Re: [PATCH 1/3][V4] iio: imu: adis: Add support for SPI transfer cs_change_delay

[Jonathan Cameron <jic23@xxxxxxxxxx>]

On Tue, 23 Jul 2019 10:36:38 +0300
Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx> wrote:

> The ADIS16460 requires a higher delay before the next transfer. Since the
> SPI framework supports configuring the delay before the next transfer, this
> driver will become the first user of it.
> 
> The support for this functionality in ADIS16460 requires an addition to the
> ADIS lib to support the `cs_change_delay` functionality from the SPI
> subsystem.
> 
> Signed-off-by: Michael Hennerich <michael.hennerich@xxxxxxxxxx>
> Signed-off-by: Alexandru Ardelean <alexandru.ardelean@xxxxxxxxxx>
Applied to the togreg branch of iio.git and pushed out as testing for
the autobuilders to play with it.

Thanks,

Jonathan

> ---
>  drivers/iio/imu/adis.c       | 12 ++++++++++++
>  include/linux/iio/imu/adis.h |  2 ++
>  2 files changed, 14 insertions(+)
> 
> diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c
> index 30281e91dbf9..1631c255deab 100644
> --- a/drivers/iio/imu/adis.c
> +++ b/drivers/iio/imu/adis.c
> @@ -39,18 +39,24 @@ int adis_write_reg(struct adis *adis, unsigned int reg,
>  			.len = 2,
>  			.cs_change = 1,
>  			.delay_usecs = adis->data->write_delay,
> +			.cs_change_delay = adis->data->cs_change_delay,
> +			.cs_change_delay_unit = SPI_DELAY_UNIT_USECS,
>  		}, {
>  			.tx_buf = adis->tx + 2,
>  			.bits_per_word = 8,
>  			.len = 2,
>  			.cs_change = 1,
>  			.delay_usecs = adis->data->write_delay,
> +			.cs_change_delay = adis->data->cs_change_delay,
> +			.cs_change_delay_unit = SPI_DELAY_UNIT_USECS,
>  		}, {
>  			.tx_buf = adis->tx + 4,
>  			.bits_per_word = 8,
>  			.len = 2,
>  			.cs_change = 1,
>  			.delay_usecs = adis->data->write_delay,
> +			.cs_change_delay = adis->data->cs_change_delay,
> +			.cs_change_delay_unit = SPI_DELAY_UNIT_USECS,
>  		}, {
>  			.tx_buf = adis->tx + 6,
>  			.bits_per_word = 8,
> @@ -133,12 +139,16 @@ int adis_read_reg(struct adis *adis, unsigned int reg,
>  			.len = 2,
>  			.cs_change = 1,
>  			.delay_usecs = adis->data->write_delay,
> +			.cs_change_delay = adis->data->cs_change_delay,
> +			.cs_change_delay_unit = SPI_DELAY_UNIT_USECS,
>  		}, {
>  			.tx_buf = adis->tx + 2,
>  			.bits_per_word = 8,
>  			.len = 2,
>  			.cs_change = 1,
>  			.delay_usecs = adis->data->read_delay,
> +			.cs_change_delay = adis->data->cs_change_delay,
> +			.cs_change_delay_unit = SPI_DELAY_UNIT_USECS,
>  		}, {
>  			.tx_buf = adis->tx + 4,
>  			.rx_buf = adis->rx,
> @@ -146,6 +156,8 @@ int adis_read_reg(struct adis *adis, unsigned int reg,
>  			.len = 2,
>  			.cs_change = 1,
>  			.delay_usecs = adis->data->read_delay,
> +			.cs_change_delay = adis->data->cs_change_delay,
> +			.cs_change_delay_unit = SPI_DELAY_UNIT_USECS,
>  		}, {
>  			.rx_buf = adis->rx + 2,
>  			.bits_per_word = 8,
> diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h
> index 3428d06b2f44..4c53815bb729 100644
> --- a/include/linux/iio/imu/adis.h
> +++ b/include/linux/iio/imu/adis.h
> @@ -26,6 +26,7 @@ struct adis_burst;
>   * struct adis_data - ADIS chip variant specific data
>   * @read_delay: SPI delay for read operations in us
>   * @write_delay: SPI delay for write operations in us
> + * @cs_change_delay: SPI delay between CS changes in us
>   * @glob_cmd_reg: Register address of the GLOB_CMD register
>   * @msc_ctrl_reg: Register address of the MSC_CTRL register
>   * @diag_stat_reg: Register address of the DIAG_STAT register
> @@ -35,6 +36,7 @@ struct adis_burst;
>  struct adis_data {
>  	unsigned int read_delay;
>  	unsigned int write_delay;
> +	unsigned int cs_change_delay;
>  
>  	unsigned int glob_cmd_reg;
>  	unsigned int msc_ctrl_reg;