mfd: axp20x: add mfd axp20x driver

This commit ports the axp20x driver from linux kernel code. Structures
not applicable for barebox are being dropped.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
Signed-off-by: Johannes Zink <j.zink@pengutronix.de>
Link: https://lore.barebox.org/20220830080911.440884-1-j.zink@pengutronix.de
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

4 files changed, 440 insertions, 0 deletions

diff --git a/drivers/mfd/Kconfig b/drivers/mfd/Kconfig
index 6c6b65dacf..5fd1a0aaa8 100644
--- a/drivers/mfd/Kconfig
+++ b/drivers/mfd/Kconfig
@@ -117,4 +117,12 @@ config MFD_RK808
 	  This driver provides common support for accessing the device
 	  through I2C interface.
 
+config MFD_AXP20X_I2C
+	tristate "X-Powers AXP series PMICs with I2C"
+	depends on I2C && OFDEVICE
+	help
+	  If you say Y here you get support for the X-Powers AXP series power
+	  management ICs (PMICs) controlled with I2C.
+	  This driver currently only provide a character device in /dev.
+
 endmenu
diff --git a/drivers/mfd/Makefile b/drivers/mfd/Makefile
index 7b5d0398d1..a3cb90e883 100644
--- a/drivers/mfd/Makefile
+++ b/drivers/mfd/Makefile
@@ -22,3 +22,4 @@ obj-$(CONFIG_SMSC_SUPERIO)	+= smsc-superio.o
 obj-$(CONFIG_MFD_STM32_TIMERS)	+= stm32-timers.o
 obj-$(CONFIG_MFD_ATMEL_FLEXCOM)	+= atmel-flexcom.o
 obj-$(CONFIG_MFD_RK808)		+= rk808.o
+obj-$(CONFIG_MFD_AXP20X_I2C)	+= axp20x-i2c.o axp20x.o
diff --git a/drivers/mfd/axp20x-i2c.c b/drivers/mfd/axp20x-i2c.c
new file mode 100644
index 0000000000..d0f6a0f394
--- /dev/null
+++ b/drivers/mfd/axp20x-i2c.c
@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * I2C driver for the X-Powers' Power Management ICs
+ *
+ * AXP20x typically comprises an adaptive USB-Compatible PWM charger, BUCK DC-DC
+ * converters, LDOs, multiple 12-bit ADCs of voltage, current and temperature
+ * as well as configurable GPIOs.
+ *
+ * This driver supports the I2C variants.
+ *
+ * Copyright (C) 2014 Carlo Caione
+ *
+ * Author: Carlo Caione <carlo@caione.org>
+ */
+
+#include <common.h>
+#include <of.h>
+#include <linux/err.h>
+#include <i2c/i2c.h>
+#include <module.h>
+#include <linux/mfd/axp20x.h>
+#include <regmap.h>
+
+static int axp20x_i2c_probe(struct device_d *dev)
+{
+	struct i2c_client *client = to_i2c_client(dev);
+	struct axp20x_dev *axp20x;
+	int ret;
+
+	axp20x = xzalloc(sizeof(*axp20x));
+
+	axp20x->dev = dev;
+
+	ret = axp20x_match_device(axp20x);
+	if (ret)
+		return ret;
+
+	axp20x->regmap = regmap_init_i2c(client, axp20x->regmap_cfg);
+	if (IS_ERR(axp20x->regmap))
+		return dev_err_probe(dev, PTR_ERR(axp20x->regmap),
+				     "regmap init failed\n");
+
+	ret = axp20x_device_probe(axp20x);
+	if (ret)
+		return ret;
+
+	return regmap_register_cdev(axp20x->regmap, NULL);
+}
+
+static const struct of_device_id axp20x_i2c_of_match[] = {
+	{ .compatible = "x-powers,axp152", .data = (void *)AXP152_ID },
+	{ .compatible = "x-powers,axp202", .data = (void *)AXP202_ID },
+	{ .compatible = "x-powers,axp209", .data = (void *)AXP209_ID },
+	{ .compatible = "x-powers,axp221", .data = (void *)AXP221_ID },
+	{ .compatible = "x-powers,axp223", .data = (void *)AXP223_ID },
+	{ .compatible = "x-powers,axp803", .data = (void *)AXP803_ID },
+	{ .compatible = "x-powers,axp806", .data = (void *)AXP806_ID },
+	{ },
+};
+
+static struct driver_d axp20x_i2c_driver = {
+	.name		= "axp20x-i2c",
+	.probe		= axp20x_i2c_probe,
+	.of_compatible	= DRV_OF_COMPAT(axp20x_i2c_of_match),
+};
+
+coredevice_i2c_driver(axp20x_i2c_driver);
+
+MODULE_DESCRIPTION("PMIC MFD I2C driver for AXP20X");
+MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
+MODULE_LICENSE("GPL");
diff --git a/drivers/mfd/axp20x.c b/drivers/mfd/axp20x.c
new file mode 100644
index 0000000000..da1e8ce35a
--- /dev/null
+++ b/drivers/mfd/axp20x.c
@@ -0,0 +1,360 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * MFD core driver for the X-Powers' Power Management ICs
+ *
+ * AXP20x typically comprises an adaptive USB-Compatible PWM charger, BUCK DC-DC
+ * converters, LDOs, multiple 12-bit ADCs of voltage, current and temperature
+ * as well as configurable GPIOs.
+ *
+ * This file contains the interface independent core functions.
+ *
+ * Copyright (C) 2014 Carlo Caione
+ *
+ * Author: Carlo Caione <carlo@caione.org>
+ */
+
+#include <common.h>
+#include <linux/bitops.h>
+#include <clock.h>
+#include <linux/err.h>
+#include <linux/kernel.h>
+#include <linux/mfd/axp20x.h>
+#include <linux/mfd/core.h>
+#include <module.h>
+#include <of.h>
+#include <of_device.h>
+#include <regmap.h>
+#include <regulator.h>
+
+#define AXP20X_OFF	BIT(7)
+
+#define AXP806_REG_ADDR_EXT_ADDR_MASTER_MODE	0
+#define AXP806_REG_ADDR_EXT_ADDR_SLAVE_MODE	BIT(4)
+
+static const char * const axp20x_model_names[] = {
+	"AXP152",
+	"AXP202",
+	"AXP209",
+	"AXP221",
+	"AXP223",
+	"AXP288",
+	"AXP803",
+	"AXP806",
+	"AXP809",
+	"AXP813",
+};
+
+static const struct regmap_config axp152_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.max_register	= AXP152_PWM1_DUTY_CYCLE,
+};
+
+static const struct regmap_config axp20x_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.max_register	= AXP20X_OCV(AXP20X_OCV_MAX),
+};
+
+static const struct regmap_config axp22x_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.max_register	= AXP22X_BATLOW_THRES1,
+};
+
+static const struct regmap_config axp288_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.max_register	= AXP288_FG_TUNE5,
+};
+
+static const struct regmap_config axp806_regmap_config = {
+	.reg_bits	= 8,
+	.val_bits	= 8,
+	.max_register	= AXP806_REG_ADDR_EXT,
+};
+
+static const struct mfd_cell axp20x_cells[] = {
+	{
+		.name		= "axp20x-gpio",
+		/* .of_compatible	= "x-powers,axp209-gpio", */
+	}, {
+		.name		= "axp20x-pek",
+	}, {
+		.name		= "axp20x-regulator",
+	}, {
+		.name		= "axp20x-adc",
+		/* .of_compatible	= "x-powers,axp209-adc", */
+	}, {
+		.name		= "axp20x-battery-power-supply",
+		/* .of_compatible	= "x-powers,axp209-battery-power-supply", */
+	}, {
+		.name		= "axp20x-ac-power-supply",
+		/* .of_compatible	= "x-powers,axp202-ac-power-supply", */
+	}, {
+		.name		= "axp20x-usb-power-supply",
+		/* .of_compatible	= "x-powers,axp202-usb-power-supply", */
+	},
+};
+
+static const struct mfd_cell axp221_cells[] = {
+	{
+		.name		= "axp221-pek",
+	}, {
+		.name		= "axp20x-regulator",
+	}, {
+		.name		= "axp22x-adc",
+		/* .of_compatible	= "x-powers,axp221-adc", */
+	}, {
+		.name		= "axp20x-ac-power-supply",
+		/* .of_compatible	= "x-powers,axp221-ac-power-supply", */
+	}, {
+		.name		= "axp20x-battery-power-supply",
+		/* .of_compatible	= "x-powers,axp221-battery-power-supply", */
+	}, {
+		.name		= "axp20x-usb-power-supply",
+		/* .of_compatible	= "x-powers,axp221-usb-power-supply", */
+	},
+};
+
+static const struct mfd_cell axp223_cells[] = {
+	{
+		.name		= "axp221-pek",
+	}, {
+		.name		= "axp22x-adc",
+		/* .of_compatible	= "x-powers,axp221-adc", */
+	}, {
+		.name		= "axp20x-battery-power-supply",
+		/* .of_compatible	= "x-powers,axp221-battery-power-supply", */
+	}, {
+		.name		= "axp20x-regulator",
+	}, {
+		.name		= "axp20x-ac-power-supply",
+		/* .of_compatible	= "x-powers,axp221-ac-power-supply", */
+	}, {
+		.name		= "axp20x-usb-power-supply",
+		/* .of_compatible	= "x-powers,axp223-usb-power-supply", */
+	},
+};
+
+static const struct mfd_cell axp152_cells[] = {
+	{
+		.name		= "axp20x-pek",
+	},
+};
+
+static const struct mfd_cell axp288_cells[] = {
+	{
+		.name		= "axp288_adc",
+	}, {
+		.name		= "axp288_extcon",
+	}, {
+		.name		= "axp288_charger",
+	}, {
+		.name		= "axp221-pek",
+	}, {
+		.name		= "axp288_pmic_acpi",
+	},
+};
+
+static const struct mfd_cell axp803_cells[] = {
+	{
+		.name		= "axp221-pek",
+	}, {
+		.name		= "axp20x-gpio",
+		/* .of_compatible	= "x-powers,axp813-gpio", */
+	}, {
+		.name		= "axp813-adc",
+		/* .of_compatible	= "x-powers,axp813-adc", */
+	}, {
+		.name		= "axp20x-battery-power-supply",
+		/* .of_compatible	= "x-powers,axp813-battery-power-supply", */
+	}, {
+		.name		= "axp20x-ac-power-supply",
+		/* .of_compatible	= "x-powers,axp813-ac-power-supply", */
+	}, {
+		.name		= "axp20x-usb-power-supply",
+		/* .of_compatible	= "x-powers,axp813-usb-power-supply", */
+	},
+	{	.name		= "axp20x-regulator" },
+};
+
+static const struct mfd_cell axp806_cells[] = {
+	{
+		.name		= "axp20x-regulator",
+	},
+};
+
+static const struct mfd_cell axp809_cells[] = {
+	{
+		.name		= "axp221-pek",
+	}, {
+		.name		= "axp20x-regulator",
+	},
+};
+
+static const struct mfd_cell axp813_cells[] = {
+	{
+		.name		= "axp221-pek",
+	}, {
+		.name		= "axp20x-regulator",
+	}, {
+		.name		= "axp20x-gpio",
+		/* .of_compatible	= "x-powers,axp813-gpio", */
+	}, {
+		.name		= "axp813-adc",
+		/* .of_compatible	= "x-powers,axp813-adc", */
+	}, {
+		.name		= "axp20x-battery-power-supply",
+		/* .of_compatible	= "x-powers,axp813-battery-power-supply", */
+	}, {
+		.name		= "axp20x-ac-power-supply",
+		/* .of_compatible	= "x-powers,axp813-ac-power-supply", */
+	}, {
+		.name		= "axp20x-usb-power-supply",
+		/* .of_compatible	= "x-powers,axp813-usb-power-supply", */
+	},
+};
+
+static void axp20x_power_off(struct poweroff_handler *handler)
+{
+	struct axp20x_dev *axp20x = container_of(handler, struct axp20x_dev, poweroff);
+
+	regmap_write(axp20x->regmap, AXP20X_OFF_CTRL, AXP20X_OFF);
+
+	shutdown_barebox();
+
+	/* Give capacitors etc. time to drain to avoid kernel panic msg. */
+	mdelay(500);
+	hang();
+}
+
+int axp20x_match_device(struct axp20x_dev *axp20x)
+{
+	struct device_d *dev = axp20x->dev;
+	const struct of_device_id *of_id;
+
+	of_id = of_match_device(dev->driver->of_compatible, dev);
+	if (!of_id) {
+		dev_err(dev, "Unable to match OF ID\n");
+		return -ENODEV;
+	}
+	axp20x->variant = (long)of_id->data;
+
+	switch (axp20x->variant) {
+	case AXP152_ID:
+		axp20x->nr_cells = ARRAY_SIZE(axp152_cells);
+		axp20x->cells = axp152_cells;
+		axp20x->regmap_cfg = &axp152_regmap_config;
+		break;
+	case AXP202_ID:
+	case AXP209_ID:
+		axp20x->nr_cells = ARRAY_SIZE(axp20x_cells);
+		axp20x->cells = axp20x_cells;
+		axp20x->regmap_cfg = &axp20x_regmap_config;
+		break;
+	case AXP221_ID:
+		axp20x->nr_cells = ARRAY_SIZE(axp221_cells);
+		axp20x->cells = axp221_cells;
+		axp20x->regmap_cfg = &axp22x_regmap_config;
+		break;
+	case AXP223_ID:
+		axp20x->nr_cells = ARRAY_SIZE(axp223_cells);
+		axp20x->cells = axp223_cells;
+		axp20x->regmap_cfg = &axp22x_regmap_config;
+		break;
+	case AXP288_ID:
+		axp20x->cells = axp288_cells;
+		axp20x->nr_cells = ARRAY_SIZE(axp288_cells);
+		axp20x->regmap_cfg = &axp288_regmap_config;
+		break;
+	case AXP803_ID:
+		axp20x->nr_cells = ARRAY_SIZE(axp803_cells);
+		axp20x->cells = axp803_cells;
+		axp20x->regmap_cfg = &axp288_regmap_config;
+		break;
+	case AXP806_ID:
+		/*
+		 * Don't register the power key part if in slave mode or
+		 * if there is no interrupt line.
+		 */
+		axp20x->nr_cells = ARRAY_SIZE(axp806_cells);
+		axp20x->cells = axp806_cells;
+		axp20x->regmap_cfg = &axp806_regmap_config;
+		break;
+	case AXP809_ID:
+		axp20x->nr_cells = ARRAY_SIZE(axp809_cells);
+		axp20x->cells = axp809_cells;
+		axp20x->regmap_cfg = &axp22x_regmap_config;
+		break;
+	case AXP813_ID:
+		axp20x->nr_cells = ARRAY_SIZE(axp813_cells);
+		axp20x->cells = axp813_cells;
+		axp20x->regmap_cfg = &axp288_regmap_config;
+		break;
+	default:
+		dev_err(dev, "unsupported AXP20X ID %lu\n", axp20x->variant);
+		return -EINVAL;
+	}
+	dev_info(dev, "AXP20x variant %s found\n",
+		 axp20x_model_names[axp20x->variant]);
+
+	return 0;
+}
+EXPORT_SYMBOL(axp20x_match_device);
+
+int axp20x_device_probe(struct axp20x_dev *axp20x)
+{
+	int ret;
+
+	/*
+	 * The AXP806 supports either master/standalone or slave mode.
+	 * Slave mode allows sharing the serial bus, even with multiple
+	 * AXP806 which all have the same hardware address.
+	 *
+	 * This is done with extra "serial interface address extension",
+	 * or AXP806_BUS_ADDR_EXT, and "register address extension", or
+	 * AXP806_REG_ADDR_EXT, registers. The former is read-only, with
+	 * 1 bit customizable at the factory, and 1 bit depending on the
+	 * state of an external pin. The latter is writable. The device
+	 * will only respond to operations to its other registers when
+	 * the these device addressing bits (in the upper 4 bits of the
+	 * registers) match.
+	 *
+	 * By default we support an AXP806 chained to an AXP809 in slave
+	 * mode. Boards which use an AXP806 in master mode can set the
+	 * property "x-powers,master-mode" to override the default.
+	 */
+	if (axp20x->variant == AXP806_ID) {
+		if (of_property_read_bool(axp20x->dev->device_node,
+					  "x-powers,master-mode") ||
+		    of_property_read_bool(axp20x->dev->device_node,
+					  "x-powers,self-working-mode"))
+			regmap_write(axp20x->regmap, AXP806_REG_ADDR_EXT,
+				     AXP806_REG_ADDR_EXT_ADDR_MASTER_MODE);
+		else
+			regmap_write(axp20x->regmap, AXP806_REG_ADDR_EXT,
+				     AXP806_REG_ADDR_EXT_ADDR_SLAVE_MODE);
+	}
+
+	ret = mfd_add_devices(axp20x->dev, axp20x->cells, axp20x->nr_cells);
+	if (ret)
+		return dev_err_probe(axp20x->dev, ret, "failed to add MFD devices\n");
+
+
+	axp20x->poweroff.name = "axp20x-poweroff";
+	axp20x->poweroff.poweroff = axp20x_power_off;
+	axp20x->poweroff.priority = 200;
+
+	if (axp20x->variant != AXP288_ID)
+		poweroff_handler_register(&axp20x->poweroff);
+
+	dev_info(axp20x->dev, "AXP20X driver loaded\n");
+
+	return 0;
+}
+EXPORT_SYMBOL(axp20x_device_probe);
+
+MODULE_DESCRIPTION("PMIC MFD core driver for AXP20X");
+MODULE_AUTHOR("Carlo Caione <carlo@caione.org>");
+MODULE_LICENSE("GPL");