[PATCH 3/3] net: ftgmac100: Ungate RCLK for RMII on ASPEED MACs

[Andrew Jeffery]

The 50MHz RCLK has to be enabled before the RMII interface will function.

Signed-off-by: Andrew Jeffery <and...@aj.id.au>
---
 drivers/net/ethernet/faraday/ftgmac100.c | 35 +++++++++++++++++++-----
 1 file changed, 28 insertions(+), 7 deletions(-)

diff --git a/drivers/net/ethernet/faraday/ftgmac100.c 
b/drivers/net/ethernet/faraday/ftgmac100.c
index 9b7af94a40bb..9ff791fb0449 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;
@@ -1718,12 +1721,14 @@ 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;
 
+       clk = devm_clk_get(priv->dev, NULL /* MACCLK */);
+       if (IS_ERR(clk))
+               return PTR_ERR(clk);
+       priv->clk = clk;
        clk_prepare_enable(priv->clk);
 
        /* Aspeed specifies a 100MHz clock is required for up to
@@ -1732,6 +1737,14 @@ static void ftgmac100_setup_clk(struct ftgmac100 *priv)
         */
        clk_set_rate(priv->clk, priv->use_ncsi ? FTGMAC_25MHZ :
                        FTGMAC_100MHZ);
+
+       /* RCLK is for RMII, typically used for NCSI. Optional because its not
+        * necessary if it's the 2400 MAC or the MAC is configured for RGMII
+        */
+       priv->rclk = devm_clk_get_optional(priv->dev, "RCLK");
+       clk_prepare_enable(priv->rclk);
+
+       return 0;
 }
 
 static int ftgmac100_probe(struct platform_device *pdev)
@@ -1853,8 +1866,11 @@ 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 +1902,11 @@ 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 +1928,8 @@ 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,
-- 
2.20.1