linux/drivers/iio/dac/ad5064.c
Lars-Peter Clausen 25682ae5e4 iio:ad5064: Report scale as fractional value
Move the complexity of calculating the fixed point scale to the core.

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
2013-10-01 16:19:08 +01:00

680 lines
16 KiB
C

/*
* AD5024, AD5025, AD5044, AD5045, AD5064, AD5064-1, AD5065, AD5628, AD5629R,
* AD5648, AD5666, AD5668, AD5669R Digital to analog converters driver
*
* Copyright 2011 Analog Devices Inc.
*
* Licensed under the GPL-2.
*/
#include <linux/device.h>
#include <linux/err.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/i2c.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/regulator/consumer.h>
#include <asm/unaligned.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#define AD5064_MAX_DAC_CHANNELS 8
#define AD5064_MAX_VREFS 4
#define AD5064_ADDR(x) ((x) << 20)
#define AD5064_CMD(x) ((x) << 24)
#define AD5064_ADDR_ALL_DAC 0xF
#define AD5064_CMD_WRITE_INPUT_N 0x0
#define AD5064_CMD_UPDATE_DAC_N 0x1
#define AD5064_CMD_WRITE_INPUT_N_UPDATE_ALL 0x2
#define AD5064_CMD_WRITE_INPUT_N_UPDATE_N 0x3
#define AD5064_CMD_POWERDOWN_DAC 0x4
#define AD5064_CMD_CLEAR 0x5
#define AD5064_CMD_LDAC_MASK 0x6
#define AD5064_CMD_RESET 0x7
#define AD5064_CMD_CONFIG 0x8
#define AD5064_CONFIG_DAISY_CHAIN_ENABLE BIT(1)
#define AD5064_CONFIG_INT_VREF_ENABLE BIT(0)
#define AD5064_LDAC_PWRDN_NONE 0x0
#define AD5064_LDAC_PWRDN_1K 0x1
#define AD5064_LDAC_PWRDN_100K 0x2
#define AD5064_LDAC_PWRDN_3STATE 0x3
/**
* struct ad5064_chip_info - chip specific information
* @shared_vref: whether the vref supply is shared between channels
* @internal_vref: internal reference voltage. 0 if the chip has no internal
* vref.
* @channel: channel specification
* @num_channels: number of channels
*/
struct ad5064_chip_info {
bool shared_vref;
unsigned long internal_vref;
const struct iio_chan_spec *channels;
unsigned int num_channels;
};
struct ad5064_state;
typedef int (*ad5064_write_func)(struct ad5064_state *st, unsigned int cmd,
unsigned int addr, unsigned int val);
/**
* struct ad5064_state - driver instance specific data
* @dev: the device for this driver instance
* @chip_info: chip model specific constants, available modes etc
* @vref_reg: vref supply regulators
* @pwr_down: whether channel is powered down
* @pwr_down_mode: channel's current power down mode
* @dac_cache: current DAC raw value (chip does not support readback)
* @use_internal_vref: set to true if the internal reference voltage should be
* used.
* @write: register write callback
* @data: i2c/spi transfer buffers
*/
struct ad5064_state {
struct device *dev;
const struct ad5064_chip_info *chip_info;
struct regulator_bulk_data vref_reg[AD5064_MAX_VREFS];
bool pwr_down[AD5064_MAX_DAC_CHANNELS];
u8 pwr_down_mode[AD5064_MAX_DAC_CHANNELS];
unsigned int dac_cache[AD5064_MAX_DAC_CHANNELS];
bool use_internal_vref;
ad5064_write_func write;
/*
* DMA (thus cache coherency maintenance) requires the
* transfer buffers to live in their own cache lines.
*/
union {
u8 i2c[3];
__be32 spi;
} data ____cacheline_aligned;
};
enum ad5064_type {
ID_AD5024,
ID_AD5025,
ID_AD5044,
ID_AD5045,
ID_AD5064,
ID_AD5064_1,
ID_AD5065,
ID_AD5628_1,
ID_AD5628_2,
ID_AD5648_1,
ID_AD5648_2,
ID_AD5666_1,
ID_AD5666_2,
ID_AD5668_1,
ID_AD5668_2,
};
static int ad5064_write(struct ad5064_state *st, unsigned int cmd,
unsigned int addr, unsigned int val, unsigned int shift)
{
val <<= shift;
return st->write(st, cmd, addr, val);
}
static int ad5064_sync_powerdown_mode(struct ad5064_state *st,
const struct iio_chan_spec *chan)
{
unsigned int val;
int ret;
val = (0x1 << chan->address);
if (st->pwr_down[chan->channel])
val |= st->pwr_down_mode[chan->channel] << 8;
ret = ad5064_write(st, AD5064_CMD_POWERDOWN_DAC, 0, val, 0);
return ret;
}
static const char * const ad5064_powerdown_modes[] = {
"1kohm_to_gnd",
"100kohm_to_gnd",
"three_state",
};
static int ad5064_get_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan)
{
struct ad5064_state *st = iio_priv(indio_dev);
return st->pwr_down_mode[chan->channel] - 1;
}
static int ad5064_set_powerdown_mode(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, unsigned int mode)
{
struct ad5064_state *st = iio_priv(indio_dev);
int ret;
mutex_lock(&indio_dev->mlock);
st->pwr_down_mode[chan->channel] = mode + 1;
ret = ad5064_sync_powerdown_mode(st, chan);
mutex_unlock(&indio_dev->mlock);
return ret;
}
static const struct iio_enum ad5064_powerdown_mode_enum = {
.items = ad5064_powerdown_modes,
.num_items = ARRAY_SIZE(ad5064_powerdown_modes),
.get = ad5064_get_powerdown_mode,
.set = ad5064_set_powerdown_mode,
};
static ssize_t ad5064_read_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan, char *buf)
{
struct ad5064_state *st = iio_priv(indio_dev);
return sprintf(buf, "%d\n", st->pwr_down[chan->channel]);
}
static ssize_t ad5064_write_dac_powerdown(struct iio_dev *indio_dev,
uintptr_t private, const struct iio_chan_spec *chan, const char *buf,
size_t len)
{
struct ad5064_state *st = iio_priv(indio_dev);
bool pwr_down;
int ret;
ret = strtobool(buf, &pwr_down);
if (ret)
return ret;
mutex_lock(&indio_dev->mlock);
st->pwr_down[chan->channel] = pwr_down;
ret = ad5064_sync_powerdown_mode(st, chan);
mutex_unlock(&indio_dev->mlock);
return ret ? ret : len;
}
static int ad5064_get_vref(struct ad5064_state *st,
struct iio_chan_spec const *chan)
{
unsigned int i;
if (st->use_internal_vref)
return st->chip_info->internal_vref;
i = st->chip_info->shared_vref ? 0 : chan->channel;
return regulator_get_voltage(st->vref_reg[i].consumer);
}
static int ad5064_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct ad5064_state *st = iio_priv(indio_dev);
int scale_uv;
switch (m) {
case IIO_CHAN_INFO_RAW:
*val = st->dac_cache[chan->channel];
return IIO_VAL_INT;
case IIO_CHAN_INFO_SCALE:
scale_uv = ad5064_get_vref(st, chan);
if (scale_uv < 0)
return scale_uv;
*val = scale_uv / 1000;
*val2 = chan->scan_type.realbits;
return IIO_VAL_FRACTIONAL_LOG2;
default:
break;
}
return -EINVAL;
}
static int ad5064_write_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan, int val, int val2, long mask)
{
struct ad5064_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 = ad5064_write(st, AD5064_CMD_WRITE_INPUT_N_UPDATE_N,
chan->address, val, chan->scan_type.shift);
if (ret == 0)
st->dac_cache[chan->channel] = val;
mutex_unlock(&indio_dev->mlock);
break;
default:
ret = -EINVAL;
}
return ret;
}
static const struct iio_info ad5064_info = {
.read_raw = ad5064_read_raw,
.write_raw = ad5064_write_raw,
.driver_module = THIS_MODULE,
};
static const struct iio_chan_spec_ext_info ad5064_ext_info[] = {
{
.name = "powerdown",
.read = ad5064_read_dac_powerdown,
.write = ad5064_write_dac_powerdown,
.shared = IIO_SEPARATE,
},
IIO_ENUM("powerdown_mode", IIO_SEPARATE, &ad5064_powerdown_mode_enum),
IIO_ENUM_AVAILABLE("powerdown_mode", &ad5064_powerdown_mode_enum),
{ },
};
#define AD5064_CHANNEL(chan, addr, bits) { \
.type = IIO_VOLTAGE, \
.indexed = 1, \
.output = 1, \
.channel = (chan), \
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW) | \
BIT(IIO_CHAN_INFO_SCALE), \
.address = addr, \
.scan_type = IIO_ST('u', (bits), 16, 20 - (bits)), \
.ext_info = ad5064_ext_info, \
}
#define DECLARE_AD5064_CHANNELS(name, bits) \
const struct iio_chan_spec name[] = { \
AD5064_CHANNEL(0, 0, bits), \
AD5064_CHANNEL(1, 1, bits), \
AD5064_CHANNEL(2, 2, bits), \
AD5064_CHANNEL(3, 3, bits), \
AD5064_CHANNEL(4, 4, bits), \
AD5064_CHANNEL(5, 5, bits), \
AD5064_CHANNEL(6, 6, bits), \
AD5064_CHANNEL(7, 7, bits), \
}
#define DECLARE_AD5065_CHANNELS(name, bits) \
const struct iio_chan_spec name[] = { \
AD5064_CHANNEL(0, 0, bits), \
AD5064_CHANNEL(1, 3, bits), \
}
static DECLARE_AD5064_CHANNELS(ad5024_channels, 12);
static DECLARE_AD5064_CHANNELS(ad5044_channels, 14);
static DECLARE_AD5064_CHANNELS(ad5064_channels, 16);
static DECLARE_AD5065_CHANNELS(ad5025_channels, 12);
static DECLARE_AD5065_CHANNELS(ad5045_channels, 14);
static DECLARE_AD5065_CHANNELS(ad5065_channels, 16);
static const struct ad5064_chip_info ad5064_chip_info_tbl[] = {
[ID_AD5024] = {
.shared_vref = false,
.channels = ad5024_channels,
.num_channels = 4,
},
[ID_AD5025] = {
.shared_vref = false,
.channels = ad5025_channels,
.num_channels = 2,
},
[ID_AD5044] = {
.shared_vref = false,
.channels = ad5044_channels,
.num_channels = 4,
},
[ID_AD5045] = {
.shared_vref = false,
.channels = ad5045_channels,
.num_channels = 2,
},
[ID_AD5064] = {
.shared_vref = false,
.channels = ad5064_channels,
.num_channels = 4,
},
[ID_AD5064_1] = {
.shared_vref = true,
.channels = ad5064_channels,
.num_channels = 4,
},
[ID_AD5065] = {
.shared_vref = false,
.channels = ad5065_channels,
.num_channels = 2,
},
[ID_AD5628_1] = {
.shared_vref = true,
.internal_vref = 2500000,
.channels = ad5024_channels,
.num_channels = 8,
},
[ID_AD5628_2] = {
.shared_vref = true,
.internal_vref = 5000000,
.channels = ad5024_channels,
.num_channels = 8,
},
[ID_AD5648_1] = {
.shared_vref = true,
.internal_vref = 2500000,
.channels = ad5044_channels,
.num_channels = 8,
},
[ID_AD5648_2] = {
.shared_vref = true,
.internal_vref = 5000000,
.channels = ad5044_channels,
.num_channels = 8,
},
[ID_AD5666_1] = {
.shared_vref = true,
.internal_vref = 2500000,
.channels = ad5064_channels,
.num_channels = 4,
},
[ID_AD5666_2] = {
.shared_vref = true,
.internal_vref = 5000000,
.channels = ad5064_channels,
.num_channels = 4,
},
[ID_AD5668_1] = {
.shared_vref = true,
.internal_vref = 2500000,
.channels = ad5064_channels,
.num_channels = 8,
},
[ID_AD5668_2] = {
.shared_vref = true,
.internal_vref = 5000000,
.channels = ad5064_channels,
.num_channels = 8,
},
};
static inline unsigned int ad5064_num_vref(struct ad5064_state *st)
{
return st->chip_info->shared_vref ? 1 : st->chip_info->num_channels;
}
static const char * const ad5064_vref_names[] = {
"vrefA",
"vrefB",
"vrefC",
"vrefD",
};
static const char * const ad5064_vref_name(struct ad5064_state *st,
unsigned int vref)
{
return st->chip_info->shared_vref ? "vref" : ad5064_vref_names[vref];
}
static int ad5064_probe(struct device *dev, enum ad5064_type type,
const char *name, ad5064_write_func write)
{
struct iio_dev *indio_dev;
struct ad5064_state *st;
unsigned int midscale;
unsigned int i;
int ret;
indio_dev = devm_iio_device_alloc(dev, sizeof(*st));
if (indio_dev == NULL)
return -ENOMEM;
st = iio_priv(indio_dev);
dev_set_drvdata(dev, indio_dev);
st->chip_info = &ad5064_chip_info_tbl[type];
st->dev = dev;
st->write = write;
for (i = 0; i < ad5064_num_vref(st); ++i)
st->vref_reg[i].supply = ad5064_vref_name(st, i);
ret = devm_regulator_bulk_get(dev, ad5064_num_vref(st),
st->vref_reg);
if (ret) {
if (!st->chip_info->internal_vref)
return ret;
st->use_internal_vref = true;
ret = ad5064_write(st, AD5064_CMD_CONFIG, 0,
AD5064_CONFIG_INT_VREF_ENABLE, 0);
if (ret) {
dev_err(dev, "Failed to enable internal vref: %d\n",
ret);
return ret;
}
} else {
ret = regulator_bulk_enable(ad5064_num_vref(st), st->vref_reg);
if (ret)
return ret;
}
indio_dev->dev.parent = dev;
indio_dev->name = name;
indio_dev->info = &ad5064_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = st->chip_info->channels;
indio_dev->num_channels = st->chip_info->num_channels;
midscale = (1 << indio_dev->channels[0].scan_type.realbits) / 2;
for (i = 0; i < st->chip_info->num_channels; ++i) {
st->pwr_down_mode[i] = AD5064_LDAC_PWRDN_1K;
st->dac_cache[i] = midscale;
}
ret = iio_device_register(indio_dev);
if (ret)
goto error_disable_reg;
return 0;
error_disable_reg:
if (!st->use_internal_vref)
regulator_bulk_disable(ad5064_num_vref(st), st->vref_reg);
return ret;
}
static int ad5064_remove(struct device *dev)
{
struct iio_dev *indio_dev = dev_get_drvdata(dev);
struct ad5064_state *st = iio_priv(indio_dev);
iio_device_unregister(indio_dev);
if (!st->use_internal_vref)
regulator_bulk_disable(ad5064_num_vref(st), st->vref_reg);
return 0;
}
#if IS_ENABLED(CONFIG_SPI_MASTER)
static int ad5064_spi_write(struct ad5064_state *st, unsigned int cmd,
unsigned int addr, unsigned int val)
{
struct spi_device *spi = to_spi_device(st->dev);
st->data.spi = cpu_to_be32(AD5064_CMD(cmd) | AD5064_ADDR(addr) | val);
return spi_write(spi, &st->data.spi, sizeof(st->data.spi));
}
static int ad5064_spi_probe(struct spi_device *spi)
{
const struct spi_device_id *id = spi_get_device_id(spi);
return ad5064_probe(&spi->dev, id->driver_data, id->name,
ad5064_spi_write);
}
static int ad5064_spi_remove(struct spi_device *spi)
{
return ad5064_remove(&spi->dev);
}
static const struct spi_device_id ad5064_spi_ids[] = {
{"ad5024", ID_AD5024},
{"ad5025", ID_AD5025},
{"ad5044", ID_AD5044},
{"ad5045", ID_AD5045},
{"ad5064", ID_AD5064},
{"ad5064-1", ID_AD5064_1},
{"ad5065", ID_AD5065},
{"ad5628-1", ID_AD5628_1},
{"ad5628-2", ID_AD5628_2},
{"ad5648-1", ID_AD5648_1},
{"ad5648-2", ID_AD5648_2},
{"ad5666-1", ID_AD5666_1},
{"ad5666-2", ID_AD5666_2},
{"ad5668-1", ID_AD5668_1},
{"ad5668-2", ID_AD5668_2},
{"ad5668-3", ID_AD5668_2}, /* similar enough to ad5668-2 */
{}
};
MODULE_DEVICE_TABLE(spi, ad5064_spi_ids);
static struct spi_driver ad5064_spi_driver = {
.driver = {
.name = "ad5064",
.owner = THIS_MODULE,
},
.probe = ad5064_spi_probe,
.remove = ad5064_spi_remove,
.id_table = ad5064_spi_ids,
};
static int __init ad5064_spi_register_driver(void)
{
return spi_register_driver(&ad5064_spi_driver);
}
static void ad5064_spi_unregister_driver(void)
{
spi_unregister_driver(&ad5064_spi_driver);
}
#else
static inline int ad5064_spi_register_driver(void) { return 0; }
static inline void ad5064_spi_unregister_driver(void) { }
#endif
#if IS_ENABLED(CONFIG_I2C)
static int ad5064_i2c_write(struct ad5064_state *st, unsigned int cmd,
unsigned int addr, unsigned int val)
{
struct i2c_client *i2c = to_i2c_client(st->dev);
st->data.i2c[0] = (cmd << 4) | addr;
put_unaligned_be16(val, &st->data.i2c[1]);
return i2c_master_send(i2c, st->data.i2c, 3);
}
static int ad5064_i2c_probe(struct i2c_client *i2c,
const struct i2c_device_id *id)
{
return ad5064_probe(&i2c->dev, id->driver_data, id->name,
ad5064_i2c_write);
}
static int ad5064_i2c_remove(struct i2c_client *i2c)
{
return ad5064_remove(&i2c->dev);
}
static const struct i2c_device_id ad5064_i2c_ids[] = {
{"ad5629-1", ID_AD5628_1},
{"ad5629-2", ID_AD5628_2},
{"ad5629-3", ID_AD5628_2}, /* similar enough to ad5629-2 */
{"ad5669-1", ID_AD5668_1},
{"ad5669-2", ID_AD5668_2},
{"ad5669-3", ID_AD5668_2}, /* similar enough to ad5669-2 */
{}
};
MODULE_DEVICE_TABLE(i2c, ad5064_i2c_ids);
static struct i2c_driver ad5064_i2c_driver = {
.driver = {
.name = "ad5064",
.owner = THIS_MODULE,
},
.probe = ad5064_i2c_probe,
.remove = ad5064_i2c_remove,
.id_table = ad5064_i2c_ids,
};
static int __init ad5064_i2c_register_driver(void)
{
return i2c_add_driver(&ad5064_i2c_driver);
}
static void __exit ad5064_i2c_unregister_driver(void)
{
i2c_del_driver(&ad5064_i2c_driver);
}
#else
static inline int ad5064_i2c_register_driver(void) { return 0; }
static inline void ad5064_i2c_unregister_driver(void) { }
#endif
static int __init ad5064_init(void)
{
int ret;
ret = ad5064_spi_register_driver();
if (ret)
return ret;
ret = ad5064_i2c_register_driver();
if (ret) {
ad5064_spi_unregister_driver();
return ret;
}
return 0;
}
module_init(ad5064_init);
static void __exit ad5064_exit(void)
{
ad5064_i2c_unregister_driver();
ad5064_spi_unregister_driver();
}
module_exit(ad5064_exit);
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("Analog Devices AD5024 and similar multi-channel DACs");
MODULE_LICENSE("GPL v2");