mfd: Add driver for Marvell 88PM886 PMIC

Marvell 88PM886 is a PMIC which provides various functions such as
onkey, battery, charger and regulators. It is found for instance in the
samsung,coreprimevelte smartphone with which this was tested. Implement
basic support to allow for the use of regulators and onkey.

Signed-off-by: Karel Balej <balejk@matfyz.cz>
Link: https://lore.kernel.org/r/20240531175109.15599-3-balejk@matfyz.cz
Signed-off-by: Lee Jones <lee@kernel.org>

drivers/mfd/88pm886.c

@@ -0,0 +1,148 @@
+// SPDX-License-Identifier: GPL-2.0-only
+#include <linux/i2c.h>
+#include <linux/mfd/core.h>
+#include <linux/module.h>
+#include <linux/notifier.h>
+#include <linux/of.h>
+#include <linux/platform_device.h>
+#include <linux/reboot.h>
+#include <linux/regmap.h>
+
+#include <linux/mfd/88pm886.h>
+
+static const struct regmap_config pm886_regmap_config = {
+	.reg_bits = 8,
+	.val_bits = 8,
+	.max_register = PM886_REG_RTC_SPARE6,
+};
+
+static struct regmap_irq pm886_regmap_irqs[] = {
+	REGMAP_IRQ_REG(PM886_IRQ_ONKEY, 0, PM886_INT_ENA1_ONKEY),
+};
+
+static struct regmap_irq_chip pm886_regmap_irq_chip = {
+	.name = "88pm886",
+	.irqs = pm886_regmap_irqs,
+	.num_irqs = ARRAY_SIZE(pm886_regmap_irqs),
+	.num_regs = 4,
+	.status_base = PM886_REG_INT_STATUS1,
+	.ack_base = PM886_REG_INT_STATUS1,
+	.unmask_base = PM886_REG_INT_ENA_1,
+};
+
+static struct resource pm886_onkey_resources[] = {
+	DEFINE_RES_IRQ_NAMED(PM886_IRQ_ONKEY, "88pm886-onkey"),
+};
+
+static struct mfd_cell pm886_devs[] = {
+	MFD_CELL_RES("88pm886-onkey", pm886_onkey_resources),
+	MFD_CELL_NAME("88pm886-regulator"),
+};
+
+static int pm886_power_off_handler(struct sys_off_data *sys_off_data)
+{
+	struct pm886_chip *chip = sys_off_data->cb_data;
+	struct regmap *regmap = chip->regmap;
+	struct device *dev = &chip->client->dev;
+	int err;
+
+	err = regmap_update_bits(regmap, PM886_REG_MISC_CONFIG1, PM886_SW_PDOWN, PM886_SW_PDOWN);
+	if (err) {
+		dev_err(dev, "Failed to power off the device: %d\n", err);
+		return NOTIFY_BAD;
+	}
+	return NOTIFY_DONE;
+}
+
+static int pm886_setup_irq(struct pm886_chip *chip,
+		struct regmap_irq_chip_data **irq_data)
+{
+	struct regmap *regmap = chip->regmap;
+	struct device *dev = &chip->client->dev;
+	int err;
+
+	/* Set interrupt clearing mode to clear on write. */
+	err = regmap_update_bits(regmap, PM886_REG_MISC_CONFIG2,
+			PM886_INT_INV | PM886_INT_CLEAR | PM886_INT_MASK_MODE,
+			PM886_INT_WC);
+	if (err) {
+		dev_err(dev, "Failed to set interrupt clearing mode: %d\n", err);
+		return err;
+	}
+
+	err = devm_regmap_add_irq_chip(dev, regmap, chip->client->irq,
+					IRQF_ONESHOT, 0, &pm886_regmap_irq_chip,
+					irq_data);
+	if (err) {
+		dev_err(dev, "Failed to request IRQ: %d\n", err);
+		return err;
+	}
+
+	return 0;
+}
+
+static int pm886_probe(struct i2c_client *client)
+{
+	struct regmap_irq_chip_data *irq_data;
+	struct device *dev = &client->dev;
+	struct pm886_chip *chip;
+	struct regmap *regmap;
+	unsigned int chip_id;
+	int err;
+
+	chip = devm_kzalloc(dev, sizeof(*chip), GFP_KERNEL);
+	if (!chip)
+		return -ENOMEM;
+
+	chip->client = client;
+	chip->chip_id = (uintptr_t)device_get_match_data(dev);
+	i2c_set_clientdata(client, chip);
+
+	regmap = devm_regmap_init_i2c(client, &pm886_regmap_config);
+	if (IS_ERR(regmap))
+		return dev_err_probe(dev, PTR_ERR(regmap), "Failed to initialize regmap\n");
+	chip->regmap = regmap;
+
+	err = regmap_read(regmap, PM886_REG_ID, &chip_id);
+	if (err)
+		return dev_err_probe(dev, err, "Failed to read chip ID\n");
+
+	if (chip->chip_id != chip_id)
+		return dev_err_probe(dev, -EINVAL, "Unsupported chip: 0x%x\n", chip_id);
+
+	err = pm886_setup_irq(chip, &irq_data);
+	if (err)
+		return err;
+
+	err = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE, pm886_devs, ARRAY_SIZE(pm886_devs),
+				NULL, 0, regmap_irq_get_domain(irq_data));
+	if (err)
+		return dev_err_probe(dev, err, "Failed to add devices\n");
+
+	err = devm_register_power_off_handler(dev, pm886_power_off_handler, chip);
+	if (err)
+		return dev_err_probe(dev, err, "Failed to register power off handler\n");
+
+	device_init_wakeup(dev, device_property_read_bool(dev, "wakeup-source"));
+
+	return 0;
+}
+
+static const struct of_device_id pm886_of_match[] = {
+	{ .compatible = "marvell,88pm886-a1", .data = (void *)PM886_A1_CHIP_ID },
+	{ }
+};
+MODULE_DEVICE_TABLE(of, pm886_of_match);
+
+static struct i2c_driver pm886_i2c_driver = {
+	.driver = {
+		.name = "88pm886",
+		.of_match_table = pm886_of_match,
+	},
+	.probe = pm886_probe,
+};
+module_i2c_driver(pm886_i2c_driver);
+
+MODULE_DESCRIPTION("Marvell 88PM886 PMIC driver");
+MODULE_AUTHOR("Karel Balej <balejk@matfyz.cz>");
+MODULE_LICENSE("GPL");

drivers/mfd/Kconfig

@@ -794,6 +794,18 @@ config MFD_88PM860X
 	  select individual components like voltage regulators, RTC and
 	  battery-charger under the corresponding menus.
 
+config MFD_88PM886_PMIC
+	bool "Marvell 88PM886 PMIC"
+	depends on I2C=y
+	depends on OF
+	select REGMAP_I2C
+	select REGMAP_IRQ
+	select MFD_CORE
+	help
+	  This enables support for Marvell 88PM886 Power Management IC.
+	  This includes the I2C driver and the core APIs _only_, you have to
+	  select individual components like onkey under the corresponding menus.
+
 config MFD_MAX14577
 	tristate "Maxim Semiconductor MAX14577/77836 MUIC + Charger Support"
 	depends on I2C

drivers/mfd/Makefile

@@ -7,6 +7,7 @@
 obj-$(CONFIG_MFD_88PM860X)	+= 88pm860x.o
 obj-$(CONFIG_MFD_88PM800)	+= 88pm800.o 88pm80x.o
 obj-$(CONFIG_MFD_88PM805)	+= 88pm805.o 88pm80x.o
+obj-$(CONFIG_MFD_88PM886_PMIC)	+= 88pm886.o
 obj-$(CONFIG_MFD_ACT8945A)	+= act8945a.o
 obj-$(CONFIG_MFD_SM501)		+= sm501.o
 obj-$(CONFIG_ARCH_BCM2835)	+= bcm2835-pm.o

include/linux/mfd/88pm886.h

@@ -0,0 +1,69 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __MFD_88PM886_H
+#define __MFD_88PM886_H
+
+#include <linux/i2c.h>
+#include <linux/regmap.h>
+
+#define PM886_A1_CHIP_ID		0xa1
+
+#define PM886_IRQ_ONKEY			0
+
+#define PM886_PAGE_OFFSET_REGULATORS	1
+
+#define PM886_REG_ID			0x00
+
+#define PM886_REG_STATUS1		0x01
+#define PM886_ONKEY_STS1		BIT(0)
+
+#define PM886_REG_INT_STATUS1		0x05
+
+#define PM886_REG_INT_ENA_1		0x0a
+#define PM886_INT_ENA1_ONKEY		BIT(0)
+
+#define PM886_REG_MISC_CONFIG1		0x14
+#define PM886_SW_PDOWN			BIT(5)
+
+#define PM886_REG_MISC_CONFIG2		0x15
+#define PM886_INT_INV			BIT(0)
+#define PM886_INT_CLEAR			BIT(1)
+#define PM886_INT_RC			0x00
+#define PM886_INT_WC			BIT(1)
+#define PM886_INT_MASK_MODE		BIT(2)
+
+#define PM886_REG_RTC_SPARE6		0xef
+
+#define PM886_REG_BUCK_EN		0x08
+#define PM886_REG_LDO_EN1		0x09
+#define PM886_REG_LDO_EN2		0x0a
+#define PM886_REG_LDO1_VOUT		0x20
+#define PM886_REG_LDO2_VOUT		0x26
+#define PM886_REG_LDO3_VOUT		0x2c
+#define PM886_REG_LDO4_VOUT		0x32
+#define PM886_REG_LDO5_VOUT		0x38
+#define PM886_REG_LDO6_VOUT		0x3e
+#define PM886_REG_LDO7_VOUT		0x44
+#define PM886_REG_LDO8_VOUT		0x4a
+#define PM886_REG_LDO9_VOUT		0x50
+#define PM886_REG_LDO10_VOUT		0x56
+#define PM886_REG_LDO11_VOUT		0x5c
+#define PM886_REG_LDO12_VOUT		0x62
+#define PM886_REG_LDO13_VOUT		0x68
+#define PM886_REG_LDO14_VOUT		0x6e
+#define PM886_REG_LDO15_VOUT		0x74
+#define PM886_REG_LDO16_VOUT		0x7a
+#define PM886_REG_BUCK1_VOUT		0xa5
+#define PM886_REG_BUCK2_VOUT		0xb3
+#define PM886_REG_BUCK3_VOUT		0xc1
+#define PM886_REG_BUCK4_VOUT		0xcf
+#define PM886_REG_BUCK5_VOUT		0xdd
+
+#define PM886_LDO_VSEL_MASK		0x0f
+#define PM886_BUCK_VSEL_MASK		0x7f
+
+struct pm886_chip {
+	struct i2c_client *client;
+	unsigned int chip_id;
+	struct regmap *regmap;
+};
+#endif /* __MFD_88PM886_H */