1 /* 2 * AD5624R, AD5644R, AD5664R Digital to analog convertors spi driver 3 * 4 * Copyright 2010-2011 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 19 #include <linux/iio/iio.h> 20 #include <linux/iio/sysfs.h> 21 22 #include "ad5624r.h" 23 24 static int ad5624r_spi_write(struct spi_device *spi, 25 u8 cmd, u8 addr, u16 val, u8 len) 26 { 27 u32 data; 28 u8 msg[3]; 29 30 /* 31 * The input shift register is 24 bits wide. The first two bits are 32 * don't care bits. The next three are the command bits, C2 to C0, 33 * followed by the 3-bit DAC address, A2 to A0, and then the 34 * 16-, 14-, 12-bit data-word. The data-word comprises the 16-, 35 * 14-, 12-bit input code followed by 0, 2, or 4 don't care bits, 36 * for the AD5664R, AD5644R, and AD5624R, respectively. 37 */ 38 data = (0 << 22) | (cmd << 19) | (addr << 16) | (val << (16 - len)); 39 msg[0] = data >> 16; 40 msg[1] = data >> 8; 41 msg[2] = data; 42 43 return spi_write(spi, msg, 3); 44 } 45 46 static int ad5624r_read_raw(struct iio_dev *indio_dev, 47 struct iio_chan_spec const *chan, 48 int *val, 49 int *val2, 50 long m) 51 { 52 struct ad5624r_state *st = iio_priv(indio_dev); 53 54 switch (m) { 55 case IIO_CHAN_INFO_SCALE: 56 *val = st->vref_mv; 57 *val2 = chan->scan_type.realbits; 58 return IIO_VAL_FRACTIONAL_LOG2; 59 } 60 return -EINVAL; 61 } 62 63 static int ad5624r_write_raw(struct iio_dev *indio_dev, 64 struct iio_chan_spec const *chan, 65 int val, 66 int val2, 67 long mask) 68 { 69 struct ad5624r_state *st = iio_priv(indio_dev); 70 int ret; 71 72 switch (mask) { 73 case IIO_CHAN_INFO_RAW: 74 if (val >= (1 << chan->scan_type.realbits) || val < 0) 75 return -EINVAL; 76 77 return ad5624r_spi_write(st->us, 78 AD5624R_CMD_WRITE_INPUT_N_UPDATE_N, 79 chan->address, val, 80 chan->scan_type.shift); 81 default: 82 ret = -EINVAL; 83 } 84 85 return -EINVAL; 86 } 87 88 static const char * const ad5624r_powerdown_modes[] = { 89 "1kohm_to_gnd", 90 "100kohm_to_gnd", 91 "three_state" 92 }; 93 94 static int ad5624r_get_powerdown_mode(struct iio_dev *indio_dev, 95 const struct iio_chan_spec *chan) 96 { 97 struct ad5624r_state *st = iio_priv(indio_dev); 98 99 return st->pwr_down_mode; 100 } 101 102 static int ad5624r_set_powerdown_mode(struct iio_dev *indio_dev, 103 const struct iio_chan_spec *chan, unsigned int mode) 104 { 105 struct ad5624r_state *st = iio_priv(indio_dev); 106 107 st->pwr_down_mode = mode; 108 109 return 0; 110 } 111 112 static const struct iio_enum ad5624r_powerdown_mode_enum = { 113 .items = ad5624r_powerdown_modes, 114 .num_items = ARRAY_SIZE(ad5624r_powerdown_modes), 115 .get = ad5624r_get_powerdown_mode, 116 .set = ad5624r_set_powerdown_mode, 117 }; 118 119 static ssize_t ad5624r_read_dac_powerdown(struct iio_dev *indio_dev, 120 uintptr_t private, const struct iio_chan_spec *chan, char *buf) 121 { 122 struct ad5624r_state *st = iio_priv(indio_dev); 123 124 return sprintf(buf, "%d\n", 125 !!(st->pwr_down_mask & (1 << chan->channel))); 126 } 127 128 static ssize_t ad5624r_write_dac_powerdown(struct iio_dev *indio_dev, 129 uintptr_t private, const struct iio_chan_spec *chan, const char *buf, 130 size_t len) 131 { 132 bool pwr_down; 133 int ret; 134 struct ad5624r_state *st = iio_priv(indio_dev); 135 136 ret = strtobool(buf, &pwr_down); 137 if (ret) 138 return ret; 139 140 if (pwr_down) 141 st->pwr_down_mask |= (1 << chan->channel); 142 else 143 st->pwr_down_mask &= ~(1 << chan->channel); 144 145 ret = ad5624r_spi_write(st->us, AD5624R_CMD_POWERDOWN_DAC, 0, 146 (st->pwr_down_mode << 4) | 147 st->pwr_down_mask, 16); 148 149 return ret ? ret : len; 150 } 151 152 static const struct iio_info ad5624r_info = { 153 .write_raw = ad5624r_write_raw, 154 .read_raw = ad5624r_read_raw, 155 .driver_module = THIS_MODULE, 156 }; 157 158 static const struct iio_chan_spec_ext_info ad5624r_ext_info[] = { 159 { 160 .name = "powerdown", 161 .read = ad5624r_read_dac_powerdown, 162 .write = ad5624r_write_dac_powerdown, 163 .shared = IIO_SEPARATE, 164 }, 165 IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, 166 &ad5624r_powerdown_mode_enum), 167 IIO_ENUM_AVAILABLE("powerdown_mode", &ad5624r_powerdown_mode_enum), 168 { }, 169 }; 170 171 #define AD5624R_CHANNEL(_chan, _bits) { \ 172 .type = IIO_VOLTAGE, \ 173 .indexed = 1, \ 174 .output = 1, \ 175 .channel = (_chan), \ 176 .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ 177 .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \ 178 .address = (_chan), \ 179 .scan_type = IIO_ST('u', (_bits), 16, 16 - (_bits)), \ 180 .ext_info = ad5624r_ext_info, \ 181 } 182 183 #define DECLARE_AD5624R_CHANNELS(_name, _bits) \ 184 const struct iio_chan_spec _name##_channels[] = { \ 185 AD5624R_CHANNEL(0, _bits), \ 186 AD5624R_CHANNEL(1, _bits), \ 187 AD5624R_CHANNEL(2, _bits), \ 188 AD5624R_CHANNEL(3, _bits), \ 189 } 190 191 static DECLARE_AD5624R_CHANNELS(ad5624r, 12); 192 static DECLARE_AD5624R_CHANNELS(ad5644r, 14); 193 static DECLARE_AD5624R_CHANNELS(ad5664r, 16); 194 195 static const struct ad5624r_chip_info ad5624r_chip_info_tbl[] = { 196 [ID_AD5624R3] = { 197 .channels = ad5624r_channels, 198 .int_vref_mv = 1250, 199 }, 200 [ID_AD5624R5] = { 201 .channels = ad5624r_channels, 202 .int_vref_mv = 2500, 203 }, 204 [ID_AD5644R3] = { 205 .channels = ad5644r_channels, 206 .int_vref_mv = 1250, 207 }, 208 [ID_AD5644R5] = { 209 .channels = ad5644r_channels, 210 .int_vref_mv = 2500, 211 }, 212 [ID_AD5664R3] = { 213 .channels = ad5664r_channels, 214 .int_vref_mv = 1250, 215 }, 216 [ID_AD5664R5] = { 217 .channels = ad5664r_channels, 218 .int_vref_mv = 2500, 219 }, 220 }; 221 222 static int ad5624r_probe(struct spi_device *spi) 223 { 224 struct ad5624r_state *st; 225 struct iio_dev *indio_dev; 226 int ret, voltage_uv = 0; 227 228 indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); 229 if (!indio_dev) 230 return -ENOMEM; 231 st = iio_priv(indio_dev); 232 st->reg = devm_regulator_get(&spi->dev, "vcc"); 233 if (!IS_ERR(st->reg)) { 234 ret = regulator_enable(st->reg); 235 if (ret) 236 return ret; 237 238 ret = regulator_get_voltage(st->reg); 239 if (ret < 0) 240 goto error_disable_reg; 241 242 voltage_uv = ret; 243 } 244 245 spi_set_drvdata(spi, indio_dev); 246 st->chip_info = 247 &ad5624r_chip_info_tbl[spi_get_device_id(spi)->driver_data]; 248 249 if (voltage_uv) 250 st->vref_mv = voltage_uv / 1000; 251 else 252 st->vref_mv = st->chip_info->int_vref_mv; 253 254 st->us = spi; 255 256 indio_dev->dev.parent = &spi->dev; 257 indio_dev->name = spi_get_device_id(spi)->name; 258 indio_dev->info = &ad5624r_info; 259 indio_dev->modes = INDIO_DIRECT_MODE; 260 indio_dev->channels = st->chip_info->channels; 261 indio_dev->num_channels = AD5624R_DAC_CHANNELS; 262 263 ret = ad5624r_spi_write(spi, AD5624R_CMD_INTERNAL_REFER_SETUP, 0, 264 !!voltage_uv, 16); 265 if (ret) 266 goto error_disable_reg; 267 268 ret = iio_device_register(indio_dev); 269 if (ret) 270 goto error_disable_reg; 271 272 return 0; 273 274 error_disable_reg: 275 if (!IS_ERR(st->reg)) 276 regulator_disable(st->reg); 277 278 return ret; 279 } 280 281 static int ad5624r_remove(struct spi_device *spi) 282 { 283 struct iio_dev *indio_dev = spi_get_drvdata(spi); 284 struct ad5624r_state *st = iio_priv(indio_dev); 285 286 iio_device_unregister(indio_dev); 287 if (!IS_ERR(st->reg)) 288 regulator_disable(st->reg); 289 290 return 0; 291 } 292 293 static const struct spi_device_id ad5624r_id[] = { 294 {"ad5624r3", ID_AD5624R3}, 295 {"ad5644r3", ID_AD5644R3}, 296 {"ad5664r3", ID_AD5664R3}, 297 {"ad5624r5", ID_AD5624R5}, 298 {"ad5644r5", ID_AD5644R5}, 299 {"ad5664r5", ID_AD5664R5}, 300 {} 301 }; 302 MODULE_DEVICE_TABLE(spi, ad5624r_id); 303 304 static struct spi_driver ad5624r_driver = { 305 .driver = { 306 .name = "ad5624r", 307 .owner = THIS_MODULE, 308 }, 309 .probe = ad5624r_probe, 310 .remove = ad5624r_remove, 311 .id_table = ad5624r_id, 312 }; 313 module_spi_driver(ad5624r_driver); 314 315 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>"); 316 MODULE_DESCRIPTION("Analog Devices AD5624/44/64R DAC spi driver"); 317 MODULE_LICENSE("GPL v2"); 318