stmmac: add clk management support

this patch adds the way to enable/disable the MAC
clock when call the open/close and resume/restore
functions.
This has been tested on ST platforms and SPEAr; thanks
to Francesco and Deepak.

Signed-off-by: Deepak Sikri <deepak.sikri@st.com>
Tested-by: Francesco Virlinzi <francesco.virlinzi@st.com>
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index b65d787..7182f15 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -22,6 +22,8 @@
 
 #define STMMAC_RESOURCE_NAME   "stmmaceth"
 #define DRV_MODULE_VERSION     "Feb_2012"
+
+#include <linux/clk.h>
 #include <linux/stmmac.h>
 #include <linux/phy.h>
 #include "common.h"
@@ -79,6 +81,9 @@ struct stmmac_priv {
        struct stmmac_counters mmc;
        struct dma_features dma_cap;
        int hw_cap_support;
+#ifdef CONFIG_HAVE_CLK
+       struct clk *stmmac_clk;
+#endif
 };
 
 extern int phyaddr;
@@ -97,3 +102,41 @@ int stmmac_dvr_remove(struct net_device *ndev);
 struct stmmac_priv *stmmac_dvr_probe(struct device *device,
                                     struct plat_stmmacenet_data *plat_dat,
                                     void __iomem *addr);
+
+#ifdef CONFIG_HAVE_CLK
+static inline int stmmac_clk_enable(struct stmmac_priv *priv)
+{
+       if (priv->stmmac_clk)
+               return clk_enable(priv->stmmac_clk);
+
+       return 0;
+}
+
+static inline void stmmac_clk_disable(struct stmmac_priv *priv)
+{
+       if (priv->stmmac_clk)
+               clk_disable(priv->stmmac_clk);
+}
+static inline int stmmac_clk_get(struct stmmac_priv *priv)
+{
+       priv->stmmac_clk = clk_get(priv->device, NULL);
+
+       if (IS_ERR(priv->stmmac_clk)) {
+               pr_err("%s: ERROR clk_get failed\n", __func__);
+               return PTR_ERR(priv->stmmac_clk);
+       }
+       return 0;
+}
+#else
+static inline int stmmac_clk_enable(struct stmmac_priv *priv)
+{
+       return 0;
+}
+static inline void stmmac_clk_disable(struct stmmac_priv *priv)
+{
+}
+static inline int stmmac_clk_get(struct stmmac_priv *priv)
+{
+       return 0;
+}
+#endif /* CONFIG_HAVE_CLK */

diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 933f63c..ddb47e1 100644 (file)
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -904,6 +904,8 @@ static int stmmac_open(struct net_device *dev)
        struct stmmac_priv *priv = netdev_priv(dev);
        int ret;
 
+       stmmac_clk_enable(priv);
+
        stmmac_check_ether_addr(priv);
 
        /* MDIO bus Registration */
@@ -911,13 +913,15 @@ static int stmmac_open(struct net_device *dev)
        if (ret < 0) {
                pr_debug("%s: MDIO bus (id: %d) registration failed",
                         __func__, priv->plat->bus_id);
-               return ret;
+               goto open_clk_dis;
        }
 
 #ifdef CONFIG_STMMAC_TIMER
        priv->tm = kzalloc(sizeof(struct stmmac_timer *), GFP_KERNEL);
-       if (unlikely(priv->tm == NULL))
-               return -ENOMEM;
+       if (unlikely(priv->tm == NULL)) {
+               ret = -ENOMEM;
+               goto open_clk_dis;
+       }
 
        priv->tm->freq = tmrate;
 
@@ -1034,6 +1038,8 @@ open_error:
        if (priv->phydev)
                phy_disconnect(priv->phydev);
 
+open_clk_dis:
+       stmmac_clk_disable(priv);
        return ret;
 }
 
@@ -1086,6 +1092,7 @@ static int stmmac_release(struct net_device *dev)
        stmmac_exit_fs();
 #endif
        stmmac_mdio_unregister(dev);
+       stmmac_clk_disable(priv);
 
        return 0;
 }
@@ -1880,6 +1887,9 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device,
                goto error;
        }
 
+       if (stmmac_clk_get(priv))
+               goto error;
+
        return priv;
 
 error:
@@ -1949,9 +1959,11 @@ int stmmac_suspend(struct net_device *ndev)
        /* Enable Power down mode by programming the PMT regs */
        if (device_may_wakeup(priv->device))
                priv->hw->mac->pmt(priv->ioaddr, priv->wolopts);
-       else
+       else {
                stmmac_set_mac(priv->ioaddr, false);
-
+               /* Disable clock in case of PWM is off */
+               stmmac_clk_disable(priv);
+       }
        spin_unlock(&priv->lock);
        return 0;
 }
@@ -1972,6 +1984,9 @@ int stmmac_resume(struct net_device *ndev)
         * from another devices (e.g. serial console). */
        if (device_may_wakeup(priv->device))
                priv->hw->mac->pmt(priv->ioaddr, 0);
+       else
+               /* enable the clk prevously disabled */
+               stmmac_clk_enable(priv);
 
        netif_device_attach(ndev);