[PATCH 1/4] usb: dwc3: Cache ref_clk pointer in struct dwc3

[Sean Anderson]

On 10/30/22 17:09, Marek Vasut wrote:
> Cache ref_clk clock pointer in struct dwc3 . This is a preparatory
> patch for subsequent backports from Linux kernel which configure
> GFLADJ register content based on the ref_clk rate and therefore need
> access to the ref_clk pointer.
> 
> Signed-off-by: Marek Vasut <marex at denx.de>
> ---
> Cc: Angus Ainslie <angus at akkea.ca>
> Cc: Bin Meng <bmeng.cn at gmail.com>
> Cc: Fabio Estevam <festevam at gmail.com>
> Cc: Kunihiko Hayashi <hayashi.kunihiko at socionext.com>
> Cc: Michal Simek <michal.simek at xilinx.com>
> Cc: Peng Fan <peng.fan at nxp.com>
> Cc: Sean Anderson <sean.anderson at seco.com>
> Cc: Stefano Babic <sbabic at denx.de>
> ---
>   drivers/usb/dwc3/core.h         | 3 +++
>   drivers/usb/dwc3/dwc3-generic.c | 9 +++++++++
>   2 files changed, 12 insertions(+)
> 
> diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
> index d7cce3a861a..0d20fe285b0 100644
> --- a/drivers/usb/dwc3/core.h
> +++ b/drivers/usb/dwc3/core.h
> @@ -668,6 +668,7 @@ struct dwc3_scratchpad_array {
>    * @event_buffer_list: a list of event buffers
>    * @gadget: device side representation of the peripheral controller
>    * @gadget_driver: pointer to the gadget driver
> + * @ref_clk: reference clock
>    * @regs: base address for our registers
>    * @regs_size: address space size
>    * @nr_scratch: number of scratch buffers
> @@ -766,6 +767,8 @@ struct dwc3 {
>   	struct usb_gadget	gadget;
>   	struct usb_gadget_driver *gadget_driver;
>   
> +	struct clk		*ref_clk;
> +
>   	void __iomem		*regs;
>   	size_t			regs_size;
>   
> diff --git a/drivers/usb/dwc3/dwc3-generic.c b/drivers/usb/dwc3/dwc3-generic.c
> index 466b25a0c38..78966718d01 100644
> --- a/drivers/usb/dwc3/dwc3-generic.c
> +++ b/drivers/usb/dwc3/dwc3-generic.c
> @@ -59,12 +59,21 @@ static int dwc3_generic_probe(struct udevice *dev,
>   	struct dwc3_generic_plat *plat = dev_get_plat(dev);
>   	struct dwc3 *dwc3 = &priv->dwc3;
>   	struct dwc3_glue_data *glue = dev_get_plat(dev->parent);
> +	int __maybe_unused index;
> +	ofnode __maybe_unused node;
>   
>   	dwc3->dev = dev;
>   	dwc3->maximum_speed = plat->maximum_speed;
>   	dwc3->dr_mode = plat->dr_mode;
>   #if CONFIG_IS_ENABLED(OF_CONTROL)
>   	dwc3_of_parse(dwc3);
> +
> +	node = dev_ofnode(dev->parent);
> +	index = ofnode_stringlist_search(node, "clock-names", "ref");
> +	if (index < 0)
> +		index = ofnode_stringlist_search(node, "clock-names", "ref_clk");
> +	if (index >= 0)
> +		dwc3->ref_clk = &glue->clks.clks[index];

clk_get_by_name_optional?

If you don't want to do that, document why please.

--Sean

>   #endif
>   
>   	/*