soc: mediatek: Fix random hang up issue while kernel init

In kernel late init, it turns off all unused clocks, which
needs to access subsystem registers such as VENC and VENC_LT.

Accessing MT8173 VENC registers needs two top clocks, mm_sel and
venc_sel. Accessing VENC_LT registers needs mm_sel and venclt_sel.
So we need to keep these clocks on before accessing their registers.

This patch keeps venc_sel / venclt_sel clock on when
VENC / VENC_LT's power is on, to prevent system hang up while
accessing its registeres.

Signed-off-by: James Liao <jamesjj.liao@mediatek.com>
Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>

1 files changed, 44 insertions, 23 deletions

diff --git a/drivers/soc/mediatek/mtk-scpsys.c b/drivers/soc/mediatek/mtk-scpsys.c
index 55ab08ffc010..4d4203c896c4 100644
--- a/drivers/soc/mediatek/mtk-scpsys.c
+++ b/drivers/soc/mediatek/mtk-scpsys.c
@@ -54,12 +54,16 @@
 #define PWR_STATUS_USB                  BIT(25)
 
 enum clk_id {
+        MT8173_CLK_NONE,
         MT8173_CLK_MM,
         MT8173_CLK_MFG,
-        MT8173_CLK_NONE,
-        MT8173_CLK_MAX = MT8173_CLK_NONE,
+        MT8173_CLK_VENC,
+        MT8173_CLK_VENC_LT,
+        MT8173_CLK_MAX,
 };
 
+#define MAX_CLKS        2
+
 struct scp_domain_data {
         const char *name;
         u32 sta_mask;
@@ -67,7 +71,7 @@ struct scp_domain_data {
         u32 sram_pdn_bits;
         u32 sram_pdn_ack_bits;
         u32 bus_prot_mask;
-        enum clk_id clk_id;
+        enum clk_id clk_id[MAX_CLKS];
         bool active_wakeup;
 };
 
@@ -78,7 +82,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
                 .ctl_offs = SPM_VDE_PWR_CON,
                 .sram_pdn_bits = GENMASK(11, 8),
                 .sram_pdn_ack_bits = GENMASK(12, 12),
-                .clk_id = MT8173_CLK_MM,
+                .clk_id = {MT8173_CLK_MM},
         },
         [MT8173_POWER_DOMAIN_VENC] = {
                 .name = "venc",
@@ -86,7 +90,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
                 .ctl_offs = SPM_VEN_PWR_CON,
                 .sram_pdn_bits = GENMASK(11, 8),
                 .sram_pdn_ack_bits = GENMASK(15, 12),
-                .clk_id = MT8173_CLK_MM,
+                .clk_id = {MT8173_CLK_MM, MT8173_CLK_VENC},
         },
         [MT8173_POWER_DOMAIN_ISP] = {
                 .name = "isp",
@@ -94,7 +98,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
                 .ctl_offs = SPM_ISP_PWR_CON,
                 .sram_pdn_bits = GENMASK(11, 8),
                 .sram_pdn_ack_bits = GENMASK(13, 12),
-                .clk_id = MT8173_CLK_MM,
+                .clk_id = {MT8173_CLK_MM},
         },
         [MT8173_POWER_DOMAIN_MM] = {
                 .name = "mm",
@@ -102,7 +106,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
                 .ctl_offs = SPM_DIS_PWR_CON,
                 .sram_pdn_bits = GENMASK(11, 8),
                 .sram_pdn_ack_bits = GENMASK(12, 12),
-                .clk_id = MT8173_CLK_MM,
+                .clk_id = {MT8173_CLK_MM},
                 .bus_prot_mask = MT8173_TOP_AXI_PROT_EN_MM_M0 |
                         MT8173_TOP_AXI_PROT_EN_MM_M1,
         },
@@ -112,7 +116,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
                 .ctl_offs = SPM_VEN2_PWR_CON,
                 .sram_pdn_bits = GENMASK(11, 8),
                 .sram_pdn_ack_bits = GENMASK(15, 12),
-                .clk_id = MT8173_CLK_MM,
+                .clk_id = {MT8173_CLK_MM, MT8173_CLK_VENC_LT},
         },
         [MT8173_POWER_DOMAIN_AUDIO] = {
                 .name = "audio",
@@ -120,7 +124,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
                 .ctl_offs = SPM_AUDIO_PWR_CON,
                 .sram_pdn_bits = GENMASK(11, 8),
                 .sram_pdn_ack_bits = GENMASK(15, 12),
-                .clk_id = MT8173_CLK_NONE,
+                .clk_id = {MT8173_CLK_NONE},
         },
         [MT8173_POWER_DOMAIN_USB] = {
                 .name = "usb",
@@ -128,7 +132,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
                 .ctl_offs = SPM_USB_PWR_CON,
                 .sram_pdn_bits = GENMASK(11, 8),
                 .sram_pdn_ack_bits = GENMASK(15, 12),
-                .clk_id = MT8173_CLK_NONE,
+                .clk_id = {MT8173_CLK_NONE},
                 .active_wakeup = true,
         },
         [MT8173_POWER_DOMAIN_MFG_ASYNC] = {
@@ -137,7 +141,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
                 .ctl_offs = SPM_MFG_ASYNC_PWR_CON,
                 .sram_pdn_bits = GENMASK(11, 8),
                 .sram_pdn_ack_bits = 0,
-                .clk_id = MT8173_CLK_MFG,
+                .clk_id = {MT8173_CLK_MFG},
         },
         [MT8173_POWER_DOMAIN_MFG_2D] = {
                 .name = "mfg_2d",
@@ -145,7 +149,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
                 .ctl_offs = SPM_MFG_2D_PWR_CON,
                 .sram_pdn_bits = GENMASK(11, 8),
                 .sram_pdn_ack_bits = GENMASK(13, 12),
-                .clk_id = MT8173_CLK_NONE,
+                .clk_id = {MT8173_CLK_NONE},
         },
         [MT8173_POWER_DOMAIN_MFG] = {
                 .name = "mfg",
@@ -153,7 +157,7 @@ static const struct scp_domain_data scp_domain_data[] __initconst = {
                 .ctl_offs = SPM_MFG_PWR_CON,
                 .sram_pdn_bits = GENMASK(13, 8),
                 .sram_pdn_ack_bits = GENMASK(21, 16),
-                .clk_id = MT8173_CLK_NONE,
+                .clk_id = {MT8173_CLK_NONE},
                 .bus_prot_mask = MT8173_TOP_AXI_PROT_EN_MFG_S |
                         MT8173_TOP_AXI_PROT_EN_MFG_M0 |
                         MT8173_TOP_AXI_PROT_EN_MFG_M1 |
@@ -168,7 +172,7 @@ struct scp;
 struct scp_domain {
         struct generic_pm_domain genpd;
         struct scp *scp;
-        struct clk *clk;
+        struct clk *clk[MAX_CLKS];
         u32 sta_mask;
         void __iomem *ctl_addr;
         u32 sram_pdn_bits;
@@ -215,11 +219,16 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
         u32 sram_pdn_ack = scpd->sram_pdn_ack_bits;
         u32 val;
         int ret;
+        int i;
+
+        for (i = 0; i < MAX_CLKS && scpd->clk[i]; i++) {
+                ret = clk_prepare_enable(scpd->clk[i]);
+                if (ret) {
+                        for (--i; i >= 0; i--)
+                                clk_disable_unprepare(scpd->clk[i]);
 
-        if (scpd->clk) {
-                ret = clk_prepare_enable(scpd->clk);
-                if (ret)
                         goto err_clk;
+                }
         }
 
         val = readl(ctl_addr);
@@ -285,7 +294,10 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
         return 0;
 
 err_pwr_ack:
-        clk_disable_unprepare(scpd->clk);
+        for (i = MAX_CLKS - 1; i >= 0; i--) {
+                if (scpd->clk[i])
+                        clk_disable_unprepare(scpd->clk[i]);
+        }
 err_clk:
         dev_err(scp->dev, "Failed to power on domain %s\n", genpd->name);
 
@@ -302,6 +314,7 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
         u32 pdn_ack = scpd->sram_pdn_ack_bits;
         u32 val;
         int ret;
+        int i;
 
         if (scpd->bus_prot_mask) {
                 ret = mtk_infracfg_set_bus_protection(scp->infracfg,
@@ -363,8 +376,8 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
                         expired = true;
         }
 
-        if (scpd->clk)
-                clk_disable_unprepare(scpd->clk);
+        for (i = 0; i < MAX_CLKS && scpd->clk[i]; i++)
+                clk_disable_unprepare(scpd->clk[i]);
 
         return 0;
 
@@ -389,7 +402,7 @@ static int __init scpsys_probe(struct platform_device *pdev)
 {
         struct genpd_onecell_data *pd_data;
         struct resource *res;
-        int i, ret;
+        int i, j, ret;
         struct scp *scp;
         struct clk *clk[MT8173_CLK_MAX];
 
@@ -419,6 +432,14 @@ static int __init scpsys_probe(struct platform_device *pdev)
         if (IS_ERR(clk[MT8173_CLK_MFG]))
                 return PTR_ERR(clk[MT8173_CLK_MFG]);
 
+        clk[MT8173_CLK_VENC] = devm_clk_get(&pdev->dev, "venc");
+        if (IS_ERR(clk[MT8173_CLK_VENC]))
+                return PTR_ERR(clk[MT8173_CLK_VENC]);
+
+        clk[MT8173_CLK_VENC_LT] = devm_clk_get(&pdev->dev, "venc_lt");
+        if (IS_ERR(clk[MT8173_CLK_VENC_LT]))
+                return PTR_ERR(clk[MT8173_CLK_VENC_LT]);
+
         scp->infracfg = syscon_regmap_lookup_by_phandle(pdev->dev.of_node,
                         "infracfg");
         if (IS_ERR(scp->infracfg)) {
@@ -443,8 +464,8 @@ static int __init scpsys_probe(struct platform_device *pdev)
                 scpd->sram_pdn_ack_bits = data->sram_pdn_ack_bits;
                 scpd->bus_prot_mask = data->bus_prot_mask;
                 scpd->active_wakeup = data->active_wakeup;
-                if (data->clk_id != MT8173_CLK_NONE)
-                        scpd->clk = clk[data->clk_id];
+                for (j = 0; j < MAX_CLKS && data->clk_id[j]; j++)
+                        scpd->clk[j] = clk[data->clk_id[j]];
 
                 genpd->name = data->name;
                 genpd->power_off = scpsys_power_off;