[PATCH] soc: amlogic: meson-gx-pwrc-vpu: fix power-off when powered by bootloader

[Neil Armstrong]

In the case the VPU power domain has been powered on by the bootloader
and no driver are attached to this power domain, the genpd will power it
off after a certain amount of time, but the clocks hasn't been enabled
by the kernel itself and the power-off will trigger some faults.
This patch enable the clocks to have a coherent state for an eventual
poweroff and switches to the pm_domain_always_on_gov governor.

Fixes: 75fcb5ca4b46 ("soc: amlogic: add Meson GX VPU Domains driver")
Signed-off-by: Neil Armstrong <narmstrong at baylibre.com>
---
 drivers/soc/amlogic/meson-gx-pwrc-vpu.c | 29 +++++++++++++++++++----------
 1 file changed, 19 insertions(+), 10 deletions(-)

diff --git a/drivers/soc/amlogic/meson-gx-pwrc-vpu.c b/drivers/soc/amlogic/meson-gx-pwrc-vpu.c
index bf5190b..2bdeebc 100644
--- a/drivers/soc/amlogic/meson-gx-pwrc-vpu.c
+++ b/drivers/soc/amlogic/meson-gx-pwrc-vpu.c
@@ -34,7 +34,6 @@ struct meson_gx_pwrc_vpu {
 	struct reset_control *rstc;
 	struct clk *vpu_clk;
 	struct clk *vapb_clk;
-	bool powered;
 };
 
 static inline
@@ -78,8 +77,6 @@ static int meson_gx_pwrc_vpu_power_off(struct generic_pm_domain *genpd)
 	clk_disable_unprepare(pd->vpu_clk);
 	clk_disable_unprepare(pd->vapb_clk);
 
-	pd->powered = false;
-
 	return 0;
 }
 
@@ -91,7 +88,11 @@ static int meson_gx_pwrc_vpu_setup_clk(struct meson_gx_pwrc_vpu *pd)
 	if (ret)
 		return ret;
 
-	return clk_prepare_enable(pd->vapb_clk);
+	ret = clk_prepare_enable(pd->vapb_clk);
+	if (ret)
+		clk_disable_unprepare(pd->vpu_clk);
+
+	return ret;
 }
 
 static int meson_gx_pwrc_vpu_power_on(struct generic_pm_domain *genpd)
@@ -139,8 +140,6 @@ static int meson_gx_pwrc_vpu_power_on(struct generic_pm_domain *genpd)
 	if (ret)
 		return ret;
 
-	pd->powered = true;
-
 	return 0;
 }
 
@@ -167,6 +166,8 @@ static int meson_gx_pwrc_vpu_probe(struct platform_device *pdev)
 	struct reset_control *rstc;
 	struct clk *vpu_clk;
 	struct clk *vapb_clk;
+	bool powered_off;
+	int ret;
 
 	regmap_ao = syscon_node_to_regmap(of_get_parent(pdev->dev.of_node));
 	if (IS_ERR(regmap_ao)) {
@@ -205,8 +206,17 @@ static int meson_gx_pwrc_vpu_probe(struct platform_device *pdev)
 	vpu_hdmi_pd.vpu_clk = vpu_clk;
 	vpu_hdmi_pd.vapb_clk = vapb_clk;
 
-	pm_genpd_init(&vpu_hdmi_pd.genpd, &simple_qos_governor,
-		      meson_gx_pwrc_vpu_get_power(&vpu_hdmi_pd));
+	powered_off = meson_gx_pwrc_vpu_get_power(&vpu_hdmi_pd);
+
+	/* If already powered, sync the clock states */
+	if (!powered_off) {
+		ret = meson_gx_pwrc_vpu_setup_clk(&vpu_hdmi_pd);
+		if (ret)
+			return ret;
+	}
+
+	pm_genpd_init(&vpu_hdmi_pd.genpd, &pm_domain_always_on_gov,
+		      powered_off);
 
 	return of_genpd_add_provider_simple(pdev->dev.of_node,
 					    &vpu_hdmi_pd.genpd);
@@ -214,8 +224,7 @@ static int meson_gx_pwrc_vpu_probe(struct platform_device *pdev)
 
 static void meson_gx_pwrc_vpu_shutdown(struct platform_device *pdev)
 {
-	if (vpu_hdmi_pd.powered)
-		meson_gx_pwrc_vpu_power_off(&vpu_hdmi_pd.genpd);
+	meson_gx_pwrc_vpu_power_off(&vpu_hdmi_pd.genpd);
 }
 
 static const struct of_device_id meson_gx_pwrc_vpu_match_table[] = {
-- 
2.7.4