usb: uhci: Add clk support to uhci-platform

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@kernel.crashing.org>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/uhci-hcd.h b/drivers/usb/host/uhci-hcd.h
index f1cc472..7f9f33c 100644 (file)
--- 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 6cb16d4..89700e2 100644 (file)
--- 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);
-
        uhci->regs = hcd->regs;
 
        /* Grab some things from the device-tree */
@@ -119,13 +119,28 @@ 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;
+       }
+       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;
+               goto err_clk;
 
        device_wakeup_enable(hcd->self.controller);
        return 0;
 
+err_clk:
+       clk_disable_unprepare(uhci->clk);
 err_rmr:
        usb_put_hcd(hcd);
 
@@ -135,7 +150,9 @@ err_rmr:
 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);
 
+       clk_disable_unprepare(uhci->clk);
        usb_remove_hcd(hcd);
        usb_put_hcd(hcd);