On Wed, 4 Oct 2023 at 20:26, Mukesh Ojha <quic_mojha@xxxxxxxxxxx> wrote:
>
> It was realized by Srinivas K. that there is a need of
> read-modify-write scm exported function so that it can
> be used by multiple clients.
>
> Let's introduce qcom_scm_io_update_field() which masks
> out the bits and write the passed value to that bit-offset.
>
> Suggested-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> Signed-off-by: Mukesh Ojha <quic_mojha@xxxxxxxxxxx>
> Tested-by: Kathiravan Thirumoorthy <quic_kathirav@xxxxxxxxxxx> # IPQ9574 and IPQ5332
> ---
> drivers/firmware/qcom_scm.c | 20 ++++++++++++++++++++
> include/linux/firmware/qcom/qcom_scm.h | 2 ++
> 2 files changed, 22 insertions(+)
>
> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> index 520de9b5633a..084e4782b88d 100644
> --- a/drivers/firmware/qcom_scm.c
> +++ b/drivers/firmware/qcom_scm.c
> @@ -122,6 +122,7 @@ static const char * const qcom_scm_convention_names[] = {
> };
>
> static struct qcom_scm *__scm;
> +static DEFINE_SPINLOCK(lock);
Please move the spinlock inside __scm.
>
> static int qcom_scm_clk_enable(void)
> {
> @@ -481,6 +482,25 @@ static int qcom_scm_disable_sdi(void)
> return ret ? : res.result[0];
> }
>
> +int qcom_scm_io_update_field(phys_addr_t addr, unsigned int mask, unsigned int val)
qcom_scm_io_rmw ? qcom_scm_io_update_bits? These might be better names
and they follow the existing function names.
> +{
> + unsigned int old, new;
> + int ret;
> +
> + spin_lock(&lock);
> + ret = qcom_scm_io_readl(addr, &old);
> + if (ret)
> + goto unlock;
> +
> + new = (old & ~mask) | (val & mask);
> +
> + ret = qcom_scm_io_writel(addr, new);
> +unlock:
> + spin_unlock(&lock);
> + return ret;
> +}
> +EXPORT_SYMBOL_GPL(qcom_scm_io_update_field);
> +
> static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
> {
> struct qcom_scm_desc desc = {
> diff --git a/include/linux/firmware/qcom/qcom_scm.h b/include/linux/firmware/qcom/qcom_scm.h
> index ccaf28846054..5497eaf9c7b5 100644
> --- a/include/linux/firmware/qcom/qcom_scm.h
> +++ b/include/linux/firmware/qcom/qcom_scm.h
> @@ -82,6 +82,8 @@ bool qcom_scm_pas_supported(u32 peripheral);
>
> int qcom_scm_io_readl(phys_addr_t addr, unsigned int *val);
> int qcom_scm_io_writel(phys_addr_t addr, unsigned int val);
> +int qcom_scm_io_update_field(phys_addr_t addr, unsigned int mask,
> + unsigned int val);
>
> bool qcom_scm_restore_sec_cfg_available(void);
> int qcom_scm_restore_sec_cfg(u32 device_id, u32 spare);
> --
> 2.7.4
>
--
With best wishes
Dmitry
