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Date:   Sat, 9 Jul 2022 11:30:30 +0200
From:   Sam Ravnborg <sam@ravnborg.org>
To:     MollySophia <mollysophia379@gmail.com>
Cc:     Thierry Reding <thierry.reding@gmail.com>,
        David Airlie <airlied@linux.ie>,
        Daniel Vetter <daniel@ffwll.ch>,
        Rob Herring <robh+dt@kernel.org>,
        Krzysztof Kozlowski <krzysztof.kozlowski+dt@linaro.org>,
        dri-devel@lists.freedesktop.org, devicetree@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        ~postmarketos/upstreaming@lists.sr.ht, phone-devel@vger.kernel.org,
        linux-arm-msm@vger.kernel.org
Subject: Re: [PATCH] drm: panel: Add novatek nt35596s panel driver
Message-ID: <YslKtrZa0QdRsBLD@ravnborg.org>
References: <20220708021824.9167-1-mollysophia379@gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20220708021824.9167-1-mollysophia379@gmail.com>
Precedence: bulk

Hi Molly,

Thanks for submitting this driver.
A few comments follows - the most relevant is the error handling when
unprepare/disable.

Please take a look and re-submit.

	Sam

On Fri, Jul 08, 2022 at 10:18:23AM +0800, MollySophia wrote:
> Novatek NT35596s is a generic DSI IC that drives command and video mode
> panels. Add the driver for it. Currently add support for the LCD panel
> from JDI connected with this IC, as found on Xiaomi Mi Mix2s phones.


> 
> Signed-off-by: MollySophia <mollysophia379@gmail.com>
> ---
>  drivers/gpu/drm/panel/Kconfig                 |   9 +
>  drivers/gpu/drm/panel/Makefile                |   1 +
>  .../gpu/drm/panel/panel-jdi-fhd-nt35596s.c    | 464 ++++++++++++++++++
>  3 files changed, 474 insertions(+)
>  create mode 100644 drivers/gpu/drm/panel/panel-jdi-fhd-nt35596s.c
> 
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index d5176f75248f..a54389c107bc 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -231,6 +231,15 @@ config DRM_PANEL_JDI_R63452
>  	  Say Y here if you want to enable support for the JDI R63452
>  	  DSI command mode panel as found in Xiaomi Mi 5 Devices.
> 
> +config DRM_PANEL_JDI_NT35596S
> +	tristate "JDI NT35596S Full HD DSI 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 the JDI NT35596S
> +	  DSI video mode panel as found in Xiaomi Mi Mix2s Devices.
> +
Alphabetic order is preferred, so it comes before DRM_PANEL_JDI_R63452

>  config DRM_PANEL_KHADAS_TS050
>  	tristate "Khadas TS050 panel"
>  	depends on OF
> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> index ef89dada021d..40db5e6dcbf5 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -21,6 +21,7 @@ obj-$(CONFIG_DRM_PANEL_INNOLUX_P079ZCA) += panel-innolux-p079zca.o
>  obj-$(CONFIG_DRM_PANEL_INNOLUX_TD4328) += panel-innolux-td4328.o
>  obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
>  obj-$(CONFIG_DRM_PANEL_JDI_R63452) += panel-jdi-fhd-r63452.o
> +obj-$(CONFIG_DRM_PANEL_JDI_NT35596S) += panel-jdi-fhd-nt35596s.o
Alphabetic order is preferred, so again before CONFIG_DRM_PANEL_JDI_R63452

>  obj-$(CONFIG_DRM_PANEL_KHADAS_TS050) += panel-khadas-ts050.o
>  obj-$(CONFIG_DRM_PANEL_KINGDISPLAY_KD097D04) += panel-kingdisplay-kd097d04.o
>  obj-$(CONFIG_DRM_PANEL_LEADTEK_LTK050H3146W) += panel-leadtek-ltk050h3146w.o
> diff --git a/drivers/gpu/drm/panel/panel-jdi-fhd-nt35596s.c b/drivers/gpu/drm/panel/panel-jdi-fhd-nt35596s.c
> new file mode 100644
> index 000000000000..0793bcd872e2
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-jdi-fhd-nt35596s.c
> @@ -0,0 +1,464 @@
> +// SPDX-License-Identifier: GPL-2.0-only
> +/*
> + * Copyright (c) 2022 Molly Sophia <mollysophia379@gmail.com>
> + *
> + */
> +
> +#include <linux/delay.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/of_device.h>
> +#include <linux/regulator/consumer.h>
> +#include <linux/swab.h>
> +#include <linux/backlight.h>
> +
> +#include <video/mipi_display.h>
> +
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_modes.h>
> +#include <drm/drm_panel.h>
> +
> +struct nt35596s_panel_cmd {
> +	const char data[2];
> +};
> +
> +static const char *const nt35596s_regulator_names[] = {
> +	"vddio",
> +	"vddpos",
> +	"vddneg",
> +};
> +
> +static const unsigned long nt35596s_regulator_enable_loads[] = { 62000, 100000,
> +								 100000 };
> +
> +struct nt35596s_panel_desc {
> +	const struct drm_display_mode *display_mode;
> +	const char *panel_name;
panel_name is not used - drop it.
> +
> +	unsigned int width_mm;
> +	unsigned int height_mm;
> +
> +	unsigned long mode_flags;
> +	enum mipi_dsi_pixel_format format;
> +	unsigned int lanes;
> +
> +	unsigned int num_on_cmds;
> +	const struct nt35596s_panel_cmd *on_cmds;
> +};
> +
> +struct nt35596s_panel {
> +	struct drm_panel panel;
> +	struct mipi_dsi_device *dsi;
> +	const struct nt35596s_panel_desc *desc;
> +
> +	struct regulator_bulk_data
> +		supplies[ARRAY_SIZE(nt35596s_regulator_names)];
> +
> +	struct gpio_desc *reset_gpio;
> +	bool prepared;
> +};
> +
> +static inline struct nt35596s_panel *to_nt35596s_panel(struct drm_panel *panel)
> +{
> +	return container_of(panel, struct nt35596s_panel, panel);
> +}
> +
> +static int nt35596s_send_cmds(struct drm_panel *panel,
> +			      const struct nt35596s_panel_cmd *cmds, int num)
> +{
> +	struct nt35596s_panel *pinfo = to_nt35596s_panel(panel);
> +	unsigned int i;
> +	int err;
> +
> +	for (i = 0; i < num; i++) {
> +		const struct nt35596s_panel_cmd *cmd = &cmds[i];
> +
> +		err = mipi_dsi_dcs_write(pinfo->dsi, cmd->data[0],
> +					 cmd->data + 1, 1);
> +
> +		if (err < 0)
> +			return err;
> +	}
> +
> +	return 0;
> +}
> +
> +static int nt35596s_panel_power_off(struct drm_panel *panel)
> +{
> +	struct nt35596s_panel *pinfo = to_nt35596s_panel(panel);
> +	int ret = 0;
> +
> +	gpiod_set_value(pinfo->reset_gpio, 1);
> +
> +	ret = regulator_bulk_disable(ARRAY_SIZE(pinfo->supplies),
> +				     pinfo->supplies);
> +	if (ret)
> +		dev_err(panel->dev, "regulator_bulk_disable failed %d\n", ret);
> +
> +	return ret;
> +}
> +
> +static int nt35596s_panel_unprepare(struct drm_panel *panel)
> +{
> +	struct nt35596s_panel *pinfo = to_nt35596s_panel(panel);
> +	int ret;
> +
> +	if (!pinfo->prepared)
> +		return 0;
> +
> +	ret = mipi_dsi_dcs_set_display_off(pinfo->dsi);
> +	if (ret < 0)
> +		dev_err(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->dsi);
> +	if (ret < 0)
> +		dev_err(panel->dev, "enter_sleep cmd failed ret = %d\n", ret);
> +
> +	/* 0x46 = 70ms delay */
> +	msleep(70);
> +
> +	ret = nt35596s_panel_power_off(panel);
> +	if (ret < 0)
> +		dev_err(panel->dev, "power_off failed ret = %d\n", ret);
Two error messages are written here. One in nt35596s_panel_power_off()
and one here. It would be better to keep all dev_err in the caller and
drop it from nt35596s_panel_power_off().


> +
> +	pinfo->prepared = false;
> +
> +	return ret;
> +}
> +
> +static int nt35596s_panel_power_on(struct nt35596s_panel *pinfo)
> +{
> +	int ret;
> +
> +	ret = regulator_bulk_enable(ARRAY_SIZE(pinfo->supplies),
> +				    pinfo->supplies);
> +	if (ret < 0)
> +		return ret;
No error message here - so the off and on variant are not the same.
If the code fails to power on then consider to apply reset here - so
there is no need to think about reset in the prepare function.

> +
> +	gpiod_set_value(pinfo->reset_gpio, 1);
> +	msleep(200);
> +	gpiod_set_value(pinfo->reset_gpio, 0);
> +	msleep(200);
> +
> +	return 0;
> +}
> +
> +static int nt35596s_panel_prepare(struct drm_panel *panel)
> +{
> +	struct nt35596s_panel *pinfo = to_nt35596s_panel(panel);
> +	int err;
> +
> +	if (pinfo->prepared)
> +		return 0;
> +
> +	err = nt35596s_panel_power_on(pinfo);
> +	if (err < 0)
> +		goto poweroff;
Here it would have been nice to tell that power on failed.
If nt35596s_panel_power_on() do the reset handling the function can exit
here.

> +
> +	err = nt35596s_send_cmds(panel, pinfo->desc->on_cmds,
> +				 pinfo->desc->num_on_cmds);
> +
> +	if (err < 0) {
> +		dev_err(panel->dev, "failed to send DCS Init Code: %d\n", err);
> +		goto poweroff;
> +	}
> +
> +	err = mipi_dsi_dcs_exit_sleep_mode(pinfo->dsi);
> +	if (err < 0) {
> +		dev_err(panel->dev, "failed to exit sleep mode: %d\n", err);
> +		goto poweroff;
> +	}
> +
> +	/* 0x46 = 70 ms delay */
> +	msleep(70);
> +
> +	err = mipi_dsi_dcs_set_display_on(pinfo->dsi);
> +	if (err < 0) {
> +		dev_err(panel->dev, "failed to Set Display ON: %d\n", err);
> +		goto poweroff;
> +	}
> +
> +	msleep(120);
> +
> +	pinfo->prepared = true;
> +
> +	return 0;
> +
> +poweroff:
> +	gpiod_set_value(pinfo->reset_gpio, 0);
Here it would be better to do what the label says and call the power_off
function. Right now the display may be left powered on but reset.

> +	return err;
> +}
> +
> +static int nt35596s_panel_get_modes(struct drm_panel *panel,
> +				    struct drm_connector *connector)
> +{
> +	struct nt35596s_panel *pinfo = to_nt35596s_panel(panel);
> +	const struct drm_display_mode *m = pinfo->desc->display_mode;
> +	struct drm_display_mode *mode;
> +
> +	mode = drm_mode_duplicate(connector->dev, m);
> +	if (!mode) {
> +		dev_err(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 const struct drm_panel_funcs panel_funcs = {
> +	.prepare = nt35596s_panel_prepare,
> +	.unprepare = nt35596s_panel_unprepare,
> +	.get_modes = nt35596s_panel_get_modes,
> +};
> +
> +static const struct nt35596s_panel_cmd jdi_fhd_video_on_cmds[] = {
> +	{ .data = { 0xff, 0x24 } }, { .data = { 0x9d, 0x34 } },
> +	{ .data = { 0xfb, 0x01 } }, { .data = { 0xc4, 0x25 } },
> +	{ .data = { 0xd1, 0x08 } }, { .data = { 0xd2, 0x84 } },
> +	{ .data = { 0xff, 0x26 } }, { .data = { 0xfb, 0x01 } },
> +	{ .data = { 0x03, 0x1c } }, { .data = { 0x3b, 0x08 } },
> +	{ .data = { 0x6b, 0x08 } }, { .data = { 0x97, 0x08 } },
> +	{ .data = { 0xc5, 0x08 } }, { .data = { 0xfb, 0x01 } },
> +	{ .data = { 0xff, 0x23 } }, { .data = { 0xfb, 0x01 } },
> +	{ .data = { 0x01, 0x84 } }, { .data = { 0x05, 0x2d } },
> +	{ .data = { 0x06, 0x00 } }, { .data = { 0x33, 0x07 } },
> +	{ .data = { 0x21, 0xee } }, { .data = { 0x22, 0xed } },
> +	{ .data = { 0x23, 0xea } }, { .data = { 0x24, 0xe8 } },
> +	{ .data = { 0x25, 0xe5 } }, { .data = { 0x26, 0xe2 } },
> +	{ .data = { 0x27, 0xde } }, { .data = { 0x28, 0xbb } },
> +	{ .data = { 0x29, 0x87 } }, { .data = { 0x2a, 0x77 } },
> +	{ .data = { 0x32, 0x0c } }, { .data = { 0x13, 0x3f } },
> +	{ .data = { 0x14, 0x34 } }, { .data = { 0x15, 0x2a } },
> +	{ .data = { 0x16, 0x25 } }, { .data = { 0x17, 0x9d } },
> +	{ .data = { 0x18, 0x9a } }, { .data = { 0x19, 0x97 } },
> +	{ .data = { 0x1a, 0x94 } }, { .data = { 0x1b, 0x91 } },
> +	{ .data = { 0x1c, 0x8e } }, { .data = { 0x1d, 0x8b } },
> +	{ .data = { 0x1e, 0x89 } }, { .data = { 0x1f, 0x86 } },
> +	{ .data = { 0x20, 0x83 } }, { .data = { 0xff, 0x22 } },
> +	{ .data = { 0x00, 0x0a } }, { .data = { 0x01, 0x43 } },
> +	{ .data = { 0x02, 0x5b } }, { .data = { 0x03, 0x6a } },
> +	{ .data = { 0x04, 0x7a } }, { .data = { 0x05, 0x82 } },
> +	{ .data = { 0x06, 0x85 } }, { .data = { 0x07, 0x80 } },
> +	{ .data = { 0x08, 0x7c } }, { .data = { 0x09, 0x7c } },
> +	{ .data = { 0x0a, 0x74 } }, { .data = { 0x0b, 0x71 } },
> +	{ .data = { 0x0c, 0x6e } }, { .data = { 0x0d, 0x68 } },
> +	{ .data = { 0x0e, 0x65 } }, { .data = { 0x0f, 0x5c } },
> +	{ .data = { 0x10, 0x32 } }, { .data = { 0x11, 0x18 } },
> +	{ .data = { 0x12, 0x00 } }, { .data = { 0x13, 0x00 } },
> +	{ .data = { 0x1a, 0x00 } }, { .data = { 0x1b, 0x00 } },
> +	{ .data = { 0x1c, 0x00 } }, { .data = { 0x1d, 0x00 } },
> +	{ .data = { 0x1e, 0x00 } }, { .data = { 0x1f, 0x00 } },
> +	{ .data = { 0x20, 0x00 } }, { .data = { 0x21, 0x00 } },
> +	{ .data = { 0x22, 0x00 } }, { .data = { 0x23, 0x00 } },
> +	{ .data = { 0x24, 0x00 } }, { .data = { 0x25, 0x00 } },
> +	{ .data = { 0x26, 0x00 } }, { .data = { 0x27, 0x00 } },
> +	{ .data = { 0x28, 0x00 } }, { .data = { 0x29, 0x00 } },
> +	{ .data = { 0x2a, 0x00 } }, { .data = { 0x2b, 0x00 } },
> +	{ .data = { 0x2f, 0x00 } }, { .data = { 0x30, 0x00 } },
> +	{ .data = { 0x31, 0x00 } }, { .data = { 0x32, 0x0c } },
> +	{ .data = { 0x33, 0x0c } }, { .data = { 0x34, 0x0c } },
> +	{ .data = { 0x35, 0x0b } }, { .data = { 0x36, 0x09 } },
> +	{ .data = { 0x37, 0x09 } }, { .data = { 0x38, 0x08 } },
> +	{ .data = { 0x39, 0x05 } }, { .data = { 0x3a, 0x03 } },
> +	{ .data = { 0x3b, 0x00 } }, { .data = { 0x3f, 0x00 } },
> +	{ .data = { 0x40, 0x00 } }, { .data = { 0x41, 0x00 } },
> +	{ .data = { 0x42, 0x00 } }, { .data = { 0x43, 0x00 } },
> +	{ .data = { 0x44, 0x00 } }, { .data = { 0x45, 0x00 } },
> +	{ .data = { 0x46, 0x00 } }, { .data = { 0x47, 0x00 } },
> +	{ .data = { 0x48, 0x00 } }, { .data = { 0x49, 0x03 } },
> +	{ .data = { 0x4a, 0x06 } }, { .data = { 0x4b, 0x07 } },
> +	{ .data = { 0x4c, 0x07 } }, { .data = { 0x53, 0x01 } },
> +	{ .data = { 0x54, 0x01 } }, { .data = { 0x55, 0x89 } },
> +	{ .data = { 0x56, 0x00 } }, { .data = { 0x58, 0x00 } },
> +	{ .data = { 0x68, 0x00 } }, { .data = { 0x84, 0xff } },
> +	{ .data = { 0x85, 0xff } }, { .data = { 0x86, 0x03 } },
> +	{ .data = { 0x87, 0x00 } }, { .data = { 0x88, 0x00 } },
> +	{ .data = { 0xa2, 0x20 } }, { .data = { 0xa9, 0x01 } },
> +	{ .data = { 0xaa, 0x12 } }, { .data = { 0xab, 0x13 } },
> +	{ .data = { 0xac, 0x0a } }, { .data = { 0xad, 0x74 } },
> +	{ .data = { 0xaf, 0x33 } }, { .data = { 0xb0, 0x03 } },
> +	{ .data = { 0xb1, 0x14 } }, { .data = { 0xb2, 0x42 } },
> +	{ .data = { 0xb3, 0x40 } }, { .data = { 0xb4, 0xa5 } },
> +	{ .data = { 0xb6, 0x44 } }, { .data = { 0xb7, 0x04 } },
> +	{ .data = { 0xb8, 0x14 } }, { .data = { 0xb9, 0x42 } },
> +	{ .data = { 0xba, 0x40 } }, { .data = { 0xbb, 0xa5 } },
> +	{ .data = { 0xbd, 0x44 } }, { .data = { 0xbe, 0x04 } },
> +	{ .data = { 0xbf, 0x00 } }, { .data = { 0xc0, 0x75 } },
> +	{ .data = { 0xc1, 0x6a } }, { .data = { 0xc2, 0xa5 } },
> +	{ .data = { 0xc4, 0x22 } }, { .data = { 0xc5, 0x02 } },
> +	{ .data = { 0xc6, 0x00 } }, { .data = { 0xc7, 0x95 } },
> +	{ .data = { 0xc8, 0x8a } }, { .data = { 0xc9, 0xa5 } },
> +	{ .data = { 0xcb, 0x22 } }, { .data = { 0xcc, 0x02 } },
> +	{ .data = { 0xcd, 0x00 } }, { .data = { 0xce, 0xb5 } },
> +	{ .data = { 0xcf, 0xaa } }, { .data = { 0xd0, 0xa5 } },
> +	{ .data = { 0xd2, 0x22 } }, { .data = { 0xd3, 0x02 } },
> +	{ .data = { 0xfb, 0x01 } }, { .data = { 0xff, 0x10 } },
> +	{ .data = { 0x26, 0x02 } }, { .data = { 0x35, 0x00 } },
> +	{ .data = { 0x51, 0xff } }, { .data = { 0x53, 0x24 } },
> +	{ .data = { 0x55, 0x00 } }, { .data = { 0xb0, 0x00 } },
> +};
> +
> +static const struct drm_display_mode jdi_fhd_video_panel_mode = {
> +	.clock = (1080 + 16 + 28 + 40) * (2160 + 7 + 4 + 24) * 60 / 1000,
> +
> +	.hdisplay = 1080,
> +	.hsync_start = 1080 + 16,
> +	.hsync_end = 1080 + 16 + 28,
> +	.htotal = 1080 + 16 + 28 + 40,
> +
> +	.vdisplay = 2160,
> +	.vsync_start = 2160 + 7,
> +	.vsync_end = 2160 + 7 + 4,
> +	.vtotal = 2160 + 7 + 4 + 24,
> +
> +	.type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
> +};
> +
> +static const struct nt35596s_panel_desc jdi_fhd_video_panel_desc = {
> +	.display_mode = &jdi_fhd_video_panel_mode,
> +
> +	.width_mm = 68,
> +	.height_mm = 136,
> +
> +	.mode_flags = MIPI_DSI_MODE_LPM | MIPI_DSI_MODE_VIDEO |
> +		      MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_CLOCK_NON_CONTINUOUS |
> +		      MIPI_DSI_MODE_VIDEO_BURST,
> +	.format = MIPI_DSI_FMT_RGB888,
> +	.lanes = 4,
> +	.on_cmds = jdi_fhd_video_on_cmds,
> +	.num_on_cmds = ARRAY_SIZE(jdi_fhd_video_on_cmds),
> +};
> +
> +static int nt35596s_panel_add(struct nt35596s_panel *pinfo)
> +{
> +	struct device *dev = &pinfo->dsi->dev;
> +	int i, ret;
> +
> +	for (i = 0; i < ARRAY_SIZE(pinfo->supplies); i++)
> +		pinfo->supplies[i].supply = nt35596s_regulator_names[i];
> +
> +	ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(pinfo->supplies),
> +				      pinfo->supplies);
> +	if (ret < 0)
> +		return dev_err_probe(dev, ret, "failed to get regulators\n");
> +
> +	for (i = 0; i < ARRAY_SIZE(pinfo->supplies); i++) {
> +		ret = regulator_set_load(pinfo->supplies[i].consumer,
> +					 nt35596s_regulator_enable_loads[i]);
> +		if (ret)
> +			return dev_err_probe(
> +				dev, ret,
> +				"failed to set regulator enable loads\n");
> +	}
> +
> +	pinfo->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(pinfo->reset_gpio))
> +		return dev_err_probe(dev, PTR_ERR(pinfo->reset_gpio),
> +				     "failed to get reset gpio from DT\n");
> +
> +	drm_panel_init(&pinfo->panel, dev, &panel_funcs,
> +		       DRM_MODE_CONNECTOR_DSI);
> +
> +	ret = drm_panel_of_backlight(&pinfo->panel);
> +	if (ret)
> +		return dev_err_probe(dev, ret, "Failed to get backlight\n");
> +
> +	drm_panel_add(&pinfo->panel);
> +
> +	return 0;
> +}
> +
> +static int nt35596s_panel_probe(struct mipi_dsi_device *dsi)
> +{
> +	struct nt35596s_panel *pinfo;
> +	const struct nt35596s_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->dsi = dsi;
> +
> +	mipi_dsi_set_drvdata(dsi, pinfo);
> +
> +	err = nt35596s_panel_add(pinfo);
> +	if (err < 0)
> +		return err;
> +
> +	err = mipi_dsi_attach(dsi);
> +	if (err < 0) {
> +		drm_panel_remove(&pinfo->panel);
> +		return err;
> +	}
> +
> +	return 0;
> +}
> +
> +static int nt35596s_panel_remove(struct mipi_dsi_device *dsi)
> +{
> +	struct nt35596s_panel *pinfo = mipi_dsi_get_drvdata(dsi);
> +	int err;
> +
> +	err = drm_panel_unprepare(&pinfo->panel);
> +	if (err < 0)
> +		dev_err(&dsi->dev, "failed to unprepare panel: %d\n", err);
> +
> +	err = drm_panel_disable(&pinfo->panel);
> +	if (err < 0)
> +		dev_err(&dsi->dev, "failed to disable panel: %d\n", err);
> +
> +	err = mipi_dsi_detach(dsi);
> +	if (err < 0)
> +		dev_err(&dsi->dev, "failed to detach from DSI host: %d\n", err);
> +
> +	drm_panel_remove(&pinfo->panel);
> +
> +	return 0;
> +}
> +
> +static void nt35596s_panel_shutdown(struct mipi_dsi_device *dsi)
> +{
> +	struct nt35596s_panel *pinfo = mipi_dsi_get_drvdata(dsi);
> +
> +	drm_panel_disable(&pinfo->panel);
> +	drm_panel_unprepare(&pinfo->panel);
> +}
> +
> +static const struct of_device_id nt35596s_panel_of_match[] = {
> +	{ .compatible = "jdi,fhd-nt35596s", .data = &jdi_fhd_video_panel_desc },
> +	{}
> +};
> +MODULE_DEVICE_TABLE(of, nt35596s_panel_of_match);
> +
> +static struct mipi_dsi_driver nt35596s_panel_driver = {
> +	.driver = {
> +		.name = "panel-jdi-fhd-nt35596s",
> +		.of_match_table = nt35596s_panel_of_match,
> +	},
> +	.probe = nt35596s_panel_probe,
> +	.remove = nt35596s_panel_remove,
> +	.shutdown = nt35596s_panel_shutdown,
> +};
> +module_mipi_dsi_driver(nt35596s_panel_driver);
> +
> +MODULE_AUTHOR("Molly Sophia <mollysophia379@gmail.com>");
> +MODULE_DESCRIPTION("DRM driver for JDI FHD nt35596s DSI panel, video mode");
> +MODULE_LICENSE("GPL");
> -- 
> 2.37.0