1 // SPDX-License-Identifier: GPL-2.0-only
3 * 1-Wire implementation for the ds2781 chip
5 * Author: Renata Sayakhova <renata@oktetlabs.ru>
7 * Based on w1-ds2780 driver
10 #include <linux/kernel.h>
11 #include <linux/module.h>
12 #include <linux/device.h>
13 #include <linux/types.h>
14 #include <linux/platform_device.h>
15 #include <linux/mutex.h>
19 #include "w1_ds2781.h"
21 #define W1_FAMILY_DS2781 0x3D
23 static int w1_ds2781_do_io(struct device
*dev
, char *buf
, int addr
,
26 struct w1_slave
*sl
= container_of(dev
, struct w1_slave
, dev
);
28 if (addr
> DS2781_DATA_SIZE
|| addr
< 0)
31 count
= min_t(int, count
, DS2781_DATA_SIZE
- addr
);
33 if (w1_reset_select_slave(sl
) == 0) {
35 w1_write_8(sl
->master
, W1_DS2781_WRITE_DATA
);
36 w1_write_8(sl
->master
, addr
);
37 w1_write_block(sl
->master
, buf
, count
);
39 w1_write_8(sl
->master
, W1_DS2781_READ_DATA
);
40 w1_write_8(sl
->master
, addr
);
41 count
= w1_read_block(sl
->master
, buf
, count
);
48 int w1_ds2781_io(struct device
*dev
, char *buf
, int addr
, size_t count
,
51 struct w1_slave
*sl
= container_of(dev
, struct w1_slave
, dev
);
57 mutex_lock(&sl
->master
->bus_mutex
);
59 ret
= w1_ds2781_do_io(dev
, buf
, addr
, count
, io
);
61 mutex_unlock(&sl
->master
->bus_mutex
);
65 EXPORT_SYMBOL(w1_ds2781_io
);
67 int w1_ds2781_eeprom_cmd(struct device
*dev
, int addr
, int cmd
)
69 struct w1_slave
*sl
= container_of(dev
, struct w1_slave
, dev
);
74 mutex_lock(&sl
->master
->bus_mutex
);
76 if (w1_reset_select_slave(sl
) == 0) {
77 w1_write_8(sl
->master
, cmd
);
78 w1_write_8(sl
->master
, addr
);
81 mutex_unlock(&sl
->master
->bus_mutex
);
84 EXPORT_SYMBOL(w1_ds2781_eeprom_cmd
);
86 static ssize_t
w1_slave_read(struct file
*filp
, struct kobject
*kobj
,
87 struct bin_attribute
*bin_attr
, char *buf
,
88 loff_t off
, size_t count
)
90 struct device
*dev
= container_of(kobj
, struct device
, kobj
);
91 return w1_ds2781_io(dev
, buf
, off
, count
, 0);
94 static BIN_ATTR_RO(w1_slave
, DS2781_DATA_SIZE
);
96 static struct bin_attribute
*w1_ds2781_bin_attrs
[] = {
101 static const struct attribute_group w1_ds2781_group
= {
102 .bin_attrs
= w1_ds2781_bin_attrs
,
105 static const struct attribute_group
*w1_ds2781_groups
[] = {
110 static int w1_ds2781_add_slave(struct w1_slave
*sl
)
113 struct platform_device
*pdev
;
115 pdev
= platform_device_alloc("ds2781-battery", PLATFORM_DEVID_AUTO
);
118 pdev
->dev
.parent
= &sl
->dev
;
120 ret
= platform_device_add(pdev
);
122 goto pdev_add_failed
;
124 dev_set_drvdata(&sl
->dev
, pdev
);
129 platform_device_put(pdev
);
134 static void w1_ds2781_remove_slave(struct w1_slave
*sl
)
136 struct platform_device
*pdev
= dev_get_drvdata(&sl
->dev
);
138 platform_device_unregister(pdev
);
141 static const struct w1_family_ops w1_ds2781_fops
= {
142 .add_slave
= w1_ds2781_add_slave
,
143 .remove_slave
= w1_ds2781_remove_slave
,
144 .groups
= w1_ds2781_groups
,
147 static struct w1_family w1_ds2781_family
= {
148 .fid
= W1_FAMILY_DS2781
,
149 .fops
= &w1_ds2781_fops
,
151 module_w1_family(w1_ds2781_family
);
153 MODULE_AUTHOR("Renata Sayakhova <renata@oktetlabs.ru>");
154 MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2781 Stand-Alone Fuel Gauge IC");
155 MODULE_LICENSE("GPL");
156 MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2781
));