Merge changes from topic "allwinner_pmic" into integration

* changes:
  allwinner: Convert AXP803 regulator setup code into a driver
  allwinner: a64: power: Use fdt_for_each_subnode
  allwinner: a64: power: Remove obsolete register check
  allwinner: a64: power: Remove duplicate DT check
  allwinner: Build PMIC bus drivers only in BL31
  allwinner: a64: power: Make sunxi_turn_off_soc static
  allwinner: Merge duplicate code in sunxi_power_down
  allwinner: Clean up PMIC-related error handling
  allwinner: Synchronize PMIC enumerations
  allwinner: Enable clock before resetting I2C/RSB

drivers/allwinner/axp/axp803.c

+/*
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <drivers/allwinner/axp.h>
+
+const uint8_t axp_chip_id = AXP803_CHIP_ID;
+const char *const axp_compatible = "x-powers,axp803";
+
+const struct axp_regulator axp_regulators[] = {
+	{"dcdc1", 1600, 3400, 100, NA, 0x20, 0x10, 0},
+	{"dcdc5",  800, 1840,  10, 32, 0x24, 0x10, 4},
+	{"dcdc6",  600, 1520,  10, 50, 0x25, 0x10, 5},
+	{"dldo1",  700, 3300, 100, NA, 0x15, 0x12, 3},
+	{"dldo2",  700, 4200, 100, 27, 0x16, 0x12, 4},
+	{"dldo3",  700, 3300, 100, NA, 0x17, 0x12, 5},
+	{"dldo4",  700, 3300, 100, NA, 0x18, 0x12, 6},
+	{"fldo1",  700, 1450,  50, NA, 0x1c, 0x13, 2},
+	{}
+};

drivers/allwinner/axp/common.c

+/*
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#include <errno.h>
+
+#include <libfdt.h>
+
+#include <common/debug.h>
+#include <drivers/allwinner/axp.h>
+
+int axp_check_id(void)
+{
+	int ret;
+
+	ret = axp_read(0x03);
+	if (ret < 0)
+		return ret;
+
+	ret &= 0xcf;
+	if (ret != axp_chip_id) {
+		ERROR("PMIC: Found unknown PMIC %02x\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+
+int axp_clrsetbits(uint8_t reg, uint8_t clr_mask, uint8_t set_mask)
+{
+	uint8_t val;
+	int ret;
+
+	ret = axp_read(reg);
+	if (ret < 0)
+		return ret;
+
+	val = (ret & ~clr_mask) | set_mask;
+
+	return axp_write(reg, val);
+}
+
+void axp_power_off(void)
+{
+	/* Set "power disable control" bit */
+	axp_setbits(0x32, BIT(7));
+}
+
+/*
+ * Retrieve the voltage from a given regulator DTB node.
+ * Both the regulator-{min,max}-microvolt properties must be present and
+ * have the same value. Return that value in millivolts.
+ */
+static int fdt_get_regulator_millivolt(const void *fdt, int node)
+{
+	const fdt32_t *prop;
+	uint32_t min_volt;
+
+	prop = fdt_getprop(fdt, node, "regulator-min-microvolt", NULL);
+	if (prop == NULL)
+		return -EINVAL;
+	min_volt = fdt32_to_cpu(*prop);
+
+	prop = fdt_getprop(fdt, node, "regulator-max-microvolt", NULL);
+	if (prop == NULL)
+		return -EINVAL;
+
+	if (fdt32_to_cpu(*prop) != min_volt)
+		return -EINVAL;
+
+	return min_volt / 1000;
+}
+
+static int setup_regulator(const void *fdt, int node,
+			   const struct axp_regulator *reg)
+{
+	uint8_t val;
+	int mvolt;
+
+	mvolt = fdt_get_regulator_millivolt(fdt, node);
+	if (mvolt < reg->min_volt || mvolt > reg->max_volt)
+		return -EINVAL;
+
+	val = (mvolt / reg->step) - (reg->min_volt / reg->step);
+	if (val > reg->split)
+		val = ((val - reg->split) / 2) + reg->split;
+
+	axp_write(reg->volt_reg, val);
+	axp_setbits(reg->switch_reg, BIT(reg->switch_bit));
+
+	INFO("PMIC: %s voltage: %d.%03dV\n", reg->dt_name,
+	     mvolt / 1000, mvolt % 1000);
+
+	return 0;
+}
+
+static bool should_enable_regulator(const void *fdt, int node)
+{
+	if (fdt_getprop(fdt, node, "phandle", NULL) != NULL)
+		return true;
+	if (fdt_getprop(fdt, node, "regulator-always-on", NULL) != NULL)
+		return true;
+	return false;
+}
+
+void axp_setup_regulators(const void *fdt)
+{
+	int node;
+	bool dc1sw = false;
+
+	if (fdt == NULL)
+		return;
+
+	/* locate the PMIC DT node, bail out if not found */
+	node = fdt_node_offset_by_compatible(fdt, -1, axp_compatible);
+	if (node < 0) {
+		WARN("PMIC: No PMIC DT node, skipping setup\n");
+		return;
+	}
+
+	if (fdt_getprop(fdt, node, "x-powers,drive-vbus-en", NULL)) {
+		axp_clrbits(0x8f, BIT(4));
+		axp_setbits(0x30, BIT(2));
+		INFO("PMIC: Enabling DRIVEVBUS\n");
+	}
+
+	/* descend into the "regulators" subnode */
+	node = fdt_subnode_offset(fdt, node, "regulators");
+	if (node < 0) {
+		WARN("PMIC: No regulators DT node, skipping setup\n");
+		return;
+	}
+
+	/* iterate over all regulators to find used ones */
+	fdt_for_each_subnode(node, fdt, node) {
+		const struct axp_regulator *reg;
+		const char *name;
+		int length;
+
+		/* We only care if it's always on or referenced. */
+		if (!should_enable_regulator(fdt, node))
+			continue;
+
+		name = fdt_get_name(fdt, node, &length);
+		for (reg = axp_regulators; reg->dt_name; reg++) {
+			if (!strncmp(name, reg->dt_name, length)) {
+				setup_regulator(fdt, node, reg);
+				break;
+			}
+		}
+
+		if (!strncmp(name, "dc1sw", length)) {
+			/* Delay DC1SW enablement to avoid overheating. */
+			dc1sw = true;
+			continue;
+		}
+	}
+
+	/*
+	 * If DLDO2 is enabled after DC1SW, the PMIC overheats and shuts
+	 * down. So always enable DC1SW as the very last regulator.
+	 */
+	if (dc1sw) {
+		INFO("PMIC: Enabling DC1SW\n");
+		axp_setbits(0x12, BIT(7));
+	}
+}

include/drivers/allwinner/axp.h

+/*
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
+ *
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef AXP_H
+#define AXP_H
+
+#include <stdint.h>
+
+#define NA 0xff
+
+enum {
+	AXP803_CHIP_ID = 0x41,
+};
+
+struct axp_regulator {
+	const char *dt_name;
+	uint16_t min_volt;
+	uint16_t max_volt;
+	uint16_t step;
+	unsigned char split;
+	unsigned char volt_reg;
+	unsigned char switch_reg;
+	unsigned char switch_bit;
+};
+
+extern const uint8_t axp_chip_id;
+extern const char *const axp_compatible;
+extern const struct axp_regulator axp_regulators[];
+
+/*
+ * Since the PMIC can be connected to multiple bus types,
+ * low-level read/write functions must be provided by the platform
+ */
+int axp_read(uint8_t reg);
+int axp_write(uint8_t reg, uint8_t val);
+int axp_clrsetbits(uint8_t reg, uint8_t clr_mask, uint8_t set_mask);
+#define axp_clrbits(reg, clr_mask) axp_clrsetbits(reg, clr_mask, 0)
+#define axp_setbits(reg, set_mask) axp_clrsetbits(reg, 0, set_mask)
+
+int axp_check_id(void);
+void axp_power_off(void);
+void axp_setup_regulators(const void *fdt);
+
+#endif /* AXP_H */

plat/allwinner/common/include/sunxi_private.h

@@ -12,7 +12,7 @@ void sunxi_configure_mmu_el3(int flags);
 void sunxi_cpu_on(u_register_t mpidr);
 void sunxi_cpu_off(u_register_t mpidr);
 void sunxi_disable_secondary_cpus(u_register_t primary_mpidr);
-void __dead2 sunxi_power_down(void);
+void sunxi_power_down(void);
 
 int sunxi_pmic_setup(uint16_t socid, const void *fdt);
 void sunxi_security_setup(void);

plat/allwinner/common/sunxi_common.c

@@ -150,16 +150,16 @@ int sunxi_init_platform_r_twi(uint16_t socid, bool use_rsb)
 	/* set both pins to pull-up */
 	mmio_clrsetbits_32(SUNXI_R_PIO_BASE + 0x1c, 0x0fU, 0x5U);
 
-	/* assert, then de-assert reset of I2C/RSB controller */
-	mmio_clrbits_32(SUNXI_R_PRCM_BASE + reset_offset, device_bit);
-	mmio_setbits_32(SUNXI_R_PRCM_BASE + reset_offset, device_bit);
-
 	/* un-gate clock */
 	if (socid != SUNXI_SOC_H6)
 		mmio_setbits_32(SUNXI_R_PRCM_BASE + 0x28, device_bit);
 	else
 		mmio_setbits_32(SUNXI_R_PRCM_BASE + 0x19c, device_bit | BIT(0));
 
+	/* assert, then de-assert reset of I2C/RSB controller */
+	mmio_clrbits_32(SUNXI_R_PRCM_BASE + reset_offset, device_bit);
+	mmio_setbits_32(SUNXI_R_PRCM_BASE + reset_offset, device_bit);
+
 	return 0;
 }
 

plat/allwinner/common/sunxi_pm.c

 /*
- * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
  *
  * SPDX-License-Identifier: BSD-3-Clause
  */
@@ -65,6 +65,11 @@ static void __dead2 sunxi_system_off(void)
 	sunxi_disable_secondary_cpus(read_mpidr());
 
 	sunxi_power_down();
+
+	udelay(1000);
+	ERROR("PSCI: Cannot turn off system, halting\n");
+	wfi();
+	panic();
 }
 
 static void __dead2 sunxi_system_reset(void)

plat/allwinner/sun50i_a64/platform.mk

 #
-# Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -7,4 +7,6 @@
 # The differences between the platform are covered by the include files.
 include plat/allwinner/common/allwinner-common.mk
 
-PLAT_BL_COMMON_SOURCES	+=	drivers/allwinner/sunxi_rsb.c
+BL31_SOURCES		+=	drivers/allwinner/axp/axp803.c		\
+				drivers/allwinner/axp/common.c		\
+				drivers/allwinner/sunxi_rsb.c

plat/allwinner/sun50i_a64/sunxi_power.c

 /*
- * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
  * Copyright (c) 2018, Icenowy Zheng <icenowy@aosc.io>
  *
  * SPDX-License-Identifier: BSD-3-Clause
@@ -7,14 +7,11 @@
 
 #include <errno.h>
 
-#include <libfdt.h>
-
 #include <platform_def.h>
 
-#include <arch_helpers.h>
 #include <common/debug.h>
+#include <drivers/allwinner/axp.h>
 #include <drivers/allwinner/sunxi_rsb.h>
-#include <drivers/delay_timer.h>
 #include <lib/mmio.h>
 
 #include <sunxi_def.h>
@@ -22,6 +19,7 @@
 #include <sunxi_private.h>
 
 static enum pmic_type {
+	UNKNOWN,
 	GENERIC_H5,
 	GENERIC_A64,
 	REF_DESIGN_H5,	/* regulators controlled by GPIO pins on port L */
@@ -38,7 +36,7 @@ static enum pmic_type {
  * disabled.
  * This function only cares about peripherals.
  */
-void sunxi_turn_off_soc(uint16_t socid)
+static void sunxi_turn_off_soc(uint16_t socid)
 {
 	int i;
 
@@ -113,175 +111,22 @@ static int rsb_init(void)
 		return ret;
 
 	/* Associate the 8-bit runtime address with the 12-bit bus address. */
-	return rsb_assign_runtime_address(AXP803_HW_ADDR,
-					  AXP803_RT_ADDR);
-}
-
-static int axp_write(uint8_t reg, uint8_t val)
-{
-	return rsb_write(AXP803_RT_ADDR, reg, val);
-}
-
-static int axp_clrsetbits(uint8_t reg, uint8_t clr_mask, uint8_t set_mask)
-{
-	uint8_t regval;
-	int ret;
-
-	ret = rsb_read(AXP803_RT_ADDR, reg);
-	if (ret < 0)
+	ret = rsb_assign_runtime_address(AXP803_HW_ADDR,
+					 AXP803_RT_ADDR);
+	if (ret)
 		return ret;
 
-	regval = (ret & ~clr_mask) | set_mask;
-
-	return rsb_write(AXP803_RT_ADDR, reg, regval);
+	return axp_check_id();
 }
 
-#define axp_clrbits(reg, clr_mask) axp_clrsetbits(reg, clr_mask, 0)
-#define axp_setbits(reg, set_mask) axp_clrsetbits(reg, 0, set_mask)
-
-static bool should_enable_regulator(const void *fdt, int node)
+int axp_read(uint8_t reg)
 {
-	if (fdt_getprop(fdt, node, "phandle", NULL) != NULL)
-		return true;
-	if (fdt_getprop(fdt, node, "regulator-always-on", NULL) != NULL)
-		return true;
-	return false;
+	return rsb_read(AXP803_RT_ADDR, reg);
 }
 
-/*
- * Retrieve the voltage from a given regulator DTB node.
- * Both the regulator-{min,max}-microvolt properties must be present and
- * have the same value. Return that value in millivolts.
- */
-static int fdt_get_regulator_millivolt(const void *fdt, int node)
-{
-	const fdt32_t *prop;
-	uint32_t min_volt;
-
-	prop = fdt_getprop(fdt, node, "regulator-min-microvolt", NULL);
-	if (prop == NULL)
-		return -EINVAL;
-	min_volt = fdt32_to_cpu(*prop);
-
-	prop = fdt_getprop(fdt, node, "regulator-max-microvolt", NULL);
-	if (prop == NULL)
-		return -EINVAL;
-
-	if (fdt32_to_cpu(*prop) != min_volt)
-		return -EINVAL;
-
-	return min_volt / 1000;
-}
-
-#define NO_SPLIT 0xff
-
-static const struct axp_regulator {
-	char *dt_name;
-	uint16_t min_volt;
-	uint16_t max_volt;
-	uint16_t step;
-	unsigned char split;
-	unsigned char volt_reg;
-	unsigned char switch_reg;
-	unsigned char switch_bit;
-} regulators[] = {
-	{"dcdc1", 1600, 3400, 100, NO_SPLIT, 0x20, 0x10, 0},
-	{"dcdc5",  800, 1840,  10,       32, 0x24, 0x10, 4},
-	{"dcdc6",  600, 1520,  10,       50, 0x25, 0x10, 5},
-	{"dldo1",  700, 3300, 100, NO_SPLIT, 0x15, 0x12, 3},
-	{"dldo2",  700, 4200, 100,       27, 0x16, 0x12, 4},
-	{"dldo3",  700, 3300, 100, NO_SPLIT, 0x17, 0x12, 5},
-	{"dldo4",  700, 3300, 100, NO_SPLIT, 0x18, 0x12, 6},
-	{"fldo1",  700, 1450,  50, NO_SPLIT, 0x1c, 0x13, 2},
-	{}
-};
-
-static int setup_regulator(const void *fdt, int node,
-			   const struct axp_regulator *reg)
+int axp_write(uint8_t reg, uint8_t val)
 {
-	int mvolt;
-	uint8_t regval;
-
-	if (!should_enable_regulator(fdt, node))
-		return -ENOENT;
-
-	mvolt = fdt_get_regulator_millivolt(fdt, node);
-	if (mvolt < reg->min_volt || mvolt > reg->max_volt)
-		return -EINVAL;
-
-	regval = (mvolt / reg->step) - (reg->min_volt / reg->step);
-	if (regval > reg->split)
-		regval = ((regval - reg->split) / 2) + reg->split;
-
-	axp_write(reg->volt_reg, regval);
-	if (reg->switch_reg < 0xff)
-		axp_setbits(reg->switch_reg, BIT(reg->switch_bit));
-
-	INFO("PMIC: AXP803: %s voltage: %d.%03dV\n", reg->dt_name,
-	     mvolt / 1000, mvolt % 1000);
-
-	return 0;
-}
-
-static void setup_axp803_rails(const void *fdt)
-{
-	int node;
-	bool dc1sw = false;
-
-	/* locate the PMIC DT node, bail out if not found */
-	node = fdt_node_offset_by_compatible(fdt, -1, "x-powers,axp803");
-	if (node < 0) {
-		WARN("BL31: PMIC: Cannot find AXP803 DT node, skipping initial setup.\n");
-		return;
-	}
-
-	if (fdt_getprop(fdt, node, "x-powers,drive-vbus-en", NULL)) {
-		axp_clrbits(0x8f, BIT(4));
-		axp_setbits(0x30, BIT(2));
-		INFO("PMIC: AXP803: Enabling DRIVEVBUS\n");
-	}
-
-	/* descend into the "regulators" subnode */
-	node = fdt_subnode_offset(fdt, node, "regulators");
-	if (node < 0) {
-		WARN("BL31: PMIC: Cannot find regulators subnode, skipping initial setup.\n");
-		return;
-	}
-
-	/* iterate over all regulators to find used ones */
-	for (node = fdt_first_subnode(fdt, node);
-	     node >= 0;
-	     node = fdt_next_subnode(fdt, node)) {
-		const struct axp_regulator *reg;
-		const char *name;
-		int length;
-
-		/* We only care if it's always on or referenced. */
-		if (!should_enable_regulator(fdt, node))
-			continue;
-
-		name = fdt_get_name(fdt, node, &length);
-		for (reg = regulators; reg->dt_name; reg++) {
-			if (!strncmp(name, reg->dt_name, length)) {
-				setup_regulator(fdt, node, reg);
-				break;
-			}
-		}
-
-		if (!strncmp(name, "dc1sw", length)) {
-			/* Delay DC1SW enablement to avoid overheating. */
-			dc1sw = true;
-			continue;
-		}
-	}
-	/*
-	 * If DLDO2 is enabled after DC1SW, the PMIC overheats and shuts
-	 * down. So always enable DC1SW as the very last regulator.
-	 */
-	if (dc1sw) {
-		INFO("PMIC: AXP803: Enabling DC1SW\n");
-		axp_setbits(0x12, BIT(7));
-	}
+	return rsb_write(AXP803_RT_ADDR, reg, val);
 }
 
 int sunxi_pmic_setup(uint16_t socid, const void *fdt)
@@ -290,11 +135,16 @@ int sunxi_pmic_setup(uint16_t socid, const void *fdt)
 
 	switch (socid) {
 	case SUNXI_SOC_H5:
+		NOTICE("PMIC: Assuming H5 reference regulator design\n");
+
 		pmic = REF_DESIGN_H5;
-		NOTICE("BL31: PMIC: Defaulting to PortL GPIO according to H5 reference design.\n");
+
 		break;
 	case SUNXI_SOC_A64:
 		pmic = GENERIC_A64;
+
+		INFO("PMIC: Probing AXP803 on RSB\n");
+
 		ret = sunxi_init_platform_r_twi(socid, true);
 		if (ret)
 			return ret;
@@ -304,20 +154,16 @@ int sunxi_pmic_setup(uint16_t socid, const void *fdt)
 			return ret;
 
 		pmic = AXP803_RSB;
-		NOTICE("BL31: PMIC: Detected AXP803 on RSB.\n");
-
-		if (fdt)
-			setup_axp803_rails(fdt);
+		axp_setup_regulators(fdt);
 
 		break;
 	default:
-		NOTICE("BL31: PMIC: No support for Allwinner %x SoC.\n", socid);
 		return -ENODEV;
 	}
 	return 0;
 }
 
-void __dead2 sunxi_power_down(void)
+void sunxi_power_down(void)
 {
 	switch (pmic) {
 	case GENERIC_H5:
@@ -355,16 +201,10 @@ void __dead2 sunxi_power_down(void)
 		/* (Re-)init RSB in case the rich OS has disabled it. */
 		sunxi_init_platform_r_twi(SUNXI_SOC_A64, true);
 		rsb_init();
-
-		/* Set "power disable control" bit */
-		axp_setbits(0x32, BIT(7));
+		axp_power_off();
 		break;
 	default:
 		break;
 	}
 
-	udelay(1000);
-	ERROR("PSCI: Cannot turn off system, halting.\n");
-	wfi();
-	panic();
 }

plat/allwinner/sun50i_h6/platform.mk

 #
-# Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+# Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
 #
 # SPDX-License-Identifier: BSD-3-Clause
 #
@@ -7,4 +7,4 @@
 # The differences between the platform are covered by the include files.
 include plat/allwinner/common/allwinner-common.mk
 
-PLAT_BL_COMMON_SOURCES	+=	drivers/mentor/i2c/mi2cv.c
+BL31_SOURCES		+=	drivers/mentor/i2c/mi2cv.c

plat/allwinner/sun50i_h6/sunxi_power.c

 /*
- * Copyright (c) 2017-2018, ARM Limited and Contributors. All rights reserved.
+ * Copyright (c) 2017-2019, ARM Limited and Contributors. All rights reserved.
  * Copyright (c) 2018, Icenowy Zheng <icenowy@aosc.io>
  *
  * SPDX-License-Identifier: BSD-3-Clause
@@ -21,27 +21,33 @@
 #define AXP805_ADDR	0x36
 #define AXP805_ID	0x03
 
-enum pmic_type {
-	NO_PMIC,
+static enum pmic_type {
+	UNKNOWN,
 	AXP805,
-};
-
-enum pmic_type pmic;
+} pmic;
 
 int axp_i2c_read(uint8_t chip, uint8_t reg, uint8_t *val)
 {
 	int ret;
 
 	ret = i2c_write(chip, 0, 0, &reg, 1);
+	if (ret == 0)
+		ret = i2c_read(chip, 0, 0, val, 1);
 	if (ret)
-		return ret;
+		ERROR("PMIC: Cannot read AXP805 register %02x\n", reg);
 
-	return i2c_read(chip, 0, 0, val, 1);
+	return ret;
 }
 
 int axp_i2c_write(uint8_t chip, uint8_t reg, uint8_t val)
 {
-	return i2c_write(chip, reg, 1, &val, 1);
+	int ret;
+
+	ret = i2c_write(chip, reg, 1, &val, 1);
+	if (ret)
+		ERROR("PMIC: Cannot write AXP805 register %02x\n", reg);
+
+	return ret;
 }
 
 static int axp805_probe(void)
@@ -49,21 +55,18 @@ static int axp805_probe(void)
 	int ret;
 	uint8_t val;
 
+	/* Switch the AXP805 to master/single-PMIC mode. */
 	ret = axp_i2c_write(AXP805_ADDR, 0xff, 0x0);
-	if (ret) {
-		ERROR("PMIC: Cannot put AXP805 to master mode.\n");
-		return -EPERM;
-	}
+	if (ret)
+		return ret;
 
 	ret = axp_i2c_read(AXP805_ADDR, AXP805_ID, &val);
+	if (ret)
+		return ret;
 
-	if (!ret && ((val & 0xcf) == 0x40))
-		NOTICE("PMIC: AXP805 detected\n");
-	else if (ret) {
-		ERROR("PMIC: Cannot communicate with AXP805.\n");
-		return -EPERM;
-	} else {
-		ERROR("PMIC: Non-AXP805 chip attached at AXP805's address.\n");
+	val &= 0xcf;
+	if (val != 0x40) {
+		ERROR("PMIC: Found unknown PMIC %02x\n", val);
 		return -EINVAL;
 	}
 
@@ -74,23 +77,25 @@ int sunxi_pmic_setup(uint16_t socid, const void *fdt)
 {
 	int ret;
 
-	sunxi_init_platform_r_twi(SUNXI_SOC_H6, false);
+	INFO("PMIC: Probing AXP805 on I2C\n");
+
+	ret = sunxi_init_platform_r_twi(SUNXI_SOC_H6, false);
+	if (ret)
+		return ret;
+
 	/* initialise mi2cv driver */
 	i2c_init((void *)SUNXI_R_I2C_BASE);
 
-	NOTICE("PMIC: Probing AXP805\n");
-	pmic = AXP805;
-
 	ret = axp805_probe();
 	if (ret)
-		pmic = NO_PMIC;
-	else
-		pmic = AXP805;
+		return ret;
+
+	pmic = AXP805;
 
 	return 0;
 }
 
-void __dead2 sunxi_power_down(void)
+void sunxi_power_down(void)
 {
 	uint8_t val;
 
@@ -106,9 +111,4 @@ void __dead2 sunxi_power_down(void)
 	default:
 		break;
 	}
-
-	udelay(1000);
-	ERROR("PSCI: Cannot communicate with PMIC, halting\n");
-	wfi();
-	panic();
 }