Re: [PATCH 3/8] net: dwc_eth_qos: Add option "snps,reset-gpio" phy-rst gpio for stm32

[David Wu]

Hi Patrice,

在 2020/4/30 下午11:47, Patrice CHOTARD 写道:
@@ -701,6 +702,15 @@ static int eqos_start_resets_stm32(struct udevice *dev)
  
  	debug("%s(dev=%p):\n", __func__, dev);
        if (dm_gpio_is_valid(&eqos->phy_reset_gpio)) {
+               ret = dm_gpio_set_value(&eqos->phy_reset_gpio, 0);
+               if (ret < 0) {
+                       pr_err("dm_gpio_set_value(phy_reset, deassert) failed: 
%d",
+                              ret);
+                       return ret;
+               }
+
+               udelay(eqos->reset_delays[0]);
+
not related to this patch subject
                ret = dm_gpio_set_value(&eqos->phy_reset_gpio, 1);
                if (ret < 0) {
                        pr_err("dm_gpio_set_value(phy_reset, assert) failed: 
%d",
@@ -708,7 +718,7 @@ static int eqos_start_resets_stm32(struct udevice *dev)
                        return ret;
                }
  
-		udelay(2);
+               udelay(eqos->reset_delays[1]);
  
  		ret = dm_gpio_set_value(&eqos->phy_reset_gpio, 0);
                if (ret < 0) {

@@ -1712,11 +1724,29 @@ static int eqos_probe_resources_stm32(struct udevice 
*dev)
                if (ret)
                        pr_warn("gpio_request_by_name(phy reset) not provided 
%d",
                                ret);
+               else
+                       eqos->reset_delays[1] = 2;
this is not the correct place to set default value. It must be set in case we 
can't get value from DT below

No, three cases below, it is second case, and we can see udelay(2) in 
eqos_start_resets_stm32(), here we are to be compatible with the original.

- If there is not phy rst, reset_delays is 0;
- If "reset-gpios exists in phy node, reset_delays [1] = 2;
- "snps, reset-gpio" exists in DT, reset_delays is obtained from DT

  
  		eqos->phyaddr = ofnode_read_u32_default(phandle_args.node,
                                                        "reg", -1);
        }
  
+	if (!dm_gpio_is_valid(&eqos->phy_reset_gpio)) {
+               int reset_flags = GPIOD_IS_OUT;
+
+               if (dev_read_bool(dev, "snps,reset-active-low"))
+                       reset_flags |= GPIOD_ACTIVE_LOW;
+
+               ret = gpio_request_by_name(dev, "snps,reset-gpio", 0,
+                                          &eqos->phy_reset_gpio, reset_flags);
+               if (ret == 0)
+                       ret = dev_read_u32_array(dev, "snps,reset-delays-us",
+                                                eqos->reset_delays, 3);
in case "snps,reset-delays-us" is not in present DT, all resets-delays are set 
to 0, see my remark above
+               else
+                       pr_warn("gpio_request_by_name(snps,reset-gpio) failed: 
%d",
+                               ret);
+       }
+
        debug("%s: OK\n", __func__);
        return 0;