[linux.git] / drivers / hwmon / ltc4245.c

/*
 * Driver for Linear Technology LTC4245 I2C Multiple Supply Hot Swap Controller
 *
 * Copyright (C) 2008 Ira W. Snyder <[email protected]>
 *
 * 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_GPIOADC1		= 0x1c,
	LTC4245_GPIOADC2		= 0x1d,
	LTC4245_GPIOADC3		= 0x1e,
};

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[0x0f];
};

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 0x1f */
		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_GPIOADC1:
	case LTC4245_GPIOADC2:
	case LTC4245_GPIOADC3:
		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_GPIOADC1);
LTC4245_VOLTAGE(in10_input,			LTC4245_GPIOADC2);
LTC4245_VOLTAGE(in11_input,			LTC4245_GPIOADC3);

/* 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_in10_input.dev_attr.attr,
	&sensor_dev_attr_in11_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 <[email protected]>");
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 <[email protected]>
	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,
	48	LTC4245_GPIOADC1 = 0x1c,
	49	LTC4245_GPIOADC2 = 0x1d,
	50	LTC4245_GPIOADC3 = 0x1e,
	51	};
	52
	53	struct ltc4245_data {
	54	struct device *hwmon_dev;
	55
	56	struct mutex update_lock;
	57	bool valid;
	58	unsigned long last_updated; /* in jiffies */
	59
	60	/* Control registers */
	61	u8 cregs[0x08];
	62
	63	/* Voltage registers */
	64	u8 vregs[0x0f];
	65	};
	66
	67	static struct ltc4245_data ltc4245_update_device(struct device dev)
	68	{
	69	struct i2c_client *client = to_i2c_client(dev);
	70	struct ltc4245_data *data = i2c_get_clientdata(client);
	71	s32 val;
	72	int i;
	73
	74	mutex_lock(&data->update_lock);
	75
	76	if (time_after(jiffies, data->last_updated + HZ) \|\| !data->valid) {
	77
	78	dev_dbg(&client->dev, "Starting ltc4245 update\n");
	79
	80	/* Read control registers -- 0x00 to 0x07 */
	81	for (i = 0; i < ARRAY_SIZE(data->cregs); i++) {
	82	val = i2c_smbus_read_byte_data(client, i);
	83	if (unlikely(val < 0))
	84	data->cregs[i] = 0;
	85	else
	86	data->cregs[i] = val;
	87	}
	88
89	/* Read voltage registers -- 0x10 to 0x1f */
90	for (i = 0; i < ARRAY_SIZE(data->vregs); i++) {
91	val = i2c_smbus_read_byte_data(client, i+0x10);
92	if (unlikely(val < 0))
93	data->vregs[i] = 0;
94	else
95	data->vregs[i] = val;
96	}
97
98	data->last_updated = jiffies;
99	data->valid = 1;
100	}
101
102	mutex_unlock(&data->update_lock);
103
104	return data;
105	}
106
107	/* Return the voltage from the given register in millivolts */
108	static int ltc4245_get_voltage(struct device *dev, u8 reg)
109	{
110	struct ltc4245_data *data = ltc4245_update_device(dev);
111	const u8 regval = data->vregs[reg - 0x10];
112	u32 voltage = 0;
113
114	switch (reg) {
115	case LTC4245_12VIN:
116	case LTC4245_12VOUT:
117	voltage = regval * 55;
118	break;
119	case LTC4245_5VIN:
120	case LTC4245_5VOUT:
121	voltage = regval * 22;
122	break;
123	case LTC4245_3VIN:
124	case LTC4245_3VOUT:
125	voltage = regval * 15;
126	break;
127	case LTC4245_VEEIN:
128	case LTC4245_VEEOUT:
129	voltage = regval * -55;
130	break;
131	case LTC4245_GPIOADC1:
132	case LTC4245_GPIOADC2:
133	case LTC4245_GPIOADC3:
134	voltage = regval * 10;
135	break;
136	default:
137	/* If we get here, the developer messed up */
138	WARN_ON_ONCE(1);
139	break;
140	}
141
142	return voltage;
143	}
144
145	/* Return the current in the given sense register in milliAmperes */
146	static unsigned int ltc4245_get_current(struct device *dev, u8 reg)
147	{
148	struct ltc4245_data *data = ltc4245_update_device(dev);
149	const u8 regval = data->vregs[reg - 0x10];
150	unsigned int voltage;
151	unsigned int curr;
152
153	/* The strange looking conversions that follow are fixed-point
154	* math, since we cannot do floating point in the kernel.
155	*
156	* Step 1: convert sense register to microVolts
157	* Step 2: convert voltage to milliAmperes
158	*
159	* If you play around with the V=IR equation, you come up with
160	* the following: X uV / Y mOhm == Z mA
161	*
162	* With the resistors that are fractions of a milliOhm, we multiply
163	* the voltage and resistance by 10, to shift the decimal point.
164	* Now we can use the normal division operator again.
165	*/
166
167	switch (reg) {
168	case LTC4245_12VSENSE:
169	voltage = regval * 250; /* voltage in uV */
170	curr = voltage / 50; /* sense resistor 50 mOhm */
171	break;
172	case LTC4245_5VSENSE:
173	voltage = regval * 125; /* voltage in uV */
174	curr = (voltage * 10) / 35; /* sense resistor 3.5 mOhm */
175	break;
176	case LTC4245_3VSENSE:
177	voltage = regval * 125; /* voltage in uV */
178	curr = (voltage * 10) / 25; /* sense resistor 2.5 mOhm */
179	break;
180	case LTC4245_VEESENSE:
181	voltage = regval * 250; /* voltage in uV */
182	curr = voltage / 100; /* sense resistor 100 mOhm */
183	break;
184	default:
185	/* If we get here, the developer messed up */
186	WARN_ON_ONCE(1);
187	curr = 0;
188	break;
189	}
190
191	return curr;
192	}
193
194	static ssize_t ltc4245_show_voltage(struct device *dev,
195	struct device_attribute *da,
196	char *buf)
197	{
198	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
199	const int voltage = ltc4245_get_voltage(dev, attr->index);
200
201	return snprintf(buf, PAGE_SIZE, "%d\n", voltage);
202	}
203
204	static ssize_t ltc4245_show_current(struct device *dev,
205	struct device_attribute *da,
206	char *buf)
207	{
208	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
209	const unsigned int curr = ltc4245_get_current(dev, attr->index);
210
211	return snprintf(buf, PAGE_SIZE, "%u\n", curr);
212	}
213
214	static ssize_t ltc4245_show_power(struct device *dev,
215	struct device_attribute *da,
216	char *buf)
217	{
218	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
219	const unsigned int curr = ltc4245_get_current(dev, attr->index);
220	const int output_voltage = ltc4245_get_voltage(dev, attr->index+1);
221
222	/* current in mA * voltage in mV == power in uW */
223	const unsigned int power = abs(output_voltage * curr);
224
225	return snprintf(buf, PAGE_SIZE, "%u\n", power);
226	}
227
228	static ssize_t ltc4245_show_alarm(struct device *dev,
229	struct device_attribute *da,
230	char *buf)
231	{
232	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da);
233	struct ltc4245_data *data = ltc4245_update_device(dev);
234	const u8 reg = data->cregs[attr->index];
235	const u32 mask = attr->nr;
236
237	return snprintf(buf, PAGE_SIZE, "%u\n", (reg & mask) ? 1 : 0);
238	}
239
240	/* These macros are used below in constructing device attribute objects
241	* for use with sysfs_create_group() to make a sysfs device file
242	* for each register.
243	*/
244
245	#define LTC4245_VOLTAGE(name, ltc4245_cmd_idx) \
246	static SENSOR_DEVICE_ATTR(name, S_IRUGO, \
247	ltc4245_show_voltage, NULL, ltc4245_cmd_idx)
248
249	#define LTC4245_CURRENT(name, ltc4245_cmd_idx) \
250	static SENSOR_DEVICE_ATTR(name, S_IRUGO, \
251	ltc4245_show_current, NULL, ltc4245_cmd_idx)
252
253	#define LTC4245_POWER(name, ltc4245_cmd_idx) \
254	static SENSOR_DEVICE_ATTR(name, S_IRUGO, \
255	ltc4245_show_power, NULL, ltc4245_cmd_idx)
256
257	#define LTC4245_ALARM(name, mask, reg) \
258	static SENSOR_DEVICE_ATTR_2(name, S_IRUGO, \
259	ltc4245_show_alarm, NULL, (mask), reg)
260
261	/* Construct a sensor_device_attribute structure for each register */
262
263	/* Input voltages */
264	LTC4245_VOLTAGE(in1_input, LTC4245_12VIN);
265	LTC4245_VOLTAGE(in2_input, LTC4245_5VIN);
266	LTC4245_VOLTAGE(in3_input, LTC4245_3VIN);
267	LTC4245_VOLTAGE(in4_input, LTC4245_VEEIN);
268
269	/* Input undervoltage alarms */
270	LTC4245_ALARM(in1_min_alarm, (1 << 0), LTC4245_FAULT1);
271	LTC4245_ALARM(in2_min_alarm, (1 << 1), LTC4245_FAULT1);
272	LTC4245_ALARM(in3_min_alarm, (1 << 2), LTC4245_FAULT1);
273	LTC4245_ALARM(in4_min_alarm, (1 << 3), LTC4245_FAULT1);
274
275	/* Currents (via sense resistor) */
276	LTC4245_CURRENT(curr1_input, LTC4245_12VSENSE);
277	LTC4245_CURRENT(curr2_input, LTC4245_5VSENSE);
278	LTC4245_CURRENT(curr3_input, LTC4245_3VSENSE);
279	LTC4245_CURRENT(curr4_input, LTC4245_VEESENSE);
280
281	/* Overcurrent alarms */
282	LTC4245_ALARM(curr1_max_alarm, (1 << 4), LTC4245_FAULT1);
283	LTC4245_ALARM(curr2_max_alarm, (1 << 5), LTC4245_FAULT1);
284	LTC4245_ALARM(curr3_max_alarm, (1 << 6), LTC4245_FAULT1);
285	LTC4245_ALARM(curr4_max_alarm, (1 << 7), LTC4245_FAULT1);
286
287	/* Output voltages */
288	LTC4245_VOLTAGE(in5_input, LTC4245_12VOUT);
289	LTC4245_VOLTAGE(in6_input, LTC4245_5VOUT);
290	LTC4245_VOLTAGE(in7_input, LTC4245_3VOUT);
291	LTC4245_VOLTAGE(in8_input, LTC4245_VEEOUT);
292
293	/* Power Bad alarms */
294	LTC4245_ALARM(in5_min_alarm, (1 << 0), LTC4245_FAULT2);
295	LTC4245_ALARM(in6_min_alarm, (1 << 1), LTC4245_FAULT2);
296	LTC4245_ALARM(in7_min_alarm, (1 << 2), LTC4245_FAULT2);
297	LTC4245_ALARM(in8_min_alarm, (1 << 3), LTC4245_FAULT2);
298
299	/* GPIO voltages */
300	LTC4245_VOLTAGE(in9_input, LTC4245_GPIOADC1);
301	LTC4245_VOLTAGE(in10_input, LTC4245_GPIOADC2);
302	LTC4245_VOLTAGE(in11_input, LTC4245_GPIOADC3);
303
304	/* Power Consumption (virtual) */
305	LTC4245_POWER(power1_input, LTC4245_12VSENSE);
306	LTC4245_POWER(power2_input, LTC4245_5VSENSE);
307	LTC4245_POWER(power3_input, LTC4245_3VSENSE);
308	LTC4245_POWER(power4_input, LTC4245_VEESENSE);
309
310	/* Finally, construct an array of pointers to members of the above objects,
311	* as required for sysfs_create_group()
312	*/
313	static struct attribute *ltc4245_attributes[] = {
314	&sensor_dev_attr_in1_input.dev_attr.attr,
315	&sensor_dev_attr_in2_input.dev_attr.attr,
316	&sensor_dev_attr_in3_input.dev_attr.attr,
317	&sensor_dev_attr_in4_input.dev_attr.attr,
318
319	&sensor_dev_attr_in1_min_alarm.dev_attr.attr,
320	&sensor_dev_attr_in2_min_alarm.dev_attr.attr,
321	&sensor_dev_attr_in3_min_alarm.dev_attr.attr,
322	&sensor_dev_attr_in4_min_alarm.dev_attr.attr,
323
324	&sensor_dev_attr_curr1_input.dev_attr.attr,
325	&sensor_dev_attr_curr2_input.dev_attr.attr,
326	&sensor_dev_attr_curr3_input.dev_attr.attr,
327	&sensor_dev_attr_curr4_input.dev_attr.attr,
328
329	&sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
330	&sensor_dev_attr_curr2_max_alarm.dev_attr.attr,
331	&sensor_dev_attr_curr3_max_alarm.dev_attr.attr,
332	&sensor_dev_attr_curr4_max_alarm.dev_attr.attr,
333
334	&sensor_dev_attr_in5_input.dev_attr.attr,
335	&sensor_dev_attr_in6_input.dev_attr.attr,
336	&sensor_dev_attr_in7_input.dev_attr.attr,
337	&sensor_dev_attr_in8_input.dev_attr.attr,
338
339	&sensor_dev_attr_in5_min_alarm.dev_attr.attr,
340	&sensor_dev_attr_in6_min_alarm.dev_attr.attr,
341	&sensor_dev_attr_in7_min_alarm.dev_attr.attr,
342	&sensor_dev_attr_in8_min_alarm.dev_attr.attr,
343
344	&sensor_dev_attr_in9_input.dev_attr.attr,
345	&sensor_dev_attr_in10_input.dev_attr.attr,
346	&sensor_dev_attr_in11_input.dev_attr.attr,
347
348	&sensor_dev_attr_power1_input.dev_attr.attr,
349	&sensor_dev_attr_power2_input.dev_attr.attr,
350	&sensor_dev_attr_power3_input.dev_attr.attr,
351	&sensor_dev_attr_power4_input.dev_attr.attr,
352
353	NULL,
354	};
355
356	static const struct attribute_group ltc4245_group = {
357	.attrs = ltc4245_attributes,
358	};
359
360	static int ltc4245_probe(struct i2c_client *client,
361	const struct i2c_device_id *id)
362	{
2d2a7cff	363	struct i2c_adapter *adapter = client->adapter;
6e34b187 IS	364	struct ltc4245_data *data;
	365	int ret;
	366
2d2a7cff JD	367	if (!i2c_check_functionality(adapter, I2C_FUNC_SMBUS_BYTE_DATA))
	368	return -ENODEV;
	369
6e34b187 IS	370	data = kzalloc(sizeof(*data), GFP_KERNEL);
	371	if (!data) {
	372	ret = -ENOMEM;
	373	goto out_kzalloc;
	374	}
	375
	376	i2c_set_clientdata(client, data);
	377	mutex_init(&data->update_lock);
	378
	379	/* Initialize the LTC4245 chip */
58f055e5 IS	380	i2c_smbus_write_byte_data(client, LTC4245_FAULT1, 0x00);
58f055e5 IS	381	i2c_smbus_write_byte_data(client, LTC4245_FAULT2, 0x00);
6e34b187 IS	382
	383	/* Register sysfs hooks */
	384	ret = sysfs_create_group(&client->dev.kobj, &ltc4245_group);
	385	if (ret)
	386	goto out_sysfs_create_group;
	387
	388	data->hwmon_dev = hwmon_device_register(&client->dev);
	389	if (IS_ERR(data->hwmon_dev)) {
	390	ret = PTR_ERR(data->hwmon_dev);
	391	goto out_hwmon_device_register;
	392	}
	393
	394	return 0;
	395
	396	out_hwmon_device_register:
	397	sysfs_remove_group(&client->dev.kobj, &ltc4245_group);
	398	out_sysfs_create_group:
	399	kfree(data);
	400	out_kzalloc:
	401	return ret;
	402	}
	403
	404	static int ltc4245_remove(struct i2c_client *client)
	405	{
	406	struct ltc4245_data *data = i2c_get_clientdata(client);
	407
	408	hwmon_device_unregister(data->hwmon_dev);
	409	sysfs_remove_group(&client->dev.kobj, &ltc4245_group);
	410
	411	kfree(data);
	412
	413	return 0;
	414	}
	415
6e34b187	416	static const struct i2c_device_id ltc4245_id[] = {
2d2a7cff	417	{ "ltc4245", 0 },
6e34b187 IS	418	{ }
	419	};
	420	MODULE_DEVICE_TABLE(i2c, ltc4245_id);
	421
	422	/* This is the driver that will be inserted */
	423	static struct i2c_driver ltc4245_driver = {
6e34b187 IS	424	.driver = {
	425	.name = "ltc4245",
	426	},
	427	.probe = ltc4245_probe,
	428	.remove = ltc4245_remove,
	429	.id_table = ltc4245_id,
6e34b187 IS	430	};
	431
	432	static int __init ltc4245_init(void)
	433	{
	434	return i2c_add_driver(&ltc4245_driver);
	435	}
	436
	437	static void __exit ltc4245_exit(void)
	438	{
	439	i2c_del_driver(&ltc4245_driver);
	440	}
	441
	442	MODULE_AUTHOR("Ira W. Snyder <[email protected]>");
	443	MODULE_DESCRIPTION("LTC4245 driver");
	444	MODULE_LICENSE("GPL");
	445
	446	module_init(ltc4245_init);
	447	module_exit(ltc4245_exit);