Re: [PATCH v3 2/3] usb: dwc3: add optional PHY interface clocks

[Thinh Nguyen <Thinh.Nguyen@synopsys.com>]

On Mon, Oct 09, 2023, Sebastian Reichel wrote:
> On Rockchip RK3588 one of the DWC3 cores is integrated weirdly and
> requires two extra clocks to be enabled. Without these extra clocks
> hot-plugging USB devices is broken.
> 
> Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>
> ---
>  drivers/usb/dwc3/core.c | 26 ++++++++++++++++++++++++++
>  drivers/usb/dwc3/core.h |  4 ++++
>  2 files changed, 30 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 9c6bf054f15d..fc60d5f564dd 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -817,8 +817,20 @@ static int dwc3_clk_enable(struct dwc3 *dwc)
>  	if (ret)
>  		goto disable_ref_clk;
>  
> +	ret = clk_prepare_enable(dwc->utmi_clk);
> +	if (ret)
> +		goto disable_susp_clk;
> +
> +	ret = clk_prepare_enable(dwc->pipe_clk);
> +	if (ret)
> +		goto disable_utmi_clk;
> +
>  	return 0;
>  
> +disable_utmi_clk:
> +	clk_disable_unprepare(dwc->utmi_clk);
> +disable_susp_clk:
> +	clk_disable_unprepare(dwc->susp_clk);
>  disable_ref_clk:
>  	clk_disable_unprepare(dwc->ref_clk);
>  disable_bus_clk:
> @@ -828,6 +840,8 @@ static int dwc3_clk_enable(struct dwc3 *dwc)
>  
>  static void dwc3_clk_disable(struct dwc3 *dwc)
>  {
> +	clk_disable_unprepare(dwc->pipe_clk);
> +	clk_disable_unprepare(dwc->utmi_clk);
>  	clk_disable_unprepare(dwc->susp_clk);
>  	clk_disable_unprepare(dwc->ref_clk);
>  	clk_disable_unprepare(dwc->bus_clk);
> @@ -1748,6 +1762,18 @@ static int dwc3_get_clocks(struct dwc3 *dwc)
>  		}
>  	}
>  

Can we add an inline comment here to note that these clocks are RKxxxx
specifics.

Thanks,
Thinh

> +	dwc->utmi_clk = devm_clk_get_optional(dev, "utmi");
> +	if (IS_ERR(dwc->utmi_clk)) {
> +		return dev_err_probe(dev, PTR_ERR(dwc->utmi_clk),
> +				"could not get utmi clock\n");
> +	}
> +
> +	dwc->pipe_clk = devm_clk_get_optional(dev, "pipe");
> +	if (IS_ERR(dwc->pipe_clk)) {
> +		return dev_err_probe(dev, PTR_ERR(dwc->pipe_clk),
> +				"could not get pipe clock\n");
> +	}
> +
>  	return 0;
>  }
>  
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index a69ac67d89fe..f5e6ae6e394e 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -991,6 +991,8 @@ struct dwc3_scratchpad_array {
>   * @bus_clk: clock for accessing the registers
>   * @ref_clk: reference clock
>   * @susp_clk: clock used when the SS phy is in low power (S3) state
> + * @utmi_clk: clock used for USB2 PHY communication
> + * @pipe_clk: clock used for USB3 PHY communication
>   * @reset: reset control
>   * @regs: base address for our registers
>   * @regs_size: address space size
> @@ -1156,6 +1158,8 @@ struct dwc3 {
>  	struct clk		*bus_clk;
>  	struct clk		*ref_clk;
>  	struct clk		*susp_clk;
> +	struct clk		*utmi_clk;
> +	struct clk		*pipe_clk;
>  
>  	struct reset_control	*reset;
>  
> -- 
> 2.42.0
>