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471 lines
11 KiB
471 lines
11 KiB
// SPDX-License-Identifier: GPL-2.0-only |
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/* |
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* I2C client/driver for the Maxim/Dallas DS2782 Stand-Alone Fuel Gauge IC |
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* |
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* Copyright (C) 2009 Bluewater Systems Ltd |
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* |
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* Author: Ryan Mallon |
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* |
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* DS2786 added by Yulia Vilensky <[email protected]> |
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* |
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* UEvent sending added by Evgeny Romanov <[email protected]> |
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*/ |
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#include <linux/kernel.h> |
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#include <linux/module.h> |
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#include <linux/types.h> |
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#include <linux/errno.h> |
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#include <linux/swab.h> |
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#include <linux/i2c.h> |
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#include <linux/delay.h> |
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#include <linux/idr.h> |
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#include <linux/power_supply.h> |
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#include <linux/slab.h> |
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#include <linux/ds2782_battery.h> |
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#define DS2782_REG_RARC 0x06 /* Remaining active relative capacity */ |
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#define DS278x_REG_VOLT_MSB 0x0c |
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#define DS278x_REG_TEMP_MSB 0x0a |
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#define DS278x_REG_CURRENT_MSB 0x0e |
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/* EEPROM Block */ |
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#define DS2782_REG_RSNSP 0x69 /* Sense resistor value */ |
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/* Current unit measurement in uA for a 1 milli-ohm sense resistor */ |
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#define DS2782_CURRENT_UNITS 1563 |
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#define DS2786_REG_RARC 0x02 /* Remaining active relative capacity */ |
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#define DS2786_CURRENT_UNITS 25 |
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#define DS278x_DELAY 1000 |
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struct ds278x_info; |
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struct ds278x_battery_ops { |
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int (*get_battery_current)(struct ds278x_info *info, int *current_uA); |
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int (*get_battery_voltage)(struct ds278x_info *info, int *voltage_uV); |
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int (*get_battery_capacity)(struct ds278x_info *info, int *capacity); |
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}; |
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#define to_ds278x_info(x) power_supply_get_drvdata(x) |
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struct ds278x_info { |
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struct i2c_client *client; |
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struct power_supply *battery; |
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struct power_supply_desc battery_desc; |
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const struct ds278x_battery_ops *ops; |
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struct delayed_work bat_work; |
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int id; |
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int rsns; |
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int capacity; |
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int status; /* State Of Charge */ |
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}; |
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static DEFINE_IDR(battery_id); |
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static DEFINE_MUTEX(battery_lock); |
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static inline int ds278x_read_reg(struct ds278x_info *info, int reg, u8 *val) |
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{ |
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int ret; |
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ret = i2c_smbus_read_byte_data(info->client, reg); |
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if (ret < 0) { |
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dev_err(&info->client->dev, "register read failed\n"); |
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return ret; |
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} |
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*val = ret; |
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return 0; |
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} |
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static inline int ds278x_read_reg16(struct ds278x_info *info, int reg_msb, |
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s16 *val) |
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{ |
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int ret; |
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ret = i2c_smbus_read_word_data(info->client, reg_msb); |
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if (ret < 0) { |
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dev_err(&info->client->dev, "register read failed\n"); |
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return ret; |
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} |
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*val = swab16(ret); |
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return 0; |
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} |
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static int ds278x_get_temp(struct ds278x_info *info, int *temp) |
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{ |
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s16 raw; |
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int err; |
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/* |
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* Temperature is measured in units of 0.125 degrees celcius, the |
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* power_supply class measures temperature in tenths of degrees |
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* celsius. The temperature value is stored as a 10 bit number, plus |
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* sign in the upper bits of a 16 bit register. |
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*/ |
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err = ds278x_read_reg16(info, DS278x_REG_TEMP_MSB, &raw); |
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if (err) |
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return err; |
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*temp = ((raw / 32) * 125) / 100; |
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return 0; |
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} |
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static int ds2782_get_current(struct ds278x_info *info, int *current_uA) |
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{ |
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int sense_res; |
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int err; |
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u8 sense_res_raw; |
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s16 raw; |
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/* |
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* The units of measurement for current are dependent on the value of |
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* the sense resistor. |
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*/ |
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err = ds278x_read_reg(info, DS2782_REG_RSNSP, &sense_res_raw); |
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if (err) |
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return err; |
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if (sense_res_raw == 0) { |
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dev_err(&info->client->dev, "sense resistor value is 0\n"); |
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return -ENXIO; |
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} |
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sense_res = 1000 / sense_res_raw; |
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dev_dbg(&info->client->dev, "sense resistor = %d milli-ohms\n", |
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sense_res); |
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err = ds278x_read_reg16(info, DS278x_REG_CURRENT_MSB, &raw); |
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if (err) |
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return err; |
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*current_uA = raw * (DS2782_CURRENT_UNITS / sense_res); |
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return 0; |
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} |
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static int ds2782_get_voltage(struct ds278x_info *info, int *voltage_uV) |
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{ |
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s16 raw; |
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int err; |
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/* |
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* Voltage is measured in units of 4.88mV. The voltage is stored as |
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* a 10-bit number plus sign, in the upper bits of a 16-bit register |
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*/ |
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err = ds278x_read_reg16(info, DS278x_REG_VOLT_MSB, &raw); |
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if (err) |
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return err; |
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*voltage_uV = (raw / 32) * 4800; |
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return 0; |
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} |
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static int ds2782_get_capacity(struct ds278x_info *info, int *capacity) |
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{ |
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int err; |
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u8 raw; |
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err = ds278x_read_reg(info, DS2782_REG_RARC, &raw); |
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if (err) |
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return err; |
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*capacity = raw; |
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return 0; |
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} |
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static int ds2786_get_current(struct ds278x_info *info, int *current_uA) |
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{ |
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int err; |
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s16 raw; |
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err = ds278x_read_reg16(info, DS278x_REG_CURRENT_MSB, &raw); |
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if (err) |
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return err; |
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*current_uA = (raw / 16) * (DS2786_CURRENT_UNITS / info->rsns); |
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return 0; |
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} |
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static int ds2786_get_voltage(struct ds278x_info *info, int *voltage_uV) |
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{ |
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s16 raw; |
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int err; |
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/* |
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* Voltage is measured in units of 1.22mV. The voltage is stored as |
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* a 12-bit number plus sign, in the upper bits of a 16-bit register |
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*/ |
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err = ds278x_read_reg16(info, DS278x_REG_VOLT_MSB, &raw); |
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if (err) |
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return err; |
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*voltage_uV = (raw / 8) * 1220; |
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return 0; |
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} |
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static int ds2786_get_capacity(struct ds278x_info *info, int *capacity) |
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{ |
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int err; |
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u8 raw; |
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err = ds278x_read_reg(info, DS2786_REG_RARC, &raw); |
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if (err) |
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return err; |
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/* Relative capacity is displayed with resolution 0.5 % */ |
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*capacity = raw/2 ; |
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return 0; |
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} |
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static int ds278x_get_status(struct ds278x_info *info, int *status) |
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{ |
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int err; |
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int current_uA; |
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int capacity; |
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err = info->ops->get_battery_current(info, ¤t_uA); |
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if (err) |
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return err; |
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err = info->ops->get_battery_capacity(info, &capacity); |
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if (err) |
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return err; |
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info->capacity = capacity; |
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if (capacity == 100) |
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*status = POWER_SUPPLY_STATUS_FULL; |
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else if (current_uA == 0) |
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*status = POWER_SUPPLY_STATUS_NOT_CHARGING; |
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else if (current_uA < 0) |
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*status = POWER_SUPPLY_STATUS_DISCHARGING; |
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else |
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*status = POWER_SUPPLY_STATUS_CHARGING; |
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return 0; |
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} |
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static int ds278x_battery_get_property(struct power_supply *psy, |
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enum power_supply_property prop, |
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union power_supply_propval *val) |
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{ |
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struct ds278x_info *info = to_ds278x_info(psy); |
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int ret; |
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switch (prop) { |
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case POWER_SUPPLY_PROP_STATUS: |
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ret = ds278x_get_status(info, &val->intval); |
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break; |
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case POWER_SUPPLY_PROP_CAPACITY: |
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ret = info->ops->get_battery_capacity(info, &val->intval); |
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break; |
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case POWER_SUPPLY_PROP_VOLTAGE_NOW: |
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ret = info->ops->get_battery_voltage(info, &val->intval); |
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break; |
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case POWER_SUPPLY_PROP_CURRENT_NOW: |
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ret = info->ops->get_battery_current(info, &val->intval); |
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break; |
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case POWER_SUPPLY_PROP_TEMP: |
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ret = ds278x_get_temp(info, &val->intval); |
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break; |
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default: |
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ret = -EINVAL; |
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} |
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return ret; |
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} |
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static void ds278x_bat_update(struct ds278x_info *info) |
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{ |
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int old_status = info->status; |
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int old_capacity = info->capacity; |
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ds278x_get_status(info, &info->status); |
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if ((old_status != info->status) || (old_capacity != info->capacity)) |
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power_supply_changed(info->battery); |
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} |
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static void ds278x_bat_work(struct work_struct *work) |
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{ |
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struct ds278x_info *info; |
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info = container_of(work, struct ds278x_info, bat_work.work); |
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ds278x_bat_update(info); |
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schedule_delayed_work(&info->bat_work, DS278x_DELAY); |
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} |
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static enum power_supply_property ds278x_battery_props[] = { |
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POWER_SUPPLY_PROP_STATUS, |
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POWER_SUPPLY_PROP_CAPACITY, |
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POWER_SUPPLY_PROP_VOLTAGE_NOW, |
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POWER_SUPPLY_PROP_CURRENT_NOW, |
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POWER_SUPPLY_PROP_TEMP, |
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}; |
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static void ds278x_power_supply_init(struct power_supply_desc *battery) |
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{ |
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battery->type = POWER_SUPPLY_TYPE_BATTERY; |
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battery->properties = ds278x_battery_props; |
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battery->num_properties = ARRAY_SIZE(ds278x_battery_props); |
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battery->get_property = ds278x_battery_get_property; |
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battery->external_power_changed = NULL; |
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} |
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static int ds278x_battery_remove(struct i2c_client *client) |
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{ |
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struct ds278x_info *info = i2c_get_clientdata(client); |
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int id = info->id; |
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power_supply_unregister(info->battery); |
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cancel_delayed_work_sync(&info->bat_work); |
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kfree(info->battery_desc.name); |
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kfree(info); |
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mutex_lock(&battery_lock); |
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idr_remove(&battery_id, id); |
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mutex_unlock(&battery_lock); |
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return 0; |
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} |
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#ifdef CONFIG_PM_SLEEP |
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static int ds278x_suspend(struct device *dev) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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struct ds278x_info *info = i2c_get_clientdata(client); |
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cancel_delayed_work(&info->bat_work); |
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return 0; |
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} |
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static int ds278x_resume(struct device *dev) |
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{ |
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struct i2c_client *client = to_i2c_client(dev); |
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struct ds278x_info *info = i2c_get_clientdata(client); |
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schedule_delayed_work(&info->bat_work, DS278x_DELAY); |
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return 0; |
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} |
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#endif /* CONFIG_PM_SLEEP */ |
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static SIMPLE_DEV_PM_OPS(ds278x_battery_pm_ops, ds278x_suspend, ds278x_resume); |
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enum ds278x_num_id { |
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DS2782 = 0, |
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DS2786, |
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}; |
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static const struct ds278x_battery_ops ds278x_ops[] = { |
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[DS2782] = { |
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.get_battery_current = ds2782_get_current, |
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.get_battery_voltage = ds2782_get_voltage, |
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.get_battery_capacity = ds2782_get_capacity, |
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}, |
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[DS2786] = { |
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.get_battery_current = ds2786_get_current, |
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.get_battery_voltage = ds2786_get_voltage, |
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.get_battery_capacity = ds2786_get_capacity, |
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} |
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}; |
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static int ds278x_battery_probe(struct i2c_client *client, |
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const struct i2c_device_id *id) |
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{ |
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struct ds278x_platform_data *pdata = client->dev.platform_data; |
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struct power_supply_config psy_cfg = {}; |
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struct ds278x_info *info; |
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int ret; |
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int num; |
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/* |
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* ds2786 should have the sense resistor value set |
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* in the platform data |
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*/ |
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if (id->driver_data == DS2786 && !pdata) { |
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dev_err(&client->dev, "missing platform data for ds2786\n"); |
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return -EINVAL; |
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} |
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/* Get an ID for this battery */ |
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mutex_lock(&battery_lock); |
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ret = idr_alloc(&battery_id, client, 0, 0, GFP_KERNEL); |
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mutex_unlock(&battery_lock); |
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if (ret < 0) |
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goto fail_id; |
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num = ret; |
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info = kzalloc(sizeof(*info), GFP_KERNEL); |
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if (!info) { |
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ret = -ENOMEM; |
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goto fail_info; |
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} |
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info->battery_desc.name = kasprintf(GFP_KERNEL, "%s-%d", |
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client->name, num); |
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if (!info->battery_desc.name) { |
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ret = -ENOMEM; |
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goto fail_name; |
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} |
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if (id->driver_data == DS2786) |
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info->rsns = pdata->rsns; |
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i2c_set_clientdata(client, info); |
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info->client = client; |
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info->id = num; |
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info->ops = &ds278x_ops[id->driver_data]; |
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ds278x_power_supply_init(&info->battery_desc); |
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psy_cfg.drv_data = info; |
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info->capacity = 100; |
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info->status = POWER_SUPPLY_STATUS_FULL; |
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INIT_DELAYED_WORK(&info->bat_work, ds278x_bat_work); |
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info->battery = power_supply_register(&client->dev, |
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&info->battery_desc, &psy_cfg); |
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if (IS_ERR(info->battery)) { |
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dev_err(&client->dev, "failed to register battery\n"); |
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ret = PTR_ERR(info->battery); |
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goto fail_register; |
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} else { |
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schedule_delayed_work(&info->bat_work, DS278x_DELAY); |
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} |
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return 0; |
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fail_register: |
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kfree(info->battery_desc.name); |
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fail_name: |
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kfree(info); |
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fail_info: |
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mutex_lock(&battery_lock); |
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idr_remove(&battery_id, num); |
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mutex_unlock(&battery_lock); |
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fail_id: |
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return ret; |
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} |
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static const struct i2c_device_id ds278x_id[] = { |
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{"ds2782", DS2782}, |
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{"ds2786", DS2786}, |
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{}, |
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}; |
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MODULE_DEVICE_TABLE(i2c, ds278x_id); |
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static struct i2c_driver ds278x_battery_driver = { |
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.driver = { |
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.name = "ds2782-battery", |
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.pm = &ds278x_battery_pm_ops, |
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}, |
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.probe = ds278x_battery_probe, |
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.remove = ds278x_battery_remove, |
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.id_table = ds278x_id, |
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}; |
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module_i2c_driver(ds278x_battery_driver); |
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MODULE_AUTHOR("Ryan Mallon"); |
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MODULE_DESCRIPTION("Maxim/Dallas DS2782 Stand-Alone Fuel Gauge IC driver"); |
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MODULE_LICENSE("GPL");
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