1 /* 2 * AD5504, AD5501 High Voltage Digital to Analog Converter 3 * 4 * Copyright 2011 Analog Devices Inc. 5 * 6 * Licensed under the GPL-2. 7 */ 8 9 #include <linux/interrupt.h> 10 #include <linux/fs.h> 11 #include <linux/device.h> 12 #include <linux/kernel.h> 13 #include <linux/spi/spi.h> 14 #include <linux/slab.h> 15 #include <linux/sysfs.h> 16 #include <linux/regulator/consumer.h> 17 #include <linux/module.h> 18 #include <linux/bitops.h> 19 20 #include <linux/iio/iio.h> 21 #include <linux/iio/sysfs.h> 22 #include <linux/iio/events.h> 23 #include <linux/iio/dac/ad5504.h> 24 25 #define AD5504_RES_MASK GENMASK(11, 0) 26 #define AD5504_CMD_READ BIT(15) 27 #define AD5504_CMD_WRITE 0 28 #define AD5504_ADDR(addr) ((addr) << 12) 29 30 /* Registers */ 31 #define AD5504_ADDR_NOOP 0 32 #define AD5504_ADDR_DAC(x) ((x) + 1) 33 #define AD5504_ADDR_ALL_DAC 5 34 #define AD5504_ADDR_CTRL 7 35 36 /* Control Register */ 37 #define AD5504_DAC_PWR(ch) ((ch) << 2) 38 #define AD5504_DAC_PWRDWN_MODE(mode) ((mode) << 6) 39 #define AD5504_DAC_PWRDN_20K 0 40 #define AD5504_DAC_PWRDN_3STATE 1 41 42 /** 43 * struct ad5446_state - driver instance specific data 44 * @spi: spi_device 45 * @reg: supply regulator 46 * @vref_mv: actual reference voltage used 47 * @pwr_down_mask power down mask 48 * @pwr_down_mode current power down mode 49 * @data: transfer buffer 50 */ 51 struct ad5504_state { 52 struct spi_device *spi; 53 struct regulator *reg; 54 unsigned short vref_mv; 55 unsigned pwr_down_mask; 56 unsigned pwr_down_mode; 57 58 __be16 data[2] ____cacheline_aligned; 59 }; 60 61 /** 62 * ad5504_supported_device_ids: 63 */ 64 65 enum ad5504_supported_device_ids { 66 ID_AD5504, 67 ID_AD5501, 68 }; 69 70 static int ad5504_spi_write(struct ad5504_state *st, u8 addr, u16 val) 71 { 72 st->data[0] = cpu_to_be16(AD5504_CMD_WRITE | AD5504_ADDR(addr) | 73 (val & AD5504_RES_MASK)); 74 75 return spi_write(st->spi, &st->data[0], 2); 76 } 77 78 static int ad5504_spi_read(struct ad5504_state *st, u8 addr) 79 { 80 int ret; 81 struct spi_transfer t = { 82 .tx_buf = &st->data[0], 83 .rx_buf = &st->data[1], 84 .len = 2, 85 }; 86 87 st->data[0] = cpu_to_be16(AD5504_CMD_READ | AD5504_ADDR(addr)); 88 ret = spi_sync_transfer(st->spi, &t, 1); 89 if (ret < 0) 90 return ret; 91 92 return be16_to_cpu(st->data[1]) & AD5504_RES_MASK; 93 } 94 95 static int ad5504_read_raw(struct iio_dev *indio_dev, 96 struct iio_chan_spec const *chan, 97 int *val, 98 int *val2, 99 long m) 100 { 101 struct ad5504_state *st = iio_priv(indio_dev); 102 int ret; 103 104 switch (m) { 105 case IIO_CHAN_INFO_RAW: 106 ret = ad5504_spi_read(st, chan->address); 107 if (ret < 0) 108 return ret; 109 110 *val = ret; 111 112 return IIO_VAL_INT; 113 case IIO_CHAN_INFO_SCALE: 114 *val = st->vref_mv; 115 *val2 = chan->scan_type.realbits; 116 return IIO_VAL_FRACTIONAL_LOG2; 117 } 118 return -EINVAL; 119 } 120 121 static int ad5504_write_raw(struct iio_dev *indio_dev, 122 struct iio_chan_spec const *chan, 123 int val, 124 int val2, 125 long mask) 126 { 127 struct ad5504_state *st = iio_priv(indio_dev); 128 129 switch (mask) { 130 case IIO_CHAN_INFO_RAW: 131 if (val >= (1 << chan->scan_type.realbits) || val < 0) 132 return -EINVAL; 133 134 return ad5504_spi_write(st, chan->address, val); 135 default: 136 return -EINVAL; 137 } 138 } 139 140 static const char * const ad5504_powerdown_modes[] = { 141 "20kohm_to_gnd", 142 "three_state", 143 }; 144 145 static int ad5504_get_powerdown_mode(struct iio_dev *indio_dev, 146 const struct iio_chan_spec *chan) 147 { 148 struct ad5504_state *st = iio_priv(indio_dev); 149 150 return st->pwr_down_mode; 151 } 152 153 static int ad5504_set_powerdown_mode(struct iio_dev *indio_dev, 154 const struct iio_chan_spec *chan, unsigned int mode) 155 { 156 struct ad5504_state *st = iio_priv(indio_dev); 157 158 st->pwr_down_mode = mode; 159 160 return 0; 161 } 162 163 static const struct iio_enum ad5504_powerdown_mode_enum = { 164 .items = ad5504_powerdown_modes, 165 .num_items = ARRAY_SIZE(ad5504_powerdown_modes), 166 .get = ad5504_get_powerdown_mode, 167 .set = ad5504_set_powerdown_mode, 168 }; 169 170 static ssize_t ad5504_read_dac_powerdown(struct iio_dev *indio_dev, 171 uintptr_t private, const struct iio_chan_spec *chan, char *buf) 172 { 173 struct ad5504_state *st = iio_priv(indio_dev); 174 175 return sprintf(buf, "%d\n", 176 !(st->pwr_down_mask & (1 << chan->channel))); 177 } 178 179 static ssize_t ad5504_write_dac_powerdown(struct iio_dev *indio_dev, 180 uintptr_t private, const struct iio_chan_spec *chan, const char *buf, 181 size_t len) 182 { 183 bool pwr_down; 184 int ret; 185 struct ad5504_state *st = iio_priv(indio_dev); 186 187 ret = strtobool(buf, &pwr_down); 188 if (ret) 189 return ret; 190 191 if (pwr_down) 192 st->pwr_down_mask |= (1 << chan->channel); 193 else 194 st->pwr_down_mask &= ~(1 << chan->channel); 195 196 ret = ad5504_spi_write(st, AD5504_ADDR_CTRL, 197 AD5504_DAC_PWRDWN_MODE(st->pwr_down_mode) | 198 AD5504_DAC_PWR(st->pwr_down_mask)); 199 200 /* writes to the CTRL register must be followed by a NOOP */ 201 ad5504_spi_write(st, AD5504_ADDR_NOOP, 0); 202 203 return ret ? ret : len; 204 } 205 206 static IIO_CONST_ATTR(temp0_thresh_rising_value, "110000"); 207 static IIO_CONST_ATTR(temp0_thresh_rising_en, "1"); 208 209 static struct attribute *ad5504_ev_attributes[] = { 210 &iio_const_attr_temp0_thresh_rising_value.dev_attr.attr, 211 &iio_const_attr_temp0_thresh_rising_en.dev_attr.attr, 212 NULL, 213 }; 214 215 static const struct attribute_group ad5504_ev_attribute_group = { 216 .attrs = ad5504_ev_attributes, 217 }; 218 219 static irqreturn_t ad5504_event_handler(int irq, void *private) 220 { 221 iio_push_event(private, 222 IIO_UNMOD_EVENT_CODE(IIO_TEMP, 223 0, 224 IIO_EV_TYPE_THRESH, 225 IIO_EV_DIR_RISING), 226 iio_get_time_ns(private)); 227 228 return IRQ_HANDLED; 229 } 230 231 static const struct iio_info ad5504_info = { 232 .write_raw = ad5504_write_raw, 233 .read_raw = ad5504_read_raw, 234 .event_attrs = &ad5504_ev_attribute_group, 235 }; 236 237 static const struct iio_chan_spec_ext_info ad5504_ext_info[] = { 238 { 239 .name = "powerdown", 240 .read = ad5504_read_dac_powerdown, 241 .write = ad5504_write_dac_powerdown, 242 .shared = IIO_SEPARATE, 243 }, 244 IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, 245 &ad5504_powerdown_mode_enum), 246 IIO_ENUM_AVAILABLE("powerdown_mode", &ad5504_powerdown_mode_enum), 247 { }, 248 }; 249 250 #define AD5504_CHANNEL(_chan) { \ 251 .type = IIO_VOLTAGE, \ 252 .indexed = 1, \ 253 .output = 1, \ 254 .channel = (_chan), \ 255 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 256 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 257 .address = AD5504_ADDR_DAC(_chan), \ 258 .scan_type = { \ 259 .sign = 'u', \ 260 .realbits = 12, \ 261 .storagebits = 16, \ 262 }, \ 263 .ext_info = ad5504_ext_info, \ 264 } 265 266 static const struct iio_chan_spec ad5504_channels[] = { 267 AD5504_CHANNEL(0), 268 AD5504_CHANNEL(1), 269 AD5504_CHANNEL(2), 270 AD5504_CHANNEL(3), 271 }; 272 273 static int ad5504_probe(struct spi_device *spi) 274 { 275 struct ad5504_platform_data *pdata = spi->dev.platform_data; 276 struct iio_dev *indio_dev; 277 struct ad5504_state *st; 278 struct regulator *reg; 279 int ret, voltage_uv = 0; 280 281 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 282 if (!indio_dev) 283 return -ENOMEM; 284 reg = devm_regulator_get(&spi->dev, "vcc"); 285 if (!IS_ERR(reg)) { 286 ret = regulator_enable(reg); 287 if (ret) 288 return ret; 289 290 ret = regulator_get_voltage(reg); 291 if (ret < 0) 292 goto error_disable_reg; 293 294 voltage_uv = ret; 295 } 296 297 spi_set_drvdata(spi, indio_dev); 298 st = iio_priv(indio_dev); 299 if (voltage_uv) 300 st->vref_mv = voltage_uv / 1000; 301 else if (pdata) 302 st->vref_mv = pdata->vref_mv; 303 else 304 dev_warn(&spi->dev, "reference voltage unspecified\n"); 305 306 st->reg = reg; 307 st->spi = spi; 308 indio_dev->dev.parent = &spi->dev; 309 indio_dev->name = spi_get_device_id(st->spi)->name; 310 indio_dev->info = &ad5504_info; 311 if (spi_get_device_id(st->spi)->driver_data == ID_AD5501) 312 indio_dev->num_channels = 1; 313 else 314 indio_dev->num_channels = 4; 315 indio_dev->channels = ad5504_channels; 316 indio_dev->modes = INDIO_DIRECT_MODE; 317 318 if (spi->irq) { 319 ret = devm_request_threaded_irq(&spi->dev, spi->irq, 320 NULL, 321 &ad5504_event_handler, 322 IRQF_TRIGGER_FALLING | IRQF_ONESHOT, 323 spi_get_device_id(st->spi)->name, 324 indio_dev); 325 if (ret) 326 goto error_disable_reg; 327 } 328 329 ret = iio_device_register(indio_dev); 330 if (ret) 331 goto error_disable_reg; 332 333 return 0; 334 335 error_disable_reg: 336 if (!IS_ERR(reg)) 337 regulator_disable(reg); 338 339 return ret; 340 } 341 342 static int ad5504_remove(struct spi_device *spi) 343 { 344 struct iio_dev *indio_dev = spi_get_drvdata(spi); 345 struct ad5504_state *st = iio_priv(indio_dev); 346 347 iio_device_unregister(indio_dev); 348 349 if (!IS_ERR(st->reg)) 350 regulator_disable(st->reg); 351 352 return 0; 353 } 354 355 static const struct spi_device_id ad5504_id[] = { 356 {"ad5504", ID_AD5504}, 357 {"ad5501", ID_AD5501}, 358 {} 359 }; 360 MODULE_DEVICE_TABLE(spi, ad5504_id); 361 362 static struct spi_driver ad5504_driver = { 363 .driver = { 364 .name = "ad5504", 365 }, 366 .probe = ad5504_probe, 367 .remove = ad5504_remove, 368 .id_table = ad5504_id, 369 }; 370 module_spi_driver(ad5504_driver); 371 372 MODULE_AUTHOR("Michael Hennerich <hennerich@blackfin.uclinux.org>"); 373 MODULE_DESCRIPTION("Analog Devices AD5501/AD5501 DAC"); 374 MODULE_LICENSE("GPL v2"); 375