1 files changed, 131 insertions, 2 deletions

diff --git a/drivers/net/davinci_emac.c b/drivers/net/davinci_emac.c
index 25e14d2da75..28633761be2 100644
--- a/drivers/net/davinci_emac.c
+++ b/drivers/net/davinci_emac.c
@@ -298,6 +298,11 @@ static const char emac_version_string[] = "TI DaVinci EMAC Linux v6.1";
 #define EMAC_CTRL_EWCTL         (0x4)
 #define EMAC_CTRL_EWINTTCNT     (0x8)
 
+/* EMAC DM644x control module masks */
+#define EMAC_DM644X_EWINTCNT_MASK       0x1FFFF
+#define EMAC_DM644X_INTMIN_INTVL        0x1
+#define EMAC_DM644X_INTMAX_INTVL        (EMAC_DM644X_EWINTCNT_MASK)
+
 /* EMAC MDIO related */
 /* Mask & Control defines */
 #define MDIO_CONTROL_CLKDIV     (0xFF)
@@ -318,8 +323,20 @@ static const char emac_version_string[] = "TI DaVinci EMAC Linux v6.1";
 #define MDIO_CONTROL            (0x04)
 
 /* EMAC DM646X control module registers */
-#define EMAC_DM646X_CMRXINTEN   (0x14)
-#define EMAC_DM646X_CMTXINTEN   (0x18)
+#define EMAC_DM646X_CMINTCTRL   0x0C
+#define EMAC_DM646X_CMRXINTEN   0x14
+#define EMAC_DM646X_CMTXINTEN   0x18
+#define EMAC_DM646X_CMRXINTMAX  0x70
+#define EMAC_DM646X_CMTXINTMAX  0x74
+
+/* EMAC DM646X control module masks */
+#define EMAC_DM646X_INTPACEEN           (0x3 << 16)
+#define EMAC_DM646X_INTPRESCALE_MASK    (0x7FF << 0)
+#define EMAC_DM646X_CMINTMAX_CNT        63
+#define EMAC_DM646X_CMINTMIN_CNT        2
+#define EMAC_DM646X_CMINTMAX_INTVL      (1000 / EMAC_DM646X_CMINTMIN_CNT)
+#define EMAC_DM646X_CMINTMIN_INTVL      ((1000 / EMAC_DM646X_CMINTMAX_CNT) + 1)
+
 
 /* EMAC EOI codes for C0 */
 #define EMAC_DM646X_MAC_EOI_C0_RXEN     (0x01)
@@ -468,6 +485,8 @@ struct emac_priv {
         u32 duplex; /* Link duplex: 0=Half, 1=Full */
         u32 rx_buf_size;
         u32 isr_count;
+        u32 coal_intvl;
+        u32 bus_freq_mhz;
         u8 rmii_en;
         u8 version;
         u32 mac_hash1;
@@ -691,6 +710,103 @@ static int emac_set_settings(struct net_device *ndev, struct ethtool_cmd *ecmd)
 }
 
 /**
+ * emac_get_coalesce : Get interrupt coalesce settings for this device
+ * @ndev : The DaVinci EMAC network adapter
+ * @coal : ethtool coalesce settings structure
+ *
+ * Fetch the current interrupt coalesce settings
+ *
+ */
+static int emac_get_coalesce(struct net_device *ndev,
+                                struct ethtool_coalesce *coal)
+{
+        struct emac_priv *priv = netdev_priv(ndev);
+
+        coal->rx_coalesce_usecs = priv->coal_intvl;
+        return 0;
+
+}
+
+/**
+ * emac_set_coalesce : Set interrupt coalesce settings for this device
+ * @ndev : The DaVinci EMAC network adapter
+ * @coal : ethtool coalesce settings structure
+ *
+ * Set interrupt coalesce parameters
+ *
+ */
+static int emac_set_coalesce(struct net_device *ndev,
+                                struct ethtool_coalesce *coal)
+{
+        struct emac_priv *priv = netdev_priv(ndev);
+        u32 int_ctrl, num_interrupts = 0;
+        u32 prescale = 0, addnl_dvdr = 1, coal_intvl = 0;
+
+        if (!coal->rx_coalesce_usecs)
+                return -EINVAL;
+
+        coal_intvl = coal->rx_coalesce_usecs;
+
+        switch (priv->version) {
+        case EMAC_VERSION_2:
+                int_ctrl =  emac_ctrl_read(EMAC_DM646X_CMINTCTRL);
+                prescale = priv->bus_freq_mhz * 4;
+
+                if (coal_intvl < EMAC_DM646X_CMINTMIN_INTVL)
+                        coal_intvl = EMAC_DM646X_CMINTMIN_INTVL;
+
+                if (coal_intvl > EMAC_DM646X_CMINTMAX_INTVL) {
+                        /*
+                         * Interrupt pacer works with 4us Pulse, we can
+                         * throttle further by dilating the 4us pulse.
+                         */
+                        addnl_dvdr = EMAC_DM646X_INTPRESCALE_MASK / prescale;
+
+                        if (addnl_dvdr > 1) {
+                                prescale *= addnl_dvdr;
+                                if (coal_intvl > (EMAC_DM646X_CMINTMAX_INTVL
+                                                        * addnl_dvdr))
+                                        coal_intvl = (EMAC_DM646X_CMINTMAX_INTVL
+                                                        * addnl_dvdr);
+                        } else {
+                                addnl_dvdr = 1;
+                                coal_intvl = EMAC_DM646X_CMINTMAX_INTVL;
+                        }
+                }
+
+                num_interrupts = (1000 * addnl_dvdr) / coal_intvl;
+
+                int_ctrl |= EMAC_DM646X_INTPACEEN;
+                int_ctrl &= (~EMAC_DM646X_INTPRESCALE_MASK);
+                int_ctrl |= (prescale & EMAC_DM646X_INTPRESCALE_MASK);
+                emac_ctrl_write(EMAC_DM646X_CMINTCTRL, int_ctrl);
+
+                emac_ctrl_write(EMAC_DM646X_CMRXINTMAX, num_interrupts);
+                emac_ctrl_write(EMAC_DM646X_CMTXINTMAX, num_interrupts);
+
+                break;
+        default:
+                int_ctrl = emac_ctrl_read(EMAC_CTRL_EWINTTCNT);
+                int_ctrl &= (~EMAC_DM644X_EWINTCNT_MASK);
+                prescale = coal_intvl * priv->bus_freq_mhz;
+                if (prescale > EMAC_DM644X_EWINTCNT_MASK) {
+                        prescale = EMAC_DM644X_EWINTCNT_MASK;
+                        coal_intvl = prescale / priv->bus_freq_mhz;
+                }
+                emac_ctrl_write(EMAC_CTRL_EWINTTCNT, (int_ctrl | prescale));
+
+                break;
+        }
+
+        printk(KERN_INFO"Set coalesce to %d usecs.\n", coal_intvl);
+        priv->coal_intvl = coal_intvl;
+
+        return 0;
+
+}
+
+
+/**
  * ethtool_ops: DaVinci EMAC Ethtool structure
  *
  * Ethtool support for EMAC adapter
@@ -701,6 +817,8 @@ static const struct ethtool_ops ethtool_ops = {
         .get_settings = emac_get_settings,
         .set_settings = emac_set_settings,
         .get_link = ethtool_op_get_link,
+        .get_coalesce = emac_get_coalesce,
+        .set_coalesce =  emac_set_coalesce,
 };
 
 /**
@@ -2437,6 +2555,14 @@ static int emac_dev_open(struct net_device *ndev)
         /* Start/Enable EMAC hardware */
         emac_hw_enable(priv);
 
+        /* Enable Interrupt pacing if configured */
+        if (priv->coal_intvl != 0) {
+                struct ethtool_coalesce coal;
+
+                coal.rx_coalesce_usecs = (priv->coal_intvl << 4);
+                emac_set_coalesce(ndev, &coal);
+        }
+
         /* find the first phy */
         priv->phydev = NULL;
         if (priv->phy_mask) {
@@ -2677,6 +2803,9 @@ static int __devinit davinci_emac_probe(struct platform_device *pdev)
         priv->int_enable = pdata->interrupt_enable;
         priv->int_disable = pdata->interrupt_disable;
 
+        priv->coal_intvl = 0;
+        priv->bus_freq_mhz = (u32)(emac_bus_frequency / 1000000);
+
         emac_dev = &ndev->dev;
         /* Get EMAC platform data */
         res = platform_get_resource(pdev, IORESOURCE_MEM, 0);