Samsung YP-R0 LCD improvements

This patch adds to YP-R0 (and other future targets using Linux
framebuffer) the ability to use LCD_ENABLE to save some CPU cycles
while display is powered off.
This patch also changes the way to toggle LCD power: now using
a proper ioctl call, slightly more efficient.

Change-Id: I544de77f5abd4ac1c13d3fe3a6e40a30f7c0bece
Reviewed-on: http://gerrit.rockbox.org/410
Reviewed-by: Thomas Martitz <kugel@rockbox.org>

firmware/export/config/samsungypr0.h

@@ -21,9 +21,12 @@
 /* define this if you have a colour LCD */
 #define HAVE_LCD_COLOR
 
-/* define this if the LCD needs to be shutdown */
+/* Define this if the LCD can shut down */
 #define HAVE_LCD_SHUTDOWN
 
+/* define this if you have LCD enable function */
+#define HAVE_LCD_ENABLE
+
 /* define this if you want album art for this target */
 #define HAVE_ALBUMART
 

firmware/target/hosted/samsungypr/lcd-target.h

@@ -22,5 +22,8 @@
 
 extern fb_data *dev_fb;
 #define LCD_FRAMEBUF_ADDR(col, row) (dev_fb + row*LCD_WIDTH + col)
-
+#ifdef HAVE_LCD_ENABLE
+extern void lcd_set_active(bool active);
+extern void lcd_enable(bool enable);
+#endif
 #endif

firmware/target/hosted/samsungypr/lcd-ypr.c

@@ -8,6 +8,7 @@
  * $Id: lcd-bitmap.c 29248 2011-02-08 20:05:25Z thomasjfox $
  *
  * Copyright (C) 2011 Lorenzo Miori, Thomas Martitz
+ * Copyright (C) 2013 Lorenzo Miori
  *
  * This program is free software; you can redistribute it and/or
  * modify it under the terms of the GNU General Public License
@@ -22,26 +23,28 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <stdio.h>
-#include "string.h"
 #include <linux/fb.h>
 #include <sys/mman.h>
 #include <sys/ioctl.h>
-
+#include "config.h"
 #include "file.h"
 #include "debug.h"
 #include "system.h"
 #include "screendump.h"
 #include "lcd.h"
+#include "lcd-target.h"
 
 static int dev_fd = 0;
 fb_data *dev_fb = 0;
 
+#ifdef HAVE_LCD_SHUTDOWN
 void lcd_shutdown(void)
 {
     printf("FB closed.");
     munmap(dev_fb, FRAMEBUFFER_SIZE);
     close(dev_fd);
 }
+#endif
 
 void lcd_init_device(void)
 {
@@ -69,7 +72,7 @@ void lcd_init_device(void)
         exit(3);
     }
 
-    vinfo.bits_per_pixel = 16;
+    vinfo.bits_per_pixel = LCD_DEPTH;
 
     if (ioctl(dev_fd, FBIOPUT_VSCREENINFO, &vinfo)) {
             perror("fbset(ioctl)");
@@ -80,8 +83,7 @@ void lcd_init_device(void)
 
     /* Figure out the size of the screen in bytes */
     screensize = vinfo.xres * vinfo.yres * vinfo.bits_per_pixel / 8;
-    if (screensize != FRAMEBUFFER_SIZE)
-    {
+    if (screensize != FRAMEBUFFER_SIZE) {
         exit(4);
         perror("Display and framebuffer mismatch!\n");
     }
@@ -93,4 +95,26 @@ void lcd_init_device(void)
         exit(4);
     }
     printf("The framebuffer device was mapped to memory successfully.\n");
+
+    /* Be sure to turn on display at startup */
+    ioctl(dev_fd, FBIOBLANK, VESA_NO_BLANKING);
+#ifdef HAVE_LCD_ENABLE
+    lcd_set_active(true);
+#endif
 }
+
+#ifdef HAVE_LCD_ENABLE
+void lcd_enable(bool enable)
+ {
+    if (lcd_active() == enable)
+        return;
+
+    lcd_set_active(enable);
+
+    /* Turn on or off the display using Linux interface */
+    ioctl(dev_fd, FBIOBLANK, enable ? VESA_NO_BLANKING : VESA_POWERDOWN);
+
+    if (enable)
+        send_event(LCD_EVENT_ACTIVATION, NULL);
+}
+#endif

firmware/target/hosted/samsungypr/ypr0/backlight-ypr0.c

@@ -29,22 +29,6 @@
 
 static bool backlight_on_status = true; /* Is on or off? */
 
-/*TODO: see if LCD sleep could be implemented in a better way -> ie using a rockbox feature */
-/* Turn off LCD power supply */
-static void _backlight_lcd_sleep(void)
-{
-    int fp = open("/sys/class/graphics/fb0/blank", O_RDWR);
-    write(fp, "1", 1);
-    close(fp);
-}
-/* Turn on LCD screen */
-static void _backlight_lcd_power(void)
-{
-    int fp = open("/sys/class/graphics/fb0/blank", O_RDWR);
-    write(fp, "0", 1);
-    close(fp);
-}
-
 bool _backlight_init(void)
 {
     /* We have nothing to do */
@@ -56,7 +40,9 @@ void _backlight_on(void)
     if (!backlight_on_status)
     {
         /* Turn on lcd power before backlight */
-        _backlight_lcd_power();
+#ifdef HAVE_LCD_ENABLE
+        lcd_enable(true);
+#endif
         /* Original app sets this to 0xb1 when backlight is on... */
         ascodec_write_pmu(AS3543_BACKLIGHT, 0x1, 0xb1);
     }
@@ -67,11 +53,14 @@ void _backlight_on(void)
 
 void _backlight_off(void)
 {
-    if (backlight_on_status) {
+    if (backlight_on_status)
+    {
         /* Disabling the DCDC15 completely, keeps brightness register value */
         ascodec_write_pmu(AS3543_BACKLIGHT, 0x1, 0x00);
         /* Turn off lcd power then */
-        _backlight_lcd_sleep();
+#ifdef HAVE_LCD_ENABLE
+        lcd_enable(false);
+#endif
     }
 
     backlight_on_status = false;