Sean Anderson wrote:
> 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);
Please also document in dwc3 DT file whenever we add a new property.
Thanks,
Thinh
>
> 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;
