/* * AD5760, AD5780, AD5781, AD5790, AD5791 Voltage Output Digital to Analog * Converter * * Copyright 2011 Analog Devices Inc. * * Licensed under the GPL-2. */ #include <linux/interrupt.h> #include <linux/fs.h> #include <linux/device.h> #include <linux/kernel.h> #include <linux/spi/spi.h> #include <linux/slab.h> #include <linux/sysfs.h> #include <linux/regulator/consumer.h> #include <linux/module.h> #include <linux/bitops.h> #include <linux/iio/iio.h> #include <linux/iio/sysfs.h> #include <linux/iio/dac/ad5791.h> #define AD5791_DAC_MASK GENMASK(19, 0) #define AD5791_CMD_READ BIT(23) #define AD5791_CMD_WRITE 0 #define AD5791_ADDR(addr) ((addr) << 20) /* Registers */ #define AD5791_ADDR_NOOP 0 #define AD5791_ADDR_DAC0 1 #define AD5791_ADDR_CTRL 2 #define AD5791_ADDR_CLRCODE 3 #define AD5791_ADDR_SW_CTRL 4 /* Control Register */ #define AD5791_CTRL_RBUF BIT(1) #define AD5791_CTRL_OPGND BIT(2) #define AD5791_CTRL_DACTRI BIT(3) #define AD5791_CTRL_BIN2SC BIT(4) #define AD5791_CTRL_SDODIS BIT(5) #define AD5761_CTRL_LINCOMP(x) ((x) << 6) #define AD5791_LINCOMP_0_10 0 #define AD5791_LINCOMP_10_12 1 #define AD5791_LINCOMP_12_16 2 #define AD5791_LINCOMP_16_19 3 #define AD5791_LINCOMP_19_20 12 #define AD5780_LINCOMP_0_10 0 #define AD5780_LINCOMP_10_20 12 /* Software Control Register */ #define AD5791_SWCTRL_LDAC BIT(0) #define AD5791_SWCTRL_CLR BIT(1) #define AD5791_SWCTRL_RESET BIT(2) #define AD5791_DAC_PWRDN_6K 0 #define AD5791_DAC_PWRDN_3STATE 1 /** * struct ad5791_chip_info - chip specific information * @get_lin_comp: function pointer to the device specific function */ struct ad5791_chip_info { int (*get_lin_comp) (unsigned int span); }; /** * struct ad5791_state - driver instance specific data * @spi: spi_device * @reg_vdd: positive supply regulator * @reg_vss: negative supply regulator * @chip_info: chip model specific constants * @vref_mv: actual reference voltage used * @vref_neg_mv: voltage of the negative supply * @pwr_down_mode current power down mode */ struct ad5791_state { struct spi_device *spi; struct regulator *reg_vdd; struct regulator *reg_vss; const struct ad5791_chip_info *chip_info; unsigned short vref_mv; unsigned int vref_neg_mv; unsigned ctrl; unsigned pwr_down_mode; bool pwr_down; union { __be32 d32; u8 d8[4]; } data[3] ____cacheline_aligned; }; /** * ad5791_supported_device_ids: */ enum ad5791_supported_device_ids { ID_AD5760, ID_AD5780, ID_AD5781, ID_AD5791, }; static int ad5791_spi_write(struct ad5791_state *st, u8 addr, u32 val) { st->data[0].d32 = cpu_to_be32(AD5791_CMD_WRITE | AD5791_ADDR(addr) | (val & AD5791_DAC_MASK)); return spi_write(st->spi, &st->data[0].d8[1], 3); } static int ad5791_spi_read(struct ad5791_state *st, u8 addr, u32 *val) { int ret; struct spi_transfer xfers[] = { { .tx_buf = &st->data[0].d8[1], .bits_per_word = 8, .len = 3, .cs_change = 1, }, { .tx_buf = &st->data[1].d8[1], .rx_buf = &st->data[2].d8[1], .bits_per_word = 8, .len = 3, }, }; st->data[0].d32 = cpu_to_be32(AD5791_CMD_READ | AD5791_ADDR(addr)); st->data[1].d32 = cpu_to_be32(AD5791_ADDR(AD5791_ADDR_NOOP)); ret = spi_sync_transfer(st->spi, xfers, ARRAY_SIZE(xfers)); *val = be32_to_cpu(st->data[2].d32); return ret; } static const char * const ad5791_powerdown_modes[] = { "6kohm_to_gnd", "three_state", }; static int ad5791_get_powerdown_mode(struct iio_dev *indio_dev, const struct iio_chan_spec *chan) { struct ad5791_state *st = iio_priv(indio_dev); return st->pwr_down_mode; } static int ad5791_set_powerdown_mode(struct iio_dev *indio_dev, const struct iio_chan_spec *chan, unsigned int mode) { struct ad5791_state *st = iio_priv(indio_dev); st->pwr_down_mode = mode; return 0; } static const struct iio_enum ad5791_powerdown_mode_enum = { .items = ad5791_powerdown_modes, .num_items = ARRAY_SIZE(ad5791_powerdown_modes), .get = ad5791_get_powerdown_mode, .set = ad5791_set_powerdown_mode, }; static ssize_t ad5791_read_dac_powerdown(struct iio_dev *indio_dev, uintptr_t private, const struct iio_chan_spec *chan, char *buf) { struct ad5791_state *st = iio_priv(indio_dev); return sprintf(buf, "%d\n", st->pwr_down); } static ssize_t ad5791_write_dac_powerdown(struct iio_dev *indio_dev, uintptr_t private, const struct iio_chan_spec *chan, const char *buf, size_t len) { bool pwr_down; int ret; struct ad5791_state *st = iio_priv(indio_dev); ret = strtobool(buf, &pwr_down); if (ret) return ret; if (!pwr_down) { st->ctrl &= ~(AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI); } else { if (st->pwr_down_mode == AD5791_DAC_PWRDN_6K) st->ctrl |= AD5791_CTRL_OPGND; else if (st->pwr_down_mode == AD5791_DAC_PWRDN_3STATE) st->ctrl |= AD5791_CTRL_DACTRI; } st->pwr_down = pwr_down; ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl); return ret ? ret : len; } static int ad5791_get_lin_comp(unsigned int span) { if (span <= 10000) return AD5791_LINCOMP_0_10; else if (span <= 12000) return AD5791_LINCOMP_10_12; else if (span <= 16000) return AD5791_LINCOMP_12_16; else if (span <= 19000) return AD5791_LINCOMP_16_19; else return AD5791_LINCOMP_19_20; } static int ad5780_get_lin_comp(unsigned int span) { if (span <= 10000) return AD5780_LINCOMP_0_10; else return AD5780_LINCOMP_10_20; } static const struct ad5791_chip_info ad5791_chip_info_tbl[] = { [ID_AD5760] = { .get_lin_comp = ad5780_get_lin_comp, }, [ID_AD5780] = { .get_lin_comp = ad5780_get_lin_comp, }, [ID_AD5781] = { .get_lin_comp = ad5791_get_lin_comp, }, [ID_AD5791] = { .get_lin_comp = ad5791_get_lin_comp, }, }; static int ad5791_read_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int *val, int *val2, long m) { struct ad5791_state *st = iio_priv(indio_dev); u64 val64; int ret; switch (m) { case IIO_CHAN_INFO_RAW: ret = ad5791_spi_read(st, chan->address, val); if (ret) return ret; *val &= AD5791_DAC_MASK; *val >>= chan->scan_type.shift; return IIO_VAL_INT; case IIO_CHAN_INFO_SCALE: *val = st->vref_mv; *val2 = (1 << chan->scan_type.realbits) - 1; return IIO_VAL_FRACTIONAL; case IIO_CHAN_INFO_OFFSET: val64 = (((u64)st->vref_neg_mv) << chan->scan_type.realbits); do_div(val64, st->vref_mv); *val = -val64; return IIO_VAL_INT; default: return -EINVAL; } }; static const struct iio_chan_spec_ext_info ad5791_ext_info[] = { { .name = "powerdown", .shared = IIO_SHARED_BY_TYPE, .read = ad5791_read_dac_powerdown, .write = ad5791_write_dac_powerdown, }, IIO_ENUM("powerdown_mode", IIO_SHARED_BY_TYPE, &ad5791_powerdown_mode_enum), IIO_ENUM_AVAILABLE("powerdown_mode", &ad5791_powerdown_mode_enum), { }, }; #define AD5791_CHAN(bits, _shift) { \ .type = IIO_VOLTAGE, \ .output = 1, \ .indexed = 1, \ .address = AD5791_ADDR_DAC0, \ .channel = 0, \ .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \ .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) | \ BIT(IIO_CHAN_INFO_OFFSET), \ .scan_type = { \ .sign = 'u', \ .realbits = (bits), \ .storagebits = 24, \ .shift = (_shift), \ }, \ .ext_info = ad5791_ext_info, \ } static const struct iio_chan_spec ad5791_channels[] = { [ID_AD5760] = AD5791_CHAN(16, 4), [ID_AD5780] = AD5791_CHAN(18, 2), [ID_AD5781] = AD5791_CHAN(18, 2), [ID_AD5791] = AD5791_CHAN(20, 0) }; static int ad5791_write_raw(struct iio_dev *indio_dev, struct iio_chan_spec const *chan, int val, int val2, long mask) { struct ad5791_state *st = iio_priv(indio_dev); switch (mask) { case IIO_CHAN_INFO_RAW: val &= GENMASK(chan->scan_type.realbits - 1, 0); val <<= chan->scan_type.shift; return ad5791_spi_write(st, chan->address, val); default: return -EINVAL; } } static const struct iio_info ad5791_info = { .read_raw = &ad5791_read_raw, .write_raw = &ad5791_write_raw, }; static int ad5791_probe(struct spi_device *spi) { struct ad5791_platform_data *pdata = spi->dev.platform_data; struct iio_dev *indio_dev; struct ad5791_state *st; int ret, pos_voltage_uv = 0, neg_voltage_uv = 0; indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st)); if (!indio_dev) return -ENOMEM; st = iio_priv(indio_dev); st->reg_vdd = devm_regulator_get(&spi->dev, "vdd"); if (!IS_ERR(st->reg_vdd)) { ret = regulator_enable(st->reg_vdd); if (ret) return ret; ret = regulator_get_voltage(st->reg_vdd); if (ret < 0) goto error_disable_reg_pos; pos_voltage_uv = ret; } st->reg_vss = devm_regulator_get(&spi->dev, "vss"); if (!IS_ERR(st->reg_vss)) { ret = regulator_enable(st->reg_vss); if (ret) goto error_disable_reg_pos; ret = regulator_get_voltage(st->reg_vss); if (ret < 0) goto error_disable_reg_neg; neg_voltage_uv = ret; } st->pwr_down = true; st->spi = spi; if (!IS_ERR(st->reg_vss) && !IS_ERR(st->reg_vdd)) { st->vref_mv = (pos_voltage_uv + neg_voltage_uv) / 1000; st->vref_neg_mv = neg_voltage_uv / 1000; } else if (pdata) { st->vref_mv = pdata->vref_pos_mv + pdata->vref_neg_mv; st->vref_neg_mv = pdata->vref_neg_mv; } else { dev_warn(&spi->dev, "reference voltage unspecified\n"); } ret = ad5791_spi_write(st, AD5791_ADDR_SW_CTRL, AD5791_SWCTRL_RESET); if (ret) goto error_disable_reg_neg; st->chip_info = &ad5791_chip_info_tbl[spi_get_device_id(spi) ->driver_data]; st->ctrl = AD5761_CTRL_LINCOMP(st->chip_info->get_lin_comp(st->vref_mv)) | ((pdata && pdata->use_rbuf_gain2) ? 0 : AD5791_CTRL_RBUF) | AD5791_CTRL_BIN2SC; ret = ad5791_spi_write(st, AD5791_ADDR_CTRL, st->ctrl | AD5791_CTRL_OPGND | AD5791_CTRL_DACTRI); if (ret) goto error_disable_reg_neg; spi_set_drvdata(spi, indio_dev); indio_dev->dev.parent = &spi->dev; indio_dev->info = &ad5791_info; indio_dev->modes = INDIO_DIRECT_MODE; indio_dev->channels = &ad5791_channels[spi_get_device_id(spi)->driver_data]; indio_dev->num_channels = 1; indio_dev->name = spi_get_device_id(st->spi)->name; ret = iio_device_register(indio_dev); if (ret) goto error_disable_reg_neg; return 0; error_disable_reg_neg: if (!IS_ERR(st->reg_vss)) regulator_disable(st->reg_vss); error_disable_reg_pos: if (!IS_ERR(st->reg_vdd)) regulator_disable(st->reg_vdd); return ret; } static int ad5791_remove(struct spi_device *spi) { struct iio_dev *indio_dev = spi_get_drvdata(spi); struct ad5791_state *st = iio_priv(indio_dev); iio_device_unregister(indio_dev); if (!IS_ERR(st->reg_vdd)) regulator_disable(st->reg_vdd); if (!IS_ERR(st->reg_vss)) regulator_disable(st->reg_vss); return 0; } static const struct spi_device_id ad5791_id[] = { {"ad5760", ID_AD5760}, {"ad5780", ID_AD5780}, {"ad5781", ID_AD5781}, {"ad5790", ID_AD5791}, {"ad5791", ID_AD5791}, {} }; MODULE_DEVICE_TABLE(spi, ad5791_id); static struct spi_driver ad5791_driver = { .driver = { .name = "ad5791", }, .probe = ad5791_probe, .remove = ad5791_remove, .id_table = ad5791_id, }; module_spi_driver(ad5791_driver); MODULE_AUTHOR("Michael Hennerich <michael.hennerich@analog.com>"); MODULE_DESCRIPTION("Analog Devices AD5760/AD5780/AD5781/AD5790/AD5791 DAC"); MODULE_LICENSE("GPL v2");