[linux.git] / drivers / hwmon / ltc4222.c

/*
 * Driver for Linear Technology LTC4222 Dual Hot Swap controller
 *
 * Copyright (c) 2014 Guenter Roeck
 *
 * 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; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 */

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

/* chip registers */

#define LTC4222_CONTROL1	0xd0
#define LTC4222_ALERT1		0xd1
#define LTC4222_STATUS1		0xd2
#define LTC4222_FAULT1		0xd3
#define LTC4222_CONTROL2	0xd4
#define LTC4222_ALERT2		0xd5
#define LTC4222_STATUS2		0xd6
#define LTC4222_FAULT2		0xd7
#define LTC4222_SOURCE1		0xd8
#define LTC4222_SOURCE2		0xda
#define LTC4222_ADIN1		0xdc
#define LTC4222_ADIN2		0xde
#define LTC4222_SENSE1		0xe0
#define LTC4222_SENSE2		0xe2
#define LTC4222_ADC_CONTROL	0xe4

/*
 * Fault register bits
 */
#define FAULT_OV	BIT(0)
#define FAULT_UV	BIT(1)
#define FAULT_OC	BIT(2)
#define FAULT_POWER_BAD	BIT(3)
#define FAULT_FET_BAD	BIT(5)

/* Return the voltage from the given register in mV or mA */
static int ltc4222_get_value(struct device *dev, u8 reg)
{
	struct regmap *regmap = dev_get_drvdata(dev);
	unsigned int val;
	u8 buf[2];
	int ret;

	ret = regmap_bulk_read(regmap, reg, buf, 2);
	if (ret < 0)
		return ret;

	val = ((buf[0] << 8) + buf[1]) >> 6;

	switch (reg) {
	case LTC4222_ADIN1:
	case LTC4222_ADIN2:
		/* 1.25 mV resolution. Convert to mV. */
		val = DIV_ROUND_CLOSEST(val * 5, 4);
		break;
	case LTC4222_SOURCE1:
	case LTC4222_SOURCE2:
		/* 31.25 mV resolution. Convert to mV. */
		val = DIV_ROUND_CLOSEST(val * 125, 4);
		break;
	case LTC4222_SENSE1:
	case LTC4222_SENSE2:
		/*
		 * 62.5 uV resolution. Convert to current as measured with
		 * an 1 mOhm sense resistor, in mA. If a different sense
		 * resistor is installed, calculate the actual current by
		 * dividing the reported current by the sense resistor value
		 * in mOhm.
		 */
		val = DIV_ROUND_CLOSEST(val * 125, 2);
		break;
	default:
		return -EINVAL;
	}
	return val;
}

static ssize_t ltc4222_show_value(struct device *dev,
				  struct device_attribute *da, char *buf)
{
	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
	int value;

	value = ltc4222_get_value(dev, attr->index);
	if (value < 0)
		return value;
	return snprintf(buf, PAGE_SIZE, "%d\n", value);
}

static ssize_t ltc4222_show_bool(struct device *dev,
				 struct device_attribute *da, char *buf)
{
	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da);
	struct regmap *regmap = dev_get_drvdata(dev);
	unsigned int fault;
	int ret;

	ret = regmap_read(regmap, attr->nr, &fault);
	if (ret < 0)
		return ret;
	fault &= attr->index;
	if (fault)		/* Clear reported faults in chip register */
		regmap_update_bits(regmap, attr->nr, attr->index, 0);

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

/* Voltages */
static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc4222_show_value, NULL,
			  LTC4222_SOURCE1);
static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc4222_show_value, NULL,
			  LTC4222_ADIN1);
static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ltc4222_show_value, NULL,
			  LTC4222_SOURCE2);
static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ltc4222_show_value, NULL,
			  LTC4222_ADIN2);

/*
 * Voltage alarms
 * UV/OV faults are associated with the input voltage, and power bad and fet
 * faults are associated with the output voltage.
 */
static SENSOR_DEVICE_ATTR_2(in1_min_alarm, S_IRUGO, ltc4222_show_bool, NULL,
			    LTC4222_FAULT1, FAULT_UV);
static SENSOR_DEVICE_ATTR_2(in1_max_alarm, S_IRUGO, ltc4222_show_bool, NULL,
			    LTC4222_FAULT1, FAULT_OV);
static SENSOR_DEVICE_ATTR_2(in2_alarm, S_IRUGO, ltc4222_show_bool, NULL,
			    LTC4222_FAULT1, FAULT_POWER_BAD | FAULT_FET_BAD);

static SENSOR_DEVICE_ATTR_2(in3_min_alarm, S_IRUGO, ltc4222_show_bool, NULL,
			    LTC4222_FAULT2, FAULT_UV);
static SENSOR_DEVICE_ATTR_2(in3_max_alarm, S_IRUGO, ltc4222_show_bool, NULL,
			    LTC4222_FAULT2, FAULT_OV);
static SENSOR_DEVICE_ATTR_2(in4_alarm, S_IRUGO, ltc4222_show_bool, NULL,
			    LTC4222_FAULT2, FAULT_POWER_BAD | FAULT_FET_BAD);

/* Current (via sense resistor) */
static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc4222_show_value, NULL,
			  LTC4222_SENSE1);
static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO, ltc4222_show_value, NULL,
			  LTC4222_SENSE2);

/* Overcurrent alarm */
static SENSOR_DEVICE_ATTR_2(curr1_max_alarm, S_IRUGO, ltc4222_show_bool, NULL,
			    LTC4222_FAULT1, FAULT_OC);
static SENSOR_DEVICE_ATTR_2(curr2_max_alarm, S_IRUGO, ltc4222_show_bool, NULL,
			    LTC4222_FAULT2, FAULT_OC);

static struct attribute *ltc4222_attrs[] = {
	&sensor_dev_attr_in1_input.dev_attr.attr,
	&sensor_dev_attr_in1_min_alarm.dev_attr.attr,
	&sensor_dev_attr_in1_max_alarm.dev_attr.attr,
	&sensor_dev_attr_in2_input.dev_attr.attr,
	&sensor_dev_attr_in2_alarm.dev_attr.attr,
	&sensor_dev_attr_in3_input.dev_attr.attr,
	&sensor_dev_attr_in3_min_alarm.dev_attr.attr,
	&sensor_dev_attr_in3_max_alarm.dev_attr.attr,
	&sensor_dev_attr_in4_input.dev_attr.attr,
	&sensor_dev_attr_in4_alarm.dev_attr.attr,

	&sensor_dev_attr_curr1_input.dev_attr.attr,
	&sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
	&sensor_dev_attr_curr2_input.dev_attr.attr,
	&sensor_dev_attr_curr2_max_alarm.dev_attr.attr,

	NULL,
};
ATTRIBUTE_GROUPS(ltc4222);

static const struct regmap_config ltc4222_regmap_config = {
	.reg_bits = 8,
	.val_bits = 8,
	.max_register = LTC4222_ADC_CONTROL,
};

static int ltc4222_probe(struct i2c_client *client,
			 const struct i2c_device_id *id)
{
	struct device *dev = &client->dev;
	struct device *hwmon_dev;
	struct regmap *regmap;

	regmap = devm_regmap_init_i2c(client, &ltc4222_regmap_config);
	if (IS_ERR(regmap)) {
		dev_err(dev, "failed to allocate register map\n");
		return PTR_ERR(regmap);
	}

	/* Clear faults */
	regmap_write(regmap, LTC4222_FAULT1, 0x00);
	regmap_write(regmap, LTC4222_FAULT2, 0x00);

	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
							   regmap,
							   ltc4222_groups);
	return PTR_ERR_OR_ZERO(hwmon_dev);
}

static const struct i2c_device_id ltc4222_id[] = {
	{"ltc4222", 0},
	{ }
};

MODULE_DEVICE_TABLE(i2c, ltc4222_id);

static struct i2c_driver ltc4222_driver = {
	.driver = {
		   .name = "ltc4222",
		   },
	.probe = ltc4222_probe,
	.id_table = ltc4222_id,
};

module_i2c_driver(ltc4222_driver);

MODULE_AUTHOR("Guenter Roeck <[email protected]>");
MODULE_DESCRIPTION("LTC4222 driver");
MODULE_LICENSE("GPL");
Commit	Line	Data
79ffe859 GR	1	/*
	2	* Driver for Linear Technology LTC4222 Dual Hot Swap controller
	3	*
	4	* Copyright (c) 2014 Guenter Roeck
	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; either version 2 of the License, or
	9	* (at your option) any later version.
	10	*
	11	* This program is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	* GNU General Public License for more details.
	15	*/
	16
	17	#include <linux/kernel.h>
	18	#include <linux/module.h>
	19	#include <linux/err.h>
	20	#include <linux/slab.h>
	21	#include <linux/bitops.h>
	22	#include <linux/i2c.h>
	23	#include <linux/hwmon.h>
	24	#include <linux/hwmon-sysfs.h>
	25	#include <linux/jiffies.h>
	26	#include <linux/regmap.h>
	27
	28	/* chip registers */
	29
	30	#define LTC4222_CONTROL1 0xd0
	31	#define LTC4222_ALERT1 0xd1
	32	#define LTC4222_STATUS1 0xd2
	33	#define LTC4222_FAULT1 0xd3
	34	#define LTC4222_CONTROL2 0xd4
	35	#define LTC4222_ALERT2 0xd5
	36	#define LTC4222_STATUS2 0xd6
	37	#define LTC4222_FAULT2 0xd7
	38	#define LTC4222_SOURCE1 0xd8
	39	#define LTC4222_SOURCE2 0xda
	40	#define LTC4222_ADIN1 0xdc
	41	#define LTC4222_ADIN2 0xde
	42	#define LTC4222_SENSE1 0xe0
	43	#define LTC4222_SENSE2 0xe2
	44	#define LTC4222_ADC_CONTROL 0xe4
	45
	46	/*
	47	* Fault register bits
	48	*/
	49	#define FAULT_OV BIT(0)
	50	#define FAULT_UV BIT(1)
	51	#define FAULT_OC BIT(2)
	52	#define FAULT_POWER_BAD BIT(3)
	53	#define FAULT_FET_BAD BIT(5)
	54
	55	/* Return the voltage from the given register in mV or mA */
	56	static int ltc4222_get_value(struct device *dev, u8 reg)
	57	{
	58	struct regmap *regmap = dev_get_drvdata(dev);
	59	unsigned int val;
	60	u8 buf[2];
	61	int ret;
	62
	63	ret = regmap_bulk_read(regmap, reg, buf, 2);
	64	if (ret < 0)
65	return ret;
66
67	val = ((buf[0] << 8) + buf[1]) >> 6;
68
69	switch (reg) {
70	case LTC4222_ADIN1:
71	case LTC4222_ADIN2:
72	/* 1.25 mV resolution. Convert to mV. */
73	val = DIV_ROUND_CLOSEST(val * 5, 4);
74	break;
75	case LTC4222_SOURCE1:
76	case LTC4222_SOURCE2:
77	/* 31.25 mV resolution. Convert to mV. */
78	val = DIV_ROUND_CLOSEST(val * 125, 4);
79	break;
80	case LTC4222_SENSE1:
81	case LTC4222_SENSE2:
82	/*
83	* 62.5 uV resolution. Convert to current as measured with
84	* an 1 mOhm sense resistor, in mA. If a different sense
85	* resistor is installed, calculate the actual current by
86	* dividing the reported current by the sense resistor value
87	* in mOhm.
88	*/
89	val = DIV_ROUND_CLOSEST(val * 125, 2);
90	break;
91	default:
92	return -EINVAL;
93	}
94	return val;
95	}
96
97	static ssize_t ltc4222_show_value(struct device *dev,
98	struct device_attribute da, char buf)
99	{
100	struct sensor_device_attribute *attr = to_sensor_dev_attr(da);
101	int value;
102
103	value = ltc4222_get_value(dev, attr->index);
104	if (value < 0)
105	return value;
106	return snprintf(buf, PAGE_SIZE, "%d\n", value);
107	}
108
109	static ssize_t ltc4222_show_bool(struct device *dev,
110	struct device_attribute da, char buf)
111	{
112	struct sensor_device_attribute_2 *attr = to_sensor_dev_attr_2(da);
113	struct regmap *regmap = dev_get_drvdata(dev);
114	unsigned int fault;
115	int ret;
116
117	ret = regmap_read(regmap, attr->nr, &fault);
118	if (ret < 0)
119	return ret;
120	fault &= attr->index;
121	if (fault) /* Clear reported faults in chip register */
122	regmap_update_bits(regmap, attr->nr, attr->index, 0);
123
124	return snprintf(buf, PAGE_SIZE, "%d\n", !!fault);
125	}
126
127	/* Voltages */
128	static SENSOR_DEVICE_ATTR(in1_input, S_IRUGO, ltc4222_show_value, NULL,
129	LTC4222_SOURCE1);
130	static SENSOR_DEVICE_ATTR(in2_input, S_IRUGO, ltc4222_show_value, NULL,
131	LTC4222_ADIN1);
132	static SENSOR_DEVICE_ATTR(in3_input, S_IRUGO, ltc4222_show_value, NULL,
133	LTC4222_SOURCE2);
134	static SENSOR_DEVICE_ATTR(in4_input, S_IRUGO, ltc4222_show_value, NULL,
135	LTC4222_ADIN2);
136
137	/*
138	* Voltage alarms
139	* UV/OV faults are associated with the input voltage, and power bad and fet
140	* faults are associated with the output voltage.
141	*/
142	static SENSOR_DEVICE_ATTR_2(in1_min_alarm, S_IRUGO, ltc4222_show_bool, NULL,
143	LTC4222_FAULT1, FAULT_UV);
144	static SENSOR_DEVICE_ATTR_2(in1_max_alarm, S_IRUGO, ltc4222_show_bool, NULL,
145	LTC4222_FAULT1, FAULT_OV);
146	static SENSOR_DEVICE_ATTR_2(in2_alarm, S_IRUGO, ltc4222_show_bool, NULL,
147	LTC4222_FAULT1, FAULT_POWER_BAD \| FAULT_FET_BAD);
148
149	static SENSOR_DEVICE_ATTR_2(in3_min_alarm, S_IRUGO, ltc4222_show_bool, NULL,
150	LTC4222_FAULT2, FAULT_UV);
151	static SENSOR_DEVICE_ATTR_2(in3_max_alarm, S_IRUGO, ltc4222_show_bool, NULL,
152	LTC4222_FAULT2, FAULT_OV);
153	static SENSOR_DEVICE_ATTR_2(in4_alarm, S_IRUGO, ltc4222_show_bool, NULL,
154	LTC4222_FAULT2, FAULT_POWER_BAD \| FAULT_FET_BAD);
155
156	/* Current (via sense resistor) */
157	static SENSOR_DEVICE_ATTR(curr1_input, S_IRUGO, ltc4222_show_value, NULL,
158	LTC4222_SENSE1);
159	static SENSOR_DEVICE_ATTR(curr2_input, S_IRUGO, ltc4222_show_value, NULL,
160	LTC4222_SENSE2);
161
162	/* Overcurrent alarm */
163	static SENSOR_DEVICE_ATTR_2(curr1_max_alarm, S_IRUGO, ltc4222_show_bool, NULL,
164	LTC4222_FAULT1, FAULT_OC);
165	static SENSOR_DEVICE_ATTR_2(curr2_max_alarm, S_IRUGO, ltc4222_show_bool, NULL,
166	LTC4222_FAULT2, FAULT_OC);
167
168	static struct attribute *ltc4222_attrs[] = {
169	&sensor_dev_attr_in1_input.dev_attr.attr,
170	&sensor_dev_attr_in1_min_alarm.dev_attr.attr,
171	&sensor_dev_attr_in1_max_alarm.dev_attr.attr,
172	&sensor_dev_attr_in2_input.dev_attr.attr,
173	&sensor_dev_attr_in2_alarm.dev_attr.attr,
174	&sensor_dev_attr_in3_input.dev_attr.attr,
175	&sensor_dev_attr_in3_min_alarm.dev_attr.attr,
176	&sensor_dev_attr_in3_max_alarm.dev_attr.attr,
177	&sensor_dev_attr_in4_input.dev_attr.attr,
178	&sensor_dev_attr_in4_alarm.dev_attr.attr,
179
180	&sensor_dev_attr_curr1_input.dev_attr.attr,
181	&sensor_dev_attr_curr1_max_alarm.dev_attr.attr,
182	&sensor_dev_attr_curr2_input.dev_attr.attr,
183	&sensor_dev_attr_curr2_max_alarm.dev_attr.attr,
184
185	NULL,
186	};
187	ATTRIBUTE_GROUPS(ltc4222);
188
034b44b4	189	static const struct regmap_config ltc4222_regmap_config = {
79ffe859 GR	190	.reg_bits = 8,
	191	.val_bits = 8,
	192	.max_register = LTC4222_ADC_CONTROL,
	193	};
	194
	195	static int ltc4222_probe(struct i2c_client *client,
	196	const struct i2c_device_id *id)
	197	{
	198	struct device *dev = &client->dev;
	199	struct device *hwmon_dev;
	200	struct regmap *regmap;
	201
	202	regmap = devm_regmap_init_i2c(client, &ltc4222_regmap_config);
	203	if (IS_ERR(regmap)) {
	204	dev_err(dev, "failed to allocate register map\n");
	205	return PTR_ERR(regmap);
	206	}
	207
	208	/* Clear faults */
	209	regmap_write(regmap, LTC4222_FAULT1, 0x00);
	210	regmap_write(regmap, LTC4222_FAULT2, 0x00);
	211
	212	hwmon_dev = devm_hwmon_device_register_with_groups(dev, client->name,
	213	regmap,
	214	ltc4222_groups);
	215	return PTR_ERR_OR_ZERO(hwmon_dev);
	216	}
	217
	218	static const struct i2c_device_id ltc4222_id[] = {
	219	{"ltc4222", 0},
	220	{ }
	221	};
	222
	223	MODULE_DEVICE_TABLE(i2c, ltc4222_id);
	224
	225	static struct i2c_driver ltc4222_driver = {
	226	.driver = {
	227	.name = "ltc4222",
	228	},
	229	.probe = ltc4222_probe,
	230	.id_table = ltc4222_id,
	231	};
	232
	233	module_i2c_driver(ltc4222_driver);
	234
	235	MODULE_AUTHOR("Guenter Roeck <[email protected]>");
	236	MODULE_DESCRIPTION("LTC4222 driver");
	237	MODULE_LICENSE("GPL");