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

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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>
This commit is contained in:
Boris BREZILLON 2013-10-18 21:26:51 +02:00 committed by Greg Kroah-Hartman
parent 9983d6dc4e
commit 0d768fcfc0
1 changed files with 15 additions and 1 deletions
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16
drivers/usb/host/ehci-atmel.c
View file

@ -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 */