Hi Shawn, Thanks for the patch! On Wed, Aug 04, 2021 at 04:13:52PM +0800, Shawn Guo wrote: > It adds a drm driver for Truly NT35521 5.24" 1280x720 DSI panel, which > can be found on Sony Xperia M4 Aqua phone. The panel backlight is > managed through DSI link. > > Signed-off-by: Shawn Guo <shawn.guo@xxxxxxxxxx> > --- > drivers/gpu/drm/panel/Kconfig | 9 + > drivers/gpu/drm/panel/Makefile | 1 + > drivers/gpu/drm/panel/panel-truly-nt35521.c | 491 ++++++++++++++++++++ > 3 files changed, 501 insertions(+) > create mode 100644 drivers/gpu/drm/panel/panel-truly-nt35521.c > > diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig > index ef87d92cdf49..cdc4abd5c40c 100644 > --- a/drivers/gpu/drm/panel/Kconfig > +++ b/drivers/gpu/drm/panel/Kconfig > @@ -537,6 +537,15 @@ config DRM_PANEL_TPO_TPG110 > 400CH LTPS TFT LCD Single Chip Digital Driver for up to > 800x400 LCD panels. > > +config DRM_PANEL_TRULY_NT35521 > + tristate "Truly NT35521 panel" I think the name "Truly NT35521" is a bit too generic. AFAIK "Truly" is a panel vendor and the NovaTek NT35521 is the panel controller. But there are almost certainly other Truly panels that were also combined with a NT35521 but need a slightly different configuration. If you don't know more than "Truly NT35521" based on the Sony sources, maybe do it similar to "asus,z00t-tm5p5-n35596" and use a compatible like "sony,<device>-truly-nt35521". Would be good to clarify the Kconfig option here too. > + depends on OF > + depends on DRM_MIPI_DSI > + depends on BACKLIGHT_CLASS_DEVICE > + help > + Say Y here if you want to enable support for Truly NT35521 > + 1280x720 DSI panel. > + > config DRM_PANEL_TRULY_NT35597_WQXGA > tristate "Truly WQXGA" > depends on OF > diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile > index cae4d976c069..3d3c98cb7a7b 100644 > --- a/drivers/gpu/drm/panel/Makefile > +++ b/drivers/gpu/drm/panel/Makefile > @@ -56,6 +56,7 @@ obj-$(CONFIG_DRM_PANEL_TDO_TL070WSH30) += panel-tdo-tl070wsh30.o > obj-$(CONFIG_DRM_PANEL_TPO_TD028TTEC1) += panel-tpo-td028ttec1.o > obj-$(CONFIG_DRM_PANEL_TPO_TD043MTEA1) += panel-tpo-td043mtea1.o > obj-$(CONFIG_DRM_PANEL_TPO_TPG110) += panel-tpo-tpg110.o > +obj-$(CONFIG_DRM_PANEL_TRULY_NT35521) += panel-truly-nt35521.o > obj-$(CONFIG_DRM_PANEL_TRULY_NT35597_WQXGA) += panel-truly-nt35597.o > obj-$(CONFIG_DRM_PANEL_VISIONOX_RM69299) += panel-visionox-rm69299.o > obj-$(CONFIG_DRM_PANEL_XINPENG_XPP055C272) += panel-xinpeng-xpp055c272.o > diff --git a/drivers/gpu/drm/panel/panel-truly-nt35521.c b/drivers/gpu/drm/panel/panel-truly-nt35521.c > new file mode 100644 > index 000000000000..ea3cfb46be7e > --- /dev/null > +++ b/drivers/gpu/drm/panel/panel-truly-nt35521.c > @@ -0,0 +1,491 @@ > +// SPDX-License-Identifier: GPL-2.0 > +/* > + * Copyright (c) 2021, Linaro Limited > + */ > + > +#include <linux/backlight.h> > +#include <linux/delay.h> > +#include <linux/gpio/consumer.h> > +#include <linux/module.h> > + > +#include <video/mipi_display.h> > + > +#include <drm/drm_mipi_dsi.h> > +#include <drm/drm_modes.h> > +#include <drm/drm_panel.h> > +#include <drm/drm_print.h> > + > +struct nt35521_panel { > + struct drm_panel panel; > + struct device *dev; > + struct gpio_desc *rst_gpio; > + struct gpio_desc *pwrp5_gpio; > + struct gpio_desc *pwrn5_gpio; > + struct gpio_desc *en_gpio; > + bool prepared; > + bool enabled; > +}; > + > +static inline struct nt35521_panel *panel_to_nt35521(struct drm_panel *panel) > +{ > + return container_of(panel, struct nt35521_panel, panel); > +} > + > +#define nt_dcs_write(seq...) \ > +({ \ > + const u8 d[] = { seq }; \ > + if (mipi_dsi_dcs_write_buffer(dsi, d, ARRAY_SIZE(d)) < 0) \ > + DRM_DEV_ERROR(dev, "dcs write buffer failed\n"); \ > +}) > + > +#define nt_gen_write(seq...) \ > +({ \ > + const u8 d[] = { seq }; \ > + if (mipi_dsi_generic_write(dsi, d, ARRAY_SIZE(d)) < 0) \ > + DRM_DEV_ERROR(dev, "generic write buffer failed\n"); \ > +}) > + > +static void nt35521_panel_on(struct nt35521_panel *nt) > +{ > + struct mipi_dsi_device *dsi = to_mipi_dsi_device(nt->dev); > + struct device *dev = nt->dev; > + > + /* Transmit data in low power mode */ > + dsi->mode_flags |= MIPI_DSI_MODE_LPM; > + > + nt_dcs_write(0xf0, 0x55, 0xaa, 0x52, 0x08, 0x00); > + nt_dcs_write(0xff, 0xaa, 0x55, 0xa5, 0x80); > + nt_dcs_write(0x6f, 0x11, 0x00); > + nt_dcs_write(0xf7, 0x20, 0x00); > + nt_dcs_write(0x6f, 0x01); > + nt_dcs_write(0xb1, 0x21); > + nt_dcs_write(0xbd, 0x01, 0xa0, 0x10, 0x08, 0x01); > + nt_dcs_write(0xb8, 0x01, 0x02, 0x0c, 0x02); > + nt_dcs_write(0xbb, 0x11, 0x11); > + nt_dcs_write(0xbc, 0x00, 0x00); > + nt_dcs_write(0xb6, 0x02); > + nt_dcs_write(0xf0, 0x55, 0xaa, 0x52, 0x08, 0x01); > + nt_dcs_write(0xb0, 0x09, 0x09); > + nt_dcs_write(0xb1, 0x09, 0x09); > + nt_dcs_write(0xbc, 0x8c, 0x00); > + nt_dcs_write(0xbd, 0x8c, 0x00); > + nt_dcs_write(0xca, 0x00); > + nt_dcs_write(0xc0, 0x04); > + nt_dcs_write(0xbe, 0xb5); > + nt_dcs_write(0xb3, 0x35, 0x35); > + nt_dcs_write(0xb4, 0x25, 0x25); > + nt_dcs_write(0xb9, 0x43, 0x43); > + nt_dcs_write(0xba, 0x24, 0x24); > + nt_dcs_write(0xf0, 0x55, 0xaa, 0x52, 0x08, 0x02); > + nt_dcs_write(0xee, 0x03); > + nt_dcs_write(0xb0, 0x00, 0xb2, 0x00, 0xb3, 0x00, 0xb6, 0x00, > + 0xc3, 0x00, 0xce, 0x00, 0xe1, 0x00, 0xf3, 0x01, > + 0x11); > + nt_dcs_write(0xb1, 0x01, 0x2e, 0x01, 0x5c, 0x01, 0x82, 0x01, > + 0xc3, 0x01, 0xfe, 0x02, 0x00, 0x02, 0x37, 0x02, > + 0x77); > + nt_dcs_write(0xb2, 0x02, 0xa1, 0x02, 0xd7, 0x02, 0xfe, 0x03, > + 0x2c, 0x03, 0x4b, 0x03, 0x63, 0x03, 0x8f, 0x03, > + 0x90); > + nt_dcs_write(0xb3, 0x03, 0x96, 0x03, 0x98); > + nt_dcs_write(0xb4, 0x00, 0x81, 0x00, 0x8b, 0x00, 0x9c, 0x00, > + 0xa9, 0x00, 0xb5, 0x00, 0xcb, 0x00, 0xdf, 0x01, > + 0x02); > + nt_dcs_write(0xb5, 0x01, 0x1f, 0x01, 0x51, 0x01, 0x7a, 0x01, > + 0xbf, 0x01, 0xfa, 0x01, 0xfc, 0x02, 0x34, 0x02, 0x76); > + nt_dcs_write(0xb6, 0x02, 0x9f, 0x02, 0xd7, 0x02, 0xfc, 0x03, 0x2c, > + 0x03, 0x4a, 0x03, 0x63, 0x03, 0x8f, 0x03, 0xa2); > + nt_dcs_write(0xb7, 0x03, 0xb8, 0x03, 0xba); > + nt_dcs_write(0xb8, 0x00, 0x01, 0x00, 0x02, 0x00, 0x0e, 0x00, 0x2a, > + 0x00, 0x41, 0x00, 0x67, 0x00, 0x87, 0x00, 0xb9); > + nt_dcs_write(0xb9, 0x00, 0xe2, 0x01, 0x22, 0x01, 0x54, 0x01, 0xa3, > + 0x01, 0xe6, 0x01, 0xe7, 0x02, 0x24, 0x02, 0x67); > + nt_dcs_write(0xba, 0x02, 0x93, 0x02, 0xcd, 0x02, 0xf6, 0x03, 0x31, > + 0x03, 0x6c, 0x03, 0xe9, 0x03, 0xef, 0x03, 0xf4); > + nt_dcs_write(0xbb, 0x03, 0xf6, 0x03, 0xf7); > + nt_dcs_write(0xf0, 0x55, 0xaa, 0x52, 0x08, 0x03); > + nt_dcs_write(0xb0, 0x22, 0x00); > + nt_dcs_write(0xb1, 0x22, 0x00); > + nt_dcs_write(0xb2, 0x05, 0x00, 0x60, 0x00, 0x00); > + nt_dcs_write(0xb3, 0x05, 0x00, 0x60, 0x00, 0x00); > + nt_dcs_write(0xb4, 0x05, 0x00, 0x60, 0x00, 0x00); > + nt_dcs_write(0xb5, 0x05, 0x00, 0x60, 0x00, 0x00); > + nt_dcs_write(0xba, 0x53, 0x00, 0x60, 0x00, 0x00); > + nt_dcs_write(0xbb, 0x53, 0x00, 0x60, 0x00, 0x00); > + nt_dcs_write(0xbc, 0x53, 0x00, 0x60, 0x00, 0x00); > + nt_dcs_write(0xbd, 0x53, 0x00, 0x60, 0x00, 0x00); > + nt_dcs_write(0xc0, 0x00, 0x34, 0x00, 0x00); > + nt_dcs_write(0xc1, 0x00, 0x00, 0x34, 0x00); > + nt_dcs_write(0xc2, 0x00, 0x00, 0x34, 0x00); > + nt_dcs_write(0xc3, 0x00, 0x00, 0x34, 0x00); > + nt_dcs_write(0xc4, 0x60); > + nt_dcs_write(0xc5, 0xc0); > + nt_dcs_write(0xc6, 0x00); > + nt_dcs_write(0xc7, 0x00); > + nt_dcs_write(0xf0, 0x55, 0xaa, 0x52, 0x08, 0x05); > + nt_dcs_write(0xb0, 0x17, 0x06); > + nt_dcs_write(0xb1, 0x17, 0x06); > + nt_dcs_write(0xb2, 0x17, 0x06); > + nt_dcs_write(0xb3, 0x17, 0x06); > + nt_dcs_write(0xb4, 0x17, 0x06); > + nt_dcs_write(0xb5, 0x17, 0x06); > + nt_dcs_write(0xb6, 0x17, 0x06); > + nt_dcs_write(0xb7, 0x17, 0x06); > + nt_dcs_write(0xb8, 0x00); > + nt_dcs_write(0xb9, 0x00, 0x03); > + nt_dcs_write(0xba, 0x00, 0x00); > + nt_dcs_write(0xbb, 0x02, 0x03); > + nt_dcs_write(0xbc, 0x02, 0x03); > + nt_dcs_write(0xbd, 0x03, 0x03, 0x00, 0x03, 0x03); > + nt_dcs_write(0xc0, 0x0b); > + nt_dcs_write(0xc1, 0x09); > + nt_dcs_write(0xc2, 0xa6); > + nt_dcs_write(0xc3, 0x05); > + nt_dcs_write(0xc4, 0x00); > + nt_dcs_write(0xc5, 0x02); > + nt_dcs_write(0xc6, 0x22); > + nt_dcs_write(0xc7, 0x03); > + nt_dcs_write(0xc8, 0x07, 0x20); > + nt_dcs_write(0xc9, 0x03, 0x20); > + nt_dcs_write(0xca, 0x01, 0x60); > + nt_dcs_write(0xcb, 0x01, 0x60); > + nt_dcs_write(0xcc, 0x00, 0x00, 0x02); > + nt_dcs_write(0xcd, 0x00, 0x00, 0x02); > + nt_dcs_write(0xce, 0x00, 0x00, 0x02); > + nt_dcs_write(0xcf, 0x00, 0x00, 0x02); > + nt_dcs_write(0xd1, 0x00, 0x05, 0x01, 0x07, 0x10); > + nt_dcs_write(0xd2, 0x10, 0x05, 0x05, 0x03, 0x10); > + nt_dcs_write(0xd3, 0x20, 0x00, 0x43, 0x07, 0x10); > + nt_dcs_write(0xd4, 0x30, 0x00, 0x43, 0x07, 0x10); > + nt_dcs_write(0xd0, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00); > + nt_dcs_write(0xd5, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, > + 0x00, 0x00, 0x00, 0x00); > + nt_dcs_write(0xd6, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, > + 0x00, 0x00, 0x00, 0x00); > + nt_dcs_write(0xd7, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, > + 0x00, 0x00, 0x00, 0x00); > + nt_dcs_write(0xd8, 0x00, 0x00, 0x00, 0x00, 0x00); > + nt_dcs_write(0xe5, 0x06); > + nt_dcs_write(0xe6, 0x06); > + nt_dcs_write(0xe7, 0x00); > + nt_dcs_write(0xe8, 0x06); > + nt_dcs_write(0xe9, 0x06); > + nt_dcs_write(0xea, 0x06); > + nt_dcs_write(0xeb, 0x00); > + nt_dcs_write(0xec, 0x00); > + nt_dcs_write(0xed, 0x30); > + nt_dcs_write(0xf0, 0x55, 0xaa, 0x52, 0x08, 0x06); > + nt_dcs_write(0xb0, 0x31, 0x31); > + nt_dcs_write(0xb1, 0x31, 0x31); > + nt_dcs_write(0xb2, 0x2d, 0x2e); > + nt_dcs_write(0xb3, 0x31, 0x34); > + nt_dcs_write(0xb4, 0x29, 0x2a); > + nt_dcs_write(0xb5, 0x12, 0x10); > + nt_dcs_write(0xb6, 0x18, 0x16); > + nt_dcs_write(0xb7, 0x00, 0x02); > + nt_dcs_write(0xb8, 0x08, 0x31); > + nt_dcs_write(0xb9, 0x31, 0x31); > + nt_dcs_write(0xba, 0x31, 0x31); > + nt_dcs_write(0xbb, 0x31, 0x08); > + nt_dcs_write(0xbc, 0x03, 0x01); > + nt_dcs_write(0xbd, 0x17, 0x19); > + nt_dcs_write(0xbe, 0x11, 0x13); > + nt_dcs_write(0xbf, 0x2a, 0x29); > + nt_dcs_write(0xc0, 0x34, 0x31); > + nt_dcs_write(0xc1, 0x2e, 0x2d); > + nt_dcs_write(0xc2, 0x31, 0x31); > + nt_dcs_write(0xc3, 0x31, 0x31); > + nt_dcs_write(0xc4, 0x31, 0x31); > + nt_dcs_write(0xc5, 0x31, 0x31); > + nt_dcs_write(0xc6, 0x2e, 0x2d); > + nt_dcs_write(0xc7, 0x31, 0x34); > + nt_dcs_write(0xc8, 0x29, 0x2a); > + nt_dcs_write(0xc9, 0x17, 0x19); > + nt_dcs_write(0xca, 0x11, 0x13); > + nt_dcs_write(0xcb, 0x03, 0x01); > + nt_dcs_write(0xcc, 0x08, 0x31); > + nt_dcs_write(0xcd, 0x31, 0x31); > + nt_dcs_write(0xce, 0x31, 0x31); > + nt_dcs_write(0xcf, 0x31, 0x08); > + nt_dcs_write(0xd0, 0x00, 0x02); > + nt_dcs_write(0xd1, 0x12, 0x10); > + nt_dcs_write(0xd2, 0x18, 0x16); > + nt_dcs_write(0xd3, 0x2a, 0x29); > + nt_dcs_write(0xd4, 0x34, 0x31); > + nt_dcs_write(0xd5, 0x2d, 0x2e); > + nt_dcs_write(0xd6, 0x31, 0x31); > + nt_dcs_write(0xd7, 0x31, 0x31); > + nt_dcs_write(0xe5, 0x31, 0x31); > + nt_dcs_write(0xe6, 0x31, 0x31); > + nt_dcs_write(0xd8, 0x00, 0x00, 0x00, 0x00, 0x00); > + nt_dcs_write(0xd9, 0x00, 0x00, 0x00, 0x00, 0x00); > + nt_dcs_write(0xe7, 0x00); > + nt_dcs_write(0x6f, 0x02); > + nt_dcs_write(0xf7, 0x47); > + nt_dcs_write(0x6f, 0x0a); > + nt_dcs_write(0xf7, 0x02); > + nt_dcs_write(0x6f, 0x17); > + nt_dcs_write(0xf4, 0x60); > + nt_dcs_write(0x6f, 0x01); > + nt_dcs_write(0xf9, 0x46); > + nt_dcs_write(0x6f, 0x11); > + nt_dcs_write(0xf3, 0x01); > + nt_dcs_write(0x35, 0x00); > + nt_dcs_write(0xf0, 0x55, 0xaa, 0x52, 0x08, 0x00); > + nt_dcs_write(0xd9, 0x02, 0x03, 0x00); > + nt_dcs_write(0xf0, 0x55, 0xaa, 0x52, 0x00, 0x00); > + nt_dcs_write(0xf0, 0x55, 0xaa, 0x52, 0x08, 0x00); > + nt_dcs_write(0xb1, 0x6c, 0x21); > + nt_dcs_write(0xf0, 0x55, 0xaa, 0x52, 0x00, 0x00); > + nt_dcs_write(0x35, 0x00); > + nt_gen_write(0x11, 0x00); > + msleep(120); > + nt_gen_write(0x29, 0x00); > + usleep_range(1000, 1500); > + nt_dcs_write(0x53, 0x24); Did you mix up "nt_dcs_write" and "nt_gen_write" here? The nt_gen_write(0x11, 0x00); looks like MIPI_DCS_EXIT_SLEEP_MODE and the nt_gen_write(0x29, 0x00); looks like MIPI_DCS_SET_DISPLAY_ON. For reference you can pull your original reference DTB from Sony through my panel driver generator: https://github.com/msm8916-mainline/linux-mdss-dsi-panel-driver-generator It produces the following (I compiled "msm8939-kanuti_tulip.dtb" from https://github.com/sonyxperiadev/kernel/tree/aosp/LA.BR.1.3.3_rb2.14, not sure if that is right): // ... dsi_generic_write_seq(dsi, 0x35, 0x00); ret = mipi_dsi_dcs_exit_sleep_mode(dsi); if (ret < 0) { dev_err(dev, "Failed to exit sleep mode: %d\n", ret); return ret; } msleep(120); ret = mipi_dsi_dcs_set_display_on(dsi); if (ret < 0) { dev_err(dev, "Failed to set display on: %d\n", ret); return ret; } usleep_range(1000, 2000); dsi_generic_write_seq(dsi, 0x53, 0x24); Which also suggests that generic and DCS writes are mixed up here. Note however that you could not use the generated driver as-is, because Sony seems to use their own display driver instead of Qualcomm's and some things seem to be different. > +} > + > +static void nt35521_panel_off(struct nt35521_panel *nt) > +{ > + struct mipi_dsi_device *dsi = to_mipi_dsi_device(nt->dev); > + struct device *dev = nt->dev; > + > + /* Transmit data in high speed mode */ > + dsi->mode_flags &= ~MIPI_DSI_MODE_LPM; > + > + nt_dcs_write(0x28, 0x00); > + msleep(50); > + nt_dcs_write(0x10, 0x00); > + msleep(150); A bit more deobfuscated from the panel driver generator: dsi->mode_flags &= ~MIPI_DSI_MODE_LPM; ret = mipi_dsi_dcs_set_display_off(dsi); if (ret < 0) { dev_err(dev, "Failed to set display off: %d\n", ret); return ret; } msleep(50); ret = mipi_dsi_dcs_enter_sleep_mode(dsi); if (ret < 0) { dev_err(dev, "Failed to enter sleep mode: %d\n", ret); return ret; } msleep(150); (I'm mainly referring to the mipi_dsi_dcs_*() here instead of the magic numbers...) > +} > + > +static int nt35521_prepare(struct drm_panel *panel) > +{ > + struct nt35521_panel *nt = panel_to_nt35521(panel); > + > + if (nt->prepared) > + return 0; > + > + gpiod_set_value_cansleep(nt->pwrp5_gpio, 1); > + usleep_range(1000, 1500); > + gpiod_set_value_cansleep(nt->pwrn5_gpio, 1); > + usleep_range(10000, 15000); > + gpiod_set_value_cansleep(nt->rst_gpio, 0); > + msleep(150); > + > + nt35521_panel_on(nt); > + > + nt->prepared = true; > + > + return 0; > +} > + > +static int nt35521_unprepare(struct drm_panel *panel) > +{ > + struct nt35521_panel *nt = panel_to_nt35521(panel); > + > + if (!nt->prepared) > + return 0; > + > + nt35521_panel_off(nt); > + > + gpiod_set_value_cansleep(nt->rst_gpio, 1); > + > + nt->prepared = false; > + > + return 0; > +} > + > +static int nt35521_enable(struct drm_panel *panel) > +{ > + struct nt35521_panel *nt = panel_to_nt35521(panel); > + > + if (nt->enabled) > + return 0; > + > + gpiod_set_value_cansleep(nt->en_gpio, 1); > + > + nt->enabled = true; > + > + return 0; > +} > + > +static int nt35521_disable(struct drm_panel *panel) > +{ > + struct nt35521_panel *nt = panel_to_nt35521(panel); > + > + if (!nt->enabled) > + return 0; > + > + gpiod_set_value_cansleep(nt->en_gpio, 0); > + > + nt->enabled = false; > + > + return 0; > +} > + > +static const struct drm_display_mode nt35521_modes = { > + .clock = 133306, > + .hdisplay = 720, > + .hsync_start = 720 + 632, > + .hsync_end = 720 + 632 + 40, > + .htotal = 720 + 632 + 40 + 295, > + .vdisplay = 1280, > + .vsync_start = 1280 + 18, > + .vsync_end = 1280 + 18 + 1, > + .vtotal = 1280 + 18 + 1 + 18, > +}; > + > +static int nt35521_get_modes(struct drm_panel *panel, > + struct drm_connector *connector) > +{ > + struct nt35521_panel *nt = panel_to_nt35521(panel); > + struct drm_display_mode *mode; > + > + mode = drm_mode_duplicate(connector->dev, &nt35521_modes); > + if (!mode) { > + DRM_DEV_ERROR(nt->dev, "failed to add display mode\n"); > + return -ENOMEM; > + } > + > + drm_mode_set_name(mode); > + drm_mode_probed_add(connector, mode); > + > + connector->display_info.width_mm = 65; > + connector->display_info.height_mm = 116; > + > + return 1; > +} > + > +static const struct drm_panel_funcs nt35521_drm_funcs = { > + .prepare = nt35521_prepare, > + .unprepare = nt35521_unprepare, > + .enable = nt35521_enable, > + .disable = nt35521_disable, > + .get_modes = nt35521_get_modes, > +}; > + > +static int nt35521_backlight_update_status(struct backlight_device *bd) > +{ > + struct nt35521_panel *nt = bl_get_data(bd); > + struct mipi_dsi_device *dsi = to_mipi_dsi_device(nt->dev); > + u8 brightness = bd->props.brightness; u8 brightness = backlight_get_brightness(bl); Is preferred now I think(?). > + int ret; > + > + ret = mipi_dsi_dcs_write(dsi, MIPI_DCS_SET_DISPLAY_BRIGHTNESS, > + &brightness, > + sizeof(brightness)); Does this work too? ret = mipi_dsi_dcs_set_display_brightness(dsi, brightness); > + if (ret < 0) > + return ret; > + > + return 0; > +} > + > +static const struct backlight_ops nt35521_backlight_ops = { > + .update_status = nt35521_backlight_update_status, > +}; > + > +static int nt35521_probe(struct mipi_dsi_device *dsi) > +{ > + struct backlight_properties props; > + struct device *dev = &dsi->dev; > + struct nt35521_panel *nt; > + int ret; > + > + nt = devm_kzalloc(dev, sizeof(*nt), GFP_KERNEL); > + if (!nt) > + return -ENOMEM; > + > + nt->rst_gpio = devm_gpiod_get(dev, "reset", GPIOD_OUT_LOW); > + if (IS_ERR(nt->rst_gpio)) { > + ret = PTR_ERR(nt->rst_gpio); > + DRM_DEV_ERROR(dev, "failed to get reset GPIO: %d\n", ret); > + return ret; > + } > + > + nt->pwrp5_gpio = devm_gpiod_get(dev, "pwr-positive5", GPIOD_OUT_LOW); > + if (IS_ERR(nt->pwrp5_gpio)) { > + ret = PTR_ERR(nt->pwrp5_gpio); > + DRM_DEV_ERROR(dev, "failed to get positive5 GPIO: %d\n", ret); > + return ret; > + } > + > + nt->pwrn5_gpio = devm_gpiod_get(dev, "pwr-negative5", GPIOD_OUT_LOW); > + if (IS_ERR(nt->pwrn5_gpio)) { > + ret = PTR_ERR(nt->pwrn5_gpio); > + DRM_DEV_ERROR(dev, "failed to get negative5 GPIO: %d\n", ret); > + return ret; > + } > + These two GPIOs look a lot like typical 5V display regulators that would be better described through the regulator subsystem. You can declare them as fixed-regulator to toggle the GPIO. > + nt->en_gpio = devm_gpiod_get(dev, "enable", GPIOD_OUT_LOW); > + if (IS_ERR(nt->en_gpio)) { > + ret = PTR_ERR(nt->en_gpio); > + DRM_DEV_ERROR(dev, "failed to get enable GPIO: %d\n", ret); > + return ret; > + } Does this refer to the "platform-bklight-en-gpio" in the Sony sources? Perhaps calling it "backlight-gpios" or something like that would be more clear to show that it's related to the backlight. Thanks! Stephan