[U-Boot] [PATCH 4/4] macb: allow GEM to have configurable receive buffer size
Dave Aldridge
fovsoft at gmail.com
Thu Aug 18 15:32:19 CEST 2011
GEM has configurable receive buffer sizes so requires this to be
programmed up.
Signed-off-by: Dave Aldridge <fovsoft at gmail.com>
---
drivers/net/macb.c | 19 +++++++++++++++++++
drivers/net/macb.h | 5 +++++
2 files changed, 24 insertions(+), 0 deletions(-)
diff --git a/drivers/net/macb.c b/drivers/net/macb.c
index 41f1dce..4d21f14 100644
--- a/drivers/net/macb.c
+++ b/drivers/net/macb.c
@@ -436,6 +436,23 @@ static int macb_phy_init(struct macb_device *macb)
}
}
+/*
+ * Configure the receive DMA engine to use the correct receive buffer size.
+ * This is a configurable parameter for GEM.
+ */
+static void macb_configure_dma(struct macb_device *macb)
+{
+ u32 dmacfg;
+ u32 rx_ring_buf_size = CONFIG_SYS_MACB_RX_BUFFER_SIZE /
+ CONFIG_SYS_MACB_RX_RING_SIZE;
+
+ if (macb->is_gem) {
+ dmacfg = gem_readl(macb, DMACFG) & ~GEM_BF(RXBS, -1L);
+ dmacfg |= GEM_BF(RXBS, rx_ring_buf_size / 64);
+ gem_writel(macb, DMACFG, dmacfg);
+ }
+}
+
static int macb_init(struct eth_device *netdev, bd_t *bd)
{
struct macb_device *macb = to_macb(netdev);
@@ -465,6 +482,8 @@ static int macb_init(struct eth_device *netdev, bd_t *bd)
}
macb->rx_tail = macb->tx_head = macb->tx_tail = 0;
+ macb_configure_dma(macb);
+
macb_writel(macb, RBQP, macb->rx_ring_dma);
macb_writel(macb, TBQP, macb->tx_ring_dma);
diff --git a/drivers/net/macb.h b/drivers/net/macb.h
index c0759cf..e0fbd46 100644
--- a/drivers/net/macb.h
+++ b/drivers/net/macb.h
@@ -76,6 +76,7 @@
/* GEM register offsets. */
#define GEM_NCFGR 0x0004
#define GEM_USRIO 0x000c
+#define GEM_DMACFG 0x0010
#define GEM_HRB 0x0080
#define GEM_HRT 0x0084
#define GEM_SA1B 0x0088
@@ -165,6 +166,10 @@
#define GEM_DBW64 1
#define GEM_DBW128 2
+/* Bitfields in DMACFG. */
+#define GEM_RXBS_OFFSET 16
+#define GEM_RXBS_SIZE 8
+
/* Bitfields in NSR */
#define MACB_NSR_LINK_OFFSET 0
#define MACB_NSR_LINK_SIZE 1
--
1.7.3.4
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