power: pmic: sunxi: add AXP313 SPL driver

On boards using the AXP313 PMIC, the DRAM rail is often not setup
correctly at reset time, so we have to program the PMIC very early in
the SPL, before running the DRAM initialisation.

Add a simple AXP313 PMIC driver that knows about DCDC2(CPU) and
DCDC3(DRAM), so that we can bump up the voltage before the DRAM init.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>

arch/arm/mach-sunxi/pmic_bus.c

@@ -22,6 +22,7 @@
 #define AXP209_I2C_ADDR			0x34
 
 #define AXP305_I2C_ADDR			0x36
+#define AXP313_I2C_ADDR			0x36
 
 #define AXP221_CHIP_ADDR		0x68
 
@@ -34,6 +35,8 @@ static int pmic_i2c_address(void)
 		return AXP152_I2C_ADDR;
 	if (IS_ENABLED(CONFIG_AXP305_POWER))
 		return AXP305_I2C_ADDR;
+	if (IS_ENABLED(CONFIG_AXP313_POWER))
+		return AXP313_I2C_ADDR;
 
 	/* Other AXP2xx and AXP8xx variants */
 	return AXP209_I2C_ADDR;

board/sunxi/board.c

@@ -569,7 +569,8 @@ void sunxi_board_init(void)
 
 #if defined CONFIG_AXP152_POWER || defined CONFIG_AXP209_POWER || \
 	defined CONFIG_AXP221_POWER || defined CONFIG_AXP305_POWER || \
-	defined CONFIG_AXP809_POWER || defined CONFIG_AXP818_POWER
+	defined CONFIG_AXP809_POWER || defined CONFIG_AXP818_POWER || \
+	defined CONFIG_AXP313_POWER
 	power_failed = axp_init();
 
 	if (IS_ENABLED(CONFIG_AXP_DISABLE_BOOT_ON_POWERON) && !power_failed) {

drivers/power/Kconfig

@@ -101,6 +101,15 @@ config AXP305_POWER
 	Select this to enable support for the axp305 pmic found on most
 	H616 boards.
 
+config AXP313_POWER
+	bool "axp313 pmic support"
+	depends on MACH_SUN50I_H616
+	select AXP_PMIC_BUS
+	select CMD_POWEROFF
+	---help---
+	Select this to enable support for the AXP313 PMIC found on some
+	H616 boards.
+
 config AXP809_POWER
 	bool "axp809 pmic support"
 	depends on MACH_SUN9I
@@ -143,9 +152,10 @@ config AXP_DCDC1_VOLT
 
 config AXP_DCDC2_VOLT
 	int "axp pmic dcdc2 voltage"
-	depends on AXP152_POWER || AXP209_POWER || AXP221_POWER || AXP809_POWER || AXP818_POWER
+	depends on AXP152_POWER || AXP209_POWER || AXP221_POWER || AXP809_POWER || AXP818_POWER || AXP313_POWER
 	default 900 if AXP818_POWER
 	default 1400 if AXP152_POWER || AXP209_POWER
+	default 1000 if AXP313_POWER
 	default 1200 if MACH_SUN6I
 	default 1100 if MACH_SUN8I
 	default 0 if MACH_SUN9I
@@ -158,13 +168,15 @@ config AXP_DCDC2_VOLT
 	On A80 boards dcdc2 powers the GPU and can be left off.
 	On A83T boards dcdc2 is used for VDD-CPUA(cluster 0) and should be 0.9V.
 	On R40 boards dcdc2 is VDD-CPU and should be 1.1V
+	On boards using the AXP313 it's often VDD-CPU.
 
 config AXP_DCDC3_VOLT
 	int "axp pmic dcdc3 voltage"
-	depends on AXP152_POWER || AXP209_POWER || AXP221_POWER || AXP809_POWER || AXP818_POWER
+	depends on AXP152_POWER || AXP209_POWER || AXP221_POWER || AXP809_POWER || AXP818_POWER || AXP313_POWER
 	default 900 if AXP809_POWER || AXP818_POWER
 	default 1500 if AXP152_POWER
 	default 1250 if AXP209_POWER
+	default 1100 if AXP313_POWER
 	default 1100 if MACH_SUN8I_R40
 	default 1200 if MACH_SUN6I || MACH_SUN8I
 	---help---
@@ -177,6 +189,7 @@ config AXP_DCDC3_VOLT
 	On A80 boards dcdc3 is used for VDD-CPUA(cluster 0) and should be 0.9V.
 	On A83T boards dcdc3 is used for VDD-CPUB(cluster 1) and should be 0.9V.
 	On R40 boards dcdc3 is VDD-SYS and VDD-GPU and should be 1.1V.
+	On boards using the AXP313 it's often VDD-DRAM and should be 1.1V for LPDDR4.
 
 config AXP_DCDC4_VOLT
 	int "axp pmic dcdc4 voltage"

drivers/power/Makefile

@@ -12,6 +12,7 @@ obj-$(CONFIG_AXP152_POWER)	+= axp152.o
 obj-$(CONFIG_AXP209_POWER)	+= axp209.o
 obj-$(CONFIG_AXP221_POWER)	+= axp221.o
 obj-$(CONFIG_AXP305_POWER)	+= axp305.o
+obj-$(CONFIG_AXP313_POWER)	+= axp313.o
 obj-$(CONFIG_AXP809_POWER)	+= axp809.o
 obj-$(CONFIG_AXP818_POWER)	+= axp818.o
 obj-$(CONFIG_EXYNOS_TMU)	+= exynos-tmu.o

drivers/power/axp313.c

@@ -0,0 +1,134 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * AXP313(a) driver
+ *
+ * (C) Copyright 2023 Arm Ltd.
+ *
+ * Based on axp305.c
+ * (C) Copyright 2020 Jernej Skrabec <jernej.skrabec@siol.net>
+ * (C) Copyright 2014 Hans de Goede <hdegoede@redhat.com>
+ * (C) Copyright 2013 Oliver Schinagl <oliver@schinagl.nl>
+ */
+
+#include <common.h>
+#include <command.h>
+#include <errno.h>
+#include <asm/arch/pmic_bus.h>
+#include <axp_pmic.h>
+
+enum axp313_reg {
+	AXP313_CHIP_VERSION	= 0x03,
+	AXP313_OUTPUT_CTRL	= 0x10,
+	AXP313_DCDC1_CTRL	= 0x13,
+	AXP313_SHUTDOWN		= 0x1a,
+};
+
+#define AXP313_CHIP_VERSION_MASK	0xcf
+#define AXP313_CHIP_VERSION_AXP1530	0x48
+#define AXP313_CHIP_VERSION_AXP313A	0x4b
+#define AXP313_CHIP_VERSION_AXP313B	0x4c
+
+#define AXP313_DCDC_SPLIT_OFFSET	71
+#define AXP313_DCDC_SPLIT_MVOLT		1200
+
+#define AXP313_POWEROFF			BIT(7)
+
+static u8 mvolt_to_cfg(int mvolt, int min, int max, int div)
+{
+	if (mvolt < min)
+		mvolt = min;
+	else if (mvolt > max)
+		mvolt = max;
+
+	return (mvolt - min) / div;
+}
+
+static int axp_set_dcdc(int dcdc_num, unsigned int mvolt)
+{
+	int ret;
+	u8 cfg, enable_mask = 1U << (dcdc_num - 1);
+	int volt_reg = AXP313_DCDC1_CTRL + dcdc_num - 1;
+	int max_mV;
+
+	switch (dcdc_num) {
+	case 1:
+	case 2:
+		max_mV	= 1540;
+		break;
+	case 3:
+		/*
+		 * The manual defines a different split point, but tests
+		 * show that it's the same 1200mV as for DCDC1/2.
+		 */
+		max_mV	= 1840;
+		break;
+	default:
+		return -EINVAL;
+	}
+
+	if (mvolt > AXP313_DCDC_SPLIT_MVOLT)
+		cfg = AXP313_DCDC_SPLIT_OFFSET + mvolt_to_cfg(mvolt,
+				AXP313_DCDC_SPLIT_MVOLT + 20, max_mV, 20);
+	else
+		cfg = mvolt_to_cfg(mvolt, 500, AXP313_DCDC_SPLIT_MVOLT, 10);
+
+	if (mvolt == 0)
+		return pmic_bus_clrbits(AXP313_OUTPUT_CTRL, enable_mask);
+
+	debug("DCDC%d: writing 0x%x to reg 0x%x\n", dcdc_num, cfg, volt_reg);
+	ret = pmic_bus_write(volt_reg, cfg);
+	if (ret)
+		return ret;
+
+	return pmic_bus_setbits(AXP313_OUTPUT_CTRL, enable_mask);
+}
+
+int axp_set_dcdc2(unsigned int mvolt)
+{
+	return axp_set_dcdc(2, mvolt);
+}
+
+int axp_set_dcdc3(unsigned int mvolt)
+{
+	return axp_set_dcdc(3, mvolt);
+}
+
+int axp_init(void)
+{
+	u8 axp_chip_id;
+	int ret;
+
+	ret = pmic_bus_init();
+	if (ret)
+		return ret;
+
+	ret = pmic_bus_read(AXP313_CHIP_VERSION, &axp_chip_id);
+	if (ret)
+		return ret;
+
+	axp_chip_id &= AXP313_CHIP_VERSION_MASK;
+	switch (axp_chip_id) {
+	case AXP313_CHIP_VERSION_AXP1530:
+	case AXP313_CHIP_VERSION_AXP313A:
+	case AXP313_CHIP_VERSION_AXP313B:
+		break;
+	default:
+		debug("unknown PMIC: 0x%x\n", axp_chip_id);
+		return -EINVAL;
+	}
+
+	return ret;
+}
+
+#if !CONFIG_IS_ENABLED(ARM_PSCI_FW) && !IS_ENABLED(CONFIG_SYSRESET_CMD_POWEROFF)
+int do_poweroff(struct cmd_tbl *cmdtp, int flag, int argc, char *const argv[])
+{
+	pmic_bus_write(AXP313_SHUTDOWN, AXP313_POWEROFF);
+
+	/* infinite loop during shutdown */
+	while (1) {}
+
+	/* not reached */
+	return 0;
+}
+#endif