[PATCH 3/3] arm: zynqmp: add boot source support

[Michael Riesch]

The ZynqMP reports the mode pins sampled at POR via the register
ZYNQMP_CRL_APB_BOOT_MODE_USER. This commit adds a function that reads
the register and populates the boot source.

Signed-off-by: Michael Riesch <michael.riesch at wolfvision.net>
---
 arch/arm/mach-zynqmp/zynqmp.c | 43 +++++++++++++++++++++++++++++++++++
 1 file changed, 43 insertions(+)

diff --git a/arch/arm/mach-zynqmp/zynqmp.c b/arch/arm/mach-zynqmp/zynqmp.c
index 5871c145b..262bc0dd4 100644
--- a/arch/arm/mach-zynqmp/zynqmp.c
+++ b/arch/arm/mach-zynqmp/zynqmp.c
@@ -6,9 +6,11 @@
 #include <common.h>
 #include <init.h>
 #include <linux/types.h>
+#include <bootsource.h>
 #include <reset_source.h>
 
 #define ZYNQMP_CRL_APB_BASE		0xff5e0000
+#define ZYNQMP_CRL_APB_BOOT_MODE_USER	(ZYNQMP_CRL_APB_BASE + 0x200)
 #define ZYNQMP_CRL_APB_RESET_REASON	(ZYNQMP_CRL_APB_BASE + 0x220)
 
 /* External POR: The PS_POR_B reset signal pin was asserted. */
@@ -26,6 +28,46 @@
 /* Software debugger reset: Write to BLOCKONLY_RST [debug_only]. */
 #define ZYNQMP_CRL_APB_RESET_REASON_DEBUG_SYS  BIT(6)
 
+struct zynqmp_bootsource {
+	enum bootsource src;
+	int instance;
+};
+
+/* cf. Table 11-1 "Boot Modes" in UG1085 Zynq UltraScale+ Device TRM */
+static struct zynqmp_bootsource boot_modes[] = {
+	{ .src = BOOTSOURCE_JTAG, .instance = 0 },
+	{ .src = BOOTSOURCE_SPI, .instance = 0 },
+	{ .src = BOOTSOURCE_SPI, .instance = 0 },
+	{ .src = BOOTSOURCE_MMC, .instance = 0 },
+	{ .src = BOOTSOURCE_SPI_NAND, .instance = 0 },
+	{ .src = BOOTSOURCE_MMC, .instance = 1 },
+	{ .src = BOOTSOURCE_MMC, .instance = 0 },
+	{ .src = BOOTSOURCE_USB, .instance = 0 },
+	{ .src = BOOTSOURCE_JTAG, .instance = 0 },
+	{ .src = BOOTSOURCE_JTAG, .instance = 0 },
+	{ .src = BOOTSOURCE_UNKNOWN, .instance = 0 },
+	{ .src = BOOTSOURCE_UNKNOWN, .instance = 0 },
+	{ .src = BOOTSOURCE_UNKNOWN, .instance = 0 },
+	{ .src = BOOTSOURCE_UNKNOWN, .instance = 0 },
+	{ .src = BOOTSOURCE_MMC, .instance = 1 },
+};
+
+static enum bootsource zynqmp_bootsource(void)
+{
+	u32 v;
+
+	v = readl(ZYNQMP_CRL_APB_BOOT_MODE_USER);
+	v &= 0x0F;
+
+	if (v >= ARRAY_SIZE(boot_modes))
+		return BOOTSOURCE_UNKNOWN;
+
+	bootsource_set(boot_modes[v].src);
+	bootsource_set_instance(boot_modes[v].instance);
+
+	return boot_modes[v].src;
+}
+
 struct zynqmp_reset_reason {
 	u32 mask;
 	enum reset_src_type type;
@@ -65,6 +107,7 @@ static enum reset_src_type zynqmp_get_reset_src(void)
 
 static int zynqmp_init(void)
 {
+	zynqmp_bootsource();
 	reset_source_set(zynqmp_get_reset_src());
 
 	return 0;
-- 
2.17.1