[PATCH] usb: dwc3: fix backwards compat with rockchip devices

[Heiko Stuebner]

Am Samstag, 9. April 2022, 17:21:15 CEST schrieb Peter Geis:
> Commit 33fb697ec7e5 ("usb: dwc3: Get clocks individually") moved from
> the clk_bulk api to individual clocks, following the snps,dwc3.yaml
> dt-binding for clock names.
> Unfortunately the rk3328 (and upcoming rk356x support) use the
> rockchip,dwc3.yaml which has different clock names, which are common on
> devices using the glue layer.
> The rk3328 does not use a glue layer, but attaches directly to the dwc3
> core driver.
> The offending patch series failed to account for this, thus dwc3 was
> broken on rk3328.
> 
> To retain backwards compatibility with rk3328 device trees we must also
> check for the alternate clock names.
> 
> Fixes: 33fb697ec7e5 ("usb: dwc3: Get clocks individually")
> 
> Reported-by: Frank Wunderlich <frank-w at public-files.de>
> Signed-off-by: Peter Geis <pgwipeout at gmail.com>

Reviewed-by: Heiko Stuebner <heiko at sntech.de>

> ---
> 
> This patch is standalone to fix the backwards compatibility, and is
> necessary no matter if we decide to retain the clock names in
> rockchip,dwc3.yaml as is or align with snps,dwc3.yaml.
> 
>  drivers/usb/dwc3/core.c | 23 +++++++++++++++++++++++
>  1 file changed, 23 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/core.c b/drivers/usb/dwc3/core.c
> index 1170b800acdc..5bfd3e88af35 100644
> --- a/drivers/usb/dwc3/core.c
> +++ b/drivers/usb/dwc3/core.c
> @@ -1690,21 +1690,44 @@ static int dwc3_probe(struct platform_device *pdev)
>  		/*
>  		 * Clocks are optional, but new DT platforms should support all
>  		 * clocks as required by the DT-binding.
> +		 * Some devices have different clock names in legacy device trees,
> +		 * check for them to retain backwards compatibility.
>  		 */
>  		dwc->bus_clk = devm_clk_get_optional(dev, "bus_early");
>  		if (IS_ERR(dwc->bus_clk))
>  			return dev_err_probe(dev, PTR_ERR(dwc->bus_clk),
>  					     "could not get bus clock\n");
>  
> +		if (dwc->bus_clk == NULL) {
> +			dwc->bus_clk = devm_clk_get_optional(dev, "bus_clk");
> +			if (IS_ERR(dwc->bus_clk))
> +				return dev_err_probe(dev, PTR_ERR(dwc->bus_clk),
> +						     "could not get bus clock\n");
> +		}
> +
>  		dwc->ref_clk = devm_clk_get_optional(dev, "ref");
>  		if (IS_ERR(dwc->ref_clk))
>  			return dev_err_probe(dev, PTR_ERR(dwc->ref_clk),
>  					     "could not get ref clock\n");
>  
> +		if (dwc->ref_clk == NULL) {
> +			dwc->ref_clk = devm_clk_get_optional(dev, "ref_clk");
> +			if (IS_ERR(dwc->ref_clk))
> +				return dev_err_probe(dev, PTR_ERR(dwc->ref_clk),
> +						     "could not get ref clock\n");
> +		}
> +
>  		dwc->susp_clk = devm_clk_get_optional(dev, "suspend");
>  		if (IS_ERR(dwc->susp_clk))
>  			return dev_err_probe(dev, PTR_ERR(dwc->susp_clk),
>  					     "could not get suspend clock\n");
> +
> +		if (dwc->susp_clk == NULL) {
> +			dwc->susp_clk = devm_clk_get_optional(dev, "suspend_clk");
> +			if (IS_ERR(dwc->susp_clk))
> +				return dev_err_probe(dev, PTR_ERR(dwc->susp_clk),
> +						     "could not get suspend clock\n");
> +		}
>  	}
>  
>  	ret = reset_control_deassert(dwc->reset);
>