USB: ehci-atmel: add usb_clk for transition to CCF

The AT91 PMC (Power Management Controller) provides a USB clock used by
the different USB controllers (ehci, ohci and udc).
The atmel-ehci driver must configure the usb clock rate to 48Mhz in order
to get a fully functionnal USB host controller.
This configuration was formely done in mach-at91/clock.c, but will be
bypassed when moving to common clk framework.

This patch adds support for usb clock retrieval and configuration only if
CCF is enabled (CONFIG_COMMON_CLK).

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Cc: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/usb/host/ehci-atmel.c b/drivers/usb/host/ehci-atmel.c
index 3b645ff..f417526 100644 (file)
--- a/drivers/usb/host/ehci-atmel.c
+++ b/drivers/usb/host/ehci-atmel.c
@@ -30,13 +30,17 @@ static const char hcd_name[] = "ehci-atmel";
 static struct hc_driver __read_mostly ehci_atmel_hc_driver;
 
 /* interface and function clocks */
-static struct clk *iclk, *fclk;
+static struct clk *iclk, *fclk, *uclk;
 static int clocked;
 
 /*-------------------------------------------------------------------------*/
 
 static void atmel_start_clock(void)
 {
+       if (IS_ENABLED(CONFIG_COMMON_CLK)) {
+               clk_set_rate(uclk, 48000000);
+               clk_prepare_enable(uclk);
+       }
        clk_prepare_enable(iclk);
        clk_prepare_enable(fclk);
        clocked = 1;
@@ -46,6 +50,8 @@ static void atmel_stop_clock(void)
 {
        clk_disable_unprepare(fclk);
        clk_disable_unprepare(iclk);
+       if (IS_ENABLED(CONFIG_COMMON_CLK))
+               clk_disable_unprepare(uclk);
        clocked = 0;
 }
 
@@ -130,6 +136,14 @@ static int ehci_atmel_drv_probe(struct platform_device *pdev)
                retval = -ENOENT;
                goto fail_request_resource;
        }
+       if (IS_ENABLED(CONFIG_COMMON_CLK)) {
+               uclk = devm_clk_get(&pdev->dev, "usb_clk");
+               if (IS_ERR(uclk)) {
+                       dev_err(&pdev->dev, "failed to get uclk\n");
+                       retval = PTR_ERR(uclk);
+                       goto fail_request_resource;
+               }
+       }
 
        ehci = hcd_to_ehci(hcd);
        /* registers start at offset 0x0 */