2016-10-17 3:08 GMT+09:00 Alison Schofield <amsfield22@xxxxxxxxx>:
> On Mon, Oct 17, 2016 at 12:59:42AM +0900, Akinobu Mita wrote:
>> This adds triggered buffer support for it-adc0832 driver. Tested with
>> ADC0831 and ADC0832 by using SYSFS trigger.
>>
>> Signed-off-by: Akinobu Mita <akinobu.mita@xxxxxxxxx>
>> Cc: Jonathan Cameron <jic23@xxxxxxxxxx>
>> Cc: Hartmut Knaack <knaack.h@xxxxxx>
>> Cc: Lars-Peter Clausen <lars@xxxxxxxxxx>
>> Cc: Peter Meerwald-Stadler <pmeerw@xxxxxxxxxx>
>> ---
>
> Hi Akinobu,
> I just scanned this looking for usage of iio_device_claim_direct_mode().
> I don't see it, so wondering if that is intentional. Do you want to
> allow both raw and buffered access at same time? If not, look at
> the iio_device_claim|release_direct_mode() functions.
> alisons
The triggered buffer handler added by this patch does nothing special
other than the ADC conversion by direct mode in this driver.
It just calls adc0832_adc_conversion() for each enabled scan element.
So I think protecting from multiple accesses by adc->lock is enough.
But I don't fully understand iio subsystem usages, please let me know
if there is a reason to use iio_device_claim_direct_mode() in this case.
>> drivers/iio/adc/Kconfig | 2 +
>> drivers/iio/adc/ti-adc0832.c | 106 +++++++++++++++++++++++++++++++++++--------
>> 2 files changed, 89 insertions(+), 19 deletions(-)
>>
>> diff --git a/drivers/iio/adc/Kconfig b/drivers/iio/adc/Kconfig
>> index 3dc60c0..bd8d108 100644
>> --- a/drivers/iio/adc/Kconfig
>> +++ b/drivers/iio/adc/Kconfig
>> @@ -457,6 +457,8 @@ config TI_ADC081C
>> config TI_ADC0832
>> tristate "Texas Instruments ADC0831/ADC0832/ADC0834/ADC0838"
>> depends on SPI
>> + select IIO_BUFFER
>> + select IIO_TRIGGERED_BUFFER
>> help
>> If you say yes here you get support for Texas Instruments ADC0831,
>> ADC0832, ADC0834, ADC0838 ADC chips.
>> diff --git a/drivers/iio/adc/ti-adc0832.c b/drivers/iio/adc/ti-adc0832.c
>> index f4ba23e..e952e94 100644
>> --- a/drivers/iio/adc/ti-adc0832.c
>> +++ b/drivers/iio/adc/ti-adc0832.c
>> @@ -14,6 +14,10 @@
>> #include <linux/spi/spi.h>
>> #include <linux/iio/iio.h>
>> #include <linux/regulator/consumer.h>
>> +#include <linux/iio/buffer.h>
>> +#include <linux/iio/trigger.h>
>> +#include <linux/iio/triggered_buffer.h>
>> +#include <linux/iio/trigger_consumer.h>
>>
>> enum {
>> adc0831,
>> @@ -38,10 +42,16 @@ struct adc0832 {
>> .indexed = 1, \
>> .channel = chan, \
>> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>> - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
>> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
>> + .scan_index = chan, \
>> + .scan_type = { \
>> + .sign = 'u', \
>> + .realbits = 8, \
>> + .storagebits = 8, \
>> + }, \
>> }
>>
>> -#define ADC0832_VOLTAGE_CHANNEL_DIFF(chan1, chan2) \
>> +#define ADC0832_VOLTAGE_CHANNEL_DIFF(chan1, chan2, si) \
>> { \
>> .type = IIO_VOLTAGE, \
>> .indexed = 1, \
>> @@ -49,18 +59,26 @@ struct adc0832 {
>> .channel2 = (chan2), \
>> .differential = 1, \
>> .info_mask_separate = BIT(IIO_CHAN_INFO_RAW), \
>> - .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE) \
>> + .info_mask_shared_by_type = BIT(IIO_CHAN_INFO_SCALE), \
>> + .scan_index = si, \
>> + .scan_type = { \
>> + .sign = 'u', \
>> + .realbits = 8, \
>> + .storagebits = 8, \
>> + }, \
>> }
>>
>> static const struct iio_chan_spec adc0831_channels[] = {
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1, 0),
>> + IIO_CHAN_SOFT_TIMESTAMP(1),
>> };
>>
>> static const struct iio_chan_spec adc0832_channels[] = {
>> ADC0832_VOLTAGE_CHANNEL(0),
>> ADC0832_VOLTAGE_CHANNEL(1),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1, 2),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0, 3),
>> + IIO_CHAN_SOFT_TIMESTAMP(4),
>> };
>>
>> static const struct iio_chan_spec adc0834_channels[] = {
>> @@ -68,10 +86,11 @@ static const struct iio_chan_spec adc0834_channels[] = {
>> ADC0832_VOLTAGE_CHANNEL(1),
>> ADC0832_VOLTAGE_CHANNEL(2),
>> ADC0832_VOLTAGE_CHANNEL(3),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(2, 3),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(3, 2),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1, 4),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0, 5),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(2, 3, 6),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(3, 2, 7),
>> + IIO_CHAN_SOFT_TIMESTAMP(8),
>> };
>>
>> static const struct iio_chan_spec adc0838_channels[] = {
>> @@ -83,14 +102,15 @@ static const struct iio_chan_spec adc0838_channels[] = {
>> ADC0832_VOLTAGE_CHANNEL(5),
>> ADC0832_VOLTAGE_CHANNEL(6),
>> ADC0832_VOLTAGE_CHANNEL(7),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(2, 3),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(3, 2),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(4, 5),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(5, 4),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(6, 7),
>> - ADC0832_VOLTAGE_CHANNEL_DIFF(7, 6),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(0, 1, 8),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(1, 0, 9),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(2, 3, 10),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(3, 2, 11),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(4, 5, 12),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(5, 4, 13),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(6, 7, 14),
>> + ADC0832_VOLTAGE_CHANNEL_DIFF(7, 6, 15),
>> + IIO_CHAN_SOFT_TIMESTAMP(16),
>> };
>>
>> static int adc0831_adc_conversion(struct adc0832 *adc)
>> @@ -178,6 +198,42 @@ static const struct iio_info adc0832_info = {
>> .driver_module = THIS_MODULE,
>> };
>>
>> +static irqreturn_t adc0832_trigger_handler(int irq, void *p)
>> +{
>> + struct iio_poll_func *pf = p;
>> + struct iio_dev *indio_dev = pf->indio_dev;
>> + struct adc0832 *adc = iio_priv(indio_dev);
>> + u8 data[24] = { }; /* 16x 1 byte ADC data + 8 bytes timestamp */
>> + int scan_index;
>> + int i = 0;
>> +
>> + mutex_lock(&adc->lock);
>> +
>> + for_each_set_bit(scan_index, indio_dev->active_scan_mask,
>> + indio_dev->masklength) {
>> + const struct iio_chan_spec *scan_chan =
>> + &indio_dev->channels[scan_index];
>> + int ret = adc0832_adc_conversion(adc, scan_chan->channel,
>> + scan_chan->differential);
>> + if (ret < 0) {
>> + dev_warn(&adc->spi->dev,
>> + "failed to get conversion data\n");
>> + goto out;
>> + }
>> +
>> + data[i] = ret;
>> + i++;
>> + }
>> + iio_push_to_buffers_with_timestamp(indio_dev, data,
>> + iio_get_time_ns(indio_dev));
>> +out:
>> + mutex_unlock(&adc->lock);
>> +
>> + iio_trigger_notify_done(indio_dev->trig);
>> +
>> + return IRQ_HANDLED;
>> +}
>> +
>> static int adc0832_probe(struct spi_device *spi)
>> {
>> struct iio_dev *indio_dev;
>> @@ -233,9 +289,20 @@ static int adc0832_probe(struct spi_device *spi)
>>
>> spi_set_drvdata(spi, indio_dev);
>>
>> + ret = iio_triggered_buffer_setup(indio_dev, NULL,
>> + adc0832_trigger_handler, NULL);
>> + if (ret)
>> + goto err_reg_disable;
>> +
>> ret = iio_device_register(indio_dev);
>> if (ret)
>> - regulator_disable(adc->reg);
>> + goto err_buffer_cleanup;
>> +
>> + return 0;
>> +err_buffer_cleanup:
>> + iio_triggered_buffer_cleanup(indio_dev);
>> +err_reg_disable:
>> + regulator_disable(adc->reg);
>>
>> return ret;
>> }
>> @@ -246,6 +313,7 @@ static int adc0832_remove(struct spi_device *spi)
>> struct adc0832 *adc = iio_priv(indio_dev);
>>
>> iio_device_unregister(indio_dev);
>> + iio_triggered_buffer_cleanup(indio_dev);
>> regulator_disable(adc->reg);
>>
>> return 0;
>> --
>> 2.7.4
>>
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