Re: [PATCH v6 2/2] phy: rockchip-inno-usb2: add a new driver for Rockchip usb2phy

From: Guenter Roeck
Date: Fri Jun 17 2016 - 09:21:27 EST


Hi Frank,

On 06/16/2016 11:43 PM, Frank Wang wrote:
Hi Guenter,

On 2016/6/17 12:59, Guenter Roeck wrote:
On 06/16/2016 07:09 PM, Frank Wang wrote:
The newer SoCs (rk3366, rk3399) take a different usb-phy IP block
than rk3288 and before, and most of phy-related registers are also
different from the past, so a new phy driver is required necessarily.

Signed-off-by: Frank Wang <frank.wang@xxxxxxxxxxxxxx>
Suggested-by: Guenter Roeck <linux@xxxxxxxxxxxx>
Suggested-by: Doug Anderson <dianders@xxxxxxxxxxxx>
Reviewed-by: Heiko Stuebner <heiko@xxxxxxxxx>
Tested-by: Heiko Stuebner <heiko@xxxxxxxxx>
---

[ ... ]

+
+static int rockchip_usb2phy_resume(struct phy *phy)
+{
+ struct rockchip_usb2phy_port *rport = phy_get_drvdata(phy);
+ struct rockchip_usb2phy *rphy = dev_get_drvdata(phy->dev.parent);
+ int ret;
+
+ dev_dbg(&rport->phy->dev, "port resume\n");
+
+ ret = clk_prepare_enable(rphy->clk480m);
+ if (ret)
+ return ret;
+
If suspend can be called multiple times, resume can be called
multiple times as well. Doesn't this cause a clock imbalance
if you call clk_prepare_enable() multiple times on resume,
but clk_disable_unprepare() only once on suspend ?


Well, what you said is reasonable, How does something like below?

@@ -307,6 +307,9 @@ static int rockchip_usb2phy_resume(struct phy *phy)

dev_dbg(&rport->phy->dev, "port resume\n");

+ if (!rport->suspended)
+ return 0;
+
ret = clk_prepare_enable(rphy->clk480m);
if (ret)
return ret;
@@ -327,12 +330,16 @@ static int rockchip_usb2phy_suspend(struct phy *phy)

dev_dbg(&rport->phy->dev, "port suspend\n");

+ if (rport->suspended)
+ return 0;
+
ret = property_enable(rphy, &rport->port_cfg->phy_sus, true);
if (ret)
return ret;

rport->suspended = true;
clk_disable_unprepare(rphy->clk480m);
+
return 0;
}

@@ -485,6 +492,7 @@ static int rockchip_usb2phy_host_port_init(struct rockchip_usb2phy *rphy,

rport->port_id = USB2PHY_PORT_HOST;
rport->port_cfg = &rphy->phy_cfg->port_cfgs[USB2PHY_PORT_HOST];
+ rport->suspended = true;


Why does it start in suspended mode ? That seems odd.

Guenter

mutex_init(&rport->mutex);
INIT_DELAYED_WORK(&rport->sm_work, rockchip_usb2phy_sm_work);