cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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w1_ds2780.c (3527B)

      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * 1-Wire implementation for the ds2780 chip
      4 *
      5 * Copyright (C) 2010 Indesign, LLC
      6 *
      7 * Author: Clifton Barnes <cabarnes@indesign-llc.com>
      8 *
      9 * Based on w1-ds2760 driver
     10 */
     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	0x32
     25
     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	return w1_ds2780_io(dev, buf, off, count, 0);
     95}
     96
     97static BIN_ATTR_RO(w1_slave, DS2780_DATA_SIZE);
     98
     99static struct bin_attribute *w1_ds2780_bin_attrs[] = {
    100	&bin_attr_w1_slave,
    101	NULL,
    102};
    103
    104static const struct attribute_group w1_ds2780_group = {
    105	.bin_attrs = w1_ds2780_bin_attrs,
    106};
    107
    108static const struct attribute_group *w1_ds2780_groups[] = {
    109	&w1_ds2780_group,
    110	NULL,
    111};
    112
    113static int w1_ds2780_add_slave(struct w1_slave *sl)
    114{
    115	int ret;
    116	struct platform_device *pdev;
    117
    118	pdev = platform_device_alloc("ds2780-battery", PLATFORM_DEVID_AUTO);
    119	if (!pdev)
    120		return -ENOMEM;
    121	pdev->dev.parent = &sl->dev;
    122
    123	ret = platform_device_add(pdev);
    124	if (ret)
    125		goto pdev_add_failed;
    126
    127	dev_set_drvdata(&sl->dev, pdev);
    128
    129	return 0;
    130
    131pdev_add_failed:
    132	platform_device_put(pdev);
    133
    134	return ret;
    135}
    136
    137static void w1_ds2780_remove_slave(struct w1_slave *sl)
    138{
    139	struct platform_device *pdev = dev_get_drvdata(&sl->dev);
    140
    141	platform_device_unregister(pdev);
    142}
    143
    144static const struct w1_family_ops w1_ds2780_fops = {
    145	.add_slave    = w1_ds2780_add_slave,
    146	.remove_slave = w1_ds2780_remove_slave,
    147	.groups       = w1_ds2780_groups,
    148};
    149
    150static struct w1_family w1_ds2780_family = {
    151	.fid = W1_FAMILY_DS2780,
    152	.fops = &w1_ds2780_fops,
    153};
    154module_w1_family(w1_ds2780_family);
    155
    156MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>");
    157MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC");
    158MODULE_LICENSE("GPL");
    159MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2780));