Initial commit for the Sony NWZ linux port

SUPPORTED SERIES:
- NWZ-E450
- NWZ-E460
- NWZ-E470
- NWZ-E580
- NWZ-A10

NOTES:
- bootloader makefile convert an extra font to be installed alongside the bootloader
  since sysfont is way too small
- the toolsicon bitmap comes from the Oxygen iconset
- touchscreen driver is untested

TODO:
- implement audio routing driver (pcm is handled by pcm-alsa)
- fix playback: it crashes on illegal instruction in DEBUG builds
- find out why the browser starts at / instead of /contents
- implement radio support
- implement return to OF for usb handling
- calibrate battery curve (NB: of can report a battery level on a 0-5 scale but
  probabl don't want to use that ?)
- implement simulator build (we need a nice image of the player)
- figure out if we can detect jack removal

POTENTIAL TODOS:
- try to build a usb serial gadget and gdbserver

Change-Id: Ic77d71e0651355d47cc4e423a40fb64a60c69a80

firmware/target/hosted/sonynwz/powermgmt-nwz.c

@@ -0,0 +1,69 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ *
+ * Copyright (C) 2016 Amaury Pouly
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
+ * KIND, either express or implied.
+ *
+ ****************************************************************************/
+#include "powermgmt.h"
+#include "power.h"
+#include "power-nwz.h"
+
+const unsigned short battery_level_dangerous[BATTERY_TYPES_COUNT] =
+{
+    3470
+};
+
+/* the OF shuts down at this voltage */
+const unsigned short battery_level_shutoff[BATTERY_TYPES_COUNT] =
+{
+    3450
+};
+
+/* voltages (millivolt) of 0%, 10%, ... 100% when charging disabled */
+const unsigned short percent_to_volt_discharge[BATTERY_TYPES_COUNT][11] =
+{
+    { 3450, 3502, 3550, 3587, 3623, 3669, 3742, 3836, 3926, 4026, 4200 }
+};
+
+/* voltages (millivolt) of 0%, 10%, ... 100% when charging enabled */
+const unsigned short const percent_to_volt_charge[11] =
+{
+      3450, 3670, 3721, 3751, 3782, 3821, 3876, 3941, 4034, 4125, 4200
+};
+
+unsigned int power_input_status(void)
+{
+    unsigned pwr = 0;
+    int sts = nwz_power_get_status();
+    if(sts & NWZ_POWER_STATUS_VBUS_DET)
+        pwr |= POWER_INPUT_USB_CHARGER;
+    if(sts & NWZ_POWER_STATUS_AC_DET)
+        pwr |= POWER_INPUT_MAIN_CHARGER;
+    return pwr;
+}
+
+int _battery_voltage(void)
+{
+    /* the raw voltage is unstable on some devices, so use the average provided
+     * by the driver */
+    return nwz_power_get_battery_voltage();
+}
+
+bool charging_state(void)
+{
+    return (nwz_power_get_status() & NWZ_POWER_STATUS_CHARGE_STATUS) ==
+        NWZ_POWER_STATUS_CHARGE_STATUS_CHARGING;
+}