diff options
Diffstat (limited to 'drivers/iio/imu/adis_buffer.c')
| -rw-r--r-- | drivers/iio/imu/adis_buffer.c | 159 |
1 files changed, 159 insertions, 0 deletions
diff --git a/drivers/iio/imu/adis_buffer.c b/drivers/iio/imu/adis_buffer.c new file mode 100644 index 00000000000..a91b4cbdc73 --- /dev/null +++ b/drivers/iio/imu/adis_buffer.c @@ -0,0 +1,159 @@ +/* + * 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/export.h> +#include <linux/interrupt.h> +#include <linux/mutex.h> +#include <linux/kernel.h> +#include <linux/spi/spi.h> +#include <linux/slab.h> + +#include <linux/iio/iio.h> +#include <linux/iio/buffer.h> +#include <linux/iio/trigger_consumer.h> +#include <linux/iio/triggered_buffer.h> +#include <linux/iio/imu/adis.h> + +int adis_update_scan_mode(struct iio_dev *indio_dev, + const unsigned long *scan_mask) +{ + struct adis *adis = iio_device_get_drvdata(indio_dev); + const struct iio_chan_spec *chan; + unsigned int scan_count; + unsigned int i, j; + __be16 *tx, *rx; + + kfree(adis->xfer); + kfree(adis->buffer); + + scan_count = indio_dev->scan_bytes / 2; + + adis->xfer = kcalloc(scan_count + 1, sizeof(*adis->xfer), GFP_KERNEL); + if (!adis->xfer) + return -ENOMEM; + + adis->buffer = kzalloc(indio_dev->scan_bytes * 2, GFP_KERNEL); + if (!adis->buffer) + return -ENOMEM; + + rx = adis->buffer; + tx = rx + indio_dev->scan_bytes; + + spi_message_init(&adis->msg); + + for (j = 0; j <= scan_count; j++) { + adis->xfer[j].bits_per_word = 8; + if (j != scan_count) + adis->xfer[j].cs_change = 1; + adis->xfer[j].len = 2; + adis->xfer[j].delay_usecs = adis->data->read_delay; + if (j < scan_count) + adis->xfer[j].tx_buf = &tx[j]; + if (j >= 1) + adis->xfer[j].rx_buf = &rx[j - 1]; + spi_message_add_tail(&adis->xfer[j], &adis->msg); + } + + chan = indio_dev->channels; + for (i = 0; i < indio_dev->num_channels; i++, chan++) { + if (!test_bit(chan->scan_index, scan_mask)) + continue; + *tx++ = cpu_to_be16(chan->address << 8); + } + + return 0; +} +EXPORT_SYMBOL_GPL(adis_update_scan_mode); + +static irqreturn_t adis_trigger_handler(int irq, void *p) +{ + struct iio_poll_func *pf = p; + struct iio_dev *indio_dev = pf->indio_dev; + struct adis *adis = iio_device_get_drvdata(indio_dev); + int ret; + + if (!adis->buffer) + return -ENOMEM; + + ret = spi_sync(adis->spi, &adis->msg); + if (ret) + dev_err(&adis->spi->dev, "Failed to read data: %d", ret); + + /* Guaranteed to be aligned with 8 byte boundary */ + if (indio_dev->scan_timestamp) { + void *b = adis->buffer + indio_dev->scan_bytes - sizeof(s64); + *(s64 *)b = pf->timestamp; + } + + iio_push_to_buffers(indio_dev, adis->buffer); + + iio_trigger_notify_done(indio_dev->trig); + + return IRQ_HANDLED; +} + +/** + * adis_setup_buffer_and_trigger() - Sets up buffer and trigger for the adis device + * @adis: The adis device. + * @indio_dev: The IIO device. + * @trigger_handler: Optional trigger handler, may be NULL. + * + * Returns 0 on success, a negative error code otherwise. + * + * This function sets up the buffer and trigger for a adis devices. If + * 'trigger_handler' is NULL the default trigger handler will be used. The + * default trigger handler will simply read the registers assigned to the + * currently active channels. + * + * adis_cleanup_buffer_and_trigger() should be called to free the resources + * allocated by this function. + */ +int adis_setup_buffer_and_trigger(struct adis *adis, struct iio_dev *indio_dev, + irqreturn_t (*trigger_handler)(int, void *)) +{ + int ret; + + if (!trigger_handler) + trigger_handler = adis_trigger_handler; + + ret = iio_triggered_buffer_setup(indio_dev, &iio_pollfunc_store_time, + trigger_handler, NULL); + if (ret) + return ret; + + if (adis->spi->irq) { + ret = adis_probe_trigger(adis, indio_dev); + if (ret) + goto error_buffer_cleanup; + } + return 0; + +error_buffer_cleanup: + iio_triggered_buffer_cleanup(indio_dev); + return ret; +} +EXPORT_SYMBOL_GPL(adis_setup_buffer_and_trigger); + +/** + * adis_cleanup_buffer_and_trigger() - Free buffer and trigger resources + * @adis: The adis device. + * @indio_dev: The IIO device. + * + * Frees resources allocated by adis_setup_buffer_and_trigger() + */ +void adis_cleanup_buffer_and_trigger(struct adis *adis, + struct iio_dev *indio_dev) +{ + if (adis->spi->irq) + adis_remove_trigger(adis); + kfree(adis->buffer); + kfree(adis->xfer); + iio_triggered_buffer_cleanup(indio_dev); +} +EXPORT_SYMBOL_GPL(adis_cleanup_buffer_and_trigger); |