1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * MEN 16z188 Analog to Digial Converter |
4 | * |
5 | * Copyright (C) 2014 MEN Mikroelektronik GmbH (www.men.de) |
6 | * Author: Johannes Thumshirn <johannes.thumshirn@men.de> |
7 | */ |
8 | |
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 | |
24 | struct 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 | |
36 | static 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 | |
47 | static 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(indio_dev: iio_dev); |
54 | int ret; |
55 | u16 tmp; |
56 | |
57 | switch (info) { |
58 | case IIO_CHAN_INFO_RAW: |
59 | tmp = readw(addr: 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 | |
78 | static const struct iio_info z188_adc_info = { |
79 | .read_raw = &z188_iio_read_raw, |
80 | }; |
81 | |
82 | static void men_z188_config_channels(void __iomem *addr) |
83 | { |
84 | int i; |
85 | u32 cfg; |
86 | u32 ctl; |
87 | |
88 | ctl = readl(addr: addr + Z188_CTRL_REG); |
89 | ctl |= Z188_CFG_AUTO; |
90 | writel(val: ctl, addr: addr + Z188_CTRL_REG); |
91 | |
92 | for (i = 0; i < Z188_ADC_MAX_CHAN; i++) { |
93 | cfg = readl(addr: addr + i); |
94 | cfg &= ~Z188_ADC_GAIN; |
95 | cfg |= Z188_MODE_VOLTAGE; |
96 | writel(val: cfg, addr: addr + i); |
97 | } |
98 | } |
99 | |
100 | static 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 | int ret; |
107 | |
108 | indio_dev = devm_iio_device_alloc(parent: &dev->dev, sizeof_priv: sizeof(struct z188_adc)); |
109 | if (!indio_dev) |
110 | return -ENOMEM; |
111 | |
112 | adc = iio_priv(indio_dev); |
113 | indio_dev->name = "z188-adc" ; |
114 | indio_dev->info = &z188_adc_info; |
115 | indio_dev->modes = INDIO_DIRECT_MODE; |
116 | indio_dev->channels = z188_adc_iio_channels; |
117 | indio_dev->num_channels = ARRAY_SIZE(z188_adc_iio_channels); |
118 | |
119 | mem = mcb_request_mem(dev, name: "z188-adc" ); |
120 | if (IS_ERR(ptr: mem)) |
121 | return PTR_ERR(ptr: mem); |
122 | |
123 | adc->base = ioremap(offset: mem->start, size: resource_size(res: mem)); |
124 | if (adc->base == NULL) |
125 | goto err; |
126 | |
127 | men_z188_config_channels(addr: adc->base); |
128 | |
129 | adc->mem = mem; |
130 | mcb_set_drvdata(dev, data: indio_dev); |
131 | |
132 | ret = iio_device_register(indio_dev); |
133 | if (ret) |
134 | goto err_unmap; |
135 | |
136 | return 0; |
137 | |
138 | err_unmap: |
139 | iounmap(addr: adc->base); |
140 | err: |
141 | mcb_release_mem(mem); |
142 | return -ENXIO; |
143 | } |
144 | |
145 | static void men_z188_remove(struct mcb_device *dev) |
146 | { |
147 | struct iio_dev *indio_dev = mcb_get_drvdata(dev); |
148 | struct z188_adc *adc = iio_priv(indio_dev); |
149 | |
150 | iio_device_unregister(indio_dev); |
151 | iounmap(addr: adc->base); |
152 | mcb_release_mem(mem: adc->mem); |
153 | } |
154 | |
155 | static const struct mcb_device_id men_z188_ids[] = { |
156 | { .device = 0xbc }, |
157 | { } |
158 | }; |
159 | MODULE_DEVICE_TABLE(mcb, men_z188_ids); |
160 | |
161 | static struct mcb_driver men_z188_driver = { |
162 | .driver = { |
163 | .name = "z188-adc" , |
164 | }, |
165 | .probe = men_z188_probe, |
166 | .remove = men_z188_remove, |
167 | .id_table = men_z188_ids, |
168 | }; |
169 | module_mcb_driver(men_z188_driver); |
170 | |
171 | MODULE_AUTHOR("Johannes Thumshirn <johannes.thumshirn@men.de>" ); |
172 | MODULE_LICENSE("GPL" ); |
173 | MODULE_DESCRIPTION("IIO ADC driver for MEN 16z188 ADC Core" ); |
174 | MODULE_ALIAS("mcb:16z188" ); |
175 | MODULE_IMPORT_NS(MCB); |
176 | |