1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * AD7606 Parallel Interface ADC driver
4 *
5 * Copyright 2011 - 2024 Analog Devices Inc.
6 * Copyright 2024 BayLibre SAS.
7 */
8
9 #include <linux/err.h>
10 #include <linux/gpio/consumer.h>
11 #include <linux/io.h>
12 #include <linux/mod_devicetable.h>
13 #include <linux/module.h>
14 #include <linux/platform_device.h>
15 #include <linux/property.h>
16 #include <linux/types.h>
17
18 #include <linux/iio/backend.h>
19 #include <linux/iio/iio.h>
20
21 #include "ad7606.h"
22 #include "ad7606_bus_iface.h"
23
ad7606_par_bus_update_scan_mode(struct iio_dev * indio_dev,const unsigned long * scan_mask)24 static int ad7606_par_bus_update_scan_mode(struct iio_dev *indio_dev,
25 const unsigned long *scan_mask)
26 {
27 struct ad7606_state *st = iio_priv(indio_dev);
28 unsigned int c, ret;
29
30 for (c = 0; c < indio_dev->num_channels; c++) {
31 if (test_bit(c, scan_mask))
32 ret = iio_backend_chan_enable(st->back, c);
33 else
34 ret = iio_backend_chan_disable(st->back, c);
35 if (ret)
36 return ret;
37 }
38
39 return 0;
40 }
41
ad7606_par_bus_setup_iio_backend(struct device * dev,struct iio_dev * indio_dev)42 static int ad7606_par_bus_setup_iio_backend(struct device *dev,
43 struct iio_dev *indio_dev)
44 {
45 struct ad7606_state *st = iio_priv(indio_dev);
46 unsigned int ret, c;
47 struct iio_backend_data_fmt data = {
48 .sign_extend = true,
49 .enable = true,
50 };
51
52 st->back = devm_iio_backend_get(dev, NULL);
53 if (IS_ERR(st->back))
54 return PTR_ERR(st->back);
55
56 /* If the device is iio_backend powered the PWM is mandatory */
57 if (!st->cnvst_pwm)
58 return dev_err_probe(st->dev, -EINVAL,
59 "A PWM is mandatory when using backend.\n");
60
61 ret = devm_iio_backend_request_buffer(dev, st->back, indio_dev);
62 if (ret)
63 return ret;
64
65 ret = devm_iio_backend_enable(dev, st->back);
66 if (ret)
67 return ret;
68
69 for (c = 0; c < indio_dev->num_channels; c++) {
70 ret = iio_backend_data_format_set(st->back, c, &data);
71 if (ret)
72 return ret;
73 }
74
75 return 0;
76 }
77
ad7606_par_bus_reg_read(struct ad7606_state * st,unsigned int addr)78 static int ad7606_par_bus_reg_read(struct ad7606_state *st, unsigned int addr)
79 {
80 struct ad7606_platform_data *pdata = st->dev->platform_data;
81 int val, ret;
82
83 ret = pdata->bus_reg_read(st->back, addr, &val);
84 if (ret)
85 return ret;
86
87 return val;
88 }
89
ad7606_par_bus_reg_write(struct ad7606_state * st,unsigned int addr,unsigned int val)90 static int ad7606_par_bus_reg_write(struct ad7606_state *st, unsigned int addr,
91 unsigned int val)
92 {
93 struct ad7606_platform_data *pdata = st->dev->platform_data;
94
95 return pdata->bus_reg_write(st->back, addr, val);
96 }
97
98 static const struct ad7606_bus_ops ad7606_bi_bops = {
99 .iio_backend_config = ad7606_par_bus_setup_iio_backend,
100 .update_scan_mode = ad7606_par_bus_update_scan_mode,
101 .reg_read = ad7606_par_bus_reg_read,
102 .reg_write = ad7606_par_bus_reg_write,
103 };
104
ad7606_par16_read_block(struct device * dev,int count,void * buf)105 static int ad7606_par16_read_block(struct device *dev,
106 int count, void *buf)
107 {
108 struct iio_dev *indio_dev = dev_get_drvdata(dev);
109 struct ad7606_state *st = iio_priv(indio_dev);
110
111
112 /*
113 * On the parallel interface, the frstdata signal is set to high while
114 * and after reading the sample of the first channel and low for all
115 * other channels. This can be used to check that the incoming data is
116 * correctly aligned. During normal operation the data should never
117 * become unaligned, but some glitch or electrostatic discharge might
118 * cause an extra read or clock cycle. Monitoring the frstdata signal
119 * allows to recover from such failure situations.
120 */
121 int num = count;
122 u16 *_buf = buf;
123
124 if (st->gpio_frstdata) {
125 insw((unsigned long)st->base_address, _buf, 1);
126 if (!gpiod_get_value(st->gpio_frstdata)) {
127 ad7606_reset(st);
128 return -EIO;
129 }
130 _buf++;
131 num--;
132 }
133 insw((unsigned long)st->base_address, _buf, num);
134 return 0;
135 }
136
137 static const struct ad7606_bus_ops ad7606_par16_bops = {
138 .read_block = ad7606_par16_read_block,
139 };
140
ad7606_par8_read_block(struct device * dev,int count,void * buf)141 static int ad7606_par8_read_block(struct device *dev,
142 int count, void *buf)
143 {
144 struct iio_dev *indio_dev = dev_get_drvdata(dev);
145 struct ad7606_state *st = iio_priv(indio_dev);
146 /*
147 * On the parallel interface, the frstdata signal is set to high while
148 * and after reading the sample of the first channel and low for all
149 * other channels. This can be used to check that the incoming data is
150 * correctly aligned. During normal operation the data should never
151 * become unaligned, but some glitch or electrostatic discharge might
152 * cause an extra read or clock cycle. Monitoring the frstdata signal
153 * allows to recover from such failure situations.
154 */
155 int num = count;
156 u16 *_buf = buf;
157
158 if (st->gpio_frstdata) {
159 insb((unsigned long)st->base_address, _buf, 2);
160 if (!gpiod_get_value(st->gpio_frstdata)) {
161 ad7606_reset(st);
162 return -EIO;
163 }
164 _buf++;
165 num--;
166 }
167 insb((unsigned long)st->base_address, _buf, num * 2);
168
169 return 0;
170 }
171
172 static const struct ad7606_bus_ops ad7606_par8_bops = {
173 .read_block = ad7606_par8_read_block,
174 };
175
ad7606_par_probe(struct platform_device * pdev)176 static int ad7606_par_probe(struct platform_device *pdev)
177 {
178 const struct ad7606_chip_info *chip_info;
179 const struct platform_device_id *id;
180 struct resource *res;
181 void __iomem *addr;
182 resource_size_t remap_size;
183 int irq;
184
185 /*
186 * If a firmware node is available (ACPI or DT), platform_device_id is null
187 * and we must use get_match_data.
188 */
189 if (dev_fwnode(&pdev->dev)) {
190 chip_info = device_get_match_data(&pdev->dev);
191 if (device_property_present(&pdev->dev, "io-backends"))
192 /*
193 * If a backend is available ,call the core probe with backend
194 * bops, otherwise use the former bops.
195 */
196 return ad7606_probe(&pdev->dev, 0, NULL,
197 chip_info,
198 &ad7606_bi_bops);
199 } else {
200 id = platform_get_device_id(pdev);
201 chip_info = (const struct ad7606_chip_info *)id->driver_data;
202 }
203
204 irq = platform_get_irq(pdev, 0);
205 if (irq < 0)
206 return irq;
207
208 addr = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
209 if (IS_ERR(addr))
210 return PTR_ERR(addr);
211
212 remap_size = resource_size(res);
213
214 return ad7606_probe(&pdev->dev, irq, addr, chip_info,
215 remap_size > 1 ? &ad7606_par16_bops :
216 &ad7606_par8_bops);
217 }
218
219 static const struct platform_device_id ad7606_driver_ids[] = {
220 { .name = "ad7605-4", .driver_data = (kernel_ulong_t)&ad7605_4_info, },
221 { .name = "ad7606-4", .driver_data = (kernel_ulong_t)&ad7606_4_info, },
222 { .name = "ad7606-6", .driver_data = (kernel_ulong_t)&ad7606_6_info, },
223 { .name = "ad7606-8", .driver_data = (kernel_ulong_t)&ad7606_8_info, },
224 { .name = "ad7606b", .driver_data = (kernel_ulong_t)&ad7606b_info, },
225 { .name = "ad7606c-16", .driver_data = (kernel_ulong_t)&ad7606c_16_info },
226 { .name = "ad7606c-18", .driver_data = (kernel_ulong_t)&ad7606c_18_info },
227 { .name = "ad7607", .driver_data = (kernel_ulong_t)&ad7607_info, },
228 { .name = "ad7608", .driver_data = (kernel_ulong_t)&ad7608_info, },
229 { .name = "ad7609", .driver_data = (kernel_ulong_t)&ad7609_info, },
230 { }
231 };
232 MODULE_DEVICE_TABLE(platform, ad7606_driver_ids);
233
234 static const struct of_device_id ad7606_of_match[] = {
235 { .compatible = "adi,ad7605-4", .data = &ad7605_4_info },
236 { .compatible = "adi,ad7606-4", .data = &ad7606_4_info },
237 { .compatible = "adi,ad7606-6", .data = &ad7606_6_info },
238 { .compatible = "adi,ad7606-8", .data = &ad7606_8_info },
239 { .compatible = "adi,ad7606b", .data = &ad7606b_info },
240 { .compatible = "adi,ad7606c-16", .data = &ad7606c_16_info },
241 { .compatible = "adi,ad7606c-18", .data = &ad7606c_18_info },
242 { .compatible = "adi,ad7607", .data = &ad7607_info },
243 { .compatible = "adi,ad7608", .data = &ad7608_info },
244 { .compatible = "adi,ad7609", .data = &ad7609_info },
245 { }
246 };
247 MODULE_DEVICE_TABLE(of, ad7606_of_match);
248
249 static struct platform_driver ad7606_driver = {
250 .probe = ad7606_par_probe,
251 .id_table = ad7606_driver_ids,
252 .driver = {
253 .name = "ad7606",
254 .pm = AD7606_PM_OPS,
255 .of_match_table = ad7606_of_match,
256 },
257 };
258 module_platform_driver(ad7606_driver);
259
260 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
261 MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
262 MODULE_LICENSE("GPL v2");
263 MODULE_IMPORT_NS("IIO_AD7606");
264 MODULE_IMPORT_NS("IIO_BACKEND");
265