Sansa Clip: grey lib support (not calibrated yet)

Declare HAVE_LCD_INVERT
Put the framebuffer into IRAM

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@19249 a1c6a512-1295-4272-9138-f99709370657

firmware/target/arm/as3525/sansa-clip/lcd-as-clip.S

@@ -0,0 +1,99 @@
+/***************************************************************************
+ *             __________               __   ___.
+ *   Open      \______   \ ____   ____ |  | _\_ |__   _______  ___
+ *   Source     |       _//  _ \_/ ___\|  |/ /| __ \ /  _ \  \/  /
+ *   Jukebox    |    |   (  <_> )  \___|    < | \_\ (  <_> > <  <
+ *   Firmware   |____|_  /\____/ \___  >__|_ \|___  /\____/__/\_ \
+ *                     \/            \/     \/    \/            \/
+ * $Id$
+ *
+ * Copyright (C) 2008 by Jens Arnold
+ *
+ * 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 "as3525.h"
+
+    .text
+    .align      2
+
+    .global     lcd_grey_data
+    .type       lcd_grey_data,%function
+
+/* A high performance function to write grey phase data to the display,
+ * one or multiple pixels.
+ *
+ * Arguments:
+ *   r0 - pixel value data address
+ *   r1 - pixel phase data address
+ *   r2 - pixel block count
+ *
+ * Register usage:
+ *   r3/r4 - current block of phases
+ *   r5/r6 - current block of values
+ *   r7 - lcd data accumulator
+ *   r8 - phase signs mask
+ *   lr - lcd bridge address
+ */
+
+lcd_grey_data:
+    stmfd   sp!, {r4-r8, lr}
+    mov     r8, #0x80
+    orr     r8, r8, r8, lsl #8
+    orr     r8, r8, r8, lsl #16
+
+    ldr     lr, =GPIOA_BASE
+    mov     r3, #(1<<5)
+    str     r3, [lr, #(4*(1<<5))] @ set pin D/C# of LCD controller (data)
+
+    ldr     lr, =DBOP_BASE
+
+.greyloop:
+    ldmia   r1, {r3-r4}         /* Fetch 8 pixel phases */
+    ldmia   r0!, {r5-r6}        /* Fetch 8 pixel values */
+
+    mov     r7, #0xff
+    tst     r3, #0x80
+    biceq   r7, r7, #0x80
+    tst     r3, #0x8000
+    biceq   r7, r7, #0x40
+    tst     r3, #0x800000
+    biceq   r7, r7, #0x20
+    tst     r3, #0x80000000
+    biceq   r7, r7, #0x10
+    bic     r3, r3, r8
+    add     r3, r3, r5
+
+    tst     r4, #0x80
+    biceq   r7, r7, #0x08
+    tst     r4, #0x8000
+    biceq   r7, r7, #0x04
+    tst     r4, #0x800000
+    biceq   r7, r7, #0x02
+    tst     r4, #0x80000000
+    biceq   r7, r7, #0x01
+    bic     r4, r4, r8
+    add     r4, r4, r6
+
+    stmia   r1!, {r3-r4}
+
+    orr     r7, r7, r7, lsl #8  @ we set 15:13 to the MSb and 3:0 to the LSb
+    strh    r7, [lr, #0x10]     @ DBOP_DOUT
+
+1:
+    ldr     r5, [lr, #0xC]      @ DBOP_STAT
+    ands    r5, r5, #(1<<10)    @ wait until push fifo empties
+    beq     1b
+
+    subs    r2, r2, #1
+    bne     .greyloop
+
+    ldmfd   sp!, {r4-r8, pc}
+    .size   lcd_grey_data,.-lcd_grey_data

firmware/target/arm/as3525/sansa-clip/lcd-ssd1303.c

@@ -88,6 +88,7 @@ void lcd_write_command(int byte)
     GPIOA_PIN(5) = 0;
 
     /* Write command */
+    /* Only bits 15:12 and 3:0 of DBOP_DOUT are meaningful */
     DBOP_DOUT = (byte << 8) | byte;
 
     /* While push fifo is not empty */
@@ -103,6 +104,7 @@ void lcd_write_data(const fb_data* p_bytes, int count)
     while (count--)
     {
         /* Write pixels */
+        /* Only bits 15:12 and 3:0 of DBOP_DOUT are meaningful */
         DBOP_DOUT = (*p_bytes << 8) | *p_bytes;
 
         p_bytes++; /* next packed pixels */
@@ -266,26 +268,30 @@ void lcd_blit_mono(const unsigned char *data, int x, int by, int width,
     }
 }
 
+/* Helper function for lcd_grey_phase_blit(). */
+void lcd_grey_data(unsigned char *values, unsigned char *phases, int count);
 
 /* Performance function that works with an external buffer
    note that by and bheight are in 8-pixel units! */
 void lcd_blit_grey_phase(unsigned char *values, unsigned char *phases,
                          int x, int by, int width, int bheight, int stride)
 {
-    /* TODO */
-
-#if 0
     if(!display_on)
         return;
-#endif
 
-    (void)values;
-    (void)phases;
-    (void)x;
-    (void)by;
-    (void)width;
-    (void)bheight;
-    (void)stride;
+    stride <<= 3; /* 8 pixels per block */
+    /* Copy display bitmap to hardware */
+    while (bheight--)
+    {
+        lcd_write_command (LCD_CNTL_PAGE | (by++ & 0xf));
+        lcd_write_command (LCD_CNTL_HIGHCOL | (((x+2+xoffset)>>4) & 0xf));
+        lcd_write_command (LCD_CNTL_LOWCOL | ((x+2+xoffset) & 0xf));
+
+        lcd_grey_data(values, phases, width);
+
+        values += stride;
+        phases += stride;
+    }
 }
 
 /* Update the display.