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In-Reply-To: <570FABF0.2090405@codeaurora.org>
References: <1460528887-22915-1-git-send-email-simhavcs@gmail.com>
	<570FABF0.2090405@codeaurora.org>
Date: Wed, 20 Apr 2016 15:16:34 +0530
Message-ID: <CAGWqDJ6mgXLL-HghAFnNiBpzKicNnY5zP2eqLmLjcyUdLWJd2Q@mail.gmail.com>
Subject: Re: [PATCH] drm/panel: Add JDI LT070ME05000 WUXGA DSI Panel
From: Vinay Simha <simhavcs@gmail.com>
To: Archit Taneja <architt@codeaurora.org>
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>
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On Thu, Apr 14, 2016 at 8:10 PM, Archit Taneja <architt@codeaurora.org> wrote:
>
>
> 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?
enable will be called after the prepare().
enable() - usually the backlight update status BLANK/UNBLANK is done
>
>> +
>> +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.
>
panel_disable() - sets the backlight brightness off
fyi,
include/drm/drm_panel.h
Before stopping video transmission from the display controller it can be
necessary to turn off the panel to avoid visual glitches. This is done in
the .disable() function.
> Thanks for working on this.
>
> Archit
>
> --
> Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum,
> a Linux Foundation Collaborative Project


-- 
Regards,

Vinay Simha.B.N.