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