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 | |
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(regulator: data->vcc); |
48 | if (res) |
49 | goto out; |
50 | } |
51 | |
52 | res = i2c_master_send(client, buf: 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(regulator: data->vcc); |
62 | |
63 | mutex_unlock(lock: &data->mutex); |
64 | |
65 | return 0; |
66 | |
67 | out: |
68 | mutex_unlock(lock: &data->mutex); |
69 | |
70 | return res; |
71 | } |
72 | |
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(regulator: 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 | |
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, channel: chan->channel); |
118 | default: |
119 | break; |
120 | } |
121 | |
122 | return -EINVAL; |
123 | } |
124 | |
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, val: 0, channel: 0); |
136 | if (ret < 0) |
137 | return ret; |
138 | |
139 | return m62332_set_value(indio_dev, val: 0, channel: 1); |
140 | } |
141 | |
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, val: data->save[0], channel: 0); |
150 | if (ret < 0) |
151 | return ret; |
152 | |
153 | return m62332_set_value(indio_dev, val: data->save[1], channel: 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 | |
179 | static int m62332_probe(struct i2c_client *client) |
180 | { |
181 | struct m62332_data *data; |
182 | struct iio_dev *indio_dev; |
183 | int ret; |
184 | |
185 | indio_dev = devm_iio_device_alloc(parent: &client->dev, sizeof_priv: sizeof(*data)); |
186 | if (!indio_dev) |
187 | return -ENOMEM; |
188 | |
189 | data = iio_priv(indio_dev); |
190 | i2c_set_clientdata(client, data: indio_dev); |
191 | data->client = client; |
192 | |
193 | mutex_init(&data->mutex); |
194 | |
195 | data->vcc = devm_regulator_get(dev: &client->dev, id: "VCC" ); |
196 | if (IS_ERR(ptr: data->vcc)) |
197 | return PTR_ERR(ptr: data->vcc); |
198 | |
199 | indio_dev->num_channels = ARRAY_SIZE(m62332_channels); |
200 | indio_dev->channels = m62332_channels; |
201 | indio_dev->modes = INDIO_DIRECT_MODE; |
202 | indio_dev->info = &m62332_info; |
203 | |
204 | ret = iio_map_array_register(indio_dev, map: client->dev.platform_data); |
205 | if (ret < 0) |
206 | return ret; |
207 | |
208 | ret = iio_device_register(indio_dev); |
209 | if (ret < 0) |
210 | goto err; |
211 | |
212 | return 0; |
213 | |
214 | err: |
215 | iio_map_array_unregister(indio_dev); |
216 | |
217 | return ret; |
218 | } |
219 | |
220 | static void m62332_remove(struct i2c_client *client) |
221 | { |
222 | struct iio_dev *indio_dev = i2c_get_clientdata(client); |
223 | |
224 | iio_device_unregister(indio_dev); |
225 | iio_map_array_unregister(indio_dev); |
226 | m62332_set_value(indio_dev, val: 0, channel: 0); |
227 | m62332_set_value(indio_dev, val: 0, channel: 1); |
228 | } |
229 | |
230 | static const struct i2c_device_id m62332_id[] = { |
231 | { "m62332" , }, |
232 | { } |
233 | }; |
234 | MODULE_DEVICE_TABLE(i2c, m62332_id); |
235 | |
236 | static struct i2c_driver m62332_driver = { |
237 | .driver = { |
238 | .name = "m62332" , |
239 | .pm = pm_sleep_ptr(&m62332_pm_ops), |
240 | }, |
241 | .probe = m62332_probe, |
242 | .remove = m62332_remove, |
243 | .id_table = m62332_id, |
244 | }; |
245 | module_i2c_driver(m62332_driver); |
246 | |
247 | MODULE_AUTHOR("Dmitry Eremin-Solenikov" ); |
248 | MODULE_DESCRIPTION("M62332 8-bit DAC" ); |
249 | MODULE_LICENSE("GPL v2" ); |
250 | |