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); 250