Re: [PATCH v2 2/4] soc: mediatek: pm-domains: Add default power off flag

[Matthias Brugger]

On 22/10/2020 14:47, Weiyi Lu wrote:

For some power domain, like conn on MT8192, it should be default OFF.
Because the power on/off control relies the function of connectivity chip
and its firmware. And if project choose other chip vendor solution,
those necessary connectivity functions will not provided.

Signed-off-by: Weiyi Lu <weiyi...@mediatek.com>
---
  drivers/soc/mediatek/mtk-pm-domains.c | 23 +++++++++++++++++------
  1 file changed, 17 insertions(+), 6 deletions(-)

diff --git a/drivers/soc/mediatek/mtk-pm-domains.c 
b/drivers/soc/mediatek/mtk-pm-domains.c
index b7ccf94..50a7ae1 100644
--- a/drivers/soc/mediatek/mtk-pm-domains.c
+++ b/drivers/soc/mediatek/mtk-pm-domains.c
@@ -24,6 +24,7 @@
  #define MTK_SCPD_ACTIVE_WAKEUP                BIT(0)
  #define MTK_SCPD_FWAIT_SRAM           BIT(1)
  #define MTK_SCPD_SRAM_ISO             BIT(2)
+#define MTK_SCPD_KEEP_DEFAULT_OFF      BIT(3)
  #define MTK_SCPD_CAPS(_scpd, _x)      ((_scpd)->data->caps & (_x))

#define SPM_VDE_PWR_CON 0x0210

@@ -506,17 +507,26 @@ static int scpsys_add_one_domain(struct scpsys *scpsys, 
struct device_node *node
         * software.  The unused domains will be switched off during
         * late_init time.
         */
-       ret = scpsys_power_on(&pd->genpd);
-       if (ret < 0) {
-               dev_err_probe(scpsys->dev, ret, "failed to power on domain 
%pOFN\n", node);
-               goto err_unprepare_clocks;
+       if (MTK_SCPD_CAPS(pd, MTK_SCPD_KEEP_DEFAULT_OFF)) {
+               if (scpsys_domain_is_on(pd))
+                       dev_warn(scpsys->dev,
+                                "A default off power domain %pOFN has been 
ON\n", node);
+       } else {
+               ret = scpsys_power_on(&pd->genpd);
+               if (ret < 0) {
+                       dev_err_probe(scpsys->dev, ret, "failed to power on domain 
%pOFN\n", node);
+                       goto err_unprepare_clocks;
+               }
        }

pd->genpd.name = node->name;

        pd->genpd.power_off = scpsys_power_off;
        pd->genpd.power_on = scpsys_power_on;

- pm_genpd_init(&pd->genpd, NULL, false);

+       if (MTK_SCPD_CAPS(pd, MTK_SCPD_KEEP_DEFAULT_OFF))
+               pm_genpd_init(&pd->genpd, NULL, true);
+       else
+               pm_genpd_init(&pd->genpd, NULL, false);

scpsys->domains[id] = &pd->genpd;

        return 0;
@@ -603,7 +613,8 @@ static void scpsys_remove_one_domain(struct scpsys_domain 
*pd)
                        "failed to remove domain '%s' : %d - state may be 
inconsistent\n",
                        pd->genpd.name, ret);

- scpsys_power_off(&pd->genpd);

+       if (!MTK_SCPD_CAPS(pd, MTK_SCPD_KEEP_DEFAULT_OFF))
+               scpsys_power_off(&pd->genpd);

Is that really needed? Turning the domain off when it's already off shouldn't 
hurt.

Regards,
Matthias