soc: mediatek: extend bus protection API

MT2712 add "set/clear" bus control register to each control register set
instead of providing only one "enable" control register, we could avoid
the read-modify-write racing by declaring "bus_prot_reg_update" as "false"
in scp_soc_data or declaring as "true" to use the legacy update method.
By improving the mtk-infracfg bus protection implementation to
support set/clear bus protection control method by IC configuration.

Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

diff --git a/drivers/soc/mediatek/mtk-infracfg.c b/drivers/soc/mediatek/mtk-infracfg.c
index dba3055a949310843f34eceafd8cf5e9662eaf8c..8c310de01e93744d182055fee11b38ba63953605 100644 (file)
--- a/drivers/soc/mediatek/mtk-infracfg.c
+++ b/drivers/soc/mediatek/mtk-infracfg.c
@@ -19,23 +19,33 @@
 
 #define INFRA_TOPAXI_PROTECTEN         0x0220
 #define INFRA_TOPAXI_PROTECTSTA1       0x0228
+#define INFRA_TOPAXI_PROTECTEN_SET     0x0260
+#define INFRA_TOPAXI_PROTECTEN_CLR     0x0264
 
 /**
  * mtk_infracfg_set_bus_protection - enable bus protection
  * @regmap: The infracfg regmap
  * @mask: The mask containing the protection bits to be enabled.
+ * @reg_update: The boolean flag determines to set the protection bits
+ *              by regmap_update_bits with enable register(PROTECTEN) or
+ *              by regmap_write with set register(PROTECTEN_SET).
  *
  * This function enables the bus protection bits for disabled power
  * domains so that the system does not hang when some unit accesses the
  * bus while in power down.
  */
-int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask)
+int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
+               bool reg_update)
 {
        unsigned long expired;
        u32 val;
        int ret;
 
-       regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask, mask);
+       if (reg_update)
+               regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask,
+                               mask);
+       else
+               regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_SET, mask);
 
        expired = jiffies + HZ;
 
@@ -59,16 +69,24 @@ int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask)
  * mtk_infracfg_clear_bus_protection - disable bus protection
  * @regmap: The infracfg regmap
  * @mask: The mask containing the protection bits to be disabled.
+ * @reg_update: The boolean flag determines to clear the protection bits
+ *              by regmap_update_bits with enable register(PROTECTEN) or
+ *              by regmap_write with clear register(PROTECTEN_CLR).
  *
  * This function disables the bus protection bits previously enabled with
  * mtk_infracfg_set_bus_protection.
  */
-int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask)
+
+int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
+               bool reg_update)
 {
        unsigned long expired;
        int ret;
 
-       regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask, 0);
+       if (reg_update)
+               regmap_update_bits(infracfg, INFRA_TOPAXI_PROTECTEN, mask, 0);
+       else
+               regmap_write(infracfg, INFRA_TOPAXI_PROTECTEN_CLR, mask);
 
        expired = jiffies + HZ;
 

diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
index e570b6af2e6ffbddccf1fe76075375d4e39e3e0c..4c484b1d2f3019a79e8ea516ff2e3d34998dae18 100644 (file)
--- a/drivers/soc/mediatek/mtk-scpsys.c
+++ b/drivers/soc/mediatek/mtk-scpsys.c
@@ -134,6 +134,7 @@ struct scp {
        void __iomem *base;
        struct regmap *infracfg;
        struct scp_ctrl_reg ctrl_reg;
+       bool bus_prot_reg_update;
 };
 
 struct scp_subdomain {
@@ -147,6 +148,7 @@ struct scp_soc_data {
        const struct scp_subdomain *subdomains;
        int num_subdomains;
        const struct scp_ctrl_reg regs;
+       bool bus_prot_reg_update;
 };
 
 static int scpsys_domain_is_on(struct scp_domain *scpd)
@@ -254,7 +256,8 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
 
        if (scpd->data->bus_prot_mask) {
                ret = mtk_infracfg_clear_bus_protection(scp->infracfg,
-                               scpd->data->bus_prot_mask);
+                               scpd->data->bus_prot_mask,
+                               scp->bus_prot_reg_update);
                if (ret)
                        goto err_pwr_ack;
        }
@@ -289,7 +292,8 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
 
        if (scpd->data->bus_prot_mask) {
                ret = mtk_infracfg_set_bus_protection(scp->infracfg,
-                               scpd->data->bus_prot_mask);
+                               scpd->data->bus_prot_mask,
+                               scp->bus_prot_reg_update);
                if (ret)
                        goto out;
        }
@@ -371,7 +375,8 @@ static void init_clks(struct platform_device *pdev, struct clk **clk)
 
 static struct scp *init_scp(struct platform_device *pdev,
                        const struct scp_domain_data *scp_domain_data, int num,
-                       const struct scp_ctrl_reg *scp_ctrl_reg)
+                       const struct scp_ctrl_reg *scp_ctrl_reg,
+                       bool bus_prot_reg_update)
 {
        struct genpd_onecell_data *pd_data;
        struct resource *res;
@@ -386,6 +391,8 @@ static struct scp *init_scp(struct platform_device *pdev,
        scp->ctrl_reg.pwr_sta_offs = scp_ctrl_reg->pwr_sta_offs;
        scp->ctrl_reg.pwr_sta2nd_offs = scp_ctrl_reg->pwr_sta2nd_offs;
 
+       scp->bus_prot_reg_update = bus_prot_reg_update;
+
        scp->dev = &pdev->dev;
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
@@ -806,7 +813,8 @@ static const struct scp_soc_data mt2701_data = {
        .regs = {
                .pwr_sta_offs = SPM_PWR_STATUS,
                .pwr_sta2nd_offs = SPM_PWR_STATUS_2ND
-       }
+       },
+       .bus_prot_reg_update = true,
 };
 
 static const struct scp_soc_data mt6797_data = {
@@ -817,7 +825,8 @@ static const struct scp_soc_data mt6797_data = {
        .regs = {
                .pwr_sta_offs = SPM_PWR_STATUS_MT6797,
                .pwr_sta2nd_offs = SPM_PWR_STATUS_2ND_MT6797
-       }
+       },
+       .bus_prot_reg_update = true,
 };
 
 static const struct scp_soc_data mt7622_data = {
@@ -826,7 +835,8 @@ static const struct scp_soc_data mt7622_data = {
        .regs = {
                .pwr_sta_offs = SPM_PWR_STATUS,
                .pwr_sta2nd_offs = SPM_PWR_STATUS_2ND
-       }
+       },
+       .bus_prot_reg_update = true,
 };
 
 static const struct scp_soc_data mt8173_data = {
@@ -837,7 +847,8 @@ static const struct scp_soc_data mt8173_data = {
        .regs = {
                .pwr_sta_offs = SPM_PWR_STATUS,
                .pwr_sta2nd_offs = SPM_PWR_STATUS_2ND
-       }
+       },
+       .bus_prot_reg_update = true,
 };
 
 /*
@@ -874,7 +885,8 @@ static int scpsys_probe(struct platform_device *pdev)
        match = of_match_device(of_scpsys_match_tbl, &pdev->dev);
        soc = (const struct scp_soc_data *)match->data;
 
-       scp = init_scp(pdev, soc->domains, soc->num_domains, &soc->regs);
+       scp = init_scp(pdev, soc->domains, soc->num_domains, &soc->regs,
+                       soc->bus_prot_reg_update);
        if (IS_ERR(scp))
                return PTR_ERR(scp);
 

diff --git a/include/linux/soc/mediatek/infracfg.h b/include/linux/soc/mediatek/infracfg.h
index e8d9f0d52933193740404601be224aee6b10b0da..b0a507d356ef04465a2c390a30f58ddb0853756d 100644 (file)
--- a/include/linux/soc/mediatek/infracfg.h
+++ b/include/linux/soc/mediatek/infracfg.h
@@ -28,7 +28,8 @@
 #define MT7622_TOP_AXI_PROT_EN_WB              (BIT(2) | BIT(6) | \
                                                 BIT(7) | BIT(8))
 
-int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask);
-int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask);
-
+int mtk_infracfg_set_bus_protection(struct regmap *infracfg, u32 mask,
+               bool reg_update);
+int mtk_infracfg_clear_bus_protection(struct regmap *infracfg, u32 mask,
+               bool reg_update);
 #endif /* __SOC_MEDIATEK_INFRACFG_H */