1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * m62332.c - Support for Mitsubishi m62332 DAC
4 *
5 * Copyright (c) 2014 Dmitry Eremin-Solenikov
6 *
7 * Based on max517 driver:
8 * Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
9 */
10
11 #include <linux/module.h>
12 #include <linux/slab.h>
13 #include <linux/i2c.h>
14 #include <linux/err.h>
15
16 #include <linux/iio/iio.h>
17 #include <linux/iio/driver.h>
18
19 #include <linux/regulator/consumer.h>
20
21 #define M62332_CHANNELS 2
22
23 struct m62332_data {
24 struct i2c_client *client;
25 struct regulator *vcc;
26 struct mutex mutex;
27 u8 raw[M62332_CHANNELS];
28 u8 save[M62332_CHANNELS];
29 };
30
m62332_set_value(struct iio_dev * indio_dev,u8 val,int channel)31 static int m62332_set_value(struct iio_dev *indio_dev, u8 val, int channel)
32 {
33 struct m62332_data *data = iio_priv(indio_dev);
34 struct i2c_client *client = data->client;
35 u8 outbuf[2];
36 int res;
37
38 if (val == data->raw[channel])
39 return 0;
40
41 outbuf[0] = channel;
42 outbuf[1] = val;
43
44 mutex_lock(&data->mutex);
45
46 if (val) {
47 res = regulator_enable(data->vcc);
48 if (res)
49 goto out;
50 }
51
52 res = i2c_master_send(client, outbuf, ARRAY_SIZE(outbuf));
53 if (res >= 0 && res != ARRAY_SIZE(outbuf))
54 res = -EIO;
55 if (res < 0)
56 goto out;
57
58 data->raw[channel] = val;
59
60 if (!val)
61 regulator_disable(data->vcc);
62
63 mutex_unlock(&data->mutex);
64
65 return 0;
66
67 out:
68 mutex_unlock(&data->mutex);
69
70 return res;
71 }
72
m62332_read_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int * val,int * val2,long mask)73 static int m62332_read_raw(struct iio_dev *indio_dev,
74 struct iio_chan_spec const *chan,
75 int *val,
76 int *val2,
77 long mask)
78 {
79 struct m62332_data *data = iio_priv(indio_dev);
80 int ret;
81
82 switch (mask) {
83 case IIO_CHAN_INFO_SCALE:
84 /* Corresponds to Vref / 2^(bits) */
85 ret = regulator_get_voltage(data->vcc);
86 if (ret < 0)
87 return ret;
88
89 *val = ret / 1000; /* mV */
90 *val2 = 8;
91
92 return IIO_VAL_FRACTIONAL_LOG2;
93 case IIO_CHAN_INFO_RAW:
94 *val = data->raw[chan->channel];
95
96 return IIO_VAL_INT;
97 case IIO_CHAN_INFO_OFFSET:
98 *val = 1;
99
100 return IIO_VAL_INT;
101 default:
102 break;
103 }
104
105 return -EINVAL;
106 }
107
m62332_write_raw(struct iio_dev * indio_dev,struct iio_chan_spec const * chan,int val,int val2,long mask)108 static int m62332_write_raw(struct iio_dev *indio_dev,
109 struct iio_chan_spec const *chan, int val, int val2,
110 long mask)
111 {
112 switch (mask) {
113 case IIO_CHAN_INFO_RAW:
114 if (val < 0 || val > 255)
115 return -EINVAL;
116
117 return m62332_set_value(indio_dev, val, chan->channel);
118 default:
119 break;
120 }
121
122 return -EINVAL;
123 }
124
m62332_suspend(struct device * dev)125 static int m62332_suspend(struct device *dev)
126 {
127 struct i2c_client *client = to_i2c_client(dev);
128 struct iio_dev *indio_dev = i2c_get_clientdata(client);
129 struct m62332_data *data = iio_priv(indio_dev);
130 int ret;
131
132 data->save[0] = data->raw[0];
133 data->save[1] = data->raw[1];
134
135 ret = m62332_set_value(indio_dev, 0, 0);
136 if (ret < 0)
137 return ret;
138
139 return m62332_set_value(indio_dev, 0, 1);
140 }
141
m62332_resume(struct device * dev)142 static int m62332_resume(struct device *dev)
143 {
144 struct i2c_client *client = to_i2c_client(dev);
145 struct iio_dev *indio_dev = i2c_get_clientdata(client);
146 struct m62332_data *data = iio_priv(indio_dev);
147 int ret;
148
149 ret = m62332_set_value(indio_dev, data->save[0], 0);
150 if (ret < 0)
151 return ret;
152
153 return m62332_set_value(indio_dev, data->save[1], 1);
154 }
155
156 static DEFINE_SIMPLE_DEV_PM_OPS(m62332_pm_ops, m62332_suspend, m62332_resume);
157
158 static const struct iio_info m62332_info = {
159 .read_raw = m62332_read_raw,
160 .write_raw = m62332_write_raw,
161 };
162
163 #define M62332_CHANNEL(chan) { \
164 .type = IIO_VOLTAGE, \
165 .indexed = 1, \
166 .output = 1, \
167 .channel = (chan), \
168 .datasheet_name = "CH" #chan, \
169 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
170 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \
171 BIT(IIO_CHAN_INFO_OFFSET), \
172 }
173
174 static const struct iio_chan_spec m62332_channels[M62332_CHANNELS] = {
175 M62332_CHANNEL(0),
176 M62332_CHANNEL(1)
177 };
178
m62332_probe(struct i2c_client * client,const struct i2c_device_id * id)179 static int m62332_probe(struct i2c_client *client,
180 const struct i2c_device_id *id)
181 {
182 struct m62332_data *data;
183 struct iio_dev *indio_dev;
184 int ret;
185
186 indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
187 if (!indio_dev)
188 return -ENOMEM;
189
190 data = iio_priv(indio_dev);
191 i2c_set_clientdata(client, indio_dev);
192 data->client = client;
193
194 mutex_init(&data->mutex);
195
196 data->vcc = devm_regulator_get(&client->dev, "VCC");
197 if (IS_ERR(data->vcc))
198 return PTR_ERR(data->vcc);
199
200 indio_dev->num_channels = ARRAY_SIZE(m62332_channels);
201 indio_dev->channels = m62332_channels;
202 indio_dev->modes = INDIO_DIRECT_MODE;
203 indio_dev->info = &m62332_info;
204
205 ret = iio_map_array_register(indio_dev, client->dev.platform_data);
206 if (ret < 0)
207 return ret;
208
209 ret = iio_device_register(indio_dev);
210 if (ret < 0)
211 goto err;
212
213 return 0;
214
215 err:
216 iio_map_array_unregister(indio_dev);
217
218 return ret;
219 }
220
m62332_remove(struct i2c_client * client)221 static void m62332_remove(struct i2c_client *client)
222 {
223 struct iio_dev *indio_dev = i2c_get_clientdata(client);
224
225 iio_device_unregister(indio_dev);
226 iio_map_array_unregister(indio_dev);
227 m62332_set_value(indio_dev, 0, 0);
228 m62332_set_value(indio_dev, 0, 1);
229 }
230
231 static const struct i2c_device_id m62332_id[] = {
232 { "m62332", },
233 { }
234 };
235 MODULE_DEVICE_TABLE(i2c, m62332_id);
236
237 static struct i2c_driver m62332_driver = {
238 .driver = {
239 .name = "m62332",
240 .pm = pm_sleep_ptr(&m62332_pm_ops),
241 },
242 .probe = m62332_probe,
243 .remove = m62332_remove,
244 .id_table = m62332_id,
245 };
246 module_i2c_driver(m62332_driver);
247
248 MODULE_AUTHOR("Dmitry Eremin-Solenikov");
249 MODULE_DESCRIPTION("M62332 8-bit DAC");
250 MODULE_LICENSE("GPL v2");
251