[PATCH v5 0/2] drm/panel: support Waveshare DSI TOUCH kits

[PATCH v5 0/2] drm/panel: support Waveshare DSI TOUCH kits

[Dmitry Baryshkov]

The Waveshare DSI TOUCH family of DSI panel kits feature different DSI
video-mode panels, bundled with the separate controlling circuit,
produing necessary voltages from the 3.3V and 5V supplies. Extend panel
drivers to support those Waveshare panels and also add GPIO driver for
the onboard control circuitry.

Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
Changes in v5:
- Dropped applied patches, leaving just GPIO part.
- Dropped panel example from the GPIO controller node, it's has no added
  value.
- Link to v4: https://patch.msgid.link/20260418-waveshare-dsi-touch-v4-0-b249f3e702bd@oss.qualcomm.com

Changes in v4:
- Dropped patches applied to drm-misc-next
- Link to v3: https://patch.msgid.link/20260413-waveshare-dsi-touch-v3-0-3aeb53022c32@oss.qualcomm.com

Changes in v3:
- Fix another typo in the focaltech,ota7290b schema, sorted out voltage
  supplies in the schema and in the driver
- Dropped Ricardo's T-B from bindings patch (Krzysztof)
- In the Waveshare GPIO driver bumped max register to REG_VERSION (Jie
  Gan)
- Add a lanes vs config check in the JD9365 driver (Jie Gan)
- Link to v2: https://patch.msgid.link/20260411-waveshare-dsi-touch-v2-0-75cdbeac5156@oss.qualcomm.com

Changes in v2:
- Fixed errors in focaltech,ota7290b and waveshare,dsi-touch-gpio schemas
- Split the JD9365 patch, making the changes more obvious (and
  describing panel classes)
- Cleaned up GPIO driver: moved NUM_GPIOS from the enum, switched to
  guard(), added regmap error handling, dropped
waveshare_gpio_i2c_read() (Bartosz)
- Link to v1: https://patch.msgid.link/20260401-waveshare-dsi-touch-v1-0-5e9119b5a014@oss.qualcomm.com

---
Dmitry Baryshkov (2):
      dt-bindings: gpio: describe Waveshare GPIO controller
      gpio: add GPIO controller found on Waveshare DSI TOUCH panels

 .../bindings/gpio/waveshare,dsi-touch-gpio.yaml    |  73 ++++++++
 drivers/gpio/Kconfig                               |  10 +
 drivers/gpio/Makefile                              |   1 +
 drivers/gpio/gpio-waveshare-dsi.c                  | 208 +++++++++++++++++++++
 4 files changed, 292 insertions(+)
---
base-commit: 735d2f48cadaa9a87e7c7601667878de70c771c5
change-id: 20260401-waveshare-dsi-touch-e1717a1ffc40

Best regards,
--  
With best wishes
Dmitry

[PATCH v5 1/2] dt-bindings: gpio: describe Waveshare GPIO controller

[Dmitry Baryshkov]

The Waveshare DSI TOUCH family of panels has separate on-board GPIO
controller, which controls power supplies to the panel and the touch
screen and provides reset pins for both the panel and the touchscreen.
Also it provides a simple PWM controller for panel backlight.

Add bindings for these GPIO controllers. As overall integration might be
not very obvious (and it differs significantly from the bindings used by
the original drivers), provide complete example with the on-board
regulators and the DSI panel.

Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 .../bindings/gpio/waveshare,dsi-touch-gpio.yaml    | 73 ++++++++++++++++++++++
 1 file changed, 73 insertions(+)

diff --git a/Documentation/devicetree/bindings/gpio/waveshare,dsi-touch-gpio.yaml b/Documentation/devicetree/bindings/gpio/waveshare,dsi-touch-gpio.yaml
new file mode 100644
index 000000000000..091e1fffcd47
--- /dev/null
+++ b/Documentation/devicetree/bindings/gpio/waveshare,dsi-touch-gpio.yaml
@@ -0,0 +1,73 @@
+# SPDX-License-Identifier: (GPL-2.0 OR BSD-2-Clause)
+%YAML 1.2
+---
+$id: http://devicetree.org/schemas/gpio/waveshare,dsi-touch-gpio.yaml#
+$schema: http://devicetree.org/meta-schemas/core.yaml#
+
+title: Waveshare GPIO controller on DSI TOUCH panels
+
+maintainers:
+  - Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
+
+description:
+  Waveshare DSI TOUCH panel kits contain separate GPIO controller for toggling
+  power supplies and panel / touchscreen resets.
+
+properties:
+  compatible:
+    const: waveshare,dsi-touch-gpio
+
+  reg:
+    maxItems: 1
+
+  gpio-controller: true
+
+  '#gpio-cells':
+    const: 2
+
+required:
+  - compatible
+  - reg
+  - gpio-controller
+  - "#gpio-cells"
+
+additionalProperties: false
+
+examples:
+  - |
+    #include <dt-bindings/gpio/gpio.h>
+
+    i2c {
+        #address-cells = <1>;
+        #size-cells = <0>;
+
+        wsgpio: gpio@45 {
+            compatible = "waveshare,dsi-touch-gpio";
+            reg = <0x45>;
+            gpio-controller;
+            #gpio-cells = <2>;
+        };
+    };
+
+    panel_avdd: regulator-panel-avdd {
+        compatible = "regulator-fixed";
+        regulator-name = "panel-avdd";
+        gpios = <&wsgpio 0 GPIO_ACTIVE_HIGH>;
+        enable-active-high;
+    };
+
+    panel_iovcc: regulator-panel-iovcc {
+        compatible = "regulator-fixed";
+        regulator-name = "panel-iovcc";
+        gpios = <&wsgpio 4 GPIO_ACTIVE_HIGH>;
+        enable-active-high;
+    };
+
+    panel_vcc: regulator-panel-vcc {
+        compatible = "regulator-fixed";
+        regulator-name = "panel-vcc";
+        gpios = <&wsgpio 8 GPIO_ACTIVE_HIGH>;
+        enable-active-high;
+        regulator-always-on;
+    };
+...

-- 
2.47.3

[PATCH v5 2/2] gpio: add GPIO controller found on Waveshare DSI TOUCH panels

[Dmitry Baryshkov]

The Waveshare DSI TOUCH family of panels has separate on-board GPIO
controller, which controls power supplies to the panel and the touch
screen and provides reset pins for both the panel and the touchscreen.
Also it provides a simple PWM controller for panel backlight. Add
support for this GPIO controller.

Tested-by: Riccardo Mereu <r.mereu@arduino.cc>
Reviewed-by: Linus Walleij <linusw@kernel.org>
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
---
 drivers/gpio/Kconfig              |  10 ++
 drivers/gpio/Makefile             |   1 +
 drivers/gpio/gpio-waveshare-dsi.c | 208 ++++++++++++++++++++++++++++++++++++++
 3 files changed, 219 insertions(+)

diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig
index ce95a25298a8..8ae6a423da6d 100644
--- a/drivers/gpio/Kconfig
+++ b/drivers/gpio/Kconfig
@@ -806,6 +806,16 @@ config GPIO_VISCONTI
 	help
 	  Say yes here to support GPIO on Tohisba Visconti.
 
+config GPIO_WAVESHARE_DSI_TOUCH
+	tristate "Waveshare GPIO controller for DSI panels"
+	depends on BACKLIGHT_CLASS_DEVICE
+	depends on I2C
+	select REGMAP_I2C
+	help
+	  Enable support for the GPIO and PWM controller found on Waveshare DSI
+	  TOUCH panel kits. It provides GPIOs (used for regulator control and
+          resets) and backlight support.
+
 config GPIO_WCD934X
 	tristate "Qualcomm WCD9340/WCD9341 GPIO controller driver"
 	depends on MFD_WCD934X
diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile
index b267598b517d..2ea47d9d3dca 100644
--- a/drivers/gpio/Makefile
+++ b/drivers/gpio/Makefile
@@ -205,6 +205,7 @@ obj-$(CONFIG_GPIO_VIRTUSER)		+= gpio-virtuser.o
 obj-$(CONFIG_GPIO_VIRTIO)		+= gpio-virtio.o
 obj-$(CONFIG_GPIO_VISCONTI)		+= gpio-visconti.o
 obj-$(CONFIG_GPIO_VX855)		+= gpio-vx855.o
+obj-$(CONFIG_GPIO_WAVESHARE_DSI_TOUCH)	+= gpio-waveshare-dsi.o
 obj-$(CONFIG_GPIO_WCD934X)		+= gpio-wcd934x.o
 obj-$(CONFIG_GPIO_WHISKEY_COVE)		+= gpio-wcove.o
 obj-$(CONFIG_GPIO_WINBOND)		+= gpio-winbond.o
diff --git a/drivers/gpio/gpio-waveshare-dsi.c b/drivers/gpio/gpio-waveshare-dsi.c
new file mode 100644
index 000000000000..38f52351bb58
--- /dev/null
+++ b/drivers/gpio/gpio-waveshare-dsi.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/backlight.h>
+#include <linux/err.h>
+#include <linux/fb.h>
+#include <linux/gpio/driver.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/regmap.h>
+
+/* I2C registers of the microcontroller. */
+#define REG_TP		0x94
+#define REG_LCD		0x95
+#define REG_PWM		0x96
+#define REG_SIZE	0x97
+#define REG_ID		0x98
+#define REG_VERSION	0x99
+
+enum {
+	GPIO_AVDD = 0,
+	GPIO_PANEL_RESET = 1,
+	GPIO_BL_ENABLE = 2,
+	GPIO_IOVCC = 4,
+	GPIO_VCC = 8,
+	GPIO_TS_RESET = 9,
+};
+
+#define NUM_GPIO 16
+
+struct waveshare_gpio {
+	struct mutex dir_lock;
+	struct mutex pwr_lock;
+	struct regmap *regmap;
+	u16 poweron_state;
+
+	struct gpio_chip gc;
+};
+
+static const struct regmap_config waveshare_gpio_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = REG_VERSION,
+};
+
+static int waveshare_gpio_get(struct waveshare_gpio *state, unsigned int offset)
+{
+	u16 pwr_state;
+
+	guard(mutex)(&state->pwr_lock);
+	pwr_state = state->poweron_state & BIT(offset);
+
+	return !!pwr_state;
+}
+
+static int waveshare_gpio_set(struct waveshare_gpio *state, unsigned int offset, int value)
+{
+	u16 last_val;
+	int err;
+
+	guard(mutex)(&state->pwr_lock);
+
+	last_val = state->poweron_state;
+	if (value)
+		last_val |= BIT(offset);
+	else
+		last_val &= ~BIT(offset);
+
+	state->poweron_state = last_val;
+
+	err = regmap_write(state->regmap, REG_TP, last_val >> 8);
+	if (!err)
+		err = regmap_write(state->regmap, REG_LCD, last_val & 0xff);
+
+	return err;
+}
+
+static int waveshare_gpio_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
+{
+	return GPIO_LINE_DIRECTION_OUT;
+}
+
+static int waveshare_gpio_gpio_get(struct gpio_chip *gc, unsigned int offset)
+{
+	struct waveshare_gpio *state = gpiochip_get_data(gc);
+
+	return waveshare_gpio_get(state, offset);
+}
+
+static int waveshare_gpio_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
+{
+	struct waveshare_gpio *state = gpiochip_get_data(gc);
+
+	return waveshare_gpio_set(state, offset, value);
+}
+
+static int waveshare_gpio_update_status(struct backlight_device *bl)
+{
+	struct waveshare_gpio *state = bl_get_data(bl);
+	int brightness = backlight_get_brightness(bl);
+
+	waveshare_gpio_set(state, GPIO_BL_ENABLE, brightness);
+
+	return regmap_write(state->regmap, REG_PWM, brightness);
+}
+
+static const struct backlight_ops waveshare_gpio_bl = {
+	.update_status = waveshare_gpio_update_status,
+};
+
+static int waveshare_gpio_probe(struct i2c_client *i2c)
+{
+	struct backlight_properties props = {};
+	struct waveshare_gpio *state;
+	struct device *dev = &i2c->dev;
+	struct backlight_device *bl;
+	struct regmap *regmap;
+	unsigned int data;
+	int ret;
+
+	state = devm_kzalloc(dev, sizeof(*state), GFP_KERNEL);
+	if (!state)
+		return -ENOMEM;
+
+	ret = devm_mutex_init(dev, &state->dir_lock);
+	if (ret)
+		return ret;
+
+	ret = devm_mutex_init(dev, &state->pwr_lock);
+	if (ret)
+		return ret;
+
+	regmap = devm_regmap_init_i2c(i2c, &waveshare_gpio_regmap_config);
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap), "Failed to allocate register map\n");
+
+	state->regmap = regmap;
+	i2c_set_clientdata(i2c, state);
+
+	ret = regmap_read(regmap, REG_ID, &data);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to read register\n");
+
+	dev_dbg(dev, "waveshare panel hw id = 0x%x\n", data);
+
+	ret = regmap_read(regmap, REG_SIZE, &data);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to read register\n");
+
+	dev_dbg(dev, "waveshare panel size = %d\n", data);
+
+	ret = regmap_read(regmap, REG_VERSION, &data);
+	if (ret < 0)
+		return dev_err_probe(dev, ret, "Failed to read register\n");
+
+	dev_dbg(dev, "waveshare panel mcu version = 0x%x\n", data);
+
+	ret = waveshare_gpio_set(state, GPIO_TS_RESET, 1);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to program GPIOs\n");
+
+	msleep(20);
+
+	state->gc.parent = dev;
+	state->gc.label = i2c->name;
+	state->gc.owner = THIS_MODULE;
+	state->gc.base = -1;
+	state->gc.ngpio = NUM_GPIO;
+
+	/* it is output only */
+	state->gc.get = waveshare_gpio_gpio_get;
+	state->gc.set = waveshare_gpio_gpio_set;
+	state->gc.get_direction = waveshare_gpio_gpio_get_direction;
+	state->gc.can_sleep = true;
+
+	ret = devm_gpiochip_add_data(dev, &state->gc, state);
+	if (ret)
+		return dev_err_probe(dev, ret, "Failed to create gpiochip\n");
+
+	props.type = BACKLIGHT_RAW;
+	props.max_brightness = 255;
+	props.brightness = 255;
+	bl = devm_backlight_device_register(dev, dev_name(dev), dev, state,
+					    &waveshare_gpio_bl, &props);
+	return PTR_ERR_OR_ZERO(bl);
+}
+
+static const struct of_device_id waveshare_gpio_dt_ids[] = {
+	{ .compatible = "waveshare,dsi-touch-gpio" },
+	{},
+};
+MODULE_DEVICE_TABLE(of, waveshare_gpio_dt_ids);
+
+static struct i2c_driver waveshare_gpio_regulator_driver = {
+	.driver = {
+		.name = "waveshare-regulator",
+		.of_match_table = of_match_ptr(waveshare_gpio_dt_ids),
+	},
+	.probe = waveshare_gpio_probe,
+};
+
+module_i2c_driver(waveshare_gpio_regulator_driver);
+
+MODULE_DESCRIPTION("GPIO controller driver for Waveshare DSI touch panels");
+MODULE_LICENSE("GPL");

-- 
2.47.3

Re: [PATCH v5 0/2] drm/panel: support Waveshare DSI TOUCH kits

[Bartosz Golaszewski]

On Thu, 07 May 2026 12:01:31 +0300, Dmitry Baryshkov wrote:
> The Waveshare DSI TOUCH family of DSI panel kits feature different DSI
> video-mode panels, bundled with the separate controlling circuit,
> produing necessary voltages from the 3.3V and 5V supplies. Extend panel
> drivers to support those Waveshare panels and also add GPIO driver for
> the onboard control circuitry.
> 
> 
> [...]

Applied, thanks!

[1/2] dt-bindings: gpio: describe Waveshare GPIO controller
      https://git.kernel.org/brgl/c/8cd19f5560218bf263b8ffc622ceb4bc329b3bf5
[2/2] gpio: add GPIO controller found on Waveshare DSI TOUCH panels
      https://git.kernel.org/brgl/c/79f44c8acfe66ff8cbed5626e2535245cfcf43cf

Best regards,
-- 
Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>