LCD flip (upside down) and a high-performance blit function

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@4143 a1c6a512-1295-4272-9138-f99709370657

2 files changed, 154 insertions, 7 deletions

diff --git a/firmware/drivers/lcd-recorder.c b/firmware/drivers/lcd-recorder.c
index a409c9fc63..0a95e82c3d 100644
--- a/firmware/drivers/lcd-recorder.c
+++ b/firmware/drivers/lcd-recorder.c
@@ -103,10 +103,8 @@ static struct scrollinfo scroll[SCROLLABLE_LINES];
 static int xmargin = 0;
 static int ymargin = 0;
 static int curfont = FONT_SYSFIXED;
+static int xoffset = 0; /* needed for flip */
 
-#ifndef SIMULATOR
-static
-#endif
 unsigned char lcd_framebuffer[LCD_WIDTH][LCD_HEIGHT/8];
 
 /* All zeros and ones bitmaps for area filling */
@@ -163,6 +161,25 @@ void lcd_init (void)
                   sizeof(scroll_stack), scroll_name);
 }
 
+
+/* Performance function that works with an external buffer
+   note that y and height are in 8-pixel units! */
+void lcd_blit (unsigned char* p_data, int x, int y, int width, int height, int stride) __attribute__ ((section (".icode")));
+void lcd_blit (unsigned char* p_data, int x, int y, int width, int height, int stride)
+{
+    /* Copy display bitmap to hardware */
+    while (height--)
+    {
+        lcd_write (true, LCD_CNTL_PAGE | (y++ & 0xf));
+        lcd_write (true, LCD_CNTL_HIGHCOL | (((x+xoffset)>>4) & 0xf));
+        lcd_write (true, LCD_CNTL_LOWCOL | ((x+xoffset) & 0xf));
+
+        lcd_write_data(p_data, width);
+        p_data += stride;
+    } 
+}
+
+
 /*
  * Update the display.
  * This must be called after all other LCD functions that change the display.
@@ -176,8 +193,8 @@ void lcd_update (void)
     for (y = 0; y < LCD_HEIGHT/8; y++)
     {
         lcd_write (true, LCD_CNTL_PAGE | (y & 0xf));
-        lcd_write (true, LCD_CNTL_HIGHCOL);
-        lcd_write (true, LCD_CNTL_LOWCOL);
+        lcd_write (true, LCD_CNTL_HIGHCOL | ((xoffset>>4) & 0xf));
+        lcd_write (true, LCD_CNTL_LOWCOL | (xoffset & 0xf));
 
         for (x = 0; x < LCD_WIDTH; x++)
             lcd_write (false, lcd_framebuffer[x][y]);
@@ -210,8 +227,8 @@ void lcd_update_rect (int x_start, int y,
     for (; y <= ymax; y++)
     {
         lcd_write (true, LCD_CNTL_PAGE | (y & 0xf));
-        lcd_write (true, LCD_CNTL_HIGHCOL | ((x_start>>4) & 0xf));
-        lcd_write (true, LCD_CNTL_LOWCOL | (x_start & 0xf));
+        lcd_write (true, LCD_CNTL_HIGHCOL | (((x_start+xoffset)>>4) & 0xf));
+        lcd_write (true, LCD_CNTL_LOWCOL | ((x_start+xoffset) & 0xf));
 
         for (x = x_start; x < xmax; x++)
             lcd_write (false, lcd_framebuffer[x][y]);
@@ -232,6 +249,23 @@ void lcd_set_invert_display(bool yesno)
         lcd_write(true, LCD_SET_NORMAL_DISPLAY);
 }
 
+/* turn the display upside down (call lcd_update() afterwards) */
+void lcd_set_flip(bool yesno)
+{
+    if (yesno) 
+    {
+        lcd_write(true, LCD_SET_SEGMENT_REMAP);
+        lcd_write(true, LCD_SET_COM_OUTPUT_SCAN_DIRECTION);
+        xoffset = 132 - LCD_WIDTH; /* 132 colums minus the 112 we have */
+    }
+    else 
+    {
+        lcd_write(true, LCD_SET_SEGMENT_REMAP | 0x01);
+        lcd_write(true, LCD_SET_COM_OUTPUT_SCAN_DIRECTION | 0x08);
+        xoffset = 0;
+    }
+}
+
 /**
  * Rolls up the lcd display by the specified amount of lines.
  * Lines that are rolled out over the top of the screen are
diff --git a/firmware/drivers/lcd.c b/firmware/drivers/lcd.c
index 3f6acee301..aaa93b3385 100644
--- a/firmware/drivers/lcd.c
+++ b/firmware/drivers/lcd.c
@@ -173,3 +173,116 @@ void lcd_write(bool command, int byte)
          : /* %0 */ "I"(LCD_CS|LCD_DS|LCD_SD|LCD_SC),
            /* %1 */ "z"(LCDR));
 }
+
+
+/* A high performance function to write data to the display, 
+   one or multiple bytes.
+   Ultimately, all calls to lcd_write(false, xxx) should be substituted by 
+   this, it will be most efficient if the LCD buffer is tilted to have the
+   X row as consecutive bytes, so we can write a whole row */
+/* FixMe: somehow the red LED is affected by this, although I don't touch
+   any other bit. Therefore not used yet, except for lcd_blit() */
+void lcd_write_data(unsigned char* p_bytes, int count) __attribute__ ((section (".icode")));
+void lcd_write_data(unsigned char* p_bytes, int count)
+{
+    do
+    {
+        unsigned byte;
+        unsigned sda1;     /* precalculated SC=low,SD=1 */
+        unsigned clk0sda0; /* precalculated SC and SD low */
+
+        cli(); /* make port modifications atomic */
+
+        /* precalculate the values for later bit toggling, init data write */
+        asm (
+            "mov.b  @%2,%0\n" /* sda1 = PBDRL */
+            "or     %4,%0\n"  /* sda1 |= LCD_DS | LCD_SD     DS and SD high, */
+            "and    %3,%0\n"  /* sda1 &= ~(LCD_CS | LCD_SC)  CS and SC low   */
+            "mov    %0,%1\n"  /* sda1 -> clk0sda0 */
+            "and    %5,%1\n"  /* clk0sda0 &= ~LCD_SD  both low */
+            "mov.b  %1,@%2\n" /* PBDRL = clk0sda0 */
+            : // outputs
+            /* %0 */ "=r"(sda1),
+            /* %1 */ "=r"(clk0sda0)
+            : // inputs
+            /* %2 */ "r"(LCDR),
+            /* %3 */ "r"(~(LCD_CS | LCD_SC)),
+            /* %4 */ "r"(LCD_DS | LCD_SD),
+            /* %5 */ "r"(~LCD_SD)
+        );
+        
+        byte = *p_bytes++ << 24; /* fetch to MSB position */
+
+        /* unrolled loop to serialize the byte */
+        asm (
+            "mov    %4,r0\n" /* we need &PBDRL in r0 for "or.b x,@(r0,gbr)" */
+            
+            "shll   %0\n" /* shift the MSB into carry */
+            "bf     1f\n"
+            "mov.b  %1,@%4\n" /* if it was a "1": set SD high, SC low still */
+            "1:       \n"
+            "or.b   %2, @(r0,gbr)\n" /* rise SC (independent of SD level) */
+            "shll   %0\n" /* shift for next round, now for longer hold time */
+            "mov.b  %3,@%4\n" /* SC and SD low again */
+
+            "bf     1f\n"
+            "mov.b  %1,@%4\n"
+            "1:       \n"
+            "or.b   %2, @(r0,gbr)\n"
+            "shll   %0\n"
+            "mov.b  %3,@%4\n"
+            
+            "bf     1f\n"
+            "mov.b  %1,@%4\n"
+            "1:       \n"
+            "or.b   %2, @(r0,gbr)\n"
+            "shll   %0\n"
+            "mov.b  %3,@%4\n"
+            
+            "bf     1f\n"
+            "mov.b  %1,@%4\n"
+            "1:       \n"
+            "or.b   %2, @(r0,gbr)\n"
+            "shll   %0\n"
+            "mov.b  %3,@%4\n"
+            
+            "bf     1f\n"
+            "mov.b  %1,@%4\n"
+            "1:       \n"
+            "or.b   %2, @(r0,gbr)\n"
+            "shll   %0\n"
+            "mov.b  %3,@%4\n"
+            
+            "bf     1f\n"
+            "mov.b  %1,@%4\n"
+            "1:       \n"
+            "or.b   %2, @(r0,gbr)\n"
+            "shll   %0\n"
+            "mov.b  %3,@%4\n"
+            
+            "bf     1f\n"
+            "mov.b  %1,@%4\n"
+            "1:       \n"
+            "or.b   %2, @(r0,gbr)\n"
+            "shll   %0\n"
+            "mov.b  %3,@%4\n"
+            
+            "bf     1f\n"
+            "mov.b  %1,@%4\n"
+            "1:       \n"
+            "or.b   %2, @(r0,gbr)\n"
+
+            "or.b   %5, @(r0,gbr)\n" /* restore port */
+            :
+            : /* %0 */ "r"(byte),
+            /* %1 */ "r"(sda1),
+            /* %2 */ "I"(LCD_SC),
+            /* %3 */ "r"(clk0sda0),
+            /* %4 */ "r"(LCDR),
+            /* %5 */ "I"(LCD_CS|LCD_DS|LCD_SD|LCD_SC)
+        );
+
+        sti();
+
+    } while (--count); /* tail loop is faster */
+}