This property allows setting the reference clock frequency properly for
ACPI-based systems. It is not documented under dt-bindings, since it is
not intended for use on DT-based systems. DT-based systems should use
the clocks property instead.
Frequency is preferred over period since it has greater precision when
used in calculations.
Signed-off-by: Sean Anderson <sean.anderson@xxxxxxxx>
---
Changes in v2:
- New
drivers/usb/dwc3/core.c | 6 ++++--
drivers/usb/dwc3/core.h | 4 +++-
2 files changed, 7 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
index 883e119377f0..5f3dc5f6cbcb 100644
--- a/drivers/usb/dwc3/core.c
+++ b/drivers/usb/dwc3/core.c
@@ -350,8 +350,8 @@ static void dwc3_ref_clk_period(struct dwc3 *dwc)
u32 reg;
unsigned long decr, fladj, rate, period;
- if (dwc->ref_clk) {
- rate = clk_get_rate(dwc->ref_clk);
+ if (dwc->ref_clk || dwc->ref_clk_freq) {
+ rate = clk_get_rate(dwc->ref_clk) ?: dwc->ref_clk_freq;
if (!rate)
return;
period = NSEC_PER_SEC / rate;
@@ -1492,6 +1492,8 @@ static void dwc3_get_properties(struct dwc3 *dwc)
&dwc->fladj);
device_property_read_u32(dev, "snps,ref-clock-period-ns",
&dwc->ref_clk_per);
+ device_property_read_u32(dev, "snps,ref-clock-frequency-hz",
+ &dwc->ref_clk_freq);
dwc->dis_metastability_quirk = device_property_read_bool(dev,
"snps,dis_metastability_quirk");
diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index eb9c1efced05..00a792459fec 100644
--- a/drivers/usb/dwc3/core.h
+++ b/drivers/usb/dwc3/core.h
@@ -988,7 +988,8 @@ struct dwc3_scratchpad_array {
* @regs: base address for our registers
* @regs_size: address space size
* @fladj: frame length adjustment
- * @ref_clk_per: reference clock period configuration
+ * @ref_clk_per: reference clock period; deprecated in favor of @ref_clk_freq
+ * @ref_clk_freq: reference clock frequency to use if @ref_clk is missing
* @irq_gadget: peripheral controller's IRQ number
* @otg_irq: IRQ number for OTG IRQs
* @current_otg_role: current role of operation while using the OTG block
@@ -1171,6 +1172,7 @@ struct dwc3 {
u32 fladj;
u32 ref_clk_per;
+ u32 ref_clk_freq;
u32 irq_gadget;
u32 otg_irq;
u32 current_otg_role;
--
2.25.1
