Hi,

On Wed, Sep 26, 2012 at 11:10:48AM +0530, ABRAHAM, KISHON VIJAY wrote:

Hi,

On Wed, Sep 19, 2012 at 5:26 PM, Felipe Balbi [off-list ref] wrote:

quoted

On Wed, Sep 19, 2012 at 05:00:29PM +0530, Kishon Vijay Abraham I wrote:

quoted

"usb_otg_ss_refclk960m" is needed by usb2 phy present in omap5. For
omap4, the clk_get of this clock will fail since it does not have this
clock.

Signed-off-by: Kishon Vijay Abraham I <redacted>
---
 Documentation/devicetree/bindings/usb/usb-phy.txt |    3 +++
 drivers/usb/phy/omap-usb2.c                       |   28 ++++++++++++++++++++-
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/Documentation/devicetree/bindings/usb/usb-phy.txt b/Documentation/devicetree/bindings/usb/usb-phy.txt
index 7c5fd89..d5626de 100644
--- a/Documentation/devicetree/bindings/usb/usb-phy.txt
+++ b/Documentation/devicetree/bindings/usb/usb-phy.txt

@@ -24,6 +24,9 @@ Required properties:
 add the address of control module phy power register until a driver for
 control module is added

+Optional properties:
+ - has960mhzclk: should be added if the phy needs 960mhz clock
+
 This is usually a subnode of ocp2scp to which it is connected.

 usb3phy@4a084400 {

diff --git a/drivers/usb/phy/omap-usb2.c b/drivers/usb/phy/omap-usb2.c
index d36c282..d6612ba 100644
--- a/drivers/usb/phy/omap-usb2.c
+++ b/drivers/usb/phy/omap-usb2.c

@@ -146,6 +146,7 @@ static int __devinit omap_usb2_probe(struct platform_device *pdev)
      struct omap_usb                 *phy;
      struct usb_otg                  *otg;
      struct resource                 *res;
+     struct device_node              *np = pdev->dev.of_node;

      phy = devm_kzalloc(&pdev->dev, sizeof(*phy), GFP_KERNEL);
      if (!phy) {

@@ -190,6 +191,15 @@ static int __devinit omap_usb2_probe(struct platform_device *pdev)
      }
      clk_prepare(phy->wkupclk);

+     if (of_property_read_bool(np, "has960mhzclk")) {
+             phy->optclk = devm_clk_get(phy->dev, "usb_otg_ss_refclk960m");
+             if (IS_ERR(phy->optclk)) {
+                     dev_err(&pdev->dev, "unable to get refclk960m\n");
+                     return PTR_ERR(phy->optclk);
+             }
+             clk_prepare(phy->optclk);
+     }

instead, can't you just always try to get the clock but ignore the error
if it fails ?

This clock is needed for usb2 to work in dwc3 (omap5). So we have to
report the error in case we dont get the clock no?

sure, but you don't need to bail out. Print a warning message such as:

dev_dbg(&pdev->dev, "couldn't get refclk960m, trying without\n");

or something similar. Then you don't need to add this has960mhzclk flag
to dts files.

-- 
balbi