Re: [PATCH v5 2/2] drm: panel: Add novatek nt36672a panel driver

Hi Sam,

On Sun, 30 Aug 2020 at 03:01, Sam Ravnborg sam@ravnborg.org wrote:

Hi Sumit.

On Wed, Aug 26, 2020 at 09:33:08PM +0530, Sumit Semwal wrote:

...

Novatek NT36672a is a generic DSI IC that drives command and video mode panels. Add the driver for it.

Right now adding support for some Poco F1 phones that have an LCD panel from Tianma connected with this IC, with a resolution of 1080x2246 that operates in DSI video mode.

During testing, Benni Steini bennisteinir@gmail.com helped us fix the reset sequence timing (from 10ms to 20ms), to get the bootanimation to work on Android.

With current AOSP, we need to increase it to 200ms - this seems to be a safe high value to avoid a white screen occasionally.

Signed-off-by: Sumit Semwal sumit.semwal@linaro.org Cc: Benni Steini bennisteinir@gmail.com

---

v2: increase reset sequence timing to a safe 200ms v4: Since "0425662fdf05: drm: Nuke mode->vrefresh", we have to calculate vrefresh on demand. Update for it. v5: Fixed review comments from Sam: - rebased on top of drm-misc-next remove return of drm_panel_add() remove drm_panel_detach() - renamed the panel driver file to reflect that this is a novatek nt36672a display driver and not only for tianma panels. Adjusted some internal names also to reflect the same. - corrected changelog to add info about the generic Novatek DSI IC - corrected compatible string accordingly - removed pinctrl - used drm_panel* API for prepare/unprepare/disable/remove

Thanks for the detailed follow-up - very nice.

A few things slipped thought last review and we have gained support for dv_err_probe() now. Also dev_err() and friends are now the right choice for panel drivers.

Thanks very much for your detailed review :) - I have incorporated the review comments, and will send v6 (hopefully last :) ) in a short while.

    Sam

...

---

MAINTAINERS | 7 + drivers/gpu/drm/panel/Kconfig | 10 + drivers/gpu/drm/panel/Makefile | 1 + .../gpu/drm/panel/panel-novatek-nt36672a.c | 767 ++++++++++++++++++ 4 files changed, 785 insertions(+) create mode 100644 drivers/gpu/drm/panel/panel-novatek-nt36672a.c

diff --git a/MAINTAINERS b/MAINTAINERS index 01fb9ee6b951..aeecade2d65f 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -5619,6 +5619,13 @@ T: git git://anongit.freedesktop.org/drm/drm-misc F: Documentation/devicetree/bindings/display/ste,mcde.txt F: drivers/gpu/drm/mcde/

+DRM DRIVER FOR TIANMA NT36672A PANELS +M: Sumit Semwal sumit.semwal@linaro.org +S: Maintained +T: git git://anongit.freedesktop.org/drm/drm-misc +F: Documentation/devicetree/bindings/display/panel/tianma,nt36672a-panel.yaml +F: drivers/gpu/drm/panel/panel-tianma-nt36672a.c

DRM DRIVER FOR TDFX VIDEO CARDS S: Orphan / Obsolete F: drivers/gpu/drm/tdfx/ diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig index 8d97d07c5871..02600f12a063 100644 --- a/drivers/gpu/drm/panel/Kconfig +++ b/drivers/gpu/drm/panel/Kconfig @@ -208,6 +208,16 @@ config DRM_PANEL_NOVATEK_NT35510 around the Novatek NT35510 display controller, such as some Hydis panels.

+config DRM_PANEL_NOVATEK_NT36672A

• tristate "Novatek NT36672A 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 panels built
  

•   around the Novatek NT36672A display controller, such as some
  

•   Tianma panels used in a few Xiaomi Poco F1 mobile phone.
  

config DRM_PANEL_NOVATEK_NT39016 tristate "Novatek NT39016 RGB/SPI panel" depends on OF && SPI diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile index 15a4e7752951..4a36eb45f670 100644 --- a/drivers/gpu/drm/panel/Makefile +++ b/drivers/gpu/drm/panel/Makefile @@ -19,6 +19,7 @@ obj-$(CONFIG_DRM_PANEL_LG_LB035Q02) += panel-lg-lb035q02.o obj-$(CONFIG_DRM_PANEL_LG_LG4573) += panel-lg-lg4573.o obj-$(CONFIG_DRM_PANEL_NEC_NL8048HL11) += panel-nec-nl8048hl11.o obj-$(CONFIG_DRM_PANEL_NOVATEK_NT35510) += panel-novatek-nt35510.o +obj-$(CONFIG_DRM_PANEL_NOVATEK_NT36672A) += panel-novatek-nt36672a.o obj-$(CONFIG_DRM_PANEL_NOVATEK_NT39016) += panel-novatek-nt39016.o obj-$(CONFIG_DRM_PANEL_MANTIX_MLAF057WE51) += panel-mantix-mlaf057we51.o obj-$(CONFIG_DRM_PANEL_OLIMEX_LCD_OLINUXINO) += panel-olimex-lcd-olinuxino.o diff --git a/drivers/gpu/drm/panel/panel-novatek-nt36672a.c b/drivers/gpu/drm/panel/panel-novatek-nt36672a.c new file mode 100644 index 000000000000..3f0c18e46818 --- /dev/null +++ b/drivers/gpu/drm/panel/panel-novatek-nt36672a.c @@ -0,0 +1,767 @@ +// SPDX-License-Identifier: GPL-2.0+ +/*

• • Copyright (C) 2020 Linaro Ltd
• • Author: Sumit Semwal sumit.semwal@linaro.org
• • This driver is for the DSI interface to panels using the NT36672A display driver IC
• • from Novatek.
• • Currently supported are the Tianma FHD+ panels found in some Xiaomi phones, including
• • some variants of the Poco F1 phone.
• • Panels using the Novatek NT37762A IC should add appropriate configuration per-panel and
• • use this driver.
• */

+#include <linux/delay.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/of.h> +#include <linux/of_device.h>

+#include <linux/gpio/consumer.h> +#include <linux/pinctrl/consumer.h> +#include <linux/regulator/consumer.h>

+#include <drm/drm_device.h> +#include <drm/drm_mipi_dsi.h> +#include <drm/drm_modes.h> +#include <drm/drm_panel.h> +#include <drm/drm_print.h>

panels no longer use DRM_* for error print - use dev_err() and friends. And then this include can go as well.

...

+#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[] = {

• "vddio",
  

• "vddpos",
  

• "vddneg",
  

+};

+static unsigned long const regulator_enable_loads[] = {

• 62000,
  

• 100000,
  

• 100000
  

+};

+static unsigned long const regulator_disable_loads[] = {

• 80,
  

• 100,
  

• 100
  

+};

+struct panel_desc {

• const struct drm_display_mode *display_mode;
  

• const char *panel_name;
  

• unsigned int width_mm;
  

• unsigned int height_mm;
  

• unsigned long mode_flags;
  

• enum mipi_dsi_pixel_format format;
  

• unsigned int lanes;
  

• const struct panel_cmd *on_cmds_1;
  

• const struct panel_cmd *on_cmds_2;
  

• const struct panel_cmd *off_cmds;
  

+};

+struct panel_info {

• struct drm_panel base;
  

• struct mipi_dsi_device *link;
  

• const struct panel_desc *desc;
  

• struct regulator_bulk_data supplies[ARRAY_SIZE(regulator_names)];
  

• struct gpio_desc *reset_gpio;
  

• bool prepared;
  

• bool enabled;
  

There is no need for the enabled flag.

...

+};

+static inline struct panel_info *to_panel_info(struct drm_panel *panel) +{

• return container_of(panel, struct panel_info, base);
  

+}

+static int send_mipi_cmds(struct drm_panel *panel, const struct panel_cmd *cmds) +{

• struct panel_info *pinfo = to_panel_info(panel);
  

• unsigned int i = 0;
  

• int err;
  

• if (!cmds)
  

•         return -EFAULT;
  

• for (i = 0; cmds[i].len != 0; i++) {
  

•         const struct panel_cmd *cmd = &cmds[i];
  

•         if (cmd->len == 2)
  

•                 err = mipi_dsi_dcs_write(pinfo->link,
  

•                                          cmd->data[1], NULL, 0);
  

•         else
  

•                 err = mipi_dsi_dcs_write(pinfo->link,
  

•                                          cmd->data[1], cmd->data + 2,
  

•                                          cmd->len - 2);
  

•         if (err < 0)
  

•                 return err;
  

• }
  

• return 0;
  

+}

+static int nt36672a_panel_disable(struct drm_panel *panel) +{

• struct panel_info *pinfo = to_panel_info(panel);
  

• pinfo->enabled = false;
  

• return 0;
  

+}

The nt36672a_panel_disable() does not do anything - delete it.

...

+static int novatek_panel_power_off(struct drm_panel *panel) +{

• struct panel_info *pinfo = to_panel_info(panel);
  

• int i, ret = 0;
  

• gpiod_set_value(pinfo->reset_gpio, 0);
  

• for (i = 0; i < ARRAY_SIZE(pinfo->supplies); i++) {
  

•         ret = regulator_set_load(pinfo->supplies[i].consumer,
  

•                                  regulator_disable_loads[i]);
  

•         if (ret) {
  

•                 DRM_DEV_ERROR(panel->dev, "regulator_set_load failed %d\n", ret);
  

USe dev_err(...) here, likewise for other similar uses.

...

•                 return ret;
  

•         }
  

• }
  

• ret = regulator_bulk_disable(ARRAY_SIZE(pinfo->supplies), pinfo->supplies);
  

• if (ret)
  

•         DRM_DEV_ERROR(panel->dev, "regulator_bulk_disable failed %d\n", ret);
  

• return ret;
  

+}

+static int nt36672a_panel_unprepare(struct drm_panel *panel) +{

• struct panel_info *pinfo = to_panel_info(panel);
  

• int ret;
  

• if (!pinfo->prepared)
  

•         return 0;
  

• /* send off cmds */
  

• ret = send_mipi_cmds(panel, pinfo->desc->off_cmds);
  

• if (ret < 0)
  

•         DRM_DEV_ERROR(panel->dev, "failed to send DCS off cmds: %d\n", ret);
  

• ret = mipi_dsi_dcs_set_display_off(pinfo->link);
  

• if (ret < 0)
  

•         DRM_DEV_ERROR(panel->dev, "set_display_off cmd failed ret = %d\n", ret);
  

• /* 120ms delay required here as per DCS spec */
  

• msleep(120);
  

• ret = mipi_dsi_dcs_enter_sleep_mode(pinfo->link);
  

• if (ret < 0)
  

•         DRM_DEV_ERROR(panel->dev, "enter_sleep cmd failed ret = %d\n", ret);
  

• /* 0x3C = 60ms delay */
  

• msleep(60);
  

• ret = novatek_panel_power_off(panel);
  

• if (ret < 0)
  

•         DRM_DEV_ERROR(panel->dev, "power_off failed ret = %d\n", ret);
  

• pinfo->prepared = false;
  

• return ret;
  

+}

+static int novatek_panel_power_on(struct panel_info *pinfo) +{

• int ret, i;
  

• for (i = 0; i < ARRAY_SIZE(pinfo->supplies); i++) {
  

•         ret = regulator_set_load(pinfo->supplies[i].consumer,
  

•                                  regulator_enable_loads[i]);
  

•         if (ret)
  

•                 return ret;
  

• }
  

• ret = regulator_bulk_enable(ARRAY_SIZE(pinfo->supplies), pinfo->supplies);
  

• if (ret < 0)
  

•         return ret;
  

• /*
  

•  * As per downstream kernel, Reset sequence of Tianma FHD panel requires the panel to
  

•  * be out of reset for 10ms, followed by being held in reset for 10ms. But for Android
  

•  * AOSP, we needed to bump it upto 200ms otherwise we get white screen sometimes.
  

•  * FIXME: Try to reduce this 200ms to a lesser value.
  

•  */
  

• gpiod_set_value(pinfo->reset_gpio, 0);
  

• msleep(200);
  

• gpiod_set_value(pinfo->reset_gpio, 1);
  

• msleep(200);
  

• return 0;
  

+}

+static int nt36672a_panel_prepare(struct drm_panel *panel) +{

• struct panel_info *pinfo = to_panel_info(panel);
  

• int err;
  

• if (pinfo->prepared)
  

•         return 0;
  

• err = novatek_panel_power_on(pinfo);
  

• if (err < 0)
  

•         goto poweroff;
  

• /* send first part of init cmds */
  

• err = send_mipi_cmds(panel, pinfo->desc->on_cmds_1);
  

• if (err < 0) {
  

•         DRM_DEV_ERROR(panel->dev, "failed to send DCS Init 1st Code: %d\n", err);
  

•         goto poweroff;
  

• }
  

• err = mipi_dsi_dcs_exit_sleep_mode(pinfo->link);
  

• if (err < 0) {
  

•         DRM_DEV_ERROR(panel->dev, "failed to exit sleep mode: %d\n", err);
  

•         goto poweroff;
  

• }
  

• /* 0x46 = 70 ms delay */
  

• msleep(70);
  

• err = mipi_dsi_dcs_set_display_on(pinfo->link);
  

• if (err < 0) {
  

•         DRM_DEV_ERROR(panel->dev, "failed to Set Display ON: %d\n", err);
  

•         goto poweroff;
  

• }
  

• /* Send rest of the init cmds */
  

• err = send_mipi_cmds(panel, pinfo->desc->on_cmds_2);
  

• if (err < 0) {
  

•         DRM_DEV_ERROR(panel->dev, "failed to send DCS Init 2nd Code: %d\n", err);
  

•         goto poweroff;
  

• }
  

• msleep(120);
  

• pinfo->prepared = true;
  

• return 0;
  

+poweroff:

• gpiod_set_value(pinfo->reset_gpio, 1);
  

• return err;
  

+}

+static int nt36672a_panel_enable(struct drm_panel *panel) +{

• struct panel_info *pinfo = to_panel_info(panel);
  

• pinfo->enabled = true;
  

• return 0;
  

+}

This function do not do anything - drop it.

...

+static int nt36672a_panel_get_modes(struct drm_panel *panel,

•                             struct drm_connector *connector)
  

+{

• struct panel_info *pinfo = to_panel_info(panel);
  

• const struct drm_display_mode *m = pinfo->desc->display_mode;
  

• struct drm_display_mode *mode;
  

• mode = drm_mode_duplicate(connector->dev, m);
  

• if (!mode) {
  

•         DRM_DEV_ERROR(panel->dev, "failed to add mode %ux%u@%u\n",
  

•                       m->hdisplay, m->vdisplay, drm_mode_vrefresh(m));
  

•         return -ENOMEM;
  

• }
  

• connector->display_info.width_mm = pinfo->desc->width_mm;
  

• connector->display_info.height_mm = pinfo->desc->height_mm;
  

• drm_mode_set_name(mode);
  

• drm_mode_probed_add(connector, mode);
  

• return 1;
  

+}

+static const struct drm_panel_funcs panel_funcs = {

• .disable = nt36672a_panel_disable,
  

• .unprepare = nt36672a_panel_unprepare,
  

• .prepare = nt36672a_panel_prepare,
  

• .enable = nt36672a_panel_enable,
  

• .get_modes = nt36672a_panel_get_modes,
  

+};

+static const struct panel_cmd tianma_fhd_video_on_cmds_1[] = {

• /* skin enhancement mode */
  

• _INIT_CMD(0x00, 0xFF, 0x22),
  

• _INIT_CMD(0x00, 0x00, 0x40),
  

• _INIT_CMD(0x00, 0x01, 0xC0),
  

• _INIT_CMD(0x00, 0x02, 0x40),
  

• _INIT_CMD(0x00, 0x03, 0x40),
  

• _INIT_CMD(0x00, 0x04, 0x40),
  

• _INIT_CMD(0x00, 0x05, 0x40),
  

• _INIT_CMD(0x00, 0x06, 0x40),
  

• _INIT_CMD(0x00, 0x07, 0x40),
  

• _INIT_CMD(0x00, 0x08, 0x40),
  

• _INIT_CMD(0x00, 0x09, 0x40),
  

• _INIT_CMD(0x00, 0x0A, 0x40),
  

• _INIT_CMD(0x00, 0x0B, 0x40),
  

• _INIT_CMD(0x00, 0x0C, 0x40),
  

• _INIT_CMD(0x00, 0x0D, 0x40),
  

• _INIT_CMD(0x00, 0x0E, 0x40),
  

• _INIT_CMD(0x00, 0x0F, 0x40),
  

• _INIT_CMD(0x00, 0x10, 0x40),
  

• _INIT_CMD(0x00, 0x11, 0x50),
  

• _INIT_CMD(0x00, 0x12, 0x60),
  

• _INIT_CMD(0x00, 0x13, 0x70),
  

• _INIT_CMD(0x00, 0x14, 0x58),
  

• _INIT_CMD(0x00, 0x15, 0x68),
  

• _INIT_CMD(0x00, 0x16, 0x78),
  

• _INIT_CMD(0x00, 0x17, 0x77),
  

• _INIT_CMD(0x00, 0x18, 0x39),
  

• _INIT_CMD(0x00, 0x19, 0x2D),
  

• _INIT_CMD(0x00, 0x1A, 0x2E),
  

• _INIT_CMD(0x00, 0x1B, 0x32),
  

• _INIT_CMD(0x00, 0x1C, 0x37),
  

• _INIT_CMD(0x00, 0x1D, 0x3A),
  

• _INIT_CMD(0x00, 0x1E, 0x40),
  

• _INIT_CMD(0x00, 0x1F, 0x40),
  

• _INIT_CMD(0x00, 0x20, 0x40),
  

• _INIT_CMD(0x00, 0x21, 0x40),
  

• _INIT_CMD(0x00, 0x22, 0x40),
  

• _INIT_CMD(0x00, 0x23, 0x40),
  

• _INIT_CMD(0x00, 0x24, 0x40),
  

• _INIT_CMD(0x00, 0x25, 0x40),
  

• _INIT_CMD(0x00, 0x26, 0x40),
  

• _INIT_CMD(0x00, 0x27, 0x40),
  

• _INIT_CMD(0x00, 0x28, 0x40),
  

• _INIT_CMD(0x00, 0x2D, 0x00),
  

• _INIT_CMD(0x00, 0x2F, 0x40),
  

• _INIT_CMD(0x00, 0x30, 0x40),
  

• _INIT_CMD(0x00, 0x31, 0x40),
  

• _INIT_CMD(0x00, 0x32, 0x40),
  

• _INIT_CMD(0x00, 0x33, 0x40),
  

• _INIT_CMD(0x00, 0x34, 0x40),
  

• _INIT_CMD(0x00, 0x35, 0x40),
  

• _INIT_CMD(0x00, 0x36, 0x40),
  

• _INIT_CMD(0x00, 0x37, 0x40),
  

• _INIT_CMD(0x00, 0x38, 0x40),
  

• _INIT_CMD(0x00, 0x39, 0x40),
  

• _INIT_CMD(0x00, 0x3A, 0x40),
  

• _INIT_CMD(0x00, 0x3B, 0x40),
  

• _INIT_CMD(0x00, 0x3D, 0x40),
  

• _INIT_CMD(0x00, 0x3F, 0x40),
  

• _INIT_CMD(0x00, 0x40, 0x40),
  

• _INIT_CMD(0x00, 0x41, 0x40),
  

• _INIT_CMD(0x00, 0x42, 0x40),
  

• _INIT_CMD(0x00, 0x43, 0x40),
  

• _INIT_CMD(0x00, 0x44, 0x40),
  

• _INIT_CMD(0x00, 0x45, 0x40),
  

• _INIT_CMD(0x00, 0x46, 0x40),
  

• _INIT_CMD(0x00, 0x47, 0x40),
  

• _INIT_CMD(0x00, 0x48, 0x40),
  

• _INIT_CMD(0x00, 0x49, 0x40),
  

• _INIT_CMD(0x00, 0x4A, 0x40),
  

• _INIT_CMD(0x00, 0x4B, 0x40),
  

• _INIT_CMD(0x00, 0x4C, 0x40),
  

• _INIT_CMD(0x00, 0x4D, 0x40),
  

• _INIT_CMD(0x00, 0x4E, 0x40),
  

• _INIT_CMD(0x00, 0x4F, 0x40),
  

• _INIT_CMD(0x00, 0x50, 0x40),
  

• _INIT_CMD(0x00, 0x51, 0x40),
  

• _INIT_CMD(0x00, 0x52, 0x40),
  

• _INIT_CMD(0x00, 0x53, 0x01),
  

• _INIT_CMD(0x00, 0x54, 0x01),
  

• _INIT_CMD(0x00, 0x55, 0xFE),
  

• _INIT_CMD(0x00, 0x56, 0x77),
  

• _INIT_CMD(0x00, 0x58, 0xCD),
  

• _INIT_CMD(0x00, 0x59, 0xD0),
  

• _INIT_CMD(0x00, 0x5A, 0xD0),
  

• _INIT_CMD(0x00, 0x5B, 0x50),
  

• _INIT_CMD(0x00, 0x5C, 0x50),
  

• _INIT_CMD(0x00, 0x5D, 0x50),
  

• _INIT_CMD(0x00, 0x5E, 0x50),
  

• _INIT_CMD(0x00, 0x5F, 0x50),
  

• _INIT_CMD(0x00, 0x60, 0x50),
  

• _INIT_CMD(0x00, 0x61, 0x50),
  

• _INIT_CMD(0x00, 0x62, 0x50),
  

• _INIT_CMD(0x00, 0x63, 0x50),
  

• _INIT_CMD(0x00, 0x64, 0x50),
  

• _INIT_CMD(0x00, 0x65, 0x50),
  

• _INIT_CMD(0x00, 0x66, 0x50),
  

• _INIT_CMD(0x00, 0x67, 0x50),
  

• _INIT_CMD(0x00, 0x68, 0x50),
  

• _INIT_CMD(0x00, 0x69, 0x50),
  

• _INIT_CMD(0x00, 0x6A, 0x50),
  

• _INIT_CMD(0x00, 0x6B, 0x50),
  

• _INIT_CMD(0x00, 0x6C, 0x50),
  

• _INIT_CMD(0x00, 0x6D, 0x50),
  

• _INIT_CMD(0x00, 0x6E, 0x50),
  

• _INIT_CMD(0x00, 0x6F, 0x50),
  

• _INIT_CMD(0x00, 0x70, 0x07),
  

• _INIT_CMD(0x00, 0x71, 0x00),
  

• _INIT_CMD(0x00, 0x72, 0x00),
  

• _INIT_CMD(0x00, 0x73, 0x00),
  

• _INIT_CMD(0x00, 0x74, 0x06),
  

• _INIT_CMD(0x00, 0x75, 0x0C),
  

• _INIT_CMD(0x00, 0x76, 0x03),
  

• _INIT_CMD(0x00, 0x77, 0x09),
  

• _INIT_CMD(0x00, 0x78, 0x0F),
  

• _INIT_CMD(0x00, 0x79, 0x68),
  

• _INIT_CMD(0x00, 0x7A, 0x88),
  

• _INIT_CMD(0x00, 0x7C, 0x80),
  

• _INIT_CMD(0x00, 0x7D, 0x80),
  

• _INIT_CMD(0x00, 0x7E, 0x80),
  

• _INIT_CMD(0x00, 0x7F, 0x00),
  

• _INIT_CMD(0x00, 0x80, 0x00),
  

• _INIT_CMD(0x00, 0x81, 0x00),
  

• _INIT_CMD(0x00, 0x83, 0x01),
  

• _INIT_CMD(0x00, 0x84, 0x00),
  

• _INIT_CMD(0x00, 0x85, 0x80),
  

• _INIT_CMD(0x00, 0x86, 0x80),
  

• _INIT_CMD(0x00, 0x87, 0x80),
  

• _INIT_CMD(0x00, 0x88, 0x40),
  

• _INIT_CMD(0x00, 0x89, 0x91),
  

• _INIT_CMD(0x00, 0x8A, 0x98),
  

• _INIT_CMD(0x00, 0x8B, 0x80),
  

• _INIT_CMD(0x00, 0x8C, 0x80),
  

• _INIT_CMD(0x00, 0x8D, 0x80),
  

• _INIT_CMD(0x00, 0x8E, 0x80),
  

• _INIT_CMD(0x00, 0x8F, 0x80),
  

• _INIT_CMD(0x00, 0x90, 0x80),
  

• _INIT_CMD(0x00, 0x91, 0x80),
  

• _INIT_CMD(0x00, 0x92, 0x80),
  

• _INIT_CMD(0x00, 0x93, 0x80),
  

• _INIT_CMD(0x00, 0x94, 0x80),
  

• _INIT_CMD(0x00, 0x95, 0x80),
  

• _INIT_CMD(0x00, 0x96, 0x80),
  

• _INIT_CMD(0x00, 0x97, 0x80),
  

• _INIT_CMD(0x00, 0x98, 0x80),
  

• _INIT_CMD(0x00, 0x99, 0x80),
  

• _INIT_CMD(0x00, 0x9A, 0x80),
  

• _INIT_CMD(0x00, 0x9B, 0x80),
  

• _INIT_CMD(0x00, 0x9C, 0x80),
  

• _INIT_CMD(0x00, 0x9D, 0x80),
  

• _INIT_CMD(0x00, 0x9E, 0x80),
  

• _INIT_CMD(0x00, 0x9F, 0x80),
  

• _INIT_CMD(0x00, 0xA0, 0x8A),
  

• _INIT_CMD(0x00, 0xA2, 0x80),
  

• _INIT_CMD(0x00, 0xA6, 0x80),
  

• _INIT_CMD(0x00, 0xA7, 0x80),
  

• _INIT_CMD(0x00, 0xA9, 0x80),
  

• _INIT_CMD(0x00, 0xAA, 0x80),
  

• _INIT_CMD(0x00, 0xAB, 0x80),
  

• _INIT_CMD(0x00, 0xAC, 0x80),
  

• _INIT_CMD(0x00, 0xAD, 0x80),
  

• _INIT_CMD(0x00, 0xAE, 0x80),
  

• _INIT_CMD(0x00, 0xAF, 0x80),
  

• _INIT_CMD(0x00, 0xB7, 0x76),
  

• _INIT_CMD(0x00, 0xB8, 0x76),
  

• _INIT_CMD(0x00, 0xB9, 0x05),
  

• _INIT_CMD(0x00, 0xBA, 0x0D),
  

• _INIT_CMD(0x00, 0xBB, 0x14),
  

• _INIT_CMD(0x00, 0xBC, 0x0F),
  

• _INIT_CMD(0x00, 0xBD, 0x18),
  

• _INIT_CMD(0x00, 0xBE, 0x1F),
  

• _INIT_CMD(0x00, 0xBF, 0x05),
  

• _INIT_CMD(0x00, 0xC0, 0x0D),
  

• _INIT_CMD(0x00, 0xC1, 0x14),
  

• _INIT_CMD(0x00, 0xC2, 0x03),
  

• _INIT_CMD(0x00, 0xC3, 0x07),
  

• _INIT_CMD(0x00, 0xC4, 0x0A),
  

• _INIT_CMD(0x00, 0xC5, 0xA0),
  

• _INIT_CMD(0x00, 0xC6, 0x55),
  

• _INIT_CMD(0x00, 0xC7, 0xFF),
  

• _INIT_CMD(0x00, 0xC8, 0x39),
  

• _INIT_CMD(0x00, 0xC9, 0x44),
  

• _INIT_CMD(0x00, 0xCA, 0x12),
  

• _INIT_CMD(0x00, 0xCD, 0x80),
  

• _INIT_CMD(0x00, 0xDB, 0x80),
  

• _INIT_CMD(0x00, 0xDC, 0x80),
  

• _INIT_CMD(0x00, 0xDD, 0x80),
  

• _INIT_CMD(0x00, 0xE0, 0x80),
  

• _INIT_CMD(0x00, 0xE1, 0x80),
  

• _INIT_CMD(0x00, 0xE2, 0x80),
  

• _INIT_CMD(0x00, 0xE3, 0x80),
  

• _INIT_CMD(0x00, 0xE4, 0x80),
  

• _INIT_CMD(0x00, 0xE5, 0x40),
  

• _INIT_CMD(0x00, 0xE6, 0x40),
  

• _INIT_CMD(0x00, 0xE7, 0x40),
  

• _INIT_CMD(0x00, 0xE8, 0x40),
  

• _INIT_CMD(0x00, 0xE9, 0x40),
  

• _INIT_CMD(0x00, 0xEA, 0x40),
  

• _INIT_CMD(0x00, 0xEB, 0x40),
  

• _INIT_CMD(0x00, 0xEC, 0x40),
  

• _INIT_CMD(0x00, 0xED, 0x40),
  

• _INIT_CMD(0x00, 0xEE, 0x40),
  

• _INIT_CMD(0x00, 0xEF, 0x40),
  

• _INIT_CMD(0x00, 0xF0, 0x40),
  

• _INIT_CMD(0x00, 0xF1, 0x40),
  

• _INIT_CMD(0x00, 0xF2, 0x40),
  

• _INIT_CMD(0x00, 0xF3, 0x40),
  

• _INIT_CMD(0x00, 0xF4, 0x40),
  

• _INIT_CMD(0x00, 0xF5, 0x40),
  

• _INIT_CMD(0x00, 0xF6, 0x40),
  

• _INIT_CMD(0x00, 0xFB, 0x1),
  

• _INIT_CMD(0x00, 0xFF, 0x23),
  

• _INIT_CMD(0x00, 0xFB, 0x01),
  

• /* dimming enable */
  

• _INIT_CMD(0x00, 0x01, 0x84),
  

• _INIT_CMD(0x00, 0x05, 0x2D),
  

• _INIT_CMD(0x00, 0x06, 0x00),
  

•  /* resolution 1080*2246 */
  

• _INIT_CMD(0x00, 0x11, 0x01),
  

• _INIT_CMD(0x00, 0x12, 0x7B),
  

• _INIT_CMD(0x00, 0x15, 0x6F),
  

• _INIT_CMD(0x00, 0x16, 0x0B),
  

•  /* UI mode */
  

• _INIT_CMD(0x00, 0x29, 0x0A),
  

• _INIT_CMD(0x00, 0x30, 0xFF),
  

• _INIT_CMD(0x00, 0x31, 0xFF),
  

• _INIT_CMD(0x00, 0x32, 0xFF),
  

• _INIT_CMD(0x00, 0x33, 0xFF),
  

• _INIT_CMD(0x00, 0x34, 0xFF),
  

• _INIT_CMD(0x00, 0x35, 0xFF),
  

• _INIT_CMD(0x00, 0x36, 0xFF),
  

• _INIT_CMD(0x00, 0x37, 0xFF),
  

• _INIT_CMD(0x00, 0x38, 0xFC),
  

• _INIT_CMD(0x00, 0x39, 0xF8),
  

• _INIT_CMD(0x00, 0x3A, 0xF4),
  

• _INIT_CMD(0x00, 0x3B, 0xF1),
  

• _INIT_CMD(0x00, 0x3D, 0xEE),
  

• _INIT_CMD(0x00, 0x3F, 0xEB),
  

• _INIT_CMD(0x00, 0x40, 0xE8),
  

• _INIT_CMD(0x00, 0x41, 0xE5),
  

•  /* STILL mode */
  

• _INIT_CMD(0x00, 0x2A, 0x13),
  

• _INIT_CMD(0x00, 0x45, 0xFF),
  

• _INIT_CMD(0x00, 0x46, 0xFF),
  

• _INIT_CMD(0x00, 0x47, 0xFF),
  

• _INIT_CMD(0x00, 0x48, 0xFF),
  

• _INIT_CMD(0x00, 0x49, 0xFF),
  

• _INIT_CMD(0x00, 0x4A, 0xFF),
  

• _INIT_CMD(0x00, 0x4B, 0xFF),
  

• _INIT_CMD(0x00, 0x4C, 0xFF),
  

• _INIT_CMD(0x00, 0x4D, 0xED),
  

• _INIT_CMD(0x00, 0x4E, 0xD5),
  

• _INIT_CMD(0x00, 0x4F, 0xBF),
  

• _INIT_CMD(0x00, 0x50, 0xA6),
  

• _INIT_CMD(0x00, 0x51, 0x96),
  

• _INIT_CMD(0x00, 0x52, 0x86),
  

• _INIT_CMD(0x00, 0x53, 0x76),
  

• _INIT_CMD(0x00, 0x54, 0x66),
  

•  /* MOVING mode */
  

• _INIT_CMD(0x00, 0x2B, 0x0E),
  

• _INIT_CMD(0x00, 0x58, 0xFF),
  

• _INIT_CMD(0x00, 0x59, 0xFF),
  

• _INIT_CMD(0x00, 0x5A, 0xFF),
  

• _INIT_CMD(0x00, 0x5B, 0xFF),
  

• _INIT_CMD(0x00, 0x5C, 0xFF),
  

• _INIT_CMD(0x00, 0x5D, 0xFF),
  

• _INIT_CMD(0x00, 0x5E, 0xFF),
  

• _INIT_CMD(0x00, 0x5F, 0xFF),
  

• _INIT_CMD(0x00, 0x60, 0xF6),
  

• _INIT_CMD(0x00, 0x61, 0xEA),
  

• _INIT_CMD(0x00, 0x62, 0xE1),
  

• _INIT_CMD(0x00, 0x63, 0xD8),
  

• _INIT_CMD(0x00, 0x64, 0xCE),
  

• _INIT_CMD(0x00, 0x65, 0xC3),
  

• _INIT_CMD(0x00, 0x66, 0xBA),
  

• _INIT_CMD(0x00, 0x67, 0xB3),
  

• _INIT_CMD(0x00, 0xFF, 0x25),
  

• _INIT_CMD(0x00, 0xFB, 0x01),
  

• _INIT_CMD(0x00, 0x05, 0x04),
  

• _INIT_CMD(0x00, 0xFF, 0x26),
  

• _INIT_CMD(0x00, 0xFB, 0x01),
  

• _INIT_CMD(0x00, 0x1C, 0xAF),
  

• _INIT_CMD(0x00, 0xFF, 0x10),
  

• _INIT_CMD(0x00, 0xFB, 0x01),
  

• _INIT_CMD(0x00, 0x51, 0xFF),
  

• _INIT_CMD(0x00, 0x53, 0x24),
  

• _INIT_CMD(0x00, 0x55, 0x00),
  

• {},
  

+};

+static const struct panel_cmd tianma_fhd_video_on_cmds_2[] = {

• _INIT_CMD(0x00, 0xFF, 0x24),
  

• _INIT_CMD(0x00, 0xFB, 0x01),
  

• _INIT_CMD(0x00, 0xC3, 0x01),
  

• _INIT_CMD(0x00, 0xC4, 0x54),
  

• _INIT_CMD(0x00, 0xFF, 0x10),
  

• {},
  

+};

+static const struct panel_cmd tianma_fhd_video_off_cmds[] = {

• _INIT_CMD(0x00, 0xFF, 0x24),
  

• _INIT_CMD(0x00, 0xFB, 0x01),
  

• _INIT_CMD(0x00, 0xC3, 0x01),
  

• _INIT_CMD(0x00, 0xFF, 0x10),
  

• {},
  

+};

+static const struct drm_display_mode tianma_fhd_video_panel_default_mode = {

• .clock          = 161331,
  

• .hdisplay       = 1080,
  

• .hsync_start    = 1080 + 40,
  

• .hsync_end      = 1080 + 40 + 20,
  

• .htotal         = 1080 + 40 + 20 + 44,
  

• .vdisplay       = 2246,
  

• .vsync_start    = 2246 + 15,
  

• .vsync_end      = 2246 + 15 + 2,
  

• .vtotal         = 2246 + 15 + 2 + 8,
  

• .type = DRM_MODE_TYPE_DRIVER | DRM_MODE_TYPE_PREFERRED,
  

+};

+static const struct panel_desc tianma_fhd_video_panel_desc = {

• .display_mode = &tianma_fhd_video_panel_default_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_1 = tianma_fhd_video_on_cmds_1,
  

• .on_cmds_2 = tianma_fhd_video_on_cmds_2,
  

• .off_cmds = tianma_fhd_video_off_cmds
  

+};

+static int panel_add(struct panel_info *pinfo) +{

• struct device *dev = &pinfo->link->dev;
  

• int i, ret;
  

• for (i = 0; i < ARRAY_SIZE(pinfo->supplies); i++)
  

•         pinfo->supplies[i].supply = regulator_names[i];
  

• ret = devm_regulator_bulk_get(dev, ARRAY_SIZE(pinfo->supplies),
  

•                               pinfo->supplies);
  

• if (ret < 0)
  

•         return ret;
  

Use dev_err_probe() here - so the driver then also support -EPROBE_DEFER correct in this case.

...

• pinfo->reset_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_HIGH);
  

• if (IS_ERR(pinfo->reset_gpio)) {
  

•         DRM_DEV_ERROR(dev, "cannot get reset gpio %ld\n",
  

•                       PTR_ERR(pinfo->reset_gpio));
  

•         return PTR_ERR(pinfo->reset_gpio);
  

• }
  

Use dev_Err_probe() here, thus also fixing that the driver then supports -EPROBE_DEFER.

...

• drm_panel_init(&pinfo->base, dev, &panel_funcs,
  

•                DRM_MODE_CONNECTOR_DSI);
  

• drm_panel_add(&pinfo->base);
  

• return 0;
  

+}

+static int panel_probe(struct mipi_dsi_device *dsi) +{

• struct panel_info *pinfo;
  

• const struct panel_desc *desc;
  

• int err;
  

• pinfo = devm_kzalloc(&dsi->dev, sizeof(*pinfo), GFP_KERNEL);
  

• if (!pinfo)
  

•         return -ENOMEM;
  

• desc = of_device_get_match_data(&dsi->dev);
  

• dsi->mode_flags = desc->mode_flags;
  

• dsi->format = desc->format;
  

• dsi->lanes = desc->lanes;
  

• pinfo->desc = desc;
  

• pinfo->link = dsi;
  

• mipi_dsi_set_drvdata(dsi, pinfo);
  

• err = panel_add(pinfo);
  

• if (err < 0)
  

•         return err;
  

• return mipi_dsi_attach(dsi);
  

+}

+static int panel_remove(struct mipi_dsi_device *dsi) +{

• struct panel_info *pinfo = mipi_dsi_get_drvdata(dsi);
  

• int err;
  

• err = drm_panel_unprepare(&pinfo->base);
  

• if (err < 0)
  

•         DRM_DEV_ERROR(&dsi->dev, "failed to unprepare panel: %d\n",
  

•                       err);
  

• err = drm_panel_disable(&pinfo->base);
  

• if (err < 0)
  

•         DRM_DEV_ERROR(&dsi->dev, "failed to disable panel: %d\n", err);
  

• err = mipi_dsi_detach(dsi);
  

• if (err < 0)
  

•         DRM_DEV_ERROR(&dsi->dev, "failed to detach from DSI host: %d\n",
  

•                       err);
  

• drm_panel_remove(&pinfo->base);
  

• return 0;
  

+}

+static void panel_shutdown(struct mipi_dsi_device *dsi) +{

• struct panel_info *pinfo = mipi_dsi_get_drvdata(dsi);
  

• drm_panel_disable(&pinfo->base);
  

• drm_panel_unprepare(&pinfo->base);
  

+}

+static const struct of_device_id tianma_fhd_video_of_match[] = {

• { .compatible = "tianma,fhd-video",
  

•   .data = &tianma_fhd_video_panel_desc
  

• },
  

• {
  

•         /* sentinel */
  

• }
  

+}; +MODULE_DEVICE_TABLE(of, tianma_fhd_video_of_match);

+static struct mipi_dsi_driver panel_driver = {

• .driver = {
  

•         .name = "panel-tianma-nt36672a",
  

•         .of_match_table = tianma_fhd_video_of_match,
  

• },
  

• .probe = panel_probe,
  

• .remove = panel_remove,
  

• .shutdown = panel_shutdown,
  

+}; +module_mipi_dsi_driver(panel_driver);

+MODULE_AUTHOR("Sumit Semwal sumit.semwal@linaro.org"); +MODULE_DESCRIPTION("NOVATEK NT36672A based MIPI-DSI LCD panel driver");

+MODULE_LICENSE("GPL");

2.28.0

Best, Sumit.