linux-kernel - Re: [PATCH] firmware: qcom_scm: modify qcom_scm_set_download

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Date:   Thu, 2 Feb 2023 12:12:35 +0200
From:   Dmitry Baryshkov <dmitry.baryshkov@...aro.org>
To:     Mukesh Ojha <quic_mojha@...cinc.com>
Cc:     agross@...nel.org, andersson@...nel.org, konrad.dybcio@...aro.org,
        linux-arm-msm@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: Re: [PATCH] firmware: qcom_scm: modify qcom_scm_set_download_mode()

On Tue, 24 Jan 2023 at 14:19, Mukesh Ojha <quic_mojha@...cinc.com> wrote:
>
> Modify qcom_scm_set_download_mode() such that it can support
> multiple modes. There is no functional change with this change.

Please describe usecases for such a change. Without them it's just an
unused complication.

>
> Signed-off-by: Mukesh Ojha <quic_mojha@...cinc.com>
> ---
>  drivers/firmware/qcom_scm.c | 17 ++++++++---------
>  include/linux/qcom_scm.h    |  5 +++++
>  2 files changed, 13 insertions(+), 9 deletions(-)
>
> diff --git a/drivers/firmware/qcom_scm.c b/drivers/firmware/qcom_scm.c
> index cdbfe54..712bb03 100644
> --- a/drivers/firmware/qcom_scm.c
> +++ b/drivers/firmware/qcom_scm.c
> @@ -400,22 +400,22 @@ int qcom_scm_set_remote_state(u32 state, u32 id)
>  }
>  EXPORT_SYMBOL(qcom_scm_set_remote_state);
>
> -static int __qcom_scm_set_dload_mode(struct device *dev, bool enable)
> +static int __qcom_scm_set_dload_mode(struct device *dev, enum qcom_download_mode mode)
>  {
>         struct qcom_scm_desc desc = {
>                 .svc = QCOM_SCM_SVC_BOOT,
>                 .cmd = QCOM_SCM_BOOT_SET_DLOAD_MODE,
>                 .arginfo = QCOM_SCM_ARGS(2),
> -               .args[0] = QCOM_SCM_BOOT_SET_DLOAD_MODE,
> +               .args[0] = mode,
>                 .owner = ARM_SMCCC_OWNER_SIP,
>         };
>
> -       desc.args[1] = enable ? QCOM_SCM_BOOT_SET_DLOAD_MODE : 0;
> +       desc.args[1] = mode;
>
>         return qcom_scm_call_atomic(__scm->dev, &desc, NULL);
>  }
>
> -static void qcom_scm_set_download_mode(bool enable)
> +static void qcom_scm_set_download_mode(enum qcom_download_mode mode)
>  {
>         bool avail;
>         int ret = 0;
> @@ -424,10 +424,9 @@ static void qcom_scm_set_download_mode(bool enable)
>                                              QCOM_SCM_SVC_BOOT,
>                                              QCOM_SCM_BOOT_SET_DLOAD_MODE);
>         if (avail) {
> -               ret = __qcom_scm_set_dload_mode(__scm->dev, enable);
> +               ret = __qcom_scm_set_dload_mode(__scm->dev, mode);
>         } else if (__scm->dload_mode_addr) {
> -               ret = qcom_scm_io_writel(__scm->dload_mode_addr,
> -                               enable ? QCOM_SCM_BOOT_SET_DLOAD_MODE : 0);
> +               ret = qcom_scm_io_writel(__scm->dload_mode_addr, mode);
>         } else {
>                 dev_err(__scm->dev,
>                         "No available mechanism for setting download mode\n");
> @@ -1410,7 +1409,7 @@ static int qcom_scm_probe(struct platform_device *pdev)
>          * disabled below by a clean shutdown/reboot.
>          */
>         if (download_mode)
> -               qcom_scm_set_download_mode(true);
> +               qcom_scm_set_download_mode(QCOM_DOWNLOAD_FULLDUMP);
>
>         return 0;
>  }
> @@ -1419,7 +1418,7 @@ static void qcom_scm_shutdown(struct platform_device *pdev)
>  {
>         /* Clean shutdown, disable download mode to allow normal restart */
>         if (download_mode)
> -               qcom_scm_set_download_mode(false);
> +               qcom_scm_set_download_mode(QCOM_DOWNLOAD_NODUMP);
>  }
>
>  static const struct of_device_id qcom_scm_dt_match[] = {
> diff --git a/include/linux/qcom_scm.h b/include/linux/qcom_scm.h
> index f833564..f9bc84e 100644
> --- a/include/linux/qcom_scm.h
> +++ b/include/linux/qcom_scm.h
> @@ -14,6 +14,11 @@
>  #define QCOM_SCM_CPU_PWR_DOWN_L2_OFF   0x1
>  #define QCOM_SCM_HDCP_MAX_REQ_CNT      5
>
> +enum qcom_download_mode {
> +       QCOM_DOWNLOAD_NODUMP    = 0x00,
> +       QCOM_DOWNLOAD_FULLDUMP  = 0x10,
> +};
> +
>  struct qcom_scm_hdcp_req {
>         u32 addr;
>         u32 val;
> --
> 2.7.4
>


-- 
With best wishes
Dmitry