hidpp20: implement 0x2201, adjustable dpi

only the getter right now.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>

src/driver-logitech-unifying.c

@@ -49,6 +49,7 @@
 #include "libratbag-hidraw.h"
 
 #define HIDPP_CAP_RESOLUTION_2200			(1 << 0)
+#define HIDPP_CAP_SWITCHABLE_RESOLUTION_2201		(1 << 1)
 
 struct unifying_data {
 	unsigned proto_major;
@@ -100,6 +101,7 @@ static int
 unifying_init_feature(struct ratbag_device *device, uint16_t feature)
 {
 	struct unifying_data *drv_data = ratbag_get_drv_data(device);
+	struct ratbag *ratbag = device->ratbag;
 	int rc;
 
 	switch (feature) {
@@ -115,11 +117,28 @@ unifying_init_feature(struct ratbag_device *device, uint16_t feature)
 		rc = hidpp20_mousepointer_get_mousepointer_info(device, &resolution, &flags);
 		if (rc)
 			return rc;
-		log_info(device->ratbag, "device is at %d dpi\n", resolution);
+		log_info(ratbag, "device is at %d dpi\n", resolution);
+		break;
+	}
+	case 0x2201: {
+		struct hidpp20_sensor *sensors;
+
+		log_info(ratbag, "device has adjustable dpi\n");
+		rc = hidpp20_adjustable_dpi_get_sensors(device, &sensors);
+		if (rc < 0)
+			return rc;
+		if (rc > 0)
+			log_info(ratbag,
+				 "device is at %d dpi (variable between %d and %d).\n",
+				 sensors[0].dpi,
+				 sensors[0].dpi_min,
+				 sensors[0].dpi_max);
+		free(sensors);
+		drv_data->capabilities |= HIDPP_CAP_SWITCHABLE_RESOLUTION_2201;
 		break;
 	}
 	default:
-		log_info(device->ratbag, "unknown feature 0x%04x\n", feature);
+		log_debug(device->ratbag, "unknown feature 0x%04x\n", feature);
 	}
 	return 0;
 }

src/hidpp20.c

@@ -29,6 +29,7 @@
  *   https://drive.google.com/folderview?id=0BxbRzx7vEV7eWmgwazJ3NUFfQ28&usp=sharing
  */
 
+#include <assert.h>
 #include <errno.h>
 #include <stdio.h>
 #include <string.h>
@@ -119,6 +120,12 @@ out_err:
 	return ret;
 }
 
+static inline uint16_t
+hidpp20_get_unaligned_u16(uint8_t *buf)
+{
+	return (buf[0] << 8) | buf[1];
+}
+
 /* -------------------------------------------------------------------------- */
 /* 0x0000: Root                                                               */
 /* -------------------------------------------------------------------------- */
@@ -330,3 +337,159 @@ hidpp20_mousepointer_get_mousepointer_info(struct ratbag_device *device,
 
 	return 0;
 }
+
+/* -------------------------------------------------------------------------- */
+/* 0x2201: Adjustable DPI                                                     */
+/* -------------------------------------------------------------------------- */
+
+#define HIDPP_PAGE_ADJUSTABLE_DPI			0x2201
+
+#define CMD_ADJUSTABLE_DPI_GET_SENSOR_COUNT		0x08
+#define CMD_ADJUSTABLE_DPI_GET_SENSOR_DPI_LIST		0x18
+#define CMD_ADJUSTABLE_DPI_GET_SENSOR_DPI		0x28
+#define CMD_ADJUSTABLE_DPI_SET_SENSOR_DPI		0x38
+
+static int
+hidpp20_adjustable_dpi_get_count(struct ratbag_device *device, uint8_t reg)
+{
+	int rc;
+	union hidpp20_message msg = {
+		.msg.report_id = REPORT_ID_LONG,
+		.msg.device_idx = 0xff,
+		.msg.sub_id = reg,
+		.msg.address = CMD_ADJUSTABLE_DPI_GET_SENSOR_COUNT,
+	};
+
+	rc = hidpp20_request_command(device, &msg);
+	if (rc)
+		return rc;
+
+	return msg.msg.parameters[0];
+}
+
+static int
+hidpp20_adjustable_dpi_get_dpi_list(struct ratbag_device *device,
+				    uint8_t reg,
+				    struct hidpp20_sensor *sensor)
+{
+	int rc;
+	unsigned i = 1, dpi_index = 0;
+	union hidpp20_message msg = {
+		.msg.report_id = REPORT_ID_LONG,
+		.msg.device_idx = 0xff,
+		.msg.sub_id = reg,
+		.msg.address = CMD_ADJUSTABLE_DPI_GET_SENSOR_DPI_LIST,
+		.msg.parameters[0] = sensor->index,
+	};
+
+	rc = hidpp20_request_command(device, &msg);
+	if (rc)
+		return rc;
+
+	sensor->dpi_min = 0xffff;
+
+	sensor->index = msg.msg.parameters[0];
+	while (i < LONG_MESSAGE_LENGTH - 1 &&
+	       hidpp20_get_unaligned_u16(&msg.msg.parameters[i]) != 0) {
+		uint16_t value = hidpp20_get_unaligned_u16(&msg.msg.parameters[i]);
+
+		if (value > 0xe000) {
+			sensor->dpi_steps = value - 0xe000;
+		} else {
+			sensor->dpi_min = value < sensor->dpi_min ? value : sensor->dpi_min;
+			sensor->dpi_max = value > sensor->dpi_max ? value : sensor->dpi_max;
+			sensor->dpi_list[dpi_index++] = value;
+		}
+		assert(sensor->dpi_list[dpi_index] == 0x0000);
+		i += 2;
+	}
+
+	return 0;
+}
+
+
+static int
+hidpp20_adjustable_dpi_get_dpi(struct ratbag_device *device,
+			       uint8_t reg,
+			       struct hidpp20_sensor *sensor)
+{
+	int rc;
+	union hidpp20_message msg = {
+		.msg.report_id = REPORT_ID_LONG,
+		.msg.device_idx = 0xff,
+		.msg.sub_id = reg,
+		.msg.address = CMD_ADJUSTABLE_DPI_GET_SENSOR_DPI,
+		.msg.parameters[0] = sensor->index,
+	};
+
+	rc = hidpp20_request_command(device, &msg);
+	if (rc)
+		return rc;
+
+	sensor->dpi = hidpp20_get_unaligned_u16(&msg.msg.parameters[1]);
+	sensor->default_dpi = hidpp20_get_unaligned_u16(&msg.msg.parameters[3]);
+
+	return 0;
+}
+
+int hidpp20_adjustable_dpi_get_sensors(struct ratbag_device *device,
+				       struct hidpp20_sensor **sensors_list)
+{
+	uint8_t feature_index, feature_type, feature_version;
+	struct hidpp20_sensor *s_list, *sensor;
+	uint8_t num_sensors;
+	unsigned i;
+	int rc;
+
+
+	rc = hidpp_root_get_feature(device,
+				    HIDPP_PAGE_ADJUSTABLE_DPI,
+				    &feature_index,
+				    &feature_type,
+				    &feature_version);
+	if (rc)
+		return rc;
+
+	rc = hidpp20_adjustable_dpi_get_count(device, feature_index);
+	if (rc < 0)
+		return rc;
+
+	num_sensors = rc;
+	if (num_sensors == 0) {
+		*sensors_list = NULL;
+		return 0;
+	}
+
+	s_list = zalloc(num_sensors * sizeof(struct hidpp20_sensor));
+	if (!s_list)
+		return -ENOMEM;
+
+	for (i = 0; i < num_sensors; i++) {
+		sensor = &s_list[i];
+		sensor->index = i;
+		rc = hidpp20_adjustable_dpi_get_dpi_list(device,
+							 feature_index,
+							 sensor);
+		if (rc)
+			goto err;
+
+		rc = hidpp20_adjustable_dpi_get_dpi(device, feature_index, sensor);
+		if (rc)
+			goto err;
+
+		log_debug(device->ratbag,
+			  "sensor %d: current dpi: %d (default: %d) min: %d max: %d steps: %d\n",
+			  sensor->index,
+			  sensor->dpi,
+			  sensor->default_dpi,
+			  sensor->dpi_min,
+			  sensor->dpi_max,
+			  sensor->dpi_steps);
+	}
+
+	*sensors_list = s_list;
+	return num_sensors;
+err:
+	free(s_list);
+	return rc;
+}

src/hidpp20.h

@@ -94,4 +94,30 @@ int hidpp20_mousepointer_get_mousepointer_info(struct ratbag_device *device,
 					       uint16_t *resolution,
 					       uint8_t *flags);
 
+/* -------------------------------------------------------------------------- */
+/* 0x2201: Adjustable DPI                                                     */
+/* -------------------------------------------------------------------------- */
+
+/**
+ * either dpi_steps is not null or the values are stored in the null terminated
+ * array dpi_list.
+ */
+struct hidpp20_sensor {
+	uint8_t index;
+	uint16_t dpi;
+	uint16_t dpi_min;
+	uint16_t dpi_max;
+	uint16_t dpi_steps;
+	uint16_t default_dpi;
+	uint16_t dpi_list[LONG_MESSAGE_LENGTH / 2 + 1];
+};
+
+/**
+ * allocates a list of sensors that has to be freed by the caller.
+ *
+ * returns the elements in the list or a negative error
+ */
+int hidpp20_adjustable_dpi_get_sensors(struct ratbag_device *device,
+				       struct hidpp20_sensor **sensors_list);
+
 #endif /* HIDPP_20_H */