The MII speed calculation was based on the CPU clock (ppc_proc_freq),
but for MPC512x we must use the bus clock instead.
This patch makes it use the correct clock and makes sure we don't
clobber reserved bits in the MII_SPEED register.
Signed-off-by: Wolfgang Denk <w...@denx.de>
Cc: Grant Likely <grant.lik...@secretlab.ca>
Cc: Kumar Gala <ga...@kernel.crashing.org>
Cc: <net...@vger.kernel.org>
---
Note 1: This patch is a rewrite of a previous posting:
http://patchwork.ozlabs.org/patch/28584/
Note 2: Function mpc5xxx_get_mii_speed() was introduced for re-use
in a later patch to drivers/net/fec_mpc52xx.c and
drivers/net/fec_mpc52xx_phy.c, which also contain code to
calculate the MII speed without taking care to check for
overflow or to write only the bits that belong to the
MII_SPEED field when setting the MII speed.
arch/powerpc/sysdev/mpc5xxx_clocks.c | 37 ++++++++++++++++++++++++++++++++++
drivers/net/fs_enet/mii-fec.c | 13 +++++++++--
2 files changed, 47 insertions(+), 3 deletions(-)
diff --git a/arch/powerpc/sysdev/mpc5xxx_clocks.c
b/arch/powerpc/sysdev/mpc5xxx_clocks.c
index 34e12f9..e26d12b 100644
--- a/arch/powerpc/sysdev/mpc5xxx_clocks.c
+++ b/arch/powerpc/sysdev/mpc5xxx_clocks.c
@@ -31,3 +31,40 @@ mpc5xxx_get_bus_frequency(struct device_node *node)
return p_bus_freq ? *p_bus_freq : 0;
}
EXPORT_SYMBOL(mpc5xxx_get_bus_frequency);
+
+/**
+ * mpc5xxx_get_mii_speed - Get the MII_SPEED value
+ * @node: device node
+ *
+ * Returns the MII_SPEED value for MPC512x and MPC52xx systems.
+ * The value gets computed such that the resulting MDC frequency
+ * is 2.5 MHz or lower.
+ */
+
+int
+mpc5xxx_get_mii_speed(struct of_device *ofdev)
+{
+ unsigned int clock, speed;
+
+ clock = mpc5xxx_get_bus_frequency(ofdev->node);
+
+ if (!clock) {
+ dev_err(&ofdev->dev, "could not determine IPS/IPB clock\n");
+ return -ENODEV;
+ }
+
+ /* scale for a MII clock <= 2.5 MHz */
+ speed = (clock + 2499999) / 2500000;
+
+ /* only 6 bits available for MII speed */
+ if (speed > 0x3F) {
+ speed = 0x3F;
+ dev_err(&ofdev->dev,
+ "MII clock (%d MHz) exceeds max (2.5 MHz)\n",
+ clock / speed);
+ }
+
+ /* Field is in bits 25:30 of MII_SPEED register */
+ return speed << 1;
+}
+EXPORT_SYMBOL(mpc5xxx_get_mii_speed);
diff --git a/drivers/net/fs_enet/mii-fec.c b/drivers/net/fs_enet/mii-fec.c
index 75a0999..a28d39f 100644
--- a/drivers/net/fs_enet/mii-fec.c
+++ b/drivers/net/fs_enet/mii-fec.c
@@ -36,6 +36,7 @@
#include <asm/pgtable.h>
#include <asm/irq.h>
#include <asm/uaccess.h>
+#include <asm/mpc5xxx.h>
#include "fs_enet.h"
#include "fec.h"
@@ -103,7 +104,6 @@ static int fs_enet_fec_mii_reset(struct mii_bus *bus)
static int __devinit fs_enet_mdio_probe(struct of_device *ofdev,
const struct of_device_id *match)
{
- struct device_node *np = NULL;
struct resource res;
struct mii_bus *new_bus;
struct fec_info *fec;
@@ -133,13 +133,20 @@ static int __devinit fs_enet_mdio_probe(struct of_device
*ofdev,
if (!fec->fecp)
goto out_fec;
- fec->mii_speed = ((ppc_proc_freq + 4999999) / 5000000) << 1;
+ if (of_device_is_compatible(ofdev->node, "fsl,mpc5121-fec-mdio")) {
+ i = mpc5xxx_get_mii_speed(ofdev);
+ if (i < 0)
+ goto out_unmap_regs;
+ fec->mii_speed = i;
+ } else {
+ fec->mii_speed = ((ppc_proc_freq + 4999999) / 5000000) << 1;
+ }
setbits32(&fec->fecp->fec_r_cntrl, FEC_RCNTRL_MII_MODE);
setbits32(&fec->fecp->fec_ecntrl, FEC_ECNTRL_PINMUX |
FEC_ECNTRL_ETHER_EN);
out_be32(&fec->fecp->fec_ievent, FEC_ENET_MII);
- out_be32(&fec->fecp->fec_mii_speed, fec->mii_speed);
+ clrsetbits_be32(&fec->fecp->fec_mii_speed, 0x7E, fec->mii_speed);
new_bus->phy_mask = ~0;
new_bus->irq = kmalloc(sizeof(int) * PHY_MAX_ADDR, GFP_KERNEL);
--
1.6.0.6
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