firmware/usb.c - rockbox - Gitiles

 /***************************************************************************
  *             __________               __   ___.
  *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
  *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
  *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
  *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
  *                     \/            \/     \/    \/            \/
  * $Id$
  *
  * Copyright (C) 2002 by Linus Nielsen Feltzing
  *
  * iPod driver based on code from the ipodlinux project - http://ipodlinux.org
  * Adapted for Rockbox in January 2006
  * Original file: podzilla/usb.c
  * Copyright (C) 2005 Adam Johnston
  *
  * 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 "config.h"
 #include "cpu.h"
 #include "kernel.h"
 #include "thread.h"
 #include "system.h"
 #include "debug.h"
 #include "storage.h"
 #include "disk.h"
 #include "panic.h"
 #include "lcd.h"
 #include "usb.h"
 #include "button.h"
 #include "string.h"
 #ifdef HAVE_USBSTACK
 #include "usb_core.h"
 #endif
 #include "logf.h"
 #include "screendump.h"

 /* Conditions under which we want the entire driver */
 #if !defined(BOOTLOADER) || (CONFIG_CPU == SH7034) || \
      (defined(HAVE_USBSTACK) && defined(HAVE_BOOTLOADER_USB_MODE)) || \
      (defined(HAVE_USBSTACK) && defined(IPOD_NANO2G)) || \
      (defined(HAVE_USBSTACK) && (defined(CREATIVE_ZVx))) || \
      (defined(HAVE_USBSTACK) && (defined(OLYMPUS_MROBE_500))) || \
      defined(CPU_TCC77X) || defined(CPU_TCC780X) || \
      (CONFIG_USBOTG == USBOTG_JZ4740) || \
      (CONFIG_USBOTG == USBOTG_JZ4760)
 /* TODO: condition should be reset to be only the original
    (defined(HAVE_USBSTACK) && defined(HAVE_BOOTLOADER_USB_MODE)) */
 #define USB_FULL_INIT
 #endif

 #ifdef HAVE_LCD_BITMAP
 bool do_screendump_instead_of_usb = false;
 #endif

 #if !defined(SIMULATOR) && !defined(USB_NONE)

 /* We assume that the USB cable is extracted */
 static int usb_state = USB_EXTRACTED;
 #if (CONFIG_STORAGE & STORAGE_MMC) && defined(USB_FULL_INIT) && !defined(HAVE_USBSTACK)
 static int usb_mmc_countdown = 0;
 #endif

 /* Make sure there's enough stack space for screendump */
 #ifdef USB_FULL_INIT
 static long usb_stack[(DEFAULT_STACK_SIZE + DUMP_BMP_LINESIZE)/sizeof(long)];
 static const char usb_thread_name[] = "usb";
 static unsigned int usb_thread_entry = 0;
 static bool usb_monitor_enabled = false;
 #endif /* USB_FULL_INIT */
 static struct event_queue usb_queue SHAREDBSS_ATTR;
 static bool exclusive_storage_access = false;
 #ifdef USB_ENABLE_HID
 static bool usb_hid = true;
 #endif

 #ifdef USB_FULL_INIT
 static bool usb_host_present = false;
 static int usb_num_acks_to_expect = 0;
 static long usb_last_broadcast_tick = 0;
 #ifdef HAVE_USB_POWER
 static bool usb_charging_only = false;
 #endif

 static int usb_release_exclusive_storage(void);

 #if defined(USB_FIREWIRE_HANDLING)
 static void try_reboot(void)
 {
 #ifdef HAVE_DISK_STORAGE
     storage_sleepnow(); /* Immediately spindown the disk. */
     sleep(HZ*2);
 #endif

 #ifdef IPOD_ARCH  /* The following code is based on ipodlinux */
 #if CONFIG_CPU == PP5020
     memcpy((void *)0x40017f00, "diskmode\0\0hotstuff\0\0\1", 21);
 #elif CONFIG_CPU == PP5022
     memcpy((void *)0x4001ff00, "diskmode\0\0hotstuff\0\0\1", 21);
 #endif /* CONFIG_CPU */
 #endif /* IPOD_ARCH */

 #ifdef IPOD_NANO2G
     memcpy((void *)0x0002bf00, "diskmodehotstuff\1\0\0\0", 20);
 #endif

     system_reboot(); /* Reboot */
 }
 #endif /* USB_FIRWIRE_HANDLING */

 /* Screen dump */
 #ifdef HAVE_LCD_BITMAP
 static inline bool usb_do_screendump(void)
 {
     if(do_screendump_instead_of_usb)
     {
         screen_dump();
 #ifdef HAVE_REMOTE_LCD
         remote_screen_dump();
 #endif /* HAVE_REMOTE_LCD */
         return true;
     }
     return false;
 }
 #endif /* HAVE_LCD_BITMAP */

 /* Power (charging-only) button */
 static inline void usb_detect_charging_only(bool detect)
 {
 #ifdef HAVE_USB_POWER
     if (detect)
         detect = button_status() & ~USBPOWER_BTN_IGNORE;

     usb_charging_only = detect;
 #endif
     (void)detect;
 }

 #ifdef USB_FIREWIRE_HANDLING
 static inline bool usb_reboot_button(void)
 {
 #ifdef HAVE_USB_POWER
     return (button_status() & ~USBPOWER_BTN_IGNORE);
 #else
     return false;
 #endif
 }
 #endif /* USB_FIREWIRE_HANDLING */


 /*--- Routines that differ depending upon the presence of a USB stack ---*/

 #ifdef HAVE_USBSTACK
 /* Enable / disable USB when the stack is enabled - otherwise a noop */
 static inline void usb_stack_enable(bool enable)
 {
     usb_enable(enable);
 }

 #ifdef HAVE_HOTSWAP
 static inline void usb_handle_hotswap(long id)
 {
     switch(id)
     {
     case SYS_HOTSWAP_INSERTED:
     case SYS_HOTSWAP_EXTRACTED:
         usb_core_hotswap_event(1, id == SYS_HOTSWAP_INSERTED);
         break;
     }
     /* Note: No MMC storage handling is needed with the stack atm. */
 }
 #endif /* HAVE_HOTSWAP */

 static inline bool usb_configure_drivers(int for_state)
 {
     switch(for_state)
     {
     case USB_POWERED:
 #ifdef USB_ENABLE_STORAGE
         usb_core_enable_driver(USB_DRIVER_MASS_STORAGE, false);
 #endif
 #ifdef USB_ENABLE_HID
 #ifdef USB_ENABLE_CHARGING_ONLY
         usb_core_enable_driver(USB_DRIVER_HID, false);
 #else
         usb_core_enable_driver(USB_DRIVER_HID, true);
 #endif /* USB_ENABLE_CHARGING_ONLY */
 #endif /* USB_ENABLE_HID */

 #ifdef USB_ENABLE_CHARGING_ONLY
         usb_core_enable_driver(USB_DRIVER_CHARGING_ONLY, true);
 #endif
         exclusive_storage_access = false;

         usb_attach(); /* Powered only: attach now. */
         break;
         /* USB_POWERED: */

     case USB_INSERTED:
 #ifdef USB_ENABLE_STORAGE
         usb_core_enable_driver(USB_DRIVER_MASS_STORAGE, true);
 #endif
 #ifdef USB_ENABLE_HID
         usb_core_enable_driver(USB_DRIVER_HID, usb_hid);
 #endif
 #ifdef USB_ENABLE_CHARGING_ONLY
         usb_core_enable_driver(USB_DRIVER_CHARGING_ONLY, false);
 #endif
         /* Check any drivers enabled at this point for exclusive storage
          * access requirements. */
         exclusive_storage_access = usb_core_any_exclusive_storage();

         if(exclusive_storage_access)
             return true;

         usb_attach(); /* Not exclusive: attach now. */
         break;
         /* USB_INSERTED: */

     case USB_EXTRACTED:
         if(exclusive_storage_access)
             usb_release_exclusive_storage();
         break;
         /* USB_EXTRACTED: */
     }

     return false;
 }

 static inline void usb_slave_mode(bool on)
 {
     int rc;

     if(on)
     {
         trigger_cpu_boost();
 #ifdef HAVE_PRIORITY_SCHEDULING
         thread_set_priority(thread_self(), PRIORITY_REALTIME);
 #endif
         disk_unmount_all();
         usb_attach();
     }
     else /* usb_state == USB_INSERTED (only!) */
     {
 #ifdef HAVE_PRIORITY_SCHEDULING
         thread_set_priority(thread_self(), PRIORITY_SYSTEM);
 #endif
         /* Entered exclusive mode */
         rc = disk_mount_all();
         if(rc <= 0) /* no partition */
             panicf("mount: %d",rc);

         cancel_cpu_boost();
     }
 }

 void usb_signal_transfer_completion(
     struct usb_transfer_completion_event_data* event_data)
 {
     queue_post(&usb_queue, USB_TRANSFER_COMPLETION, (intptr_t)event_data);
 }

 void usb_signal_notify(long id, intptr_t data)
 {
     queue_post(&usb_queue, id, data);
 }

 #else  /* !HAVE_USBSTACK */

 static inline void usb_stack_enable(bool enable)
 {
     (void)enable;
 }

 #ifdef HAVE_HOTSWAP
 static inline void usb_handle_hotswap(long id)
 {
 #if (CONFIG_STORAGE & STORAGE_MMC)
     switch(id)
     {
     case SYS_HOTSWAP_INSERTED:
     case SYS_HOTSWAP_EXTRACTED:
         if(usb_state == USB_INSERTED)
         {
             usb_enable(false);
             usb_mmc_countdown = HZ/2; /* re-enable after 0.5 sec */
         }
         break;
     case USB_REENABLE:
         if(usb_state == USB_INSERTED)
             usb_enable(true);  /* reenable only if still inserted */
         break;
     }
 #endif /* STORAGE_MMC */
     (void)id;
 }
 #endif /* HAVE_HOTSWAP */

 static inline bool usb_configure_drivers(int for_state)
 {
     switch(for_state)
     {
     case USB_POWERED:
         exclusive_storage_access = false;
         break;
     case USB_INSERTED:
         exclusive_storage_access = true;
         return true;
     case USB_EXTRACTED:
         if(exclusive_storage_access)
             usb_release_exclusive_storage();
         break;
     }

     return false;
 }

 static inline void usb_slave_mode(bool on)
 {
     int rc;

     if(on)
     {
         DEBUGF("Entering USB slave mode\n");
         disk_unmount_all();
         storage_soft_reset();
         storage_init();
         storage_enable(false);
         usb_enable(true);
         cpu_idle_mode(true);
     }
     else
     {
         DEBUGF("Leaving USB slave mode\n");

         cpu_idle_mode(false);

         /* Let the ISDx00 settle */
         sleep(HZ*1);

         usb_enable(false);

         rc = storage_init();
         if(rc)
             panicf("storage: %d",rc);

         sleep(HZ/10);
         rc = disk_mount_all();
         if(rc <= 0) /* no partition */
             panicf("mount: %d",rc);
     }
 }
 #endif /* HAVE_USBSTACK */

 static void usb_set_host_present(bool present)
 {
     if(usb_host_present == present)
         return;

     usb_host_present = present;

     if(!usb_host_present)
     {
         usb_configure_drivers(USB_EXTRACTED);
         return;
     }

 #ifdef HAVE_USB_POWER
     if (usb_charging_only)
     {
         /* Only charging is desired */
         usb_configure_drivers(USB_POWERED);
         return;
     }
 #endif

     if(!usb_configure_drivers(USB_INSERTED))
         return; /* Exclusive storage access not required */

     /* Tell all threads that they have to back off the storage.
        We subtract one for our own thread. Expect an ACK for every
        listener for each broadcast they received. If it has been too
        long, the user might have entered a screen that didn't ACK
        when inserting the cable, such as a debugging screen. In that
        case, reset the count or else USB would be locked out until
        rebooting because it most likely won't ever come. Simply
        resetting to the most recent broadcast count is racy. */
     if(TIME_AFTER(current_tick, usb_last_broadcast_tick + HZ*5))
     {
         usb_num_acks_to_expect = 0;
         usb_last_broadcast_tick = current_tick;
     }

     usb_num_acks_to_expect += queue_broadcast(SYS_USB_CONNECTED, 0) - 1;
     DEBUGF("usb: waiting for %d acks...\n", usb_num_acks_to_expect);
 }

 static bool usb_handle_connected_ack(void)
 {
     if(usb_num_acks_to_expect > 0 && --usb_num_acks_to_expect == 0)
     {
         DEBUGF("usb: all threads have acknowledged the connect.\n");
         if(usb_host_present)
         {
             usb_slave_mode(true);
             return true;
         }
     }
     else
     {
         DEBUGF("usb: got ack, %d to go...\n", usb_num_acks_to_expect);
     }

     return false;
 }

 /*--- General driver code ---*/
 static void NORETURN_ATTR usb_thread(void)
 {
     struct queue_event ev;

     while(1)
     {
         queue_wait(&usb_queue, &ev);

         switch(ev.id)
         {
         /*** Main USB thread duties ***/

 #ifdef HAVE_USBSTACK
         case USB_NOTIFY_SET_ADDR:
         case USB_NOTIFY_SET_CONFIG:
             if(usb_state <= USB_EXTRACTED)
                 break;
             usb_core_handle_notify(ev.id, ev.data);
             break;
         case USB_TRANSFER_COMPLETION:
             if(usb_state <= USB_EXTRACTED)
                 break;

 #ifdef USB_DETECT_BY_REQUEST
             usb_set_host_present(true);
 #endif

             usb_core_handle_transfer_completion(
                 (struct usb_transfer_completion_event_data*)ev.data);
             break;
 #endif /* HAVE_USBSTACK */

         case USB_INSERTED:
             if(usb_state != USB_EXTRACTED)
                 break;

 #ifdef HAVE_LCD_BITMAP
             if(usb_do_screendump())
             {
                 usb_state = USB_SCREENDUMP;
                 break;
             }
 #endif

             usb_state = USB_POWERED;
             usb_stack_enable(true);

             usb_detect_charging_only(true);

 #ifndef USB_DETECT_BY_REQUEST
             usb_set_host_present(true);
 #endif
             break;
             /* USB_INSERTED */

         case SYS_USB_CONNECTED_ACK:
             if(usb_handle_connected_ack())
                 usb_state = USB_INSERTED;
             break;
             /* SYS_USB_CONNECTED_ACK */

         case USB_EXTRACTED:
             if(usb_state == USB_EXTRACTED)
                 break;

             if(usb_state == USB_POWERED || usb_state == USB_INSERTED)
                 usb_stack_enable(false);

             /* Only disable the USB slave mode if we really have enabled
                it. Some expected acks may not have been received. */
             if(usb_state == USB_INSERTED)
                 usb_slave_mode(false);

             usb_state = USB_EXTRACTED;

             usb_detect_charging_only(false);
             usb_set_host_present(false);
             break;
             /* USB_EXTRACTED: */

         /*** Miscellaneous USB thread duties ***/

         /* HOTSWAP */
 #ifdef HAVE_HOTSWAP
         case SYS_HOTSWAP_INSERTED:
         case SYS_HOTSWAP_EXTRACTED:
 #if (CONFIG_STORAGE & STORAGE_MMC)
         case USB_REENABLE:
 #endif
             usb_handle_hotswap(ev.id);
             break;
 #endif

         /* FIREWIRE */
 #ifdef USB_FIREWIRE_HANDLING
         case USB_REQUEST_REBOOT:
             if(usb_reboot_button())
                 try_reboot();
             break;
 #endif

         /* CHARGING */
 #if defined(HAVE_USB_CHARGING_ENABLE) && defined(HAVE_USBSTACK)
         case USB_CHARGER_UPDATE:
             usb_charging_maxcurrent_change(usb_charging_maxcurrent());
             break;
 #endif

         /* CLOSE */
 #ifdef USB_DRIVER_CLOSE
         case USB_QUIT:
             thread_exit();
             break;
 #endif
         } /* switch */
     } /* while */
 }

 #if defined(HAVE_USB_CHARGING_ENABLE) && defined(HAVE_USBSTACK)
 void usb_charger_update(void)
 {
     queue_post(&usb_queue, USB_CHARGER_UPDATE, 0);
 }
 #endif

 #ifdef USB_STATUS_BY_EVENT
 void usb_status_event(int current_status)
 {
     /* Caller isn't expected to filter for changes in status.
      * current_status:
      *   USB_INSERTED, USB_EXTRACTED
      */
     if(usb_monitor_enabled)
     {
         int oldstatus = disable_irq_save(); /* Dual-use function */
         queue_remove_from_head(&usb_queue, current_status);
         queue_post(&usb_queue, current_status, 0);
         restore_irq(oldstatus);
     }
 }

 void usb_start_monitoring(void)
 {
     int oldstatus = disable_irq_save(); /* Sync to event */
     int status = usb_detect();

     usb_monitor_enabled = true;

     /* An event may have been missed because it was sent before monitoring
      * was enabled due to the connector already having been inserted before
      * before or during boot. */
     usb_status_event(status);

 #ifdef USB_FIREWIRE_HANDLING
     if(firewire_detect())
         usb_firewire_connect_event();
 #endif

     restore_irq(oldstatus);
 }

 #ifdef USB_FIREWIRE_HANDLING
 void usb_firewire_connect_event(void)
 {
     queue_post(&usb_queue, USB_REQUEST_REBOOT, 0);
 }
 #endif /* USB_FIREWIRE_HANDLING */

 #else /* !USB_STATUS_BY_EVENT */

 static void usb_tick(void)
 {
     #define NUM_POLL_READINGS (HZ/5)
     static int usb_countdown = -1;
     static int last_usb_status = USB_EXTRACTED;
 #ifdef USB_FIREWIRE_HANDLING
     static int firewire_countdown = -1;
     static int last_firewire_status = false;
 #endif

     if(usb_monitor_enabled)
     {
 #ifdef USB_FIREWIRE_HANDLING
         int current_firewire_status = firewire_detect();
         if(current_firewire_status != last_firewire_status)
         {
             last_firewire_status = current_firewire_status;
             firewire_countdown = NUM_POLL_READINGS;
         }
         else
         {
             /* Count down until it gets negative */
             if(firewire_countdown >= 0)
                 firewire_countdown--;

             /* Report to the thread if we have had 3 identical status
                readings in a row */
             if(firewire_countdown == 0)
             {
                 queue_post(&usb_queue, USB_REQUEST_REBOOT, 0);
             }
         }
 #endif /* USB_FIREWIRE_HANDLING */

         int current_status = usb_detect();

         /* Only report when the status has changed */
         if(current_status != last_usb_status)
         {
             last_usb_status = current_status;
             usb_countdown = NUM_POLL_READINGS;
         }
         else
         {
             /* Count down until it gets negative */
             if(usb_countdown >= 0)
                 usb_countdown--;

             /* Report to the thread if we have had 3 identical status
                readings in a row */
             if(usb_countdown == 0)
             {
                 queue_post(&usb_queue, current_status, 0);
             }
         }
     }
 #if (CONFIG_STORAGE & STORAGE_MMC)
     if(usb_mmc_countdown > 0)
     {
         usb_mmc_countdown--;
         if(usb_mmc_countdown == 0)
             queue_post(&usb_queue, USB_REENABLE, 0);
     }
 #endif
 }

 void usb_start_monitoring(void)
 {
     usb_monitor_enabled = true;
 }
 #endif /* USB_STATUS_BY_EVENT */
 #endif /* USB_FULL_INIT */

 void usb_acknowledge(long id)
 {
     queue_post(&usb_queue, id, 0);
 }

 void usb_init(void)
 {
     /* Do required hardware inits first. For software USB the driver has
      * to make sure this won't trigger a transfer completion before the
      * queue and thread are created. */
     usb_init_device();

 #ifdef USB_FULL_INIT
     usb_enable(false);

     queue_init(&usb_queue, true);

     usb_thread_entry = create_thread(usb_thread, usb_stack,
                        sizeof(usb_stack), 0, usb_thread_name
                        IF_PRIO(, PRIORITY_SYSTEM) IF_COP(, CPU));

 #ifndef USB_STATUS_BY_EVENT
     tick_add_task(usb_tick);
 #endif
 #endif /* USB_FULL_INIT */
 }

 void usb_wait_for_disconnect(struct event_queue *q)
 {
 #ifdef USB_FULL_INIT
     struct queue_event ev;

     /* Don't return until we get SYS_USB_DISCONNECTED */
     while(1)
     {
         queue_wait(q, &ev);
         if(ev.id == SYS_USB_DISCONNECTED)
             return;
     }
 #endif /* USB_FULL_INIT */
     (void)q;
 }

 int usb_wait_for_disconnect_w_tmo(struct event_queue *q, int ticks)
 {
 #ifdef USB_FULL_INIT
     struct queue_event ev;

     /* Don't return until we get SYS_USB_DISCONNECTED or SYS_TIMEOUT */
     while(1)
     {
         queue_wait_w_tmo(q, &ev, ticks);
         switch(ev.id)
         {
             case SYS_USB_DISCONNECTED:
                 return 0;
             case SYS_TIMEOUT:
                 return 1;
         }
     }
 #endif /* USB_FULL_INIT */
     (void)q; (void)ticks;
     return 0;
 }

 #ifdef USB_DRIVER_CLOSE
 void usb_close(void)
 {
     unsigned int thread = usb_thread_entry;
     usb_thread_entry = 0;

     if(thread == 0)
         return;

 #ifndef USB_STATUS_BY_EVENT
     tick_remove_task(usb_tick);
 #endif
     usb_monitor_enabled = false;
     queue_post(&usb_queue, USB_QUIT, 0);
     thread_wait(thread);
 }
 #endif /* USB_DRIVER_CLOSE */

 bool usb_inserted(void)
 {
     return usb_state == USB_INSERTED || usb_state == USB_POWERED;
 }

 #ifdef HAVE_USBSTACK
 bool usb_exclusive_storage(void)
 {
     /* Storage isn't actually exclusive until slave mode has been entered */
     return exclusive_storage_access && usb_state == USB_INSERTED;
 }
 #endif /* HAVE_USBSTACK */

 int usb_release_exclusive_storage(void)
 {
     int bccount;
     exclusive_storage_access = false;
     /* Tell all threads that we are back in business */
     bccount = queue_broadcast(SYS_USB_DISCONNECTED, 0) - 1;
     DEBUGF("USB extracted. Broadcast to %d threads...\n", bccount);
     return bccount;
 }

 #ifdef HAVE_USB_POWER
 bool usb_powered_only(void)
 {
     return usb_state == USB_POWERED;
 }
 #endif /* HAVE_USB_POWER */

 #ifdef USB_ENABLE_HID
 void usb_set_hid(bool enable)
 {
     usb_hid = enable;
     usb_core_enable_driver(USB_DRIVER_HID, usb_hid);
 }
 #endif /* USB_ENABLE_HID */

 #elif defined(USB_NONE)
 /* Dummy functions for USB_NONE  */

 bool usb_inserted(void)
 {
     return false;
 }

 void usb_acknowledge(long id)
 {
     (void)id;
 }

 void usb_init(void)
 {
 }

 void usb_start_monitoring(void)
 {
 }

 int usb_detect(void)
 {
     return USB_EXTRACTED;
 }

 void usb_wait_for_disconnect(struct event_queue *q)
 {
    (void)q;
 }
 #endif /* USB_NONE */
	/***************************************************************************
	* __________ __ ___.
	* Open \______ \ ____ ____ \| \| _\_ \|__ _______ ___
	* Source \| _// _ \_/ ___\\| \|/ /\| __ \ / _ \ \/ /
	* Jukebox \| \| ( <_> ) \___\| < \| \_\ ( <_> > < <
	* Firmware \|____\|_ /\____/ \___ >__\|_ \\|___ /\____/__/\_ \
	* \/ \/ \/ \/ \/
	* $Id$
	*
	* Copyright (C) 2002 by Linus Nielsen Feltzing
	*
	* iPod driver based on code from the ipodlinux project - http://ipodlinux.org
	* Adapted for Rockbox in January 2006
	* Original file: podzilla/usb.c
	* Copyright (C) 2005 Adam Johnston
	*
	* 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 "config.h"
	#include "cpu.h"
	#include "kernel.h"
	#include "thread.h"
	#include "system.h"
	#include "debug.h"
	#include "storage.h"
	#include "disk.h"
	#include "panic.h"
	#include "lcd.h"
	#include "usb.h"
	#include "button.h"
	#include "string.h"
	#ifdef HAVE_USBSTACK
	#include "usb_core.h"
	#endif
	#include "logf.h"
	#include "screendump.h"

	/* Conditions under which we want the entire driver */
	#if !defined(BOOTLOADER) \|\| (CONFIG_CPU == SH7034) \|\| \
	(defined(HAVE_USBSTACK) && defined(HAVE_BOOTLOADER_USB_MODE)) \|\| \
	(defined(HAVE_USBSTACK) && defined(IPOD_NANO2G)) \|\| \
	(defined(HAVE_USBSTACK) && (defined(CREATIVE_ZVx))) \|\| \
	(defined(HAVE_USBSTACK) && (defined(OLYMPUS_MROBE_500))) \|\| \
	defined(CPU_TCC77X) \|\| defined(CPU_TCC780X) \|\| \
	(CONFIG_USBOTG == USBOTG_JZ4740) \|\| \
	(CONFIG_USBOTG == USBOTG_JZ4760)
	/* TODO: condition should be reset to be only the original
	(defined(HAVE_USBSTACK) && defined(HAVE_BOOTLOADER_USB_MODE)) */
	#define USB_FULL_INIT
	#endif

	#ifdef HAVE_LCD_BITMAP
	bool do_screendump_instead_of_usb = false;
	#endif

	#if !defined(SIMULATOR) && !defined(USB_NONE)

	/* We assume that the USB cable is extracted */
	static int usb_state = USB_EXTRACTED;
	#if (CONFIG_STORAGE & STORAGE_MMC) && defined(USB_FULL_INIT) && !defined(HAVE_USBSTACK)
	static int usb_mmc_countdown = 0;
	#endif

	/* Make sure there's enough stack space for screendump */
	#ifdef USB_FULL_INIT
	static long usb_stack[(DEFAULT_STACK_SIZE + DUMP_BMP_LINESIZE)/sizeof(long)];
	static const char usb_thread_name[] = "usb";
	static unsigned int usb_thread_entry = 0;
	static bool usb_monitor_enabled = false;
	#endif /* USB_FULL_INIT */
	static struct event_queue usb_queue SHAREDBSS_ATTR;
	static bool exclusive_storage_access = false;
	#ifdef USB_ENABLE_HID
	static bool usb_hid = true;
	#endif

	#ifdef USB_FULL_INIT
	static bool usb_host_present = false;
	static int usb_num_acks_to_expect = 0;
	static long usb_last_broadcast_tick = 0;
	#ifdef HAVE_USB_POWER
	static bool usb_charging_only = false;
	#endif

	static int usb_release_exclusive_storage(void);

	#if defined(USB_FIREWIRE_HANDLING)
	static void try_reboot(void)
	{
	#ifdef HAVE_DISK_STORAGE
	storage_sleepnow(); /* Immediately spindown the disk. */
	sleep(HZ*2);
	#endif

	#ifdef IPOD_ARCH /* The following code is based on ipodlinux */
	#if CONFIG_CPU == PP5020
	memcpy((void *)0x40017f00, "diskmode\0\0hotstuff\0\0\1", 21);
	#elif CONFIG_CPU == PP5022
	memcpy((void *)0x4001ff00, "diskmode\0\0hotstuff\0\0\1", 21);
	#endif /* CONFIG_CPU */
	#endif /* IPOD_ARCH */

	#ifdef IPOD_NANO2G
	memcpy((void *)0x0002bf00, "diskmodehotstuff\1\0\0\0", 20);
	#endif

	system_reboot(); /* Reboot */
	}
	#endif /* USB_FIRWIRE_HANDLING */

	/* Screen dump */
	#ifdef HAVE_LCD_BITMAP
	static inline bool usb_do_screendump(void)
	{
	if(do_screendump_instead_of_usb)
	{
	screen_dump();
	#ifdef HAVE_REMOTE_LCD
	remote_screen_dump();
	#endif /* HAVE_REMOTE_LCD */
	return true;
	}
	return false;
	}
	#endif /* HAVE_LCD_BITMAP */

	/* Power (charging-only) button */
	static inline void usb_detect_charging_only(bool detect)
	{
	#ifdef HAVE_USB_POWER
	if (detect)
	detect = button_status() & ~USBPOWER_BTN_IGNORE;

	usb_charging_only = detect;
	#endif
	(void)detect;
	}

	#ifdef USB_FIREWIRE_HANDLING
	static inline bool usb_reboot_button(void)
	{
	#ifdef HAVE_USB_POWER
	return (button_status() & ~USBPOWER_BTN_IGNORE);
	#else
	return false;
	#endif
	}
	#endif /* USB_FIREWIRE_HANDLING */


	/--- Routines that differ depending upon the presence of a USB stack ---/

	#ifdef HAVE_USBSTACK
	/* Enable / disable USB when the stack is enabled - otherwise a noop */
	static inline void usb_stack_enable(bool enable)
	{
	usb_enable(enable);
	}

	#ifdef HAVE_HOTSWAP
	static inline void usb_handle_hotswap(long id)
	{
	switch(id)
	{
	case SYS_HOTSWAP_INSERTED:
	case SYS_HOTSWAP_EXTRACTED:
	usb_core_hotswap_event(1, id == SYS_HOTSWAP_INSERTED);
	break;
	}
	/* Note: No MMC storage handling is needed with the stack atm. */
	}
	#endif /* HAVE_HOTSWAP */

	static inline bool usb_configure_drivers(int for_state)
	{
	switch(for_state)
	{
	case USB_POWERED:
	#ifdef USB_ENABLE_STORAGE
	usb_core_enable_driver(USB_DRIVER_MASS_STORAGE, false);
	#endif
	#ifdef USB_ENABLE_HID
	#ifdef USB_ENABLE_CHARGING_ONLY
	usb_core_enable_driver(USB_DRIVER_HID, false);
	#else
	usb_core_enable_driver(USB_DRIVER_HID, true);
	#endif /* USB_ENABLE_CHARGING_ONLY */
	#endif /* USB_ENABLE_HID */

	#ifdef USB_ENABLE_CHARGING_ONLY
	usb_core_enable_driver(USB_DRIVER_CHARGING_ONLY, true);
	#endif
	exclusive_storage_access = false;

	usb_attach(); /* Powered only: attach now. */
	break;
	/* USB_POWERED: */

	case USB_INSERTED:
	#ifdef USB_ENABLE_STORAGE
	usb_core_enable_driver(USB_DRIVER_MASS_STORAGE, true);
	#endif
	#ifdef USB_ENABLE_HID
	usb_core_enable_driver(USB_DRIVER_HID, usb_hid);
	#endif
	#ifdef USB_ENABLE_CHARGING_ONLY
	usb_core_enable_driver(USB_DRIVER_CHARGING_ONLY, false);
	#endif
	/* Check any drivers enabled at this point for exclusive storage
	* access requirements. */
	exclusive_storage_access = usb_core_any_exclusive_storage();

	if(exclusive_storage_access)
	return true;

	usb_attach(); /* Not exclusive: attach now. */
	break;
	/* USB_INSERTED: */

	case USB_EXTRACTED:
	if(exclusive_storage_access)
	usb_release_exclusive_storage();
	break;
	/* USB_EXTRACTED: */
	}

	return false;
	}

	static inline void usb_slave_mode(bool on)
	{
	int rc;

	if(on)
	{
	trigger_cpu_boost();
	#ifdef HAVE_PRIORITY_SCHEDULING
	thread_set_priority(thread_self(), PRIORITY_REALTIME);
	#endif
	disk_unmount_all();
	usb_attach();
	}
	else /* usb_state == USB_INSERTED (only!) */
	{
	#ifdef HAVE_PRIORITY_SCHEDULING
	thread_set_priority(thread_self(), PRIORITY_SYSTEM);
	#endif
	/* Entered exclusive mode */
	rc = disk_mount_all();
	if(rc <= 0) /* no partition */
	panicf("mount: %d",rc);

	cancel_cpu_boost();
	}
	}

	void usb_signal_transfer_completion(
	struct usb_transfer_completion_event_data* event_data)
	{
	queue_post(&usb_queue, USB_TRANSFER_COMPLETION, (intptr_t)event_data);
	}

	void usb_signal_notify(long id, intptr_t data)
	{
	queue_post(&usb_queue, id, data);
	}

	#else /* !HAVE_USBSTACK */

	static inline void usb_stack_enable(bool enable)
	{
	(void)enable;
	}

	#ifdef HAVE_HOTSWAP
	static inline void usb_handle_hotswap(long id)
	{
	#if (CONFIG_STORAGE & STORAGE_MMC)
	switch(id)
	{
	case SYS_HOTSWAP_INSERTED:
	case SYS_HOTSWAP_EXTRACTED:
	if(usb_state == USB_INSERTED)
	{
	usb_enable(false);
	usb_mmc_countdown = HZ/2; /* re-enable after 0.5 sec */
	}
	break;
	case USB_REENABLE:
	if(usb_state == USB_INSERTED)
	usb_enable(true); /* reenable only if still inserted */
	break;
	}
	#endif /* STORAGE_MMC */
	(void)id;
	}
	#endif /* HAVE_HOTSWAP */

	static inline bool usb_configure_drivers(int for_state)
	{
	switch(for_state)
	{
	case USB_POWERED:
	exclusive_storage_access = false;
	break;
	case USB_INSERTED:
	exclusive_storage_access = true;
	return true;
	case USB_EXTRACTED:
	if(exclusive_storage_access)
	usb_release_exclusive_storage();
	break;
	}

	return false;
	}

	static inline void usb_slave_mode(bool on)
	{
	int rc;

	if(on)
	{
	DEBUGF("Entering USB slave mode\n");
	disk_unmount_all();
	storage_soft_reset();
	storage_init();
	storage_enable(false);
	usb_enable(true);
	cpu_idle_mode(true);
	}
	else
	{
	DEBUGF("Leaving USB slave mode\n");

	cpu_idle_mode(false);

	/* Let the ISDx00 settle */
	sleep(HZ*1);

	usb_enable(false);

	rc = storage_init();
	if(rc)
	panicf("storage: %d",rc);

	sleep(HZ/10);
	rc = disk_mount_all();
	if(rc <= 0) /* no partition */
	panicf("mount: %d",rc);
	}
	}
	#endif /* HAVE_USBSTACK */

	static void usb_set_host_present(bool present)
	{
	if(usb_host_present == present)
	return;

	usb_host_present = present;

	if(!usb_host_present)
	{
	usb_configure_drivers(USB_EXTRACTED);
	return;
	}

	#ifdef HAVE_USB_POWER
	if (usb_charging_only)
	{
	/* Only charging is desired */
	usb_configure_drivers(USB_POWERED);
	return;
	}
	#endif

	if(!usb_configure_drivers(USB_INSERTED))
	return; /* Exclusive storage access not required */

	/* Tell all threads that they have to back off the storage.
	We subtract one for our own thread. Expect an ACK for every
	listener for each broadcast they received. If it has been too
	long, the user might have entered a screen that didn't ACK
	when inserting the cable, such as a debugging screen. In that
	case, reset the count or else USB would be locked out until
	rebooting because it most likely won't ever come. Simply
	resetting to the most recent broadcast count is racy. */
	if(TIME_AFTER(current_tick, usb_last_broadcast_tick + HZ*5))
	{
	usb_num_acks_to_expect = 0;
	usb_last_broadcast_tick = current_tick;
	}

	usb_num_acks_to_expect += queue_broadcast(SYS_USB_CONNECTED, 0) - 1;
	DEBUGF("usb: waiting for %d acks...\n", usb_num_acks_to_expect);
	}

	static bool usb_handle_connected_ack(void)
	{
	if(usb_num_acks_to_expect > 0 && --usb_num_acks_to_expect == 0)
	{
	DEBUGF("usb: all threads have acknowledged the connect.\n");
	if(usb_host_present)
	{
	usb_slave_mode(true);
	return true;
	}
	}
	else
	{
	DEBUGF("usb: got ack, %d to go...\n", usb_num_acks_to_expect);
	}

	return false;
	}

	/--- General driver code ---/
	static void NORETURN_ATTR usb_thread(void)
	{
	struct queue_event ev;

	while(1)
	{
	queue_wait(&usb_queue, &ev);

	switch(ev.id)
	{
	/* Main USB thread duties */

	#ifdef HAVE_USBSTACK
	case USB_NOTIFY_SET_ADDR:
	case USB_NOTIFY_SET_CONFIG:
	if(usb_state <= USB_EXTRACTED)
	break;
	usb_core_handle_notify(ev.id, ev.data);
	break;
	case USB_TRANSFER_COMPLETION:
	if(usb_state <= USB_EXTRACTED)
	break;

	#ifdef USB_DETECT_BY_REQUEST
	usb_set_host_present(true);
	#endif

	usb_core_handle_transfer_completion(
	(struct usb_transfer_completion_event_data*)ev.data);
	break;
	#endif /* HAVE_USBSTACK */

	case USB_INSERTED:
	if(usb_state != USB_EXTRACTED)
	break;

	#ifdef HAVE_LCD_BITMAP
	if(usb_do_screendump())
	{
	usb_state = USB_SCREENDUMP;
	break;
	}
	#endif

	usb_state = USB_POWERED;
	usb_stack_enable(true);

	usb_detect_charging_only(true);

	#ifndef USB_DETECT_BY_REQUEST
	usb_set_host_present(true);
	#endif
	break;
	/* USB_INSERTED */

	case SYS_USB_CONNECTED_ACK:
	if(usb_handle_connected_ack())
	usb_state = USB_INSERTED;
	break;
	/* SYS_USB_CONNECTED_ACK */

	case USB_EXTRACTED:
	if(usb_state == USB_EXTRACTED)
	break;

	if(usb_state == USB_POWERED \|\| usb_state == USB_INSERTED)
	usb_stack_enable(false);

	/* Only disable the USB slave mode if we really have enabled
	it. Some expected acks may not have been received. */
	if(usb_state == USB_INSERTED)
	usb_slave_mode(false);

	usb_state = USB_EXTRACTED;

	usb_detect_charging_only(false);
	usb_set_host_present(false);
	break;
	/* USB_EXTRACTED: */

	/* Miscellaneous USB thread duties */

	/* HOTSWAP */
	#ifdef HAVE_HOTSWAP
	case SYS_HOTSWAP_INSERTED:
	case SYS_HOTSWAP_EXTRACTED:
	#if (CONFIG_STORAGE & STORAGE_MMC)
	case USB_REENABLE:
	#endif
	usb_handle_hotswap(ev.id);
	break;
	#endif

	/* FIREWIRE */
	#ifdef USB_FIREWIRE_HANDLING
	case USB_REQUEST_REBOOT:
	if(usb_reboot_button())
	try_reboot();
	break;
	#endif

	/* CHARGING */
	#if defined(HAVE_USB_CHARGING_ENABLE) && defined(HAVE_USBSTACK)
	case USB_CHARGER_UPDATE:
	usb_charging_maxcurrent_change(usb_charging_maxcurrent());
	break;
	#endif

	/* CLOSE */
	#ifdef USB_DRIVER_CLOSE
	case USB_QUIT:
	thread_exit();
	break;
	#endif
	} /* switch */
	} /* while */
	}

	#if defined(HAVE_USB_CHARGING_ENABLE) && defined(HAVE_USBSTACK)
	void usb_charger_update(void)
	{
	queue_post(&usb_queue, USB_CHARGER_UPDATE, 0);
	}
	#endif

	#ifdef USB_STATUS_BY_EVENT
	void usb_status_event(int current_status)
	{
	/* Caller isn't expected to filter for changes in status.
	* current_status:
	* USB_INSERTED, USB_EXTRACTED
	*/
	if(usb_monitor_enabled)
	{
	int oldstatus = disable_irq_save(); /* Dual-use function */
	queue_remove_from_head(&usb_queue, current_status);
	queue_post(&usb_queue, current_status, 0);
	restore_irq(oldstatus);
	}
	}

	void usb_start_monitoring(void)
	{
	int oldstatus = disable_irq_save(); /* Sync to event */
	int status = usb_detect();

	usb_monitor_enabled = true;

	/* An event may have been missed because it was sent before monitoring
	* was enabled due to the connector already having been inserted before
	* before or during boot. */
	usb_status_event(status);

	#ifdef USB_FIREWIRE_HANDLING
	if(firewire_detect())
	usb_firewire_connect_event();
	#endif

	restore_irq(oldstatus);
	}

	#ifdef USB_FIREWIRE_HANDLING
	void usb_firewire_connect_event(void)
	{
	queue_post(&usb_queue, USB_REQUEST_REBOOT, 0);
	}
	#endif /* USB_FIREWIRE_HANDLING */

	#else /* !USB_STATUS_BY_EVENT */

	static void usb_tick(void)
	{
	#define NUM_POLL_READINGS (HZ/5)
	static int usb_countdown = -1;
	static int last_usb_status = USB_EXTRACTED;
	#ifdef USB_FIREWIRE_HANDLING
	static int firewire_countdown = -1;
	static int last_firewire_status = false;
	#endif

	if(usb_monitor_enabled)
	{
	#ifdef USB_FIREWIRE_HANDLING
	int current_firewire_status = firewire_detect();
	if(current_firewire_status != last_firewire_status)
	{
	last_firewire_status = current_firewire_status;
	firewire_countdown = NUM_POLL_READINGS;
	}
	else
	{
	/* Count down until it gets negative */
	if(firewire_countdown >= 0)
	firewire_countdown--;

	/* Report to the thread if we have had 3 identical status
	readings in a row */
	if(firewire_countdown == 0)
	{
	queue_post(&usb_queue, USB_REQUEST_REBOOT, 0);
	}
	}
	#endif /* USB_FIREWIRE_HANDLING */

	int current_status = usb_detect();

	/* Only report when the status has changed */
	if(current_status != last_usb_status)
	{
	last_usb_status = current_status;
	usb_countdown = NUM_POLL_READINGS;
	}
	else
	{
	/* Count down until it gets negative */
	if(usb_countdown >= 0)
	usb_countdown--;

	/* Report to the thread if we have had 3 identical status
	readings in a row */
	if(usb_countdown == 0)
	{
	queue_post(&usb_queue, current_status, 0);
	}
	}
	}
	#if (CONFIG_STORAGE & STORAGE_MMC)
	if(usb_mmc_countdown > 0)
	{
	usb_mmc_countdown--;
	if(usb_mmc_countdown == 0)
	queue_post(&usb_queue, USB_REENABLE, 0);
	}
	#endif
	}

	void usb_start_monitoring(void)
	{
	usb_monitor_enabled = true;
	}
	#endif /* USB_STATUS_BY_EVENT */
	#endif /* USB_FULL_INIT */

	void usb_acknowledge(long id)
	{
	queue_post(&usb_queue, id, 0);
	}

	void usb_init(void)
	{
	/* Do required hardware inits first. For software USB the driver has
	* to make sure this won't trigger a transfer completion before the
	* queue and thread are created. */
	usb_init_device();

	#ifdef USB_FULL_INIT
	usb_enable(false);

	queue_init(&usb_queue, true);

	usb_thread_entry = create_thread(usb_thread, usb_stack,
	sizeof(usb_stack), 0, usb_thread_name
	IF_PRIO(, PRIORITY_SYSTEM) IF_COP(, CPU));

	#ifndef USB_STATUS_BY_EVENT
	tick_add_task(usb_tick);
	#endif
	#endif /* USB_FULL_INIT */
	}

	void usb_wait_for_disconnect(struct event_queue *q)
	{
	#ifdef USB_FULL_INIT
	struct queue_event ev;

	/* Don't return until we get SYS_USB_DISCONNECTED */
	while(1)
	{
	queue_wait(q, &ev);
	if(ev.id == SYS_USB_DISCONNECTED)
	return;
	}
	#endif /* USB_FULL_INIT */
	(void)q;
	}

	int usb_wait_for_disconnect_w_tmo(struct event_queue *q, int ticks)
	{
	#ifdef USB_FULL_INIT
	struct queue_event ev;

	/* Don't return until we get SYS_USB_DISCONNECTED or SYS_TIMEOUT */
	while(1)
	{
	queue_wait_w_tmo(q, &ev, ticks);
	switch(ev.id)
	{
	case SYS_USB_DISCONNECTED:
	return 0;
	case SYS_TIMEOUT:
	return 1;
	}
	}
	#endif /* USB_FULL_INIT */
	(void)q; (void)ticks;
	return 0;
	}

	#ifdef USB_DRIVER_CLOSE
	void usb_close(void)
	{
	unsigned int thread = usb_thread_entry;
	usb_thread_entry = 0;

	if(thread == 0)
	return;

	#ifndef USB_STATUS_BY_EVENT
	tick_remove_task(usb_tick);
	#endif
	usb_monitor_enabled = false;
	queue_post(&usb_queue, USB_QUIT, 0);
	thread_wait(thread);
	}
	#endif /* USB_DRIVER_CLOSE */

	bool usb_inserted(void)
	{
	return usb_state == USB_INSERTED \|\| usb_state == USB_POWERED;
	}

	#ifdef HAVE_USBSTACK
	bool usb_exclusive_storage(void)
	{
	/* Storage isn't actually exclusive until slave mode has been entered */
	return exclusive_storage_access && usb_state == USB_INSERTED;
	}
	#endif /* HAVE_USBSTACK */

	int usb_release_exclusive_storage(void)
	{
	int bccount;
	exclusive_storage_access = false;
	/* Tell all threads that we are back in business */
	bccount = queue_broadcast(SYS_USB_DISCONNECTED, 0) - 1;
	DEBUGF("USB extracted. Broadcast to %d threads...\n", bccount);
	return bccount;
	}

	#ifdef HAVE_USB_POWER
	bool usb_powered_only(void)
	{
	return usb_state == USB_POWERED;
	}
	#endif /* HAVE_USB_POWER */

	#ifdef USB_ENABLE_HID
	void usb_set_hid(bool enable)
	{
	usb_hid = enable;
	usb_core_enable_driver(USB_DRIVER_HID, usb_hid);
	}
	#endif /* USB_ENABLE_HID */

	#elif defined(USB_NONE)
	/* Dummy functions for USB_NONE */

	bool usb_inserted(void)
	{
	return false;
	}

	void usb_acknowledge(long id)
	{
	(void)id;
	}

	void usb_init(void)
	{
	}

	void usb_start_monitoring(void)
	{
	}

	int usb_detect(void)
	{
	return USB_EXTRACTED;
	}

	void usb_wait_for_disconnect(struct event_queue *q)
	{
	(void)q;
	}
	#endif /* USB_NONE */