[PATCH v2 3/7] usb: dwc3: Calculate REFCLKPER based on reference clock

From: Sean Anderson <sean.anderson@seco.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	linux-usb@vger.kernel.org
Cc: Felipe Balbi <balbi@kernel.org>,
	Thinh Nguyen <Thinh.Nguyen@synopsys.com>,
	Balaji Prakash J <bjagadee@codeaurora.org>,
	linux-kernel@vger.kernel.org,
	Robert Hancock <robert.hancock@calian.com>,
	Baruch Siach <baruch@tkos.co.il>,
	Sean Anderson <sean.anderson@seco.com>
Subject: [PATCH v2 3/7] usb: dwc3: Calculate REFCLKPER based on reference clock
Date: Tue, 18 Jan 2022 19:24:33 -0500	[thread overview]
Message-ID: <20220119002438.106079-4-sean.anderson@seco.com> (raw)
In-Reply-To: <20220119002438.106079-1-sean.anderson@seco.com>

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.

Signed-off-by: Sean Anderson <sean.anderson@seco.com>
---

(no changes since v1)

 drivers/usb/dwc3/core.c | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 699ab9abdc47..5214daceda86 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -348,13 +348,22 @@ static void dwc3_frame_length_adjustment(struct dwc3 *dwc)
 static void dwc3_ref_clk_period(struct dwc3 *dwc)
 {
 	u32 reg;
+	unsigned long rate, period;
 
-	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);
 }
 
-- 
2.25.1

