
+	int i, ret;
+
+	for (i = 0; i < ARRAY_SIZE(ctx->supplies); i++)
+		ctx->supplies[i].supply = regulator_names[i];
+
+	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(ctx->supplies),
+				      ctx->supplies);
+	if (ret < 0)
+		return ret;
+
+	ctx->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
+	if (IS_ERR(ctx->reset_gpio)) {
+		DRM_DEV_ERROR(dev, "cannot get reset gpio %ld\n",
+			      PTR_ERR(ctx->reset_gpio));
+		return PTR_ERR(ctx->reset_gpio);
+	}
+
+	ret = lg_panel_backlight_init(ctx);
+	if (ret < 0)
+		return ret;
+
+	drm_panel_init(&ctx->base, dev, &panel_funcs, DRM_MODE_CONNECTOR_DSI);
+
+	drm_panel_add(&ctx->base);
+	return ret;
+}
+
+static int panel_probe(struct mipi_dsi_device *dsi)
+{
+	struct sw43408_panel *ctx;
+	struct drm_dsc_config *dsc;
+	int err;
+
+	ctx = devm_kzalloc(&dsi->dev, sizeof(*ctx), GFP_KERNEL);
+	if (!ctx)
+		return -ENOMEM;
+
+	ctx->mode = of_device_get_match_data(&dsi->dev);
+	dsi->mode_flags = MIPI_DSI_MODE_LPM;
+	dsi->format = MIPI_DSI_FMT_RGB888;
+	dsi->lanes = 4;
+
+	ctx->link = dsi;
+	mipi_dsi_set_drvdata(dsi, ctx);
+
+	err = panel_add(ctx);
+	if (err < 0)
+		return err;
+
+	/* The panel is DSC panel only, set the dsc params */
+	dsc = devm_kzalloc(&dsi->dev, sizeof(*dsc), GFP_KERNEL);
+	if (!dsc)
+		return -ENOMEM;
+
+	dsc->dsc_version_major = 0x1;
+	dsc->dsc_version_minor = 0x1;
+
+	dsc->slice_height = 16;
+	dsc->slice_width = 540;
+	dsc->slice_count = 1;
+	dsc->bits_per_component = 8;
+	dsc->bits_per_pixel = 8;
+	dsc->block_pred_enable = true;
+
+	ctx->base.dsc = dsc;
+
+	return mipi_dsi_attach(dsi);
+}
+
+static int panel_remove(struct mipi_dsi_device *dsi)
+{
+	struct sw43408_panel *ctx = mipi_dsi_get_drvdata(dsi);
+	int err;
+
+	err = lg_panel_unprepare(&ctx->base);
+	if (err < 0)
+		DRM_DEV_ERROR(&dsi->dev, "failed to unprepare panel: %d\n",
+			      err);
+
+	err = lg_panel_disable(&ctx->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);
+
+	if (ctx->base.dev)
+		drm_panel_remove(&ctx->base);
+
+	return 0;
+}
+
+static struct mipi_dsi_driver panel_driver = {
+	.driver = {
+		.name = "panel-lg-sw43408",
+		.of_match_table = panel_of_match,
+	},
+	.probe = panel_probe,
+	.remove = panel_remove,
+};
+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");