pmdomain: mediatek: Add support for secure HWCCF infra power on

Some SoCs, like the MediaTek Dimensity 9400 (MT6991), have granular
power controls and will disable power to the infracfg to save power
when the platform is in deeper sleep states (or when no IP in the
the infracfg macro-block is in use).

These chips also cannot control the infracfg power states directly
via AP register writes as those are protected by the secure world.

Add a new MTK_SCPD_INFRA_PWR_CTL cap and, if present, make a call
to the secure world to poweron the infracfg block, as the HWV IP
resides in there, when executing HWV domains power sequences.

Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>

drivers/pmdomain/mediatek/mtk-pm-domains.c

@@ -15,6 +15,7 @@
 #include <linux/regmap.h>
 #include <linux/regulator/consumer.h>
 #include <linux/soc/mediatek/infracfg.h>
+#include <linux/soc/mediatek/mtk_sip_svc.h>
 
 #include "mt6735-pm-domains.h"
 #include "mt6795-pm-domains.h"
@@ -51,6 +52,8 @@
 #define PWR_RTFF_SAVE_FLAG		BIT(27)
 #define PWR_RTFF_UFS_CLK_DIS		BIT(28)
 
+#define MTK_SIP_KERNEL_HWCCF_CONTROL	MTK_SIP_SMC_CMD(0x540)
+
 struct scpsys_domain {
 	struct generic_pm_domain genpd;
 	const struct scpsys_domain_data *data;
@@ -116,6 +119,15 @@ static bool scpsys_hwv_domain_is_enable_done(struct scpsys_domain *pd)
 	return (val[0] & mask) && (val[1] & mask) && !(val[2] & mask);
 }
 
+static int scpsys_sec_infra_power_on(bool on)
+{
+	struct arm_smccc_res res;
+	unsigned long cmd = on ? 1 : 0;
+
+	arm_smccc_smc(MTK_SIP_KERNEL_HWCCF_CONTROL, cmd, 0, 0, 0, 0, 0, 0, &res);
+	return res.a0;
+}
+
 static int scpsys_sram_enable(struct scpsys_domain *pd)
 {
 	u32 expected_ack, pdn_ack = pd->data->sram_pdn_ack_bits;
@@ -291,9 +303,15 @@ static int scpsys_hwv_power_on(struct generic_pm_domain *genpd)
 	u32 val;
 	int ret;
 
+	if (MTK_SCPD_CAPS(pd, MTK_SCPD_INFRA_PWR_CTL)) {
+		ret = scpsys_sec_infra_power_on(true);
+		if (ret)
+			return ret;
+	}
+
 	ret = scpsys_regulator_enable(pd->supply);
 	if (ret)
-		return ret;
+		goto err_infra;
 
 	ret = clk_bulk_prepare_enable(pd->num_clks, pd->clks);
 	if (ret)
@@ -344,6 +362,9 @@ static int scpsys_hwv_power_on(struct generic_pm_domain *genpd)
 	/* It's done! Disable the HWV low power subsystem clocks */
 	clk_bulk_disable_unprepare(pd->num_subsys_clks, pd->subsys_clks);
 
+	if (MTK_SCPD_CAPS(pd, MTK_SCPD_INFRA_PWR_CTL))
+		scpsys_sec_infra_power_on(false);
+
 	return 0;
 
 err_disable_subsys_clks:
@@ -352,6 +373,9 @@ err_disable_clks:
 	clk_bulk_disable_unprepare(pd->num_clks, pd->clks);
 err_reg:
 	scpsys_regulator_disable(pd->supply);
+err_infra:
+	if (MTK_SCPD_CAPS(pd, MTK_SCPD_INFRA_PWR_CTL))
+		scpsys_sec_infra_power_on(false);
 	return ret;
 };
 
@@ -363,9 +387,15 @@ static int scpsys_hwv_power_off(struct generic_pm_domain *genpd)
 	u32 val;
 	int ret;
 
+	if (MTK_SCPD_CAPS(pd, MTK_SCPD_INFRA_PWR_CTL)) {
+		ret = scpsys_sec_infra_power_on(true);
+		if (ret)
+			return ret;
+	}
+
 	ret = clk_bulk_prepare_enable(pd->num_subsys_clks, pd->subsys_clks);
 	if (ret)
-		return ret;
+		goto err_infra;
 
 	/* Make sure the HW Voter is idle and able to accept commands */
 	ret = regmap_read_poll_timeout_atomic(scpsys->base, hwv->done, val,
@@ -407,10 +437,16 @@ static int scpsys_hwv_power_off(struct generic_pm_domain *genpd)
 
 	scpsys_regulator_disable(pd->supply);
 
+	if (MTK_SCPD_CAPS(pd, MTK_SCPD_INFRA_PWR_CTL))
+		scpsys_sec_infra_power_on(false);
+
 	return 0;
 
 err_disable_subsys_clks:
 	clk_bulk_disable_unprepare(pd->num_subsys_clks, pd->subsys_clks);
+err_infra:
+	if (MTK_SCPD_CAPS(pd, MTK_SCPD_INFRA_PWR_CTL))
+		scpsys_sec_infra_power_on(false);
 	return ret;
 };
 

drivers/pmdomain/mediatek/mtk-pm-domains.h

@@ -16,6 +16,7 @@
 #define MTK_SCPD_SRAM_PDN_INVERTED	BIT(9)
 #define MTK_SCPD_MODEM_PWRSEQ		BIT(10)
 #define MTK_SCPD_SKIP_RESET_B		BIT(11)
+#define MTK_SCPD_INFRA_PWR_CTL		BIT(12)
 #define MTK_SCPD_CAPS(_scpd, _x)	((_scpd)->data ?		\
 					 (_scpd)->data->caps & (_x) :	\
 					 (_scpd)->hwv_data->caps & (_x))