[net-next-2.6.git] / drivers / hwmon / ltc4245.c

/*
 * Driver for Linear Technology LTC4245 I2C Multiple Supply Hot Swap Controller
 *
 * Copyright (C) 2008 Ira W. Snyder <iws@ovro.caltech.edu>
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This driver is based on the ds1621 and ina209 drivers.
 *
 * Datasheet:
 * http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1006,C1140,P19392,D13517
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/err.h>
#include <linux/slab.h>
#include <linux/i2c.h>
#include <linux/hwmon.h>
#include <linux/hwmon-sysfs.h>

/* Here are names of the chip's registers (a.k.a. commands) */
enum ltc4245_cmd {
	LTC4245_STATUS			= 0x00, /* readonly */
	LTC4245_ALERT			= 0x01,
	LTC4245_CONTROL			= 0x02,
	LTC4245_ON			= 0x03,
	LTC4245_FAULT1			= 0x04,
	LTC4245_FAULT2			= 0x05,
	LTC4245_GPIO			= 0x06,
	LTC4245_ADCADR			= 0x07,

	LTC4245_12VIN			= 0x10,
	LTC4245_12VSENSE		= 0x11,
	LTC4245_12VOUT			= 0x12,
	LTC4245_5VIN			= 0x13,
	LTC4245_5VSENSE			= 0x14,
	LTC4245_5VOUT			= 0x15,
	LTC4245_3VIN			= 0x16,
	LTC4245_3VSENSE			= 0x17,
	LTC4245_3VOUT			= 0x18,
	LTC4245_VEEIN			= 0x19,
	LTC4245_VEESENSE		= 0x1a,
	LTC4245_VEEOUT			= 0x1b,
	LTC4245_GPIOADC			= 0x1c,
};

struct ltc4245_data {
	struct device *hwmon_dev;

	struct mutex update_lock;
	bool valid;
	unsigned long last_updated; /* in jiffies */

	/* Control registers */
	u8 cregs[0x08];

	/* Voltage registers */
	u8 vregs[0x0d];
};

static struct ltc4245_data *ltc4245_update_device(struct device *dev)
{
	struct i2c_client *client = to_i2c_client(dev);
	struct ltc4245_data *data = i2c_get_clientdata(client);
	s32 val;
	int i;

	mutex_lock(&data->update_lock);

	if (time_after(jiffies, data->last_updated + HZ) || !data->valid) {

		dev_dbg(&client->dev, "Starting ltc4245 update\n");

		/* Read control registers -- 0x00 to 0x07 */
		for (i = 0; i < ARRAY_SIZE(data->cregs); i++) {
			val = i2c_smbus_read_byte_data(client, i);
			if (unlikely(val < 0))
				data->cregs[i] = 0;
			else
				data->cregs[i] = val;
		}

		/* Read voltage registers -- 0x10 to 0x1c */
		for (i = 0; i < ARRAY_SIZE(data->vregs); i++) {
			val = i2c_smbus_read_byte_data(client, i+0x10);
			if (unlikely(val < 0))
				data->vregs[i] = 0;
			else
				data->vregs[i] = val;
		}

		data->last_updated = jiffies;
		data->valid = 1;
	}

	mutex_unlock(&data->update_lock);

	return data;
}

/* Return the voltage from the given register in millivolts */
static int ltc4245_get_voltage(struct device *dev, u8 reg)
{
	struct ltc4245_data *data = ltc4245_update_device(dev);
	const u8 regval = data->vregs[reg - 0x10];
	u32 voltage = 0;

	switch (reg) {
	case LTC4245_12VIN:
	case LTC4245_12VOUT:
		voltage = regval * 55;
		break;
	case LTC4245_5VIN:
	case LTC4245_5VOUT:
		voltage = regval * 22;
		break;
	case LTC4245_3VIN:
	case LTC4245_3VOUT:
		voltage = regval * 15;
		break;
	case LTC4245_VEEIN:
	case LTC4245_VEEOUT:
		voltage = regval * -55;
		break;
	case LTC4245_GPIOADC:
		voltage = regval * 10;
		break;
	default:
		/* If we get here, the developer messed up */
		WARN_ON_ONCE(1);
		break;
	}

	return voltage;
}

/* Return the current in the given sense register in milliAmperes */
static unsigned int ltc4245_get_current(struct device *dev, u8 reg)
{
	struct ltc4245_data *data = ltc4245_update_device(dev);
	const u8 regval = data->vregs[reg - 0x10];
	unsigned int voltage;
	unsigned int curr;

	/* The strange looking conversions that follow are fixed-point
	 * math, since we cannot do floating point in the kernel.
	 *
	 * Step 1: convert sense register to microVolts
	 * Step 2: convert voltage to milliAmperes
	 *
	 * If you play around with the V=IR equation, you come up with
	 * the following: X uV / Y mOhm == Z mA
	 *
	 * With the resistors that are fractions of a milliOhm, we multiply
	 * the voltage and resistance by 10, to shift the decimal point.
	 * Now we can use the normal division operator again.
	 */

	switch (reg) {
	case LTC4245_12VSENSE:
		voltage = regval * 250; /* voltage in uV */
		curr = voltage / 50; /* sense resistor 50 mOhm */
		break;
	case LTC4245_5VSENSE:
		voltage = regval * 125; /* voltage in uV */
		curr = (voltage * 10) / 35; /* sense resistor 3.5 mOhm */
		break;
	case LTC4245_3VSENSE:
		voltage = regval * 125; /* voltage in uV */
		curr = (voltage * 10) / 25; /* sense resistor 2.5 mOhm */
		break;
	case LTC4245_VEESENSE:
		voltage = regval * 250; /* voltage in uV */
		curr = voltage / 100; /* sense resistor 100 mOhm */
		break;
	default:
		/* If we get here, the developer messed up */
		WARN_ON_ONCE(1);
		curr = 0;
		break;
	}

	return curr;
}

static ssize_t ltc4245_show_voltage(struct device *dev,
				    struct device_attribute *da,
				    char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	const int voltage = ltc4245_get_voltage(dev, attr->index);

	return snprintf(buf, PAGE_SIZE, "%d\n", voltage);
}

static ssize_t ltc4245_show_current(struct device *dev,
				    struct device_attribute *da,
				    char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	const unsigned int curr = ltc4245_get_current(dev, attr->index);

	return snprintf(buf, PAGE_SIZE, "%u\n", curr);
}

static ssize_t ltc4245_show_power(struct device *dev,
				  struct device_attribute *da,
				  char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	const unsigned int curr = ltc4245_get_current(dev, attr->index);
	const int output_voltage = ltc4245_get_voltage(dev, attr->index+1);

	/* current in mA * voltage in mV == power in uW */
	const unsigned int power = abs(output_voltage * curr);

	return snprintf(buf, PAGE_SIZE, "%u\n", power);
}

static ssize_t ltc4245_show_alarm(struct device *dev,
					  struct device_attribute *da,
					  char *buf)
{
	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da);
	struct ltc4245_data *data = ltc4245_update_device(dev);
	const u8 reg = data->cregs[attr->index];
	const u32 mask = attr->nr;

	return snprintf(buf, PAGE_SIZE, "%u\n", (reg & mask) ? 1 : 0);
}

/* These macros are used below in constructing device attribute objects
 * for use with sysfs_create_group() to make a sysfs device file
 * for each register.
 */

#define LTC4245_VOLTAGE(name, ltc4245_cmd_idx) \
	static SENSOR_DEVICE_ATTR(name, S_IRUGO, \
	ltc4245_show_voltage, NULL, ltc4245_cmd_idx)

#define LTC4245_CURRENT(name, ltc4245_cmd_idx) \
	static SENSOR_DEVICE_ATTR(name, S_IRUGO, \
	ltc4245_show_current, NULL, ltc4245_cmd_idx)

#define LTC4245_POWER(name, ltc4245_cmd_idx) \
	static SENSOR_DEVICE_ATTR(name, S_IRUGO, \
	ltc4245_show_power, NULL, ltc4245_cmd_idx)

#define LTC4245_ALARM(name, mask, reg) \
	static SENSOR_DEVICE_ATTR_2(name, S_IRUGO, \
	ltc4245_show_alarm, NULL, (mask), reg)

/* Construct a sensor_device_attribute structure for each register */

/* Input voltages */
LTC4245_VOLTAGE(in1_input,			LTC4245_12VIN);
LTC4245_VOLTAGE(in2_input,			LTC4245_5VIN);
LTC4245_VOLTAGE(in3_input,			LTC4245_3VIN);
LTC4245_VOLTAGE(in4_input,			LTC4245_VEEIN);

/* Input undervoltage alarms */
LTC4245_ALARM(in1_min_alarm,	(1 << 0),	LTC4245_FAULT1);
LTC4245_ALARM(in2_min_alarm,	(1 << 1),	LTC4245_FAULT1);
LTC4245_ALARM(in3_min_alarm,	(1 << 2),	LTC4245_FAULT1);
LTC4245_ALARM(in4_min_alarm,	(1 << 3),	LTC4245_FAULT1);

/* Currents (via sense resistor) */
LTC4245_CURRENT(curr1_input,			LTC4245_12VSENSE);
LTC4245_CURRENT(curr2_input,			LTC4245_5VSENSE);
LTC4245_CURRENT(curr3_input,			LTC4245_3VSENSE);
LTC4245_CURRENT(curr4_input,			LTC4245_VEESENSE);

/* Overcurrent alarms */
LTC4245_ALARM(curr1_max_alarm,	(1 << 4),	LTC4245_FAULT1);
LTC4245_ALARM(curr2_max_alarm,	(1 << 5),	LTC4245_FAULT1);
LTC4245_ALARM(curr3_max_alarm,	(1 << 6),	LTC4245_FAULT1);
LTC4245_ALARM(curr4_max_alarm,	(1 << 7),	LTC4245_FAULT1);

/* Output voltages */
LTC4245_VOLTAGE(in5_input,			LTC4245_12VOUT);
LTC4245_VOLTAGE(in6_input,			LTC4245_5VOUT);
LTC4245_VOLTAGE(in7_input,			LTC4245_3VOUT);
LTC4245_VOLTAGE(in8_input,			LTC4245_VEEOUT);

/* Power Bad alarms */
LTC4245_ALARM(in5_min_alarm,	(1 << 0),	LTC4245_FAULT2);
LTC4245_ALARM(in6_min_alarm,	(1 << 1),	LTC4245_FAULT2);
LTC4245_ALARM(in7_min_alarm,	(1 << 2),	LTC4245_FAULT2);
LTC4245_ALARM(in8_min_alarm,	(1 << 3),	LTC4245_FAULT2);

/* GPIO voltages */
LTC4245_VOLTAGE(in9_input,			LTC4245_GPIOADC);

/* Power Consumption (virtual) */
LTC4245_POWER(power1_input,			LTC4245_12VSENSE);
LTC4245_POWER(power2_input,			LTC4245_5VSENSE);
LTC4245_POWER(power3_input,			LTC4245_3VSENSE);
LTC4245_POWER(power4_input,			LTC4245_VEESENSE);

/* Finally, construct an array of pointers to members of the above objects,
 * as required for sysfs_create_group()
 */
static struct attribute *ltc4245_attributes[] = {
	&sensor_dev_attr_in1_input.dev_attr.attr,
	&sensor_dev_attr_in2_input.dev_attr.attr,
	&sensor_dev_attr_in3_input.dev_attr.attr,
	&sensor_dev_attr_in4_input.dev_attr.attr,

	&sensor_dev_attr_in1_min_alarm.dev_attr.attr,
	&sensor_dev_attr_in2_min_alarm.dev_attr.attr,
	&sensor_dev_attr_in3_min_alarm.dev_attr.attr,
	&sensor_dev_attr_in4_min_alarm.dev_attr.attr,

	&sensor_dev_attr_curr1_input.dev_attr.attr,
	&sensor_dev_attr_curr2_input.dev_attr.attr,
	&sensor_dev_attr_curr3_input.dev_attr.attr,
	&sensor_dev_attr_curr4_input.dev_attr.attr,

	&sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
	&sensor_dev_attr_curr2_max_alarm.dev_attr.attr,
	&sensor_dev_attr_curr3_max_alarm.dev_attr.attr,
	&sensor_dev_attr_curr4_max_alarm.dev_attr.attr,

	&sensor_dev_attr_in5_input.dev_attr.attr,
	&sensor_dev_attr_in6_input.dev_attr.attr,
	&sensor_dev_attr_in7_input.dev_attr.attr,
	&sensor_dev_attr_in8_input.dev_attr.attr,

	&sensor_dev_attr_in5_min_alarm.dev_attr.attr,
	&sensor_dev_attr_in6_min_alarm.dev_attr.attr,
	&sensor_dev_attr_in7_min_alarm.dev_attr.attr,
	&sensor_dev_attr_in8_min_alarm.dev_attr.attr,

	&sensor_dev_attr_in9_input.dev_attr.attr,

	&sensor_dev_attr_power1_input.dev_attr.attr,
	&sensor_dev_attr_power2_input.dev_attr.attr,
	&sensor_dev_attr_power3_input.dev_attr.attr,
	&sensor_dev_attr_power4_input.dev_attr.attr,

	NULL,
};

static const struct attribute_group ltc4245_group = {
	.attrs = ltc4245_attributes,
};

static int ltc4245_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct i2c_adapter *adapter = client->adapter;
	struct ltc4245_data *data;
	int ret;

	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
		return -ENODEV;

	data = kzalloc(sizeof(*data), GFP_KERNEL);
	if (!data) {
		ret = -ENOMEM;
		goto out_kzalloc;
	}

	i2c_set_clientdata(client, data);
	mutex_init(&data->update_lock);

	/* Initialize the LTC4245 chip */
	i2c_smbus_write_byte_data(client, LTC4245_FAULT1, 0x00);
	i2c_smbus_write_byte_data(client, LTC4245_FAULT2, 0x00);

	/* Register sysfs hooks */
	ret = sysfs_create_group(&client->dev.kobj, &ltc4245_group);
	if (ret)
		goto out_sysfs_create_group;

	data->hwmon_dev = hwmon_device_register(&client->dev);
	if (IS_ERR(data->hwmon_dev)) {
		ret = PTR_ERR(data->hwmon_dev);
		goto out_hwmon_device_register;
	}

	return 0;

out_hwmon_device_register:
	sysfs_remove_group(&client->dev.kobj, &ltc4245_group);
out_sysfs_create_group:
	kfree(data);
out_kzalloc:
	return ret;
}

static int ltc4245_remove(struct i2c_client *client)
{
	struct ltc4245_data *data = i2c_get_clientdata(client);

	hwmon_device_unregister(data->hwmon_dev);
	sysfs_remove_group(&client->dev.kobj, &ltc4245_group);

	kfree(data);

	return 0;
}

static const struct i2c_device_id ltc4245_id[] = {
	{ "ltc4245", 0 },
	{ }
};
MODULE_DEVICE_TABLE(i2c, ltc4245_id);

/* This is the driver that will be inserted */
static struct i2c_driver ltc4245_driver = {
	.driver = {
		.name	= "ltc4245",
	},
	.probe		= ltc4245_probe,
	.remove		= ltc4245_remove,
	.id_table	= ltc4245_id,
};

static int __init ltc4245_init(void)
{
	return i2c_add_driver(&ltc4245_driver);
}

static void __exit ltc4245_exit(void)
{
	i2c_del_driver(&ltc4245_driver);
}

MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
MODULE_DESCRIPTION("LTC4245 driver");
MODULE_LICENSE("GPL");

module_init(ltc4245_init);
module_exit(ltc4245_exit);
Commit	Line	Data
6e34b187 IS	1	/*
	2	* Driver for Linear Technology LTC4245 I2C Multiple Supply Hot Swap Controller
	3	*
	4	* Copyright (C) 2008 Ira W. Snyder <iws@ovro.caltech.edu>
	5	*
	6	* This program is free software; you can redistribute it and/or modify
	7	* it under the terms of the GNU General Public License as published by
	8	* the Free Software Foundation; version 2 of the License.
	9	*
	10	* This driver is based on the ds1621 and ina209 drivers.
	11	*
	12	* Datasheet:
	13	* http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1006,C1140,P19392,D13517
	14	*/
	15
	16	#include <linux/kernel.h>
	17	#include <linux/module.h>
	18	#include <linux/init.h>
	19	#include <linux/err.h>
	20	#include <linux/slab.h>
	21	#include <linux/i2c.h>
	22	#include <linux/hwmon.h>
	23	#include <linux/hwmon-sysfs.h>
	24
6e34b187 IS	25	/* Here are names of the chip's registers (a.k.a. commands) */
	26	enum ltc4245_cmd {
	27	LTC4245_STATUS = 0x00, /* readonly */
	28	LTC4245_ALERT = 0x01,
	29	LTC4245_CONTROL = 0x02,
	30	LTC4245_ON = 0x03,
	31	LTC4245_FAULT1 = 0x04,
	32	LTC4245_FAULT2 = 0x05,
	33	LTC4245_GPIO = 0x06,
	34	LTC4245_ADCADR = 0x07,
	35
	36	LTC4245_12VIN = 0x10,
	37	LTC4245_12VSENSE = 0x11,
	38	LTC4245_12VOUT = 0x12,
	39	LTC4245_5VIN = 0x13,
	40	LTC4245_5VSENSE = 0x14,
	41	LTC4245_5VOUT = 0x15,
	42	LTC4245_3VIN = 0x16,
	43	LTC4245_3VSENSE = 0x17,
	44	LTC4245_3VOUT = 0x18,
	45	LTC4245_VEEIN = 0x19,
	46	LTC4245_VEESENSE = 0x1a,
	47	LTC4245_VEEOUT = 0x1b,
df16dd53	48	LTC4245_GPIOADC = 0x1c,
6e34b187 IS	49	};
	50
	51	struct ltc4245_data {
	52	struct device *hwmon_dev;
	53
	54	struct mutex update_lock;
	55	bool valid;
	56	unsigned long last_updated; /* in jiffies */
	57
	58	/* Control registers */
	59	u8 cregs[0x08];
	60
	61	/* Voltage registers */
df16dd53	62	u8 vregs[0x0d];
6e34b187 IS	63	};
	64
	65	static struct ltc4245_data ltc4245_update_device(struct device dev)
	66	{
	67	struct i2c_client *client = to_i2c_client(dev);
	68	struct ltc4245_data *data = i2c_get_clientdata(client);
	69	s32 val;
	70	int i;
	71
	72	mutex_lock(&data->update_lock);
	73
	74	if (time_after(jiffies, data->last_updated + HZ) \|\| !data->valid) {
	75
	76	dev_dbg(&client->dev, "Starting ltc4245 update\n");
	77
	78	/* Read control registers -- 0x00 to 0x07 */
	79	for (i = 0; i < ARRAY_SIZE(data->cregs); i++) {
	80	val = i2c_smbus_read_byte_data(client, i);
	81	if (unlikely(val < 0))
	82	data->cregs[i] = 0;
	83	else
	84	data->cregs[i] = val;
	85	}
	86
df16dd53	87	/* Read voltage registers -- 0x10 to 0x1c */
6e34b187 IS	88	for (i = 0; i < ARRAY_SIZE(data->vregs); i++) {
	89	val = i2c_smbus_read_byte_data(client, i+0x10);
	90	if (unlikely(val < 0))
	91	data->vregs[i] = 0;
	92	else
	93	data->vregs[i] = val;
	94	}
	95
	96	data->last_updated = jiffies;
	97	data->valid = 1;
	98	}
	99
	100	mutex_unlock(&data->update_lock);
	101
	102	return data;
	103	}
	104
	105	/* Return the voltage from the given register in millivolts */
	106	static int ltc4245_get_voltage(struct device *dev, u8 reg)
	107	{
	108	struct ltc4245_data *data = ltc4245_update_device(dev);
	109	const u8 regval = data->vregs[reg - 0x10];
	110	u32 voltage = 0;
	111
	112	switch (reg) {
	113	case LTC4245_12VIN:
	114	case LTC4245_12VOUT:
	115	voltage = regval * 55;
	116	break;
	117	case LTC4245_5VIN:
	118	case LTC4245_5VOUT:
	119	voltage = regval * 22;
	120	break;
	121	case LTC4245_3VIN:
	122	case LTC4245_3VOUT:
	123	voltage = regval * 15;
	124	break;
	125	case LTC4245_VEEIN:
	126	case LTC4245_VEEOUT:
	127	voltage = regval * -55;
	128	break;
df16dd53	129	case LTC4245_GPIOADC:
6e34b187 IS	130	voltage = regval * 10;
	131	break;
	132	default:
	133	/* If we get here, the developer messed up */
	134	WARN_ON_ONCE(1);
	135	break;
	136	}
	137
	138	return voltage;
	139	}
	140
	141	/* Return the current in the given sense register in milliAmperes */
	142	static unsigned int ltc4245_get_current(struct device *dev, u8 reg)
	143	{
	144	struct ltc4245_data *data = ltc4245_update_device(dev);
	145	const u8 regval = data->vregs[reg - 0x10];
	146	unsigned int voltage;
	147	unsigned int curr;
	148
	149	/* The strange looking conversions that follow are fixed-point
	150	* math, since we cannot do floating point in the kernel.
	151	*
	152	* Step 1: convert sense register to microVolts
	153	* Step 2: convert voltage to milliAmperes
	154	*
	155	* If you play around with the V=IR equation, you come up with
	156	* the following: X uV / Y mOhm == Z mA
	157	*
	158	* With the resistors that are fractions of a milliOhm, we multiply
	159	* the voltage and resistance by 10, to shift the decimal point.
	160	* Now we can use the normal division operator again.
	161	*/
	162
	163	switch (reg) {
	164	case LTC4245_12VSENSE:
	165	voltage = regval * 250; /* voltage in uV */
	166	curr = voltage / 50; /* sense resistor 50 mOhm */
	167	break;
	168	case LTC4245_5VSENSE:
	169	voltage = regval * 125; /* voltage in uV */
	170	curr = (voltage * 10) / 35; /* sense resistor 3.5 mOhm */
	171	break;
	172	case LTC4245_3VSENSE:
	173	voltage = regval * 125; /* voltage in uV */
	174	curr = (voltage * 10) / 25; /* sense resistor 2.5 mOhm */
	175	break;
	176	case LTC4245_VEESENSE:
	177	voltage = regval * 250; /* voltage in uV */
	178	curr = voltage / 100; /* sense resistor 100 mOhm */
	179	break;
	180	default:
	181	/* If we get here, the developer messed up */
	182	WARN_ON_ONCE(1);
	183	curr = 0;
	184	break;
	185	}
	186
	187	return curr;
	188	}
	189
	190	static ssize_t ltc4245_show_voltage(struct device *dev,
	191	struct device_attribute *da,
	192	char *buf)
	193	{
194	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
195	const int voltage = ltc4245_get_voltage(dev, attr->index);
196
197	return snprintf(buf, PAGE_SIZE, "%d\n", voltage);
198	}
199
200	static ssize_t ltc4245_show_current(struct device *dev,
201	struct device_attribute *da,
202	char *buf)
203	{
204	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
205	const unsigned int curr = ltc4245_get_current(dev, attr->index);
206
207	return snprintf(buf, PAGE_SIZE, "%u\n", curr);
208	}
209
210	static ssize_t ltc4245_show_power(struct device *dev,
211	struct device_attribute *da,
212	char *buf)
213	{
214	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
215	const unsigned int curr = ltc4245_get_current(dev, attr->index);
216	const int output_voltage = ltc4245_get_voltage(dev, attr->index+1);
217
218	/* current in mA * voltage in mV == power in uW */
219	const unsigned int power = abs(output_voltage * curr);
220
221	return snprintf(buf, PAGE_SIZE, "%u\n", power);
222	}
223
224	static ssize_t ltc4245_show_alarm(struct device *dev,
225	struct device_attribute *da,
226	char *buf)
227	{
228	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da);
229	struct ltc4245_data *data = ltc4245_update_device(dev);
230	const u8 reg = data->cregs[attr->index];
231	const u32 mask = attr->nr;
232
233	return snprintf(buf, PAGE_SIZE, "%u\n", (reg & mask) ? 1 : 0);
234	}
235
236	/* These macros are used below in constructing device attribute objects
237	* for use with sysfs_create_group() to make a sysfs device file
238	* for each register.
239	*/
240
241	#define LTC4245_VOLTAGE(name, ltc4245_cmd_idx) \
242	static SENSOR_DEVICE_ATTR(name, S_IRUGO, \
243	ltc4245_show_voltage, NULL, ltc4245_cmd_idx)
244
245	#define LTC4245_CURRENT(name, ltc4245_cmd_idx) \
246	static SENSOR_DEVICE_ATTR(name, S_IRUGO, \
247	ltc4245_show_current, NULL, ltc4245_cmd_idx)
248
249	#define LTC4245_POWER(name, ltc4245_cmd_idx) \
250	static SENSOR_DEVICE_ATTR(name, S_IRUGO, \
251	ltc4245_show_power, NULL, ltc4245_cmd_idx)
252
253	#define LTC4245_ALARM(name, mask, reg) \
254	static SENSOR_DEVICE_ATTR_2(name, S_IRUGO, \
255	ltc4245_show_alarm, NULL, (mask), reg)
256
257	/* Construct a sensor_device_attribute structure for each register */
258
259	/* Input voltages */
260	LTC4245_VOLTAGE(in1_input, LTC4245_12VIN);
261	LTC4245_VOLTAGE(in2_input, LTC4245_5VIN);
262	LTC4245_VOLTAGE(in3_input, LTC4245_3VIN);
263	LTC4245_VOLTAGE(in4_input, LTC4245_VEEIN);
264
265	/* Input undervoltage alarms */
266	LTC4245_ALARM(in1_min_alarm, (1 << 0), LTC4245_FAULT1);
267	LTC4245_ALARM(in2_min_alarm, (1 << 1), LTC4245_FAULT1);
268	LTC4245_ALARM(in3_min_alarm, (1 << 2), LTC4245_FAULT1);
269	LTC4245_ALARM(in4_min_alarm, (1 << 3), LTC4245_FAULT1);
270
271	/* Currents (via sense resistor) */
272	LTC4245_CURRENT(curr1_input, LTC4245_12VSENSE);
273	LTC4245_CURRENT(curr2_input, LTC4245_5VSENSE);
274	LTC4245_CURRENT(curr3_input, LTC4245_3VSENSE);
275	LTC4245_CURRENT(curr4_input, LTC4245_VEESENSE);
276
277	/* Overcurrent alarms */
278	LTC4245_ALARM(curr1_max_alarm, (1 << 4), LTC4245_FAULT1);
279	LTC4245_ALARM(curr2_max_alarm, (1 << 5), LTC4245_FAULT1);
280	LTC4245_ALARM(curr3_max_alarm, (1 << 6), LTC4245_FAULT1);
281	LTC4245_ALARM(curr4_max_alarm, (1 << 7), LTC4245_FAULT1);
282
283	/* Output voltages */
284	LTC4245_VOLTAGE(in5_input, LTC4245_12VOUT);
285	LTC4245_VOLTAGE(in6_input, LTC4245_5VOUT);
286	LTC4245_VOLTAGE(in7_input, LTC4245_3VOUT);
287	LTC4245_VOLTAGE(in8_input, LTC4245_VEEOUT);
288
289	/* Power Bad alarms */
290	LTC4245_ALARM(in5_min_alarm, (1 << 0), LTC4245_FAULT2);
291	LTC4245_ALARM(in6_min_alarm, (1 << 1), LTC4245_FAULT2);
292	LTC4245_ALARM(in7_min_alarm, (1 << 2), LTC4245_FAULT2);
293	LTC4245_ALARM(in8_min_alarm, (1 << 3), LTC4245_FAULT2);
294
295	/* GPIO voltages */
df16dd53	296	LTC4245_VOLTAGE(in9_input, LTC4245_GPIOADC);
6e34b187 IS	297
	298	/* Power Consumption (virtual) */
	299	LTC4245_POWER(power1_input, LTC4245_12VSENSE);
	300	LTC4245_POWER(power2_input, LTC4245_5VSENSE);
	301	LTC4245_POWER(power3_input, LTC4245_3VSENSE);
	302	LTC4245_POWER(power4_input, LTC4245_VEESENSE);
	303
	304	/* Finally, construct an array of pointers to members of the above objects,
	305	* as required for sysfs_create_group()
	306	*/
	307	static struct attribute *ltc4245_attributes[] = {
	308	&sensor_dev_attr_in1_input.dev_attr.attr,
	309	&sensor_dev_attr_in2_input.dev_attr.attr,
	310	&sensor_dev_attr_in3_input.dev_attr.attr,
	311	&sensor_dev_attr_in4_input.dev_attr.attr,
	312
	313	&sensor_dev_attr_in1_min_alarm.dev_attr.attr,
	314	&sensor_dev_attr_in2_min_alarm.dev_attr.attr,
	315	&sensor_dev_attr_in3_min_alarm.dev_attr.attr,
	316	&sensor_dev_attr_in4_min_alarm.dev_attr.attr,
	317
	318	&sensor_dev_attr_curr1_input.dev_attr.attr,
	319	&sensor_dev_attr_curr2_input.dev_attr.attr,
	320	&sensor_dev_attr_curr3_input.dev_attr.attr,
	321	&sensor_dev_attr_curr4_input.dev_attr.attr,
	322
	323	&sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
	324	&sensor_dev_attr_curr2_max_alarm.dev_attr.attr,
	325	&sensor_dev_attr_curr3_max_alarm.dev_attr.attr,
	326	&sensor_dev_attr_curr4_max_alarm.dev_attr.attr,
	327
	328	&sensor_dev_attr_in5_input.dev_attr.attr,
	329	&sensor_dev_attr_in6_input.dev_attr.attr,
	330	&sensor_dev_attr_in7_input.dev_attr.attr,
	331	&sensor_dev_attr_in8_input.dev_attr.attr,
	332
	333	&sensor_dev_attr_in5_min_alarm.dev_attr.attr,
	334	&sensor_dev_attr_in6_min_alarm.dev_attr.attr,
	335	&sensor_dev_attr_in7_min_alarm.dev_attr.attr,
	336	&sensor_dev_attr_in8_min_alarm.dev_attr.attr,
	337
	338	&sensor_dev_attr_in9_input.dev_attr.attr,
6e34b187 IS	339
	340	&sensor_dev_attr_power1_input.dev_attr.attr,
	341	&sensor_dev_attr_power2_input.dev_attr.attr,
	342	&sensor_dev_attr_power3_input.dev_attr.attr,
	343	&sensor_dev_attr_power4_input.dev_attr.attr,
	344
	345	NULL,
	346	};
	347
	348	static const struct attribute_group ltc4245_group = {
	349	.attrs = ltc4245_attributes,
	350	};
	351
	352	static int ltc4245_probe(struct i2c_client *client,
	353	const struct i2c_device_id *id)
	354	{
2d2a7cff	355	struct i2c_adapter *adapter = client->adapter;
6e34b187 IS	356	struct ltc4245_data *data;
	357	int ret;
	358
2d2a7cff JD	359	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
	360	return -ENODEV;
	361
6e34b187 IS	362	data = kzalloc(sizeof(*data), GFP_KERNEL);
	363	if (!data) {
	364	ret = -ENOMEM;
	365	goto out_kzalloc;
	366	}
	367
	368	i2c_set_clientdata(client, data);
	369	mutex_init(&data->update_lock);
	370
	371	/* Initialize the LTC4245 chip */
58f055e5 IS	372	i2c_smbus_write_byte_data(client, LTC4245_FAULT1, 0x00);
58f055e5 IS	373	i2c_smbus_write_byte_data(client, LTC4245_FAULT2, 0x00);
6e34b187 IS	374
	375	/* Register sysfs hooks */
	376	ret = sysfs_create_group(&client->dev.kobj, &ltc4245_group);
	377	if (ret)
	378	goto out_sysfs_create_group;
	379
	380	data->hwmon_dev = hwmon_device_register(&client->dev);
	381	if (IS_ERR(data->hwmon_dev)) {
	382	ret = PTR_ERR(data->hwmon_dev);
	383	goto out_hwmon_device_register;
	384	}
	385
	386	return 0;
	387
	388	out_hwmon_device_register:
	389	sysfs_remove_group(&client->dev.kobj, &ltc4245_group);
	390	out_sysfs_create_group:
	391	kfree(data);
	392	out_kzalloc:
	393	return ret;
	394	}
	395
	396	static int ltc4245_remove(struct i2c_client *client)
	397	{
	398	struct ltc4245_data *data = i2c_get_clientdata(client);
	399
	400	hwmon_device_unregister(data->hwmon_dev);
	401	sysfs_remove_group(&client->dev.kobj, &ltc4245_group);
	402
	403	kfree(data);
	404
	405	return 0;
	406	}
	407
6e34b187	408	static const struct i2c_device_id ltc4245_id[] = {
2d2a7cff	409	{ "ltc4245", 0 },
6e34b187 IS	410	{ }
	411	};
	412	MODULE_DEVICE_TABLE(i2c, ltc4245_id);
	413
	414	/* This is the driver that will be inserted */
	415	static struct i2c_driver ltc4245_driver = {
6e34b187 IS	416	.driver = {
	417	.name = "ltc4245",
	418	},
	419	.probe = ltc4245_probe,
	420	.remove = ltc4245_remove,
	421	.id_table = ltc4245_id,
6e34b187 IS	422	};
	423
	424	static int __init ltc4245_init(void)
	425	{
	426	return i2c_add_driver(&ltc4245_driver);
	427	}
	428
	429	static void __exit ltc4245_exit(void)
	430	{
	431	i2c_del_driver(&ltc4245_driver);
	432	}
	433
	434	MODULE_AUTHOR("Ira W. Snyder <iws@ovro.caltech.edu>");
	435	MODULE_DESCRIPTION("LTC4245 driver");
	436	MODULE_LICENSE("GPL");
	437
	438	module_init(ltc4245_init);
	439	module_exit(ltc4245_exit);