1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * AD7606 Parallel Interface ADC driver
4 *
5 * Copyright 2011 Analog Devices Inc.
6 */
7
8 #include <linux/mod_devicetable.h>
9 #include <linux/module.h>
10 #include <linux/gpio/consumer.h>
11 #include <linux/platform_device.h>
12 #include <linux/types.h>
13 #include <linux/err.h>
14 #include <linux/io.h>
15
16 #include <linux/iio/iio.h>
17 #include "ad7606.h"
18
ad7606_par16_read_block(struct device * dev,int count,void * buf)19 static int ad7606_par16_read_block(struct device *dev,
20 int count, void *buf)
21 {
22 struct iio_dev *indio_dev = dev_get_drvdata(dev);
23 struct ad7606_state *st = iio_priv(indio_dev);
24
25
26 /*
27 * On the parallel interface, the frstdata signal is set to high while
28 * and after reading the sample of the first channel and low for all
29 * other channels. This can be used to check that the incoming data is
30 * correctly aligned. During normal operation the data should never
31 * become unaligned, but some glitch or electrostatic discharge might
32 * cause an extra read or clock cycle. Monitoring the frstdata signal
33 * allows to recover from such failure situations.
34 */
35 int num = count;
36 u16 *_buf = buf;
37
38 if (st->gpio_frstdata) {
39 insw((unsigned long)st->base_address, _buf, 1);
40 if (!gpiod_get_value(st->gpio_frstdata)) {
41 ad7606_reset(st);
42 return -EIO;
43 }
44 _buf++;
45 num--;
46 }
47 insw((unsigned long)st->base_address, _buf, num);
48 return 0;
49 }
50
51 static const struct ad7606_bus_ops ad7606_par16_bops = {
52 .read_block = ad7606_par16_read_block,
53 };
54
ad7606_par8_read_block(struct device * dev,int count,void * buf)55 static int ad7606_par8_read_block(struct device *dev,
56 int count, void *buf)
57 {
58 struct iio_dev *indio_dev = dev_get_drvdata(dev);
59 struct ad7606_state *st = iio_priv(indio_dev);
60 /*
61 * On the parallel interface, the frstdata signal is set to high while
62 * and after reading the sample of the first channel and low for all
63 * other channels. This can be used to check that the incoming data is
64 * correctly aligned. During normal operation the data should never
65 * become unaligned, but some glitch or electrostatic discharge might
66 * cause an extra read or clock cycle. Monitoring the frstdata signal
67 * allows to recover from such failure situations.
68 */
69 int num = count;
70 u16 *_buf = buf;
71
72 if (st->gpio_frstdata) {
73 insb((unsigned long)st->base_address, _buf, 2);
74 if (!gpiod_get_value(st->gpio_frstdata)) {
75 ad7606_reset(st);
76 return -EIO;
77 }
78 _buf++;
79 num--;
80 }
81 insb((unsigned long)st->base_address, _buf, num * 2);
82
83 return 0;
84 }
85
86 static const struct ad7606_bus_ops ad7606_par8_bops = {
87 .read_block = ad7606_par8_read_block,
88 };
89
ad7606_par_probe(struct platform_device * pdev)90 static int ad7606_par_probe(struct platform_device *pdev)
91 {
92 const struct platform_device_id *id = platform_get_device_id(pdev);
93 struct resource *res;
94 void __iomem *addr;
95 resource_size_t remap_size;
96 int irq;
97
98 irq = platform_get_irq(pdev, 0);
99 if (irq < 0)
100 return irq;
101
102 addr = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
103 if (IS_ERR(addr))
104 return PTR_ERR(addr);
105
106 remap_size = resource_size(res);
107
108 return ad7606_probe(&pdev->dev, irq, addr,
109 id->name, id->driver_data,
110 remap_size > 1 ? &ad7606_par16_bops :
111 &ad7606_par8_bops);
112 }
113
114 static const struct platform_device_id ad7606_driver_ids[] = {
115 { .name = "ad7605-4", .driver_data = ID_AD7605_4, },
116 { .name = "ad7606-4", .driver_data = ID_AD7606_4, },
117 { .name = "ad7606-6", .driver_data = ID_AD7606_6, },
118 { .name = "ad7606-8", .driver_data = ID_AD7606_8, },
119 { }
120 };
121 MODULE_DEVICE_TABLE(platform, ad7606_driver_ids);
122
123 static const struct of_device_id ad7606_of_match[] = {
124 { .compatible = "adi,ad7605-4" },
125 { .compatible = "adi,ad7606-4" },
126 { .compatible = "adi,ad7606-6" },
127 { .compatible = "adi,ad7606-8" },
128 { }
129 };
130 MODULE_DEVICE_TABLE(of, ad7606_of_match);
131
132 static struct platform_driver ad7606_driver = {
133 .probe = ad7606_par_probe,
134 .id_table = ad7606_driver_ids,
135 .driver = {
136 .name = "ad7606",
137 .pm = AD7606_PM_OPS,
138 .of_match_table = ad7606_of_match,
139 },
140 };
141 module_platform_driver(ad7606_driver);
142
143 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
144 MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
145 MODULE_LICENSE("GPL v2");
146 MODULE_IMPORT_NS(IIO_AD7606);
147