On Fri, 2018-01-12 at 22:35 -0500, Alan Stern wrote:
> On Sat, 13 Jan 2018, Benjamin Herrenschmidt wrote:
>
> > The Aspeed SoCs use uhci-platform. With the new dynamic clock
> > control framework, the corresponding IP block clock must be
> > properly enabled.
> >
> > This is a simplified variant of what ehci-platform does, it
> > looks for *one* clock attached to the device, and if it's
> > there, enables it.
> >
> > Signed-off-by: Benjamin Herrenschmidt <benh@xxxxxxxxxxxxxxxxxxx>
> > ---
> >
> > v3. Fix tab vs. spaces and probe error path
> >
> > v2. Don't forget to git add latest changes :-) This adds the
> > part where we turn the clock off when removing the driver.
>
> >
> > drivers/usb/host/uhci-hcd.h | 3 +++
> > drivers/usb/host/uhci-platform.c | 24 ++++++++++++++++++++++--
> > 2 files changed, 25 insertions(+), 2 deletions(-)
> >
> > diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
> > index f1cc47292a59..7f9f33c8c232 100644
> > --- a/drivers/usb/host/uhci-hcd.h
> > +++ b/drivers/usb/host/uhci-hcd.h
> > @@ -4,6 +4,7 @@
> >
> > #include <linux/list.h>
> > #include <linux/usb.h>
> > +#include <linux/clk.h>
> >
> > #define usb_packetid(pipe) (usb_pipein(pipe) ? USB_PID_IN : USB_PID_OUT)
> > #define PIPE_DEVEP_MASK 0x0007ff00
> > @@ -447,6 +448,8 @@ struct uhci_hcd {
> > int total_load; /* Sum of array values */
> > short load[MAX_PHASE]; /* Periodic allocations */
> >
> > + struct clk *clk; /* (optional) clock source */
> > +
> > /* Reset host controller */
> > void (*reset_hc) (struct uhci_hcd *uhci);
> > int (*check_and_reset_hc) (struct uhci_hcd *uhci);
> > diff --git a/drivers/usb/host/uhci-platform.c b/drivers/usb/host/uhci-platform.c
> > index 6cb16d4b2257..0d86ad244922 100644
> > --- a/drivers/usb/host/uhci-platform.c
> > +++ b/drivers/usb/host/uhci-platform.c
> > @@ -89,6 +89,8 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)
> > if (!hcd)
> > return -ENOMEM;
> >
> > + uhci = hcd_to_uhci(hcd);
> > +
> > res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
> > hcd->regs = devm_ioremap_resource(&pdev->dev, res);
> > if (IS_ERR(hcd->regs)) {
> > @@ -98,8 +100,6 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)
> > hcd->rsrc_start = res->start;
> > hcd->rsrc_len = resource_size(res);
> >
> > - uhci = hcd_to_uhci(hcd);
> > -
>
> Any particular reason for moving this line up?
Yes, otherwise you can goto the error path without uhci initialized
>
> > uhci->regs = hcd->regs;
> >
> > /* Grab some things from the device-tree */
> > @@ -119,6 +119,21 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)
> > "Enabled Aspeed implementation workarounds\n");
> > }
> > }
> > +
> > + /* Get and enable clock if any specified */
> > + uhci->clk = devm_clk_get(&pdev->dev, NULL);
> > + if (IS_ERR(uhci->clk)) {
> > + ret = PTR_ERR(uhci->clk);
> > + goto err_rmr;
> > + }
> > + if (uhci->clk) {
> > + ret = clk_prepare_enable(uhci->clk);
> > + if (ret) {
> > + dev_err(&pdev->dev, "Error couldn't enable clock (%d)\n", ret);
> > + goto err_rmr;
> > + }
> > + }
> > +
> > ret = usb_add_hcd(hcd, pdev->resource[1].start, IRQF_SHARED);
> > if (ret)
> > goto err_rmr;
> > @@ -127,6 +142,8 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)
> > return 0;
> >
> > err_rmr:
> > + if (uhci->clk)
> > + clk_disable_unprepare(uhci->clk);
>
> You don't actually need the test here or below. Both clk_disable and
> clk_unprepare test for IS_ERR_OR_NULL.
Ah ok, it won't hurt tho, but I can do a v4 later or tomorrow.
> Anyway, this all looks okay. If you want to submit a v4, you can add
Thanks!
> Acked-by: Alan Stern <stern@xxxxxxxxxxxxxxxxxxx>
>
> Alan Stern
>
> > usb_put_hcd(hcd);
> >
> > return ret;
> > @@ -135,7 +152,10 @@ static int uhci_hcd_platform_probe(struct platform_device *pdev)
> > static int uhci_hcd_platform_remove(struct platform_device *pdev)
> > {
> > struct usb_hcd *hcd = platform_get_drvdata(pdev);
> > + struct uhci_hcd *uhci = hcd_to_uhci(hcd);
> >
> > + if (uhci->clk)
> > + clk_disable_unprepare(uhci->clk);
> > usb_remove_hcd(hcd);
> > usb_put_hcd(hcd);
>
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