linux/drivers/iio/imu/adis_buffer.c
Nuno Sá 36e322ec5d iio: adis: Move burst mode into adis_data
Add burst mode variables in the per device specific data structure. As
some drivers support multiple devices with different burst sizes it
makes sense this data to be in `adis_data`. While moving the variables,
there are two main differences:

1. The `en`variable is dropped. If a device supports burst mode, it will
just use it as it will has better performance for almost all real use
cases.
2. Replace `extra_len` by `burst_len`. Users should now explicitly
define the length of the burst buffer as it is typically constant. This
also allows to remove the following line from the library:

```
/* All but the timestamp channel */
burst_length = (indio_dev->num_channels - 1) * sizeof(u16);
```

The library should not assume that a timestamp channel is defined.
Moreover, most parts also include some diagnostic data, crc, etc.. in
the burst buffer that needed to be included in an `extra_len` variable
which is not that nice. On top of this, some devices already start to
have some 32bit size channels ...

This patch is also a move to completely drop the `struct adis_burst`
from the library.

Signed-off-by: Nuno Sá <nuno.sa@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Link: https://lore.kernel.org/r/20200917155223.218500-2-nuno.sa@analog.com
2020-09-21 20:01:45 +01:00

210 lines
5.1 KiB
C

// SPDX-License-Identifier: GPL-2.0-or-later
/*
* Common library for ADIS16XXX devices
*
* Copyright 2012 Analog Devices Inc.
* Author: Lars-Peter Clausen <lars@metafoo.de>
*/
#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>
static int adis_update_scan_mode_burst(struct iio_dev *indio_dev,
const unsigned long *scan_mask)
{
struct adis *adis = iio_device_get_drvdata(indio_dev);
unsigned int burst_length, burst_max_length;
u8 *tx;
burst_length = adis->data->burst_len + adis->burst_extra_len;
if (adis->data->burst_max_len)
burst_max_length = adis->data->burst_max_len;
else
burst_max_length = burst_length;
adis->xfer = kcalloc(2, sizeof(*adis->xfer), GFP_KERNEL);
if (!adis->xfer)
return -ENOMEM;
adis->buffer = kzalloc(burst_max_length + sizeof(u16), GFP_KERNEL);
if (!adis->buffer) {
kfree(adis->xfer);
adis->xfer = NULL;
return -ENOMEM;
}
tx = adis->buffer + burst_max_length;
tx[0] = ADIS_READ_REG(adis->data->burst_reg_cmd);
tx[1] = 0;
adis->xfer[0].tx_buf = tx;
adis->xfer[0].bits_per_word = 8;
adis->xfer[0].len = 2;
adis->xfer[1].rx_buf = adis->buffer;
adis->xfer[1].bits_per_word = 8;
adis->xfer[1].len = burst_length;
spi_message_init(&adis->msg);
spi_message_add_tail(&adis->xfer[0], &adis->msg);
spi_message_add_tail(&adis->xfer[1], &adis->msg);
return 0;
}
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);
if (adis->data->burst_len)
return adis_update_scan_mode_burst(indio_dev, scan_mask);
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 = kcalloc(indio_dev->scan_bytes, 2, GFP_KERNEL);
if (!adis->buffer) {
kfree(adis->xfer);
adis->xfer = NULL;
return -ENOMEM;
}
rx = adis->buffer;
tx = rx + scan_count;
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.value = adis->data->read_delay;
adis->xfer[j].delay.unit = SPI_DELAY_UNIT_USECS;
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;
if (chan->scan_type.storagebits == 32)
*tx++ = cpu_to_be16((chan->address + 2) << 8);
*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;
if (adis->data->has_paging) {
mutex_lock(&adis->state_lock);
if (adis->current_page != 0) {
adis->tx[0] = ADIS_WRITE_REG(ADIS_REG_PAGE_ID);
adis->tx[1] = 0;
spi_write(adis->spi, adis->tx, 2);
}
}
ret = spi_sync(adis->spi, &adis->msg);
if (ret)
dev_err(&adis->spi->dev, "Failed to read data: %d", ret);
if (adis->data->has_paging) {
adis->current_page = 0;
mutex_unlock(&adis->state_lock);
}
iio_push_to_buffers_with_timestamp(indio_dev, adis->buffer,
pf->timestamp);
iio_trigger_notify_done(indio_dev->trig);
return IRQ_HANDLED;
}
static void adis_buffer_cleanup(void *arg)
{
struct adis *adis = arg;
kfree(adis->buffer);
kfree(adis->xfer);
}
/**
* devm_adis_setup_buffer_and_trigger() - Sets up buffer and trigger for
* the managed 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.
*/
int
devm_adis_setup_buffer_and_trigger(struct adis *adis, struct iio_dev *indio_dev,
irq_handler_t trigger_handler)
{
int ret;
if (!trigger_handler)
trigger_handler = adis_trigger_handler;
ret = devm_iio_triggered_buffer_setup(&adis->spi->dev, indio_dev,
&iio_pollfunc_store_time,
trigger_handler, NULL);
if (ret)
return ret;
if (adis->spi->irq) {
ret = devm_adis_probe_trigger(adis, indio_dev);
if (ret)
return ret;
}
return devm_add_action_or_reset(&adis->spi->dev, adis_buffer_cleanup,
adis);
}
EXPORT_SYMBOL_GPL(devm_adis_setup_buffer_and_trigger);