[PATCH linux dev-5.3 5/6] net: ftgmac100: Ungate RCLK for RMII on AST2600

[Cédric Le Goater]

On 22/09/2019 14:36, Andrew Jeffery wrote:
> The 50MHz RMII RCLK has to be enabled before the interface will function.
> 
> Signed-off-by: Andrew Jeffery <andrew at aj.id.au>
> ---
>  drivers/net/ethernet/faraday/ftgmac100.c | 43 ++++++++++++++++++++----
>  1 file changed, 36 insertions(+), 7 deletions(-)
> 
> diff --git a/drivers/net/ethernet/faraday/ftgmac100.c b/drivers/net/ethernet/faraday/ftgmac100.c
> index 9b7af94a40bb..21a58aad1a19 100644
> --- a/drivers/net/ethernet/faraday/ftgmac100.c
> +++ b/drivers/net/ethernet/faraday/ftgmac100.c
> @@ -90,6 +90,9 @@ struct ftgmac100 {
>  	struct mii_bus *mii_bus;
>  	struct clk *clk;
>  
> +	/* 2600 RMII clock gate */
> +	struct clk *rclk;
> +
>  	/* Link management */
>  	int cur_speed;
>  	int cur_duplex;
> @@ -1718,11 +1721,27 @@ static void ftgmac100_ncsi_handler(struct ncsi_dev *nd)
>  		   nd->link_up ? "up" : "down");
>  }
>  
> -static void ftgmac100_setup_clk(struct ftgmac100 *priv)
> +static int ftgmac100_setup_clk(struct ftgmac100 *priv)
>  {
> -	priv->clk = devm_clk_get(priv->dev, NULL);
> -	if (IS_ERR(priv->clk))
> -		return;
> +	struct clk *clk;
> +	bool is_ast2600;
> +
> +	is_ast2600 = of_device_is_compatible(priv->dev->of_node,
> +					     "aspeed,ast2600-mac");

why is ast2600 particular ? 

> +	clk = devm_clk_get(priv->dev, NULL /* MACCLK */);
> +	if (IS_ERR(clk))
> +		return PTR_ERR(clk);
> +	priv->clk = clk;
> +
> +	clk = devm_clk_get_optional(priv->dev, "RCLK");
> +	if (!clk && is_ast2600 && priv->use_ncsi) {
> +		dev_err(priv->dev, "Cannot ungate RCLK");
> +		return -EINVAL;
> +	}
> +
> +	priv->rclk = clk;
> +	clk_prepare_enable(priv->rclk);
>  
>  	clk_prepare_enable(priv->clk);
>  
> @@ -1732,6 +1751,8 @@ static void ftgmac100_setup_clk(struct ftgmac100 *priv)
>  	 */
>  	clk_set_rate(priv->clk, priv->use_ncsi ? FTGMAC_25MHZ :
>  			FTGMAC_100MHZ);
> +
> +	return 0;
>  }
>  
>  static int ftgmac100_probe(struct platform_device *pdev)
> @@ -1853,8 +1874,11 @@ static int ftgmac100_probe(struct platform_device *pdev)
>  			goto err_setup_mdio;
>  	}
>  
> -	if (priv->is_aspeed)
> -		ftgmac100_setup_clk(priv);
> +	if (priv->is_aspeed) {
> +		err = ftgmac100_setup_clk(priv);
> +		if (err)
> +			goto err_ncsi_dev;
> +	}
>  
>  	/* Default ring sizes */
>  	priv->rx_q_entries = priv->new_rx_q_entries = DEF_RX_QUEUE_ENTRIES;
> @@ -1886,8 +1910,11 @@ static int ftgmac100_probe(struct platform_device *pdev)
>  
>  	return 0;
>  
> -err_ncsi_dev:
>  err_register_netdev:
> +	if (priv->rclk)
> +		clk_disable_unprepare(priv->rclk);
> +	clk_disable_unprepare(priv->clk);
> +err_ncsi_dev:
>  	ftgmac100_destroy_mdio(netdev);
>  err_setup_mdio:
>  	iounmap(priv->base);
> @@ -1909,6 +1936,8 @@ static int ftgmac100_remove(struct platform_device *pdev)
>  
>  	unregister_netdev(netdev);
>  
> +	if (priv->rclk)
> +		clk_disable_unprepare(priv->rclk);
>  	clk_disable_unprepare(priv->clk);
>  
>  	/* There's a small chance the reset task will have been re-queued,
>