arm: K3: am654: Unlock control module registers during init

By default the device control module registers are locked,
preventing any writes to its registers.
Unlock those registers as part of the init flow.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Andreas Dannenberg <dannenberg@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>

arch/arm/mach-k3/am6_init.c

@@ -12,6 +12,41 @@
 #include <asm/arch/hardware.h>
 
 #ifdef CONFIG_SPL_BUILD
+static void mmr_unlock(u32 base, u32 partition)
+{
+	/* Translate the base address */
+	phys_addr_t part_base = base + partition * CTRL_MMR0_PARTITION_SIZE;
+
+	/* Unlock the requested partition if locked using two-step sequence */
+	writel(CTRLMMR_LOCK_KICK0_UNLOCK_VAL, part_base + CTRLMMR_LOCK_KICK0);
+	writel(CTRLMMR_LOCK_KICK1_UNLOCK_VAL, part_base + CTRLMMR_LOCK_KICK1);
+}
+
+static void ctrl_mmr_unlock(void)
+{
+	/* Unlock all WKUP_CTRL_MMR0 module registers */
+	mmr_unlock(WKUP_CTRL_MMR0_BASE, 0);
+	mmr_unlock(WKUP_CTRL_MMR0_BASE, 1);
+	mmr_unlock(WKUP_CTRL_MMR0_BASE, 2);
+	mmr_unlock(WKUP_CTRL_MMR0_BASE, 3);
+	mmr_unlock(WKUP_CTRL_MMR0_BASE, 6);
+	mmr_unlock(WKUP_CTRL_MMR0_BASE, 7);
+
+	/* Unlock all MCU_CTRL_MMR0 module registers */
+	mmr_unlock(MCU_CTRL_MMR0_BASE, 0);
+	mmr_unlock(MCU_CTRL_MMR0_BASE, 1);
+	mmr_unlock(MCU_CTRL_MMR0_BASE, 2);
+	mmr_unlock(MCU_CTRL_MMR0_BASE, 6);
+
+	/* Unlock all CTRL_MMR0 module registers */
+	mmr_unlock(CTRL_MMR0_BASE, 0);
+	mmr_unlock(CTRL_MMR0_BASE, 1);
+	mmr_unlock(CTRL_MMR0_BASE, 2);
+	mmr_unlock(CTRL_MMR0_BASE, 3);
+	mmr_unlock(CTRL_MMR0_BASE, 6);
+	mmr_unlock(CTRL_MMR0_BASE, 7);
+}
+
 static void store_boot_index_from_rom(void)
 {
 	u32 *boot_index = (u32 *)K3_BOOT_PARAM_TABLE_INDEX_VAL;
@@ -27,6 +62,9 @@ void board_init_f(ulong dummy)
 	 */
 	store_boot_index_from_rom();
 
+	/* Make all control module registers accessible */
+	ctrl_mmr_unlock();
+
 	/* Init DM early in-order to invoke system controller */
 	spl_early_init();
 

arch/arm/mach-k3/include/mach/am6_hardware.h

@@ -17,6 +17,27 @@
 #define CTRLMMR_MAIN_DEVSTAT_BKUP_BOOTMODE_MASK		GENMASK(6, 4)
 #define CTRLMMR_MAIN_DEVSTAT_BKUP_BOOTMODE_SHIFT	4
 
+#define WKUP_CTRL_MMR0_BASE				0x43000000
+#define MCU_CTRL_MMR0_BASE				0x40f00000
+
+/*
+ * The CTRL_MMR0 memory space is divided into several equally-spaced
+ * partitions, so defining the partition size allows us to determine
+ * register addresses common to those partitions.
+ */
+#define CTRL_MMR0_PARTITION_SIZE			0x4000
+
+/*
+ * CTRL_MMR0, WKUP_CTRL_MMR0, and MCU_CTR_MMR0 lock/kick-mechanism
+ * shared register definitions.
+ */
+#define CTRLMMR_LOCK_KICK0				0x01008
+#define CTRLMMR_LOCK_KICK0_UNLOCK_VAL			0x68ef3490
+#define CTRLMMR_LOCK_KICK0_UNLOCKED_MASK		BIT(0)
+#define CTRLMMR_LOCK_KICK0_UNLOCKED_SHIFT		0
+#define CTRLMMR_LOCK_KICK1				0x0100c
+#define CTRLMMR_LOCK_KICK1_UNLOCK_VAL			0xd172bc5a
+
 /* MCU SCRATCHPAD usage */
 #define K3_BOOT_PARAM_TABLE_INDEX_VAL	CONFIG_SYS_K3_MCU_SCRATCHPAD_BASE