arm: atmel: sama5d3: spl boot from fat fs SD card

Enable Atmel sama5d3xek boart spl boot support, which can load u-boot
from SD card with FAT file system.

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Andreas Bießmann <andreas.devel@googlemail.com>
diff --git a/arch/arm/cpu/at91-common/spl.c b/arch/arm/cpu/at91-common/spl.c
new file mode 100644
index 0000000..37c0cc4
--- /dev/null
+++ b/arch/arm/cpu/at91-common/spl.c
@@ -0,0 +1,90 @@
+/*
+ * Copyright (C) 2013 Atmel Corporation
+ *		      Bo Shen <voice.shen@atmel.com>
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include <common.h>
+#include <asm/io.h>
+#include <asm/arch/at91_common.h>
+#include <asm/arch/at91_pmc.h>
+#include <asm/arch/at91_wdt.h>
+#include <asm/arch/clk.h>
+#include <spl.h>
+
+static void at91_disable_wdt(void)
+{
+	struct at91_wdt *wdt = (struct at91_wdt *)ATMEL_BASE_WDT;
+
+	writel(AT91_WDT_MR_WDDIS, &wdt->mr);
+}
+
+void at91_plla_init(u32 pllar)
+{
+	struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
+
+	writel(pllar, &pmc->pllar);
+	while (!(readl(&pmc->sr) & (AT91_PMC_LOCKA | AT91_PMC_MCKRDY)))
+		;
+}
+
+void at91_mck_init(u32 mckr)
+{
+	struct at91_pmc *pmc = (struct at91_pmc *)ATMEL_BASE_PMC;
+	u32 tmp;
+
+	tmp = readl(&pmc->mckr);
+	tmp &= ~(AT91_PMC_MCKR_PRES_MASK |
+		 AT91_PMC_MCKR_MDIV_MASK |
+		 AT91_PMC_MCKR_PLLADIV_2);
+	tmp |= mckr & (AT91_PMC_MCKR_PRES_MASK |
+		       AT91_PMC_MCKR_MDIV_MASK |
+		       AT91_PMC_MCKR_PLLADIV_2);
+	writel(tmp, &pmc->mckr);
+
+	while (!(readl(&pmc->sr) & AT91_PMC_MCKRDY))
+		;
+}
+
+
+u32 spl_boot_device(void)
+{
+#ifdef CONFIG_SYS_USE_MMC
+	return BOOT_DEVICE_MMC1;
+#endif
+	return BOOT_DEVICE_NONE;
+}
+
+u32 spl_boot_mode(void)
+{
+	switch (spl_boot_device()) {
+#ifdef CONFIG_SYS_USE_MMC
+	case BOOT_DEVICE_MMC1:
+		return MMCSD_MODE_FAT;
+		break;
+#endif
+	case BOOT_DEVICE_NONE:
+	default:
+		hang();
+	}
+}
+
+void s_init(void)
+{
+	/* disable watchdog */
+	at91_disable_wdt();
+
+	/* PMC configuration */
+	at91_pmc_init();
+
+	at91_clock_init(CONFIG_SYS_AT91_MAIN_CLOCK);
+
+	timer_init();
+
+	board_early_init_f();
+
+	preloader_console_init();
+
+	mem_init();
+}