Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 1 | /* |
| 2 | * AD7303 Digital to analog converters driver |
| 3 | * |
| 4 | * Copyright 2013 Analog Devices Inc. |
| 5 | * |
| 6 | * Licensed under the GPL-2. |
| 7 | */ |
| 8 | |
| 9 | #include <linux/err.h> |
| 10 | #include <linux/module.h> |
| 11 | #include <linux/kernel.h> |
| 12 | #include <linux/spi/spi.h> |
| 13 | #include <linux/slab.h> |
| 14 | #include <linux/sysfs.h> |
| 15 | #include <linux/regulator/consumer.h> |
| 16 | #include <linux/of.h> |
| 17 | |
| 18 | #include <linux/iio/iio.h> |
| 19 | #include <linux/iio/sysfs.h> |
| 20 | |
| 21 | #include <linux/platform_data/ad7303.h> |
| 22 | |
| 23 | #define AD7303_CFG_EXTERNAL_VREF BIT(15) |
| 24 | #define AD7303_CFG_POWER_DOWN(ch) BIT(11 + (ch)) |
| 25 | #define AD7303_CFG_ADDR_OFFSET 10 |
| 26 | |
| 27 | #define AD7303_CMD_UPDATE_DAC (0x3 << 8) |
| 28 | |
| 29 | /** |
| 30 | * struct ad7303_state - driver instance specific data |
| 31 | * @spi: the device for this driver instance |
| 32 | * @config: cached config register value |
| 33 | * @dac_cache: current DAC raw value (chip does not support readback) |
| 34 | * @data: spi transfer buffer |
| 35 | */ |
| 36 | |
| 37 | struct ad7303_state { |
| 38 | struct spi_device *spi; |
| 39 | uint16_t config; |
| 40 | uint8_t dac_cache[2]; |
| 41 | |
| 42 | struct regulator *vdd_reg; |
| 43 | struct regulator *vref_reg; |
| 44 | |
| 45 | /* |
| 46 | * DMA (thus cache coherency maintenance) requires the |
| 47 | * transfer buffers to live in their own cache lines. |
| 48 | */ |
| 49 | __be16 data ____cacheline_aligned; |
| 50 | }; |
| 51 | |
| 52 | static int ad7303_write(struct ad7303_state *st, unsigned int chan, |
| 53 | uint8_t val) |
| 54 | { |
| 55 | st->data = cpu_to_be16(AD7303_CMD_UPDATE_DAC | |
| 56 | (chan << AD7303_CFG_ADDR_OFFSET) | |
| 57 | st->config | val); |
| 58 | |
| 59 | return spi_write(st->spi, &st->data, sizeof(st->data)); |
| 60 | } |
| 61 | |
| 62 | static ssize_t ad7303_read_dac_powerdown(struct iio_dev *indio_dev, |
| 63 | uintptr_t private, const struct iio_chan_spec *chan, char *buf) |
| 64 | { |
| 65 | struct ad7303_state *st = iio_priv(indio_dev); |
| 66 | |
| 67 | return sprintf(buf, "%d\n", (bool)(st->config & |
| 68 | AD7303_CFG_POWER_DOWN(chan->channel))); |
| 69 | } |
| 70 | |
| 71 | static ssize_t ad7303_write_dac_powerdown(struct iio_dev *indio_dev, |
| 72 | uintptr_t private, const struct iio_chan_spec *chan, const char *buf, |
| 73 | size_t len) |
| 74 | { |
| 75 | struct ad7303_state *st = iio_priv(indio_dev); |
| 76 | bool pwr_down; |
| 77 | int ret; |
| 78 | |
| 79 | ret = strtobool(buf, &pwr_down); |
| 80 | if (ret) |
| 81 | return ret; |
| 82 | |
| 83 | mutex_lock(&indio_dev->mlock); |
| 84 | |
| 85 | if (pwr_down) |
| 86 | st->config |= AD7303_CFG_POWER_DOWN(chan->channel); |
| 87 | else |
| 88 | st->config &= ~AD7303_CFG_POWER_DOWN(chan->channel); |
| 89 | |
| 90 | /* There is no noop cmd which allows us to only update the powerdown |
| 91 | * mode, so just write one of the DAC channels again */ |
| 92 | ad7303_write(st, chan->channel, st->dac_cache[chan->channel]); |
| 93 | |
| 94 | mutex_unlock(&indio_dev->mlock); |
Dan Carpenter | a04cf55 | 2014-01-30 11:58:00 +0000 | [diff] [blame] | 95 | return len; |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 96 | } |
| 97 | |
| 98 | static int ad7303_get_vref(struct ad7303_state *st, |
| 99 | struct iio_chan_spec const *chan) |
| 100 | { |
| 101 | int ret; |
| 102 | |
| 103 | if (st->config & AD7303_CFG_EXTERNAL_VREF) |
| 104 | return regulator_get_voltage(st->vref_reg); |
| 105 | |
| 106 | ret = regulator_get_voltage(st->vdd_reg); |
| 107 | if (ret < 0) |
| 108 | return ret; |
| 109 | return ret / 2; |
| 110 | } |
| 111 | |
| 112 | static int ad7303_read_raw(struct iio_dev *indio_dev, |
| 113 | struct iio_chan_spec const *chan, int *val, int *val2, long info) |
| 114 | { |
| 115 | struct ad7303_state *st = iio_priv(indio_dev); |
| 116 | int vref_uv; |
| 117 | |
| 118 | switch (info) { |
| 119 | case IIO_CHAN_INFO_RAW: |
| 120 | *val = st->dac_cache[chan->channel]; |
| 121 | return IIO_VAL_INT; |
| 122 | case IIO_CHAN_INFO_SCALE: |
| 123 | vref_uv = ad7303_get_vref(st, chan); |
| 124 | if (vref_uv < 0) |
| 125 | return vref_uv; |
| 126 | |
| 127 | *val = 2 * vref_uv / 1000; |
| 128 | *val2 = chan->scan_type.realbits; |
| 129 | |
| 130 | return IIO_VAL_FRACTIONAL_LOG2; |
| 131 | default: |
| 132 | break; |
| 133 | } |
| 134 | return -EINVAL; |
| 135 | } |
| 136 | |
| 137 | static int ad7303_write_raw(struct iio_dev *indio_dev, |
| 138 | struct iio_chan_spec const *chan, int val, int val2, long mask) |
| 139 | { |
| 140 | struct ad7303_state *st = iio_priv(indio_dev); |
| 141 | int ret; |
| 142 | |
| 143 | switch (mask) { |
| 144 | case IIO_CHAN_INFO_RAW: |
| 145 | if (val >= (1 << chan->scan_type.realbits) || val < 0) |
| 146 | return -EINVAL; |
| 147 | |
| 148 | mutex_lock(&indio_dev->mlock); |
| 149 | ret = ad7303_write(st, chan->address, val); |
| 150 | if (ret == 0) |
| 151 | st->dac_cache[chan->channel] = val; |
| 152 | mutex_unlock(&indio_dev->mlock); |
| 153 | break; |
| 154 | default: |
| 155 | ret = -EINVAL; |
| 156 | } |
| 157 | |
| 158 | return ret; |
| 159 | } |
| 160 | |
| 161 | static const struct iio_info ad7303_info = { |
| 162 | .read_raw = ad7303_read_raw, |
| 163 | .write_raw = ad7303_write_raw, |
| 164 | .driver_module = THIS_MODULE, |
| 165 | }; |
| 166 | |
| 167 | static const struct iio_chan_spec_ext_info ad7303_ext_info[] = { |
| 168 | { |
| 169 | .name = "powerdown", |
| 170 | .read = ad7303_read_dac_powerdown, |
| 171 | .write = ad7303_write_dac_powerdown, |
Jonathan Cameron | 3704432 | 2013-09-08 14:57:00 +0100 | [diff] [blame] | 172 | .shared = IIO_SEPARATE, |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 173 | }, |
| 174 | { }, |
| 175 | }; |
| 176 | |
| 177 | #define AD7303_CHANNEL(chan) { \ |
| 178 | .type = IIO_VOLTAGE, \ |
| 179 | .indexed = 1, \ |
| 180 | .output = 1, \ |
| 181 | .channel = (chan), \ |
| 182 | .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ |
| 183 | .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ |
| 184 | .address = (chan), \ |
| 185 | .scan_type = { \ |
| 186 | .sign = 'u', \ |
| 187 | .realbits = '8', \ |
| 188 | .storagebits = '8', \ |
| 189 | .shift = '0', \ |
| 190 | }, \ |
| 191 | .ext_info = ad7303_ext_info, \ |
| 192 | } |
| 193 | |
| 194 | static const struct iio_chan_spec ad7303_channels[] = { |
| 195 | AD7303_CHANNEL(0), |
| 196 | AD7303_CHANNEL(1), |
| 197 | }; |
| 198 | |
| 199 | static int ad7303_probe(struct spi_device *spi) |
| 200 | { |
| 201 | const struct spi_device_id *id = spi_get_device_id(spi); |
| 202 | struct iio_dev *indio_dev; |
| 203 | struct ad7303_state *st; |
| 204 | bool ext_ref; |
| 205 | int ret; |
| 206 | |
Sachin Kamat | 66e670aa | 2013-08-19 12:38:00 +0100 | [diff] [blame] | 207 | indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 208 | if (indio_dev == NULL) |
| 209 | return -ENOMEM; |
| 210 | |
| 211 | st = iio_priv(indio_dev); |
| 212 | spi_set_drvdata(spi, indio_dev); |
| 213 | |
| 214 | st->spi = spi; |
| 215 | |
Sachin Kamat | 66e670aa | 2013-08-19 12:38:00 +0100 | [diff] [blame] | 216 | st->vdd_reg = devm_regulator_get(&spi->dev, "Vdd"); |
| 217 | if (IS_ERR(st->vdd_reg)) |
| 218 | return PTR_ERR(st->vdd_reg); |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 219 | |
| 220 | ret = regulator_enable(st->vdd_reg); |
| 221 | if (ret) |
Sachin Kamat | 66e670aa | 2013-08-19 12:38:00 +0100 | [diff] [blame] | 222 | return ret; |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 223 | |
| 224 | if (spi->dev.of_node) { |
| 225 | ext_ref = of_property_read_bool(spi->dev.of_node, |
| 226 | "REF-supply"); |
| 227 | } else { |
| 228 | struct ad7303_platform_data *pdata = spi->dev.platform_data; |
| 229 | if (pdata && pdata->use_external_ref) |
| 230 | ext_ref = true; |
| 231 | else |
| 232 | ext_ref = false; |
| 233 | } |
| 234 | |
| 235 | if (ext_ref) { |
Sachin Kamat | 66e670aa | 2013-08-19 12:38:00 +0100 | [diff] [blame] | 236 | st->vref_reg = devm_regulator_get(&spi->dev, "REF"); |
Wei Yongjun | 94fccb7 | 2013-06-18 14:08:00 +0100 | [diff] [blame] | 237 | if (IS_ERR(st->vref_reg)) { |
| 238 | ret = PTR_ERR(st->vref_reg); |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 239 | goto err_disable_vdd_reg; |
Wei Yongjun | 94fccb7 | 2013-06-18 14:08:00 +0100 | [diff] [blame] | 240 | } |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 241 | |
| 242 | ret = regulator_enable(st->vref_reg); |
| 243 | if (ret) |
Sachin Kamat | 66e670aa | 2013-08-19 12:38:00 +0100 | [diff] [blame] | 244 | goto err_disable_vdd_reg; |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 245 | |
| 246 | st->config |= AD7303_CFG_EXTERNAL_VREF; |
| 247 | } |
| 248 | |
| 249 | indio_dev->dev.parent = &spi->dev; |
| 250 | indio_dev->name = id->name; |
| 251 | indio_dev->info = &ad7303_info; |
| 252 | indio_dev->modes = INDIO_DIRECT_MODE; |
| 253 | indio_dev->channels = ad7303_channels; |
| 254 | indio_dev->num_channels = ARRAY_SIZE(ad7303_channels); |
| 255 | |
| 256 | ret = iio_device_register(indio_dev); |
| 257 | if (ret) |
| 258 | goto err_disable_vref_reg; |
| 259 | |
| 260 | return 0; |
| 261 | |
| 262 | err_disable_vref_reg: |
| 263 | if (st->vref_reg) |
| 264 | regulator_disable(st->vref_reg); |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 265 | err_disable_vdd_reg: |
| 266 | regulator_disable(st->vdd_reg); |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 267 | return ret; |
| 268 | } |
| 269 | |
| 270 | static int ad7303_remove(struct spi_device *spi) |
| 271 | { |
| 272 | struct iio_dev *indio_dev = spi_get_drvdata(spi); |
| 273 | struct ad7303_state *st = iio_priv(indio_dev); |
| 274 | |
| 275 | iio_device_unregister(indio_dev); |
| 276 | |
Sachin Kamat | 66e670aa | 2013-08-19 12:38:00 +0100 | [diff] [blame] | 277 | if (st->vref_reg) |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 278 | regulator_disable(st->vref_reg); |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 279 | regulator_disable(st->vdd_reg); |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 280 | |
| 281 | return 0; |
| 282 | } |
| 283 | |
Javier Martinez Canillas | 1c00dcd | 2015-08-20 09:07:23 +0200 | [diff] [blame] | 284 | static const struct of_device_id ad7303_spi_of_match[] = { |
| 285 | { .compatible = "adi,ad7303", }, |
| 286 | { /* sentinel */ }, |
| 287 | }; |
| 288 | MODULE_DEVICE_TABLE(of, ad7303_spi_of_match); |
| 289 | |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 290 | static const struct spi_device_id ad7303_spi_ids[] = { |
| 291 | { "ad7303", 0 }, |
| 292 | {} |
| 293 | }; |
| 294 | MODULE_DEVICE_TABLE(spi, ad7303_spi_ids); |
| 295 | |
| 296 | static struct spi_driver ad7303_driver = { |
| 297 | .driver = { |
| 298 | .name = "ad7303", |
Javier Martinez Canillas | 1c00dcd | 2015-08-20 09:07:23 +0200 | [diff] [blame] | 299 | .of_match_table = of_match_ptr(ad7303_spi_of_match), |
Lars-Peter Clausen | f834782 | 2013-06-11 17:56:00 +0100 | [diff] [blame] | 300 | }, |
| 301 | .probe = ad7303_probe, |
| 302 | .remove = ad7303_remove, |
| 303 | .id_table = ad7303_spi_ids, |
| 304 | }; |
| 305 | module_spi_driver(ad7303_driver); |
| 306 | |
| 307 | MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>"); |
| 308 | MODULE_DESCRIPTION("Analog Devices AD7303 DAC driver"); |
| 309 | MODULE_LICENSE("GPL v2"); |