fs_enet: cleanup clock API use

make the Freescale ethernet driver get, prepare and enable the FEC clock
during probe(); disable and unprepare the clock upon remove(), put is
done by the devm approach; hold a reference to the clock over the period
of use.

clock lookup is non-fatal as not all platforms provide clock specs in
their device tree; failure to enable specified clocks is fatal.

Signed-off-by: Gerhard Sittig <gsi@denx.de>
Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
index c04eb3aeb8343eb56ca26a7a4f1dd0793b2370bc..6b60582ce8cf1c7a82dd3da1d69acb64981014f4 100644 (file)
--- a/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
+++ b/drivers/net/ethernet/freescale/fs_enet/fs_enet-main.c
@@ -999,6 +999,8 @@ static int fs_enet_probe(struct platform_device *ofdev)
        struct fs_enet_private *fep;
        struct fs_platform_info *fpi;
        const u32 *data;
+       struct clk *clk;
+       int err;
        const u8 *mac_addr;
        const char *phy_connection_type;
        int privsize, len, ret = -ENODEV;
@@ -1036,6 +1038,20 @@ static int fs_enet_probe(struct platform_device *ofdev)
                        fpi->use_rmii = 1;
        }
 
+       /* make clock lookup non-fatal (the driver is shared among platforms),
+        * but require enable to succeed when a clock was specified/found,
+        * keep a reference to the clock upon successful acquisition
+        */
+       clk = devm_clk_get(&ofdev->dev, "per");
+       if (!IS_ERR(clk)) {
+               err = clk_prepare_enable(clk);
+               if (err) {
+                       ret = err;
+                       goto out_free_fpi;
+               }
+               fpi->clk_per = clk;
+       }
+
        privsize = sizeof(*fep) +
                   sizeof(struct sk_buff **) *
                   (fpi->rx_ring + fpi->tx_ring);
@@ -1107,6 +1123,8 @@ out_free_dev:
        free_netdev(ndev);
 out_put:
        of_node_put(fpi->phy_node);
+       if (fpi->clk_per)
+               clk_disable_unprepare(fpi->clk_per);
 out_free_fpi:
        kfree(fpi);
        return ret;
@@ -1123,6 +1141,8 @@ static int fs_enet_remove(struct platform_device *ofdev)
        fep->ops->cleanup_data(ndev);
        dev_set_drvdata(fep->dev, NULL);
        of_node_put(fep->fpi->phy_node);
+       if (fep->fpi->clk_per)
+               clk_disable_unprepare(fep->fpi->clk_per);
        free_netdev(ndev);
        return 0;
 }

diff --git a/include/linux/fs_enet_pd.h b/include/linux/fs_enet_pd.h
index 343d82a5446877c7f641ed27e01fd8927cc48036..efb05961bdd8fbebbde2d2f534f486defe1ca095 100644 (file)
--- a/include/linux/fs_enet_pd.h
+++ b/include/linux/fs_enet_pd.h
@@ -16,6 +16,7 @@
 #ifndef FS_ENET_PD_H
 #define FS_ENET_PD_H
 
+#include <linux/clk.h>
 #include <linux/string.h>
 #include <linux/of_mdio.h>
 #include <linux/if_ether.h>
@@ -143,6 +144,8 @@ struct fs_platform_info {
 
        int use_rmii;           /* use RMII mode               */
        int has_phy;            /* if the network is phy container as well...*/
+
+       struct clk *clk_per;    /* 'per' clock for register access */
 };
 struct fs_mii_fec_platform_info {
        u32 irq[32];