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