On Wed, 29 Jan 2025 10:20:43 +0200
Robert Budai <robert.budai@xxxxxxxxxx> wrote:
> Some devices may have more than 16 bits of status. This patch allows the
> user to specify the size of the DIAG_STAT register. It defaults to 2 if
> not specified. This is mainly for backward compatibility.
>
> Co-developed-by: Ramona Gradinariu <ramona.gradinariu@xxxxxxxxxx>
> Signed-off-by: Ramona Gradinariu <ramona.gradinariu@xxxxxxxxxx>
> Co-developed-by: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>
> Signed-off-by: Antoniu Miclaus <antoniu.miclaus@xxxxxxxxxx>
> Signed-off-by: Nuno Sá <nuno.sa@xxxxxxxxxx>
> Signed-off-by: Robert Budai <robert.budai@xxxxxxxxxx>
> ---
>
> v5:
> - added local variable
> - mentioned default handling of diag_stat_size in comments
>
> drivers/iio/imu/adis.c | 14 +++++++++++---
> include/linux/iio/imu/adis.h | 3 +++
> 2 files changed, 14 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/iio/imu/adis.c b/drivers/iio/imu/adis.c
> index 84344f052fb7..57e724412f52 100644
> --- a/drivers/iio/imu/adis.c
> +++ b/drivers/iio/imu/adis.c
> @@ -304,11 +304,16 @@ EXPORT_SYMBOL_NS(__adis_enable_irq, "IIO_ADISLIB");
> */
> int __adis_check_status(struct adis *adis)
> {
> - u16 status;
> + unsigned int status;
> + int diag_stat_bits;
> int ret;
> int i;
>
> - ret = __adis_read_reg_16(adis, adis->data->diag_stat_reg, &status);
> + if (adis->data->diag_stat_size)
> + ret = adis->ops->read(adis, adis->data->diag_stat_reg, &status,
> + adis->data->diag_stat_size);
> + else
> + ret = __adis_read_reg_16(adis, adis->data->diag_stat_reg, (u16 *)&status);
You can't just cast a pointer like this. What happens will depend on endianness
of the host CPU. Use a local variable for the u16 then set status = status16
or something like that.
> if (ret)
> return ret;
>
> @@ -317,7 +322,10 @@ int __adis_check_status(struct adis *adis)
> if (status == 0)
> return 0;
>
> - for (i = 0; i < 16; ++i) {
> + diag_stat_bits = BITS_PER_BYTE * (adis->data->diag_stat_size ?
> + adis->data->diag_stat_size : 2);
> +
> + for (i = 0; i < diag_stat_bits; ++i) {
> if (status & BIT(i)) {
> dev_err(&adis->spi->dev, "%s.\n",
> adis->data->status_error_msgs[i]);
> diff --git a/include/linux/iio/imu/adis.h b/include/linux/iio/imu/adis.h
> index 13beb6a7317b..ad40fb95fcdc 100644
> --- a/include/linux/iio/imu/adis.h
> +++ b/include/linux/iio/imu/adis.h
> @@ -44,6 +44,8 @@ struct adis_timeout {
> * @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
> + * @diag_stat_size: Length (in bytes) of the DIAG_STAT register. If not
> + * defined, default value is 2 bytes long.
If 0, rather than not defined (it's defined whatever, just a question of what
value it has!)
> * @prod_id_reg: Register address of the PROD_ID register
> * @prod_id: Product ID code that should be expected when reading @prod_id_reg
> * @self_test_mask: Bitmask of supported self-test operations
> @@ -70,6 +72,7 @@ struct adis_data {
> unsigned int glob_cmd_reg;
> unsigned int msc_ctrl_reg;
> unsigned int diag_stat_reg;
> + unsigned int diag_stat_size;
> unsigned int prod_id_reg;
>
> unsigned int prod_id;
