- 根目录:
- drivers
- iio
- imu
- adis.c
/*
* Common library for ADIS16XXX devices
*
* Copyright 2012 Analog Devices Inc.
* Author: Lars-Peter Clausen <lars@metafoo.de>
*
* Licensed under the GPL-2 or later.
*/
#include <linux/delay.h>
#include <linux/mutex.h>
#include <linux/device.h>
#include <linux/kernel.h>
#include <linux/spi/spi.h>
#include <linux/slab.h>
#include <linux/sysfs.h>
#include <linux/module.h>
#include <asm/unaligned.h>
#include <linux/iio/iio.h>
#include <linux/iio/sysfs.h>
#include <linux/iio/buffer.h>
#include <linux/iio/imu/adis.h>
#define ADIS_MSC_CTRL_DATA_RDY_EN BIT(2)
#define ADIS_MSC_CTRL_DATA_RDY_POL_HIGH BIT(1)
#define ADIS_MSC_CTRL_DATA_RDY_DIO2 BIT(0)
#define ADIS_GLOB_CMD_SW_RESET BIT(7)
int adis_write_reg(struct adis *adis, unsigned int reg,
unsigned int value, unsigned int size)
{
unsigned int page = reg / ADIS_PAGE_SIZE;
int ret, i;
struct spi_message msg;
struct spi_transfer xfers[] = {
{
.tx_buf = adis->tx,
.bits_per_word = 8,
.len = 2,
.cs_change = 1,
.delay_usecs = adis->data->write_delay,
}, {
.tx_buf = adis->tx + 2,
.bits_per_word = 8,
.len = 2,
.cs_change = 1,
.delay_usecs = adis->data->write_delay,
}, {
.tx_buf = adis->tx + 4,
.bits_per_word = 8,
.len = 2,
.cs_change = 1,
.delay_usecs = adis->data->write_delay,
}, {
.tx_buf = adis->tx + 6,
.bits_per_word = 8,
.len = 2,
.delay_usecs = adis->data->write_delay,
}, {
.tx_buf = adis->tx + 8,
.bits_per_word = 8,
.len = 2,
.delay_usecs = adis->data->write_delay,
},
};
mutex_lock(&adis->txrx_lock);
spi_message_init(&msg);
if (adis->current_page != page) {
adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
adis->tx[1] = page;
spi_message_add_tail(&xfers[0], &msg);
}
switch (size) {
case 4:
adis->tx[8] = ADIS_WRITE_REG(reg + 3);
adis->tx[9] = (value >> 24) & 0xff;
adis->tx[6] = ADIS_WRITE_REG(reg + 2);
adis->tx[7] = (value >> 16) & 0xff;
case 2:
adis->tx[4] = ADIS_WRITE_REG(reg + 1);
adis->tx[5] = (value >> 8) & 0xff;
case 1:
adis->tx[2] = ADIS_WRITE_REG(reg);
adis->tx[3] = value & 0xff;
break;
default:
ret = -EINVAL;
goto out_unlock;
}
xfers[size].cs_change = 0;
for (i = 1; i <= size; i++)
spi_message_add_tail(&xfers[i], &msg);
ret = spi_sync(adis->spi, &msg);
if (ret) {
dev_err(&adis->spi->dev, "Failed to write register 0x%02X: %d\n",
reg, ret);
} else {
adis->current_page = page;
}
out_unlock:
mutex_unlock(&adis->txrx_lock);
return ret;
}
EXPORT_SYMBOL_GPL(adis_write_reg);
/**
* adis_read_reg() - read 2 bytes from a 16-bit register
* @adis: The adis device
* @reg: The address of the lower of the two registers
* @val: The value read back from the device
*/
int adis_read_reg(struct adis *adis, unsigned int reg,
unsigned int *val, unsigned int size)
{
unsigned int page = reg / ADIS_PAGE_SIZE;
struct spi_message msg;
int ret;
struct spi_transfer xfers[] = {
{
.tx_buf = adis->tx,
.bits_per_word = 8,
.len = 2,
.cs_change = 1,
.delay_usecs = adis->data->write_delay,
}, {
.tx_buf = adis->tx + 2,
.bits_per_word = 8,
.len = 2,
.cs_change = 1,
.delay_usecs = adis->data->read_delay,
}, {
.tx_buf = adis->tx + 4,
.rx_buf = adis->rx,
.bits_per_word = 8,
.len = 2,
.cs_change = 1,
.delay_usecs = adis->data->read_delay,
}, {
.rx_buf = adis->rx + 2,
.bits_per_word = 8,
.len = 2,
.delay_usecs = adis->data->read_delay,
},
};
mutex_lock(&adis->txrx_lock);
spi_message_init(&msg);
if (adis->current_page != page) {
adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
adis->tx[1] = page;
spi_message_add_tail(&xfers[0], &msg);
}
switch (size) {
case 4:
adis->tx[2] = ADIS_READ_REG(reg + 2);
adis->tx[3] = 0;
spi_message_add_tail(&xfers[1], &msg);
case 2:
adis->tx[4] = ADIS_READ_REG(reg);
adis->tx[5] = 0;
spi_message_add_tail(&xfers[2], &msg);
spi_message_add_tail(&xfers[3], &msg);
break;
default:
ret = -EINVAL;
goto out_unlock;
}
ret = spi_sync(adis->spi, &msg);
if (ret) {
dev_err(&adis->spi->dev, "Failed to read register 0x%02X: %d\n",
reg, ret);
goto out_unlock;
} else {
adis->current_page = page;
}
switch (size) {
case 4:
*val = get_unaligned_be32(adis->rx);
break;
case 2:
*val = get_unaligned_be16(adis->rx + 2);
break;
}
out_unlock:
mutex_unlock(&adis->txrx_lock);
return ret;
}
EXPORT_SYMBOL_GPL(adis_read_reg);
#ifdef CONFIG_DEBUG_FS
int adis_debugfs_reg_access(struct iio_dev *indio_dev,
unsigned int reg, unsigned int writeval, unsigned int *readval)
{
struct adis *adis = iio_device_get_drvdata(indio_dev);
if (readval) {
uint16_t val16;
int ret;
ret = adis_read_reg_16(adis, reg, &val16);
*readval = val16;
return ret;
} else {
return adis_write_reg_16(adis, reg, writeval);
}
}
EXPORT_SYMBOL(adis_debugfs_reg_access);
#endif
/**
* adis_enable_irq() - Enable or disable data ready IRQ
* @adis: The adis device
* @enable: Whether to enable the IRQ
*
* Returns 0 on success, negative error code otherwise
*/
int adis_enable_irq(struct adis *adis, bool enable)
{
int ret = 0;
uint16_t msc;
if (adis->data->enable_irq)
return adis->data->enable_irq(adis, enable);
ret = adis_read_reg_16(adis, adis->data->msc_ctrl_reg, &msc);
if (ret)
goto error_ret;
msc |= ADIS_MSC_CTRL_DATA_RDY_POL_HIGH;
msc &= ~ADIS_MSC_CTRL_DATA_RDY_DIO2;
if (enable)
msc |= ADIS_MSC_CTRL_DATA_RDY_EN;
else
msc &= ~ADIS_MSC_CTRL_DATA_RDY_EN;
ret = adis_write_reg_16(adis, adis->data->msc_ctrl_reg, msc);
error_ret:
return ret;
}
EXPORT_SYMBOL(adis_enable_irq);
/**
* adis_check_status() - Check the device for error conditions
* @adis: The adis device
*
* Returns 0 on success, a negative error code otherwise
*/
int adis_check_status(struct adis *adis)
{
uint16_t status;
int ret;
int i;
ret = adis_read_reg_16(adis, adis->data->diag_stat_reg, &status);
if (ret < 0)
return ret;
status &= adis->data->status_error_mask;
if (status == 0)
return 0;
for (i = 0; i < 16; ++i) {
if (status & BIT(i)) {
dev_err(&adis->spi->dev, "%s.\n",
adis->data->status_error_msgs[i]);
}
}
return -EIO;
}
EXPORT_SYMBOL_GPL(adis_check_status);
/**
* adis_reset() - Reset the device
* @adis: The adis device
*
* Returns 0 on success, a negative error code otherwise
*/
int adis_reset(struct adis *adis)
{
int ret;
ret = adis_write_reg_8(adis, adis->data->glob_cmd_reg,
ADIS_GLOB_CMD_SW_RESET);
if (ret)
dev_err(&adis->spi->dev, "Failed to reset device: %d\n", ret);
return ret;
}
EXPORT_SYMBOL_GPL(adis_reset);
static int adis_self_test(struct adis *adis)
{
int ret;
ret = adis_write_reg_16(adis, adis->data->msc_ctrl_reg,
adis->data->self_test_mask);
if (ret) {
dev_err(&adis->spi->dev, "Failed to initiate self test: %d\n",
ret);
return ret;
}
msleep(adis->data->startup_delay);
return adis_check_status(adis);
}
/**
* adis_inital_startup() - Performs device self-test
* @adis: The adis device
*
* Returns 0 if the device is operational, a negative error code otherwise.
*
* This function should be called early on in the device initialization sequence
* to ensure that the device is in a sane and known state and that it is usable.
*/
int adis_initial_startup(struct adis *adis)
{
int ret;
ret = adis_self_test(adis);
if (ret) {
dev_err(&adis->spi->dev, "Self-test failed, trying reset.\n");
adis_reset(adis);
msleep(adis->data->startup_delay);
ret = adis_self_test(adis);
if (ret) {
dev_err(&adis->spi->dev, "Second self-test failed, giving up.\n");
return ret;
}
}
return 0;
}
EXPORT_SYMBOL_GPL(adis_initial_startup);
/**
* adis_single_conversion() - Performs a single sample conversion
* @indio_dev: The IIO device
* @chan: The IIO channel
* @error_mask: Mask for the error bit
* @val: Result of the conversion
*
* Returns IIO_VAL_INT on success, a negative error code otherwise.
*
* The function performs a single conversion on a given channel and post
* processes the value accordingly to the channel spec. If a error_mask is given
* the function will check if the mask is set in the returned raw value. If it
* is set the function will perform a self-check. If the device does not report
* a error bit in the channels raw value set error_mask to 0.
*/
int adis_single_conversion(struct iio_dev *indio_dev,
const struct iio_chan_spec *chan, unsigned int error_mask, int *val)
{
struct adis *adis = iio_device_get_drvdata(indio_dev);
unsigned int uval;
int ret;
mutex_lock(&indio_dev->mlock);
ret = adis_read_reg(adis, chan->address, &uval,
chan->scan_type.storagebits / 8);
if (ret)
goto err_unlock;
if (uval & error_mask) {
ret = adis_check_status(adis);
if (ret)
goto err_unlock;
}
if (chan->scan_type.sign == 's')
*val = sign_extend32(uval, chan->scan_type.realbits - 1);
else
*val = uval & ((1 << chan->scan_type.realbits) - 1);
ret = IIO_VAL_INT;
err_unlock:
mutex_unlock(&indio_dev->mlock);
return ret;
}
EXPORT_SYMBOL_GPL(adis_single_conversion);
/**
* adis_init() - Initialize adis device structure
* @adis: The adis device
* @indio_dev: The iio device
* @spi: The spi device
* @data: Chip specific data
*
* Returns 0 on success, a negative error code otherwise.
*
* This function must be called, before any other adis helper function may be
* called.
*/
int adis_init(struct adis *adis, struct iio_dev *indio_dev,
struct spi_device *spi, const struct adis_data *data)
{
mutex_init(&adis->txrx_lock);
adis->spi = spi;
adis->data = data;
iio_device_set_drvdata(indio_dev, adis);
if (data->has_paging) {
/* Need to set the page before first read/write */
adis->current_page = -1;
} else {
/* Page will always be 0 */
adis->current_page = 0;
}
return adis_enable_irq(adis, false);
}
EXPORT_SYMBOL_GPL(adis_init);
MODULE_LICENSE("GPL");
MODULE_AUTHOR("Lars-Peter Clausen <lars@metafoo.de>");
MODULE_DESCRIPTION("Common library code for ADIS16XXX devices");