w1_ds2780.c

  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			     const 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 const BIN_ATTR_RO(w1_slave, DS2780_DATA_SIZE);
 99
100static const struct bin_attribute *const 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));