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 | |
26 | static 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 | |
51 | int 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(lock: &sl->master->bus_mutex); |
65 | |
66 | return ret; |
67 | } |
68 | EXPORT_SYMBOL(w1_ds2780_io); |
69 | |
70 | int 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(lock: &sl->master->bus_mutex); |
85 | return 0; |
86 | } |
87 | EXPORT_SYMBOL(w1_ds2780_eeprom_cmd); |
88 | |
89 | static 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 | |
98 | static BIN_ATTR_RO(w1_slave, DS2780_DATA_SIZE); |
99 | |
100 | static struct bin_attribute *w1_ds2780_bin_attrs[] = { |
101 | &bin_attr_w1_slave, |
102 | NULL, |
103 | }; |
104 | |
105 | static const struct attribute_group w1_ds2780_group = { |
106 | .bin_attrs = w1_ds2780_bin_attrs, |
107 | }; |
108 | |
109 | static const struct attribute_group *w1_ds2780_groups[] = { |
110 | &w1_ds2780_group, |
111 | NULL, |
112 | }; |
113 | |
114 | static int w1_ds2780_add_slave(struct w1_slave *sl) |
115 | { |
116 | int ret; |
117 | struct platform_device *pdev; |
118 | |
119 | pdev = platform_device_alloc(name: "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(dev: &sl->dev, data: pdev); |
129 | |
130 | return 0; |
131 | |
132 | pdev_add_failed: |
133 | platform_device_put(pdev); |
134 | |
135 | return ret; |
136 | } |
137 | |
138 | static void w1_ds2780_remove_slave(struct w1_slave *sl) |
139 | { |
140 | struct platform_device *pdev = dev_get_drvdata(dev: &sl->dev); |
141 | |
142 | platform_device_unregister(pdev); |
143 | } |
144 | |
145 | static 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 | |
151 | static struct w1_family w1_ds2780_family = { |
152 | .fid = W1_FAMILY_DS2780, |
153 | .fops = &w1_ds2780_fops, |
154 | }; |
155 | module_w1_family(w1_ds2780_family); |
156 | |
157 | MODULE_AUTHOR("Clifton Barnes <cabarnes@indesign-llc.com>" ); |
158 | MODULE_DESCRIPTION("1-wire Driver for Maxim/Dallas DS2780 Stand-Alone Fuel Gauge IC" ); |
159 | MODULE_LICENSE("GPL" ); |
160 | MODULE_ALIAS("w1-family-" __stringify(W1_FAMILY_DS2780)); |
161 | |