mv643xx_eth: detect extended rx coal register field

Newer hardware has a 16-bit instead of a 14-bit RX coalescing
count field in the SDMA_CONFIG register.  This patch adds a run-time
check for which of the two we have, and adjusts further writes to the
rx coal count field accordingly.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Acked-by: Dale Farnsworth <dale@farnsworth.org>

diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index c9991574077990cb074647a7141d59b407767ab3..296687baccf757826dd000a071fac4ffadecd7e9 100644 (file)
--- a/drivers/net/mv643xx_eth.c
+++ b/drivers/net/mv643xx_eth.c
@@ -249,6 +249,7 @@ struct mv643xx_eth_shared_private {
         * Hardware-specific parameters.
         */
        unsigned int t_clk;
+       int extended_rx_coal_limit;
 };
 
 
@@ -1815,14 +1816,22 @@ static void port_start(struct mv643xx_eth_private *mp)
 static void set_rx_coal(struct mv643xx_eth_private *mp, unsigned int delay)
 {
        unsigned int coal = ((mp->shared->t_clk / 1000000) * delay) / 64;
+       u32 val;
 
-       if (coal > 0x3fff)
-               coal = 0x3fff;
-
-       wrl(mp, SDMA_CONFIG(mp->port_num),
-               ((coal & 0x3fff) << 8) |
-               (rdl(mp, SDMA_CONFIG(mp->port_num))
-                       & 0xffc000ff));
+       val = rdl(mp, SDMA_CONFIG(mp->port_num));
+       if (mp->shared->extended_rx_coal_limit) {
+               if (coal > 0xffff)
+                       coal = 0xffff;
+               val &= ~0x023fff80;
+               val |= (coal & 0x8000) << 10;
+               val |= (coal & 0x7fff) << 7;
+       } else {
+               if (coal > 0x3fff)
+                       coal = 0x3fff;
+               val &= ~0x003fff00;
+               val |= (coal & 0x3fff) << 8;
+       }
+       wrl(mp, SDMA_CONFIG(mp->port_num), val);
 }
 
 static void set_tx_coal(struct mv643xx_eth_private *mp, unsigned int delay)
@@ -2087,6 +2096,20 @@ mv643xx_eth_conf_mbus_windows(struct mv643xx_eth_shared_private *msp,
        msp->win_protect = win_protect;
 }
 
+static void infer_hw_params(struct mv643xx_eth_shared_private *msp)
+{
+       /*
+        * Check whether we have a 14-bit coal limit field in bits
+        * [21:8], or a 16-bit coal limit in bits [25,21:7] of the
+        * SDMA config register.
+        */
+       writel(0x02000000, msp->base + SDMA_CONFIG(0));
+       if (readl(msp->base + SDMA_CONFIG(0)) & 0x02000000)
+               msp->extended_rx_coal_limit = 1;
+       else
+               msp->extended_rx_coal_limit = 0;
+}
+
 static int mv643xx_eth_shared_probe(struct platform_device *pdev)
 {
        static int mv643xx_eth_version_printed = 0;
@@ -2125,6 +2148,7 @@ static int mv643xx_eth_shared_probe(struct platform_device *pdev)
         * Detect hardware parameters.
         */
        msp->t_clk = (pd != NULL && pd->t_clk != 0) ? pd->t_clk : 133000000;
+       infer_hw_params(msp);
 
        platform_set_drvdata(pdev, msp);