iio/dac/ad5624r_spi.c

0001 // SPDX-License-Identifier: GPL-2.0-only
0002 /*
0003  * AD5624R, AD5644R, AD5664R Digital to analog convertors spi driver
0004  *
0005  * Copyright 2010-2011 Analog Devices Inc.
0006  */
0007
0008 #include <linux/interrupt.h>
0009 #include <linux/fs.h>
0010 #include <linux/device.h>
0011 #include <linux/kernel.h>
0012 #include <linux/spi/spi.h>
0013 #include <linux/slab.h>
0014 #include <linux/sysfs.h>
0015 #include <linux/regulator/consumer.h>
0016 #include <linux/module.h>
0017
0018 #include <linux/iio/iio.h>
0019 #include <linux/iio/sysfs.h>
0020
0021 #include <asm/unaligned.h>
0022
0023 #include "ad5624r.h"
0024
0025 static int ad5624r_spi_write(struct spi_device *spi,
0026                  u8 cmd, u8 addr, u16 val, u8 shift)
0027 {
0028     u32 data;
0029     u8 msg[3];
0030
0031     /*
0032      * The input shift register is 24 bits wide. The first two bits are
0033      * don't care bits. The next three are the command bits, C2 to C0,
0034      * followed by the 3-bit DAC address, A2 to A0, and then the
0035      * 16-, 14-, 12-bit data-word. The data-word comprises the 16-,
0036      * 14-, 12-bit input code followed by 0, 2, or 4 don't care bits,
0037      * for the AD5664R, AD5644R, and AD5624R, respectively.
0038      */
0039     data = (0 << 22) | (cmd << 19) | (addr << 16) | (val << shift);
0040     put_unaligned_be24(data, &msg[0]);
0041
0042     return spi_write(spi, msg, sizeof(msg));
0043 }
0044
0045 static int ad5624r_read_raw(struct iio_dev *indio_dev,
0046                struct iio_chan_spec const *chan,
0047                int *val,
0048                int *val2,
0049                long m)
0050 {
0051     struct ad5624r_state *st = iio_priv(indio_dev);
0052
0053     switch (m) {
0054     case IIO_CHAN_INFO_SCALE:
0055         *val = st->vref_mv;
0056         *val2 = chan->scan_type.realbits;
0057         return IIO_VAL_FRACTIONAL_LOG2;
0058     }
0059     return -EINVAL;
0060 }
0061
0062 static int ad5624r_write_raw(struct iio_dev *indio_dev,
0063                    struct iio_chan_spec const *chan,
0064                    int val,
0065                    int val2,
0066                    long mask)
0067 {
0068     struct ad5624r_state *st = iio_priv(indio_dev);
0069
0070     switch (mask) {
0071     case IIO_CHAN_INFO_RAW:
0072         if (val >= (1 << chan->scan_type.realbits) || val < 0)
0073             return -EINVAL;
0074
0075         return ad5624r_spi_write(st->us,
0076                 AD5624R_CMD_WRITE_INPUT_N_UPDATE_N,
0077                 chan->address, val,
0078                 chan->scan_type.shift);
0079     default:
0080         return -EINVAL;
0081     }
0082 }
0083
0084 static const char * const ad5624r_powerdown_modes[] = {
0085     "1kohm_to_gnd",
0086     "100kohm_to_gnd",
0087     "three_state"
0088 };
0089
0090 static int ad5624r_get_powerdown_mode(struct iio_dev *indio_dev,
0091     const struct iio_chan_spec *chan)
0092 {
0093     struct ad5624r_state *st = iio_priv(indio_dev);
0094
0095     return st->pwr_down_mode;
0096 }
0097
0098 static int ad5624r_set_powerdown_mode(struct iio_dev *indio_dev,
0099     const struct iio_chan_spec *chan, unsigned int mode)
0100 {
0101     struct ad5624r_state *st = iio_priv(indio_dev);
0102
0103     st->pwr_down_mode = mode;
0104
0105     return 0;
0106 }
0107
0108 static const struct iio_enum ad5624r_powerdown_mode_enum = {
0109     .items = ad5624r_powerdown_modes,
0110     .num_items = ARRAY_SIZE(ad5624r_powerdown_modes),
0111     .get = ad5624r_get_powerdown_mode,
0112     .set = ad5624r_set_powerdown_mode,
0113 };
0114
0115 static ssize_t ad5624r_read_dac_powerdown(struct iio_dev *indio_dev,
0116     uintptr_t private, const struct iio_chan_spec *chan, char *buf)
0117 {
0118     struct ad5624r_state *st = iio_priv(indio_dev);
0119
0120     return sysfs_emit(buf, "%d\n",
0121               !!(st->pwr_down_mask & (1 << chan->channel)));
0122 }
0123
0124 static ssize_t ad5624r_write_dac_powerdown(struct iio_dev *indio_dev,
0125     uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
0126     size_t len)
0127 {
0128     bool pwr_down;
0129     int ret;
0130     struct ad5624r_state *st = iio_priv(indio_dev);
0131
0132     ret = kstrtobool(buf, &pwr_down);
0133     if (ret)
0134         return ret;
0135
0136     if (pwr_down)
0137         st->pwr_down_mask |= (1 << chan->channel);
0138     else
0139         st->pwr_down_mask &= ~(1 << chan->channel);
0140
0141     ret = ad5624r_spi_write(st->us, AD5624R_CMD_POWERDOWN_DAC, 0,
0142                 (st->pwr_down_mode << 4) |
0143                 st->pwr_down_mask, 16);
0144
0145     return ret ? ret : len;
0146 }
0147
0148 static const struct iio_info ad5624r_info = {
0149     .write_raw = ad5624r_write_raw,
0150     .read_raw = ad5624r_read_raw,
0151 };
0152
0153 static const struct iio_chan_spec_ext_info ad5624r_ext_info[] = {
0154     {
0155         .name = "powerdown",
0156         .read = ad5624r_read_dac_powerdown,
0157         .write = ad5624r_write_dac_powerdown,
0158         .shared = IIO_SEPARATE,
0159     },
0160     IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE,
0161          &ad5624r_powerdown_mode_enum),
0162     IIO_ENUM_AVAILABLE("powerdown_mode", IIO_SHARED_BY_TYPE, &ad5624r_powerdown_mode_enum),
0163     { },
0164 };
0165
0166 #define AD5624R_CHANNEL(_chan, _bits) { \
0167     .type = IIO_VOLTAGE, \
0168     .indexed = 1, \
0169     .output = 1, \
0170     .channel = (_chan), \
0171     .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
0172     .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
0173     .address = (_chan), \
0174     .scan_type = { \
0175         .sign = 'u', \
0176         .realbits = (_bits), \
0177         .storagebits = 16, \
0178         .shift = 16 - (_bits), \
0179     }, \
0180     .ext_info = ad5624r_ext_info, \
0181 }
0182
0183 #define DECLARE_AD5624R_CHANNELS(_name, _bits) \
0184     const struct iio_chan_spec _name##_channels[] = { \
0185         AD5624R_CHANNEL(0, _bits), \
0186         AD5624R_CHANNEL(1, _bits), \
0187         AD5624R_CHANNEL(2, _bits), \
0188         AD5624R_CHANNEL(3, _bits), \
0189 }
0190
0191 static DECLARE_AD5624R_CHANNELS(ad5624r, 12);
0192 static DECLARE_AD5624R_CHANNELS(ad5644r, 14);
0193 static DECLARE_AD5624R_CHANNELS(ad5664r, 16);
0194
0195 static const struct ad5624r_chip_info ad5624r_chip_info_tbl[] = {
0196     [ID_AD5624R3] = {
0197         .channels = ad5624r_channels,
0198         .int_vref_mv = 1250,
0199     },
0200     [ID_AD5624R5] = {
0201         .channels = ad5624r_channels,
0202         .int_vref_mv = 2500,
0203     },
0204     [ID_AD5644R3] = {
0205         .channels = ad5644r_channels,
0206         .int_vref_mv = 1250,
0207     },
0208     [ID_AD5644R5] = {
0209         .channels = ad5644r_channels,
0210         .int_vref_mv = 2500,
0211     },
0212     [ID_AD5664R3] = {
0213         .channels = ad5664r_channels,
0214         .int_vref_mv = 1250,
0215     },
0216     [ID_AD5664R5] = {
0217         .channels = ad5664r_channels,
0218         .int_vref_mv = 2500,
0219     },
0220 };
0221
0222 static int ad5624r_probe(struct spi_device *spi)
0223 {
0224     struct ad5624r_state *st;
0225     struct iio_dev *indio_dev;
0226     int ret, voltage_uv = 0;
0227
0228     indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
0229     if (!indio_dev)
0230         return -ENOMEM;
0231     st = iio_priv(indio_dev);
0232     st->reg = devm_regulator_get_optional(&spi->dev, "vref");
0233     if (!IS_ERR(st->reg)) {
0234         ret = regulator_enable(st->reg);
0235         if (ret)
0236             return ret;
0237
0238         ret = regulator_get_voltage(st->reg);
0239         if (ret < 0)
0240             goto error_disable_reg;
0241
0242         voltage_uv = ret;
0243     } else {
0244         if (PTR_ERR(st->reg) != -ENODEV)
0245             return PTR_ERR(st->reg);
0246         /* Backwards compatibility. This naming is not correct */
0247         st->reg = devm_regulator_get_optional(&spi->dev, "vcc");
0248         if (!IS_ERR(st->reg)) {
0249             ret = regulator_enable(st->reg);
0250             if (ret)
0251                 return ret;
0252
0253             ret = regulator_get_voltage(st->reg);
0254             if (ret < 0)
0255                 goto error_disable_reg;
0256
0257             voltage_uv = ret;
0258         }
0259     }
0260
0261     spi_set_drvdata(spi, indio_dev);
0262     st->chip_info =
0263         &ad5624r_chip_info_tbl[spi_get_device_id(spi)->driver_data];
0264
0265     if (voltage_uv)
0266         st->vref_mv = voltage_uv / 1000;
0267     else
0268         st->vref_mv = st->chip_info->int_vref_mv;
0269
0270     st->us = spi;
0271
0272     indio_dev->name = spi_get_device_id(spi)->name;
0273     indio_dev->info = &ad5624r_info;
0274     indio_dev->modes = INDIO_DIRECT_MODE;
0275     indio_dev->channels = st->chip_info->channels;
0276     indio_dev->num_channels = AD5624R_DAC_CHANNELS;
0277
0278     ret = ad5624r_spi_write(spi, AD5624R_CMD_INTERNAL_REFER_SETUP, 0,
0279                 !!voltage_uv, 16);
0280     if (ret)
0281         goto error_disable_reg;
0282
0283     ret = iio_device_register(indio_dev);
0284     if (ret)
0285         goto error_disable_reg;
0286
0287     return 0;
0288
0289 error_disable_reg:
0290     if (!IS_ERR(st->reg))
0291         regulator_disable(st->reg);
0292
0293     return ret;
0294 }
0295
0296 static void ad5624r_remove(struct spi_device *spi)
0297 {
0298     struct iio_dev *indio_dev = spi_get_drvdata(spi);
0299     struct ad5624r_state *st = iio_priv(indio_dev);
0300
0301     iio_device_unregister(indio_dev);
0302     if (!IS_ERR(st->reg))
0303         regulator_disable(st->reg);
0304 }
0305
0306 static const struct spi_device_id ad5624r_id[] = {
0307     {"ad5624r3", ID_AD5624R3},
0308     {"ad5644r3", ID_AD5644R3},
0309     {"ad5664r3", ID_AD5664R3},
0310     {"ad5624r5", ID_AD5624R5},
0311     {"ad5644r5", ID_AD5644R5},
0312     {"ad5664r5", ID_AD5664R5},
0313     {}
0314 };
0315 MODULE_DEVICE_TABLE(spi, ad5624r_id);
0316
0317 static struct spi_driver ad5624r_driver = {
0318     .driver = {
0319            .name = "ad5624r",
0320            },
0321     .probe = ad5624r_probe,
0322     .remove = ad5624r_remove,
0323     .id_table = ad5624r_id,
0324 };
0325 module_spi_driver(ad5624r_driver);
0326
0327 MODULE_AUTHOR("Barry Song <21cnbao@gmail.com>");
0328 MODULE_DESCRIPTION("Analog Devices AD5624/44/64R DAC spi driver");
0329 MODULE_LICENSE("GPL v2");