[PATCH 3/3] power: supply: Add support MAX1721x battery monitor

["Alex A. Mihaylov" <minimumlaw@rambler.ru>]

Add support for battery monitor MAX1721x (power_supply class).
Maxim Semiconductor MAX1721x Standalone Fuel Gauge battery monitor.
MAX17211 used for singlecell, MAX17215 for multicell batteryes.
---
 drivers/power/supply/Kconfig            |  14 ++
 drivers/power/supply/Makefile           |   1 +
 drivers/power/supply/max1721x_battery.c | 357 ++++++++++++++++++++++++++++++++
 3 files changed, 372 insertions(+)
 create mode 100644 drivers/power/supply/max1721x_battery.c

diff --git a/drivers/power/supply/Kconfig b/drivers/power/supply/Kconfig
index da54ac88f0..d431d6f8aa 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
+	  1-Wire (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 3789a2c06f..c785d05e02 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 0000000000..aa0effec3d
--- /dev/null
+++ b/drivers/power/supply/max1721x_battery.c
@@ -0,0 +1,357 @@
+/*
+ * 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 "../../w1/slaves/w1_max1721x.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 device *dev;
+	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 max1721x_battery_probe(struct platform_device *pdev)
+{
+	struct power_supply_config psy_cfg = {};
+	struct max17211_device_info *info;
+
+	info = devm_kzalloc(&pdev->dev, sizeof(*info), GFP_KERNEL);
+	if (!info)
+		return -ENOMEM;
+
+	platform_set_drvdata(pdev, info);
+
+	info->dev = &pdev->dev;
+	info->w1_dev = pdev->dev.parent;
+	info->bat_desc.name = dev_name(&pdev->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;
+	/*
+	 * FixMe:
+	 * Device without no_thermal = true not register (err -22)
+	 * Len of platform device name "max17211-battery.X.auto"
+	 * more than 20 chars limit in THERMAL_NAME_LENGTH from
+	 * include/uapi/linux/thermal.h
+	 */
+	info->bat_desc.no_thermal = true;
+	psy_cfg.drv_data = info;
+
+	/* regmap init */
+	info->regmap = devm_regmap_init_w1(info->w1_dev,
+					&max1721x_regmap_w1_config);
+	if (IS_ERR(info->regmap)) {
+		int err = PTR_ERR(info->regmap);
+
+		dev_err(info->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->dev, "RSenese not calibrated, set 10 mOhms!\n");
+		info->rsense = 1000; /* in regs in 10^-5 */
+	}
+	dev_info(info->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->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->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->dev, "Can't read serial. Hardware error.\n");
+		return -ENODEV;
+	}
+
+	info->bat = devm_power_supply_register(&pdev->dev, &info->bat_desc,
+						&psy_cfg);
+	if (IS_ERR(info->bat)) {
+		dev_err(info->dev, "failed to register battery\n");
+		return PTR_ERR(info->bat);
+	}
+
+	return 0;
+}
+
+static struct platform_driver max1721x_battery_driver = {
+	.driver = {
+		.name = "max1721x-battery",
+	},
+	.probe	  = max1721x_battery_probe,
+};
+module_platform_driver(max1721x_battery_driver);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alex A. Mihaylov <minimumlaw@rambler.ru>");
+MODULE_DESCRIPTION("Maxim MAX17211/MAX17215 Fuel Gauage IC driver");
+MODULE_ALIAS("platform:max1721x-battery");
-- 
2.13.0