w1: add Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC support

Add support for the Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC.

It was suggested to combine this functionality with the current ds2782
driver.  Unfortunately, I'm unable to commit the time to refactoring this
driver to that extent and I don't have a platform with the ds2782 part to
validate that there are no regression issues by adding this functionality.

[akpm@linux-foundation.org: use min_t()]
Signed-off-by: Clifton Barnes <cabarnes@indesign-llc.com>
Tested-by: Haojian Zhuang <haojian.zhuang@gmail.com>
Cc: Evgeniy Polyakov <johnpol@2ka.mipt.ru>
Cc: Ryan Mallon <ryan@bluewatersys.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 360 insertions, 0 deletions

diff --git a/drivers/w1/slaves/Kconfig b/drivers/w1/slaves/Kconfig
index cd1b72411bd4..d0cb01b42012 100644
--- a/drivers/w1/slaves/Kconfig
+++ b/drivers/w1/slaves/Kconfig
@@ -68,6 +68,19 @@ config W1_SLAVE_DS2760
 
 	  If you are unsure, say N.
 
+config W1_SLAVE_DS2780
+	tristate "Dallas 2780 battery monitor chip"
+	depends on W1
+	help
+	  If you enable this you will have the DS2780 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_BQ27000
 	tristate "BQ27000 slave support"
 	depends on W1
diff --git a/drivers/w1/slaves/Makefile b/drivers/w1/slaves/Makefile
index 75e3913910bb..1f31e9fb0b25 100644
--- a/drivers/w1/slaves/Makefile
+++ b/drivers/w1/slaves/Makefile
@@ -9,4 +9,5 @@ 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_DS2760)	+= w1_ds2760.o
+obj-$(CONFIG_W1_SLAVE_DS2780)	+= w1_ds2780.o
 obj-$(CONFIG_W1_SLAVE_BQ27000)	+= w1_bq27000.o
diff --git a/drivers/w1/slaves/w1_ds2780.c b/drivers/w1/slaves/w1_ds2780.c
new file mode 100644
index 000000000000..274c8f38303f
--- /dev/null
+++ b/drivers/w1/slaves/w1_ds2780.c
@@ -0,0 +1,217 @@
+/*
+ * 1-Wire implementation for the ds2780 chip
+ *
+ * Copyright (C) 2010 Indesign, LLC
+ *
+ * Author: Clifton Barnes <cabarnes@indesign-llc.com>
+ *
+ * Based on w1-ds2760 driver
+ *
+ * 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/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 "../w1.h"
+#include "../w1_int.h"
+#include "../w1_family.h"
+#include "w1_ds2780.h"
+
+int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
+			int io)
+{
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+
+	if (!dev)
+		return -ENODEV;
+
+	mutex_lock(&sl->master->mutex);
+
+	if (addr > DS2780_DATA_SIZE || addr < 0) {
+		count = 0;
+		goto out;
+	}
+	count = min_t(int, count, DS2780_DATA_SIZE - addr);
+
+	if (w1_reset_select_slave(sl) == 0) {
+		if (io) {
+			w1_write_8(sl->master, W1_DS2780_WRITE_DATA);
+			w1_write_8(sl->master, addr);
+			w1_write_block(sl->master, buf, count);
+			/* XXX w1_write_block returns void, not n_written */
+		} else {
+			w1_write_8(sl->master, W1_DS2780_READ_DATA);
+			w1_write_8(sl->master, addr);
+			count = w1_read_block(sl->master, buf, count);
+		}
+	}
+
+out:
+	mutex_unlock(&sl->master->mutex);
+
+	return count;
+}
+EXPORT_SYMBOL(w1_ds2780_io);
+
+int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)
+{
+	struct w1_slave *sl = container_of(dev, struct w1_slave, dev);
+
+	if (!dev)
+		return -EINVAL;
+
+	mutex_lock(&sl->master->mutex);
+
+	if (w1_reset_select_slave(sl) == 0) {
+		w1_write_8(sl->master, cmd);
+		w1_write_8(sl->master, addr);
+	}
+
+	mutex_unlock(&sl->master->mutex);
+	return 0;
+}
+EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);
+
+static ssize_t w1_ds2780_read_bin(struct file *filp,
+				  struct kobject *kobj,
+				  struct bin_attribute *bin_attr,
+				  char *buf, loff_t off, size_t count)
+{
+	struct device *dev = container_of(kobj, struct device, kobj);
+	return w1_ds2780_io(dev, buf, off, count, 0);
+}
+
+static struct bin_attribute w1_ds2780_bin_attr = {
+	.attr = {
+		.name = "w1_slave",
+		.mode = S_IRUGO,
+	},
+	.size = DS2780_DATA_SIZE,
+	.read = w1_ds2780_read_bin,
+};
+
+static DEFINE_IDR(bat_idr);
+static DEFINE_MUTEX(bat_idr_lock);
+
+static int new_bat_id(void)
+{
+	int ret;
+
+	while (1) {
+		int id;
+
+		ret = idr_pre_get(&bat_idr, GFP_KERNEL);
+		if (ret == 0)
+			return -ENOMEM;
+
+		mutex_lock(&bat_idr_lock);
+		ret = idr_get_new(&bat_idr, NULL, &id);
+		mutex_unlock(&bat_idr_lock);
+
+		if (ret == 0) {
+			ret = id & MAX_ID_MASK;
+			break;
+		} else if (ret == -EAGAIN) {
+			continue;
+		} else {
+			break;
+		}
+	}
+
+	return ret;
+}
+
+static void release_bat_id(int id)
+{
+	mutex_lock(&bat_idr_lock);
+	idr_remove(&bat_idr, id);
+	mutex_unlock(&bat_idr_lock);
+}
+
+static int w1_ds2780_add_slave(struct w1_slave *sl)
+{
+	int ret;
+	int id;
+	struct platform_device *pdev;
+
+	id = new_bat_id();
+	if (id < 0) {
+		ret = id;
+		goto noid;
+	}
+
+	pdev = platform_device_alloc("ds2780-battery", id);
+	if (!pdev) {
+		ret = -ENOMEM;
+		goto pdev_alloc_failed;
+	}
+	pdev->dev.parent = &sl->dev;
+
+	ret = platform_device_add(pdev);
+	if (ret)
+		goto pdev_add_failed;
+
+	ret = sysfs_create_bin_file(&sl->dev.kobj, &w1_ds2780_bin_attr);
+	if (ret)
+		goto bin_attr_failed;
+
+	dev_set_drvdata(&sl->dev, pdev);
+
+	return 0;
+
+bin_attr_failed:
+pdev_add_failed:
+	platform_device_unregister(pdev);
+pdev_alloc_failed:
+	release_bat_id(id);
+noid:
+	return ret;
+}
+
+static void w1_ds2780_remove_slave(struct w1_slave *sl)
+{
+	struct platform_device *pdev = dev_get_drvdata(&sl->dev);
+	int id = pdev->id;
+
+	platform_device_unregister(pdev);
+	release_bat_id(id);
+	sysfs_remove_bin_file(&sl->dev.kobj, &w1_ds2780_bin_attr);
+}
+
+static struct w1_family_ops w1_ds2780_fops = {
+	.add_slave    = w1_ds2780_add_slave,
+	.remove_slave = w1_ds2780_remove_slave,
+};
+
+static struct w1_family w1_ds2780_family = {
+	.fid = W1_FAMILY_DS2780,
+	.fops = &w1_ds2780_fops,
+};
+
+static int __init w1_ds2780_init(void)
+{
+	idr_init(&bat_idr);
+	return w1_register_family(&w1_ds2780_family);
+}
+
+static void __exit w1_ds2780_exit(void)
+{
+	w1_unregister_family(&w1_ds2780_family);
+	idr_destroy(&bat_idr);
+}
+
+module_init(w1_ds2780_init);
+module_exit(w1_ds2780_exit);
+
+MODULE_LICENSE("GPL");
+MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
+MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC");
diff --git a/drivers/w1/slaves/w1_ds2780.h b/drivers/w1/slaves/w1_ds2780.h
new file mode 100644
index 000000000000..a1fba79eb1b5
--- /dev/null
+++ b/drivers/w1/slaves/w1_ds2780.h
@@ -0,0 +1,129 @@
+/*
+ * 1-Wire implementation for the ds2780 chip
+ *
+ * Copyright (C) 2010 Indesign, LLC
+ *
+ * Author: Clifton Barnes <cabarnes@indesign-llc.com>
+ *
+ * Based on w1-ds2760 driver
+ *
+ * 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.
+ *
+ */
+
+#ifndef _W1_DS2780_H
+#define _W1_DS2780_H
+
+/* Function commands */
+#define W1_DS2780_READ_DATA		0x69
+#define W1_DS2780_WRITE_DATA		0x6C
+#define W1_DS2780_COPY_DATA		0x48
+#define W1_DS2780_RECALL_DATA		0xB8
+#define W1_DS2780_LOCK			0x6A
+
+/* Register map */
+/* Register 0x00 Reserved */
+#define DS2780_STATUS_REG		0x01
+#define DS2780_RAAC_MSB_REG		0x02
+#define DS2780_RAAC_LSB_REG		0x03
+#define DS2780_RSAC_MSB_REG		0x04
+#define DS2780_RSAC_LSB_REG		0x05
+#define DS2780_RARC_REG			0x06
+#define DS2780_RSRC_REG			0x07
+#define DS2780_IAVG_MSB_REG		0x08
+#define DS2780_IAVG_LSB_REG		0x09
+#define DS2780_TEMP_MSB_REG		0x0A
+#define DS2780_TEMP_LSB_REG		0x0B
+#define DS2780_VOLT_MSB_REG		0x0C
+#define DS2780_VOLT_LSB_REG		0x0D
+#define DS2780_CURRENT_MSB_REG		0x0E
+#define DS2780_CURRENT_LSB_REG		0x0F
+#define DS2780_ACR_MSB_REG		0x10
+#define DS2780_ACR_LSB_REG		0x11
+#define DS2780_ACRL_MSB_REG		0x12
+#define DS2780_ACRL_LSB_REG		0x13
+#define DS2780_AS_REG			0x14
+#define DS2780_SFR_REG			0x15
+#define DS2780_FULL_MSB_REG		0x16
+#define DS2780_FULL_LSB_REG		0x17
+#define DS2780_AE_MSB_REG		0x18
+#define DS2780_AE_LSB_REG		0x19
+#define DS2780_SE_MSB_REG		0x1A
+#define DS2780_SE_LSB_REG		0x1B
+/* Register 0x1C - 0x1E Reserved */
+#define DS2780_EEPROM_REG		0x1F
+#define DS2780_EEPROM_BLOCK0_START	0x20
+/* Register 0x20 - 0x2F User EEPROM */
+#define DS2780_EEPROM_BLOCK0_END	0x2F
+/* Register 0x30 - 0x5F Reserved */
+#define DS2780_EEPROM_BLOCK1_START	0x60
+#define DS2780_CONTROL_REG		0x60
+#define DS2780_AB_REG			0x61
+#define DS2780_AC_MSB_REG		0x62
+#define DS2780_AC_LSB_REG		0x63
+#define DS2780_VCHG_REG			0x64
+#define DS2780_IMIN_REG			0x65
+#define DS2780_VAE_REG			0x66
+#define DS2780_IAE_REG			0x67
+#define DS2780_AE_40_REG		0x68
+#define DS2780_RSNSP_REG		0x69
+#define DS2780_FULL_40_MSB_REG		0x6A
+#define DS2780_FULL_40_LSB_REG		0x6B
+#define DS2780_FULL_3040_SLOPE_REG	0x6C
+#define DS2780_FULL_2030_SLOPE_REG	0x6D
+#define DS2780_FULL_1020_SLOPE_REG	0x6E
+#define DS2780_FULL_0010_SLOPE_REG	0x6F
+#define DS2780_AE_3040_SLOPE_REG	0x70
+#define DS2780_AE_2030_SLOPE_REG	0x71
+#define DS2780_AE_1020_SLOPE_REG	0x72
+#define DS2780_AE_0010_SLOPE_REG	0x73
+#define DS2780_SE_3040_SLOPE_REG	0x74
+#define DS2780_SE_2030_SLOPE_REG	0x75
+#define DS2780_SE_1020_SLOPE_REG	0x76
+#define DS2780_SE_0010_SLOPE_REG	0x77
+#define DS2780_RSGAIN_MSB_REG		0x78
+#define DS2780_RSGAIN_LSB_REG		0x79
+#define DS2780_RSTC_REG			0x7A
+#define DS2780_FRSGAIN_MSB_REG		0x7B
+#define DS2780_FRSGAIN_LSB_REG		0x7C
+#define DS2780_EEPROM_BLOCK1_END	0x7C
+/* Register 0x7D - 0xFF Reserved */
+
+/* Number of valid register addresses */
+#define DS2780_DATA_SIZE		0x80
+
+/* Status register bits */
+#define DS2780_STATUS_REG_CHGTF		(1 << 7)
+#define DS2780_STATUS_REG_AEF		(1 << 6)
+#define DS2780_STATUS_REG_SEF		(1 << 5)
+#define DS2780_STATUS_REG_LEARNF	(1 << 4)
+/* Bit 3 Reserved */
+#define DS2780_STATUS_REG_UVF		(1 << 2)
+#define DS2780_STATUS_REG_PORF		(1 << 1)
+/* Bit 0 Reserved */
+
+/* Control register bits */
+/* Bit 7 Reserved */
+#define DS2780_CONTROL_REG_UVEN		(1 << 6)
+#define DS2780_CONTROL_REG_PMOD		(1 << 5)
+#define DS2780_CONTROL_REG_RNAOP	(1 << 4)
+/* Bit 0 - 3 Reserved */
+
+/* Special feature register bits */
+/* Bit 1 - 7 Reserved */
+#define DS2780_SFR_REG_PIOSC		(1 << 0)
+
+/* EEPROM register bits */
+#define DS2780_EEPROM_REG_EEC		(1 << 7)
+#define DS2780_EEPROM_REG_LOCK		(1 << 6)
+/* Bit 2 - 6 Reserved */
+#define DS2780_EEPROM_REG_BL1		(1 << 1)
+#define DS2780_EEPROM_REG_BL0		(1 << 0)
+
+extern int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,
+			int io);
+extern int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd);
+
+#endif /* !_W1_DS2780_H */