diff --git a/plat/allwinner/common/include/sunxi_private.h b/plat/allwinner/common/include/sunxi_private.h
index 54cc27e..6c9c509 100644
--- a/plat/allwinner/common/include/sunxi_private.h
+++ b/plat/allwinner/common/include/sunxi_private.h
@@ -19,5 +19,6 @@
 
 uint16_t sunxi_read_soc_id(void);
 void sunxi_set_gpio_out(char port, int pin, bool level_high);
+int sunxi_init_platform_r_twi(uint16_t socid, bool use_rsb);
 
 #endif /* SUNXI_PRIVATE_H */
diff --git a/plat/allwinner/common/sunxi_common.c b/plat/allwinner/common/sunxi_common.c
index 88156b5..a39c149 100644
--- a/plat/allwinner/common/sunxi_common.c
+++ b/plat/allwinner/common/sunxi_common.c
@@ -4,6 +4,8 @@
  * SPDX-License-Identifier: BSD-3-Clause
  */
 
+#include <debug.h>
+#include <errno.h>
 #include <mmio.h>
 #include <platform.h>
 #include <platform_def.h>
@@ -100,3 +102,58 @@
 			   0x7 << ((pin % 8) * 4),
 			   0x1 << ((pin % 8) * 4));
 }
+
+int sunxi_init_platform_r_twi(uint16_t socid, bool use_rsb)
+{
+	uint32_t pin_func = 0x77;
+	uint32_t device_bit;
+	unsigned int reset_offset = 0xb0;
+
+	switch (socid) {
+	case SUNXI_SOC_H5:
+		if (use_rsb)
+			return -ENODEV;
+		pin_func = 0x22;
+		device_bit = BIT(6);
+		break;
+	case SUNXI_SOC_H6:
+		if (use_rsb)
+			return -ENODEV;
+		pin_func = 0x33;
+		device_bit = BIT(16);
+		reset_offset = 0x19c;
+		break;
+	case SUNXI_SOC_A64:
+		pin_func = use_rsb ? 0x22 : 0x33;
+		device_bit = use_rsb ? BIT(3) : BIT(6);
+		break;
+	default:
+		INFO("R_I2C/RSB on Allwinner 0x%x SoC not supported\n", socid);
+		return -ENODEV;
+	}
+
+	/* un-gate R_PIO clock */
+	if (socid != SUNXI_SOC_H6)
+		mmio_setbits_32(SUNXI_R_PRCM_BASE + 0x28, BIT(0));
+
+	/* switch pins PL0 and PL1 to the desired function */
+	mmio_clrsetbits_32(SUNXI_R_PIO_BASE + 0x00, 0xffU, pin_func);
+
+	/* level 2 drive strength */
+	mmio_clrsetbits_32(SUNXI_R_PIO_BASE + 0x14, 0x0fU, 0xaU);
+
+	/* 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));
+
+	return 0;
+}
diff --git a/plat/allwinner/sun50i_h6/sunxi_power.c b/plat/allwinner/sun50i_h6/sunxi_power.c
index 8e29310..0a62eaa 100644
--- a/plat/allwinner/sun50i_h6/sunxi_power.c
+++ b/plat/allwinner/sun50i_h6/sunxi_power.c
@@ -12,6 +12,7 @@
 #include <mmio.h>
 #include <mentor/mi2cv.h>
 #include <string.h>
+#include <sunxi_def.h>
 #include <sunxi_mmap.h>
 #include <sunxi_private.h>
 
@@ -25,36 +26,6 @@
 
 enum pmic_type pmic;
 
-static int sunxi_init_r_i2c(void)
-{
-	uint32_t reg;
-
-	/* switch pins PL0 and PL1 to I2C */
-	reg = mmio_read_32(SUNXI_R_PIO_BASE + 0x00);
-	mmio_write_32(SUNXI_R_PIO_BASE + 0x00, (reg & ~0xff) | 0x33);
-
-	/* level 2 drive strength */
-	reg = mmio_read_32(SUNXI_R_PIO_BASE + 0x14);
-	mmio_write_32(SUNXI_R_PIO_BASE + 0x14, (reg & ~0x0f) | 0xa);
-
-	/* set both ports to pull-up */
-	reg = mmio_read_32(SUNXI_R_PIO_BASE + 0x1c);
-	mmio_write_32(SUNXI_R_PIO_BASE + 0x1c, (reg & ~0x0f) | 0x5);
-
-	/* assert & de-assert reset of R_I2C */
-	reg = mmio_read_32(SUNXI_R_PRCM_BASE + 0x19c);
-	mmio_write_32(SUNXI_R_PRCM_BASE + 0x19c, reg & ~BIT(16));
-	mmio_write_32(SUNXI_R_PRCM_BASE + 0x19c, reg | BIT(16));
-
-	/* un-gate R_I2C clock */
-	mmio_write_32(SUNXI_R_PRCM_BASE + 0x19c, reg | BIT(16) | BIT(0));
-
-	/* call mi2cv driver */
-	i2c_init((void *)SUNXI_R_I2C_BASE);
-
-	return 0;
-}
-
 int axp_i2c_read(uint8_t chip, uint8_t reg, uint8_t *val)
 {
 	int ret;
@@ -101,7 +72,9 @@
 {
 	int ret;
 
-	sunxi_init_r_i2c();
+	sunxi_init_platform_r_twi(SUNXI_SOC_H6, false);
+	/* initialise mi2cv driver */
+	i2c_init((void *)SUNXI_R_I2C_BASE);
 
 	NOTICE("PMIC: Probing AXP805\n");
 	pmic = AXP805;
@@ -121,7 +94,10 @@
 
 	switch (pmic) {
 	case AXP805:
-		sunxi_init_r_i2c();
+		/* Re-initialise after rich OS might have used it. */
+		sunxi_init_platform_r_twi(SUNXI_SOC_H6, false);
+		/* initialise mi2cv driver */
+		i2c_init((void *)SUNXI_R_I2C_BASE);
 		axp_i2c_read(AXP805_ADDR, 0x32, &val);
 		axp_i2c_write(AXP805_ADDR, 0x32, val | 0x80);
 		break;