diff options
Diffstat (limited to 'drivers/iio/imu/adis.c')
| -rw-r--r-- | drivers/iio/imu/adis.c | 337 |
1 files changed, 337 insertions, 0 deletions
diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c new file mode 100644 index 000000000000..8259b774078f --- /dev/null +++ b/drivers/iio/imu/adis.c @@ -0,0 +1,337 @@ +/* + * 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) + +/** + * adis_write_reg_8() - Write single byte to a register + * @adis: The adis device + * @reg: The address of the register to be written + * @val: The value to write + */ +int adis_write_reg_8(struct adis *adis, unsigned int reg, uint8_t val) +{ + int ret; + + mutex_lock(&adis->txrx_lock); + adis->tx[0] = ADIS_WRITE_REG(reg); + adis->tx[1] = val; + + ret = spi_write(adis->spi, adis->tx, 2); + mutex_unlock(&adis->txrx_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(adis_write_reg_8); + +/** + * adis_write_reg_16() - Write 2 bytes to a pair of registers + * @adis: The adis device + * @reg: The address of the lower of the two registers + * @val: Value to be written + */ +int adis_write_reg_16(struct adis *adis, unsigned int reg, uint16_t value) +{ + int ret; + 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, + .delay_usecs = adis->data->write_delay, + }, + }; + + mutex_lock(&adis->txrx_lock); + adis->tx[0] = ADIS_WRITE_REG(reg); + adis->tx[1] = value & 0xff; + adis->tx[2] = ADIS_WRITE_REG(reg + 1); + adis->tx[3] = (value >> 8) & 0xff; + + spi_message_init(&msg); + spi_message_add_tail(&xfers[0], &msg); + spi_message_add_tail(&xfers[1], &msg); + ret = spi_sync(adis->spi, &msg); + mutex_unlock(&adis->txrx_lock); + + return ret; +} +EXPORT_SYMBOL_GPL(adis_write_reg_16); + +/** + * adis_read_reg_16() - 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_16(struct adis *adis, unsigned int reg, uint16_t *val) +{ + 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->read_delay, + }, { + .rx_buf = adis->rx, + .bits_per_word = 8, + .len = 2, + .delay_usecs = adis->data->read_delay, + }, + }; + + mutex_lock(&adis->txrx_lock); + adis->tx[0] = ADIS_READ_REG(reg); + adis->tx[1] = 0; + + spi_message_init(&msg); + spi_message_add_tail(&xfers[0], &msg); + spi_message_add_tail(&xfers[1], &msg); + ret = spi_sync(adis->spi, &msg); + if (ret) { + dev_err(&adis->spi->dev, "Failed to read 16 bit register 0x%02X: %d\n", + reg, ret); + goto error_ret; + } + *val = get_unaligned_be16(adis->rx); + +error_ret: + mutex_unlock(&adis->txrx_lock); + return ret; +} +EXPORT_SYMBOL_GPL(adis_read_reg_16); + +/** + * 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; + + 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); + uint16_t val16; + int ret; + + mutex_lock(&indio_dev->mlock); + + ret = adis_read_reg_16(adis, chan->address, &val16); + if (ret) + goto err_unlock; + + if (val16 & error_mask) { + ret = adis_check_status(adis); + if (ret) + goto err_unlock; + } + + if (chan->scan_type.sign == 's') + *val = sign_extend32(val16, chan->scan_type.realbits - 1); + else + *val = val16 & ((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); + + 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"); |