Sansa c200v2: update DBOP button reading mechanism, this enables readout of the volume buttons, rec and hold button.

git-svn-id: svn://svn.rockbox.org/rockbox/trunk@22635 a1c6a512-1295-4272-9138-f99709370657

2 files changed, 62 insertions, 47 deletions

diff --git a/firmware/target/arm/as3525/sansa-c200v2/button-c200v2.c b/firmware/target/arm/as3525/sansa-c200v2/button-c200v2.c
index 965006ce61..b7ce7330c0 100644
--- a/firmware/target/arm/as3525/sansa-c200v2/button-c200v2.c
+++ b/firmware/target/arm/as3525/sansa-c200v2/button-c200v2.c
@@ -26,10 +26,10 @@
 #include "powermgmt.h"
 
 
-unsigned short _dbop_din    = 0;
+static unsigned short _dbop_din    = 0xFFFF;
 
 /* in the lcd driver */
-extern bool lcd_button_support(void);
+extern unsigned short int lcd_dbop_input(void);
 
 static bool hold_button     = false;
 #ifndef BOOTLOADER
@@ -52,26 +52,6 @@ bool button_hold(void)
     return hold_button;
 }
 
-static void button_read_dbop(void)
-{
-    /* Set up dbop for input */
-    DBOP_CTRL |= (1<<19);                /* Tri-state DBOP on read cycle */
-    DBOP_CTRL &= ~(1<<16);               /* disable output (1:write enabled) */
-    DBOP_TIMPOL_01 = 0xe167e167;         /* Set Timing & Polarity regs 0 & 1 */
-    DBOP_TIMPOL_23 = 0xe167006e;         /* Set Timing & Polarity regs 2 & 3 */
-
-    DBOP_CTRL |= (1<<15);                /* start read */
-    while (!(DBOP_STAT & (1<<16)));      /* wait for valid data */
-
-    _dbop_din = DBOP_DIN;                /* Read dbop data*/
-
-    /* Reset dbop for output */
-    DBOP_TIMPOL_01 = 0x6e167;            /* Set Timing & Polarity regs 0 & 1 */
-    DBOP_TIMPOL_23 = 0xa167e06f;         /* Set Timing & Polarity regs 2 & 3 */
-    DBOP_CTRL |= (1<<16);                /* Enable output (0:write disable)  */
-    DBOP_CTRL &= ~(1<<19);               /* Tri-state when no active write */
-}
-
 /*
  * Get button pressed from hardware
  */
@@ -79,13 +59,27 @@ int button_read_device(void)
 {
     int btn = BUTTON_NONE;
 
+    _dbop_din = lcd_dbop_input();
+
+    /* hold button handling */
+    hold_button = ((_dbop_din & (1<<12)) == 0);
+#ifndef BOOTLOADER
+    /* light handling */
+    if (hold_button != hold_button_old)
+    {
+        hold_button_old = hold_button;
+        backlight_hold_changed(hold_button);
+    }
+#endif /* BOOTLOADER */
+    if (hold_button) {
+        return 0;
+    }
+
     /* direct GPIO connections */
     if (GPIOA_PIN(3))
         btn |= BUTTON_POWER;
 
-    if(lcd_button_support())
-        button_read_dbop();
-
+    /* DBOP buttons */
     if(!(_dbop_din & (1<<2)))
         btn |= BUTTON_LEFT;
     if(!(_dbop_din & (1<<3)))
@@ -96,15 +90,12 @@ int button_read_device(void)
         btn |= BUTTON_UP;
     if(!(_dbop_din & (1<<6)))
         btn |= BUTTON_RIGHT;
-
-#ifndef BOOTLOADER
-    /* light handling */
-    if (hold_button != hold_button_old)
-    {
-        hold_button_old = hold_button;
-        backlight_hold_changed(hold_button);
-    }
-#endif /* BOOTLOADER */
+    if(!(_dbop_din & (1<<13)))
+        btn |= BUTTON_VOL_UP;
+    if(!(_dbop_din & (1<<14)))
+        btn |= BUTTON_VOL_DOWN;
+    if(!(_dbop_din & (1<<15)))
+        btn |= BUTTON_REC;
 
     return btn;
 }
diff --git a/firmware/target/arm/lcd-c200_c200v2.c b/firmware/target/arm/lcd-c200_c200v2.c
index 06cb475d9d..3ba1bf0f07 100644
--- a/firmware/target/arm/lcd-c200_c200v2.c
+++ b/firmware/target/arm/lcd-c200_c200v2.c
@@ -29,6 +29,7 @@
 #ifdef SANSA_C200V2
 /* button driver needs to know if a lcd operation is in progress */
 static bool lcd_busy = false;
+static unsigned short dbop_input = 0xFFFF;
 #endif
 
 /* Display status */
@@ -182,24 +183,45 @@ static inline void as3525_dbop_init(void)
     lcd_delay(20);
 }
 
-/* we need to set the DBOP_DOUT pins high, for correct dbop reads */
-bool lcd_button_support(void)
+static unsigned short lcd_dbop_read(void)
 {
-    const fb_data data = 0xffff;
-
-    if (lcd_busy)       /* we can't use dbop for reading if we are in the */
-        return false;   /* middle of a write operation */
+    unsigned int dbop_ctrl_old = DBOP_CTRL;
+    unsigned int dbop_timpol23_old = DBOP_TIMPOL_23;
+    unsigned int value;
+    
+    /* make sure that the DBOP FIFO is empty */
+    while ((DBOP_STAT & (1<<10)) == 0);
 
-    /* use out of screen coordinates */
-    lcd_send_command(R_X_ADDR_AREA, 0);
-    lcd_send_command(1, 0);
-    lcd_send_command(R_Y_ADDR_AREA, 0);
-    lcd_send_command(1, 0);
+    /* write DBOP_DOUT to pre-charge DBOP data lines with a high level */
+    DBOP_TIMPOL_23 = 0xe167e167;    /* no strobe towards lcd */
+    DBOP_CTRL = (1 << 16) |         /* enw=1 (enable write) */
+                (1 << 12);          /* ow=1 (16-bit data width) */
+    DBOP_DOUT = 0xFFFF;             /* all pins high */
+    while ((DBOP_STAT & (1<<10)) == 0);
 
-    lcd_write_data(&data, 1);
+    /* perform a DBOP read */
+    DBOP_CTRL = (1 << 15) |         /* strd=1 (start read) */
+                (1 << 12) |         /* ow=1 (16-bit data width) */
+                (31 << 0);          /* rs_t=31 (read DBOP at end of cycle) */
+    while ((DBOP_STAT & (1<<16)) == 0);
+    value = DBOP_DIN;
+    
+    /* restore previous values */
+    DBOP_TIMPOL_23 = dbop_timpol23_old;
+    DBOP_CTRL = dbop_ctrl_old;
+    
+    return value;
+}
 
-    return true;
+/* get the DBOP input value, either directly or cached if DBOP is busy */
+unsigned short int lcd_dbop_input(void)
+{
+    if (!lcd_busy) {
+        dbop_input = lcd_dbop_read();
+    }
+    return dbop_input;
 }
+
 #endif
 
 /* LCD init */
@@ -430,6 +452,8 @@ void lcd_update_rect(int x, int y, int width, int height)
 
 #ifdef SANSA_C200V2
     lcd_busy = true;
+    /* perform a dbop read before doing a potentially lengthy lcd update */
+    dbop_input = lcd_dbop_read();
 #endif
 
     if (width <= 1) {