Commit 5114c3ee authored by Sean Anderson's avatar Sean Anderson Committed by Greg Kroah-Hartman
Browse files

usb: dwc3: Calculate REFCLKPER based on reference clock 



Instead of using a special property to determine the reference clock
period, use the rate of the reference clock. When we have a legacy
snps,ref-clock-period-ns property and no reference clock, use it
instead. Fractional clocks are not currently supported, and will be
dealt with in the next commit.

Tested-by: default avatarRobert Hancock <robert.hancock@calian.com>
Reviewed-by: default avatarRobert Hancock <robert.hancock@calian.com>
Reviewed-by: default avatarThinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: default avatarSean Anderson <sean.anderson@seco.com>
Link: https://lore.kernel.org/r/20220127200636.1456175-4-sean.anderson@seco.com


Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 33fb697e

drivers/usb/dwc3/core.c

+12 −2
Original line number Diff line number Diff line
@@ -347,14 +347,24 @@ static void dwc3_frame_length_adjustment(struct dwc3 *dwc) 
 */

static void dwc3_ref_clk_period(struct dwc3 *dwc)

{

	unsigned long period;

	unsigned long rate;

	u32 reg;



	if (dwc->ref_clk_per == 0)

	if (dwc->ref_clk) {

		rate = clk_get_rate(dwc->ref_clk);

		if (!rate)

			return;

		period = NSEC_PER_SEC / rate;

	} else if (dwc->ref_clk_per) {

		period = dwc->ref_clk_per;

	} else {

		return;

	}



	reg = dwc3_readl(dwc->regs, DWC3_GUCTL);

	reg &= ~DWC3_GUCTL_REFCLKPER_MASK;

	reg |=  FIELD_PREP(DWC3_GUCTL_REFCLKPER_MASK, dwc->ref_clk_per);

	reg |=  FIELD_PREP(DWC3_GUCTL_REFCLKPER_MASK, period);

	dwc3_writel(dwc->regs, DWC3_GUCTL, reg);

}