| /* |
| * 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_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, <c4245_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, <c4245_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, <c4245_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(<c4245_driver); |
| } |
| |
| static void __exit ltc4245_exit(void) |
| { |
| i2c_del_driver(<c4245_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); |
