usb: dwc3: Cache ref_clk pointer in struct dwc3

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.

It is possible to extract the clock pointer from existing clk_bulk
list of already claimed clock, no need to call clk_get*() again.

Reviewed-by: Sean Anderson <seanga2@gmail.com>
Signed-off-by: Marek Vasut <marex@denx.de>

diff --git a/drivers/usb/dwc3/core.h b/drivers/usb/dwc3/core.h
index d7cce3a..0d20fe2 100644 (file)
--- 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 466b25a..7896671 100644 (file)
--- 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];
 #endif
 
        /*