xref: /kernel/linux/linux-6.6/drivers/iio/dac/max517.c (revision 62306a36) 
1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 *  max517.c - Support for Maxim MAX517, MAX518 and MAX519
4 *
5 *  Copyright (C) 2010, 2011 Roland Stigge <stigge@antcom.de>
6 */
7
8#include <linux/module.h>
9#include <linux/slab.h>
10#include <linux/jiffies.h>
11#include <linux/i2c.h>
12#include <linux/err.h>
13
14#include <linux/iio/iio.h>
15#include <linux/iio/sysfs.h>
16#include <linux/iio/dac/max517.h>
17
18#define MAX517_DRV_NAME	"max517"
19
20/* Commands */
21#define COMMAND_CHANNEL0	0x00
22#define COMMAND_CHANNEL1	0x01 /* for MAX518 and MAX519 */
23#define COMMAND_PD		0x08 /* Power Down */
24
25enum max517_device_ids {
26	ID_MAX517,
27	ID_MAX518,
28	ID_MAX519,
29	ID_MAX520,
30	ID_MAX521,
31};
32
33struct max517_data {
34	struct i2c_client	*client;
35	unsigned short		vref_mv[8];
36};
37
38/*
39 * channel: bit 0: channel 1
40 *          bit 1: channel 2
41 * (this way, it's possible to set both channels at once)
42 */
43static int max517_set_value(struct iio_dev *indio_dev,
44	long val, int channel)
45{
46	struct max517_data *data = iio_priv(indio_dev);
47	struct i2c_client *client = data->client;
48	u8 outbuf[2];
49	int res;
50
51	if (val < 0 || val > 255)
52		return -EINVAL;
53
54	outbuf[0] = channel;
55	outbuf[1] = val;
56
57	res = i2c_master_send(client, outbuf, 2);
58	if (res < 0)
59		return res;
60	else if (res != 2)
61		return -EIO;
62	else
63		return 0;
64}
65
66static int max517_read_raw(struct iio_dev *indio_dev,
67			   struct iio_chan_spec const *chan,
68			   int *val,
69			   int *val2,
70			   long m)
71{
72	struct max517_data *data = iio_priv(indio_dev);
73
74	switch (m) {
75	case IIO_CHAN_INFO_SCALE:
76		/* Corresponds to Vref / 2^(bits) */
77		*val = data->vref_mv[chan->channel];
78		*val2 = 8;
79		return IIO_VAL_FRACTIONAL_LOG2;
80	default:
81		break;
82	}
83	return -EINVAL;
84}
85
86static int max517_write_raw(struct iio_dev *indio_dev,
87	struct iio_chan_spec const *chan, int val, int val2, long mask)
88{
89	int ret;
90
91	switch (mask) {
92	case IIO_CHAN_INFO_RAW:
93		ret = max517_set_value(indio_dev, val, chan->channel);
94		break;
95	default:
96		ret = -EINVAL;
97		break;
98	}
99
100	return ret;
101}
102
103static int max517_suspend(struct device *dev)
104{
105	u8 outbuf = COMMAND_PD;
106
107	return i2c_master_send(to_i2c_client(dev), &outbuf, 1);
108}
109
110static int max517_resume(struct device *dev)
111{
112	u8 outbuf = 0;
113
114	return i2c_master_send(to_i2c_client(dev), &outbuf, 1);
115}
116
117static DEFINE_SIMPLE_DEV_PM_OPS(max517_pm_ops, max517_suspend, max517_resume);
118
119static const struct iio_info max517_info = {
120	.read_raw = max517_read_raw,
121	.write_raw = max517_write_raw,
122};
123
124#define MAX517_CHANNEL(chan) {				\
125	.type = IIO_VOLTAGE,				\
126	.indexed = 1,					\
127	.output = 1,					\
128	.channel = (chan),				\
129	.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) |	\
130	BIT(IIO_CHAN_INFO_SCALE),			\
131}
132
133static const struct iio_chan_spec max517_channels[] = {
134	MAX517_CHANNEL(0),
135	MAX517_CHANNEL(1),
136	MAX517_CHANNEL(2),
137	MAX517_CHANNEL(3),
138	MAX517_CHANNEL(4),
139	MAX517_CHANNEL(5),
140	MAX517_CHANNEL(6),
141	MAX517_CHANNEL(7),
142};
143
144static int max517_probe(struct i2c_client *client)
145{
146	const struct i2c_device_id *id = i2c_client_get_device_id(client);
147	struct max517_data *data;
148	struct iio_dev *indio_dev;
149	struct max517_platform_data *platform_data = client->dev.platform_data;
150	int chan;
151
152	indio_dev = devm_iio_device_alloc(&client->dev, sizeof(*data));
153	if (!indio_dev)
154		return -ENOMEM;
155	data = iio_priv(indio_dev);
156	data->client = client;
157
158	switch (id->driver_data) {
159	case ID_MAX521:
160		indio_dev->num_channels = 8;
161		break;
162	case ID_MAX520:
163		indio_dev->num_channels = 4;
164		break;
165	case ID_MAX519:
166	case ID_MAX518:
167		indio_dev->num_channels = 2;
168		break;
169	default:  /* single channel for MAX517 */
170		indio_dev->num_channels = 1;
171		break;
172	}
173	indio_dev->channels = max517_channels;
174	indio_dev->modes = INDIO_DIRECT_MODE;
175	indio_dev->info = &max517_info;
176
177	/*
178	 * Reference voltage on MAX518 and default is 5V, else take vref_mv
179	 * from platform_data
180	 */
181	for (chan = 0; chan < indio_dev->num_channels; chan++) {
182		if (id->driver_data == ID_MAX518 || !platform_data)
183			data->vref_mv[chan] = 5000; /* mV */
184		else
185			data->vref_mv[chan] = platform_data->vref_mv[chan];
186	}
187
188	return devm_iio_device_register(&client->dev, indio_dev);
189}
190
191static const struct i2c_device_id max517_id[] = {
192	{ "max517", ID_MAX517 },
193	{ "max518", ID_MAX518 },
194	{ "max519", ID_MAX519 },
195	{ "max520", ID_MAX520 },
196	{ "max521", ID_MAX521 },
197	{ }
198};
199MODULE_DEVICE_TABLE(i2c, max517_id);
200
201static struct i2c_driver max517_driver = {
202	.driver = {
203		.name	= MAX517_DRV_NAME,
204		.pm	= pm_sleep_ptr(&max517_pm_ops),
205	},
206	.probe		= max517_probe,
207	.id_table	= max517_id,
208};
209module_i2c_driver(max517_driver);
210
211MODULE_AUTHOR("Roland Stigge <stigge@antcom.de>");
212MODULE_DESCRIPTION("MAX517/518/519/520/521 8-bit DAC");
213MODULE_LICENSE("GPL");
214