Re: [PATCH] drm/panel: Add JDI LT070ME05000 WUXGA DSI Panel

From: Archit Taneja <architt@codeaurora.org>
To: Vinay Simha BN <simhavcs@gmail.com>
Cc: Mark Rutland <mark.rutland@arm.com>,
	"open list:OPEN FIRMWARE AND FLATTENED DEVICE TREE BINDINGS" 
	<devicetree@vger.kernel.org>, Pawel Moll <pawel.moll@arm.com>,
	Ian Campbell <ijc+devicetree@hellion.org.uk>,
	"open list:DRM PANEL DRIVERS" <dri-devel@lists.freedesktop.org>,
	open list <linux-kernel@vger.kernel.org>,
	Ralf Baechle <ralf@linux-mips.org>,
	Rob Herring <robh+dt@kernel.org>,
	Jonathan Cameron <jic23@kernel.org>,
	Kumar Gala <galak@codeaurora.org>,
	Shawn Guo <shawnguo@kernel.org>,
	Archit Taneja <archit.taneja@gmail.com>
Subject: Re: [PATCH] drm/panel: Add JDI LT070ME05000 WUXGA DSI Panel
Date: Thu, 14 Apr 2016 20:10:48 +0530	[thread overview]
Message-ID: <570FABF0.2090405@codeaurora.org> (raw)
In-Reply-To: <1460528887-22915-1-git-send-email-simhavcs@gmail.com>

On 4/13/2016 11:58 AM, Vinay Simha BN wrote:
> Add support for the JDI lt070me05000 WUXGA DSI panel used in
> Nexus 7 2013 devices.
>
> Programming sequence for the panel is was originally found in the
> android-msm-flo-3.4-lollipop-release branch from:
>      https://android.googlesource.com/kernel/msm.git
>
> And video mode setting is from dsi-panel-jdi-dualmipi1-video.dtsi
> file in:
>      git://codeaurora.org/kernel/msm-3.10.git  LNX.LA.3.6_rb1.27
>
> Other fixes folded in were provided
> by Archit Taneja <archit.taneja@gmail.com>
>
> Signed-off-by: Vinay Simha BN <simhavcs@gmail.com>
> [sumit.semwal: Ported to the drm/panel framework]
> Signed-off-by: Sumit Semwal <sumit.semwal@linaro.org>
> [jstultz: Cherry-picked to mainline, folded down other fixes
>   from Vinay and Archit]
> Signed-off-by: John Stultz <john.stultz@linaro.org>
> ---
>   .../bindings/display/panel/jdi,lt070me05000.txt    |  27 +
>   .../devicetree/bindings/vendor-prefixes.txt        |   1 +
>   drivers/gpu/drm/panel/Kconfig                      |  11 +
>   drivers/gpu/drm/panel/Makefile                     |   1 +
>   drivers/gpu/drm/panel/panel-jdi-lt070me05000.c     | 685 +++++++++++++++++++++
>   5 files changed, 725 insertions(+)
>   create mode 100644 Documentation/devicetree/bindings/display/panel/jdi,lt070me05000.txt
>   create mode 100644 drivers/gpu/drm/panel/panel-jdi-lt070me05000.c
>
> diff --git a/Documentation/devicetree/bindings/display/panel/jdi,lt070me05000.txt b/Documentation/devicetree/bindings/display/panel/jdi,lt070me05000.txt
> new file mode 100644
> index 0000000..35c5ac7
> --- /dev/null
> +++ b/Documentation/devicetree/bindings/display/panel/jdi,lt070me05000.txt
> @@ -0,0 +1,27 @@
> +JDI model LT070ME05000 1920x1200 7" DSI Panel
> +
> +Basic data sheet is at:
> +	http://panelone.net/en/7-0-inch/JDI_LT070ME05000_7.0_inch-datasheet
> +
> +This panel has video mode implemented currently in the driver.
> +
> +Required properties:
> +- compatible: should be "jdi,lt070me05000"
> +
> +Optional properties:
> +- power-supply: phandle of the regulator that provides the supply voltage
> +- reset-gpio: phandle of gpio for reset line
> +- backlight: phandle of the backlight device attached to the panel
> +
> +Example:
> +
> +	dsi@54300000 {
> +		panel: panel@0 {
> +			compatible = "jdi,lt070me05000";
> +			reg = <0>;
> +
> +			power-supply = <...>;
> +			reset-gpio = <...>;
> +			backlight = <...>;
> +		};
> +	};
> diff --git a/Documentation/devicetree/bindings/vendor-prefixes.txt b/Documentation/devicetree/bindings/vendor-prefixes.txt
> index a580f3e..ec42bb4 100644
> --- a/Documentation/devicetree/bindings/vendor-prefixes.txt
> +++ b/Documentation/devicetree/bindings/vendor-prefixes.txt
> @@ -130,6 +130,7 @@ invensense	InvenSense Inc.
>   isee	ISEE 2007 S.L.
>   isil	Intersil
>   issi	Integrated Silicon Solutions Inc.
> +jdi	Japan Display Inc.
>   jedec	JEDEC Solid State Technology Association
>   karo	Ka-Ro electronics GmbH
>   keymile	Keymile GmbH
> diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
> index 1500ab9..f41690e 100644
> --- a/drivers/gpu/drm/panel/Kconfig
> +++ b/drivers/gpu/drm/panel/Kconfig
> @@ -61,6 +61,17 @@ config DRM_PANEL_SHARP_LQ101R1SX01
>   	  To compile this driver as a module, choose M here: the module
>   	  will be called panel-sharp-lq101r1sx01.
>
> +config DRM_PANEL_JDI_LT070ME05000
> +	tristate "JDI LT070ME05000 WUXGA 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 JDI WUXGA DSI video/
> +	  command mode panel as found in Google Nexus 7 (2013) devices.
> +	  The panel has a 1200(RGB)×1920 (WUXGA) resolution and uses
> +	  24 bit RGB per pixel.
> +
>   config DRM_PANEL_SHARP_LS043T1LE01
>   	tristate "Sharp LS043T1LE01 qHD video mode panel"
>   	depends on OF
> diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
> index f277eed..e6c6fc8 100644
> --- a/drivers/gpu/drm/panel/Makefile
> +++ b/drivers/gpu/drm/panel/Makefile
> @@ -5,3 +5,4 @@ obj-$(CONFIG_DRM_PANEL_SAMSUNG_LD9040) += panel-samsung-ld9040.o
>   obj-$(CONFIG_DRM_PANEL_SAMSUNG_S6E8AA0) += panel-samsung-s6e8aa0.o
>   obj-$(CONFIG_DRM_PANEL_SHARP_LQ101R1SX01) += panel-sharp-lq101r1sx01.o
>   obj-$(CONFIG_DRM_PANEL_SHARP_LS043T1LE01) += panel-sharp-ls043t1le01.o
> +obj-$(CONFIG_DRM_PANEL_JDI_LT070ME05000) += panel-jdi-lt070me05000.o
> diff --git a/drivers/gpu/drm/panel/panel-jdi-lt070me05000.c b/drivers/gpu/drm/panel/panel-jdi-lt070me05000.c
> new file mode 100644
> index 0000000..051aa1b
> --- /dev/null
> +++ b/drivers/gpu/drm/panel/panel-jdi-lt070me05000.c
> @@ -0,0 +1,685 @@
> +/*
> + * Copyright (C) 2015 InforceComputing
> + * Author: Vinay Simha BN <simhavcs@gmail.com>
> + *
> + * Copyright (C) 2015 Linaro Ltd
> + * Author: Sumit Semwal <sumit.semwal@linaro.org>
> + *
> + * This program is free software; you can redistribute it and/or modify it
> + * under the terms of the GNU General Public License version 2 as published by
> + * the Free Software Foundation.
> + *
> + * This program is distributed in the hope that it will be useful, but WITHOUT
> + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> + * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
> + * more details.
> + *
> + * You should have received a copy of the GNU General Public License along with
> + * this program.  If not, see <http://www.gnu.org/licenses/>.
> + */
> +
> +#include <linux/backlight.h>
> +#include <linux/gpio/consumer.h>
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/regulator/consumer.h>
> +
> +#include <drm/drmP.h>
> +#include <drm/drm_crtc.h>
> +#include <drm/drm_mipi_dsi.h>
> +#include <drm/drm_panel.h>
> +
> +#include <video/mipi_display.h>
> +
> +/*
> + * From internet archives, the panel for Nexus 7 2nd Gen, 2013 model is a
> + * JDI model LT070ME05000, and its data sheet is at:
> + *  http://panelone.net/en/7-0-inch/JDI_LT070ME05000_7.0_inch-datasheet
> + */
> +struct jdi_panel {
> +	struct drm_panel base;
> +	struct mipi_dsi_device *dsi;
> +
> +	/* TODO: Add backilght support */
> +	struct backlight_device *backlight;
> +	struct regulator *supply;
> +	struct gpio_desc *reset_gpio;
> +	struct gpio_desc *enable_gpio;
> +	struct gpio_desc *vcc_gpio;
> +
> +	struct regulator *backlit;
> +	struct regulator *lvs7;
> +	struct regulator *avdd;
> +	struct regulator *iovdd;
> +	struct gpio_desc *pwm_gpio;
> +
> +	bool prepared;
> +	bool enabled;
> +
> +	const struct drm_display_mode *mode;
> +};
> +
> +static inline struct jdi_panel *to_jdi_panel(struct drm_panel *panel)
> +{
> +	return container_of(panel, struct jdi_panel, base);
> +}
> +
> +static char MCAP[2] = {0xB0, 0x00};
> +static char interface_setting_cmd[6] = {0xB3, 0x04, 0x08, 0x00, 0x22, 0x00};
> +static char interface_setting[6] = {0xB3, 0x26, 0x08, 0x00, 0x20, 0x00};
> +
> +static char interface_ID_setting[2] = {0xB4, 0x0C};
> +static char DSI_control[3] = {0xB6, 0x3A, 0xD3};
> +
> +static char tear_scan_line[3] = {0x44, 0x03, 0x00};
> +
> +/* for fps control, set fps to 60.32Hz */
> +static char LTPS_timing_setting[2] = {0xC6, 0x78};
> +static char sequencer_timing_control[2] = {0xD6, 0x01};
> +
> +/* set brightness */
> +static char write_display_brightness[] = {0x51, 0xFF};
> +/* enable LEDPWM pin output, turn on LEDPWM output, turn off pwm dimming */
> +static char write_control_display[] = {0x53, 0x24};
> +/*
> + * choose cabc mode, 0x00(-0%), 0x01(-15%), 0x02(-40%), 0x03(-54%),
> + * disable SRE(sunlight readability enhancement)
> + */
> +static char write_cabc[] = {0x55, 0x00};
> +/* for cabc mode 0x1(-15%) */
> +static char backlight_control1[] = {0xB8, 0x07, 0x87, 0x26, 0x18, 0x00, 0x32};
> +/* for cabc mode 0x2(-40%) */
> +static char backlight_control2[] = {0xB9, 0x07, 0x75, 0x61, 0x20, 0x16, 0x87};
> +/* for cabc mode 0x3(-54%) */
> +static char backlight_control3[] = {0xBA, 0x07, 0x70, 0x81, 0x20, 0x45, 0xB4};
> +/* for pwm frequency and dimming control */
> +static char backlight_control4[] = {0xCE, 0x7D, 0x40, 0x48, 0x56, 0x67, 0x78,
> +		0x88, 0x98, 0xA7, 0xB5, 0xC3, 0xD1, 0xDE, 0xE9, 0xF2, 0xFA,
> +		0xFF, 0x37, 0xF5, 0x0F, 0x0F, 0x42, 0x00};

Apart from the u8 conversion as mentioned by Thierry, you should
convert these to const too.

> +
> +static int jdi_panel_init(struct jdi_panel *jdi)
> +{
> +	struct mipi_dsi_device *dsi = jdi->dsi;
> +	int ret;
> +
> +	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
> +
> +	if (dsi->mode_flags & MIPI_DSI_MODE_VIDEO) {
> +		ret = mipi_dsi_dcs_soft_reset(dsi);
> +		if (ret < 0)
> +			return ret;
> +
> +		mdelay(10);
> +
> +		ret = mipi_dsi_dcs_set_pixel_format(dsi, 0x70);
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_dcs_set_column_address(dsi, 0x0000, 0x04AF);
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_dcs_set_page_address(dsi, 0x0000, 0x077F);
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_dcs_set_tear_on(dsi,
> +					       MIPI_DSI_DCS_TEAR_MODE_VBLANK);
> +		if (ret < 0)
> +			return ret;
> +		mdelay(5);
> +
> +		ret = mipi_dsi_generic_write(dsi, tear_scan_line,
> +					     sizeof(tear_scan_line));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_dcs_write_buffer(dsi, write_display_brightness,
> +						sizeof(write_display_brightness)
> +						);
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_dcs_write_buffer(dsi, write_control_display,
> +						sizeof(write_control_display));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_dcs_write_buffer(dsi, write_cabc,
> +						sizeof(write_cabc));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
> +		if (ret < 0)
> +			return ret;
> +		mdelay(120);
> +
> +		ret = mipi_dsi_generic_write(dsi, MCAP, sizeof(MCAP));
> +		if (ret < 0)
> +			return ret;
> +		mdelay(10);
> +
> +		ret = mipi_dsi_generic_write(dsi, interface_setting,
> +					     sizeof(interface_setting));
> +		if (ret < 0)
> +			return ret;
> +		mdelay(20);
> +
> +		backlight_control4[18] = 0x04;
> +		backlight_control4[19] = 0x00;

Any reason why these are overwritten? It would be better to have these
values in the array itself.

> +
> +		ret = mipi_dsi_generic_write(dsi, backlight_control4,
> +					     sizeof(backlight_control4));
> +		if (ret < 0)
> +			return ret;
> +		mdelay(20);
> +
> +		MCAP[1] = 0x03;
> +		ret = mipi_dsi_generic_write(dsi, MCAP, sizeof(MCAP));
> +		if (ret < 0)
> +			return ret;
> +	} else {
> +		/*
> +		 * TODO : need to verify panel settings when
> +		 * dsi cmd mode supported for apq8064 - simhavcs
> +		 */
> +		ret = mipi_dsi_dcs_soft_reset(dsi);
> +		if (ret < 0)
> +			return ret;
> +
> +		mdelay(5);
> +
> +		ret = mipi_dsi_generic_write(dsi, MCAP, sizeof(MCAP));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_generic_write(dsi, interface_setting_cmd,
> +					     sizeof(interface_setting_cmd));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_generic_write(dsi, interface_ID_setting,
> +					     sizeof(interface_ID_setting));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_generic_write(dsi, DSI_control,
> +					     sizeof(DSI_control));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_generic_write(dsi, LTPS_timing_setting,
> +					     sizeof(LTPS_timing_setting));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_generic_write(dsi, sequencer_timing_control,
> +					     sizeof(sequencer_timing_control));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_dcs_write_buffer(dsi, write_display_brightness,
> +						sizeof(write_display_brightness)
> +						);
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_dcs_write_buffer(dsi, write_control_display,
> +						sizeof(write_control_display));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_dcs_write_buffer(dsi, write_cabc,
> +						sizeof(write_cabc));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_generic_write(dsi, backlight_control1,
> +					     sizeof(backlight_control1));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_generic_write(dsi, backlight_control2,
> +					     sizeof(backlight_control2));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_generic_write(dsi, backlight_control3,
> +					     sizeof(backlight_control3));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_generic_write(dsi, backlight_control4,
> +					     sizeof(backlight_control4));
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_dcs_set_pixel_format(dsi, 0x77);
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_dcs_set_column_address(dsi, 0x0000, 0x04AF);
> +		if (ret < 0)
> +			return ret;
> +
> +		ret = mipi_dsi_dcs_set_page_address(dsi, 0x0000, 0x077F);
> +		if (ret < 0)
> +			return ret;
> +		mdelay(120);
> +
> +		ret = mipi_dsi_dcs_exit_sleep_mode(dsi);
> +		if (ret < 0)
> +			return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +static int jdi_panel_on(struct jdi_panel *jdi)
> +{
> +	struct mipi_dsi_device *dsi = jdi->dsi;
> +	int ret;
> +
> +	dsi->mode_flags |= MIPI_DSI_MODE_LPM;
> +
> +	ret = mipi_dsi_dcs_set_display_on(dsi);
> +	if (ret < 0)
> +		return ret;
> +
> +	return 0;
> +}
> +
> +static int jdi_panel_off(struct jdi_panel *jdi)
> +{
> +	struct mipi_dsi_device *dsi = jdi->dsi;
> +	int ret;
> +
> +	dsi->mode_flags &= ~MIPI_DSI_MODE_LPM;
> +
> +	ret = mipi_dsi_dcs_set_display_off(dsi);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = mipi_dsi_dcs_enter_sleep_mode(dsi);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = mipi_dsi_dcs_set_tear_off(dsi);
> +	if (ret < 0)
> +		return ret;
> +
> +	msleep(100);
> +
> +	return 0;
> +}
> +
> +static int jdi_panel_disable(struct drm_panel *panel)
> +{
> +	struct jdi_panel *jdi = to_jdi_panel(panel);
> +
> +	if (!jdi->enabled)
> +		return 0;
> +
> +	DRM_DEBUG("disable\n");
> +
> +	if (jdi->backlight) {
> +		jdi->backlight->props.power = FB_BLANK_POWERDOWN;
> +		backlight_update_status(jdi->backlight);
> +	}
> +
> +	jdi->enabled = false;
> +
> +	return 0;
> +}
> +
> +static int jdi_panel_unprepare(struct drm_panel *panel)
> +{
> +	struct jdi_panel *jdi = to_jdi_panel(panel);
> +	int ret;
> +
> +	if (!jdi->prepared)
> +		return 0;
> +
> +	DRM_DEBUG("unprepare\n");
> +
> +	ret = jdi_panel_off(jdi);
> +	if (ret) {
> +		dev_err(panel->dev, "failed to set panel off: %d\n", ret);
> +		return ret;
> +	}
> +
> +	regulator_disable(jdi->supply);
> +
> +	if (jdi->vcc_gpio)
> +		gpiod_set_value(jdi->vcc_gpio, 0);
> +
> +	if (jdi->reset_gpio)
> +		gpiod_set_value(jdi->reset_gpio, 0);
> +
> +	if (jdi->enable_gpio)
> +		gpiod_set_value(jdi->enable_gpio, 0);
> +
> +	jdi->prepared = false;
> +
> +	return 0;
> +}
> +
> +static int jdi_panel_prepare(struct drm_panel *panel)
> +{
> +	struct jdi_panel *jdi = to_jdi_panel(panel);
> +	int ret;
> +
> +	if (jdi->prepared)
> +		return 0;
> +
> +	DRM_DEBUG("prepare\n");
> +
> +	ret = regulator_enable(jdi->iovdd);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = regulator_enable(jdi->avdd);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = regulator_enable(jdi->backlit);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = regulator_enable(jdi->lvs7);
> +	if (ret < 0)
> +		return ret;
> +
> +	ret = regulator_enable(jdi->supply);
> +	if (ret < 0)
> +		return ret;
> +
> +	msleep(20);
> +
> +	if (jdi->vcc_gpio) {
> +		gpiod_set_value(jdi->vcc_gpio, 1);
> +		usleep_range(10, 20);
> +	}
> +
> +	if (jdi->reset_gpio) {
> +		gpiod_set_value(jdi->reset_gpio, 1);
> +		usleep_range(10, 20);
> +	}
> +
> +	if (jdi->pwm_gpio) {
> +		gpiod_set_value(jdi->pwm_gpio, 1);
> +		usleep_range(10, 20);
> +	}
> +
> +	if (jdi->enable_gpio) {
> +		gpiod_set_value(jdi->enable_gpio, 1);
> +		usleep_range(10, 20);
> +	}
> +
> +	ret = jdi_panel_init(jdi);
> +	if (ret) {
> +		dev_err(panel->dev, "failed to init panel: %d\n", ret);
> +		goto poweroff;
> +	}
> +
> +	ret = jdi_panel_on(jdi);
> +	if (ret) {
> +		dev_err(panel->dev, "failed to set panel on: %d\n", ret);
> +		goto poweroff;
> +	}
> +
> +	jdi->prepared = true;
> +
> +	return 0;
> +
> +poweroff:
> +	regulator_disable(jdi->supply);
> +	if (jdi->reset_gpio)
> +		gpiod_set_value(jdi->reset_gpio, 0);
> +	if (jdi->enable_gpio)
> +		gpiod_set_value(jdi->enable_gpio, 0);
> +	if (jdi->vcc_gpio)
> +		gpiod_set_value(jdi->vcc_gpio, 0);
> +
> +	return ret;
> +}
> +
> +static int jdi_panel_enable(struct drm_panel *panel)
> +{
> +	struct jdi_panel *jdi = to_jdi_panel(panel);
> +
> +	if (jdi->enabled)
> +		return 0;
> +
> +	DRM_DEBUG("enable\n");
> +
> +	if (jdi->backlight) {
> +		jdi->backlight->props.power = FB_BLANK_UNBLANK;
> +		backlight_update_status(jdi->backlight);
> +	}
> +
> +	jdi->enabled = true;
> +
> +	return 0;
> +}

The prepare/enable split seems a bit strange. Don't we want to put
mipi_dsi_dcs_set_display_on in the enable() op too?

> +
> +static const struct drm_display_mode default_mode = {
> +		.clock = 155000,

htotal * vtotal * vrefresh (1934 * 1340 * 60.32(as in comment)) comes
at around 156.3 Mhz. Could you plug in the correct frequency?

> +		.hdisplay = 1200,
> +		.hsync_start = 1200 + 48,
> +		.hsync_end = 1200 + 48 + 32,
> +		.htotal = 1200 + 48 + 32 + 60,
> +		.vdisplay = 1920,
> +		.vsync_start = 1920 + 3,
> +		.vsync_end = 1920 + 3 + 5,
> +		.vtotal = 1920 + 3 + 5 + 6,
> +		.vrefresh = 60,
> +		.flags = 0,
> +};
> +
> +static int jdi_panel_get_modes(struct drm_panel *panel)
> +{
> +	struct drm_display_mode *mode;
> +
> +	mode = drm_mode_duplicate(panel->drm, &default_mode);
> +	if (!mode) {
> +		dev_err(panel->drm->dev, "failed to add mode %ux%ux@%u\n",
> +			default_mode.hdisplay, default_mode.vdisplay,
> +			default_mode.vrefresh);

We should use the dsi->dev device pointer here like used elsewhere, not
the drm device pointer.

> +		return -ENOMEM;
> +	}
> +
> +	drm_mode_set_name(mode);
> +
> +	drm_mode_probed_add(panel->connector, mode);
> +
> +	return 1;
> +}
> +
> +static const struct drm_panel_funcs jdi_panel_funcs = {
> +		.disable = jdi_panel_disable,
> +		.unprepare = jdi_panel_unprepare,
> +		.prepare = jdi_panel_prepare,
> +		.enable = jdi_panel_enable,
> +		.get_modes = jdi_panel_get_modes,
> +};
> +
> +static const struct of_device_id jdi_of_match[] = {
> +		{ .compatible = "jdi,lt070me05000", },
> +		{ }
> +};
> +MODULE_DEVICE_TABLE(of, jdi_of_match);
> +
> +static int jdi_panel_add(struct jdi_panel *jdi)
> +{
> +	struct device *dev = &jdi->dsi->dev;
> +	int ret;
> +
> +	jdi->mode = &default_mode;
> +
> +	/* lvs5 */
> +	jdi->supply = devm_regulator_get(dev, "power");
> +	if (IS_ERR(jdi->supply))
> +		return PTR_ERR(jdi->supply);

You could consider using regulator_get_bulk() api here, it would clean
up the code a bit.

> +
> +	/* l17 */
> +	jdi->backlit = devm_regulator_get(dev, "backlit");
> +	if (IS_ERR(jdi->supply))
> +		return PTR_ERR(jdi->supply);
> +
> +	jdi->lvs7 = devm_regulator_get(dev, "lvs7");
> +	if (IS_ERR(jdi->lvs7))
> +		return PTR_ERR(jdi->lvs7);
> +
> +	jdi->avdd = devm_regulator_get(dev, "avdd");
> +	if (IS_ERR(jdi->avdd))
> +		return PTR_ERR(jdi->avdd);
> +
> +	jdi->iovdd = devm_regulator_get(dev, "iovdd");
> +	if (IS_ERR(jdi->iovdd))
> +		return PTR_ERR(jdi->iovdd);
> +
> +	jdi->vcc_gpio = devm_gpiod_get(dev, "vcc", GPIOD_OUT_LOW);
> +	if (IS_ERR(jdi->vcc_gpio)) {
> +		dev_err(dev, "cannot get vcc-gpio %ld\n",
> +			PTR_ERR(jdi->vcc_gpio));
> +		jdi->vcc_gpio = NULL;
> +	} else {
> +		gpiod_direction_output(jdi->vcc_gpio, 0);
> +	}
> +
> +	jdi->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW);
> +	if (IS_ERR(jdi->reset_gpio)) {
> +		dev_err(dev, "cannot get reset-gpios %ld\n",
> +			PTR_ERR(jdi->reset_gpio));
> +		jdi->reset_gpio = NULL;
> +	} else {
> +		gpiod_direction_output(jdi->reset_gpio, 0);
> +	}
> +
> +	jdi->enable_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW);
> +	if (IS_ERR(jdi->enable_gpio)) {
> +		dev_err(dev, "cannot get enable-gpio %ld\n",
> +			PTR_ERR(jdi->enable_gpio));
> +		jdi->enable_gpio = NULL;
> +	} else {
> +		gpiod_direction_output(jdi->enable_gpio, 0);
> +	}
> +
> +	jdi->pwm_gpio = devm_gpiod_get(dev, "pwm", GPIOD_OUT_LOW);
> +	if (IS_ERR(jdi->pwm_gpio)) {
> +		dev_err(dev, "cannot get pwm-gpio %ld\n",
> +			PTR_ERR(jdi->pwm_gpio));
> +		jdi->pwm_gpio = NULL;
> +	} else {
> +		gpiod_direction_output(jdi->pwm_gpio, 0);
> +	}
> +
> +	/* we don't have backlight right now, proceed further */
> +#ifdef BACKLIGHT
> +	np = of_parse_phandle(dev->of_node, "backlight", 0);
> +	if (np) {
> +		jdi->backlight = of_find_backlight_by_node(np);
> +		of_node_put(np);
> +
> +		if (!jdi->backlight)
> +			return -EPROBE_DEFER;
> +	}
> +#endif
> +
> +	drm_panel_init(&jdi->base);
> +	jdi->base.funcs = &jdi_panel_funcs;
> +	jdi->base.dev = &jdi->dsi->dev;
> +
> +	ret = drm_panel_add(&jdi->base);
> +	if (ret < 0)
> +		goto put_backlight;
> +
> +	return 0;
> +
> +put_backlight:
> +	if (jdi->backlight)
> +		put_device(&jdi->backlight->dev);
> +
> +	return ret;
> +}
> +
> +static void jdi_panel_del(struct jdi_panel *jdi)
> +{
> +	if (jdi->base.dev)
> +		drm_panel_remove(&jdi->base);
> +
> +	if (jdi->backlight)
> +		put_device(&jdi->backlight->dev);
> +}
> +
> +static int jdi_panel_probe(struct mipi_dsi_device *dsi)
> +{
> +	struct jdi_panel *jdi;
> +	int ret;
> +
> +	dsi->lanes = 4;
> +	dsi->format = MIPI_DSI_FMT_RGB888;
> +	dsi->mode_flags =  MIPI_DSI_MODE_VIDEO_HSE | MIPI_DSI_MODE_VIDEO |
> +			MIPI_DSI_MODE_VIDEO_HFP | MIPI_DSI_MODE_VIDEO_HBP |
> +			MIPI_DSI_MODE_VIDEO_HSA |
> +			MIPI_DSI_CLOCK_NON_CONTINUOUS;
> +
> +	jdi = devm_kzalloc(&dsi->dev, sizeof(*jdi), GFP_KERNEL);
> +	if (!jdi)
> +		return -ENOMEM;
> +
> +	mipi_dsi_set_drvdata(dsi, jdi);
> +
> +	jdi->dsi = dsi;
> +
> +	ret = jdi_panel_add(jdi);
> +	if (ret < 0)
> +		return ret;
> +
> +	return mipi_dsi_attach(dsi);
> +}
> +
> +static int jdi_panel_remove(struct mipi_dsi_device *dsi)
> +{
> +	struct jdi_panel *jdi = mipi_dsi_get_drvdata(dsi);
> +	int ret;
> +
> +	ret = jdi_panel_disable(&jdi->base);
> +	if (ret < 0)
> +		dev_err(&dsi->dev, "failed to disable panel: %d\n", ret);

Ideally, the driver's remove op shouldn't try to disable the panel. It
should be done by the dsi host's connector itself. We can drop this
unless there is a specfic reason to do so.

Thanks for working on this.

Archit

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