[PATCH v4 0/2] phy: rockchip-inno-usb2: correct 480MHz clk_ops callbacks and stable time

[PATCH v4 0/2] phy: rockchip-inno-usb2: correct 480MHz clk_ops callbacks and stable time

[William Wu]

This series try to correct the 480MHz output clock of USB2 PHY
clk_ops callback and fix the delay time. It aims to make the
480MHz clock gate more sensible and stable.

Tested on rk3366/rk3399 EVB board.

William Wu (2):
  phy: rockchip-inno-usb2: correct clk_ops callback
  phy: rockchip-inno-usb2: correct 480MHz output clock stable time

 drivers/phy/phy-rockchip-inno-usb2.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

-- 
2.0.0


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[PATCH v4 1/2] phy: rockchip-inno-usb2: correct clk_ops callback

[William Wu]

Since we needs to delay ~1ms to wait for 480MHz output clock
of USB2 PHY to become stable after turn on it, the delay time
is pretty long for something that's supposed to be "atomic"
like a clk_enable(). Consider that clk_enable() will disable
interrupt and that a 1ms interrupt latency is not sensible.

The 480MHz output clock should be handled in prepare callbacks
which support gate a clk if the operation may sleep.

Signed-off-by: William Wu <wulf@rock-chips.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
---
Changes in v4:
- add Reviewed-by

Changes in v3:
- None

Changes in v2:
- None

 drivers/phy/phy-rockchip-inno-usb2.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

diff --git a/drivers/phy/phy-rockchip-inno-usb2.c b/drivers/phy/phy-rockchip-inno-usb2.c
index ac20310..365e077 100644
--- a/drivers/phy/phy-rockchip-inno-usb2.c
+++ b/drivers/phy/phy-rockchip-inno-usb2.c
@@ -153,7 +153,7 @@ static inline bool property_enabled(struct rockchip_usb2phy *rphy,
 	return tmp == reg->enable;
 }
 
-static int rockchip_usb2phy_clk480m_enable(struct clk_hw *hw)
+static int rockchip_usb2phy_clk480m_prepare(struct clk_hw *hw)
 {
 	struct rockchip_usb2phy *rphy =
 		container_of(hw, struct rockchip_usb2phy, clk480m_hw);
@@ -172,7 +172,7 @@ static int rockchip_usb2phy_clk480m_enable(struct clk_hw *hw)
 	return 0;
 }
 
-static void rockchip_usb2phy_clk480m_disable(struct clk_hw *hw)
+static void rockchip_usb2phy_clk480m_unprepare(struct clk_hw *hw)
 {
 	struct rockchip_usb2phy *rphy =
 		container_of(hw, struct rockchip_usb2phy, clk480m_hw);
@@ -181,7 +181,7 @@ static void rockchip_usb2phy_clk480m_disable(struct clk_hw *hw)
 	property_enable(rphy, &rphy->phy_cfg->clkout_ctl, false);
 }
 
-static int rockchip_usb2phy_clk480m_enabled(struct clk_hw *hw)
+static int rockchip_usb2phy_clk480m_prepared(struct clk_hw *hw)
 {
 	struct rockchip_usb2phy *rphy =
 		container_of(hw, struct rockchip_usb2phy, clk480m_hw);
@@ -197,9 +197,9 @@ rockchip_usb2phy_clk480m_recalc_rate(struct clk_hw *hw,
 }
 
 static const struct clk_ops rockchip_usb2phy_clkout_ops = {
-	.enable = rockchip_usb2phy_clk480m_enable,
-	.disable = rockchip_usb2phy_clk480m_disable,
-	.is_enabled = rockchip_usb2phy_clk480m_enabled,
+	.prepare = rockchip_usb2phy_clk480m_prepare,
+	.unprepare = rockchip_usb2phy_clk480m_unprepare,
+	.is_prepared = rockchip_usb2phy_clk480m_prepared,
 	.recalc_rate = rockchip_usb2phy_clk480m_recalc_rate,
 };
 
-- 
2.0.0

[PATCH v4 2/2] phy: rockchip-inno-usb2: correct 480MHz output clock stable time

[William Wu]

We found that the system crashed due to 480MHz output clock of
USB2 PHY was unstable after clock had been enabled by gpu module.

Theoretically, 1 millisecond is a critical value for 480MHz
output clock stable time, so we try to change the delay time
to 1.2 millisecond to avoid this issue.

And the commit ed907fb1d7c3 ("phy: rockchip-inno-usb2: correct
clk_ops callback") used prepare callbacks instead of enable
callbacks to support gate a clk if the operation may sleep. So
we can switch from delay to sleep functions.

Also fix a spelling error from "waitting" to "waiting".

Signed-off-by: William Wu <wulf-TNX95d0MmH7DzftRWevZcw@public.gmane.org>
Reviewed-by: Douglas Anderson <dianders-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
---
Changes in v4:
- add Reviewed-by and fix a spelling error

Changes in v3:
- None

Changes in v2:
- None

 drivers/phy/phy-rockchip-inno-usb2.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/phy/phy-rockchip-inno-usb2.c b/drivers/phy/phy-rockchip-inno-usb2.c
index 365e077..5d922fc 100644
--- a/drivers/phy/phy-rockchip-inno-usb2.c
+++ b/drivers/phy/phy-rockchip-inno-usb2.c
@@ -165,8 +165,8 @@ static int rockchip_usb2phy_clk480m_prepare(struct clk_hw *hw)
 		if (ret)
 			return ret;
 
-		/* waitting for the clk become stable */
-		mdelay(1);
+		/* waiting for the clk become stable */
+		usleep_range(1200, 1300);
 	}
 
 	return 0;
-- 
2.0.0


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Re: [PATCH v4 0/2] phy: rockchip-inno-usb2: correct 480MHz clk_ops callbacks and stable time

[Kishon Vijay Abraham I]

On Tuesday 15 November 2016 09:24 AM, William Wu wrote:
> This series try to correct the 480MHz output clock of USB2 PHY
> clk_ops callback and fix the delay time. It aims to make the
> 480MHz clock gate more sensible and stable.
> 
> Tested on rk3366/rk3399 EVB board.

merged to phy -next.

Thanks
Kishon
> 
> William Wu (2):
>   phy: rockchip-inno-usb2: correct clk_ops callback
>   phy: rockchip-inno-usb2: correct 480MHz output clock stable time
> 
>  drivers/phy/phy-rockchip-inno-usb2.c | 16 ++++++++--------
>  1 file changed, 8 insertions(+), 8 deletions(-)
>