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>

1 files changed, 31 insertions, 7 deletions

diff --git a/drivers/net/mv643xx_eth.c b/drivers/net/mv643xx_eth.c
index c99915740779..296687baccf7 100644
--- 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);