ARM: at91: sfr: implement DDR input buffers open function

Add a function in SFR implementation that will open the DDR input
buffers.
This can be called at DRAM initialization time.

Signed-off-by: Eugen Hristev <eugen.hristev@microchip.com>

arch/arm/mach-at91/atmel_sfr.c

@@ -29,3 +29,14 @@ void configure_2nd_sram_as_l2_cache(void)
 }
 #endif
 
+void configure_ddrcfg_input_buffers(bool open)
+{
+	struct atmel_sfr *sfr = (struct atmel_sfr *)ATMEL_BASE_SFR;
+
+	if (open)
+		writel(ATMEL_SFR_DDRCFG_FDQIEN | ATMEL_SFR_DDRCFG_FDQSIEN,
+		       &sfr->ddrcfg);
+	else
+		writel(0, &sfr->ddrcfg);
+}
+

arch/arm/mach-at91/include/mach/at91_common.h

@@ -35,6 +35,9 @@ void at91_disable_wdt(void);
 void matrix_init(void);
 void redirect_int_from_saic_to_aic(void);
 void configure_2nd_sram_as_l2_cache(void);
+#ifdef CONFIG_ATMEL_SFR
+void configure_ddrcfg_input_buffers(bool open);
+#endif
 
 int at91_set_ethaddr(int offset);
 int at91_video_show_board_info(void);