On Thu, 6 May 2021 09:09:39 +0200
Sean Nyekjaer <sean@xxxxxxxxxx> wrote:
> When buffered sampling is enabled, the accelerometer will dump data into
> the internal fifo and interrupt at watermark. Then the driver flushes
> all data to the iio buffer.
> As the accelerometer doesn't have internal timestamps, they are
> approximated between the current and last interrupt.
>
> Signed-off-by: Sean Nyekjaer <sean@xxxxxxxxxx>
Hi Sean,
Couple of things I adjusted whilst applying this.
1) trigger.h isn't used as no triggers are involved currently in this driver so
I dropped it.
2) kfifo allocation etc has changed in the IIO core whilst this driver was in
development. Now we have devm_iio_kfifo_setup() which does everything your
locals _setup() function does.
I've made changes for both of the above whilst applying so please take a look
at the result which I'll shortly push out as testing for the autobuilders to
poke at as well.
Other than that I tweaked a bit of whilespace in the id tables in patch 1.
Series applied to the togreg branch of iio.git but initially just pushed out as
testing to let 0-day work it's magic.
Thanks,
Jonathan
> ---
> Changes from RFC:
> - Dropped the claim stuff for read_raw
> - Added watermark get/set
> - Consistent use of u16 for buffer size
>
> Changes for v5:
> - removed redundant blank lines and redundant assignments
>
> drivers/iio/accel/fxls8962af-core.c | 207 ++++++++++++++++++++++++++++
> 1 file changed, 207 insertions(+)
>
> diff --git a/drivers/iio/accel/fxls8962af-core.c b/drivers/iio/accel/fxls8962af-core.c
> index b909ba23e47c..889e470658b9 100644
> --- a/drivers/iio/accel/fxls8962af-core.c
> +++ b/drivers/iio/accel/fxls8962af-core.c
> @@ -20,13 +20,17 @@
> #include <linux/regulator/consumer.h>
> #include <linux/regmap.h>
>
> +#include <linux/iio/buffer.h>
> #include <linux/iio/iio.h>
> +#include <linux/iio/kfifo_buf.h>
> #include <linux/iio/sysfs.h>
> +#include <linux/iio/trigger.h>
>
> #include "fxls8962af.h"
>
> #define FXLS8962AF_INT_STATUS 0x00
> #define FXLS8962AF_INT_STATUS_SRC_BOOT BIT(0)
> +#define FXLS8962AF_INT_STATUS_SRC_BUF BIT(5)
> #define FXLS8962AF_INT_STATUS_SRC_DRDY BIT(7)
> #define FXLS8962AF_TEMP_OUT 0x01
> #define FXLS8962AF_VECM_LSB 0x02
> @@ -34,6 +38,9 @@
> #define FXLS8962AF_OUT_Y_LSB 0x06
> #define FXLS8962AF_OUT_Z_LSB 0x08
> #define FXLS8962AF_BUF_STATUS 0x0b
> +#define FXLS8962AF_BUF_STATUS_BUF_CNT GENMASK(5, 0)
> +#define FXLS8962AF_BUF_STATUS_BUF_OVF BIT(6)
> +#define FXLS8962AF_BUF_STATUS_BUF_WMRK BIT(7)
> #define FXLS8962AF_BUF_X_LSB 0x0c
> #define FXLS8962AF_BUF_Y_LSB 0x0e
> #define FXLS8962AF_BUF_Z_LSB 0x10
> @@ -66,6 +73,7 @@
> #define FXLS8962AF_ASLP_COUNT_LSB 0x1e
>
> #define FXLS8962AF_INT_EN 0x20
> +#define FXLS8962AF_INT_EN_BUF_EN BIT(6)
> #define FXLS8962AF_INT_PIN_SEL 0x21
> #define FXLS8962AF_INT_PIN_SEL_MASK GENMASK(7, 0)
> #define FXLS8962AF_INT_PIN_SEL_INT1 0x00
> @@ -76,7 +84,10 @@
> #define FXLS8962AF_OFF_Z 0x24
>
> #define FXLS8962AF_BUF_CONFIG1 0x26
> +#define FXLS8962AF_BC1_BUF_MODE_MASK GENMASK(6, 5)
> +#define FXLS8962AF_BC1_BUF_MODE_PREP(x) FIELD_PREP(FXLS8962AF_BC1_BUF_MODE_MASK, (x))
> #define FXLS8962AF_BUF_CONFIG2 0x27
> +#define FXLS8962AF_BUF_CONFIG2_BUF_WMRK GENMASK(5, 0)
>
> #define FXLS8962AF_ORIENT_STATUS 0x28
> #define FXLS8962AF_ORIENT_CONFIG 0x29
> @@ -106,6 +117,7 @@
>
> #define FXLS8962AF_AUTO_SUSPEND_DELAY_MS 2000
>
> +#define FXLS8962AF_FIFO_LENGTH 32
> #define FXLS8962AF_SCALE_TABLE_LEN 4
> #define FXLS8962AF_SAMP_FREQ_TABLE_LEN 13
>
> @@ -133,7 +145,13 @@ struct fxls8962af_data {
> struct regmap *regmap;
> const struct fxls8962af_chip_info *chip_info;
> struct regulator *vdd_reg;
> + struct {
> + __le16 channels[3];
> + s64 ts __aligned(8);
> + } scan;
> + int64_t timestamp, old_timestamp; /* Only used in hw fifo mode. */
> struct iio_mount_matrix orientation;
> + u8 watermark;
> };
>
> const struct regmap_config fxls8962af_regmap_conf = {
> @@ -433,6 +451,18 @@ static int fxls8962af_write_raw(struct iio_dev *indio_dev,
> }
> }
>
> +static int fxls8962af_set_watermark(struct iio_dev *indio_dev, unsigned val)
> +{
> + struct fxls8962af_data *data = iio_priv(indio_dev);
> +
> + if (val > FXLS8962AF_FIFO_LENGTH)
> + val = FXLS8962AF_FIFO_LENGTH;
> +
> + data->watermark = val;
> +
> + return 0;
> +}
> +
> #define FXLS8962AF_CHANNEL(axis, reg, idx) { \
> .type = IIO_ACCEL, \
> .address = reg, \
> @@ -493,6 +523,7 @@ static const struct iio_info fxls8962af_info = {
> .write_raw = &fxls8962af_write_raw,
> .write_raw_get_fmt = fxls8962af_write_raw_get_fmt,
> .read_avail = fxls8962af_read_avail,
> + .hwfifo_set_watermark = fxls8962af_set_watermark,
> };
>
> static int fxls8962af_reset(struct fxls8962af_data *data)
> @@ -517,6 +548,157 @@ static int fxls8962af_reset(struct fxls8962af_data *data)
> return ret;
> }
>
> +static int __fxls8962af_fifo_set_mode(struct fxls8962af_data *data, bool onoff)
> +{
> + int ret;
> +
> + /* Enable watermark at max fifo size */
> + ret = regmap_update_bits(data->regmap, FXLS8962AF_BUF_CONFIG2,
> + FXLS8962AF_BUF_CONFIG2_BUF_WMRK,
> + data->watermark);
> + if (ret)
> + return ret;
> +
> + return regmap_update_bits(data->regmap, FXLS8962AF_BUF_CONFIG1,
> + FXLS8962AF_BC1_BUF_MODE_MASK,
> + FXLS8962AF_BC1_BUF_MODE_PREP(onoff));
> +}
> +
> +static int fxls8962af_buffer_preenable(struct iio_dev *indio_dev)
> +{
> + return fxls8962af_power_on(iio_priv(indio_dev));
> +}
> +
> +static int fxls8962af_buffer_postenable(struct iio_dev *indio_dev)
> +{
> + struct fxls8962af_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + fxls8962af_standby(data);
> +
> + /* Enable buffer interrupt */
> + ret = regmap_update_bits(data->regmap, FXLS8962AF_INT_EN,
> + FXLS8962AF_INT_EN_BUF_EN,
> + FXLS8962AF_INT_EN_BUF_EN);
> + if (ret)
> + return ret;
> +
> + ret = __fxls8962af_fifo_set_mode(data, true);
> +
> + fxls8962af_active(data);
> +
> + return ret;
> +}
> +
> +static int fxls8962af_buffer_predisable(struct iio_dev *indio_dev)
> +{
> + struct fxls8962af_data *data = iio_priv(indio_dev);
> + int ret;
> +
> + fxls8962af_standby(data);
> +
> + /* Disable buffer interrupt */
> + ret = regmap_update_bits(data->regmap, FXLS8962AF_INT_EN,
> + FXLS8962AF_INT_EN_BUF_EN, 0);
> + if (ret)
> + return ret;
> +
> + ret = __fxls8962af_fifo_set_mode(data, false);
> +
> + fxls8962af_active(data);
> +
> + return ret;
> +}
> +
> +static int fxls8962af_buffer_postdisable(struct iio_dev *indio_dev)
> +{
> + struct fxls8962af_data *data = iio_priv(indio_dev);
> +
> + return fxls8962af_power_off(data);
> +}
> +
> +static const struct iio_buffer_setup_ops fxls8962af_buffer_ops = {
> + .preenable = fxls8962af_buffer_preenable,
> + .postenable = fxls8962af_buffer_postenable,
> + .predisable = fxls8962af_buffer_predisable,
> + .postdisable = fxls8962af_buffer_postdisable,
> +};
> +
> +static int fxls8962af_fifo_transfer(struct fxls8962af_data *data,
> + u16 *buffer, int samples)
> +{
> + struct device *dev = regmap_get_device(data->regmap);
> + int sample_length = 3 * sizeof(*buffer);
> + int ret;
> + int total_length = samples * sample_length;
> +
> + ret = regmap_raw_read(data->regmap, FXLS8962AF_BUF_X_LSB, buffer,
> + total_length);
> + if (ret)
> + dev_err(dev, "Error transferring data from fifo: %d\n", ret);
> +
> + return ret;
> +}
> +
> +static int fxls8962af_fifo_flush(struct iio_dev *indio_dev)
> +{
> + struct fxls8962af_data *data = iio_priv(indio_dev);
> + struct device *dev = regmap_get_device(data->regmap);
> + u16 buffer[FXLS8962AF_FIFO_LENGTH * 3];
> + uint64_t sample_period;
> + unsigned int reg;
> + int64_t tstamp;
> + int ret, i;
> + u8 count;
> +
> + ret = regmap_read(data->regmap, FXLS8962AF_BUF_STATUS, ®);
> + if (ret)
> + return ret;
> +
> + if (reg & FXLS8962AF_BUF_STATUS_BUF_OVF) {
> + dev_err(dev, "Buffer overflow");
> + return -EOVERFLOW;
> + }
> +
> + count = reg & FXLS8962AF_BUF_STATUS_BUF_CNT;
> + if (!count)
> + return 0;
> +
> + data->old_timestamp = data->timestamp;
> + data->timestamp = iio_get_time_ns(indio_dev);
> +
> + /*
> + * Approximate timestamps for each of the sample based on the sampling,
> + * frequency, timestamp for last sample and number of samples.
> + */
> + sample_period = (data->timestamp - data->old_timestamp);
> + do_div(sample_period, count);
> + tstamp = data->timestamp - (count - 1) * sample_period;
> +
> + ret = fxls8962af_fifo_transfer(data, buffer, count);
> + if (ret)
> + return ret;
> +
> + /* Demux hw FIFO into kfifo. */
> + for (i = 0; i < count; i++) {
> + int j, bit;
> +
> + j = 0;
> + for_each_set_bit(bit, indio_dev->active_scan_mask,
> + indio_dev->masklength) {
> + memcpy(&data->scan.channels[j++], &buffer[i * 3 + bit],
> + sizeof(data->scan.channels[0]));
> + }
> +
> + iio_push_to_buffers_with_timestamp(indio_dev, &data->scan,
> + tstamp);
> +
> + tstamp += sample_period;
> + }
> +
> + return count;
> +}
> +
> static irqreturn_t fxls8962af_interrupt(int irq, void *p)
> {
> struct iio_dev *indio_dev = p;
> @@ -528,9 +710,32 @@ static irqreturn_t fxls8962af_interrupt(int irq, void *p)
> if (ret)
> return IRQ_NONE;
>
> + if (reg & FXLS8962AF_INT_STATUS_SRC_BUF) {
> + ret = fxls8962af_fifo_flush(indio_dev);
> + if (ret)
> + return IRQ_NONE;
> +
> + return IRQ_HANDLED;
> + }
> +
> return IRQ_NONE;
> }
>
> +static int fxls8962af_fifo_setup(struct iio_dev *indio_dev)
> +{
> + struct iio_buffer *buffer;
> +
> + buffer = devm_iio_kfifo_allocate(&indio_dev->dev);
> + if (!buffer)
> + return -ENOMEM;
> +
> + iio_device_attach_buffer(indio_dev, buffer);
> + indio_dev->modes |= INDIO_BUFFER_SOFTWARE;
> + indio_dev->setup_ops = &fxls8962af_buffer_ops;
> +
> + return 0;
> +}
> +
> static void fxls8962af_regulator_disable(void *data_ptr)
> {
> struct fxls8962af_data *data = data_ptr;
> @@ -694,6 +899,8 @@ int fxls8962af_core_probe(struct device *dev, struct regmap *regmap, int irq)
> ret = fxls8962af_irq_setup(indio_dev, irq);
> if (ret)
> return ret;
> +
> + fxls8962af_fifo_setup(indio_dev);
> }
>
> ret = pm_runtime_set_active(dev);
