pmdomain: mediatek: Add support for MTK_SCPD_STRICT_BUS_PROTECTION cap

This adds support for MTK_SCPD_STRICT_BUS_PROTECTION capability. It is a
strict bus protection policy that requires the bus protection to be
disabled before accessing the bus.
This is required by the mt8365, for the MM power domain.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Signed-off-by: Fabien Parent <fparent@baylibre.com>
Signed-off-by: Markus Schneider-Pargmann <msp@baylibre.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Tested-by: Alexandre Mergnat <amergnat@baylibre.com>
Link: https://lore.kernel.org/r/20230918093751.1188668-8-msp@baylibre.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

diff --git a/drivers/pmdomain/mediatek/mtk-pm-domains.c b/drivers/pmdomain/mediatek/mtk-pm-domains.c
index 4bf3a375b7490bf9e030f769354cbb00facfb216..69cdf6ff00b884d5ff5dd2f466cc4f81f81357d2 100644 (file)
--- a/drivers/pmdomain/mediatek/mtk-pm-domains.c
+++ b/drivers/pmdomain/mediatek/mtk-pm-domains.c
@@ -262,9 +262,17 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
        regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_ISO_BIT);
        regmap_set_bits(scpsys->base, pd->data->ctl_offs, PWR_RST_B_BIT);
 
-       ret = clk_bulk_prepare_enable(pd->num_subsys_clks, pd->subsys_clks);
-       if (ret)
-               goto err_pwr_ack;
+       /*
+        * In few Mediatek platforms(e.g. MT6779), the bus protect policy is
+        * stricter, which leads to bus protect release must be prior to bus
+        * access.
+        */
+       if (!MTK_SCPD_CAPS(pd, MTK_SCPD_STRICT_BUS_PROTECTION)) {
+               ret = clk_bulk_prepare_enable(pd->num_subsys_clks,
+                                             pd->subsys_clks);
+               if (ret)
+                       goto err_pwr_ack;
+       }
 
        ret = scpsys_sram_enable(pd);
        if (ret < 0)
@@ -274,12 +282,23 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
        if (ret < 0)
                goto err_disable_sram;
 
+       if (MTK_SCPD_CAPS(pd, MTK_SCPD_STRICT_BUS_PROTECTION)) {
+               ret = clk_bulk_prepare_enable(pd->num_subsys_clks,
+                                             pd->subsys_clks);
+               if (ret)
+                       goto err_enable_bus_protect;
+       }
+
        return 0;
 
+err_enable_bus_protect:
+       scpsys_bus_protect_enable(pd);
 err_disable_sram:
        scpsys_sram_disable(pd);
 err_disable_subsys_clks:
-       clk_bulk_disable_unprepare(pd->num_subsys_clks, pd->subsys_clks);
+       if (!MTK_SCPD_CAPS(pd, MTK_SCPD_STRICT_BUS_PROTECTION))
+               clk_bulk_disable_unprepare(pd->num_subsys_clks,
+                                          pd->subsys_clks);
 err_pwr_ack:
        clk_bulk_disable_unprepare(pd->num_clks, pd->clks);
 err_reg:

diff --git a/drivers/pmdomain/mediatek/mtk-pm-domains.h b/drivers/pmdomain/mediatek/mtk-pm-domains.h
index 17c03321770453c61f1668ceb2b268d36fa9d266..aaba5e6b0536ff020fca15375e80aa658df3699a 100644 (file)
--- a/drivers/pmdomain/mediatek/mtk-pm-domains.h
+++ b/drivers/pmdomain/mediatek/mtk-pm-domains.h
@@ -12,6 +12,7 @@
 #define MTK_SCPD_ALWAYS_ON             BIT(5)
 #define MTK_SCPD_EXT_BUCK_ISO          BIT(6)
 #define MTK_SCPD_HAS_INFRA_NAO         BIT(7)
+#define MTK_SCPD_STRICT_BUS_PROTECTION BIT(8)
 #define MTK_SCPD_CAPS(_scpd, _x)       ((_scpd)->data->caps & (_x))
 
 #define SPM_VDE_PWR_CON                        0x0210
@@ -107,7 +108,7 @@ struct scpsys_domain_data {
        u32 sram_pdn_ack_bits;
        int ext_buck_iso_offs;
        u32 ext_buck_iso_mask;
-       u8 caps;
+       u16 caps;
        const struct scpsys_bus_prot_data bp_cfg[SPM_MAX_BUS_PROT_DATA];
        int pwr_sta_offs;
        int pwr_sta2nd_offs;