stpmic1: program pmic to keep only the debug unit on

Depending on backup register value, we maintain the debug unit
powered-on for debugging purpose.
Only BUCK1 is required for powering the debug unit, so revert
the setting for all the other power lanes, except BUCK3 that
has to be always on.
Signed-off-by: NPatrick Delaunay <patrick.delaunay@st.com>

arch/arm/mach-stm32mp/include/mach/stm32.h

@@ -94,6 +94,7 @@ enum boot_device {
 #define TAMP_BOOT_DEVICE_MASK		GENMASK(7, 4)
 #define TAMP_BOOT_INSTANCE_MASK		GENMASK(3, 0)
 #define TAMP_BOOT_FORCED_MASK		GENMASK(7, 0)
+#define TAMP_BOOT_DEBUG_ON		BIT(16)
 
 enum forced_boot_mode {
 	BOOT_NORMAL = 0x00,

board/st/stm32mp1/spl.c

@@ -27,5 +27,19 @@ void spl_board_init(void)
 				STPMIC1_BUCKS_MRST_CR,
 				STPMIC1_MRST_BUCK(STPMIC1_BUCK3),
 				STPMIC1_MRST_BUCK(STPMIC1_BUCK3));
+
+	/* Check if debug is enabled to program PMIC according to the bit */
+	if ((readl(TAMP_BOOT_CONTEXT) & TAMP_BOOT_DEBUG_ON) && !ret) {
+		printf("Keep debug unit ON\n");
+
+		pmic_clrsetbits(dev, STPMIC1_BUCKS_MRST_CR,
+				STPMIC1_MRST_BUCK_DEBUG,
+				STPMIC1_MRST_BUCK_DEBUG);
+
+		if (STPMIC1_MRST_LDO_DEBUG)
+			pmic_clrsetbits(dev, STPMIC1_LDOS_MRST_CR,
+					STPMIC1_MRST_LDO_DEBUG,
+					STPMIC1_MRST_LDO_DEBUG);
+	}
 #endif
 }

include/power/stpmic1.h

@@ -22,11 +22,12 @@
 
 /* BUCKS_MRST_CR */
 #define STPMIC1_MRST_BUCK(buck)		BIT(buck)
-#define STPMIC1_MRST_BUCK_ALL		GENMASK(3, 0)
+#define STPMIC1_MRST_BUCK_DEBUG		(STPMIC1_MRST_BUCK(STPMIC1_BUCK1) | \
+					 STPMIC1_MRST_BUCK(STPMIC1_BUCK3))
 
 /* LDOS_MRST_CR */
 #define STPMIC1_MRST_LDO(ldo)		BIT(ldo)
-#define STPMIC1_MRST_LDO_ALL		GENMASK(6, 0)
+#define STPMIC1_MRST_LDO_DEBUG		0
 
 /* BUCKx_MAIN_CR (x=1...4) */
 #define STPMIC1_BUCK_ENA		BIT(0)