Improve Logitech G535 support

README.md

@@ -22,7 +22,7 @@ talking. This differs from a simple loopback via PulseAudio as you won't have an
 - Logitech G533
   - Sidetone, Battery (for Wireless)
 - Logitech G535
-  - Sidetone (only tested on Linux)
+  - Sidetone, Battery, Inactive time (only tested on Linux)
 - Logitech G633 / G635 / G733 / G933 / G935
   - Sidetone, Battery (for Wireless), LED on/off
 - Logitech G930

src/devices/logitech_g535.c

@@ -3,15 +3,69 @@
 #include "logitech.h"
 
 #include <math.h>
+#include <stdio.h>
 #include <string.h>
-
-#define MSG_SIZE 20
+#include <unistd.h>
 
 static struct device device_g535;
 
 static const uint16_t PRODUCT_ID = 0x0ac4;
 
+// Based on manual measurements so the discharge curve used to generate these values aren't always
+// right, but it's good enough.
+// Based on the following measured values on a brand new headset (voltage, percentage) :
+// - 4175, 100
+// - 4135, 98
+// - 4124, 97
+// - 4109, 96
+// - 4106, 95
+// - 4066, 90
+// - 4055, 87
+// - 4047, 86
+// - 4036, 85
+// - 4025, 84
+// - 4000, 83
+// - 3985, 81
+// - 3974, 80
+// - 3971, 79
+// - 3963, 78
+// - 3945, 72
+// - 3934, 71
+// - 3916, 67
+// - 3894, 64
+// - 3887, 63
+// - 3872, 61
+// - 3839, 56
+// - 3817, 50
+// - 3806, 48
+// - 3788, 39
+// - 3774, 34
+// - 3766, 30
+// - 3752, 26
+// - 3741, 22
+// - 3730, 20
+// - 3719, 17
+// - 3701, 13
+// - 3688, 10
+// - 3679, 8
+// - 3675, 6
+// - 3664, 5
+// - 3640, 4
+// - 3600, 3
+// - 3540, 2
+// - 3485, 1
+// - 3445, 1
+// - 3405, 1
+// - 3339, 0
+// - 3325, 0
+// - 3310, 0
+static const int battery_estimate_percentages[] = { 100, 50, 30, 20, 5, 0 };
+static const int battery_estimate_voltages[]    = { 4175, 3817, 3766, 3730, 3664, 3310 };
+static const size_t battery_estimate_size       = 6;
+
 static int g535_send_sidetone(hid_device* device_handle, uint8_t num);
+static int g535_request_battery(hid_device* device_handle);
+static int g535_send_inactive_time(hid_device* device_handle, uint8_t num);
 
 void g535_init(struct device** device)
 {
@@ -21,21 +75,130 @@ void g535_init(struct device** device)
 
     strncpy(device_g535.device_name, "Logitech G535", sizeof(device_g535.device_name));
 
-    device_g535.capabilities                     = B(CAP_SIDETONE);
+    device_g535.capabilities                     = B(CAP_SIDETONE) | B(CAP_BATTERY_STATUS) | B(CAP_INACTIVE_TIME);
     device_g535.capability_details[CAP_SIDETONE] = (struct capability_detail) { .usagepage = 0xc, .usageid = 0x1, .interface = 3 };
-    device_g535.send_sidetone                    = &g535_send_sidetone;
+    /// TODO: usagepage and id may not be correct for battery status and inactive timer
+    device_g535.capability_details[CAP_BATTERY_STATUS] = (struct capability_detail) { .usagepage = 0xc, .usageid = 0x1, .interface = 3 };
+    device_g535.capability_details[CAP_INACTIVE_TIME]  = (struct capability_detail) { .usagepage = 0xc, .usageid = 0x1, .interface = 3 };
+
+    device_g535.send_sidetone      = &g535_send_sidetone;
+    device_g535.request_battery    = &g535_request_battery;
+    device_g535.send_inactive_time = &g535_send_inactive_time;
 
     *device = &device_g535;
 }
 
 static int g535_send_sidetone(hid_device* device_handle, uint8_t num)
 {
+    int ret = 0;
+
     num = map(num, 0, 128, 0, 100);
 
-    uint8_t set_sidetone_level[MSG_SIZE] = { 0x11, 0xff, 0x04, 0x1e, num };
+    uint8_t buf[HIDPP_LONG_MESSAGE_LENGTH] = { HIDPP_LONG_MESSAGE, HIDPP_DEVICE_RECEIVER, 0x04, 0x1d, num, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+
+    ret = hid_send_feature_report(device_handle, buf, sizeof(buf) / sizeof(buf[0]));
+    if (ret < 0) {
+        return ret;
+    }
+
+    ret = hid_read_timeout(device_handle, buf, HIDPP_LONG_MESSAGE_LENGTH, hsc_device_timeout);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (ret == 0) {
+        return HSC_READ_TIMEOUT;
+    }
+
+    // Headset offline
+    if (buf[2] == 0xFF) {
+        return BATTERY_UNAVAILABLE;
+    }
+
+    if (buf[4] != num) {
+        return HSC_ERROR;
+    }
+
+    return ret;
+}
+
+// inspired by logitech_g533.c
+static int g535_request_battery(hid_device* device_handle)
+{
+    int ret = 0;
+
+    // request battery voltage
+    uint8_t buf[HIDPP_LONG_MESSAGE_LENGTH] = { HIDPP_LONG_MESSAGE, HIDPP_DEVICE_RECEIVER, 0x05, 0x0d, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+
+    ret = hid_send_feature_report(device_handle, buf, sizeof(buf) / sizeof(buf[0]));
+    if (ret < 0) {
+        return ret;
+    }
+
+    ret = hid_read_timeout(device_handle, buf, HIDPP_LONG_MESSAGE_LENGTH, hsc_device_timeout);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (ret == 0) {
+        return HSC_READ_TIMEOUT;
+    }
+
+    // Headset offline
+    if (buf[2] == 0xFF) {
+        return BATTERY_UNAVAILABLE;
+    }
+
+    // 7th byte is state; 0x01 for idle, 0x03 for charging
+    uint8_t state = buf[6];
+    if (state == 0x03) {
+        return BATTERY_CHARGING;
+    }
+
+    // actual voltage is byte 4 and byte 5 combined together
+    const uint16_t voltage = (buf[4] << 8) | buf[5];
+
+    return spline_battery_level(battery_estimate_percentages, battery_estimate_voltages, battery_estimate_size, voltage);
+}
+
+static int g535_send_inactive_time(hid_device* device_handle, uint8_t num)
+{
+    // Accepted values are 0 (never), 1, 2, 5, 10, 15, 30
+    if (num > 30) {
+        printf("Device only accepts 0 (never) and numbers up to 30 for inactive time\n");
+        return HSC_OUT_OF_BOUNDS;
+    } else if (num > 2 && num < 5) { // let numbers smaller-inclusive 2 through, set numbers smaller than 5 to 5, and round the rest up to 30
+        num = 5;
+    } else if (num > 5) {
+        num = round_to_multiples(num, 5);
+    }
+
+    int ret = 0;
+
+    uint8_t buf[HIDPP_LONG_MESSAGE_LENGTH] = { HIDPP_LONG_MESSAGE, HIDPP_DEVICE_RECEIVER, 0x05, 0x2d, num, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
+
+    ret = hid_send_feature_report(device_handle, buf, sizeof(buf) / sizeof(buf[0]));
+    if (ret < 0) {
+        return ret;
+    }
+
+    ret = hid_read_timeout(device_handle, buf, HIDPP_LONG_MESSAGE_LENGTH, hsc_device_timeout);
+    if (ret < 0) {
+        return ret;
+    }
+
+    if (ret == 0) {
+        return HSC_READ_TIMEOUT;
+    }
+
+    // Headset offline
+    if (buf[2] == 0xFF) {
+        return BATTERY_UNAVAILABLE;
+    }
 
-    for (int i = 16; i < MSG_SIZE; i++)
-        set_sidetone_level[i] = 0;
+    if (buf[4] != num) {
+        return HSC_ERROR;
+    }
 
-    return hid_send_feature_report(device_handle, set_sidetone_level, MSG_SIZE);
+    return ret;
 }

src/utility.c

@@ -12,6 +12,32 @@ int map(int x, int in_min, int in_max, int out_min, int out_max)
     return (x - in_min) * (out_max - out_min) / (in_max - in_min) + out_min;
 }
 
+unsigned int round_to_multiples(unsigned int number, unsigned int multiple)
+{
+    return ((number + (multiple / 2)) / multiple) * multiple;
+}
+
+int spline_battery_level(const int p[], const int v[], const size_t size, uint16_t voltage)
+{
+    int percent = 0;
+
+    for (int i = 0; i < size; ++i) {
+        // if >= then 100%
+        if (voltage >= v[i]) {
+            percent = p[i];
+            break;
+        }
+
+        // if not last
+        if (i < size - 1 && voltage >= v[i + 1]) {
+            percent = p[i + 1] + (voltage - v[i + 1]) / (v[i] - v[i + 1]) * (p[i] - p[i + 1]);
+            break;
+        }
+    }
+
+    return percent;
+}
+
 float poly_battery_level(const double terms[], const size_t numterms, uint16_t voltage)
 {
     double t       = 1;

src/utility.h

@@ -9,14 +9,36 @@
  */
 int map(int x, int in_min, int in_max, int out_min, int out_max);
 
+/**
+ * @brief Rounds a given positive number to the nearest given multiple
+ *
+ * I.e. A number of 17 would be rounded to 15 if multiple is 5
+ *
+ * @param number A number to round
+ * @param multiple A multiple
+ * @return unsigned int the result rounded number
+ */
+unsigned int round_to_multiples(unsigned int number, unsigned int multiple);
+
+/**
+ * @brief This function calculates the estimate batttery level in percent using splines.
+ *
+ * @param p percentage values to be associated with voltage values
+ * @param v voltage values associated with percentage values
+ * @param size number of percentage and voltage associations
+ * @param voltage readings
+ * @return battery level in percent
+ */
+int spline_battery_level(const int p[], const int v[], const size_t size, uint16_t voltage);
+
 /**
  * @brief This function calculates the estimate batttery level in percent.
  *
  * To find the terms representing the polynominal discarge curve of the
  * battery an solver like https://arachnoid.com/polysolve/ can be used.
  *
- * @param array polynominal terms for the battery discharge curve
- * @param number of terms
+ * @param terms polynominal terms for the battery discharge curve
+ * @param numterms number of terms
  * @param voltage readings
  * @return battery level in percent
  */