On Sat, Feb 14, 2026 at 5:21 PM Archit Anant <[email protected]> wrote: > > Add a DRM driver for Sitronix ST7789V display controllers using the > mipi_dbi interface. > > Currently, support for this controller is split between a legacy fbdev > driver in staging (fb_st7789v.c) and a DRM panel driver that requires > 9-bit SPI words (panel-sitronix-st7789v.c). This new driver uses the > mipi_dbi helper to support standard 8-bit SPI with a D/C GPIO, which > is the configuration used by the vast majority of hobbyist and > embedded hardware.
Notes about this below. > > The initialization sequence is ported from the staging driver and > supports several panels: > - Generic 240x320 profile > - HannStar HSD20 IPS > - Inanbo T28CP45TN89-V17 > - EDT ET028013DMA > - Jasonic JT240MHQS-HWT-EK-E3 First of all, please run scripts/checkpatch.pl on patches before you send them. The indentation is all wrong. The script would have caught it. And check out Documentation/process/submitting-patches.rst for any other steps you should do before submitting patches. > Signed-off-by: Archit Anant <[email protected]> > --- > drivers/gpu/drm/sitronix/Kconfig | 17 ++ > drivers/gpu/drm/sitronix/Makefile | 2 + > drivers/gpu/drm/sitronix/st7789v.c | 307 +++++++++++++++++++++++++++++ > 3 files changed, 326 insertions(+) > create mode 100644 drivers/gpu/drm/sitronix/st7789v.c > > diff --git a/drivers/gpu/drm/sitronix/Kconfig > b/drivers/gpu/drm/sitronix/Kconfig > index 6de7d92d9b74..7a2c66677003 100644 > --- a/drivers/gpu/drm/sitronix/Kconfig > +++ b/drivers/gpu/drm/sitronix/Kconfig > @@ -40,3 +40,20 @@ config DRM_ST7735R > > If M is selected the module will be called st7735r. > > +config DRM_ST7789V > + tristate "DRM support for Sitronix ST7789V display panels" > + depends on DRM && SPI > + select DRM_CLIENT_SELECTION > + select DRM_GEM_DMA_HELPER > + select DRM_KMS_HELPER > + select DRM_MIPI_DBI > + select BACKLIGHT_CLASS_DEVICE > + help > + DRM driver for Sitronix ST7789V panels connected via SPI. > + This driver supports several panels including: > + * HannStar HSD20 IPS > + * Inanbo T28CP45TN89-V17 > + * EDT ET028013DMA > + * Jasonic JT240MHQS-HWT-EK-E3 > + > + If M is selected the module will be called st7789v. > diff --git a/drivers/gpu/drm/sitronix/Makefile > b/drivers/gpu/drm/sitronix/Makefile > index bd139e5a6995..96b2a4d85368 100644 > --- a/drivers/gpu/drm/sitronix/Makefile > +++ b/drivers/gpu/drm/sitronix/Makefile > @@ -1,3 +1,5 @@ > obj-$(CONFIG_DRM_ST7571_I2C) += st7571-i2c.o > obj-$(CONFIG_DRM_ST7586) += st7586.o > obj-$(CONFIG_DRM_ST7735R) += st7735r.o > +obj-$(CONFIG_DRM_ST7789V) += st7789v.o > + Empty line not needed. > diff --git a/drivers/gpu/drm/sitronix/st7789v.c > b/drivers/gpu/drm/sitronix/st7789v.c > new file mode 100644 > index 000000000000..4ce4b46d8df2 > --- /dev/null > +++ b/drivers/gpu/drm/sitronix/st7789v.c > @@ -0,0 +1,307 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * DRM driver for Sitronix ST7789V LCD panels > + * > + * Copyright (C) 2026 Archit Anant <[email protected]> > + */ > + > +#include <linux/bits.h> > +#include <linux/module.h> > +#include <linux/kernel.h> > +#include <linux/spi/spi.h> > +#include <linux/gpio/consumer.h> > +#include <linux/delay.h> > +#include <linux/backlight.h> Sort this group alphabetically. > + > +#include <drm/drm_device.h> > +#include <drm/drm_drv.h> > +#include <drm/drm_managed.h> > +#include <drm/drm_mipi_dbi.h> > +#include <drm/drm_modes.h> > +#include <drm/drm_gem_dma_helper.h> > +#include <drm/drm_atomic_helper.h> > +#include <drm/clients/drm_client_setup.h> > +#include <drm/drm_fbdev_dma.h> Sort this group alphabetically. And add an empty line here for group separation. > +#include <video/mipi_display.h> > + > +#define ST7789V_PORCTRL 0xb2 > +#define ST7789V_GCTRL 0xb7 > +#define ST7789V_VCOMS 0xbb > +#define ST7789V_LCMCTRL 0xc0 > +#define ST7789V_VDVVRHEN 0xc2 > +#define ST7789V_VRHS 0xc3 > +#define ST7789V_VDVS 0xc4 > +#define ST7789V_VCMOFSET 0xc5 > +#define ST7789V_FRCTRL2 0xc6 > +#define ST7789V_PWCTRL1 0xd0 > +#define ST7789V_PVGAMCTRL 0xe0 > +#define ST7789V_NVGAMCTRL 0xe1 > + > +#define ST7789V_MADCTL_MY BIT(7) > +#define ST7789V_MADCTL_MX BIT(6) > +#define ST7789V_MADCTL_MV BIT(5) > +#define ST7789V_MADCTL_BGR BIT(3) > + > + > +struct st7789v_cfg { > + const struct drm_display_mode mode; > + unsigned int left_offset; > + unsigned int top_offset; > + bool is_ips; /* Controls PORCTRL and GCTRL timings */ > + bool invert; /* Controls Color Inversion (positive/negative) */ > +}; > +struct st7789v_priv { > + struct mipi_dbi_dev dbidev; /* Must be first for .release() */ > + const struct st7789v_cfg *cfg; > +}; > + > + > +/* 1. Generic Fallback (Matches default behavior of fb_st7789v.c) */ > +static const struct st7789v_cfg generic_cfg = { > + .mode = { DRM_SIMPLE_MODE(240, 320, 0, 0) }, > + .is_ips = false, > + .invert = true, > +}; > + > +/* 2. HannStar 2.0" IPS (The specific panel handled in staging) */ > +static const struct st7789v_cfg hsd20_ips_cfg = { > + .mode = { DRM_SIMPLE_MODE(240, 320, 31, 41) }, > + .is_ips = true, > + .invert = true, > +}; > + > +/* 3. Inanbo 2.8" (From the 9-bit driver: No Inversion) */ > +static const struct st7789v_cfg inanbo_panel_cfg = { > + .mode = { DRM_SIMPLE_MODE(240, 320, 43, 57) }, > + .is_ips = false, > + .invert = false, > +}; > + > +/* 4. EDT 2.8" (From the 9-bit driver: Normal Inversion) */ > +static const struct st7789v_cfg edt_panel_cfg = { > + .mode = { DRM_SIMPLE_MODE(240, 320, 43, 58) }, > + .is_ips = false, > + .invert = true, > +}; > + > +/* 5. Jasonic 2.4" (From the 9-bit driver: Custom Height + Offset) */ > +static const struct st7789v_cfg jasonic_panel_cfg = { > + .mode = { DRM_SIMPLE_MODE(240, 280, 37, 43) }, > + .is_ips = true, > + .invert = true, > + .top_offset = 38, > +}; > + > +DEFINE_DRM_GEM_DMA_FOPS(st7789v_fops); > + > +static const struct drm_driver st7789v_driver = { > + .driver_features = DRIVER_GEM | DRIVER_MODESET | DRIVER_ATOMIC, > + .fops = &st7789v_fops, > + DRM_GEM_DMA_DRIVER_OPS_VMAP, > + DRM_FBDEV_DMA_DRIVER_OPS, > + .debugfs_init = mipi_dbi_debugfs_init, > + .name = "st7789v", > + .desc = "Sitronix ST7789V", > + .major = 1, > + .minor = 0, > +}; > + > +static void st7789v_pipe_enable(struct drm_simple_display_pipe *pipe, > + struct drm_crtc_state *crtc_state, > + struct drm_plane_state *plane_state) > +{ > + struct mipi_dbi_dev *dbidev = drm_to_mipi_dbi_dev(pipe->crtc.dev); > + struct st7789v_priv *priv = container_of(dbidev, struct st7789v_priv, > dbidev); > + struct mipi_dbi *dbi = &dbidev->dbi; > + int ret,idx; > + > + if (!drm_dev_enter(pipe->crtc.dev, &idx)) > + return; > + > + ret = mipi_dbi_poweron_reset(dbidev); > + if (ret) > + goto out_exit; > + > + mipi_dbi_command(dbi, MIPI_DCS_SOFT_RESET); > + msleep(150); > + > + mipi_dbi_command(dbi, MIPI_DCS_EXIT_SLEEP_MODE); > + msleep(500); > + > + mipi_dbi_command(dbi, MIPI_DCS_SET_PIXEL_FORMAT, > MIPI_DCS_PIXEL_FMT_16BIT); > + > + if (priv->cfg->is_ips) { > + mipi_dbi_command(dbi, ST7789V_PORCTRL, 0x05, 0x05, 0x00, 0x33, 0x33); > + mipi_dbi_command(dbi, ST7789V_GCTRL, 0x75); > + } else { > + mipi_dbi_command(dbi, ST7789V_PORCTRL, 0x0c, 0x0c, 0x00, 0x33, 0x33); > + mipi_dbi_command(dbi, ST7789V_GCTRL, 0x35); > + } > + > + mipi_dbi_command(dbi, ST7789V_VCOMS, 0x20); > + mipi_dbi_command(dbi, ST7789V_LCMCTRL, 0x2c); > + mipi_dbi_command(dbi, ST7789V_VDVVRHEN, 0x01); > + mipi_dbi_command(dbi, ST7789V_VRHS, 0x12); > + mipi_dbi_command(dbi, ST7789V_VDVS, 0x20); > + mipi_dbi_command(dbi, ST7789V_FRCTRL2, 0x0f); > + mipi_dbi_command(dbi, ST7789V_PWCTRL1, 0xa4, 0xa1); > + > + mipi_dbi_command(dbi, ST7789V_PVGAMCTRL, > + 0xd0, 0x04, 0x0d, 0x11, 0x13, 0x2b, 0x3f, 0x54, > + 0x4c, 0x18, 0x0d, 0x0b, 0x1f, 0x23); > + mipi_dbi_command(dbi, ST7789V_NVGAMCTRL, > + 0xd0, 0x04, 0x0c, 0x11, 0x13, 0x2c, 0x3f, 0x44, > + 0x51, 0x2f, 0x1f, 0x1f, 0x20, 0x23); > + > + if (priv->cfg->invert) > + mipi_dbi_command(dbi, MIPI_DCS_ENTER_INVERT_MODE); > + else > + mipi_dbi_command(dbi, MIPI_DCS_EXIT_INVERT_MODE); > + mipi_dbi_command(dbi, MIPI_DCS_SET_DISPLAY_ON); > + msleep(100); > + > + u8 addr_mode = 0; > + > + switch (dbidev->rotation) { > + case 90: > + > + addr_mode = ST7789V_MADCTL_MV | ST7789V_MADCTL_MY; > + break; > + case 180: > + addr_mode = ST7789V_MADCTL_MX | ST7789V_MADCTL_MY; > + break; > + case 270: > + addr_mode = ST7789V_MADCTL_MV | ST7789V_MADCTL_MX; > + break; > + default: > + addr_mode = 0; > + break; > + } > + > + addr_mode |= ST7789V_MADCTL_BGR; > + > + mipi_dbi_command(dbi, MIPI_DCS_SET_ADDRESS_MODE, addr_mode); > + > + mipi_dbi_enable_flush(dbidev, crtc_state, plane_state); > + > +out_exit: > + drm_dev_exit(idx); > +} > + > +static const struct drm_simple_display_pipe_funcs st7789v_pipe_funcs = > +{ > + DRM_MIPI_DBI_SIMPLE_DISPLAY_PIPE_FUNCS(st7789v_pipe_enable), > +}; > + > +static int st7789v_probe(struct spi_device *spi) > +{ > + struct device *dev = &spi->dev; > + const struct st7789v_cfg *cfg; > + struct mipi_dbi_dev *dbidev; > + struct st7789v_priv *priv; > + struct drm_device *drm; > + struct mipi_dbi *dbi; > + struct gpio_desc *dc; > + u32 rotation = 0; > + int ret; > + > + cfg = device_get_match_data(&spi->dev); > + > + if (!cfg) > + cfg = (void *)spi_get_device_id(spi)->driver_data; > + > + priv = devm_drm_dev_alloc(dev, &st7789v_driver, > + struct st7789v_priv, dbidev.drm); > + > + if (IS_ERR(priv)) > + return PTR_ERR(priv); > + > + dbidev = &priv->dbidev; > + priv->cfg = cfg; > + > + dbi = &dbidev->dbi; > + drm = &dbidev->drm; > + > + spi_set_drvdata(spi, drm); Maybe also add power supply regulator support to make it complete? > + dbi->reset = devm_gpiod_get_optional(dev, "reset", GPIOD_OUT_HIGH); > + if (IS_ERR(dbi->reset)) > + return dev_err_probe(dev, PTR_ERR(dbi->reset), "Failed to get GPIO > 'reset'\n"); The reset logic in mipi_dbi is inverted when compared to panel-st7789v. mipi_dbi needs to be taught the "proper" reset polarity. > + > + dc = devm_gpiod_get(dev, "dc", GPIOD_OUT_LOW); > + if (IS_ERR(dc)) > + return dev_err_probe(dev, PTR_ERR(dc), "Failed to get GPIO 'dc'\n"); This should be optional, since mipi_dbi can handle the "no dc" case. > + > + dbidev->backlight = devm_of_find_backlight(dev); > + if (IS_ERR(dbidev->backlight)) > + return PTR_ERR(dbidev->backlight); > + > + dbidev->left_offset = priv->cfg->left_offset; > + dbidev->top_offset = priv->cfg->top_offset; > + > + device_property_read_u32(dev, "rotation", &rotation); > + > + ret = mipi_dbi_spi_init(spi, dbi, dc); > + if (ret) > + return ret; > + > + ret = mipi_dbi_dev_init(dbidev, &st7789v_pipe_funcs, &cfg->mode, > rotation); > + if (ret) > + return ret; > + > + drm_mode_config_reset(drm); > + > + ret = drm_dev_register(drm, 0); > + if (ret) > + return ret; > + > + drm_client_setup(drm, NULL); > + > + return 0; > +} > + > +static void st7789v_remove(struct spi_device *spi) > +{ > + struct drm_device *drm = spi_get_drvdata(spi); > + drm_dev_unplug(drm); > + drm_atomic_helper_shutdown(drm); > +} > + > +static void st7789v_shutdown(struct spi_device *spi) > +{ > + drm_atomic_helper_shutdown(spi_get_drvdata(spi)); > +} > + > + > +static const struct of_device_id st7789v_of_match[] = { > + { .compatible = "sitronix,st7789v", .data = &generic_cfg }, > + { .compatible = "hannstar,hsd20-ips", .data = &hsd20_ips_cfg }, > + { .compatible = "inanbo,t28cp45tn89-v17", .data = &inanbo_panel_cfg }, > + { .compatible = "edt,et028013dma", .data = &edt_panel_cfg }, > + { .compatible = "jasonic,jt240mhqs-hwt-ek-e3", .data = > &jasonic_panel_cfg }, > + { } > +}; > +MODULE_DEVICE_TABLE(of, st7789v_of_match); We typically don't want two drivers matching on the same devices. The driver match and probe order becomes hard to predict. Instead this functionality could be merged into the existing panel-st7789v driver. You mentioned above that that driver only supports the 9-bit SPI transfer mode. However porting that driver over to mipi_dbi would fix this, and remove some redundant code. And tinydrm support could be added on top of that. I actually mentioned I was going to work on this on IRC. But I only ported the driver over to use mipi_dbi, and haven't gotten around to adding tinydrm support. I can send out the conversion patches if that helps you. > + > +static const struct spi_device_id st7789v_id[] = { > + { "st7789v", 0 }, You should add all the other ones as well. OF-based SPI driver module loading doesn't seem to work. I think that's a known issue? > + { }, > +}; > +MODULE_DEVICE_TABLE(spi, st7789v_id); > + > +static struct spi_driver st7789v_spi_driver = { > + .driver = { > + .name = "st7789v", And you definitely can't have two drivers with the same name. > + .of_match_table = st7789v_of_match, > + }, > + .probe = st7789v_probe, > + .remove = st7789v_remove, > + .shutdown = st7789v_shutdown, > + .id_table = st7789v_id, > +}; > + Empty line not needed here. > +module_spi_driver(st7789v_spi_driver); > + > +MODULE_DESCRIPTION("Sitronix ST7789V DRM driver"); > +MODULE_AUTHOR("Archit Anant <[email protected]>"); > +MODULE_LICENSE("GPL"); > \ No newline at end of file ^ ChenYu
