1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
|
// SPDX-License-Identifier: GPL-2.0-only
/*
* MEN 16z188 Analog to Digial Converter
*
* Copyright (C) 2014 MEN Mikroelektronik GmbH (www.men.de)
* Author: Johannes Thumshirn <johannes.thumshirn@men.de>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/mcb.h>
#include <linux/io.h>
#include <linux/iio/iio.h>
#define Z188_ADC_MAX_CHAN 8
#define Z188_ADC_GAIN 0x0700000
#define Z188_MODE_VOLTAGE BIT(27)
#define Z188_CFG_AUTO 0x1
#define Z188_CTRL_REG 0x40
#define ADC_DATA(x) (((x) >> 2) & 0x7ffffc)
#define ADC_OVR(x) ((x) & 0x1)
struct z188_adc {
struct resource *mem;
void __iomem *base;
};
#define Z188_ADC_CHANNEL(idx) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.channel = (idx), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
}
static const struct iio_chan_spec z188_adc_iio_channels[] = {
Z188_ADC_CHANNEL(0),
Z188_ADC_CHANNEL(1),
Z188_ADC_CHANNEL(2),
Z188_ADC_CHANNEL(3),
Z188_ADC_CHANNEL(4),
Z188_ADC_CHANNEL(5),
Z188_ADC_CHANNEL(6),
Z188_ADC_CHANNEL(7),
};
static int z188_iio_read_raw(struct iio_dev *iio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long info)
{
struct z188_adc *adc = iio_priv(iio_dev);
int ret;
u16 tmp;
switch (info) {
case IIO_CHAN_INFO_RAW:
tmp = readw(adc->base + chan->channel * 4);
if (ADC_OVR(tmp)) {
dev_info(&iio_dev->dev,
"Oversampling error on ADC channel %d\n",
chan->channel);
return -EIO;
}
*val = ADC_DATA(tmp);
ret = IIO_VAL_INT;
break;
default:
ret = -EINVAL;
break;
}
return ret;
}
static const struct iio_info z188_adc_info = {
.read_raw = &z188_iio_read_raw,
};
static void men_z188_config_channels(void __iomem *addr)
{
int i;
u32 cfg;
u32 ctl;
ctl = readl(addr + Z188_CTRL_REG);
ctl |= Z188_CFG_AUTO;
writel(ctl, addr + Z188_CTRL_REG);
for (i = 0; i < Z188_ADC_MAX_CHAN; i++) {
cfg = readl(addr + i);
cfg &= ~Z188_ADC_GAIN;
cfg |= Z188_MODE_VOLTAGE;
writel(cfg, addr + i);
}
}
static int men_z188_probe(struct mcb_device *dev,
const struct mcb_device_id *id)
{
struct z188_adc *adc;
struct iio_dev *indio_dev;
struct resource *mem;
int ret;
indio_dev = devm_iio_device_alloc(&dev->dev, sizeof(struct z188_adc));
if (!indio_dev)
return -ENOMEM;
adc = iio_priv(indio_dev);
indio_dev->name = "z188-adc";
indio_dev->info = &z188_adc_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = z188_adc_iio_channels;
indio_dev->num_channels = ARRAY_SIZE(z188_adc_iio_channels);
mem = mcb_request_mem(dev, "z188-adc");
if (IS_ERR(mem))
return PTR_ERR(mem);
adc->base = ioremap(mem->start, resource_size(mem));
if (adc->base == NULL)
goto err;
men_z188_config_channels(adc->base);
adc->mem = mem;
mcb_set_drvdata(dev, indio_dev);
ret = iio_device_register(indio_dev);
if (ret)
goto err_unmap;
return 0;
err_unmap:
iounmap(adc->base);
err:
mcb_release_mem(mem);
return -ENXIO;
}
static void men_z188_remove(struct mcb_device *dev)
{
struct iio_dev *indio_dev = mcb_get_drvdata(dev);
struct z188_adc *adc = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
iounmap(adc->base);
mcb_release_mem(adc->mem);
}
static const struct mcb_device_id men_z188_ids[] = {
{ .device = 0xbc },
{ }
};
MODULE_DEVICE_TABLE(mcb, men_z188_ids);
static struct mcb_driver men_z188_driver = {
.driver = {
.name = "z188-adc",
},
.probe = men_z188_probe,
.remove = men_z188_remove,
.id_table = men_z188_ids,
};
module_mcb_driver(men_z188_driver);
MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>");
MODULE_LICENSE("GPL");
MODULE_DESCRIPTION("IIO ADC driver for MEN 16z188 ADC Core");
MODULE_ALIAS("mcb:16z188");
MODULE_IMPORT_NS(MCB);
|
