usb: gadget: at91_udc: add usb_clk for transition to common clk framework

The AT91 PMC (Power Management Controller) provides an USB clock used by
USB Full Speed host (ohci) and USB Full Speed device (udc).
The usb drivers (ohci and udc) must configure this clock to 48Mhz.
This configuration was formely done in mach-at91/clock.c, but this
implementation will be removed when moving to common clk framework.

This patch adds support for usb clock retrieval and configuration, and is
backward compatible with the current at91 clk implementation (if usb clk
is not found, it does not configure/enable it).

Signed-off-by: Boris BREZILLON <b.brezillon@overkiz.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

diff --git a/drivers/usb/gadget/at91_udc.c b/drivers/usb/gadget/at91_udc.c
index 94d1d3cacce86a5df95f24bc2c25db4ab0f3d122..4cc4fd6d14738add8cafd229e5668f63107eef0b 100644 (file)
--- a/drivers/usb/gadget/at91_udc.c
+++ b/drivers/usb/gadget/at91_udc.c
@@ -870,6 +870,11 @@ static void clk_on(struct at91_udc *udc)
        if (udc->clocked)
                return;
        udc->clocked = 1;
+
+       if (IS_ENABLED(CONFIG_COMMON_CLK)) {
+               clk_set_rate(udc->uclk, 48000000);
+               clk_prepare_enable(udc->uclk);
+       }
        clk_prepare_enable(udc->iclk);
        clk_prepare_enable(udc->fclk);
 }
@@ -882,6 +887,8 @@ static void clk_off(struct at91_udc *udc)
        udc->gadget.speed = USB_SPEED_UNKNOWN;
        clk_disable_unprepare(udc->fclk);
        clk_disable_unprepare(udc->iclk);
+       if (IS_ENABLED(CONFIG_COMMON_CLK))
+               clk_disable_unprepare(udc->uclk);
 }
 
 /*
@@ -1774,10 +1781,12 @@ static int at91udc_probe(struct platform_device *pdev)
        /* get interface and function clocks */
        udc->iclk = clk_get(dev, "udc_clk");
        udc->fclk = clk_get(dev, "udpck");
-       if (IS_ERR(udc->iclk) || IS_ERR(udc->fclk)) {
+       if (IS_ENABLED(CONFIG_COMMON_CLK))
+               udc->uclk = clk_get(dev, "usb_clk");
+       if (IS_ERR(udc->iclk) || IS_ERR(udc->fclk) ||
+           (IS_ENABLED(CONFIG_COMMON_CLK) && IS_ERR(udc->uclk))) {
                DBG("clocks missing\n");
                retval = -ENODEV;
-               /* NOTE: we "know" here that refcounts on these are NOPs */
                goto fail1;
        }
 
@@ -1851,6 +1860,8 @@ fail3:
 fail2:
        free_irq(udc->udp_irq, udc);
 fail1:
+       if (IS_ENABLED(CONFIG_COMMON_CLK) && !IS_ERR(udc->uclk))
+               clk_put(udc->uclk);
        if (!IS_ERR(udc->fclk))
                clk_put(udc->fclk);
        if (!IS_ERR(udc->iclk))
@@ -1898,6 +1909,8 @@ static int __exit at91udc_remove(struct platform_device *pdev)
 
        clk_put(udc->iclk);
        clk_put(udc->fclk);
+       if (IS_ENABLED(CONFIG_COMMON_CLK))
+               clk_put(udc->uclk);
 
        return 0;
 }

diff --git a/drivers/usb/gadget/at91_udc.h b/drivers/usb/gadget/at91_udc.h
index e647d1c2ada4f2e3097783ebf5f4117672e08ef1..01752466338164e898b48a511078c5b2252b15a7 100644 (file)
--- a/drivers/usb/gadget/at91_udc.h
+++ b/drivers/usb/gadget/at91_udc.h
@@ -126,7 +126,7 @@ struct at91_udc {
        unsigned                        active_suspend:1;
        u8                              addr;
        struct at91_udc_data            board;
-       struct clk                      *iclk, *fclk;
+       struct clk                      *iclk, *fclk, *uclk;
        struct platform_device          *pdev;
        struct proc_dir_entry           *pde;
        void __iomem                    *udp_baseaddr;