drivers/iio/adc/ad7606_par.c

   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
  23 static const struct iio_chan_spec ad7606b_bi_channels[] = {
  24         AD7606_BI_CHANNEL(0),
  25         AD7606_BI_CHANNEL(1),
  26         AD7606_BI_CHANNEL(2),
  27         AD7606_BI_CHANNEL(3),
  28         AD7606_BI_CHANNEL(4),
  29         AD7606_BI_CHANNEL(5),
  30         AD7606_BI_CHANNEL(6),
  31         AD7606_BI_CHANNEL(7),
  32 };
  33
  34 static int ad7606_bi_update_scan_mode(struct iio_dev *indio_dev, const unsigned long *scan_mask)
  35 {
  36         struct ad7606_state *st = iio_priv(indio_dev);
  37         unsigned int c, ret;
  38
  39         for (c = 0; c < indio_dev->num_channels; c++) {
  40                 if (test_bit(c, scan_mask))
  41                         ret = iio_backend_chan_enable(st->back, c);
  42                 else
  43                         ret = iio_backend_chan_disable(st->back, c);
  44                 if (ret)
  45                         return ret;
  46         }
  47
  48         return 0;
  49 }
  50
  51 static int ad7606_bi_setup_iio_backend(struct device *dev, struct iio_dev *indio_dev)
  52 {
  53         struct ad7606_state *st = iio_priv(indio_dev);
  54         unsigned int ret, c;
  55         struct iio_backend_data_fmt data = {
  56                 .sign_extend = true,
  57                 .enable = true,
  58         };
  59
  60         st->back = devm_iio_backend_get(dev, NULL);
  61         if (IS_ERR(st->back))
  62                 return PTR_ERR(st->back);
  63
  64         /* If the device is iio_backend powered the PWM is mandatory */
  65         if (!st->cnvst_pwm)
  66                 return dev_err_probe(st->dev, -EINVAL,
  67                                      "A PWM is mandatory when using backend.\n");
  68
  69         ret = devm_iio_backend_request_buffer(dev, st->back, indio_dev);
  70         if (ret)
  71                 return ret;
  72
  73         ret = devm_iio_backend_enable(dev, st->back);
  74         if (ret)
  75                 return ret;
  76
  77         for (c = 0; c < indio_dev->num_channels; c++) {
  78                 ret = iio_backend_data_format_set(st->back, c, &data);
  79                 if (ret)
  80                         return ret;
  81         }
  82
  83         indio_dev->channels = ad7606b_bi_channels;
  84         indio_dev->num_channels = 8;
  85
  86         return 0;
  87 }
  88
  89 static const struct ad7606_bus_ops ad7606_bi_bops = {
  90         .iio_backend_config = ad7606_bi_setup_iio_backend,
  91         .update_scan_mode = ad7606_bi_update_scan_mode,
  92 };
  93
  94 static int ad7606_par16_read_block(struct device *dev,
  95                                    int count, void *buf)
  96 {
  97         struct iio_dev *indio_dev = dev_get_drvdata(dev);
  98         struct ad7606_state *st = iio_priv(indio_dev);
  99
 100
 101         /*
 102          * On the parallel interface, the frstdata signal is set to high while
 103          * and after reading the sample of the first channel and low for all
 104          * other channels.  This can be used to check that the incoming data is
 105          * correctly aligned.  During normal operation the data should never
 106          * become unaligned, but some glitch or electrostatic discharge might
 107          * cause an extra read or clock cycle.  Monitoring the frstdata signal
 108          * allows to recover from such failure situations.
 109          */
 110         int num = count;
 111         u16 *_buf = buf;
 112
 113         if (st->gpio_frstdata) {
 114                 insw((unsigned long)st->base_address, _buf, 1);
 115                 if (!gpiod_get_value(st->gpio_frstdata)) {
 116                         ad7606_reset(st);
 117                         return -EIO;
 118                 }
 119                 _buf++;
 120                 num--;
 121         }
 122         insw((unsigned long)st->base_address, _buf, num);
 123         return 0;
 124 }
 125
 126 static const struct ad7606_bus_ops ad7606_par16_bops = {
 127         .read_block = ad7606_par16_read_block,
 128 };
 129
 130 static int ad7606_par8_read_block(struct device *dev,
 131                                   int count, void *buf)
 132 {
 133         struct iio_dev *indio_dev = dev_get_drvdata(dev);
 134         struct ad7606_state *st = iio_priv(indio_dev);
 135         /*
 136          * On the parallel interface, the frstdata signal is set to high while
 137          * and after reading the sample of the first channel and low for all
 138          * other channels.  This can be used to check that the incoming data is
 139          * correctly aligned.  During normal operation the data should never
 140          * become unaligned, but some glitch or electrostatic discharge might
 141          * cause an extra read or clock cycle.  Monitoring the frstdata signal
 142          * allows to recover from such failure situations.
 143          */
 144         int num = count;
 145         u16 *_buf = buf;
 146
 147         if (st->gpio_frstdata) {
 148                 insb((unsigned long)st->base_address, _buf, 2);
 149                 if (!gpiod_get_value(st->gpio_frstdata)) {
 150                         ad7606_reset(st);
 151                         return -EIO;
 152                 }
 153                 _buf++;
 154                 num--;
 155         }
 156         insb((unsigned long)st->base_address, _buf, num * 2);
 157
 158         return 0;
 159 }
 160
 161 static const struct ad7606_bus_ops ad7606_par8_bops = {
 162         .read_block = ad7606_par8_read_block,
 163 };
 164
 165 static int ad7606_par_probe(struct platform_device *pdev)
 166 {
 167         const struct ad7606_chip_info *chip_info;
 168         const struct platform_device_id *id;
 169         struct resource *res;
 170         void __iomem *addr;
 171         resource_size_t remap_size;
 172         int irq;
 173
 174         /*
 175          * If a firmware node is available (ACPI or DT), platform_device_id is null
 176          * and we must use get_match_data.
 177          */
 178         if (dev_fwnode(&pdev->dev)) {
 179                 chip_info = device_get_match_data(&pdev->dev);
 180                 if (device_property_present(&pdev->dev, "io-backends"))
 181                         /*
 182                          * If a backend is available ,call the core probe with backend
 183                          * bops, otherwise use the former bops.
 184                          */
 185                         return ad7606_probe(&pdev->dev, 0, NULL,
 186                                             chip_info,
 187                                             &ad7606_bi_bops);
 188         } else {
 189                 id = platform_get_device_id(pdev);
 190                 chip_info = (const struct ad7606_chip_info *)id->driver_data;
 191         }
 192
 193         irq = platform_get_irq(pdev, 0);
 194         if (irq < 0)
 195                 return irq;
 196
 197         addr = devm_platform_get_and_ioremap_resource(pdev, 0, &res);
 198         if (IS_ERR(addr))
 199                 return PTR_ERR(addr);
 200
 201         remap_size = resource_size(res);
 202
 203         return ad7606_probe(&pdev->dev, irq, addr, chip_info,
 204                             remap_size > 1 ? &ad7606_par16_bops :
 205                             &ad7606_par8_bops);
 206 }
 207
 208 static const struct platform_device_id ad7606_driver_ids[] = {
 209         { .name = "ad7605-4", .driver_data = (kernel_ulong_t)&ad7605_4_info, },
 210         { .name = "ad7606-4", .driver_data = (kernel_ulong_t)&ad7606_4_info, },
 211         { .name = "ad7606-6", .driver_data = (kernel_ulong_t)&ad7606_6_info, },
 212         { .name = "ad7606-8", .driver_data = (kernel_ulong_t)&ad7606_8_info, },
 213         { .name = "ad7606b", .driver_data = (kernel_ulong_t)&ad7606b_info, },
 214         { .name = "ad7607", .driver_data = (kernel_ulong_t)&ad7607_info, },
 215         { .name = "ad7608", .driver_data = (kernel_ulong_t)&ad7608_info, },
 216         { .name = "ad7609", .driver_data = (kernel_ulong_t)&ad7609_info, },
 217         { }
 218 };
 219 MODULE_DEVICE_TABLE(platform, ad7606_driver_ids);
 220
 221 static const struct of_device_id ad7606_of_match[] = {
 222         { .compatible = "adi,ad7605-4", .data = &ad7605_4_info },
 223         { .compatible = "adi,ad7606-4", .data = &ad7606_4_info },
 224         { .compatible = "adi,ad7606-6", .data = &ad7606_6_info },
 225         { .compatible = "adi,ad7606-8", .data = &ad7606_8_info },
 226         { .compatible = "adi,ad7606b", .data = &ad7606b_info },
 227         { .compatible = "adi,ad7607", .data = &ad7607_info },
 228         { .compatible = "adi,ad7608", .data = &ad7608_info },
 229         { .compatible = "adi,ad7609", .data = &ad7609_info },
 230         { }
 231 };
 232 MODULE_DEVICE_TABLE(of, ad7606_of_match);
 233
 234 static struct platform_driver ad7606_driver = {
 235         .probe = ad7606_par_probe,
 236         .id_table = ad7606_driver_ids,
 237         .driver = {
 238                 .name = "ad7606",
 239                 .pm = AD7606_PM_OPS,
 240                 .of_match_table = ad7606_of_match,
 241         },
 242 };
 243 module_platform_driver(ad7606_driver);
 244
 245 MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>");
 246 MODULE_DESCRIPTION("Analog Devices AD7606 ADC");
 247 MODULE_LICENSE("GPL v2");
 248 MODULE_IMPORT_NS("IIO_AD7606");
 249 MODULE_IMPORT_NS("IIO_BACKEND");