regulator: spacemit: support SpacemiT P1 regulators

Add support for the regulators found in the SpacemiT P1 PMIC.  This
PMIC provides 6 buck converters and 12 LDO regulators.

The PMIC is implemented as a multi-function device.  These regulators
are probed based on this driver being named in a MFD cell in the simple
MFD I2C driver.

Signed-off-by: Alex Elder <elder@riscstar.com>
Link: https://patch.msgid.link/20250825172057.163883-4-elder@riscstar.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/regulator/Kconfig

@@ -1443,6 +1443,19 @@ config REGULATOR_SLG51000
 	  The SLG51000 is seven compact and customizable low dropout
 	  regulators.
 
+config REGULATOR_SPACEMIT_P1
+	tristate "SpacemiT P1 regulators"
+	depends on ARCH_SPACEMIT || COMPILE_TEST
+	depends on I2C
+	select MFD_SPACEMIT_P1
+	default ARCH_SPACEMIT
+	help
+	  Enable support for regulators implemented by the SpacemiT P1
+	  power controller.  The P1 implements 6 high-efficiency buck
+	  converters and 12 programmable LDO regulators.  To compile this
+	  driver as a module, choose M here.  The module will be called
+	  "spacemit-pmic".
+
 config REGULATOR_STM32_BOOSTER
 	tristate "STMicroelectronics STM32 BOOSTER"
 	depends on ARCH_STM32 || COMPILE_TEST

drivers/regulator/Makefile

@@ -167,6 +167,7 @@ obj-$(CONFIG_REGULATOR_S5M8767) += s5m8767.o
 obj-$(CONFIG_REGULATOR_SC2731) += sc2731-regulator.o
 obj-$(CONFIG_REGULATOR_SKY81452) += sky81452-regulator.o
 obj-$(CONFIG_REGULATOR_SLG51000) += slg51000-regulator.o
+obj-$(CONFIG_REGULATOR_SPACEMIT_P1) += spacemit-p1.o
 obj-$(CONFIG_REGULATOR_STM32_BOOSTER) += stm32-booster.o
 obj-$(CONFIG_REGULATOR_STM32_VREFBUF) += stm32-vrefbuf.o
 obj-$(CONFIG_REGULATOR_STM32_PWR) += stm32-pwr.o

drivers/regulator/spacemit-p1.c

@@ -0,0 +1,157 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Driver for regulators found in the SpacemiT P1 PMIC
+ *
+ * Copyright (C) 2025 by RISCstar Solutions Corporation.  All rights reserved.
+ * Derived from code from SpacemiT.
+ *	Copyright (c) 2023, SPACEMIT Co., Ltd
+ */
+
+#include <linux/array_size.h>
+#include <linux/bits.h>
+#include <linux/device.h>
+#include <linux/linear_range.h>
+#include <linux/module.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/driver.h>
+
+#define MOD_NAME	"spacemit-p1-regulator"
+
+enum p1_regulator_id {
+	P1_BUCK1,
+	P1_BUCK2,
+	P1_BUCK3,
+	P1_BUCK4,
+	P1_BUCK5,
+	P1_BUCK6,
+
+	P1_ALDO1,
+	P1_ALDO2,
+	P1_ALDO3,
+	P1_ALDO4,
+
+	P1_DLDO1,
+	P1_DLDO2,
+	P1_DLDO3,
+	P1_DLDO4,
+	P1_DLDO5,
+	P1_DLDO6,
+	P1_DLDO7,
+};
+
+static const struct regulator_ops p1_regulator_ops = {
+	.list_voltage		= regulator_list_voltage_linear_range,
+	.get_voltage_sel	= regulator_get_voltage_sel_regmap,
+	.set_voltage_sel	= regulator_set_voltage_sel_regmap,
+	.set_voltage_time_sel   = regulator_set_voltage_time_sel,
+	.enable			= regulator_enable_regmap,
+	.disable		= regulator_disable_regmap,
+	.is_enabled		= regulator_is_enabled_regmap,
+};
+
+/* Selector value 255 can be used to disable the buck converter on sleep */
+static const struct linear_range p1_buck_ranges[] = {
+	REGULATOR_LINEAR_RANGE(500000, 0, 170, 5000),
+	REGULATOR_LINEAR_RANGE(1375000, 171, 254, 25000),
+};
+
+/* Selector value 0 can be used for suspend */
+static const struct linear_range p1_ldo_ranges[] = {
+	REGULATOR_LINEAR_RANGE(500000, 11, 127, 25000),
+};
+
+/* These define the voltage selector field for buck and LDO regulators */
+#define BUCK_MASK		GENMASK(7, 0)
+#define LDO_MASK		GENMASK(6, 0)
+
+#define P1_ID(_TYPE, _n)	P1_ ## _TYPE ## _n
+#define P1_ENABLE_REG(_off, _n)	((_off) + 3 * ((_n) - 1))
+
+#define P1_REG_DESC(_TYPE, _type, _n, _s, _off, _mask, _nv, _ranges)	\
+	{								\
+		.name			= #_type #_n,			\
+		.supply_name		= _s,				\
+		.of_match		= of_match_ptr(#_type #_n),	\
+		.regulators_node	= of_match_ptr("regulators"),	\
+		.id			= P1_ID(_TYPE, _n),		\
+		.n_voltages		= _nv,				\
+		.ops			= &p1_regulator_ops,		\
+		.owner			= THIS_MODULE,			\
+		.linear_ranges		= _ranges,			\
+		.n_linear_ranges	= ARRAY_SIZE(_ranges),		\
+		.vsel_reg		= P1_ENABLE_REG(_off, _n) + 1,	\
+		.vsel_mask		= _mask,			\
+		.enable_reg		= P1_ENABLE_REG(_off, _n),	\
+		.enable_mask		= BIT(0),			\
+	}
+
+#define P1_BUCK_DESC(_n) \
+	P1_REG_DESC(BUCK, buck, _n, "vcc", 0x47, BUCK_MASK, 254, p1_buck_ranges)
+
+#define P1_ALDO_DESC(_n) \
+	P1_REG_DESC(ALDO, aldo, _n, "vcc", 0x5b, LDO_MASK, 117, p1_ldo_ranges)
+
+#define P1_DLDO_DESC(_n) \
+	P1_REG_DESC(DLDO, dldo, _n, "buck5", 0x67, LDO_MASK, 117, p1_ldo_ranges)
+
+static const struct regulator_desc p1_regulator_desc[] = {
+	P1_BUCK_DESC(1),
+	P1_BUCK_DESC(2),
+	P1_BUCK_DESC(3),
+	P1_BUCK_DESC(4),
+	P1_BUCK_DESC(5),
+	P1_BUCK_DESC(6),
+
+	P1_ALDO_DESC(1),
+	P1_ALDO_DESC(2),
+	P1_ALDO_DESC(3),
+	P1_ALDO_DESC(4),
+
+	P1_DLDO_DESC(1),
+	P1_DLDO_DESC(2),
+	P1_DLDO_DESC(3),
+	P1_DLDO_DESC(4),
+	P1_DLDO_DESC(5),
+	P1_DLDO_DESC(6),
+	P1_DLDO_DESC(7),
+};
+
+static int p1_regulator_probe(struct platform_device *pdev)
+{
+	struct regulator_config config = { };
+	struct device *dev = &pdev->dev;
+	u32 i;
+
+	/*
+	 * The parent device (PMIC) owns the regmap.  Since we don't
+	 * provide one in the config structure, that one will be used.
+	 */
+	config.dev = dev->parent;
+
+	for (i = 0; i < ARRAY_SIZE(p1_regulator_desc); i++) {
+		const struct regulator_desc *desc = &p1_regulator_desc[i];
+		struct regulator_dev *rdev;
+
+		rdev = devm_regulator_register(dev, desc, &config);
+		if (IS_ERR(rdev))
+			return dev_err_probe(dev, PTR_ERR(rdev),
+					     "error registering regulator %s\n",
+					     desc->name);
+	}
+
+	return 0;
+}
+
+static struct platform_driver p1_regulator_driver = {
+	.probe = p1_regulator_probe,
+	.driver = {
+		.name = MOD_NAME,
+	},
+};
+
+module_platform_driver(p1_regulator_driver);
+
+MODULE_DESCRIPTION("SpacemiT P1 regulator driver");
+MODULE_LICENSE("GPL");
+MODULE_ALIAS("platform:" MOD_NAME);