[RFC PATCH] drm/sitronix: add ST7789V panel driver
From: Archit Anant
Date: Sat Feb 14 2026 - 02:01:46 EST
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@xxxxxxxxx>
---
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@xxxxxxxxx>
+ */
+
+#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@xxxxxxxxx>");
+MODULE_LICENSE("GPL");
\ No newline at end of file
--
2.39.5