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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * 1-Wire implementation for the ds2780 chip4 *5 * Copyright (C) 2010 Indesign, LLC6 *7 * Author: Clifton Barnes <cabarnes@indesign-llc.com>8 *9 * Based on w1-ds2760 driver10 */11 12#include <linux/kernel.h>13#include <linux/module.h>14#include <linux/device.h>15#include <linux/types.h>16#include <linux/platform_device.h>17#include <linux/mutex.h>18#include <linux/idr.h>19 20#include <linux/w1.h>21 22#include "w1_ds2780.h"23 24#define W1_FAMILY_DS2780 0x3225 26static int w1_ds2780_do_io(struct device *dev, char *buf, int addr,27 size_t count, int io)28{29 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);30 31 if (addr > DS2780_DATA_SIZE || addr < 0)32 return 0;33 34 count = min_t(int, count, DS2780_DATA_SIZE - addr);35 36 if (w1_reset_select_slave(sl) == 0) {37 if (io) {38 w1_write_8(sl->master, W1_DS2780_WRITE_DATA);39 w1_write_8(sl->master, addr);40 w1_write_block(sl->master, buf, count);41 } else {42 w1_write_8(sl->master, W1_DS2780_READ_DATA);43 w1_write_8(sl->master, addr);44 count = w1_read_block(sl->master, buf, count);45 }46 }47 48 return count;49}50 51int w1_ds2780_io(struct device *dev, char *buf, int addr, size_t count,52 int io)53{54 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);55 int ret;56 57 if (!dev)58 return -ENODEV;59 60 mutex_lock(&sl->master->bus_mutex);61 62 ret = w1_ds2780_do_io(dev, buf, addr, count, io);63 64 mutex_unlock(&sl->master->bus_mutex);65 66 return ret;67}68EXPORT_SYMBOL(w1_ds2780_io);69 70int w1_ds2780_eeprom_cmd(struct device *dev, int addr, int cmd)71{72 struct w1_slave *sl = container_of(dev, struct w1_slave, dev);73 74 if (!dev)75 return -EINVAL;76 77 mutex_lock(&sl->master->bus_mutex);78 79 if (w1_reset_select_slave(sl) == 0) {80 w1_write_8(sl->master, cmd);81 w1_write_8(sl->master, addr);82 }83 84 mutex_unlock(&sl->master->bus_mutex);85 return 0;86}87EXPORT_SYMBOL(w1_ds2780_eeprom_cmd);88 89static ssize_t w1_slave_read(struct file *filp, struct kobject *kobj,90 struct bin_attribute *bin_attr, char *buf,91 loff_t off, size_t count)92{93 struct device *dev = kobj_to_dev(kobj);94 95 return w1_ds2780_io(dev, buf, off, count, 0);96}97 98static BIN_ATTR_RO(w1_slave, DS2780_DATA_SIZE);99 100static struct bin_attribute *w1_ds2780_bin_attrs[] = {101 &bin_attr_w1_slave,102 NULL,103};104 105static const struct attribute_group w1_ds2780_group = {106 .bin_attrs = w1_ds2780_bin_attrs,107};108 109static const struct attribute_group *w1_ds2780_groups[] = {110 &w1_ds2780_group,111 NULL,112};113 114static int w1_ds2780_add_slave(struct w1_slave *sl)115{116 int ret;117 struct platform_device *pdev;118 119 pdev = platform_device_alloc("ds2780-battery", PLATFORM_DEVID_AUTO);120 if (!pdev)121 return -ENOMEM;122 pdev->dev.parent = &sl->dev;123 124 ret = platform_device_add(pdev);125 if (ret)126 goto pdev_add_failed;127 128 dev_set_drvdata(&sl->dev, pdev);129 130 return 0;131 132pdev_add_failed:133 platform_device_put(pdev);134 135 return ret;136}137 138static void w1_ds2780_remove_slave(struct w1_slave *sl)139{140 struct platform_device *pdev = dev_get_drvdata(&sl->dev);141 142 platform_device_unregister(pdev);143}144 145static const struct w1_family_ops w1_ds2780_fops = {146 .add_slave = w1_ds2780_add_slave,147 .remove_slave = w1_ds2780_remove_slave,148 .groups = w1_ds2780_groups,149};150 151static struct w1_family w1_ds2780_family = {152 .fid = W1_FAMILY_DS2780,153 .fops = &w1_ds2780_fops,154};155module_w1_family(w1_ds2780_family);156 157MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");158MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC");159MODULE_LICENSE("GPL");160MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2780));161