[PATCH 2/4] rockchip: spl: Add a read_brom_bootsource_id() helper

[Jonas Karlman]

The bootsource ids reported by BootROM of RK3576 for e.g. SPI NOR and
USB differs slightly compared to prior SoCs:

- Booting from sfc0 (ROCK 4D) report the normal bootsource id 0x3.
- Booting from sfc1 M1 (NanoPi M5) report a new bootsource id 0x23.
- Booting from sfc1 M0 has not been tested (no board using this config).
- Booting from USB report a new bootsource id 0x81.

Add a helper function to read the bootsource id. This helper function
will be used to translate the new values to the common BROM_BOOTSOURCE
enum values on RK3576.

Signed-off-by: Jonas Karlman <jonas at kwiboo.se>
---
 arch/arm/include/asm/arch-rockchip/bootrom.h | 2 ++
 arch/arm/mach-rockchip/spl.c                 | 7 ++++++-
 2 files changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/arm/include/asm/arch-rockchip/bootrom.h b/arch/arm/include/asm/arch-rockchip/bootrom.h
index e736772fda75..b15938c021d6 100644
--- a/arch/arm/include/asm/arch-rockchip/bootrom.h
+++ b/arch/arm/include/asm/arch-rockchip/bootrom.h
@@ -64,4 +64,6 @@ extern const char * const boot_devices[BROM_LAST_BOOTSOURCE + 1];
  */
 #define BROM_BOOTSOURCE_ID_ADDR   (CFG_IRAM_BASE + 0x10)
 
+u32 read_brom_bootsource_id(void);
+
 #endif
diff --git a/arch/arm/mach-rockchip/spl.c b/arch/arm/mach-rockchip/spl.c
index f4d29bbdd17e..1ce3a3b05547 100644
--- a/arch/arm/mach-rockchip/spl.c
+++ b/arch/arm/mach-rockchip/spl.c
@@ -31,6 +31,11 @@ int board_return_to_bootrom(struct spl_image_info *spl_image,
 __weak const char * const boot_devices[BROM_LAST_BOOTSOURCE + 1] = {
 };
 
+__weak u32 read_brom_bootsource_id(void)
+{
+	return readl(BROM_BOOTSOURCE_ID_ADDR);
+}
+
 const char *board_spl_was_booted_from(void)
 {
 	static u32 brom_bootsource_id_cache = BROM_BOOTSOURCE_UNKNOWN;
@@ -40,7 +45,7 @@ const char *board_spl_was_booted_from(void)
 	if (brom_bootsource_id_cache != BROM_BOOTSOURCE_UNKNOWN)
 		bootdevice_brom_id = brom_bootsource_id_cache;
 	else
-		bootdevice_brom_id = readl(BROM_BOOTSOURCE_ID_ADDR);
+		bootdevice_brom_id = read_brom_bootsource_id();
 
 	if (bootdevice_brom_id < ARRAY_SIZE(boot_devices))
 		bootdevice_ofpath = boot_devices[bootdevice_brom_id];
-- 
2.49.0