[NET] smc91x: prepare for SMC_IO_SHIFT to be a platform configurable variable

Now one can use the following code

  #define SMC_IO_SHIFT	lp->io_shift

to make SMC_IO_SHIFT a variable. This, however, will slightly increase
the CPU overhead and have negative impact on the network performance.
The tradeoff is, this can be specified in the smc91x platform data so
that multiple boards support can be built in a single zImage.

Signed-off-by: Eric Miao <eric.miao@marvell.com>
Acked-by: Nicolas Pitre <nico@cam.org>
Acked-by: Jeff Garzik <jgarzik@pobox.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

1 files changed, 7 insertions, 0 deletions

diff --git a/include/linux/smc91x.h b/include/linux/smc91x.h
index 90434db72db..0dea9459a8e 100644
--- a/include/linux/smc91x.h
+++ b/include/linux/smc91x.h
@@ -7,6 +7,13 @@
 
 #define SMC91X_NOWAIT		(1 << 3)
 
+/* two bits for IO_SHIFT, let's hope later designs will keep this sane */
+#define SMC91X_IO_SHIFT_0	(0 << 4)
+#define SMC91X_IO_SHIFT_1	(1 << 4)
+#define SMC91X_IO_SHIFT_2	(2 << 4)
+#define SMC91X_IO_SHIFT_3	(3 << 4)
+#define SMC91X_IO_SHIFT(x)	(((x) >> 4) & 0x3)
+
 struct smc91x_platdata {
 	unsigned long flags;
 };