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From:   Hsin-Yi Wang <hsinyi@chromium.org>
To:     Matthias Brugger <matthias.bgg@gmail.com>
Cc:     linux-arm-kernel@lists.infradead.org,
        linux-mediatek@lists.infradead.org, linux-kernel@vger.kernel.org,
        Rob Herring <robh+dt@kernel.org>,
        Enric Balletbo i Serra <enric.balletbo@collabora.com>,
        chun-jie.chen@mediatek.corp-partner.google.com,
        Yong Wu <yong.wu@mediatek.com>
Subject: [PATCH 1/3] soc: mtk-pm-domains: Fix the clock prepared issue
Date:   Mon, 31 May 2021 12:35:00 +0800
Message-Id: <20210531043502.2702645-1-hsinyi@chromium.org>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

From: Weiyi Lu <weiyi.lu@mediatek.com>

In this new power domain driver, when adding one power domain
it will prepare the depenedent clocks at the same.
So we only do clk_bulk_enable/disable control during power ON/OFF.
When system suspend, the pm runtime framework will forcely power off
power domains. However, the dependent clocks are disabled but kept
preapred.

In MediaTek clock drivers, PLL would be turned ON when we do
clk_bulk_prepare control.

Clock hierarchy:
PLL -->
       DIV_CK -->
                 CLK_MUX
                 (may be dependent clocks)
                         -->
                             SUBSYS_CG
                             (may be dependent clocks)

It will lead some unexpected clock states during system suspend.
This patch will fix by doing prepare_enable/disable_unprepare on
dependent clocks at the same time while we are going to power on/off
any power domain.

Signed-off-by: Weiyi Lu <weiyi.lu@mediatek.com>
Signed-off-by: Hsin-Yi Wang <hsinyi@chromium.org>
---
 drivers/soc/mediatek/mtk-pm-domains.c | 31 +++++++--------------------
 1 file changed, 8 insertions(+), 23 deletions(-)

diff --git a/drivers/soc/mediatek/mtk-pm-domains.c b/drivers/soc/mediatek/mtk-pm-domains.c
index 0af00efa0ef8..536d8c64b2b4 100644
--- a/drivers/soc/mediatek/mtk-pm-domains.c
+++ b/drivers/soc/mediatek/mtk-pm-domains.c
@@ -211,7 +211,7 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
 	if (ret)
 		return ret;
 
-	ret = clk_bulk_enable(pd->num_clks, pd->clks);
+	ret = clk_bulk_prepare_enable(pd->num_clks, pd->clks);
 	if (ret)
 		goto err_reg;
 
@@ -229,7 +229,7 @@ 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_enable(pd->num_subsys_clks, pd->subsys_clks);
+	ret = clk_bulk_prepare_enable(pd->num_subsys_clks, pd->subsys_clks);
 	if (ret)
 		goto err_pwr_ack;
 
@@ -246,9 +246,9 @@ static int scpsys_power_on(struct generic_pm_domain *genpd)
 err_disable_sram:
 	scpsys_sram_disable(pd);
 err_disable_subsys_clks:
-	clk_bulk_disable(pd->num_subsys_clks, pd->subsys_clks);
+	clk_bulk_disable_unprepare(pd->num_subsys_clks, pd->subsys_clks);
 err_pwr_ack:
-	clk_bulk_disable(pd->num_clks, pd->clks);
+	clk_bulk_disable_unprepare(pd->num_clks, pd->clks);
 err_reg:
 	scpsys_regulator_disable(pd->supply);
 	return ret;
@@ -269,7 +269,7 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
 	if (ret < 0)
 		return ret;
 
-	clk_bulk_disable(pd->num_subsys_clks, pd->subsys_clks);
+	clk_bulk_disable_unprepare(pd->num_subsys_clks, pd->subsys_clks);
 
 	/* subsys power off */
 	regmap_clear_bits(scpsys->base, pd->data->ctl_offs, PWR_RST_B_BIT);
@@ -284,7 +284,7 @@ static int scpsys_power_off(struct generic_pm_domain *genpd)
 	if (ret < 0)
 		return ret;
 
-	clk_bulk_disable(pd->num_clks, pd->clks);
+	clk_bulk_disable_unprepare(pd->num_clks, pd->clks);
 
 	scpsys_regulator_disable(pd->supply);
 
@@ -405,14 +405,6 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no
 		pd->subsys_clks[i].clk = clk;
 	}
 
-	ret = clk_bulk_prepare(pd->num_clks, pd->clks);
-	if (ret)
-		goto err_put_subsys_clocks;
-
-	ret = clk_bulk_prepare(pd->num_subsys_clks, pd->subsys_clks);
-	if (ret)
-		goto err_unprepare_clocks;
-
 	/*
 	 * Initially turn on all domains to make the domains usable
 	 * with !CONFIG_PM and to get the hardware in sync with the
@@ -427,7 +419,7 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no
 		ret = scpsys_power_on(&pd->genpd);
 		if (ret < 0) {
 			dev_err(scpsys->dev, "%pOF: failed to power on domain: %d\n", node, ret);
-			goto err_unprepare_clocks;
+			goto err_put_subsys_clocks;
 		}
 	}
 
@@ -435,7 +427,7 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no
 		ret = -EINVAL;
 		dev_err(scpsys->dev,
 			"power domain with id %d already exists, check your device-tree\n", id);
-		goto err_unprepare_subsys_clocks;
+		goto err_put_subsys_clocks;
 	}
 
 	if (!pd->data->name)
@@ -455,10 +447,6 @@ generic_pm_domain *scpsys_add_one_domain(struct scpsys *scpsys, struct device_no
 
 	return scpsys->pd_data.domains[id];
 
-err_unprepare_subsys_clocks:
-	clk_bulk_unprepare(pd->num_subsys_clks, pd->subsys_clks);
-err_unprepare_clocks:
-	clk_bulk_unprepare(pd->num_clks, pd->clks);
 err_put_subsys_clocks:
 	clk_bulk_put(pd->num_subsys_clks, pd->subsys_clks);
 err_put_clocks:
@@ -537,10 +525,7 @@ 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);
 
-	clk_bulk_unprepare(pd->num_clks, pd->clks);
 	clk_bulk_put(pd->num_clks, pd->clks);
-
-	clk_bulk_unprepare(pd->num_subsys_clks, pd->subsys_clks);
 	clk_bulk_put(pd->num_subsys_clks, pd->subsys_clks);
 }
 
-- 
2.32.0.rc0.204.g9fa02ecfa5-goog