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/*
* 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/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/dac/ad5791.h>
#define AD5791_RES_MASK(x) ((1 << (x)) - 1)
#define AD5791_DAC_MASK AD5791_RES_MASK(20)
#define AD5791_DAC_MSB (1 << 19)
#define AD5791_CMD_READ (1 << 23)
#define AD5791_CMD_WRITE (0 << 23)
#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 (1 << 1)
#define AD5791_CTRL_OPGND (1 << 2)
#define AD5791_CTRL_DACTRI (1 << 3)
#define AD5791_CTRL_BIN2SC (1 << 4)
#define AD5791_CTRL_SDODIS (1 << 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 (1 << 0)
#define AD5791_SWCTRL_CLR (1 << 1)
#define AD5791_SWCTRL_RESET (1 << 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
* @us: 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;
};
/**
* ad5791_supported_device_ids:
*/
enum ad5791_supported_device_ids {
ID_AD5760,
ID_AD5780,
ID_AD5781,
ID_AD5791,
};
static int ad5791_spi_write(struct spi_device *spi, u8 addr, u32 val)
{
union {
u32 d32;
u8 d8[4];
} data;
data.d32 = cpu_to_be32(AD5791_CMD_WRITE |
AD5791_ADDR(addr) |
(val & AD5791_DAC_MASK));
return spi_write(spi, &data.d8[1], 3);
}
static int ad5791_spi_read(struct spi_device *spi, u8 addr, u32 *val)
{
union {
u32 d32;
u8 d8[4];
} data[3];
int ret;
struct spi_transfer xfers[] = {
{
.tx_buf = &data[0].d8[1],
.bits_per_word = 8,
.len = 3,
.cs_change = 1,
}, {
.tx_buf = &data[1].d8[1],
.rx_buf = &data[2].d8[1],
.bits_per_word = 8,
.len = 3,
},
};
data[0].d32 = cpu_to_be32(AD5791_CMD_READ |
AD5791_ADDR(addr));
data[1].d32 = cpu_to_be32(AD5791_ADDR(AD5791_ADDR_NOOP));
ret = spi_sync_transfer(spi, xfers, ARRAY_SIZE(xfers));
*val = be32_to_cpu(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->spi, 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->spi, 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,
.wri
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