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
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.
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
Signed-off-by: Archit Anant <architanant5@gmail.com>
---
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
+
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 <architanant5@gmail.com>
+ */
+
+#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>
+
+#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>
+#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);
+
+ 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");
+
+ 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");
+
+ 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);
+
+static const struct spi_device_id st7789v_id[] = {
+ { "st7789v", 0 },
+ { },
+};
+MODULE_DEVICE_TABLE(spi, st7789v_id);
+
+static struct spi_driver st7789v_spi_driver = {
+ .driver = {
+ .name = "st7789v",
+ .of_match_table = st7789v_of_match,
+ },
+ .probe = st7789v_probe,
+ .remove = st7789v_remove,
+ .shutdown = st7789v_shutdown,
+ .id_table = st7789v_id,
+};
+
+module_spi_driver(st7789v_spi_driver);
+
+MODULE_DESCRIPTION("Sitronix ST7789V DRM driver");
+MODULE_AUTHOR("Archit Anant <architanant5@gmail.com>");
+MODULE_LICENSE("GPL");
\ No newline at end of file
--
2.39.5On 2/14/26 1:01 AM, Archit Anant 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. > > 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 > Do we actually need a custom driver for these or can we use drivers/gpu/drm/tiny/panel-mipi-dbi.c with a firmware file for init?
Hi David, > Do we actually need a custom driver for these or can we use > drivers/gpu/drm/tiny/panel-mipi-dbi.c with a firmware file for > init? That was my initial thought as well, but looking at the staging driver (fb_st7789v.c), there is conditional logic in the initialization sequence. The HSD20_IPS panel requires different PORCTRL (0xB2), GCTRL (0xB7), and Gamma (0xE0/E1) settings compared to the standard panel. A static firmware blob via panel-mipi-dbi would not allow selecting between these configurations based on the compatible string, so a dedicated driver seemed necessary to preserve this support. Best regards, Archit
On 2/14/26 11:21 PM, Archit Anant wrote: > Hi David, > >> Do we actually need a custom driver for these or can we use >> drivers/gpu/drm/tiny/panel-mipi-dbi.c with a firmware file for >> init? > > That was my initial thought as well, but looking at the staging driver > (fb_st7789v.c), there is conditional logic in the initialization sequence. > > The HSD20_IPS panel requires different PORCTRL (0xB2), GCTRL (0xB7), and > Gamma (0xE0/E1) settings compared to the standard panel. A static > firmware blob via panel-mipi-dbi would not allow selecting between > these configurations based on the compatible string, so a dedicated > driver seemed necessary to preserve this support. > > Best regards, > Archit If two different panels are not 100% compatible with each other, they should not have the same compatible string. It seems like it would be much more efficient to fix the existing devicetree/driver if needed rather than writing an entire new driver.
On Mon, Feb 16, 2026 at 4:15 AM David Lechner <david@lechnology.com> wrote: Hi David, > > On 2/14/26 11:21 PM, Archit Anant wrote: > > Hi David, > > > >> Do we actually need a custom driver for these or can we use > >> drivers/gpu/drm/tiny/panel-mipi-dbi.c with a firmware file for > >> init? > > > > That was my initial thought as well, but looking at the staging driver > > (fb_st7789v.c), there is conditional logic in the initialization sequence. > > > > The HSD20_IPS panel requires different PORCTRL (0xB2), GCTRL (0xB7), and > > Gamma (0xE0/E1) settings compared to the standard panel. A static > > firmware blob via panel-mipi-dbi would not allow selecting between > > these configurations based on the compatible string, so a dedicated > > driver seemed necessary to preserve this support. > > > > Best regards, > > Archit > > If two different panels are not 100% compatible with each other, they > should not have the same compatible string. > > It seems like it would be much more efficient to fix the existing > devicetree/driver if needed rather than writing an entire new driver. Agreed. ChenYu Tsai mentioned he is working on refactoring the existing panel-sitronix-st7789v driver to use mipi_dbi. Once that is ready, I can add the HSD20-IPS panel support to that driver using a distinct compatible string and associated configuration data, rather than forking a new driver. I will drop this standalone driver patch and wait for Chen-Yu's series. -- Sincerely, Archit Anant
On Sat, Feb 14, 2026 at 5:21 PM Archit Anant <architanant5@gmail.com> 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 <architanant5@gmail.com>
> ---
> 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 <architanant5@gmail.com>
> + */
> +
> +#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 <architanant5@gmail.com>");
> +MODULE_LICENSE("GPL");
> \ No newline at end of file
^
ChenYu
Hi ChenYu,
Thank you for the detailed review and the pointers toward the documentation.
I will ensure the headers are sorted alphabetically and the driver name
conflict is resolved in the next iteration.
> The reset logic in mipi_dbi is inverted when compared to panel-st7789v.
> mipi_dbi needs to be taught the "proper" reset polarity.
Noted. I will look into the mipi_dbi core to see how to handle the reset
polarity correctly.
> 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.
That would be fantastic and would save a lot of redundant effort. If you
send out the patches to convert the existing panel-st7789v driver to
mipi_dbi, I would be happy to build the 'tiny' (simple display pipe)
support on top of your series.
Please CC me when you post them, and I will rebase my work accordingly.
Best regards,
Archit
On Sat, Feb 14, 2026 at 6:35 PM Chen-Yu Tsai <wens@kernel.org> wrote:
>
> On Sat, Feb 14, 2026 at 5:21 PM Archit Anant <architanant5@gmail.com> 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 <architanant5@gmail.com>
> > ---
> > 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 <architanant5@gmail.com>
> > + */
> > +
> > +#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 <architanant5@gmail.com>");
> > +MODULE_LICENSE("GPL");
> > \ No newline at end of file
>
> ^
>
>
> ChenYu
--
Sincerely,
Archit Anant
Archit Anant <architanant5@gmail.com> writes:
Hello Archit,
> Hi ChenYu,
>
> Thank you for the detailed review and the pointers toward the documentation.
> I will ensure the headers are sorted alphabetically and the driver name
> conflict is resolved in the next iteration.
>
>> The reset logic in mipi_dbi is inverted when compared to panel-st7789v.
>> mipi_dbi needs to be taught the "proper" reset polarity.
>
> Noted. I will look into the mipi_dbi core to see how to handle the reset
> polarity correctly.
>
>> 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.
>
> That would be fantastic and would save a lot of redundant effort. If you
> send out the patches to convert the existing panel-st7789v driver to
> mipi_dbi, I would be happy to build the 'tiny' (simple display pipe)
> support on top of your series.
>
I think we want to get rid of the simple display pipeline and instead just
use regulator atomic helpers, even for the tiny DRM drivers.
Please take a look to previous commits such as 2037174993c8 ("drm/bochs:
Use regular atomic helpers") or 622113b9f11f ("drm/ssd130x: Replace simple
display helpers with the atomic helpers").
--
Best regards,
Javier Martinez Canillas
Core Platforms
Red Hat
On Mon, Feb 16, 2026 at 1:17 PM Javier Martinez Canillas
<javierm@redhat.com> wrote:
Hi Javier,
>
> Archit Anant <architanant5@gmail.com> writes:
>
> Hello Archit,
>
> > Hi ChenYu,
> >
> > Thank you for the detailed review and the pointers toward the documentation.
> > I will ensure the headers are sorted alphabetically and the driver name
> > conflict is resolved in the next iteration.
> >
> >> The reset logic in mipi_dbi is inverted when compared to panel-st7789v.
> >> mipi_dbi needs to be taught the "proper" reset polarity.
> >
> > Noted. I will look into the mipi_dbi core to see how to handle the reset
> > polarity correctly.
> >
> >> 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.
> >
> > That would be fantastic and would save a lot of redundant effort. If you
> > send out the patches to convert the existing panel-st7789v driver to
> > mipi_dbi, I would be happy to build the 'tiny' (simple display pipe)
> > support on top of your series.
> >
>
> I think we want to get rid of the simple display pipeline and instead just
> use regulator atomic helpers, even for the tiny DRM drivers.
>
> Please take a look to previous commits such as 2037174993c8 ("drm/bochs:
> Use regular atomic helpers") or 622113b9f11f ("drm/ssd130x: Replace simple
> display helpers with the atomic helpers").
>
> --
> Best regards,
>
> Javier Martinez Canillas
> Core Platforms
> Red Hat
>
Thank you for pointing this out. I based this implementation on the
existing st7735r driver, which currently uses the simple pipe.
I will study the bochs and ssd130x commits to understand the migration to
regular atomic helpers.
If the goal is to move tiny DRM drivers away from the simple pipe, updating
the Sitronix drivers to this new pattern sounds much better.
I will incorporate this into my plan for the next iteration
(building on top of ChenYu's work).
--
Sincerely,
Archit Anant
Hi
Am 16.02.26 um 16:38 schrieb Archit Anant:
> On Mon, Feb 16, 2026 at 1:17 PM Javier Martinez Canillas
> <javierm@redhat.com> wrote:
>
> Hi Javier,
>
>> Archit Anant <architanant5@gmail.com> writes:
>>
>> Hello Archit,
>>
>>> Hi ChenYu,
>>>
>>> Thank you for the detailed review and the pointers toward the documentation.
>>> I will ensure the headers are sorted alphabetically and the driver name
>>> conflict is resolved in the next iteration.
>>>
>>>> The reset logic in mipi_dbi is inverted when compared to panel-st7789v.
>>>> mipi_dbi needs to be taught the "proper" reset polarity.
>>> Noted. I will look into the mipi_dbi core to see how to handle the reset
>>> polarity correctly.
>>>
>>>> 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.
>>> That would be fantastic and would save a lot of redundant effort. If you
>>> send out the patches to convert the existing panel-st7789v driver to
>>> mipi_dbi, I would be happy to build the 'tiny' (simple display pipe)
>>> support on top of your series.
>>>
>> I think we want to get rid of the simple display pipeline and instead just
>> use regulator atomic helpers, even for the tiny DRM drivers.
>>
>> Please take a look to previous commits such as 2037174993c8 ("drm/bochs:
>> Use regular atomic helpers") or 622113b9f11f ("drm/ssd130x: Replace simple
>> display helpers with the atomic helpers").
>>
>> --
>> Best regards,
>>
>> Javier Martinez Canillas
>> Core Platforms
>> Red Hat
>>
> Thank you for pointing this out. I based this implementation on the
> existing st7735r driver, which currently uses the simple pipe.
>
> I will study the bochs and ssd130x commits to understand the migration to
> regular atomic helpers.
>
> If the goal is to move tiny DRM drivers away from the simple pipe, updating
> the Sitronix drivers to this new pattern sounds much better.
> I will incorporate this into my plan for the next iteration
> (building on top of ChenYu's work).
The thing is that this driver builds upon mipi_dbi_dev, which uses
simple_display_pipeline internally. So it might be legitimate to use it
here. Otherwise all the MIPI support from drm_mipi_dbi.c would have to
be duplicated.
Best regards
Thomas
>
--
--
Thomas Zimmermann
Graphics Driver Developer
SUSE Software Solutions Germany GmbH
Frankenstr. 146, 90461 Nürnberg, Germany, www.suse.com
GF: Jochen Jaser, Andrew McDonald, Werner Knoblich, (HRB 36809, AG Nürnberg)
Hi Thomas, On Thu, Feb 19, 2026 at 3:41 PM Thomas Zimmermann <tzimmermann@suse.de> wrote: > > Hi > > The thing is that this driver builds upon mipi_dbi_dev, which uses > simple_display_pipeline internally. So it might be legitimate to use it > here. Otherwise all the MIPI support from drm_mipi_dbi.c would have to > be duplicated. > > Best regards > Thomas Thank you for the clarification. Since mipi_dbi relies on the simple display pipeline, I will stick to using mipi_dbi structures for this series. I will proceed with rebasing my work on top of ChenYu's series (which also uses mipi_dbi) to add the standalone driver support. -- Sincerely, Archit Anant
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