Thomas Gleixner | 80503b2 | 2019-05-24 12:04:09 +0200 | [diff] [blame] | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 2 | /* |
| 3 | * AD7766/AD7767 SPI ADC driver |
| 4 | * |
| 5 | * Copyright 2016 Analog Devices Inc. |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 6 | */ |
| 7 | |
| 8 | #include <linux/clk.h> |
| 9 | #include <linux/delay.h> |
| 10 | #include <linux/device.h> |
| 11 | #include <linux/err.h> |
| 12 | #include <linux/gpio/consumer.h> |
| 13 | #include <linux/module.h> |
| 14 | #include <linux/regulator/consumer.h> |
| 15 | #include <linux/slab.h> |
| 16 | #include <linux/spi/spi.h> |
| 17 | |
| 18 | #include <linux/iio/iio.h> |
| 19 | #include <linux/iio/buffer.h> |
| 20 | #include <linux/iio/trigger.h> |
| 21 | #include <linux/iio/trigger_consumer.h> |
| 22 | #include <linux/iio/triggered_buffer.h> |
| 23 | |
| 24 | struct ad7766_chip_info { |
| 25 | unsigned int decimation_factor; |
| 26 | }; |
| 27 | |
| 28 | enum { |
| 29 | AD7766_SUPPLY_AVDD = 0, |
| 30 | AD7766_SUPPLY_DVDD = 1, |
| 31 | AD7766_SUPPLY_VREF = 2, |
| 32 | AD7766_NUM_SUPPLIES = 3 |
| 33 | }; |
| 34 | |
| 35 | struct ad7766 { |
| 36 | const struct ad7766_chip_info *chip_info; |
| 37 | struct spi_device *spi; |
| 38 | struct clk *mclk; |
| 39 | struct gpio_desc *pd_gpio; |
| 40 | struct regulator_bulk_data reg[AD7766_NUM_SUPPLIES]; |
| 41 | |
| 42 | struct iio_trigger *trig; |
| 43 | |
| 44 | struct spi_transfer xfer; |
| 45 | struct spi_message msg; |
| 46 | |
| 47 | /* |
| 48 | * DMA (thus cache coherency maintenance) requires the |
| 49 | * transfer buffers to live in their own cache lines. |
| 50 | * Make the buffer large enough for one 24 bit sample and one 64 bit |
| 51 | * aligned 64 bit timestamp. |
| 52 | */ |
| 53 | unsigned char data[ALIGN(3, sizeof(s64)) + sizeof(s64)] |
| 54 | ____cacheline_aligned; |
| 55 | }; |
| 56 | |
| 57 | /* |
| 58 | * AD7766 and AD7767 variations are interface compatible, the main difference is |
| 59 | * analog performance. Both parts will use the same ID. |
| 60 | */ |
| 61 | enum ad7766_device_ids { |
| 62 | ID_AD7766, |
| 63 | ID_AD7766_1, |
| 64 | ID_AD7766_2, |
| 65 | }; |
| 66 | |
| 67 | static irqreturn_t ad7766_trigger_handler(int irq, void *p) |
| 68 | { |
| 69 | struct iio_poll_func *pf = p; |
| 70 | struct iio_dev *indio_dev = pf->indio_dev; |
| 71 | struct ad7766 *ad7766 = iio_priv(indio_dev); |
| 72 | int ret; |
| 73 | |
| 74 | ret = spi_sync(ad7766->spi, &ad7766->msg); |
| 75 | if (ret < 0) |
| 76 | goto done; |
| 77 | |
| 78 | iio_push_to_buffers_with_timestamp(indio_dev, ad7766->data, |
| 79 | pf->timestamp); |
| 80 | done: |
| 81 | iio_trigger_notify_done(indio_dev->trig); |
| 82 | |
| 83 | return IRQ_HANDLED; |
| 84 | } |
| 85 | |
| 86 | static int ad7766_preenable(struct iio_dev *indio_dev) |
| 87 | { |
| 88 | struct ad7766 *ad7766 = iio_priv(indio_dev); |
| 89 | int ret; |
| 90 | |
| 91 | ret = regulator_bulk_enable(ARRAY_SIZE(ad7766->reg), ad7766->reg); |
| 92 | if (ret < 0) { |
| 93 | dev_err(&ad7766->spi->dev, "Failed to enable supplies: %d\n", |
| 94 | ret); |
| 95 | return ret; |
| 96 | } |
| 97 | |
| 98 | ret = clk_prepare_enable(ad7766->mclk); |
| 99 | if (ret < 0) { |
| 100 | dev_err(&ad7766->spi->dev, "Failed to enable MCLK: %d\n", ret); |
| 101 | regulator_bulk_disable(ARRAY_SIZE(ad7766->reg), ad7766->reg); |
| 102 | return ret; |
| 103 | } |
| 104 | |
Fabio Estevam | 8b298fb | 2017-07-16 18:26:03 -0300 | [diff] [blame] | 105 | gpiod_set_value(ad7766->pd_gpio, 0); |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 106 | |
| 107 | return 0; |
| 108 | } |
| 109 | |
| 110 | static int ad7766_postdisable(struct iio_dev *indio_dev) |
| 111 | { |
| 112 | struct ad7766 *ad7766 = iio_priv(indio_dev); |
| 113 | |
Fabio Estevam | 8b298fb | 2017-07-16 18:26:03 -0300 | [diff] [blame] | 114 | gpiod_set_value(ad7766->pd_gpio, 1); |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 115 | |
| 116 | /* |
| 117 | * The PD pin is synchronous to the clock, so give it some time to |
| 118 | * notice the change before we disable the clock. |
| 119 | */ |
| 120 | msleep(20); |
| 121 | |
| 122 | clk_disable_unprepare(ad7766->mclk); |
| 123 | regulator_bulk_disable(ARRAY_SIZE(ad7766->reg), ad7766->reg); |
| 124 | |
| 125 | return 0; |
| 126 | } |
| 127 | |
| 128 | static int ad7766_read_raw(struct iio_dev *indio_dev, |
| 129 | const struct iio_chan_spec *chan, int *val, int *val2, long info) |
| 130 | { |
| 131 | struct ad7766 *ad7766 = iio_priv(indio_dev); |
| 132 | struct regulator *vref = ad7766->reg[AD7766_SUPPLY_VREF].consumer; |
| 133 | int scale_uv; |
| 134 | |
| 135 | switch (info) { |
| 136 | case IIO_CHAN_INFO_SCALE: |
| 137 | scale_uv = regulator_get_voltage(vref); |
| 138 | if (scale_uv < 0) |
| 139 | return scale_uv; |
| 140 | *val = scale_uv / 1000; |
| 141 | *val2 = chan->scan_type.realbits; |
| 142 | return IIO_VAL_FRACTIONAL_LOG2; |
| 143 | case IIO_CHAN_INFO_SAMP_FREQ: |
| 144 | *val = clk_get_rate(ad7766->mclk) / |
| 145 | ad7766->chip_info->decimation_factor; |
| 146 | return IIO_VAL_INT; |
| 147 | } |
| 148 | return -EINVAL; |
| 149 | } |
| 150 | |
| 151 | static const struct iio_chan_spec ad7766_channels[] = { |
| 152 | { |
| 153 | .type = IIO_VOLTAGE, |
| 154 | .indexed = 1, |
| 155 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), |
| 156 | .info_mask_shared_by_all = BIT(IIO_CHAN_INFO_SAMP_FREQ), |
| 157 | .scan_type = { |
| 158 | .sign = 's', |
| 159 | .realbits = 24, |
| 160 | .storagebits = 32, |
| 161 | .endianness = IIO_BE, |
| 162 | }, |
| 163 | }, |
| 164 | IIO_CHAN_SOFT_TIMESTAMP(1), |
| 165 | }; |
| 166 | |
| 167 | static const struct ad7766_chip_info ad7766_chip_info[] = { |
| 168 | [ID_AD7766] = { |
| 169 | .decimation_factor = 8, |
| 170 | }, |
| 171 | [ID_AD7766_1] = { |
| 172 | .decimation_factor = 16, |
| 173 | }, |
| 174 | [ID_AD7766_2] = { |
| 175 | .decimation_factor = 32, |
| 176 | }, |
| 177 | }; |
| 178 | |
| 179 | static const struct iio_buffer_setup_ops ad7766_buffer_setup_ops = { |
| 180 | .preenable = &ad7766_preenable, |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 181 | .postdisable = &ad7766_postdisable, |
| 182 | }; |
| 183 | |
| 184 | static const struct iio_info ad7766_info = { |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 185 | .read_raw = &ad7766_read_raw, |
| 186 | }; |
| 187 | |
| 188 | static irqreturn_t ad7766_irq(int irq, void *private) |
| 189 | { |
| 190 | iio_trigger_poll(private); |
| 191 | return IRQ_HANDLED; |
| 192 | } |
| 193 | |
| 194 | static int ad7766_set_trigger_state(struct iio_trigger *trig, bool enable) |
| 195 | { |
| 196 | struct ad7766 *ad7766 = iio_trigger_get_drvdata(trig); |
| 197 | |
| 198 | if (enable) |
| 199 | enable_irq(ad7766->spi->irq); |
| 200 | else |
| 201 | disable_irq(ad7766->spi->irq); |
| 202 | |
| 203 | return 0; |
| 204 | } |
| 205 | |
| 206 | static const struct iio_trigger_ops ad7766_trigger_ops = { |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 207 | .set_trigger_state = ad7766_set_trigger_state, |
| 208 | .validate_device = iio_trigger_validate_own_device, |
| 209 | }; |
| 210 | |
| 211 | static int ad7766_probe(struct spi_device *spi) |
| 212 | { |
| 213 | const struct spi_device_id *id = spi_get_device_id(spi); |
| 214 | struct iio_dev *indio_dev; |
| 215 | struct ad7766 *ad7766; |
| 216 | int ret; |
| 217 | |
| 218 | indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*ad7766)); |
| 219 | if (!indio_dev) |
| 220 | return -ENOMEM; |
| 221 | |
| 222 | ad7766 = iio_priv(indio_dev); |
| 223 | ad7766->chip_info = &ad7766_chip_info[id->driver_data]; |
| 224 | |
| 225 | ad7766->mclk = devm_clk_get(&spi->dev, "mclk"); |
| 226 | if (IS_ERR(ad7766->mclk)) |
| 227 | return PTR_ERR(ad7766->mclk); |
| 228 | |
| 229 | ad7766->reg[AD7766_SUPPLY_AVDD].supply = "avdd"; |
| 230 | ad7766->reg[AD7766_SUPPLY_DVDD].supply = "dvdd"; |
| 231 | ad7766->reg[AD7766_SUPPLY_VREF].supply = "vref"; |
| 232 | |
| 233 | ret = devm_regulator_bulk_get(&spi->dev, ARRAY_SIZE(ad7766->reg), |
| 234 | ad7766->reg); |
Dan Carpenter | 0d8391f | 2016-11-10 22:30:18 +0300 | [diff] [blame] | 235 | if (ret) |
| 236 | return ret; |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 237 | |
| 238 | ad7766->pd_gpio = devm_gpiod_get_optional(&spi->dev, "powerdown", |
| 239 | GPIOD_OUT_HIGH); |
| 240 | if (IS_ERR(ad7766->pd_gpio)) |
| 241 | return PTR_ERR(ad7766->pd_gpio); |
| 242 | |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 243 | indio_dev->name = spi_get_device_id(spi)->name; |
| 244 | indio_dev->modes = INDIO_DIRECT_MODE; |
| 245 | indio_dev->channels = ad7766_channels; |
| 246 | indio_dev->num_channels = ARRAY_SIZE(ad7766_channels); |
| 247 | indio_dev->info = &ad7766_info; |
| 248 | |
| 249 | if (spi->irq > 0) { |
| 250 | ad7766->trig = devm_iio_trigger_alloc(&spi->dev, "%s-dev%d", |
Jonathan Cameron | 15ea2878 | 2021-04-26 18:49:03 +0100 | [diff] [blame] | 251 | indio_dev->name, |
| 252 | iio_device_id(indio_dev)); |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 253 | if (!ad7766->trig) |
| 254 | return -ENOMEM; |
| 255 | |
| 256 | ad7766->trig->ops = &ad7766_trigger_ops; |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 257 | iio_trigger_set_drvdata(ad7766->trig, ad7766); |
| 258 | |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 259 | /* |
| 260 | * The device generates interrupts as long as it is powered up. |
| 261 | * Some platforms might not allow the option to power it down so |
Jonathan Cameron | 0be49bd | 2021-04-02 19:45:38 +0100 | [diff] [blame] | 262 | * don't enable the interrupt to avoid extra load on the system |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 263 | */ |
Jonathan Cameron | 0be49bd | 2021-04-02 19:45:38 +0100 | [diff] [blame] | 264 | ret = devm_request_irq(&spi->dev, spi->irq, ad7766_irq, |
| 265 | IRQF_TRIGGER_FALLING | IRQF_NO_AUTOEN, |
| 266 | dev_name(&spi->dev), |
| 267 | ad7766->trig); |
| 268 | if (ret < 0) |
| 269 | return ret; |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 270 | |
| 271 | ret = devm_iio_trigger_register(&spi->dev, ad7766->trig); |
| 272 | if (ret) |
| 273 | return ret; |
| 274 | } |
| 275 | |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 276 | ad7766->spi = spi; |
| 277 | |
| 278 | /* First byte always 0 */ |
| 279 | ad7766->xfer.rx_buf = &ad7766->data[1]; |
| 280 | ad7766->xfer.len = 3; |
| 281 | |
| 282 | spi_message_init(&ad7766->msg); |
| 283 | spi_message_add_tail(&ad7766->xfer, &ad7766->msg); |
| 284 | |
| 285 | ret = devm_iio_triggered_buffer_setup(&spi->dev, indio_dev, |
| 286 | &iio_pollfunc_store_time, &ad7766_trigger_handler, |
| 287 | &ad7766_buffer_setup_ops); |
| 288 | if (ret) |
| 289 | return ret; |
| 290 | |
Tang Bin | bd14556 | 2021-05-11 21:47:39 +0800 | [diff] [blame] | 291 | return devm_iio_device_register(&spi->dev, indio_dev); |
Lars-Peter Clausen | aa16c6b | 2016-09-23 17:19:44 +0200 | [diff] [blame] | 292 | } |
| 293 | |
| 294 | static const struct spi_device_id ad7766_id[] = { |
| 295 | {"ad7766", ID_AD7766}, |
| 296 | {"ad7766-1", ID_AD7766_1}, |
| 297 | {"ad7766-2", ID_AD7766_2}, |
| 298 | {"ad7767", ID_AD7766}, |
| 299 | {"ad7767-1", ID_AD7766_1}, |
| 300 | {"ad7767-2", ID_AD7766_2}, |
| 301 | {} |
| 302 | }; |
| 303 | MODULE_DEVICE_TABLE(spi, ad7766_id); |
| 304 | |
| 305 | static struct spi_driver ad7766_driver = { |
| 306 | .driver = { |
| 307 | .name = "ad7766", |
| 308 | }, |
| 309 | .probe = ad7766_probe, |
| 310 | .id_table = ad7766_id, |
| 311 | }; |
| 312 | module_spi_driver(ad7766_driver); |
| 313 | |
| 314 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); |
| 315 | MODULE_DESCRIPTION("Analog Devices AD7766 and AD7767 ADCs driver support"); |
| 316 | MODULE_LICENSE("GPL v2"); |