input: add a pat912x driver

Add an initial input driver for the PixArt PAT9125EL, just core
functionalities for now, will add more configuration properties at a
later stage.

Signed-off-by: Fabio Baltieri <fabiobaltieri@google.com>

drivers/input/CMakeLists.txt

@@ -18,6 +18,7 @@ zephyr_library_sources_ifdef(CONFIG_INPUT_GT911 input_gt911.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_ITE_IT8XXX2_KBD input_ite_it8xxx2_kbd.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_KBD_MATRIX input_kbd_matrix.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_NPCX_KBD input_npcx_kbd.c)
+zephyr_library_sources_ifdef(CONFIG_INPUT_PAT912X input_pat912x.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_STMPE811 input_stmpe811.c)
 zephyr_library_sources_ifdef(CONFIG_INPUT_XPT2046 input_xpt2046.c)
 # zephyr-keep-sorted-stop

drivers/input/Kconfig

@@ -20,6 +20,7 @@ source "drivers/input/Kconfig.gt911"
 source "drivers/input/Kconfig.it8xxx2"
 source "drivers/input/Kconfig.kbd_matrix"
 source "drivers/input/Kconfig.npcx"
+source "drivers/input/Kconfig.pat912x"
 source "drivers/input/Kconfig.sdl"
 source "drivers/input/Kconfig.stmpe811"
 source "drivers/input/Kconfig.xpt2046"

drivers/input/Kconfig.pat912x

@@ -0,0 +1,10 @@
+# Copyright 2024 Google LLC
+# SPDX-License-Identifier: Apache-2.0
+
+config INPUT_PAT912X
+	bool "PAT912X miniature optical navigation chip input driver"
+	default y
+	depends on DT_HAS_PIXART_PAT912X_ENABLED
+	select I2C
+	help
+	  PAT912X miniature optical navigation chip input driver

drivers/input/input_pat912x.c

@@ -0,0 +1,268 @@
+/*
+ * Copyright 2024 Google LLC
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#define DT_DRV_COMPAT pixart_pat912x
+
+#include <stdint.h>
+#include <stdlib.h>
+
+#include <zephyr/device.h>
+#include <zephyr/drivers/gpio.h>
+#include <zephyr/drivers/i2c.h>
+#include <zephyr/input/input.h>
+#include <zephyr/kernel.h>
+#include <zephyr/logging/log.h>
+#include <zephyr/pm/device.h>
+#include <zephyr/pm/device_runtime.h>
+#include <zephyr/sys/byteorder.h>
+#include <zephyr/sys/util.h>
+
+LOG_MODULE_REGISTER(input_pat912x, CONFIG_INPUT_LOG_LEVEL);
+
+#define PAT912X_PRODUCT_ID1	0x00
+#define PAT912X_PRODUCT_ID2	0x01
+#define PAT912X_MOTION_STATUS	0x02
+#define PAT912X_DELTA_X_LO	0x03
+#define PAT912X_DELTA_Y_LO	0x04
+#define PAT912X_OPERATION_MODE	0x05
+#define PAT912X_CONFIGURATION	0x06
+#define PAT912X_WRITE_PROTECT	0x09
+#define PAT912X_SLEEP1		0x0a
+#define PAT912X_SLEEP2		0x0b
+#define PAT912X_RES_X		0x0d
+#define PAT912X_RES_Y		0x0e
+#define PAT912X_DELTA_XY_HI	0x12
+#define PAT912X_SHUTTER		0x14
+#define PAT912X_FRAME_AVG	0x17
+#define PAT912X_ORIENTATION	0x19
+
+#define PRODUCT_ID_PAT9125EL 0x3191
+
+#define CONFIGURATION_RESET 0x97
+#define CONFIGURATION_CLEAR 0x17
+#define CONFIGURATION_PD_ENH BIT(3)
+#define WRITE_PROTECT_ENABLE 0x00
+#define WRITE_PROTECT_DISABLE 0x5a
+#define MOTION_STATUS_MOTION BIT(7)
+
+#define PAT912X_DATA_SIZE_BITS 12
+
+#define RESET_DELAY_MS 2
+
+struct pat912x_config {
+	struct i2c_dt_spec i2c;
+	struct gpio_dt_spec motion_gpio;
+	int32_t axis_x;
+	int32_t axis_y;
+};
+
+struct pat912x_data {
+	const struct device *dev;
+	struct k_work motion_work;
+	struct gpio_callback motion_cb;
+};
+
+static void pat912x_motion_work_handler(struct k_work *work)
+{
+	struct pat912x_data *data = CONTAINER_OF(
+			work, struct pat912x_data, motion_work);
+	const struct device *dev = data->dev;
+	const struct pat912x_config *cfg = dev->config;
+	int32_t x, y;
+	uint8_t val;
+	uint8_t xy[2];
+	int ret;
+
+	ret = i2c_reg_read_byte_dt(&cfg->i2c, PAT912X_MOTION_STATUS, &val);
+	if (ret < 0) {
+		return;
+	}
+
+	if ((val & MOTION_STATUS_MOTION) == 0x00) {
+		return;
+	}
+
+	ret = i2c_burst_read_dt(&cfg->i2c, PAT912X_DELTA_X_LO, xy, sizeof(xy));
+	if (ret < 0) {
+		return;
+	}
+	x = xy[0];
+	y = xy[1];
+
+	ret = i2c_reg_read_byte_dt(&cfg->i2c, PAT912X_DELTA_XY_HI, &val);
+	if (ret < 0) {
+		return;
+	}
+	y |= (val << 8) & 0xf00;
+	x |= (val << 4) & 0xf00;
+
+	x = sign_extend(x, PAT912X_DATA_SIZE_BITS - 1);
+	y = sign_extend(y, PAT912X_DATA_SIZE_BITS - 1);
+
+	LOG_DBG("x=%4d y=%4d", x, y);
+
+	if (cfg->axis_x >= 0) {
+		bool sync = cfg->axis_y < 0;
+
+		input_report_rel(data->dev, cfg->axis_x, x, sync, K_FOREVER);
+	}
+
+	if (cfg->axis_y >= 0) {
+		input_report_rel(data->dev, cfg->axis_y, y, true, K_FOREVER);
+	}
+
+	/* Trigger one more scan in case more data is available. */
+	k_work_submit(&data->motion_work);
+}
+
+static void pat912x_motion_handler(const struct device *gpio_dev,
+				   struct gpio_callback *cb,
+				   uint32_t pins)
+{
+	struct pat912x_data *data = CONTAINER_OF(
+			cb, struct pat912x_data, motion_cb);
+
+	k_work_submit(&data->motion_work);
+}
+
+static int pat912x_configure(const struct device *dev)
+{
+	const struct pat912x_config *cfg = dev->config;
+	uint8_t id[2];
+	int ret;
+
+	ret = i2c_burst_read_dt(&cfg->i2c, PAT912X_PRODUCT_ID1, id, sizeof(id));
+	if (ret < 0) {
+		return ret;
+	}
+
+	if (sys_get_be16(id) != PRODUCT_ID_PAT9125EL) {
+		LOG_ERR("Invalid product id: %04x", sys_get_be16(id));
+		return -ENOTSUP;
+	}
+
+	/* Software reset */
+
+	i2c_reg_write_byte_dt(&cfg->i2c, PAT912X_CONFIGURATION, CONFIGURATION_RESET);
+	/* no ret value check, the device NACKs */
+
+	k_sleep(K_MSEC(RESET_DELAY_MS));
+
+	ret = i2c_reg_write_byte_dt(&cfg->i2c, PAT912X_CONFIGURATION, CONFIGURATION_CLEAR);
+	if (ret < 0) {
+		return ret;
+	}
+
+	return 0;
+}
+
+static int pat912x_init(const struct device *dev)
+{
+	const struct pat912x_config *cfg = dev->config;
+	struct pat912x_data *data = dev->data;
+	int ret;
+
+	if (!i2c_is_ready_dt(&cfg->i2c)) {
+		LOG_ERR("%s is not ready", cfg->i2c.bus->name);
+		return -ENODEV;
+	}
+
+	data->dev = dev;
+
+	k_work_init(&data->motion_work, pat912x_motion_work_handler);
+
+	if (!gpio_is_ready_dt(&cfg->motion_gpio)) {
+		LOG_ERR("%s is not ready", cfg->motion_gpio.port->name);
+		return -ENODEV;
+	}
+
+	ret = gpio_pin_configure_dt(&cfg->motion_gpio, GPIO_INPUT);
+	if (ret != 0) {
+		LOG_ERR("Motion pin configuration failed: %d", ret);
+		return ret;
+	}
+
+	ret = gpio_pin_interrupt_configure_dt(&cfg->motion_gpio,
+					      GPIO_INT_EDGE_TO_ACTIVE);
+	if (ret != 0) {
+		LOG_ERR("Motion interrupt configuration failed: %d", ret);
+		return ret;
+	}
+
+	gpio_init_callback(&data->motion_cb, pat912x_motion_handler,
+			   BIT(cfg->motion_gpio.pin));
+
+	ret = pat912x_configure(dev);
+	if (ret != 0) {
+		LOG_ERR("Device configuration failed: %d", ret);
+		return ret;
+	}
+
+	ret = gpio_add_callback_dt(&cfg->motion_gpio, &data->motion_cb);
+	if (ret < 0) {
+		LOG_ERR("Could not set motion callback: %d", ret);
+		return ret;
+	}
+
+	/* Trigger an initial read to clear any pending motion status.*/
+	k_work_submit(&data->motion_work);
+
+	ret = pm_device_runtime_enable(dev);
+	if (ret < 0) {
+		LOG_ERR("Failed to enable runtime power management");
+		return ret;
+	}
+
+	return 0;
+}
+
+#ifdef CONFIG_PM_DEVICE
+static int pat912x_pm_action(const struct device *dev,
+			     enum pm_device_action action)
+{
+	const struct pat912x_config *cfg = dev->config;
+	uint8_t val;
+	int ret;
+
+	switch (action) {
+	case PM_DEVICE_ACTION_SUSPEND:
+		val = CONFIGURATION_PD_ENH;
+		break;
+	case PM_DEVICE_ACTION_RESUME:
+		val = 0;
+		break;
+	default:
+		return -ENOTSUP;
+	}
+
+	ret = i2c_reg_update_byte_dt(&cfg->i2c, PAT912X_CONFIGURATION,
+				     CONFIGURATION_PD_ENH, val);
+	if (ret < 0) {
+		return ret;
+	}
+
+	return 0;
+}
+#endif
+
+#define PAT912X_INIT(n)								\
+	static const struct pat912x_config pat912x_cfg_##n = {			\
+		.i2c = I2C_DT_SPEC_INST_GET(n),					\
+		.motion_gpio = GPIO_DT_SPEC_INST_GET(n, motion_gpios),		\
+		.axis_x = DT_INST_PROP_OR(n, zephyr_axis_x, -1),		\
+		.axis_y = DT_INST_PROP_OR(n, zephyr_axis_y, -1),		\
+	};									\
+										\
+	static struct pat912x_data pat912x_data_##n;				\
+										\
+	PM_DEVICE_DT_INST_DEFINE(n, pat912x_pm_action);				\
+										\
+	DEVICE_DT_INST_DEFINE(n, pat912x_init, PM_DEVICE_DT_INST_GET(n),	\
+			      &pat912x_data_##n, &pat912x_cfg_##n,		\
+			      POST_KERNEL, CONFIG_INPUT_INIT_PRIORITY,		\
+			      NULL);
+
+DT_INST_FOREACH_STATUS_OKAY(PAT912X_INIT)

dts/bindings/input/pixart,pat912x.yaml

@@ -0,0 +1,27 @@
+# Copyright 2024 Google LLC
+# SPDX-License-Identifier: Apache-2.0
+
+description: PAT9125EL Miniature Optical Navigation Chip
+
+compatible: "pixart,pat912x"
+
+include: i2c-device.yaml
+
+properties:
+  motion-gpios:
+    type: phandle-array
+    required: true
+    description:
+      GPIO connected to the motion pin, active low.
+
+  zephyr,axis-x:
+    type: int
+    description: |
+      The input code for the X axis to report for the device, typically any of
+      INPUT_REL_*. No report produced for the device X axis if unspecified.
+
+  zephyr,axis-y:
+    type: int
+    description: |
+      The input code for the Y axis to report for the device, typically any of
+      INPUT_REL_*. No report produced for the device Y axis if unspecified.

tests/drivers/build_all/input/app.overlay

@@ -197,6 +197,14 @@
 				touch-average-control = <1>;
 				tracking-index = <0>;
 			};
+
+			pat@5 {
+				compatible = "pixart,pat912x";
+				reg = <0x5>;
+				motion-gpios = <&test_gpio 0 0>;
+				zephyr,axis-x = <0>;
+				zephyr,axis-y = <1>;
+			};
 		};
 
 		spi@2 {