usb_hid: add support for Battery Strength

This allows rockbox to report its battery status through the
HID Battery Strength method that is available through the
Device Controls usage page.

Change-Id: Ia7a7dd9b9d476dd9df5a5f5becabc5ae823e9a89

4 files changed, 82 insertions, 1 deletions

diff --git a/firmware/export/powermgmt.h b/firmware/export/powermgmt.h
index 235f5302f9..b7ca6772f3 100644
--- a/firmware/export/powermgmt.h
+++ b/firmware/export/powermgmt.h
@@ -166,6 +166,9 @@ void set_poweroff_timeout(int timeout);
 void set_battery_capacity(int capacity); /* set local battery capacity value */
 int  get_battery_capacity(void); /* get local battery capacity value */
 void set_battery_type(int type); /* set local battery type */
+#ifdef USB_ENABLE_HID
+void set_battery_reporting(bool enable);
+#endif
 
 void set_sleeptimer_duration(int minutes);
 int get_sleep_timer(void);
diff --git a/firmware/powermgmt.c b/firmware/powermgmt.c
index 6cac300cdf..969d6167da 100644
--- a/firmware/powermgmt.c
+++ b/firmware/powermgmt.c
@@ -48,6 +48,9 @@
 #if (CONFIG_PLATFORM & PLATFORM_HOSTED)
 #include <time.h>
 #endif
+#ifdef USB_ENABLE_HID
+#include "usbstack/usb_hid.h"
+#endif
 
 #if (defined(IAUDIO_X5) || defined(IAUDIO_M5) || defined(COWON_D2)) \
     && !defined (SIMULATOR)
@@ -637,6 +640,17 @@ static void collect_power_history(void)
     power_history[0] = power_hist_item();
 }
 
+#ifdef USB_ENABLE_HID
+static bool battery_reporting = false;
+static int battery_report_percent = -1;
+
+void set_battery_reporting(bool enable)
+{
+    battery_reporting = enable;
+    battery_report_percent = -1;
+}
+#endif
+
 /*
  * Monitor the presence of a charger and perform critical frequent steps
  * such as running the battery voltage filter.
@@ -750,6 +764,13 @@ static void power_thread(void)
             next_power_hist += HZ*60;
             collect_power_history();
         }
+
+#ifdef USB_ENABLE_HID
+        if (battery_reporting && battery_report_percent != battery_percent) {
+            battery_report_percent = battery_percent;
+            usb_hid_send(HID_USAGE_PAGE_GENERIC_DEVICE_CONTROLS, battery_report_percent);
+        }
+#endif
     }
 } /* power_thread */
 
diff --git a/firmware/usbstack/usb_hid.c b/firmware/usbstack/usb_hid.c
index ed0816395a..0b672e6452 100644
--- a/firmware/usbstack/usb_hid.c
+++ b/firmware/usbstack/usb_hid.c
@@ -23,6 +23,7 @@
 #include "usb_core.h"
 #include "usb_drv.h"
 #include "kernel.h"
+#include "powermgmt.h"
 #include "usb_hid.h"
 #include "usb_class_driver.h"
 /*#define LOGF_ENABLE*/
@@ -109,6 +110,7 @@ typedef enum
 #ifdef HAVE_USB_HID_MOUSE
     REPORT_ID_MOUSE,
 #endif
+    REPORT_ID_BACKGROUND,
     REPORT_ID_COUNT,
 } report_id_t;
 
@@ -450,6 +452,15 @@ static uint8_t buf_set_mouse(unsigned char *buf, int id)
 }
 #endif /* HAVE_USB_HID_MOUSE */
 
+#define BUF_LEN_BACKGROUND 1
+static uint8_t buf_set_background(unsigned char *buf, int id)
+{
+    memset(buf, 0, BUF_LEN_BACKGROUND);
+    buf[0] = (uint8_t)id;
+
+    return BUF_LEN_BACKGROUND;
+}
+
 static size_t descriptor_report_get(unsigned char *dest)
 {
     unsigned char *report = dest;
@@ -551,6 +562,24 @@ static size_t descriptor_report_get(unsigned char *dest)
     PACK_VAL(report, END_COLLECTION);
 #endif /* HAVE_USB_HID_MOUSE */
 
+    /* Background controls */
+    usb_hid_report = &usb_hid_reports[REPORT_ID_BACKGROUND];
+    usb_hid_report->usage_page = HID_USAGE_PAGE_GENERIC_DEVICE_CONTROLS;
+    usb_hid_report->buf_set = buf_set_background;
+    usb_hid_report->is_key_released = 0;
+
+    pack_parameter(&report, 0, 1, USAGE_PAGE, HID_USAGE_PAGE_GENERIC_DEVICE_CONTROLS);
+    pack_parameter(&report, 0, 0, CONSUMER_USAGE, HID_GENERIC_DEVICE_BACKGROUND_CONTROLS);
+    pack_parameter(&report, 0, 1, COLLECTION, COLLECTION_APPLICATION);
+    pack_parameter(&report, 0, 1, REPORT_ID, REPORT_ID_BACKGROUND);
+    pack_parameter(&report, 0, 0, CONSUMER_USAGE, HID_GENERIC_DEVICE_BATTERY_STRENGTH);
+    pack_parameter(&report, 0, 1, LOGICAL_MINIMUM, 0);
+    pack_parameter(&report, 0, 1, LOGICAL_MAXIMUM, 100);
+    pack_parameter(&report, 0, 1, REPORT_SIZE, 8);
+    pack_parameter(&report, 0, 1, REPORT_COUNT, 1);
+    pack_parameter(&report, 0, 1, INPUT, MAIN_ITEM_VARIABLE);
+    PACK_VAL(report, END_COLLECTION);
+
     return (size_t)(report - dest);
 }
 
@@ -591,9 +620,9 @@ int usb_hid_get_config_descriptor(unsigned char *dest, int max_packet_size)
 void usb_hid_init_connection(void)
 {
     logf("hid: init connection");
-
     active = true;
     currently_sending = false;
+    set_battery_reporting(true);
 }
 
 /* called by usb_core_init() */
@@ -614,6 +643,7 @@ void usb_hid_init(void)
 void usb_hid_disconnect(void)
 {
     logf("hid: disconnect");
+    set_battery_reporting(false);
     active = false;
     currently_sending = false;
 }
diff --git a/firmware/usbstack/usb_hid_usage_tables.h b/firmware/usbstack/usb_hid_usage_tables.h
index d23c704eae..538463e5a3 100644
--- a/firmware/usbstack/usb_hid_usage_tables.h
+++ b/firmware/usbstack/usb_hid_usage_tables.h
@@ -120,6 +120,33 @@ typedef enum usage_page
 #define HID_GENERIC_DESKTOP_SYSTEM_DISPLAY_SWAP_PRIMARY_SECONDARY         0xB6
 #define HID_GENERIC_DESKTOP_SYSTEM_DISPLAY_LCD_AUTOSCALE                  0xB7
 
+/* Generic Device Controls Page (0x06) */
+#define HID_GENERIC_DEVICE_UNDEFINED                                      0x00
+#define HID_GENERIC_DEVICE_BACKGROUND_CONTROLS                            0x01
+#define HID_GENERIC_DEVICE_BATTERY_STRENGTH                               0x20
+#define HID_GENERIC_DEVICE_WIRELESS_CHANNEL                               0x21
+#define HID_GENERIC_DEVICE_WIRELESS_ID                                    0x22
+#define HID_GENERIC_DEVICE_DISCOVER_WIRELESS_CHANNEL                      0x23
+#define HID_GENERIC_DEVICE_SECURITY_CODE_CHARACTER_ENTERED                0x24
+#define HID_GENERIC_DEVICE_SECURITY_CODE_CHARACTER_ERASED                 0x25
+#define HID_GENERIC_DEVICE_SECURITY_CODE_CLEARED                          0x26
+#define HID_GENERIC_DEVICE_SEQUENCE_ID                                    0x27
+#define HID_GENERIC_DEVICE_SEQUENCE_ID_RESET                              0x28
+#define HID_GENERIC_DEVICE_RF_SIGNAL_STRENGTH                             0x29
+#define HID_GENERIC_DEVICE_SOFTWARE_VERSION                               0x2A
+#define HID_GENERIC_DEVICE_PROTOCOL_VERSION                               0x2B
+#define HID_GENERIC_DEVICE_HARDWARE_VERSION                               0x2C
+#define HID_GENERIC_DEVICE_MAJOR                                          0x2D
+#define HID_GENERIC_DEVICE_MINOR                                          0x2E
+#define HID_GENERIC_DEVICE_REVISION                                       0x2F
+#define HID_GENERIC_DEVICE_HANDEDNESS                                     0x30
+#define HID_GENERIC_DEVICE_EITHER_HAND                                    0x31
+#define HID_GENERIC_DEVICE_LEFT_HAND                                      0x32
+#define HID_GENERIC_DEVICE_RIGHT_HAND                                     0x33
+#define HID_GENERIC_DEVICE_BOTH_HANDS                                     0x34
+#define HID_GENERIC_DEVICE_GRIP_POSE_OFFSET                               0x40
+#define HID_GENERIC_DEVICE_POINTER_POSE_OFFSET                            0x41
+
 /* Keyboard/Keypad Page (0x07) */
 #define HID_KEYBOARD_RESERVED                                             0x00
 #define HID_KEYBOARD_ERROR_ROLLOVER                                       0x01