Re: [PATCH v5 13/17] firmware: qcom_scm: provide a read-modify-write function

[Kathiravan Thirumoorthy <quic_kathirav@xxxxxxxxxxx>]

On 9/11/2023 1:38 PM, Kathiravan Thirumoorthy wrote:
> On 9/10/2023 1:46 AM, Mukesh Ojha 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. Subsequent patch will use this function.
> >
> > Suggested-by: Srinivas Kandagatla <srinivas.kandagatla@xxxxxxxxxx>
> > Signed-off-by: Mukesh Ojha <quic_mojha@xxxxxxxxxxx>
> > ---
>
>
> Validated this change on IPQ9574 and IPQ53332 and system is entering 
> into the download mode.
>
> Tested-by: Kathiravan Thirumoorthy <quic_kathirav@xxxxxxxxxxx> # 
> IP9574 and IPQ5332


Couple of typos. Apologize...

Validated this change on IPQ9574 and IPQ5332 and system is entering into 
the download mode.

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 fde33acd46b7..5ea8fc4fd4e8 100644
> > --- a/drivers/firmware/qcom_scm.c
> > +++ b/drivers/firmware/qcom_scm.c
> > @@ -78,6 +78,7 @@ static const char * const 
> > qcom_scm_convention_names[] = {
> >   };
> >     static struct qcom_scm *__scm;
> > +static DEFINE_SPINLOCK(lock);
> >     static int qcom_scm_clk_enable(void)
> >   {
> > @@ -407,6 +408,25 @@ int qcom_scm_set_remote_state(u32 state, u32 id)
> >   }
> >   EXPORT_SYMBOL(qcom_scm_set_remote_state);
> >   +int qcom_scm_io_update_field(phys_addr_t addr, unsigned int mask, 
> > unsigned int val)
> > +{
> > +    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 250ea4efb7cb..ca41e4eb33ad 100644
> > --- a/include/linux/firmware/qcom/qcom_scm.h
> > +++ b/include/linux/firmware/qcom/qcom_scm.h
> > @@ -84,6 +84,8 @@ extern bool qcom_scm_pas_supported(u32 peripheral);
> >     extern int qcom_scm_io_readl(phys_addr_t addr, unsigned int *val);
> >   extern int qcom_scm_io_writel(phys_addr_t addr, unsigned int val);
> > +extern int qcom_scm_io_update_field(phys_addr_t addr, unsigned int 
> > mask,
> > +                    unsigned int val);
> >     extern bool qcom_scm_restore_sec_cfg_available(void);
> >   extern int qcom_scm_restore_sec_cfg(u32 device_id, u32 spare);