[PATCH 0/3] w1-regmap infrastructure and MAX1721x power_suply

[PATCH 0/3] w1-regmap infrastructure and MAX1721x power_suply

[Alex A. Mihaylov]

  1. Introduce regmap infrastructure over Maxim/Dalas OneWire (W1) bus
  2. Introduce new OneWire (W1) family: 0x26 with slave device Maxim
     Semconductor MAX17211/MAX17215 Fuel Gauge IC
  3. Introduce Maxim Semiconductor MAX17211/MAX17215 Standalone Fuel Gauge
     IC support for power_supply class driver. This driver use w1-regmap API.

 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 | 357 ++++++++++++++++++++++++++++++++
 drivers/w1/slaves/Kconfig               |  12 ++
 drivers/w1/slaves/Makefile              |   1 +
 drivers/w1/slaves/w1_max1721x.c         |  73 +++++++
 drivers/w1/slaves/w1_max1721x.h         | 102 +++++++++
 drivers/w1/w1_family.h                  |   1 +
 include/linux/regmap.h                  |  34 +++
 12 files changed, 842 insertions(+), 1 deletion(-)
 create mode 100644 drivers/base/regmap/regmap-w1.c
 create mode 100644 drivers/power/supply/max1721x_battery.c
 create mode 100644 drivers/w1/slaves/w1_max1721x.c
 create mode 100644 drivers/w1/slaves/w1_max1721x.h

-- 
2.8.4 (Apple Git-73)

[PATCH 1/3] Introduce regmap infrastructure over Maxim/Dalas OneWire (W1) 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)

[PATCH 2/3] Introduce new OneWire (W1) family: 0x26 with slave device Maxim Semconductor MAX17211/MAX17215 Fuel Gauge IC

[Alex A. Mihaylov]

---
 drivers/w1/slaves/Kconfig       |  12 +++++
 drivers/w1/slaves/Makefile      |   1 +
 drivers/w1/slaves/w1_max1721x.c |  73 ++++++++++++++++++++++++++++
 drivers/w1/slaves/w1_max1721x.h | 102 ++++++++++++++++++++++++++++++++++++++++
 drivers/w1/w1_family.h          |   1 +
 5 files changed, 189 insertions(+)
 create mode 100644 drivers/w1/slaves/w1_max1721x.c
 create mode 100644 drivers/w1/slaves/w1_max1721x.h

diff --git a/drivers/w1/slaves/Kconfig b/drivers/w1/slaves/Kconfig
index 0ef9f26..06a63a1 100644
--- a/drivers/w1/slaves/Kconfig
+++ b/drivers/w1/slaves/Kconfig
@@ -86,6 +86,18 @@ config W1_SLAVE_DS2433_CRC
 	  Each block has 30 bytes of data and a two byte CRC16.
 	  Full block writes are only allowed if the CRC is valid.
 
+config W1_SLAVE_MAX1721X
+	tristate "Maxim MAX17211/MAX17215 battery monitor chip"
+	help
+	  If you enable this you will have the MAX17211/MAX17215 battery
+	  monitor chip support.
+
+	  The battery monitor chip is used in many batteries/devices
+	  as the one who is responsible for charging/discharging/monitoring
+	  Li+ batteries.
+
+	  If you are unsure, say N.
+
 config W1_SLAVE_DS2760
 	tristate "Dallas 2760 battery monitor chip (HP iPAQ & others)"
 	help
diff --git a/drivers/w1/slaves/Makefile b/drivers/w1/slaves/Makefile
index b4a3589..967329a 100644
--- a/drivers/w1/slaves/Makefile
+++ b/drivers/w1/slaves/Makefile
@@ -11,6 +11,7 @@ obj-$(CONFIG_W1_SLAVE_DS2406)	+= w1_ds2406.o
 obj-$(CONFIG_W1_SLAVE_DS2423)	+= w1_ds2423.o
 obj-$(CONFIG_W1_SLAVE_DS2431)	+= w1_ds2431.o
 obj-$(CONFIG_W1_SLAVE_DS2433)	+= w1_ds2433.o
+obj-$(CONFIG_W1_SLAVE_MAX1721X)	+= w1_max1721x.o
 obj-$(CONFIG_W1_SLAVE_DS2760)	+= w1_ds2760.o
 obj-$(CONFIG_W1_SLAVE_DS2780)	+= w1_ds2780.o
 obj-$(CONFIG_W1_SLAVE_DS2781)	+= w1_ds2781.o
diff --git a/drivers/w1/slaves/w1_max1721x.c b/drivers/w1/slaves/w1_max1721x.c
new file mode 100644
index 0000000..017ec3e
--- /dev/null
+++ b/drivers/w1/slaves/w1_max1721x.c
@@ -0,0 +1,73 @@
+/*
+ * 1-Wire implementation for Maxim Semiconductor
+ * MAX17211/MAX17215 standalone 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.
+ *
+ */
+
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/device.h>
+#include <linux/types.h>
+#include <linux/platform_device.h>
+#include <linux/mutex.h>
+#include <linux/idr.h>
+#include <linux/gfp.h>
+
+#include "../w1.h"
+#include "../w1_int.h"
+#include "../w1_family.h"
+#include "w1_max1721x.h"
+
+static int w1_max17211_add_device(struct w1_slave *sl)
+{
+	int ret;
+	struct platform_device *pdev;
+
+	pdev = platform_device_alloc("max1721x-battery", PLATFORM_DEVID_AUTO);
+	if (!pdev)
+		return -ENOMEM;
+	pdev->dev.parent = &sl->dev;
+
+	ret = platform_device_add(pdev);
+	if (ret)
+		goto pdev_add_failed;
+
+	dev_set_drvdata(&sl->dev, pdev);
+
+	return 0;
+
+pdev_add_failed:
+	platform_device_put(pdev);
+
+	return ret;
+}
+
+static void w1_max17211_remove_device(struct w1_slave *sl)
+{
+	struct platform_device *pdev = dev_get_drvdata(&sl->dev);
+
+	platform_device_unregister(pdev);
+}
+
+static struct w1_family_ops w1_max17211_fops = {
+	.add_slave    = w1_max17211_add_device,
+	.remove_slave = w1_max17211_remove_device,
+};
+
+static struct w1_family w1_max17211_family = {
+	.fid = W1_FAMILY_MAX17211,
+	.fops = &w1_max17211_fops,
+};
+module_w1_family(w1_max17211_family);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Alex A. Mihaylov <minimumlaw@rambler.ru>");
+MODULE_DESCRIPTION("1-wire Driver for MAX17211/MAX17215 battery monitor");
+MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_MAX17211));
diff --git a/drivers/w1/slaves/w1_max1721x.h b/drivers/w1/slaves/w1_max1721x.h
new file mode 100644
index 0000000..47694d9
--- /dev/null
+++ b/drivers/w1/slaves/w1_max1721x.h
@@ -0,0 +1,102 @@
+/*
+ * 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_max17211_h__
+#define __w1_max17211_h__
+
+/* Known commands to the MAX1721X chip */
+#define W1_MAX1721X_READ_DATA		0x69
+#define W1_MAX1721X_WRITE_DATA		0x6C
+
+/* 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
+
+/* MAX1721X/MAX17215 Output Registers for I2C and 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 */
+#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_max17211_h__ */
diff --git a/drivers/w1/w1_family.h b/drivers/w1/w1_family.h
index c4a6b25..398adc9 100644
--- a/drivers/w1/w1_family.h
+++ b/drivers/w1/w1_family.h
@@ -29,6 +29,7 @@
 #define W1_COUNTER_DS2423	0x1D
 #define W1_THERM_DS1822  	0x22
 #define W1_EEPROM_DS2433  	0x23
+#define W1_FAMILY_MAX17211	0x26
 #define W1_THERM_DS18B20 	0x28
 #define W1_FAMILY_DS2408	0x29
 #define W1_EEPROM_DS2431	0x2D
-- 
2.8.4 (Apple Git-73)

[PATCH 3/3] Introduce Maxim Semiconductor MAX17211/MAX17215 Standalone Fuel Gauge IC support for power_supply class driver.

[Alex A. Mihaylov]

This driver use regmap over W1 infrastructure
---
 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 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..aa0effe
--- /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");
-- 
2.8.4 (Apple Git-73)