ARM: at91: add code for sama5 boot source detection

SAMA5 BootROM passes information about the boot source in the r4
register. Add functions to parse these. To make use of this, entry point
must back up the r4 register, because otherwise it's clobbered by local
variable use.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

1 files changed, 46 insertions, 0 deletions

diff --git a/arch/arm/mach-at91/include/mach/sama5_bootsource.h b/arch/arm/mach-at91/include/mach/sama5_bootsource.h
new file mode 100644
index 0000000000..29354dcaf3
--- /dev/null
+++ b/arch/arm/mach-at91/include/mach/sama5_bootsource.h
@@ -0,0 +1,46 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef AT91_SAMA5_BOOTSOURCE_H_
+#define AT91_SAMA5_BOOTSOURCE_H_
+
+#include <errno.h>
+#include <bootsource.h>
+#include <linux/bitops.h>
+#include <linux/bitfield.h>
+#include <mach/hardware.h>
+
+/* Boot modes stored by BootROM in r4 */
+#define SAMA5_BOOTSOURCE_SPI	0
+#define SAMA5_BOOTSOURCE_MCI	1
+#define SAMA5_BOOTSOURCE_SMC	2
+#define SAMA5_BOOTSOURCE_TWI	3
+#define SAMA5_BOOTSOURCE_QSPI	4
+#define SAMA5_BOOTSOURCE_SAM_BA	7
+
+#define SAMA5_BOOTSOURCE		GENMASK(3, 0)
+#define SAMA5_BOOTSOURCE_INSTANCE	GENMASK(7, 4)
+
+static inline int sama5_bootsource(u32 reg)
+{
+	u32 dev = FIELD_GET(SAMA5_BOOTSOURCE, reg);
+
+	switch(dev) {
+	case SAMA5_BOOTSOURCE_MCI:
+		return BOOTSOURCE_MMC;
+	case SAMA5_BOOTSOURCE_SPI:
+		return BOOTSOURCE_SPI_NOR;
+	case SAMA5_BOOTSOURCE_QSPI:
+		return BOOTSOURCE_SPI;
+	case SAMA5_BOOTSOURCE_SMC:
+		return BOOTSOURCE_NAND;
+	case SAMA5_BOOTSOURCE_SAM_BA:
+		return BOOTSOURCE_SERIAL;
+	}
+	return BOOTSOURCE_UNKNOWN;
+}
+
+static inline int sama5_bootsource_instance(u32 reg)
+{
+	return FIELD_GET(SAMA5_BOOTSOURCE_INSTANCE, reg);
+}
+
+#endif