#include <linux/types.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/of.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/delay.h>
#include <linux/gpio/consumer.h>
#include <linux/module.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#define DRV_NAME "ad2s1210"
#define AD2S1210_DEF_CONTROL 0x7E
#define AD2S1210_MSB_IS_HIGH 0x80
#define AD2S1210_MSB_IS_LOW 0x7F
#define AD2S1210_PHASE_LOCK_RANGE_44 0x20
#define AD2S1210_ENABLE_HYSTERESIS 0x10
#define AD2S1210_SET_ENRES1 0x08
#define AD2S1210_SET_ENRES0 0x04
#define AD2S1210_SET_RES1 0x02
#define AD2S1210_SET_RES0 0x01
#define AD2S1210_SET_RESOLUTION (AD2S1210_SET_RES1 | AD2S1210_SET_RES0)
#define AD2S1210_REG_POSITION 0x80
#define AD2S1210_REG_VELOCITY 0x82
#define AD2S1210_REG_LOS_THRD 0x88
#define AD2S1210_REG_DOS_OVR_THRD 0x89
#define AD2S1210_REG_DOS_MIS_THRD 0x8A
#define AD2S1210_REG_DOS_RST_MAX_THRD 0x8B
#define AD2S1210_REG_DOS_RST_MIN_THRD 0x8C
#define AD2S1210_REG_LOT_HIGH_THRD 0x8D
#define AD2S1210_REG_LOT_LOW_THRD 0x8E
#define AD2S1210_REG_EXCIT_FREQ 0x91
#define AD2S1210_REG_CONTROL 0x92
#define AD2S1210_REG_SOFT_RESET 0xF0
#define AD2S1210_REG_FAULT 0xFF
#define AD2S1210_MIN_CLKIN 6144000
#define AD2S1210_MAX_CLKIN 10240000
#define AD2S1210_MIN_EXCIT 2000
#define AD2S1210_MAX_EXCIT 20000
#define AD2S1210_MIN_FCW 0x4
#define AD2S1210_MAX_FCW 0x50
#define AD2S1210_DEF_EXCIT 10000
enum ad2s1210_mode {
MOD_POS = 0,
MOD_VEL,
MOD_CONFIG,
MOD_RESERVED,
};
enum ad2s1210_gpios {
AD2S1210_SAMPLE,
AD2S1210_A0,
AD2S1210_A1,
AD2S1210_RES0,
AD2S1210_RES1,
};
struct ad2s1210_gpio {
const char *name;
unsigned long flags;
};
static const struct ad2s1210_gpio gpios[] = {
[AD2S1210_SAMPLE] = { .name = "adi,sample", .flags = GPIOD_OUT_LOW },
[AD2S1210_A0] = { .name = "adi,a0", .flags = GPIOD_OUT_LOW },
[AD2S1210_A1] = { .name = "adi,a1", .flags = GPIOD_OUT_LOW },
[AD2S1210_RES0] = { .name = "adi,res0", .flags = GPIOD_OUT_LOW },
[AD2S1210_RES1] = { .name = "adi,res1", .flags = GPIOD_OUT_LOW },
};
static const unsigned int ad2s1210_resolution_value[] = { 10, 12, 14, 16 };
struct ad2s1210_state {
struct mutex lock;
struct spi_device *sdev;
struct gpio_desc *gpios[5];
unsigned int fclkin;
unsigned int fexcit;
bool hysteresis;
u8 resolution;
enum ad2s1210_mode mode;
u8 rx[2] __aligned(IIO_DMA_MINALIGN);
u8 tx[2];
};
static const int ad2s1210_mode_vals[4][2] = {
[MOD_POS] = { 0, 0 },
[MOD_VEL] = { 0, 1 },
[MOD_CONFIG] = { 1, 1 },
};
static inline void ad2s1210_set_mode(enum ad2s1210_mode mode,
struct ad2s1210_state *st)
{
gpiod_set_value(st->gpios[AD2S1210_A0], ad2s1210_mode_vals[mode][0]);
gpiod_set_value(st->gpios[AD2S1210_A1], ad2s1210_mode_vals[mode][1]);
st->mode = mode;
}
static int ad2s1210_config_write(struct ad2s1210_state *st, u8 data)
{
int ret;
ad2s1210_set_mode(MOD_CONFIG, st);
st->tx[0] = data;
ret = spi_write(st->sdev, st->tx, 1);
if (ret < 0)
return ret;
return 0;
}
static int ad2s1210_config_read(struct ad2s1210_state *st,
unsigned char address)
{
struct spi_transfer xfers[] = {
{
.len = 1,
.rx_buf = &st->rx[0],
.tx_buf = &st->tx[0],
.cs_change = 1,
}, {
.len = 1,
.rx_buf = &st->rx[1],
.tx_buf = &st->tx[1],
},
};
int ret = 0;
ad2s1210_set_mode(MOD_CONFIG, st);
st->tx[0] = address | AD2S1210_MSB_IS_HIGH;
st->tx[1] = AD2S1210_REG_FAULT;
ret = spi_sync_transfer(st->sdev, xfers, 2);
if (ret < 0)
return ret;
return st->rx[1];
}
static inline
int ad2s1210_update_frequency_control_word(struct ad2s1210_state *st)
{
int ret;
unsigned char fcw;
fcw = (unsigned char)(st->fexcit * (1 << 15) / st->fclkin);
if (fcw < AD2S1210_MIN_FCW || fcw > AD2S1210_MAX_FCW) {
dev_err(&st->sdev->dev, "ad2s1210: FCW out of range\n");
return -ERANGE;
}
ret = ad2s1210_config_write(st, AD2S1210_REG_EXCIT_FREQ);
if (ret < 0)
return ret;
return ad2s1210_config_write(st, fcw);
}
static const int ad2s1210_res_pins[4][2] = {
{ 0, 0 }, {0, 1}, {1, 0}, {1, 1}
};
static inline void ad2s1210_set_resolution_pin(struct ad2s1210_state *st)
{
gpiod_set_value(st->gpios[AD2S1210_RES0],
ad2s1210_res_pins[(st->resolution - 10) / 2][0]);
gpiod_set_value(st->gpios[AD2S1210_RES1],
ad2s1210_res_pins[(st->resolution - 10) / 2][1]);
}
static inline int ad2s1210_soft_reset(struct ad2s1210_state *st)
{
int ret;
ret = ad2s1210_config_write(st, AD2S1210_REG_SOFT_RESET);
if (ret < 0)
return ret;
return ad2s1210_config_write(st, 0x0);
}
static ssize_t ad2s1210_show_fclkin(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
return sprintf(buf, "%u\n", st->fclkin);
}
static ssize_t ad2s1210_store_fclkin(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
unsigned int fclkin;
int ret;
ret = kstrtouint(buf, 10, &fclkin);
if (ret)
return ret;
if (fclkin < AD2S1210_MIN_CLKIN || fclkin > AD2S1210_MAX_CLKIN) {
dev_err(dev, "ad2s1210: fclkin out of range\n");
return -EINVAL;
}
mutex_lock(&st->lock);
st->fclkin = fclkin;
ret = ad2s1210_update_frequency_control_word(st);
if (ret < 0)
goto error_ret;
ret = ad2s1210_soft_reset(st);
error_ret:
mutex_unlock(&st->lock);
return ret < 0 ? ret : len;
}
static ssize_t ad2s1210_show_fexcit(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
return sprintf(buf, "%u\n", st->fexcit);
}
static ssize_t ad2s1210_store_fexcit(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
unsigned int fexcit;
int ret;
ret = kstrtouint(buf, 10, &fexcit);
if (ret < 0)
return ret;
if (fexcit < AD2S1210_MIN_EXCIT || fexcit > AD2S1210_MAX_EXCIT) {
dev_err(dev,
"ad2s1210: excitation frequency out of range\n");
return -EINVAL;
}
mutex_lock(&st->lock);
st->fexcit = fexcit;
ret = ad2s1210_update_frequency_control_word(st);
if (ret < 0)
goto error_ret;
ret = ad2s1210_soft_reset(st);
error_ret:
mutex_unlock(&st->lock);
return ret < 0 ? ret : len;
}
static ssize_t ad2s1210_show_control(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
int ret;
mutex_lock(&st->lock);
ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
mutex_unlock(&st->lock);
return ret < 0 ? ret : sprintf(buf, "0x%x\n", ret);
}
static ssize_t ad2s1210_store_control(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
unsigned char udata;
unsigned char data;
int ret;
ret = kstrtou8(buf, 16, &udata);
if (ret)
return -EINVAL;
mutex_lock(&st->lock);
ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
if (ret < 0)
goto error_ret;
data = udata & AD2S1210_MSB_IS_LOW;
ret = ad2s1210_config_write(st, data);
if (ret < 0)
goto error_ret;
ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
if (ret < 0)
goto error_ret;
if (ret & AD2S1210_MSB_IS_HIGH) {
ret = -EIO;
dev_err(dev,
"ad2s1210: write control register fail\n");
goto error_ret;
}
st->resolution =
ad2s1210_resolution_value[data & AD2S1210_SET_RESOLUTION];
ad2s1210_set_resolution_pin(st);
ret = len;
st->hysteresis = !!(data & AD2S1210_ENABLE_HYSTERESIS);
error_ret:
mutex_unlock(&st->lock);
return ret;
}
static ssize_t ad2s1210_show_resolution(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
return sprintf(buf, "%d\n", st->resolution);
}
static ssize_t ad2s1210_store_resolution(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
unsigned char data;
unsigned char udata;
int ret;
ret = kstrtou8(buf, 10, &udata);
if (ret || udata < 10 || udata > 16) {
dev_err(dev, "ad2s1210: resolution out of range\n");
return -EINVAL;
}
mutex_lock(&st->lock);
ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
if (ret < 0)
goto error_ret;
data = ret;
data &= ~AD2S1210_SET_RESOLUTION;
data |= (udata - 10) >> 1;
ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
if (ret < 0)
goto error_ret;
ret = ad2s1210_config_write(st, data & AD2S1210_MSB_IS_LOW);
if (ret < 0)
goto error_ret;
ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
if (ret < 0)
goto error_ret;
data = ret;
if (data & AD2S1210_MSB_IS_HIGH) {
ret = -EIO;
dev_err(dev, "ad2s1210: setting resolution fail\n");
goto error_ret;
}
st->resolution =
ad2s1210_resolution_value[data & AD2S1210_SET_RESOLUTION];
ad2s1210_set_resolution_pin(st);
ret = len;
error_ret:
mutex_unlock(&st->lock);
return ret;
}
static ssize_t ad2s1210_show_fault(struct device *dev,
struct device_attribute *attr, char *buf)
{
struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
int ret;
mutex_lock(&st->lock);
ret = ad2s1210_config_read(st, AD2S1210_REG_FAULT);
mutex_unlock(&st->lock);
return ret ? ret : sprintf(buf, "0x%x\n", ret);
}
static ssize_t ad2s1210_clear_fault(struct device *dev,
struct device_attribute *attr,
const char *buf,
size_t len)
{
struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
int ret;
mutex_lock(&st->lock);
gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 0);
udelay(1);
gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 1);
ret = ad2s1210_config_read(st, AD2S1210_REG_FAULT);
if (ret < 0)
goto error_ret;
gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 0);
gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 1);
error_ret:
mutex_unlock(&st->lock);
return ret < 0 ? ret : len;
}
static ssize_t ad2s1210_show_reg(struct device *dev,
struct device_attribute *attr,
char *buf)
{
struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
struct iio_dev_attr *iattr = to_iio_dev_attr(attr);
int ret;
mutex_lock(&st->lock);
ret = ad2s1210_config_read(st, iattr->address);
mutex_unlock(&st->lock);
return ret < 0 ? ret : sprintf(buf, "%d\n", ret);
}
static ssize_t ad2s1210_store_reg(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t len)
{
struct ad2s1210_state *st = iio_priv(dev_to_iio_dev(dev));
unsigned char data;
int ret;
struct iio_dev_attr *iattr = to_iio_dev_attr(attr);
ret = kstrtou8(buf, 10, &data);
if (ret)
return -EINVAL;
mutex_lock(&st->lock);
ret = ad2s1210_config_write(st, iattr->address);
if (ret < 0)
goto error_ret;
ret = ad2s1210_config_write(st, data & AD2S1210_MSB_IS_LOW);
error_ret:
mutex_unlock(&st->lock);
return ret < 0 ? ret : len;
}
static int ad2s1210_read_raw(struct iio_dev *indio_dev,
struct iio_chan_spec const *chan,
int *val,
int *val2,
long m)
{
struct ad2s1210_state *st = iio_priv(indio_dev);
u16 negative;
int ret = 0;
u16 pos;
s16 vel;
mutex_lock(&st->lock);
gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 0);
udelay(1);
switch (chan->type) {
case IIO_ANGL:
ad2s1210_set_mode(MOD_POS, st);
break;
case IIO_ANGL_VEL:
ad2s1210_set_mode(MOD_VEL, st);
break;
default:
ret = -EINVAL;
break;
}
if (ret < 0)
goto error_ret;
ret = spi_read(st->sdev, st->rx, 2);
if (ret < 0)
goto error_ret;
switch (chan->type) {
case IIO_ANGL:
pos = be16_to_cpup((__be16 *)st->rx);
if (st->hysteresis)
pos >>= 16 - st->resolution;
*val = pos;
ret = IIO_VAL_INT;
break;
case IIO_ANGL_VEL:
vel = be16_to_cpup((__be16 *)st->rx);
vel >>= 16 - st->resolution;
if (vel & 0x8000) {
negative = (0xffff >> st->resolution) << st->resolution;
vel |= negative;
}
*val = vel;
ret = IIO_VAL_INT;
break;
default:
mutex_unlock(&st->lock);
return -EINVAL;
}
error_ret:
gpiod_set_value(st->gpios[AD2S1210_SAMPLE], 1);
udelay(1);
mutex_unlock(&st->lock);
return ret;
}
static IIO_DEVICE_ATTR(fclkin, 0644,
ad2s1210_show_fclkin, ad2s1210_store_fclkin, 0);
static IIO_DEVICE_ATTR(fexcit, 0644,
ad2s1210_show_fexcit, ad2s1210_store_fexcit, 0);
static IIO_DEVICE_ATTR(control, 0644,
ad2s1210_show_control, ad2s1210_store_control, 0);
static IIO_DEVICE_ATTR(bits, 0644,
ad2s1210_show_resolution, ad2s1210_store_resolution, 0);
static IIO_DEVICE_ATTR(fault, 0644,
ad2s1210_show_fault, ad2s1210_clear_fault, 0);
static IIO_DEVICE_ATTR(los_thrd, 0644,
ad2s1210_show_reg, ad2s1210_store_reg,
AD2S1210_REG_LOS_THRD);
static IIO_DEVICE_ATTR(dos_ovr_thrd, 0644,
ad2s1210_show_reg, ad2s1210_store_reg,
AD2S1210_REG_DOS_OVR_THRD);
static IIO_DEVICE_ATTR(dos_mis_thrd, 0644,
ad2s1210_show_reg, ad2s1210_store_reg,
AD2S1210_REG_DOS_MIS_THRD);
static IIO_DEVICE_ATTR(dos_rst_max_thrd, 0644,
ad2s1210_show_reg, ad2s1210_store_reg,
AD2S1210_REG_DOS_RST_MAX_THRD);
static IIO_DEVICE_ATTR(dos_rst_min_thrd, 0644,
ad2s1210_show_reg, ad2s1210_store_reg,
AD2S1210_REG_DOS_RST_MIN_THRD);
static IIO_DEVICE_ATTR(lot_high_thrd, 0644,
ad2s1210_show_reg, ad2s1210_store_reg,
AD2S1210_REG_LOT_HIGH_THRD);
static IIO_DEVICE_ATTR(lot_low_thrd, 0644,
ad2s1210_show_reg, ad2s1210_store_reg,
AD2S1210_REG_LOT_LOW_THRD);
static const struct iio_chan_spec ad2s1210_channels[] = {
{
.type = IIO_ANGL,
.indexed = 1,
.channel = 0,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
}, {
.type = IIO_ANGL_VEL,
.indexed = 1,
.channel = 0,
.info_mask_separate = BIT(IIO_CHAN_INFO_RAW),
}
};
static struct attribute *ad2s1210_attributes[] = {
&iio_dev_attr_fclkin.dev_attr.attr,
&iio_dev_attr_fexcit.dev_attr.attr,
&iio_dev_attr_control.dev_attr.attr,
&iio_dev_attr_bits.dev_attr.attr,
&iio_dev_attr_fault.dev_attr.attr,
&iio_dev_attr_los_thrd.dev_attr.attr,
&iio_dev_attr_dos_ovr_thrd.dev_attr.attr,
&iio_dev_attr_dos_mis_thrd.dev_attr.attr,
&iio_dev_attr_dos_rst_max_thrd.dev_attr.attr,
&iio_dev_attr_dos_rst_min_thrd.dev_attr.attr,
&iio_dev_attr_lot_high_thrd.dev_attr.attr,
&iio_dev_attr_lot_low_thrd.dev_attr.attr,
NULL,
};
static const struct attribute_group ad2s1210_attribute_group = {
.attrs = ad2s1210_attributes,
};
static int ad2s1210_initial(struct ad2s1210_state *st)
{
unsigned char data;
int ret;
mutex_lock(&st->lock);
ad2s1210_set_resolution_pin(st);
ret = ad2s1210_config_write(st, AD2S1210_REG_CONTROL);
if (ret < 0)
goto error_ret;
data = AD2S1210_DEF_CONTROL & ~(AD2S1210_SET_RESOLUTION);
data |= (st->resolution - 10) >> 1;
ret = ad2s1210_config_write(st, data);
if (ret < 0)
goto error_ret;
ret = ad2s1210_config_read(st, AD2S1210_REG_CONTROL);
if (ret < 0)
goto error_ret;
if (ret & AD2S1210_MSB_IS_HIGH) {
ret = -EIO;
goto error_ret;
}
ret = ad2s1210_update_frequency_control_word(st);
if (ret < 0)
goto error_ret;
ret = ad2s1210_soft_reset(st);
error_ret:
mutex_unlock(&st->lock);
return ret;
}
static const struct iio_info ad2s1210_info = {
.read_raw = ad2s1210_read_raw,
.attrs = &ad2s1210_attribute_group,
};
static int ad2s1210_setup_gpios(struct ad2s1210_state *st)
{
struct spi_device *spi = st->sdev;
int i, ret;
for (i = 0; i < ARRAY_SIZE(gpios); i++) {
st->gpios[i] = devm_gpiod_get(&spi->dev, gpios[i].name,
gpios[i].flags);
if (IS_ERR(st->gpios[i])) {
ret = PTR_ERR(st->gpios[i]);
dev_err(&spi->dev,
"ad2s1210: failed to request %s GPIO: %d\n",
gpios[i].name, ret);
return ret;
}
}
return 0;
}
static int ad2s1210_probe(struct spi_device *spi)
{
struct iio_dev *indio_dev;
struct ad2s1210_state *st;
int ret;
indio_dev = devm_iio_device_alloc(&spi->dev, sizeof(*st));
if (!indio_dev)
return -ENOMEM;
st = iio_priv(indio_dev);
ret = ad2s1210_setup_gpios(st);
if (ret < 0)
return ret;
spi_set_drvdata(spi, indio_dev);
mutex_init(&st->lock);
st->sdev = spi;
st->hysteresis = true;
st->mode = MOD_CONFIG;
st->resolution = 12;
st->fexcit = AD2S1210_DEF_EXCIT;
indio_dev->info = &ad2s1210_info;
indio_dev->modes = INDIO_DIRECT_MODE;
indio_dev->channels = ad2s1210_channels;
indio_dev->num_channels = ARRAY_SIZE(ad2s1210_channels);
indio_dev->name = spi_get_device_id(spi)->name;
ret = devm_iio_device_register(&spi->dev, indio_dev);
if (ret)
return ret;
st->fclkin = spi->max_speed_hz;
spi->mode = SPI_MODE_3;
spi_setup(spi);
ad2s1210_initial(st);
return 0;
}
static const struct of_device_id ad2s1210_of_match[] = {
{ .compatible = "adi,ad2s1210", },
{ }
};
MODULE_DEVICE_TABLE(of, ad2s1210_of_match);
static const struct spi_device_id ad2s1210_id[] = {
{ "ad2s1210" },
{}
};
MODULE_DEVICE_TABLE(spi, ad2s1210_id);
static struct spi_driver ad2s1210_driver = {
.driver = {
.name = DRV_NAME,
.of_match_table = of_match_ptr(ad2s1210_of_match),
},
.probe = ad2s1210_probe,
.id_table = ad2s1210_id,
};
module_spi_driver(ad2s1210_driver);
MODULE_AUTHOR("Graff Yang <graff.yang@gmail.com>");
MODULE_DESCRIPTION("Analog Devices AD2S1210 Resolver to Digital SPI driver");
MODULE_LICENSE("GPL v2"