Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
5510e62a | 2 | /* |
592758b1 | 3 | * mcp3021.c - driver for Microchip MCP3021 and MCP3221 |
5510e62a XX |
4 | * |
5 | * Copyright (C) 2008-2009, 2012 Freescale Semiconductor, Inc. | |
6 | * Author: Mingkai Hu <Mingkai.hu@freescale.com> | |
8b662f38 | 7 | * Reworked by Sven Schuchmann <schuchmann@schleissheimer.de> |
f4dc811c | 8 | * DT support added by Clemens Gruber <clemens.gruber@pqgruber.com> |
5510e62a XX |
9 | * |
10 | * This driver export the value of analog input voltage to sysfs, the | |
11 | * voltage unit is mV. Through the sysfs interface, lm-sensors tool | |
12 | * can also display the input voltage. | |
5510e62a XX |
13 | */ |
14 | ||
15 | #include <linux/kernel.h> | |
16 | #include <linux/module.h> | |
17 | #include <linux/hwmon.h> | |
18 | #include <linux/slab.h> | |
19 | #include <linux/i2c.h> | |
20 | #include <linux/err.h> | |
21 | #include <linux/device.h> | |
f4dc811c CG |
22 | #include <linux/of.h> |
23 | #include <linux/of_device.h> | |
5510e62a | 24 | |
f4dc811c CG |
25 | /* Vdd / reference voltage in millivolt */ |
26 | #define MCP3021_VDD_REF_MAX 5500 | |
27 | #define MCP3021_VDD_REF_MIN 2700 | |
28 | #define MCP3021_VDD_REF_DEFAULT 3300 | |
5510e62a XX |
29 | |
30 | /* output format */ | |
31 | #define MCP3021_SAR_SHIFT 2 | |
32 | #define MCP3021_SAR_MASK 0x3ff | |
5510e62a | 33 | #define MCP3021_OUTPUT_RES 10 /* 10-bit resolution */ |
5510e62a | 34 | |
592758b1 SS |
35 | #define MCP3221_SAR_SHIFT 0 |
36 | #define MCP3221_SAR_MASK 0xfff | |
37 | #define MCP3221_OUTPUT_RES 12 /* 12-bit resolution */ | |
592758b1 | 38 | |
8b662f38 | 39 | enum chips { |
592758b1 SS |
40 | mcp3021, |
41 | mcp3221 | |
8b662f38 | 42 | }; |
592758b1 | 43 | |
5510e62a XX |
44 | /* |
45 | * Client data (each client gets its own) | |
46 | */ | |
47 | struct mcp3021_data { | |
48 | struct device *hwmon_dev; | |
f4dc811c | 49 | u32 vdd; /* supply and reference voltage in millivolt */ |
8b662f38 SS |
50 | u16 sar_shift; |
51 | u16 sar_mask; | |
52 | u8 output_res; | |
5510e62a XX |
53 | }; |
54 | ||
55 | static int mcp3021_read16(struct i2c_client *client) | |
56 | { | |
8b662f38 | 57 | struct mcp3021_data *data = i2c_get_clientdata(client); |
5510e62a XX |
58 | int ret; |
59 | u16 reg; | |
60 | __be16 buf; | |
61 | ||
62 | ret = i2c_master_recv(client, (char *)&buf, 2); | |
63 | if (ret < 0) | |
64 | return ret; | |
65 | if (ret != 2) | |
66 | return -EIO; | |
67 | ||
68 | /* The output code of the MCP3021 is transmitted with MSB first. */ | |
69 | reg = be16_to_cpu(buf); | |
70 | ||
71 | /* | |
72 | * The ten-bit output code is composed of the lower 4-bit of the | |
73 | * first byte and the upper 6-bit of the second byte. | |
74 | */ | |
8b662f38 | 75 | reg = (reg >> data->sar_shift) & data->sar_mask; |
5510e62a XX |
76 | |
77 | return reg; | |
78 | } | |
79 | ||
8b662f38 | 80 | static inline u16 volts_from_reg(struct mcp3021_data *data, u16 val) |
5510e62a | 81 | { |
347d7e45 | 82 | return DIV_ROUND_CLOSEST(data->vdd * val, 1 << data->output_res); |
5510e62a XX |
83 | } |
84 | ||
5c2f0dd5 JL |
85 | static ssize_t in0_input_show(struct device *dev, |
86 | struct device_attribute *attr, char *buf) | |
5510e62a XX |
87 | { |
88 | struct i2c_client *client = to_i2c_client(dev); | |
89 | struct mcp3021_data *data = i2c_get_clientdata(client); | |
90 | int reg, in_input; | |
91 | ||
92 | reg = mcp3021_read16(client); | |
93 | if (reg < 0) | |
94 | return reg; | |
95 | ||
8b662f38 SS |
96 | in_input = volts_from_reg(data, reg); |
97 | ||
5510e62a XX |
98 | return sprintf(buf, "%d\n", in_input); |
99 | } | |
100 | ||
5c2f0dd5 | 101 | static DEVICE_ATTR_RO(in0_input); |
5510e62a XX |
102 | |
103 | static int mcp3021_probe(struct i2c_client *client, | |
104 | const struct i2c_device_id *id) | |
105 | { | |
106 | int err; | |
107 | struct mcp3021_data *data = NULL; | |
f4dc811c | 108 | struct device_node *np = client->dev.of_node; |
5510e62a XX |
109 | |
110 | if (!i2c_check_functionality(client->adapter, I2C_FUNC_I2C)) | |
111 | return -ENODEV; | |
112 | ||
79831fd4 GR |
113 | data = devm_kzalloc(&client->dev, sizeof(struct mcp3021_data), |
114 | GFP_KERNEL); | |
5510e62a XX |
115 | if (!data) |
116 | return -ENOMEM; | |
117 | ||
118 | i2c_set_clientdata(client, data); | |
119 | ||
f4dc811c CG |
120 | if (np) { |
121 | if (!of_property_read_u32(np, "reference-voltage-microvolt", | |
122 | &data->vdd)) | |
123 | data->vdd /= 1000; | |
124 | else | |
125 | data->vdd = MCP3021_VDD_REF_DEFAULT; | |
126 | } else { | |
127 | u32 *pdata = dev_get_platdata(&client->dev); | |
128 | ||
129 | if (pdata) | |
130 | data->vdd = *pdata; | |
131 | else | |
132 | data->vdd = MCP3021_VDD_REF_DEFAULT; | |
133 | } | |
134 | ||
8b662f38 SS |
135 | switch (id->driver_data) { |
136 | case mcp3021: | |
137 | data->sar_shift = MCP3021_SAR_SHIFT; | |
138 | data->sar_mask = MCP3021_SAR_MASK; | |
139 | data->output_res = MCP3021_OUTPUT_RES; | |
8b662f38 | 140 | break; |
592758b1 SS |
141 | |
142 | case mcp3221: | |
143 | data->sar_shift = MCP3221_SAR_SHIFT; | |
144 | data->sar_mask = MCP3221_SAR_MASK; | |
145 | data->output_res = MCP3221_OUTPUT_RES; | |
592758b1 | 146 | break; |
8b662f38 SS |
147 | } |
148 | ||
f4dc811c CG |
149 | if (data->vdd > MCP3021_VDD_REF_MAX || data->vdd < MCP3021_VDD_REF_MIN) |
150 | return -EINVAL; | |
5510e62a XX |
151 | |
152 | err = sysfs_create_file(&client->dev.kobj, &dev_attr_in0_input.attr); | |
153 | if (err) | |
79831fd4 | 154 | return err; |
5510e62a XX |
155 | |
156 | data->hwmon_dev = hwmon_device_register(&client->dev); | |
157 | if (IS_ERR(data->hwmon_dev)) { | |
158 | err = PTR_ERR(data->hwmon_dev); | |
159 | goto exit_remove; | |
160 | } | |
161 | ||
162 | return 0; | |
163 | ||
164 | exit_remove: | |
165 | sysfs_remove_file(&client->dev.kobj, &dev_attr_in0_input.attr); | |
5510e62a XX |
166 | return err; |
167 | } | |
168 | ||
169 | static int mcp3021_remove(struct i2c_client *client) | |
170 | { | |
171 | struct mcp3021_data *data = i2c_get_clientdata(client); | |
172 | ||
173 | hwmon_device_unregister(data->hwmon_dev); | |
174 | sysfs_remove_file(&client->dev.kobj, &dev_attr_in0_input.attr); | |
5510e62a XX |
175 | |
176 | return 0; | |
177 | } | |
178 | ||
179 | static const struct i2c_device_id mcp3021_id[] = { | |
8b662f38 | 180 | { "mcp3021", mcp3021 }, |
592758b1 | 181 | { "mcp3221", mcp3221 }, |
5510e62a XX |
182 | { } |
183 | }; | |
184 | MODULE_DEVICE_TABLE(i2c, mcp3021_id); | |
185 | ||
f4dc811c CG |
186 | #ifdef CONFIG_OF |
187 | static const struct of_device_id of_mcp3021_match[] = { | |
188 | { .compatible = "microchip,mcp3021", .data = (void *)mcp3021 }, | |
189 | { .compatible = "microchip,mcp3221", .data = (void *)mcp3221 }, | |
190 | { } | |
191 | }; | |
192 | MODULE_DEVICE_TABLE(of, of_mcp3021_match); | |
193 | #endif | |
194 | ||
5510e62a XX |
195 | static struct i2c_driver mcp3021_driver = { |
196 | .driver = { | |
197 | .name = "mcp3021", | |
f4dc811c | 198 | .of_match_table = of_match_ptr(of_mcp3021_match), |
5510e62a XX |
199 | }, |
200 | .probe = mcp3021_probe, | |
201 | .remove = mcp3021_remove, | |
202 | .id_table = mcp3021_id, | |
203 | }; | |
204 | ||
205 | module_i2c_driver(mcp3021_driver); | |
206 | ||
207 | MODULE_AUTHOR("Mingkai Hu <Mingkai.hu@freescale.com>"); | |
592758b1 | 208 | MODULE_DESCRIPTION("Microchip MCP3021/MCP3221 driver"); |
5510e62a | 209 | MODULE_LICENSE("GPL"); |