From 0f78eb6ce67962a4147dce37cc4f8538d44b36d7 Mon Sep 17 00:00:00 2001
From: Peter Wu <peter@lekensteyn.nl>
Date: Mon, 24 Mar 2014 13:25:49 +0100
Subject: unifying: implement BatteryStatus

Battery percentage is fuzzy... ok.

Signed-off-by: Peter Wu <peter@lekensteyn.nl>
---
 hw/usb/hid-logitech-hidpp20.c | 47 +++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 47 insertions(+)

(limited to 'hw/usb/hid-logitech-hidpp20.c')

diff --git a/hw/usb/hid-logitech-hidpp20.c b/hw/usb/hid-logitech-hidpp20.c
index 3c664cc089..026dd587be 100644
--- a/hw/usb/hid-logitech-hidpp20.c
+++ b/hw/usb/hid-logitech-hidpp20.c
@@ -186,11 +186,58 @@ static HIDPP20_FEATURE(feat_devicename)
     }
 }
 
+static uint8_t calc_battery_percent(LHidDevice *hd, uint8_t level)
+{
+    uint8_t nlevels = hd->battery.nlevels;
+
+    assert(nlevels >= 2);
+    assert(level >= 1 && level <= nlevels);
+    if (nlevels == 2) {
+        switch (level) {
+        case 2:     return 90;
+        default:    return  5;
+        }
+    } else if (nlevels < 10 || !(hd->battery.flags & BAT_FLAG_ENABLE_MILEAGE)) {
+        switch (4 * level / nlevels) {
+        case 4:     return 90;
+        case 3:     return 50;
+        case 2:     return 20;
+        default:    return  5;
+        }
+    }
+
+    return 100 * level / nlevels;
+}
+
+static HIDPP20_FEATURE(feat_batterystatus)
+{
+    switch (fn) {
+    case 0: /* BatteryLevel = GetBatteryLevelStatus() */
+        params[0] = calc_battery_percent(hd, hd->battery.level);
+        if (hd->battery.level > 0 && hd->battery.status == BAT_STS_DISCHARGING) {
+            params[1] = calc_battery_percent(hd, hd->battery.level - 1);
+        } else {
+            params[1] = 0;
+        }
+        params[2] = hd->battery.status;
+        return 2;
+    case 1: /* LevelList[] = GetBatteryCapacity() */
+        params[0] = hd->battery.nlevels;
+        params[1] = hd->battery.flags;
+        params[2] = params[3] = 0; /* TODO: nominal battery life */
+        params[4] = hd->battery.critical_perc;
+        return 5;
+    default:
+        return -HIDPP20_ERR_CODE_INVALID_FUNCTION_ID;
+    }
+}
+
 /* root feature not included! */
 static const HidppFeature features_m525[] = {
     { 0x0001, 0, feat_featureset            },
     { 0x0003, 0, feat_devicefwversion       },
     { 0x0005, 0, feat_devicename            },
+    { 0x1000, 0, feat_batterystatus         },
 };
 
 void hidpp20_init_features(LHidDevice *hd) {
-- 
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