From 5114c3ee24875270e9f9ef696c46832e5782587c Mon Sep 17 00:00:00 2001
From: Sean Anderson <sean.anderson@seco.com>
Date: Thu, 27 Jan 2022 15:06:32 -0500
Subject: [PATCH] usb: dwc3: Calculate REFCLKPER based on reference clock
Git-commit: 5114c3ee24875270e9f9ef696c46832e5782587c
References: jsc#PED-1817
Patch-mainline: v5.18-rc1
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: Robert Hancock <robert.hancock@calian.com>
Reviewed-by: Robert Hancock <robert.hancock@calian.com>
Reviewed-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Link: https://lore.kernel.org/r/20220127200636.1456175-4-sean.anderson@seco.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Oliver Neukum <oneukum@suse.com>
---
drivers/usb/dwc3/core.c | 14 ++++++++++++--
1 file changed, 12 insertions(+), 2 deletions(-)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 699ab9abdc47..38fef5c74359 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -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);
}
--
2.35.3