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/*
* AD5686R, AD5685R, AD5684R Digital to analog converters driver
*
* Copyright 2011 Analog Devices Inc.
*
* Licensed under the GPL-2.
*/
#include <linux/interrupt.h>
#include <linux/fs.h>
#include <linux/device.h>
#include <linux/module.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/iio/iio.h>
#include <linux/iio/sysfs.h>
#define AD5686_DAC_CHANNELS 4
#define AD5686_ADDR(x) ((x) << 16)
#define AD5686_CMD(x) ((x) << 20)
#define AD5686_ADDR_DAC(chan) (0x1 << (chan))
#define AD5686_ADDR_ALL_DAC 0xF
#define AD5686_CMD_NOOP 0x0
#define AD5686_CMD_WRITE_INPUT_N 0x1
#define AD5686_CMD_UPDATE_DAC_N 0x2
#define AD5686_CMD_WRITE_INPUT_N_UPDATE_N 0x3
#define AD5686_CMD_POWERDOWN_DAC 0x4
#define AD5686_CMD_LDAC_MASK 0x5
#define AD5686_CMD_RESET 0x6
#define AD5686_CMD_INTERNAL_REFER_SETUP 0x7
#define AD5686_CMD_DAISY_CHAIN_ENABLE 0x8
#define AD5686_CMD_READBACK_ENABLE 0x9
#define AD5686_LDAC_PWRDN_NONE 0x0
#define AD5686_LDAC_PWRDN_1K 0x1
#define AD5686_LDAC_PWRDN_100K 0x2
#define AD5686_LDAC_PWRDN_3STATE 0x3
/**
* struct ad5686_chip_info - chip specific information
* @int_vref_mv: AD5620/40/60: the internal reference voltage
* @channel: channel specification
*/
struct ad5686_chip_info {
u16 int_vref_mv;
struct iio_chan_spec channel[AD5686_DAC_CHANNELS];
};
/**
* struct ad5446_state - driver instance specific data
* @spi: spi_device
* @chip_info: chip model specific constants, available modes etc
* @reg: supply regulator
* @vref_mv: actual reference voltage used
* @pwr_down_mask: power down mask
* @pwr_down_mode: current power down mode
* @data: spi transfer buffers
*/
struct ad5686_state {
struct spi_device *spi;
const struct ad5686_chip_info *chip_info;
struct regulator *reg;
unsigned short vref_mv;
unsigned pwr_down_mask;
unsigned pwr_down_mode;
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
*/
union {
u32 d32;
u8 d8[4];
} data[3] ____cacheline_aligned;
};
/**
* ad5686_supported_device_ids:
*/
enum ad5686_supported_device_ids {
ID_AD5684,
ID_AD5685,
ID_AD5686,
};
static int ad5686_spi_write(struct ad5686_state *st,
u8 cmd, u8 addr, u16 val, u8 shift)
{
val <<= shift;
st->data[0].d32 = cpu_to_be32(AD5686_CMD(cmd) |
AD5686_ADDR(addr) |
val);
return spi_write(st->spi, &st->data[0].d8[1], 3);
}
static int ad5686_spi_read(struct ad5686_state *st, u8 addr)
{
struct spi_transfer t[] = {
{
.tx_buf = &st->data[0].d8[1],
.len = 3,
.cs_change = 1,
}, {
.tx_buf = &st->data[1].d8[1],
.rx_buf = &st->data[2].d8[1],
.len = 3,
},
};
struct spi_message m;
int ret;
spi_message_init(&m);
spi_message_add_tail(&t[0], &m);
spi_message_add_tail(&t[1], &m);
st->data[0].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_READBACK_ENABLE) |
AD5686_ADDR(addr));
st->data[1].d32 = cpu_to_be32(AD5686_CMD(AD5686_CMD_NOOP));
ret = spi_sync(st->spi, &m);
if (ret < 0)
return ret;
return be32_to_cpu(st->data[2].d32);
}
static const char * const ad5686_powerdown_modes[] = {
"1kohm_to_gnd",
"100kohm_to_gnd",
"three_state"
};
static int ad5686_get_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct ad5686_state *st = iio_priv(indio_dev);
return ((st->pwr_down_mode >> (chan->channel * 2)) & 0x3) - 1;
}
static int ad5686_set_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, unsigned int mode)
{
struct ad5686_state *st = iio_priv(indio_dev);
st->pwr_down_mode &= ~(0x3 << (chan->channel * 2));
st->pwr_down_mode |= ((mode + 1) << (chan->channel * 2));
return 0;
}
static const struct iio_enum ad5686_powerdown_mode_enum = {
.items = ad5686_powerdown_modes,
.num_items = ARRAY_SIZE(ad5686_powerdown_modes),
.get = ad5686_get_powerdown_mode,
.set = ad5686_set_powerdown_mode,
};
static ssize_t ad5686_read_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan, char *buf)
{
struct ad5686_state *st = iio_priv(indio_dev);
return sprintf(buf, "%d\n", !!(st->pwr_down_mask &
(0x3 << (chan->channel * 2))));
}
static ssize_t ad5686_write_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
size_t len)
{
bool readin;
int ret;
struct ad5686_state *st = iio_priv(indio_dev);
ret = strtobool(buf, &readin);
if (ret)
return ret;
if (readin)
st->pwr_down_mask |= (0x3 << (chan->channel * 2));
else
st->pwr_down_mask &= ~(0x3 << (chan->channel * 2));
ret = ad5686_spi_write(st, AD5686_CMD_POWERDOWN_DAC, 0,
st->pwr_down_mask & st->pwr_down_mode, 0);
return ret ? ret : len;
}
static int ad5686_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct ad5686_state *st = iio_priv(indio_dev);
unsigned long scale_uv;
int ret;
switch (m) {
case IIO_CHAN_INFO_RAW:
mutex_lock(&indio_dev->mlock);
ret = ad5686_spi_read(st, chan->address);
mutex_unlock(&indio_dev->mlock);
if (ret < 0)
return ret;
*val = ret;
return IIO_VAL_INT;
break;
case IIO_CHAN_INFO_SCALE:
scale_uv = (st->vref_mv * 100000)
>> (chan->scan_type.realbits);
*val = scale_uv / 100000;
*val2 = (scale_uv % 100000) * 10;
return IIO_VAL_INT_PLUS_MICRO;
}
return -EINVAL;
}
static int ad5686_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int val,
int val2,
long mask)
{
struct ad5686_state *st = iio_priv(indio_dev);
int ret;
switch (mask) {
case IIO_CHAN_INFO_RAW:
if (val > (1 << chan->scan_type.realbits) || val < 0)
return -EINVAL;
mutex_lock(&indio_dev->mlock);
ret = ad5686_spi_write(st,
AD5686_CMD_WRITE_INPUT_N_UPDATE_N,
chan->address,
val,
chan->scan_type.shift);
mutex_unlock(&indio_dev->mlock);
break;
default:
ret = -EINVAL;
}
return ret;
}
static const struct iio_info ad5686_info = {
.read_raw = ad5686_read_raw,
.write_raw = ad5686_write_raw,
.driver_module = THIS_MODULE,
};
static const struct iio_chan_spec_ext_info ad5686_ext_info[] = {
{
.name = "powerdown",
.read = ad5686_read_dac_powerdown,
.write = ad5686_write_dac_powerdown,
},
IIO_ENUM("powerdown_mode", false, &ad5686_powerdown_mode_enum),
IIO_ENUM_AVAILABLE("powerdown_mode", &ad5686_powerdown_mode_enum),
{ },
};
#define AD5868_CHANNEL(chan, bits, shift) { \
.type
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