Re: [PATCH] net: ftgmac100: Request clock and set speed

From: Florian Fainelli
Date: Tue Oct 10 2017 - 01:04:20 EST




On 10/09/2017 09:49 PM, Joel Stanley wrote:
> According to the ASPEED datasheet, gigabit speeds require a clock of
> 100MHz or higher. Other speeds require 25MHz or higher.
>
> Signed-off-by: Joel Stanley <joel@xxxxxxxxx>
> ---

> @@ -161,6 +170,9 @@ static int ftgmac100_reset_and_config_mac(struct ftgmac100 *priv)
> break;
> }
>
> + if (freq && priv->clk)
> + clk_set_rate(priv->clk, freq);

Checking for priv->clk should not be necessary all public clk APIs can
deal with a NULL clock pointer.

> +
> /* (Re)initialize the queue pointers */
> priv->rx_pointer = 0;
> priv->tx_clean_pointer = 0;
> @@ -1775,6 +1787,13 @@ static int ftgmac100_probe(struct platform_device *pdev)
> priv->dev = &pdev->dev;
> INIT_WORK(&priv->reset_task, ftgmac100_reset_task);
>
> + /* Enable clock if present */
> + priv->clk = devm_clk_get(&pdev->dev, NULL);
> + if (!IS_ERR(priv->clk))
> + clk_prepare_enable(priv->clk);
> + else
> + priv->clk = NULL;

Same here.

> +
> /* map io memory */
> priv->res = request_mem_region(res->start, resource_size(res),
> dev_name(&pdev->dev));
> @@ -1883,6 +1902,9 @@ static int ftgmac100_remove(struct platform_device *pdev)
>
> unregister_netdev(netdev);
>
> + if (priv->clk)
> + clk_disable_unprepare(priv->clk);

And here.

> +
> /* There's a small chance the reset task will have been re-queued,
> * during stop, make sure it's gone before we free the structure.
> */
>

--
Florian