Hi Bin,
On Thu, 2019-05-16 at 02:12 -0700, Bin Meng wrote:
At present the link speed change callback is a nop. According to macb device tree bindings, an optional "tx_clk" is used to clock the ethernet controller's TX_CLK under different link speed.
In 10/100 MII mode, transmit logic must be clocked from a free running clock generated by the external PHY. In gigabit GMII mode, the controller, not the external PHY, must generate the 125 MHz transmit clock towards the PHY.
Signed-off-by: Bin Meng bmeng.cn@gmail.com
drivers/net/macb.c | 26 ++++++++++++++++++++++++++ 1 file changed, 26 insertions(+)
diff --git a/drivers/net/macb.c b/drivers/net/macb.c index b7f404e..7d86fa1 100644 --- a/drivers/net/macb.c +++ b/drivers/net/macb.c @@ -497,6 +497,32 @@ static int macb_phy_find(struct macb_device *macb, const char *name) #ifdef CONFIG_DM_ETH int __weak macb_linkspd_cb(struct udevice *dev, unsigned int speed) { +#ifdef CONFIG_CLK
- struct clk tx_clk;
- ulong rate;
- int ret;
- ret = clk_get_by_name(dev, "tx_clk", &tx_clk);
- if (ret)
return 0;
Can you return errors in ret here?
- switch (speed) {
- case _10BASET:
rate = 2500000;break;- case _100BASET:
rate = 25000000;break;- case _1000BASET:
- default:
rate = 125000000;break;
The Linux driver simply returns in the default case, without changing tx_clk. I am wondering if we should do the same in U-Boot?
- }
- if (tx_clk.dev)
clk_set_rate(&tx_clk, rate);
Can you also check the return value of clk_set_rate() here?
Thanks, Lukas
+#endif
- return 0;
} #else