[RFC 0/2] Again w1-regman and power_supply MAX1721x

[RFC 0/2] Again w1-regman and power_supply MAX1721x

[Alex A. Mihaylov]

Hi!
I wrote driver for Maxim MAX17211/MAX17215 standalone fuel gauge IC. 

Earlier I post preliminary versions of this driver and got recommendations to
translate it into the infrastructure of regmap. Accordingly, it was necessary
to implement at least basic support of regmap for the OneWire bus. Which was 
done. There was a criticism about the use of an intermediate platform_device.
In this edition, this is also fixed.

I would like to hear not only criticism, but also constructive proposals
for the implementation or correction of this code.

Known issuie/troubles:
~~~~~~~~~~~~~~~~~~~~~~
1. Endian for W1-regmap
Code writen for use nativ endian for host (master) device. But waiting for
little-endian slave divice. I don't know W1 slave device with big-endian
addrees or data format. May be regmap_bus or regmap_config will be checked
for host/device endian requirements?

2. W1 Family/device infrastructure
All present power_supply class drivers in vanilla kernel use w1-slave devices.
All of them create platform_device with name "chip-battery.X.auto", and 
power_supply class driver use this platform device. Why used this way? I
write code, allocated power_supply at W1 slave (family) device register.
This work as expected.

3. Device names
All W1 device have unical 64 bit ID (8-bit family, 48-bit serial number,
8 bit CRC). W1 infrastructure show 56 bits (family-serial_nimber) as w1
slave device name. I use this (unical) device name as power_supply battery
name. This work. But in /sys/class/power_supply is placed machine readabe 
subdir "26-HexDigString", instead of human-readable "chip-battery.X.auto".
But in /sys/class/power_supply/26-HexDigString/type file still content
human-readable type "Battery".
Thermal zone working, but in /sys/class/thermal/thermal_zoneX/type also
placed "26-HexDigString", instead of "chip-battery.X.auto".
I can rename "26-HexDigString" to "battery-26-HexDigString" or 
"26-HexDigString-battery", but this exceeded 20 chars thermal zone device
name. So, thermal zone will have to be disabled.

Alex A. Mihaylov (2):
  Basic support for regmap ifrastucture over Maxim/Dalas OneWire Bus
  MAX1721x Standalone Fuel Gauge IC power_supply class driver

 drivers/base/regmap/Kconfig             |   6 +-
 drivers/base/regmap/Makefile            |   1 +
 drivers/base/regmap/regmap-w1.c         | 241 +++++++++++++++++++++
 drivers/power/supply/Kconfig            |  14 ++
 drivers/power/supply/Makefile           |   1 +
 drivers/power/supply/max1721x_battery.c | 361 ++++++++++++++++++++++++++++++++
 include/linux/power/max172xx-battery.h  | 100 +++++++++
 include/linux/regmap.h                  |  34 +++
 8 files changed, 757 insertions(+), 1 deletion(-)
 create mode 100644 drivers/base/regmap/regmap-w1.c
 create mode 100644 drivers/power/supply/max1721x_battery.c
 create mode 100644 include/linux/power/max172xx-battery.h

-- 
2.8.4 (Apple Git-73)

[RFC 1/2] Basic support for regmap ifrastucture over Maxim/Dalas OneWire Bus

[Alex A. Mihaylov]

---
 drivers/base/regmap/Kconfig     |   6 +-
 drivers/base/regmap/Makefile    |   1 +
 drivers/base/regmap/regmap-w1.c | 241 ++++++++++++++++++++++++++++++++++++++++
 include/linux/regmap.h          |  34 ++++++
 4 files changed, 281 insertions(+), 1 deletion(-)
 create mode 100644 drivers/base/regmap/regmap-w1.c

diff --git a/drivers/base/regmap/Kconfig b/drivers/base/regmap/Kconfig
index db9d00c..413af5f 100644
--- a/drivers/base/regmap/Kconfig
+++ b/drivers/base/regmap/Kconfig
@@ -3,7 +3,7 @@
 # subsystems should select the appropriate symbols.
 
 config REGMAP
-	default y if (REGMAP_I2C || REGMAP_SPI || REGMAP_SPMI || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ)
+	default y if (REGMAP_I2C || REGMAP_SPI || REGMAP_SPMI || REGMAP_W1 || REGMAP_AC97 || REGMAP_MMIO || REGMAP_IRQ)
 	select LZO_COMPRESS
 	select LZO_DECOMPRESS
 	select IRQ_DOMAIN if REGMAP_IRQ
@@ -24,6 +24,10 @@ config REGMAP_SPMI
 	tristate
 	depends on SPMI
 
+config REGMAP_W1
+	tristate
+	depends on W1
+
 config REGMAP_MMIO
 	tristate
 
diff --git a/drivers/base/regmap/Makefile b/drivers/base/regmap/Makefile
index 609e4c8..17741ae 100644
--- a/drivers/base/regmap/Makefile
+++ b/drivers/base/regmap/Makefile
@@ -10,3 +10,4 @@ obj-$(CONFIG_REGMAP_SPI) += regmap-spi.o
 obj-$(CONFIG_REGMAP_SPMI) += regmap-spmi.o
 obj-$(CONFIG_REGMAP_MMIO) += regmap-mmio.o
 obj-$(CONFIG_REGMAP_IRQ) += regmap-irq.o
+obj-$(CONFIG_REGMAP_W1) += regmap-w1.o
diff --git a/drivers/base/regmap/regmap-w1.c b/drivers/base/regmap/regmap-w1.c
new file mode 100644
index 0000000..6d042cb
--- /dev/null
+++ b/drivers/base/regmap/regmap-w1.c
@@ -0,0 +1,241 @@
+/*
+ * Register map access API - W1 (OneWire) support
+ *
+ * Copyright (C) 2017 OAO Radioavionica
+ * Author: Alex A. Mihaylov <minimumlaw@rambler.ru>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation
+ */
+
+#include <linux/regmap.h>
+#include <linux/module.h>
+#include "../../w1/w1.h"
+
+#include "internal.h"
+
+#define W1_CMD_READ_DATA	0x69
+#define W1_CMD_WRITE_DATA	0x6C
+
+/*
+ * OneWire slaves registers with addess 8 bit and data 8 bit
+ */
+
+static int w1_reg_a8_v8_read(void *context, unsigned int reg, unsigned int *val)
+{
+	struct device *dev = context;
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+	int ret = -ENODEV;
+
+
+	if (reg > 255)
+		return -EINVAL;
+
+	mutex_lock(&sl->master->bus_mutex);
+	if (!w1_reset_select_slave(sl)) {
+		w1_write_8(sl->master, W1_CMD_READ_DATA);
+		w1_write_8(sl->master, reg);
+		*val = w1_read_8(sl->master);
+		ret = 0;
+	}
+	mutex_unlock(&sl->master->bus_mutex);
+
+	return ret;
+}
+
+static int w1_reg_a8_v8_write(void *context, unsigned int reg, unsigned int val)
+{
+	struct device *dev = context;
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+	int ret = -ENODEV;
+
+
+	if (reg > 255)
+		return -EINVAL;
+
+	mutex_lock(&sl->master->bus_mutex);
+	if (!w1_reset_select_slave(sl)) {
+		w1_write_8(sl->master, W1_CMD_WRITE_DATA);
+		w1_write_8(sl->master, reg);
+		w1_write_8(sl->master, val);
+		ret = 0;
+	}
+	mutex_unlock(&sl->master->bus_mutex);
+
+	return ret;
+}
+
+static struct regmap_bus regmap_w1_bus_a8_v8 = {
+	.reg_read = w1_reg_a8_v8_read,
+	.reg_write = w1_reg_a8_v8_write,
+};
+
+/*
+ * OneWire slaves registers with addess 8 bit and data 16 bit
+ */
+
+static int w1_reg_a8_v16_read(void *context, unsigned int reg,
+				unsigned int *val)
+{
+	struct device *dev = context;
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+	int ret = -ENODEV;
+
+
+	if (reg > 255)
+		return -EINVAL;
+
+	mutex_lock(&sl->master->bus_mutex);
+	if (!w1_reset_select_slave(sl)) {
+		w1_write_8(sl->master, W1_CMD_READ_DATA);
+		w1_write_8(sl->master, reg);
+		*val = w1_read_8(sl->master);
+		*val |= w1_read_8(sl->master)<<8;
+		ret = 0;
+	}
+	mutex_unlock(&sl->master->bus_mutex);
+
+	return ret;
+}
+
+static int w1_reg_a8_v16_write(void *context, unsigned int reg,
+				unsigned int val)
+{
+	struct device *dev = context;
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+	int ret = -ENODEV;
+
+
+	if (reg > 255)
+		return -EINVAL;
+
+	mutex_lock(&sl->master->bus_mutex);
+	if (!w1_reset_select_slave(sl)) {
+		w1_write_8(sl->master, W1_CMD_WRITE_DATA);
+		w1_write_8(sl->master, reg);
+		w1_write_8(sl->master, val & 0x00FF);
+		w1_write_8(sl->master, val>>8 & 0x00FF);
+		ret = 0;
+	}
+	mutex_unlock(&sl->master->bus_mutex);
+
+	return ret;
+}
+
+static struct regmap_bus regmap_w1_bus_a8_v16 = {
+	.reg_read = w1_reg_a8_v16_read,
+	.reg_write = w1_reg_a8_v16_write,
+};
+
+/*
+ * OneWire slaves registers with addess 16 bit and data 16 bit
+ */
+
+static int w1_reg_a16_v16_read(void *context, unsigned int reg,
+				unsigned int *val)
+{
+	struct device *dev = context;
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+	int ret = -ENODEV;
+
+
+	if (reg > 65535)
+		return -EINVAL;
+
+	mutex_lock(&sl->master->bus_mutex);
+	if (!w1_reset_select_slave(sl)) {
+		w1_write_8(sl->master, W1_CMD_READ_DATA);
+		w1_write_8(sl->master, reg & 0x00FF);
+		w1_write_8(sl->master, reg>>8 & 0x00FF);
+		*val = w1_read_8(sl->master);
+		*val |= w1_read_8(sl->master)<<8;
+		ret = 0;
+	}
+	mutex_unlock(&sl->master->bus_mutex);
+
+	return ret;
+}
+
+static int w1_reg_a16_v16_write(void *context, unsigned int reg,
+				unsigned int val)
+{
+	struct device *dev = context;
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+	int ret = -ENODEV;
+
+
+	if (reg > 65535)
+		return -EINVAL;
+
+	mutex_lock(&sl->master->bus_mutex);
+	if (!w1_reset_select_slave(sl)) {
+		w1_write_8(sl->master, W1_CMD_WRITE_DATA);
+		w1_write_8(sl->master, reg & 0x00FF);
+		w1_write_8(sl->master, reg>>8 & 0x00FF);
+		w1_write_8(sl->master, val & 0x00FF);
+		w1_write_8(sl->master, val>>8 & 0x00FF);
+		ret = 0;
+	}
+	mutex_unlock(&sl->master->bus_mutex);
+
+	return ret;
+}
+
+static struct regmap_bus regmap_w1_bus_a16_v16 = {
+	.reg_read = w1_reg_a16_v16_read,
+	.reg_write = w1_reg_a16_v16_write,
+};
+
+static const struct regmap_bus *regmap_get_w1_bus(struct device *w1_dev,
+					const struct regmap_config *config)
+{
+	if (config->reg_bits == 8 && config->val_bits == 8)
+		return &regmap_w1_bus_a8_v8;
+
+	if (config->reg_bits == 8 && config->val_bits == 16)
+		return &regmap_w1_bus_a8_v16;
+
+	if (config->reg_bits == 16 && config->val_bits == 16)
+		return &regmap_w1_bus_a16_v16;
+
+	return ERR_PTR(-ENOTSUPP);
+}
+
+struct regmap *__regmap_init_w1(struct device *w1_dev,
+				 const struct regmap_config *config,
+				 struct lock_class_key *lock_key,
+				 const char *lock_name)
+{
+
+	const struct regmap_bus *bus = regmap_get_w1_bus(w1_dev, config);
+
+	if (IS_ERR(bus))
+		return ERR_CAST(bus);
+
+	return __regmap_init(w1_dev, bus, w1_dev, config,
+			 lock_key, lock_name);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(__regmap_init_w1);
+
+struct regmap *__devm_regmap_init_w1(struct device *w1_dev,
+				 const struct regmap_config *config,
+				 struct lock_class_key *lock_key,
+				 const char *lock_name)
+{
+
+	const struct regmap_bus *bus = regmap_get_w1_bus(w1_dev, config);
+
+	if (IS_ERR(bus))
+		return ERR_CAST(bus);
+
+	return __devm_regmap_init(w1_dev, bus, w1_dev, config,
+				 lock_key, lock_name);
+
+	return NULL;
+}
+EXPORT_SYMBOL_GPL(__devm_regmap_init_w1);
+
+MODULE_LICENSE("GPL");
diff --git a/include/linux/regmap.h b/include/linux/regmap.h
index e886492..86eeacc 100644
--- a/include/linux/regmap.h
+++ b/include/linux/regmap.h
@@ -461,6 +461,10 @@ struct regmap *__regmap_init_spmi_ext(struct spmi_device *dev,
 				      const struct regmap_config *config,
 				      struct lock_class_key *lock_key,
 				      const char *lock_name);
+struct regmap *__regmap_init_w1(struct device *w1_dev,
+				 const struct regmap_config *config,
+				 struct lock_class_key *lock_key,
+				 const char *lock_name);
 struct regmap *__regmap_init_mmio_clk(struct device *dev, const char *clk_id,
 				      void __iomem *regs,
 				      const struct regmap_config *config,
@@ -493,6 +497,10 @@ struct regmap *__devm_regmap_init_spmi_ext(struct spmi_device *dev,
 					   const struct regmap_config *config,
 					   struct lock_class_key *lock_key,
 					   const char *lock_name);
+struct regmap *__devm_regmap_init_w1(struct device *w1_dev,
+				      const struct regmap_config *config,
+				      struct lock_class_key *lock_key,
+				      const char *lock_name);
 struct regmap *__devm_regmap_init_mmio_clk(struct device *dev,
 					   const char *clk_id,
 					   void __iomem *regs,
@@ -597,6 +605,19 @@ int regmap_attach_dev(struct device *dev, struct regmap *map,
 				dev, config)
 
 /**
+ * regmap_init_w1() - Initialise register map
+ *
+ * @w1_dev: Device that will be interacted with
+ * @config: Configuration for register map
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer to
+ * a struct regmap.
+ */
+#define regmap_init_w1(w1_dev, config)					\
+	__regmap_lockdep_wrapper(__regmap_init_w1, #config,		\
+				w1_dev, config)
+
+/**
  * regmap_init_mmio_clk() - Initialise register map with register clock
  *
  * @dev: Device that will be interacted with
@@ -712,6 +733,19 @@ bool regmap_ac97_default_volatile(struct device *dev, unsigned int reg);
 				dev, config)
 
 /**
+ * devm_regmap_init_w1() - Initialise managed register map
+ *
+ * @w1_dev: Device that will be interacted with
+ * @config: Configuration for register map
+ *
+ * The return value will be an ERR_PTR() on error or a valid pointer
+ * to a struct regmap.  The regmap will be automatically freed by the
+ * device management code.
+ */
+#define devm_regmap_init_w1(w1_dev, config)				\
+	__regmap_lockdep_wrapper(__devm_regmap_init_w1, #config,	\
+				w1_dev, config)
+/**
  * devm_regmap_init_mmio_clk() - Initialise managed register map with clock
  *
  * @dev: Device that will be interacted with
-- 
2.8.4 (Apple Git-73)

[RFC 2/2] MAX1721x Standalone Fuel Gauge IC power_supply class driver

[Alex A. Mihaylov]

---
 drivers/power/supply/Kconfig            |  14 ++
 drivers/power/supply/Makefile           |   1 +
 drivers/power/supply/max1721x_battery.c | 361 ++++++++++++++++++++++++++++++++
 include/linux/power/max172xx-battery.h  | 100 +++++++++
 4 files changed, 476 insertions(+)
 create mode 100644 drivers/power/supply/max1721x_battery.c
 create mode 100644 include/linux/power/max172xx-battery.h

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index da54ac8..0df90ac 100644
--- a/drivers/power/supply/Kconfig
+++ b/drivers/power/supply/Kconfig
@@ -268,6 +268,20 @@ config BATTERY_MAX17042
 	  with MAX17042. This driver also supports max17047/50 chips which are
 	  improved version of max17042.
 
+config BATTERY_MAX1721X
+	tristate "MAX17211/MAX17215 standalone gas-gauge"
+	depends on W1
+	select W1_SLAVE_MAX1721X
+	select REGMAP_W1
+	help
+	  MAX1721x is fuel-gauge systems for lithium-ion (Li+) batteries
+	  in handheld and portable equipment. MAX17211 used with single cell
+	  battery. MAX17215 designed for muticell battery. Both them have
+	  OneWire (W1) host interface.
+
+	  Say Y here to enable support for the MAX17211/MAX17215 standalone
+	  battery gas-gauge.
+
 config BATTERY_Z2
 	tristate "Z2 battery driver"
 	depends on I2C && MACH_ZIPIT2
diff --git a/drivers/power/supply/Makefile b/drivers/power/supply/Makefile
index 3789a2c..c785d05 100644
--- a/drivers/power/supply/Makefile
+++ b/drivers/power/supply/Makefile
@@ -41,6 +41,7 @@ obj-$(CONFIG_CHARGER_DA9150)	+= da9150-charger.o
 obj-$(CONFIG_BATTERY_DA9150)	+= da9150-fg.o
 obj-$(CONFIG_BATTERY_MAX17040)	+= max17040_battery.o
 obj-$(CONFIG_BATTERY_MAX17042)	+= max17042_battery.o
+obj-$(CONFIG_BATTERY_MAX1721X)	+= max1721x_battery.o
 obj-$(CONFIG_BATTERY_Z2)	+= z2_battery.o
 obj-$(CONFIG_BATTERY_RT5033)	+= rt5033_battery.o
 obj-$(CONFIG_CHARGER_RT9455)	+= rt9455_charger.o
diff --git a/drivers/power/supply/max1721x_battery.c b/drivers/power/supply/max1721x_battery.c
new file mode 100644
index 0000000..5b0bbb0
--- /dev/null
+++ b/drivers/power/supply/max1721x_battery.c
@@ -0,0 +1,361 @@
+/*
+ * 1-wire client/driver for the Maxim Semicondactor
+ * MAX17211/MAX17215 Standalone Fuel Gauge IC
+ *
+ * Copyright (C) 2017 OAO Radioavionica
+ * Author: Alex A. Mihaylov <minimumlaw@rambler.ru>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ */
+
+#include <linux/module.h>
+#include <linux/slab.h>
+#include <linux/param.h>
+#include <linux/pm.h>
+#include <linux/regmap.h>
+#include <linux/platform_device.h>
+#include <linux/power_supply.h>
+#include <linux/idr.h>
+
+#include "../../w1/w1.h"
+#include "linux/power/max172xx-battery.h"
+
+#define DEF_DEV_NAME_MAX17211	"MAX17211"
+#define DEF_DEV_NAME_MAX17215	"MAX17215"
+#define DEF_DEV_NAME_UNKNOWN	"UNKNOWN"
+#define DEF_MFG_NAME		"MAXIM"
+
+struct max17211_device_info {
+	struct power_supply *bat;
+	struct power_supply_desc bat_desc;
+	struct device *w1_dev;
+	struct regmap *regmap;
+	/* battery design format */
+	unsigned int rsense; /* in tenths uOhm */
+	char DeviceName[2 * MAX1721X_REG_DEV_NUMB + 1];
+	char ManufacturerName[2 * MAX1721X_REG_MFG_NUMB + 1];
+	char SerialNumber[13]; /* see get_sn_str() later for comment */
+};
+
+static inline struct max17211_device_info *
+to_device_info(struct power_supply *psy)
+{
+	return power_supply_get_drvdata(psy);
+}
+
+static int max1721x_battery_get_property(struct power_supply *psy,
+	enum power_supply_property psp,
+	union power_supply_propval *val)
+{
+	struct max17211_device_info *info = to_device_info(psy);
+	unsigned int reg = 0;
+	int ret = 0;
+
+	switch (psp) {
+	case POWER_SUPPLY_PROP_PRESENT:
+		/*
+		 * POWER_SUPPLY_PROP_PRESENT will always readable via
+		 * sysfs interface. Value return 0 if battery not
+		 * present or unaccesable via W1.
+		 */
+		val->intval =
+			regmap_read(info->regmap, MAX172XX_REG_STATUS,
+			&reg) ? 0 : !(reg & MAX172XX_BAT_PRESENT);
+		break;
+	case POWER_SUPPLY_PROP_CAPACITY:
+		ret = regmap_read(info->regmap, MAX172XX_REG_REPSOC, &reg);
+		val->intval = max172xx_percent_to_ps(reg);
+		break;
+	case POWER_SUPPLY_PROP_VOLTAGE_NOW:
+		ret = regmap_read(info->regmap, MAX172XX_REG_BATT, &reg);
+		val->intval = max172xx_voltage_to_ps(reg);
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN:
+		ret = regmap_read(info->regmap, MAX172XX_REG_DESIGNCAP, &reg);
+		val->intval = max172xx_capacity_to_ps(reg);
+		break;
+	case POWER_SUPPLY_PROP_CHARGE_AVG:
+		ret = regmap_read(info->regmap, MAX172XX_REG_REPCAP, &reg);
+		val->intval = max172xx_capacity_to_ps(reg);
+		break;
+	case POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG:
+		ret = regmap_read(info->regmap, MAX172XX_REG_TTE, &reg);
+		val->intval = max172xx_time_to_ps(reg);
+		break;
+	case POWER_SUPPLY_PROP_TIME_TO_FULL_AVG:
+		ret = regmap_read(info->regmap, MAX172XX_REG_TTF, &reg);
+		val->intval = max172xx_time_to_ps(reg);
+		break;
+	case POWER_SUPPLY_PROP_TEMP:
+		ret = regmap_read(info->regmap, MAX172XX_REG_TEMP, &reg);
+		val->intval = max172xx_temperature_to_ps(reg);
+		break;
+	/* We need signed current, so must cast info->rsense to signed type */
+	case POWER_SUPPLY_PROP_CURRENT_NOW:
+		ret = regmap_read(info->regmap, MAX172XX_REG_CURRENT, &reg);
+		val->intval =
+			max172xx_current_to_voltage(reg) / (int)info->rsense;
+		break;
+	case POWER_SUPPLY_PROP_CURRENT_AVG:
+		ret = regmap_read(info->regmap, MAX172XX_REG_AVGCURRENT, &reg);
+		val->intval =
+			max172xx_current_to_voltage(reg) / (int)info->rsense;
+		break;
+	/*
+	 * Strings already received and inited by probe.
+	 * We do dummy read for check battery still available.
+	 */
+	case POWER_SUPPLY_PROP_MODEL_NAME:
+		ret = regmap_read(info->regmap, MAX1721X_REG_DEV_STR, &reg);
+		val->strval = info->DeviceName;
+		break;
+	case POWER_SUPPLY_PROP_MANUFACTURER:
+		ret = regmap_read(info->regmap, MAX1721X_REG_MFG_STR, &reg);
+		val->strval = info->ManufacturerName;
+		break;
+	case POWER_SUPPLY_PROP_SERIAL_NUMBER:
+		ret = regmap_read(info->regmap, MAX1721X_REG_SER_HEX, &reg);
+		val->strval = info->SerialNumber;
+		break;
+	default:
+		ret = -EINVAL;
+	}
+
+	return ret;
+}
+
+static enum power_supply_property max1721x_battery_props[] = {
+	/* int */
+	POWER_SUPPLY_PROP_PRESENT,
+	POWER_SUPPLY_PROP_CAPACITY,
+	POWER_SUPPLY_PROP_VOLTAGE_NOW,
+	POWER_SUPPLY_PROP_CHARGE_FULL_DESIGN,
+	POWER_SUPPLY_PROP_CHARGE_AVG,
+	POWER_SUPPLY_PROP_TIME_TO_EMPTY_AVG,
+	POWER_SUPPLY_PROP_TIME_TO_FULL_AVG,
+	POWER_SUPPLY_PROP_TEMP,
+	POWER_SUPPLY_PROP_CURRENT_NOW,
+	POWER_SUPPLY_PROP_CURRENT_AVG,
+	/* strings */
+	POWER_SUPPLY_PROP_MODEL_NAME,
+	POWER_SUPPLY_PROP_MANUFACTURER,
+	POWER_SUPPLY_PROP_SERIAL_NUMBER,
+};
+
+static int get_string(struct max17211_device_info *info,
+			uint16_t reg, uint8_t nr, char *str)
+{
+	unsigned int val;
+
+	if (!str || !(reg == MAX1721X_REG_MFG_STR ||
+			reg == MAX1721X_REG_DEV_STR))
+		return -EFAULT;
+
+	while (nr--) {
+		if (regmap_read(info->regmap, reg++, &val))
+			return -EFAULT;
+		*str++ = val>>8 & 0x00FF;
+		*str++ = val & 0x00FF;
+	}
+	return 0;
+}
+
+/* Maxim say: Serial number is a hex string up to 12 hex characters */
+static int get_sn_string(struct max17211_device_info *info, char *str)
+{
+	unsigned int val[3];
+
+	if (!str)
+		return -EFAULT;
+
+	if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX, &val[0]))
+		return -EFAULT;
+	if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX + 1, &val[1]))
+		return -EFAULT;
+	if (regmap_read(info->regmap, MAX1721X_REG_SER_HEX + 2, &val[2]))
+		return -EFAULT;
+
+	snprintf(str, 13, "%04X%04X%04X", val[0], val[1], val[2]);
+	return 0;
+}
+
+/* Model Gauge M5 Register Memory Map access */
+static const struct regmap_range max1721x_regs_allow[] = {
+	/* M5 Model Gauge Algorithm area */
+	regmap_reg_range(0x00, 0x23),
+	regmap_reg_range(0x27, 0x2F),
+	regmap_reg_range(0x32, 0x32),
+	regmap_reg_range(0x35, 0x36),
+	regmap_reg_range(0x38, 0x3A),
+	regmap_reg_range(0x3D, 0x3F),
+	regmap_reg_range(0x42, 0x42),
+	regmap_reg_range(0x45, 0x46),
+	regmap_reg_range(0x4A, 0x4A),
+	regmap_reg_range(0x4D, 0x4D),
+	regmap_reg_range(0xB0, 0xB0),
+	regmap_reg_range(0xB4, 0xB4),
+	regmap_reg_range(0xB8, 0xBE),
+	regmap_reg_range(0xD1, 0xDA),
+	regmap_reg_range(0xDC, 0xDF),
+	/* Factory settins area */
+	regmap_reg_range(0x180, 0x1DF),
+	{ }
+};
+
+static const struct regmap_range max1721x_regs_deny[] = {
+	regmap_reg_range(0x24, 0x26),
+	regmap_reg_range(0x30, 0x31),
+	regmap_reg_range(0x33, 0x34),
+	regmap_reg_range(0x37, 0x37),
+	regmap_reg_range(0x3B, 0x3C),
+	regmap_reg_range(0x40, 0x41),
+	regmap_reg_range(0x43, 0x44),
+	regmap_reg_range(0x47, 0x49),
+	regmap_reg_range(0x4B, 0x4C),
+	regmap_reg_range(0x4E, 0xAF),
+	regmap_reg_range(0xB1, 0xB3),
+	regmap_reg_range(0xB5, 0xB7),
+	regmap_reg_range(0xBF, 0xD0),
+	regmap_reg_range(0xDB, 0xDB),
+	regmap_reg_range(0xE0, 0x17F),
+	{ }
+};
+
+static const struct regmap_access_table max1721x_regs = {
+	.yes_ranges	= max1721x_regs_allow,
+	.n_yes_ranges	= ARRAY_SIZE(max1721x_regs_allow),
+	.no_ranges	= max1721x_regs_deny,
+	.n_no_ranges	= ARRAY_SIZE(max1721x_regs_deny),
+};
+
+/* W1 regmap config */
+static const struct regmap_config max1721x_regmap_w1_config = {
+	.reg_bits = 16,
+	.val_bits = 16,
+	.volatile_table = &max1721x_regs,
+	.max_register = MAX1721X_MAX_REG_NR,
+};
+
+static int w1_max1721x_add_device(struct w1_slave *sl)
+{
+	struct power_supply_config psy_cfg = {};
+	struct max17211_device_info *info;
+
+	info = devm_kzalloc(&sl->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	sl->family_data = (void *)info;
+
+	info->w1_dev = &sl->dev;
+	info->bat_desc.name = dev_name(&sl->dev);
+	info->bat_desc.type = POWER_SUPPLY_TYPE_BATTERY;
+	info->bat_desc.properties = max1721x_battery_props;
+	info->bat_desc.num_properties = ARRAY_SIZE(max1721x_battery_props);
+	info->bat_desc.get_property = max1721x_battery_get_property;
+	psy_cfg.drv_data = info;
+
+	/* regmap init */
+	info->regmap = regmap_init_w1(info->w1_dev,
+					&max1721x_regmap_w1_config);
+	if (IS_ERR(info->regmap)) {
+		int err = PTR_ERR(info->regmap);
+
+		dev_err(info->w1_dev, "Failed to allocate register map: %d\n",
+			err);
+		return err;
+	}
+
+	/* rsense init */
+	info->rsense = 0;
+	if (regmap_read(info->regmap, MAX1721X_REG_NRSENSE, &info->rsense))
+
+	if (!info->rsense) {
+		dev_warn(info->w1_dev, "RSenese not calibrated, set 10 mOhms!\n");
+		info->rsense = 1000; /* in regs in 10^-5 */
+	}
+	dev_info(info->w1_dev, "RSense: %d mOhms.\n", info->rsense / 100);
+
+	if (get_string(info, MAX1721X_REG_MFG_STR,
+			MAX1721X_REG_MFG_NUMB, info->ManufacturerName)) {
+		dev_err(info->w1_dev, "Can't read manufacturer. Hardware error.\n");
+		return -ENODEV;
+	}
+
+	if (!info->ManufacturerName[0])
+		strncpy(info->ManufacturerName, DEF_MFG_NAME,
+			2 * MAX1721X_REG_MFG_NUMB);
+
+	if (get_string(info, MAX1721X_REG_DEV_STR,
+			MAX1721X_REG_DEV_NUMB, info->DeviceName)) {
+		dev_err(info->w1_dev, "Can't read device. Hardware error.\n");
+		return -ENODEV;
+	}
+	if (!info->DeviceName[0]) {
+		unsigned int dev_name;
+
+		if (regmap_read(info->regmap,
+				MAX172XX_REG_DEVNAME, &dev_name)) {
+			dev_err(info->w1_dev, "Can't read device name reg.\n");
+			return -ENODEV;
+		}
+
+		switch (dev_name & MAX172XX_DEV_MASK) {
+		case MAX172X1_DEV:
+			strncpy(info->DeviceName, DEF_DEV_NAME_MAX17211,
+				2 * MAX1721X_REG_DEV_NUMB);
+			break;
+		case MAX172X5_DEV:
+			strncpy(info->DeviceName, DEF_DEV_NAME_MAX17215,
+				2 * MAX1721X_REG_DEV_NUMB);
+			break;
+		default:
+			strncpy(info->DeviceName, DEF_DEV_NAME_UNKNOWN,
+				2 * MAX1721X_REG_DEV_NUMB);
+		}
+	}
+
+	if (get_sn_string(info, info->SerialNumber)) {
+		dev_err(info->w1_dev, "Can't read serial. Hardware error.\n");
+		return -ENODEV;
+	}
+
+	info->bat = power_supply_register(&sl->dev, &info->bat_desc,
+						&psy_cfg);
+	if (IS_ERR(info->bat)) {
+		dev_err(info->w1_dev, "failed to register battery\n");
+		return PTR_ERR(info->bat);
+	}
+
+	return 0;
+}
+
+static void w1_max1721x_remove_device(struct w1_slave *sl)
+{
+	struct max17211_device_info *info =
+		(struct max17211_device_info *)sl->family_data;
+
+	power_supply_unregister(info->bat);
+	regmap_exit(info->regmap);
+	kfree(info);
+}
+
+static struct w1_family_ops w1_max1721x_fops = {
+	.add_slave = w1_max1721x_add_device,
+	.remove_slave = w1_max1721x_remove_device,
+};
+
+static struct w1_family w1_max1721x_family = {
+	.fid = W1_MAX1721X_FAMILY_ID,
+	.fops = &w1_max1721x_fops,
+};
+
+module_w1_family(w1_max1721x_family);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alex A. Mihaylov <minimumlaw@rambler.ru>");
+MODULE_DESCRIPTION("Maxim MAX17211/MAX17215 Fuel Gauage IC driver");
+MODULE_ALIAS("w1-family-" __stringify(W1_MAX1721X_FAMILY_ID));
diff --git a/include/linux/power/max172xx-battery.h b/include/linux/power/max172xx-battery.h
new file mode 100644
index 0000000..c46ac56
--- /dev/null
+++ b/include/linux/power/max172xx-battery.h
@@ -0,0 +1,100 @@
+/*
+ * 1-Wire implementation for Maxim Semiconductor
+ * MAX7211/MAX17215 stanalone fuel gauge chip
+ *
+ * Copyright (C) 2017 OAO Radioavionica
+ * Author: Alex A. Mihaylov <minimumlaw@rambler.ru>
+ *
+ * Use consistent with the GNU GPL is permitted,
+ * provided that this copyright notice is
+ * preserved in its entirety in all copies and derived works.
+ *
+ */
+
+#ifndef __w1_max172xx_h__
+#define __w1_max172xx_h__
+
+/* Known commands to the MAX1721X chip */
+#define W1_MAX1721X_FAMILY_ID		0x26
+
+/* Factory settings (nonvilatile registers) (W1 specific) */
+
+#define MAX1721X_REG_NRSENSE	0x1CF	/* RSense in 10^-5 Ohm */
+/* Strings */
+#define MAX1721X_REG_MFG_STR	0x1CC
+#define MAX1721X_REG_MFG_NUMB	3
+#define MAX1721X_REG_DEV_STR	0x1DB
+#define MAX1721X_REG_DEV_NUMB	5
+/* HEX Strings */
+#define MAX1721X_REG_SER_HEX	0x1D8
+
+/* MAX172XX Output Registers for W1 chips */
+#define MAX172XX_REG_STATUS	0x000	/* status reg */
+#define MAX172XX_BAT_PRESENT	(1<<4)	/* battery connected bit */
+#define MAX172XX_REG_DEVNAME	0x021	/* chip config */
+#define MAX172XX_DEV_MASK	0x000F	/* chip type mask */
+#define MAX172X1_DEV		0x0001
+#define MAX172X5_DEV		0x0005
+#define MAX172XX_REG_TEMP	0x008	/* Temperature */
+#define MAX172XX_REG_BATT	0x0DA	/* Battery voltage */
+#define MAX172XX_REG_CURRENT	0x00A	/* Actual current */
+#define MAX172XX_REG_AVGCURRENT	0x00B	/* Average current */
+#define MAX172XX_REG_REPSOC	0x006	/* Percentage of charge */
+#define MAX172XX_REG_DESIGNCAP	0x018	/* Design capacity */
+#define MAX172XX_REG_REPCAP	0x005	/* Average capacity */
+#define MAX172XX_REG_TTE	0x011	/* Time to empty */
+#define MAX172XX_REG_TTF	0x020	/* Time to full */
+
+/* Number of valid register addresses in W1 mode */
+#define MAX1721X_MAX_REG_NR	0x1EF
+
+/* Convert regs value to power_supply units */
+
+static inline int max172xx_time_to_ps(unsigned int reg)
+{
+	return reg * 5625 / 1000;	/* in sec. */
+}
+
+static inline int max172xx_percent_to_ps(unsigned int reg)
+{
+	return reg / 256;	/* in percent from 0 to 100 */
+}
+
+static inline int max172xx_voltage_to_ps(unsigned int reg)
+{
+	return reg * 1250;	/* in uV */
+}
+
+static inline int max172xx_capacity_to_ps(unsigned int reg)
+{
+	return reg * 500;	/* in uAh */
+}
+
+/*
+ * Current and temperature is signed values, so unsigned regs
+ * value must be converted to signed type
+ */
+
+static inline int max172xx_temperature_to_ps(unsigned int reg)
+{
+	int val = (int16_t)(reg);
+
+	return val * 10 / 256; /* in tenths of deg. C */
+}
+
+/*
+ * Calculating current registers resolution:
+ *
+ * RSense stored in 10^-5 Ohm, so mesaurment voltage must be
+ * in 10^-11 Volts for get current in uA.
+ * 16 bit current reg fullscale +/-51.2mV is 102400 uV.
+ * So: 102400 / 65535 * 10^5 = 156252
+ */
+static inline int max172xx_current_to_voltage(unsigned int reg)
+{
+	int val = (int16_t)(reg);
+
+	return val * 156252;
+}
+
+#endif /* !__w1_max172xx_h__ */
-- 
2.8.4 (Apple Git-73)