stm32mp: add function to retrieve VDD regulator

Add function to find from device tree the proper regulator
that controls the VDD domain. Rework the dt_get_cpu_regulator_name
to use the same generic function.

Signed-off-by: Lionel Debieve <lionel.debieve@st.com>
Change-Id: I75f96d30a408f6d10182fc780bc40c3971b6095f
Reviewed-on: https://gerrit.st.com/c/mpu/oe/st/tf-a/+/185334


Reviewed-by: CITOOLS <smet-aci-reviews@lists.codex.cro.st.com>
Reviewed-by: CIBUILD <smet-aci-builds@lists.codex.cro.st.com>
Reviewed-by: Yann GAUTIER <yann.gautier@st.com>

plat/st/common/include/stm32mp_common.h

@@ -25,6 +25,7 @@ bool stm32mp_is_closed_device(void);
 bool stm32mp_is_auth_supported(void);
 
 const char *stm32mp_get_cpu_supply_name(void);
+const char *stm32mp_get_vdd_supply_name(void);
 
 /* Return the base address of the DDR controller */
 uintptr_t stm32mp_ddrctrl_base(void);

plat/st/common/include/stm32mp_dt.h

 /*
  * Copyright (c) 2020, STMicroelectronics - All Rights Reserved
- * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2020, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -44,6 +44,7 @@ int dt_get_max_opp_freqvolt(uint32_t *freq_khz, uint32_t *voltage_mv);
 int dt_get_all_opp_freqvolt(uint32_t *count, uint32_t *freq_khz_array,
 			    uint32_t *voltage_mv_array);
 uint32_t dt_get_pwr_vdd_voltage(void);
+const char *dt_get_vdd_regulator_name(void);
 const char *dt_get_cpu_regulator_name(void);
 const char *dt_get_board_model(void);
 int fdt_get_gpio_bank_pin_count(unsigned int bank);

plat/st/common/stm32mp_common.c

@@ -167,6 +167,22 @@ const char *stm32mp_get_cpu_supply_name(void)
 	return supply;
 }
 
+/* Return VDD supply name */
+const char *stm32mp_get_vdd_supply_name(void)
+{
+	const char *supply = NULL;
+
+	if (dt_pmic_status() > 0) {
+		const char *regulator = dt_get_vdd_regulator_name();
+
+		if (regulator != NULL) {
+			dt_pmic_find_supply(&supply, regulator);
+		}
+	}
+
+	return supply;
+}
+
 #if TRUSTED_BOARD_BOOT && STM32MP_USE_STM32IMAGE
 /* Save pointer to last loaded header */
 static boot_api_image_header_t *latest_stm32_header;

plat/st/common/stm32mp_dt.c

@@ -485,20 +485,17 @@ uint32_t dt_get_pwr_vdd_voltage(void)
 }
 
 /*******************************************************************************
- * This function retrieves CPU regulator name from DT.
- * Returns string taken from supply node, NULL otherwise.
+ * This function return the real regulator name from DT.
  ******************************************************************************/
-const char *dt_get_cpu_regulator_name(void)
+static const char *dt_get_regulator_name(int node, const char *regu_name)
 {
-	int node;
 	const fdt32_t *cuint;
 
-	node = fdt_path_offset(fdt, "/cpus/cpu@0");
-	if (node < 0) {
+	if ((node < 0) || (regu_name == NULL)) {
 		return NULL;
 	}
 
-	cuint = fdt_getprop(fdt, node, "cpu-supply", NULL);
+	cuint = fdt_getprop(fdt, node, regu_name, NULL);
 	if (cuint == NULL) {
 		return NULL;
 	}
@@ -511,6 +508,36 @@ const char *dt_get_cpu_regulator_name(void)
 	return (const char *)fdt_getprop(fdt, node, "regulator-name", NULL);
 }
 
+/*******************************************************************************
+ * This function retrieves VDD regulator name from DT.
+ * Returns string taken from supply node, NULL otherwise.
+ ******************************************************************************/
+const char *dt_get_vdd_regulator_name(void)
+{
+	int node = fdt_node_offset_by_compatible(fdt, -1, DT_PWR_COMPAT);
+
+	if (node < 0) {
+		return NULL;
+	}
+
+	return dt_get_regulator_name(node, "vdd-supply");
+}
+
+/*******************************************************************************
+ * This function retrieves CPU regulator name from DT.
+ * Returns string taken from supply node, NULL otherwise.
+ ******************************************************************************/
+const char *dt_get_cpu_regulator_name(void)
+{
+	int node = fdt_path_offset(fdt, "/cpus/cpu@0");
+
+	if (node < 0) {
+		return NULL;
+	}
+
+	return dt_get_regulator_name(node, "cpu-supply");
+}
+
 /*******************************************************************************
  * This function retrieves board model from DT
  * Returns string taken from model node, NULL otherwise