1 /* 2 * AD7466/7/8 AD7476/5/7/8 (A) SPI ADC driver 3 * 4 * Copyright 2010 Analog Devices Inc. 5 * 6 * Licensed under the GPL-2 or later. 7 */ 8 9 #include <linux/device.h> 10 #include <linux/kernel.h> 11 #include <linux/slab.h> 12 #include <linux/sysfs.h> 13 #include <linux/spi/spi.h> 14 #include <linux/regulator/consumer.h> 15 #include <linux/err.h> 16 #include <linux/module.h> 17 #include <linux/bitops.h> 18 19 #include <linux/iio/iio.h> 20 #include <linux/iio/sysfs.h> 21 #include <linux/iio/buffer.h> 22 #include <linux/iio/trigger_consumer.h> 23 #include <linux/iio/triggered_buffer.h> 24 25 struct ad7476_state; 26 27 struct ad7476_chip_info { 28 unsigned int int_vref_uv; 29 struct iio_chan_spec channel[2]; 30 void (*reset)(struct ad7476_state *); 31 }; 32 33 struct ad7476_state { 34 struct spi_device *spi; 35 const struct ad7476_chip_info *chip_info; 36 struct regulator *reg; 37 struct spi_transfer xfer; 38 struct spi_message msg; 39 /* 40 * DMA (thus cache coherency maintenance) requires the 41 * transfer buffers to live in their own cache lines. 42 * Make the buffer large enough for one 16 bit sample and one 64 bit 43 * aligned 64 bit timestamp. 44 */ 45 unsigned char data[ALIGN(2, sizeof(s64)) + sizeof(s64)] 46 ____cacheline_aligned; 47 }; 48 49 enum ad7476_supported_device_ids { 50 ID_AD7091R, 51 ID_AD7276, 52 ID_AD7277, 53 ID_AD7278, 54 ID_AD7466, 55 ID_AD7467, 56 ID_AD7468, 57 ID_AD7495, 58 ID_AD7940, 59 }; 60 61 static irqreturn_t ad7476_trigger_handler(int irq, void *p) 62 { 63 struct iio_poll_func *pf = p; 64 struct iio_dev *indio_dev = pf->indio_dev; 65 struct ad7476_state *st = iio_priv(indio_dev); 66 int b_sent; 67 68 b_sent = spi_sync(st->spi, &st->msg); 69 if (b_sent < 0) 70 goto done; 71 72 iio_push_to_buffers_with_timestamp(indio_dev, st->data, 73 iio_get_time_ns(indio_dev)); 74 done: 75 iio_trigger_notify_done(indio_dev->trig); 76 77 return IRQ_HANDLED; 78 } 79 80 static void ad7091_reset(struct ad7476_state *st) 81 { 82 /* Any transfers with 8 scl cycles will reset the device */ 83 spi_read(st->spi, st->data, 1); 84 } 85 86 static int ad7476_scan_direct(struct ad7476_state *st) 87 { 88 int ret; 89 90 ret = spi_sync(st->spi, &st->msg); 91 if (ret) 92 return ret; 93 94 return be16_to_cpup((__be16 *)st->data); 95 } 96 97 static int ad7476_read_raw(struct iio_dev *indio_dev, 98 struct iio_chan_spec const *chan, 99 int *val, 100 int *val2, 101 long m) 102 { 103 int ret; 104 struct ad7476_state *st = iio_priv(indio_dev); 105 int scale_uv; 106 107 switch (m) { 108 case IIO_CHAN_INFO_RAW: 109 ret = iio_device_claim_direct_mode(indio_dev); 110 if (ret) 111 return ret; 112 ret = ad7476_scan_direct(st); 113 iio_device_release_direct_mode(indio_dev); 114 115 if (ret < 0) 116 return ret; 117 *val = (ret >> st->chip_info->channel[0].scan_type.shift) & 118 GENMASK(st->chip_info->channel[0].scan_type.realbits - 1, 0); 119 return IIO_VAL_INT; 120 case IIO_CHAN_INFO_SCALE: 121 if (!st->chip_info->int_vref_uv) { 122 scale_uv = regulator_get_voltage(st->reg); 123 if (scale_uv < 0) 124 return scale_uv; 125 } else { 126 scale_uv = st->chip_info->int_vref_uv; 127 } 128 *val = scale_uv / 1000; 129 *val2 = chan->scan_type.realbits; 130 return IIO_VAL_FRACTIONAL_LOG2; 131 } 132 return -EINVAL; 133 } 134 135 #define _AD7476_CHAN(bits, _shift, _info_mask_sep) \ 136 { \ 137 .type = IIO_VOLTAGE, \ 138 .indexed = 1, \ 139 .info_mask_separate = _info_mask_sep, \ 140 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 141 .scan_type = { \ 142 .sign = 'u', \ 143 .realbits = (bits), \ 144 .storagebits = 16, \ 145 .shift = (_shift), \ 146 .endianness = IIO_BE, \ 147 }, \ 148 } 149 150 #define AD7476_CHAN(bits) _AD7476_CHAN((bits), 13 - (bits), \ 151 BIT(IIO_CHAN_INFO_RAW)) 152 #define AD7940_CHAN(bits) _AD7476_CHAN((bits), 15 - (bits), \ 153 BIT(IIO_CHAN_INFO_RAW)) 154 #define AD7091R_CHAN(bits) _AD7476_CHAN((bits), 16 - (bits), 0) 155 156 static const struct ad7476_chip_info ad7476_chip_info_tbl[] = { 157 [ID_AD7091R] = { 158 .channel[0] = AD7091R_CHAN(12), 159 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 160 .reset = ad7091_reset, 161 }, 162 [ID_AD7276] = { 163 .channel[0] = AD7940_CHAN(12), 164 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 165 }, 166 [ID_AD7277] = { 167 .channel[0] = AD7940_CHAN(10), 168 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 169 }, 170 [ID_AD7278] = { 171 .channel[0] = AD7940_CHAN(8), 172 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 173 }, 174 [ID_AD7466] = { 175 .channel[0] = AD7476_CHAN(12), 176 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 177 }, 178 [ID_AD7467] = { 179 .channel[0] = AD7476_CHAN(10), 180 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 181 }, 182 [ID_AD7468] = { 183 .channel[0] = AD7476_CHAN(8), 184 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 185 }, 186 [ID_AD7495] = { 187 .channel[0] = AD7476_CHAN(12), 188 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 189 .int_vref_uv = 2500000, 190 }, 191 [ID_AD7940] = { 192 .channel[0] = AD7940_CHAN(14), 193 .channel[1] = IIO_CHAN_SOFT_TIMESTAMP(1), 194 }, 195 }; 196 197 static const struct iio_info ad7476_info = { 198 .read_raw = &ad7476_read_raw, 199 }; 200 201 static int ad7476_probe(struct spi_device *spi) 202 { 203 struct ad7476_state *st; 204 struct iio_dev *indio_dev; 205 int ret; 206 207 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 208 if (!indio_dev) 209 return -ENOMEM; 210 211 st = iio_priv(indio_dev); 212 st->chip_info = 213 &ad7476_chip_info_tbl[spi_get_device_id(spi)->driver_data]; 214 215 st->reg = devm_regulator_get(&spi->dev, "vcc"); 216 if (IS_ERR(st->reg)) 217 return PTR_ERR(st->reg); 218 219 ret = regulator_enable(st->reg); 220 if (ret) 221 return ret; 222 223 spi_set_drvdata(spi, indio_dev); 224 225 st->spi = spi; 226 227 /* Establish that the iio_dev is a child of the spi device */ 228 indio_dev->dev.parent = &spi->dev; 229 indio_dev->dev.of_node = spi->dev.of_node; 230 indio_dev->name = spi_get_device_id(spi)->name; 231 indio_dev->modes = INDIO_DIRECT_MODE; 232 indio_dev->channels = st->chip_info->channel; 233 indio_dev->num_channels = 2; 234 indio_dev->info = &ad7476_info; 235 /* Setup default message */ 236 237 st->xfer.rx_buf = &st->data; 238 st->xfer.len = st->chip_info->channel[0].scan_type.storagebits / 8; 239 240 spi_message_init(&st->msg); 241 spi_message_add_tail(&st->xfer, &st->msg); 242 243 ret = iio_triggered_buffer_setup(indio_dev, NULL, 244 &ad7476_trigger_handler, NULL); 245 if (ret) 246 goto error_disable_reg; 247 248 if (st->chip_info->reset) 249 st->chip_info->reset(st); 250 251 ret = iio_device_register(indio_dev); 252 if (ret) 253 goto error_ring_unregister; 254 return 0; 255 256 error_ring_unregister: 257 iio_triggered_buffer_cleanup(indio_dev); 258 error_disable_reg: 259 regulator_disable(st->reg); 260 261 return ret; 262 } 263 264 static int ad7476_remove(struct spi_device *spi) 265 { 266 struct iio_dev *indio_dev = spi_get_drvdata(spi); 267 struct ad7476_state *st = iio_priv(indio_dev); 268 269 iio_device_unregister(indio_dev); 270 iio_triggered_buffer_cleanup(indio_dev); 271 regulator_disable(st->reg); 272 273 return 0; 274 } 275 276 static const struct spi_device_id ad7476_id[] = { 277 {"ad7091r", ID_AD7091R}, 278 {"ad7273", ID_AD7277}, 279 {"ad7274", ID_AD7276}, 280 {"ad7276", ID_AD7276}, 281 {"ad7277", ID_AD7277}, 282 {"ad7278", ID_AD7278}, 283 {"ad7466", ID_AD7466}, 284 {"ad7467", ID_AD7467}, 285 {"ad7468", ID_AD7468}, 286 {"ad7475", ID_AD7466}, 287 {"ad7476", ID_AD7466}, 288 {"ad7476a", ID_AD7466}, 289 {"ad7477", ID_AD7467}, 290 {"ad7477a", ID_AD7467}, 291 {"ad7478", ID_AD7468}, 292 {"ad7478a", ID_AD7468}, 293 {"ad7495", ID_AD7495}, 294 {"ad7910", ID_AD7467}, 295 {"ad7920", ID_AD7466}, 296 {"ad7940", ID_AD7940}, 297 {} 298 }; 299 MODULE_DEVICE_TABLE(spi, ad7476_id); 300 301 static struct spi_driver ad7476_driver = { 302 .driver = { 303 .name = "ad7476", 304 }, 305 .probe = ad7476_probe, 306 .remove = ad7476_remove, 307 .id_table = ad7476_id, 308 }; 309 module_spi_driver(ad7476_driver); 310 311 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 312 MODULE_DESCRIPTION("Analog Devices AD7476 and similar 1-channel ADCs"); 313 MODULE_LICENSE("GPL v2"); 314