[PATCH v2 19/21] drm/panel: add driver for Waveshare 8.8" DSI TOUCH-A panel

Dmitry Baryshkov
2026-04-11T12:11:34Z

Add driver for the panel found on Waveshare 8.8" DSI TOUCH-A kit. It
uses ota7290b IC as a controller.

Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
drivers/gpu/drm/panel/Kconfig | 12 ++
drivers/gpu/drm/panel/Makefile | 1 +
drivers/gpu/drm/panel/panel-focaltech-ota7290b.c | 208 +++++++++++++++++++++++
3 files changed, 221 insertions(+)

diff --git a/drivers/gpu/drm/panel/Kconfig b/drivers/gpu/drm/panel/Kconfig
index ba527b4d7737..979109c27b9b 100644
--- a/drivers/gpu/drm/panel/Kconfig
+++ b/drivers/gpu/drm/panel/Kconfig
@@ -144,6 +144,18 @@ config DRM_PANEL_FEIYANG_FY07024DI26A30D
Say Y if you want to enable support for panels based on the
Feiyang FY07024DI26A30-D MIPI-DSI interface.

+config DRM_PANEL_FOCALTECH_OTA7290B
+ tristate "Focaltech OTA7290B"
+ depends on DRM_MIPI_DSI
+ depends on I2C
+ depends on BACKLIGHT_CLASS_DEVICE
+ select DRM_KMS_HELPER
+ help
+ Enable support for panels using OTA7290B as a controller (for
+ example, Waveshare 12.3" DSI TOUCH-A panel). Say Y here if you want
+ to enable support for this panel. To compile this driver as a module,
+ choose M here.
+
config DRM_PANEL_DSI_CM
tristate "Generic DSI command mode panels"
depends on OF
diff --git a/drivers/gpu/drm/panel/Makefile b/drivers/gpu/drm/panel/Makefile
index a4291dc3905b..0d694acbfbb6 100644
--- a/drivers/gpu/drm/panel/Makefile
+++ b/drivers/gpu/drm/panel/Makefile
@@ -17,6 +17,7 @@ obj-$(CONFIG_DRM_PANEL_EBBG_FT8719) += panel-ebbg-ft8719.o
obj-$(CONFIG_DRM_PANEL_ELIDA_KD35T133) += panel-elida-kd35t133.o
obj-$(CONFIG_DRM_PANEL_FEIXIN_K101_IM2BA02) += panel-feixin-k101-im2ba02.o
obj-$(CONFIG_DRM_PANEL_FEIYANG_FY07024DI26A30D) += panel-feiyang-fy07024di26a30d.o
+obj-$(CONFIG_DRM_PANEL_FOCALTECH_OTA7290B) += panel-focaltech-ota7290b.o
obj-$(CONFIG_DRM_PANEL_HIMAX_HX8279) += panel-himax-hx8279.o
obj-$(CONFIG_DRM_PANEL_HIMAX_HX83102) += panel-himax-hx83102.o
obj-$(CONFIG_DRM_PANEL_HIMAX_HX83112A) += panel-himax-hx83112a.o
diff --git a/drivers/gpu/drm/panel/panel-focaltech-ota7290b.c b/drivers/gpu/drm/panel/panel-focaltech-ota7290b.c
new file mode 100644
index 000000000000..991d6a4caf17
--- /dev/null
+++ b/drivers/gpu/drm/panel/panel-focaltech-ota7290b.c
@@ -0,0 +1,208 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2024 Waveshare International Limited
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
+ */
+
+#include <linux/delay.h>
+#include <linux/device.h>
+#include <linux/err.h>
+#include <linux/errno.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/of.h>
+
+#include <linux/gpio/consumer.h>
+#include <linux/regulator/consumer.h>
+
+#include <drm/drm_mipi_dsi.h>
+#include <drm/drm_modes.h>
+#include <drm/drm_panel.h>
+#include <drm/drm_probe_helper.h>
+
+struct ota7290b {
+ struct drm_panel panel;
+ struct mipi_dsi_device *dsi;
+
+ struct regulator *power;
+ struct gpio_desc *reset;
+ struct regulator *avdd;
+ struct regulator *iovcc;
+
+ enum drm_panel_orientation orientation;
+};
+
+static inline struct ota7290b *panel_to_ota(struct drm_panel *panel)
+{
+ return container_of(panel, struct ota7290b, panel);
+}
+
+static int ota7290b_prepare(struct drm_panel *panel)
+{
+ struct ota7290b *ctx = panel_to_ota(panel);
+ struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
+ int ret;
+
+ if (ctx->iovcc) {
+ ret = regulator_enable(ctx->iovcc);
+ if (ret)
+ dev_err(panel->dev, "failed to enable IO regulator: %d\n", ret);
+ }
+
+ if (ctx->avdd) {
+ ret = regulator_enable(ctx->avdd);
+ if (ret)
+ dev_err(panel->dev, "failed to enable AVDD regulator: %d\n", ret);
+ }
+
+ if (ctx->reset) {
+ gpiod_set_value_cansleep(ctx->reset, 0);
+ msleep(60);
+ gpiod_set_value_cansleep(ctx->reset, 1);
+ msleep(60);
+ gpiod_set_value_cansleep(ctx->reset, 0);
+ msleep(60);
+ }
+
+ mipi_dsi_dcs_exit_sleep_mode_multi(&dsi_ctx);
+ mipi_dsi_msleep(&dsi_ctx, 120);
+ mipi_dsi_dcs_set_display_on_multi(&dsi_ctx);
+ mipi_dsi_msleep(&dsi_ctx, 50);
+
+ if (dsi_ctx.accum_err < 0)
+ dev_err(panel->dev, "failed to init panel: %d\n", ret);
+
+ return dsi_ctx.accum_err;
+}
+
+static int ota7290b_unprepare(struct drm_panel *panel)
+{
+ struct ota7290b *ctx = panel_to_ota(panel);
+ struct mipi_dsi_multi_context dsi_ctx = { .dsi = ctx->dsi };
+
+ mipi_dsi_dcs_set_display_off_multi(&dsi_ctx);
+ mipi_dsi_dcs_enter_sleep_mode_multi(&dsi_ctx);
+
+ if (ctx->reset) {
+ gpiod_set_value_cansleep(ctx->reset, 1);
+ msleep(5);
+ }
+
+ if (ctx->avdd)
+ regulator_disable(ctx->avdd);
+
+ if (ctx->iovcc)
+ regulator_disable(ctx->iovcc);
+
+ return 0;
+}
+
+static const struct drm_display_mode waveshare_dsi_touch_8_8_a_mode = {
+ .clock = 75000,
+
+ .hdisplay = 480,
+ .hsync_start = 480 + 50,
+ .hsync_end = 480 + 50 + 50,
+ .htotal = 480 + 50 + 50 + 50,
+
+ .vdisplay = 1920,
+ .vsync_start = 1920 + 20,
+ .vsync_end = 1920 + 20 + 20,
+ .vtotal = 1920 + 20 + 20 + 20,
+
+ .width_mm = 68,
+ .height_mm = 219,
+ .type = DRM_MODE_TYPE_DRIVER,
+};
+
+static int ota7290b_get_modes(struct drm_panel *panel,
+ struct drm_connector *connector)
+{
+ return drm_connector_helper_get_modes_fixed(connector, &waveshare_dsi_touch_8_8_a_mode);
+}
+
+static enum drm_panel_orientation ota7290b_get_orientation(struct drm_panel *panel)
+{
+ struct ota7290b *ctx = panel_to_ota(panel);
+
+ return ctx->orientation;
+}
+
+static const struct drm_panel_funcs ota7290b_funcs = {
+ .prepare = ota7290b_prepare,
+ .unprepare = ota7290b_unprepare,
+ .get_modes = ota7290b_get_modes,
+ .get_orientation = ota7290b_get_orientation,
+};
+
+static int ota7290b_probe(struct mipi_dsi_device *dsi)
+{
+ struct ota7290b *ctx;
+ int ret;
+
+ ctx = devm_drm_panel_alloc(&dsi->dev, struct ota7290b, panel,
+ &ota7290b_funcs,
+ DRM_MODE_CONNECTOR_DSI);
+ if (!ctx)
+ return -ENOMEM;
+ mipi_dsi_set_drvdata(dsi, ctx);
+ ctx->dsi = dsi;
+
+ ctx->reset = devm_gpiod_get_optional(&dsi->dev, "reset", GPIOD_OUT_HIGH);
+ if (IS_ERR(ctx->reset))
+ return dev_err_probe(&dsi->dev, PTR_ERR(ctx->reset),
+ "Couldn't get our reset GPIO\n");
+
+ ctx->iovcc = devm_regulator_get_optional(&dsi->dev, "iovcc");
+ if (IS_ERR(ctx->iovcc))
+ return dev_err_probe(&dsi->dev, PTR_ERR(ctx->iovcc),
+ "Couldn't get our iovcc supply\n");
+
+ ctx->avdd = devm_regulator_get_optional(&dsi->dev, "avdd");
+ if (IS_ERR(ctx->avdd))
+ return dev_err_probe(&dsi->dev, PTR_ERR(ctx->avdd),
+ "Couldn't get our avdd supply\n");
+
+ ret = of_drm_get_panel_orientation(
+ dsi->dev.of_node, &ctx->orientation);
+ if (ret) {
+ dev_err(&dsi->dev, "%pOF: failed to get orientation: %d\n",
+ dsi->dev.of_node, ret);
+ return ret;
+ }
+
+ ret = drm_panel_of_backlight(&ctx->panel);
+ if (ret)
+ return ret;
+
+ ctx->panel.prepare_prev_first = true;
+
+ ret = devm_drm_panel_add(&dsi->dev, &ctx->panel);
+ if (ret)
+ return ret;
+
+ dsi->mode_flags = MIPI_DSI_MODE_VIDEO | MIPI_DSI_MODE_VIDEO_HSE |
+ MIPI_DSI_MODE_LPM | MIPI_DSI_CLOCK_NON_CONTINUOUS,
+ dsi->format = MIPI_DSI_FMT_RGB888,
+ dsi->lanes = 2;
+
+ return devm_mipi_dsi_attach(&dsi->dev, dsi);
+}
+
+static const struct of_device_id ota7290b_of_match[] = {
+ { .compatible = "waveshare,8.8-dsi-touch-a", },
+ {}
+};
+MODULE_DEVICE_TABLE(of, ota7290b_of_match);
+
+static struct mipi_dsi_driver ota7290b_driver = {
+ .probe = ota7290b_probe,
+ .driver = {
+ .name = "focaltech-ota7290b",
+ .of_match_table = ota7290b_of_match,
+ },
+};
+module_mipi_dsi_driver(ota7290b_driver);
+
+MODULE_DESCRIPTION("Panel driver for Focaltech OTA7290B panels");
+MODULE_LICENSE("GPL");

--
2.47.3