From 2dc50471ca17eaeb24b45abce4c0f8944cd781d5 Mon Sep 17 00:00:00 2001
From: Frank Gevaerts <frank@gevaerts.be>
Date: Tue, 11 Aug 2009 19:30:19 +0000
Subject: [PATCH] Consolidate day of week calculation

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@22258 a1c6a512-1295-4272-9138-f99709370657
---
 apps/screens.c                  |  9 +--------
 firmware/common/timefuncs.c     |  7 +++++--
 firmware/include/timefuncs.h    |  2 +-
 firmware/usbstack/usb_storage.c | 22 ++++++++++++----------
 4 files changed, 19 insertions(+), 21 deletions(-)

diff --git a/apps/screens.c b/apps/screens.c
index 9f1596cb7a..4ec35f9f57 100644
--- a/apps/screens.c
+++ b/apps/screens.c
@@ -511,7 +511,6 @@ bool set_time_screen(const char* title, struct tm *tm)
     int button;
     unsigned int i, j, s;
     int cursorpos = 0;
-    unsigned int julianday;
     unsigned int realyear;
     unsigned int width;
     unsigned int min, max;
@@ -556,13 +555,7 @@ bool set_time_screen(const char* title, struct tm *tm)
             tm->tm_mday = daysinmonth[tm->tm_mon];
 
         /* calculate day of week */
-        julianday = tm->tm_mday;
-        for(i = 0; (int)i < tm->tm_mon; i++) {
-           julianday += daysinmonth[i];
-        }
-
-        tm->tm_wday = (realyear + julianday + (realyear - 1) / 4 -
-                       (realyear - 1) / 100 + (realyear - 1) / 400 + 7 - 1) % 7;
+        set_day_of_week(tm);
 
         /* put all the numbers we want from the tm struct into
            an easily printable buffer */
diff --git a/firmware/common/timefuncs.c b/firmware/common/timefuncs.c
index e59534eeba..774fba9ab0 100644
--- a/firmware/common/timefuncs.c
+++ b/firmware/common/timefuncs.c
@@ -194,12 +194,15 @@ time_t mktime(struct tm *t)
 }
 #endif
 
-int day_of_week(int m, int d, int y)
+void set_day_of_week(struct tm *tm)
 {
+        int y=tm->tm_year+1900;
+        int d=tm->tm_mday;
+        int m=tm->tm_mon;
         static const char mo[] = { 0, 3, 2, 5, 0, 3, 5, 1, 4, 6, 2, 4 };
 
         if(m == 0 || m == 1) y--;
-        return (d + mo[m] + y + y/4 - y/100 + y/400) % 7;
+        tm->tm_wday = (d + mo[m] + y + y/4 - y/100 + y/400) % 7;
 }
 
 void yearday_to_daymonth(int yd, int y, int *d, int *m)
diff --git a/firmware/include/timefuncs.h b/firmware/include/timefuncs.h
index 52d4608287..e9ef8075ac 100644
--- a/firmware/include/timefuncs.h
+++ b/firmware/include/timefuncs.h
@@ -29,7 +29,7 @@
 struct tm *get_time(void);
 int set_time(const struct tm *tm);
 bool valid_time(const struct tm *tm);
-int day_of_week(int m, int d, int y);
+void set_day_of_week(struct tm *tm);
 void yearday_to_daymonth(int yd, int y, int *d, int *m);
 #if CONFIG_RTC
 time_t mktime(struct tm *t);
diff --git a/firmware/usbstack/usb_storage.c b/firmware/usbstack/usb_storage.c
index 94f4f71dbb..a3664b074b 100644
--- a/firmware/usbstack/usb_storage.c
+++ b/firmware/usbstack/usb_storage.c
@@ -608,14 +608,13 @@ void usb_storage_transfer_complete(int ep,int dir,int status,int length)
             }
             break;
         case RECEIVING_TIME:
-            tm.tm_year=(tb.transfer_buffer[0]<<8)+tb.transfer_buffer[1];
+            tm.tm_year=(tb.transfer_buffer[0]<<8)+tb.transfer_buffer[1] - 1900;
             tm.tm_yday=(tb.transfer_buffer[2]<<8)+tb.transfer_buffer[3];
             tm.tm_hour=tb.transfer_buffer[5];
             tm.tm_min=tb.transfer_buffer[6];
             tm.tm_sec=tb.transfer_buffer[7];
-            yearday_to_daymonth(tm.tm_yday,tm.tm_year,&tm.tm_mday,&tm.tm_mon);
-            tm.tm_wday=day_of_week(tm.tm_mon,tm.tm_mday,tm.tm_year);
-            tm.tm_year -= 1900;
+            yearday_to_daymonth(tm.tm_yday,tm.tm_year + 1900,&tm.tm_mday,&tm.tm_mon);
+            set_day_of_week(&tm);
             set_time(&tm);
             send_csw(UMS_STATUS_GOOD);
             break;
@@ -1081,16 +1080,19 @@ static void handle_scsi(struct command_block_wrapper* cbw)
             break;
 
         case SCSI_WRITE_BUFFER:
-            if(cbw->command_block[1]==1
-            && cbw->command_block[2]==0
-            && cbw->command_block[3]==0x0c
+            if(cbw->command_block[1]==1 /* mode = vendor specific */
+            && cbw->command_block[2]==0 /* buffer id = 0 */
+
+            && cbw->command_block[3]==0x0c /* offset (3 bytes) */
             && cbw->command_block[4]==0
             && cbw->command_block[5]==0
-            && cbw->command_block[6]==0
+
+            /* Some versions of itunes set the parameter list length to 0.
+             * Technically it should be 0x0c, which is what libgpod sends */
+            && cbw->command_block[6]==0 /* parameter list (3 bytes) */
             && cbw->command_block[7]==0
-            /* Some versions of itunes set the next byte to 0. Technically
-             * it should be 0x0c */
             && (cbw->command_block[8]==0 || cbw->command_block[8]==0x0c)
+
             && cbw->command_block[9]==0)
             receive_time();
             break;