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 c;
47 int ret;
48 struct iio_backend_data_fmt data = {
49 .sign_extend = true,
50 .enable = true,
51 };
52
53 st->back = devm_iio_backend_get(dev, NULL);
54 if (IS_ERR(st->back))
55 return PTR_ERR(st->back);
56
57 /* If the device is iio_backend powered the PWM is mandatory */
58 if (!st->cnvst_pwm)
59 return dev_err_probe(st->dev, -EINVAL,
60 "A PWM is mandatory when using backend.\n");
61
62 ret = devm_iio_backend_request_buffer(dev, st->back, indio_dev);
63 if (ret)
64 return ret;
65
66 ret = devm_iio_backend_enable(dev, st->back);
67 if (ret)
68 return ret;
69
70 for (c = 0; c < indio_dev->num_channels; c++) {
71 ret = iio_backend_data_format_set(st->back, c, &data);
72 if (ret)
73 return ret;
74 }
75
76 return 0;
77 }
78
ad7606_par_bus_reg_read(struct ad7606_state * st,unsigned int addr)79 static int ad7606_par_bus_reg_read(struct ad7606_state *st, unsigned int addr)
80 {
81 struct ad7606_platform_data *pdata = st->dev->platform_data;
82 int val, ret;
83
84 ret = pdata->bus_reg_read(st->back, addr, &val);
85 if (ret)
86 return ret;
87
88 return val;
89 }
90
ad7606_par_bus_reg_write(struct ad7606_state * st,unsigned int addr,unsigned int val)91 static int ad7606_par_bus_reg_write(struct ad7606_state *st, unsigned int addr,
92 unsigned int val)
93 {
94 struct ad7606_platform_data *pdata = st->dev->platform_data;
95
96 return pdata->bus_reg_write(st->back, addr, val);
97 }
98
99 static const struct ad7606_bus_ops ad7606_bi_bops = {
100 .iio_backend_config = ad7606_par_bus_setup_iio_backend,
101 .update_scan_mode = ad7606_par_bus_update_scan_mode,
102 .reg_read = ad7606_par_bus_reg_read,
103 .reg_write = ad7606_par_bus_reg_write,
104 };
105
ad7606_par16_read_block(struct device * dev,int count,void * buf)106 static int ad7606_par16_read_block(struct device *dev,
107 int count, void *buf)
108 {
109 struct iio_dev *indio_dev = dev_get_drvdata(dev);
110 struct ad7606_state *st = iio_priv(indio_dev);
111
112
113 /*
114 * On the parallel interface, the frstdata signal is set to high while
115 * and after reading the sample of the first channel and low for all
116 * other channels. This can be used to check that the incoming data is
117 * correctly aligned. During normal operation the data should never
118 * become unaligned, but some glitch or electrostatic discharge might
119 * cause an extra read or clock cycle. Monitoring the frstdata signal
120 * allows to recover from such failure situations.
121 */
122 int num = count;
123 u16 *_buf = buf;
124
125 if (st->gpio_frstdata) {
126 insw((unsigned long)st->base_address, _buf, 1);
127 if (!gpiod_get_value(st->gpio_frstdata)) {
128 ad7606_reset(st);
129 return -EIO;
130 }
131 _buf++;
132 num--;
133 }
134 insw((unsigned long)st->base_address, _buf, num);
135 return 0;
136 }
137
138 static const struct ad7606_bus_ops ad7606_par16_bops = {
139 .read_block = ad7606_par16_read_block,
140 };
141
ad7606_par8_read_block(struct device * dev,int count,void * buf)142 static int ad7606_par8_read_block(struct device *dev,
143 int count, void *buf)
144 {
145 struct iio_dev *indio_dev = dev_get_drvdata(dev);
146 struct ad7606_state *st = iio_priv(indio_dev);
147 /*
148 * On the parallel interface, the frstdata signal is set to high while
149 * and after reading the sample of the first channel and low for all
150 * other channels. This can be used to check that the incoming data is
151 * correctly aligned. During normal operation the data should never
152 * become unaligned, but some glitch or electrostatic discharge might
153 * cause an extra read or clock cycle. Monitoring the frstdata signal
154 * allows to recover from such failure situations.
155 */
156 int num = count;
157 u16 *_buf = buf;
158
159 if (st->gpio_frstdata) {
160 insb((unsigned long)st->base_address, _buf, 2);
161 if (!gpiod_get_value(st->gpio_frstdata)) {
162 ad7606_reset(st);
163 return -EIO;
164 }
165 _buf++;
166 num--;
167 }
168 insb((unsigned long)st->base_address, _buf, num * 2);
169
170 return 0;
171 }
172
173 static const struct ad7606_bus_ops ad7606_par8_bops = {
174 .read_block = ad7606_par8_read_block,
175 };
176
ad7606_par_probe(struct platform_device * pdev)177 static int ad7606_par_probe(struct platform_device *pdev)
178 {
179 const struct ad7606_chip_info *chip_info;
180 const struct platform_device_id *id;
181 struct resource *res;
182 void __iomem *addr;
183 resource_size_t remap_size;
184 int irq;
185
186 /*
187 * If a firmware node is available (ACPI or DT), platform_device_id is null
188 * and we must use get_match_data.
189 */
190 if (dev_fwnode(&pdev->dev)) {
191 chip_info = device_get_match_data(&pdev->dev);
192 if (device_property_present(&pdev->dev, "io-backends"))
193 /*
194 * If a backend is available ,call the core probe with backend
195 * bops, otherwise use the former bops.
196 */
197 return ad7606_probe(&pdev->dev, 0, NULL,
198 chip_info,
199 &ad7606_bi_bops);
200 } else {
201 id = platform_get_device_id(pdev);
202 chip_info = (const struct ad7606_chip_info *)id->driver_data;
203 }
204
205 irq = platform_get_irq(pdev, 0);
206 if (irq < 0)
207 return irq;
208
209 addr = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
210 if (IS_ERR(addr))
211 return PTR_ERR(addr);
212
213 remap_size = resource_size(res);
214
215 return ad7606_probe(&pdev->dev, irq, addr, chip_info,
216 remap_size > 1 ? &ad7606_par16_bops :
217 &ad7606_par8_bops);
218 }
219
220 static const struct platform_device_id ad7606_driver_ids[] = {
221 { .name = "ad7605-4", .driver_data = (kernel_ulong_t)&ad7605_4_info, },
222 { .name = "ad7606-4", .driver_data = (kernel_ulong_t)&ad7606_4_info, },
223 { .name = "ad7606-6", .driver_data = (kernel_ulong_t)&ad7606_6_info, },
224 { .name = "ad7606-8", .driver_data = (kernel_ulong_t)&ad7606_8_info, },
225 { .name = "ad7606b", .driver_data = (kernel_ulong_t)&ad7606b_info, },
226 { .name = "ad7606c-16", .driver_data = (kernel_ulong_t)&ad7606c_16_info },
227 { .name = "ad7606c-18", .driver_data = (kernel_ulong_t)&ad7606c_18_info },
228 { .name = "ad7607", .driver_data = (kernel_ulong_t)&ad7607_info, },
229 { .name = "ad7608", .driver_data = (kernel_ulong_t)&ad7608_info, },
230 { .name = "ad7609", .driver_data = (kernel_ulong_t)&ad7609_info, },
231 { }
232 };
233 MODULE_DEVICE_TABLE(platform, ad7606_driver_ids);
234
235 static const struct of_device_id ad7606_of_match[] = {
236 { .compatible = "adi,ad7605-4", .data = &ad7605_4_info },
237 { .compatible = "adi,ad7606-4", .data = &ad7606_4_info },
238 { .compatible = "adi,ad7606-6", .data = &ad7606_6_info },
239 { .compatible = "adi,ad7606-8", .data = &ad7606_8_info },
240 { .compatible = "adi,ad7606b", .data = &ad7606b_info },
241 { .compatible = "adi,ad7606c-16", .data = &ad7606c_16_info },
242 { .compatible = "adi,ad7606c-18", .data = &ad7606c_18_info },
243 { .compatible = "adi,ad7607", .data = &ad7607_info },
244 { .compatible = "adi,ad7608", .data = &ad7608_info },
245 { .compatible = "adi,ad7609", .data = &ad7609_info },
246 { }
247 };
248 MODULE_DEVICE_TABLE(of, ad7606_of_match);
249
250 static struct platform_driver ad7606_driver = {
251 .probe = ad7606_par_probe,
252 .id_table = ad7606_driver_ids,
253 .driver = {
254 .name = "ad7606",
255 .pm = AD7606_PM_OPS,
256 .of_match_table = ad7606_of_match,
257 },
258 };
259 module_platform_driver(ad7606_driver);
260
261 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
262 MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
263 MODULE_LICENSE("GPL v2");
264 MODULE_IMPORT_NS("IIO_AD7606");
265 MODULE_IMPORT_NS("IIO_BACKEND");
266