[U-Boot] smc911x runtime detection (was: TI: OMAP3: Overo Tobi ethernet support)

[Dirk Behme <dirk.behme@googlemail.com>]

Olof Johansson wrote:
> Add setup for ethernet on Tobi, allowing kernel/ramdisk to be loaded
> over tftp.
> 
> Based on the omap3 evm code. I added a new highlevel define for Tobi
> to avoid having it dependent on CMD_NET (which would seem backward in
> this case).

First: This is only a request for comment for possible future 
improvement. It doesn't ask for any changes in this patch or is any 
nack. Now to the content ;)

It seems that Steve found a way for runtime detection of smc911x 
making CONFIG_OMAP3_OVERO_TOBI more or less obsolete (from [1]) :

-- cut --
--- git/include/configs/omap3_overo.h-orig	2009-09-17 
13:06:08.000000000 -0700
+++ git/include/configs/omap3_overo.h	2009-09-17 13:06:49.000000000 -0700
@@ -29,7 +29,7 @@
  #define CONFIG_OMAP34XX		1	/* which is a 34XX */
  #define CONFIG_OMAP3430		1	/* which is in a 3430 */
  #define CONFIG_OMAP3_OVERO	1	/* working with overo */
-//#define CONFIG_OMAP3_OVERO_TOBI	1	/* overo mounted on tobi */
+#define CONFIG_OMAP3_OVERO_TOBI	1	/* overo mounted on tobi */

  #include <asm/arch/cpu.h>	/* get chip and board defs */
  #include <asm/arch/omap3.h>
--- git/drivers/net/smc911x.c-orig	2009-09-21 13:28:25.000000000 -0700
+++ git/drivers/net/smc911x.c	2009-09-21 13:29:53.000000000 -0700
@@ -253,6 +253,12 @@ int smc911x_initialize(u8 dev_num, int b

  	dev->iobase = base_addr;

+	/* test to see if chip is present (-1 if not) */
+	if (smc911x_reg_read(dev, MAC_CSR_CMD) == -1) {
+		free(dev);
+		return 0;
+	}
+
  	addrh = smc911x_get_mac_csr(dev, ADDRH);
  	addrl = smc911x_get_mac_csr(dev, ADDRL);
  	dev->enetaddr[0] = addrl;
-- cut --

But this needs some change in smc911x.c driver. Maybe someone likes to 
comment (Ben?).

Best regards

Dirk

[1] 
http://www.sakoman.net/cgi-bin/gitweb.cgi?p=openembedded.git;a=blob;f=recipes/u-boot/u-boot-omap3-git/smsc911x.patch;h=0d71b75727904cb59c88d523794c1d2699127cb2;hb=5965063dcfc396b3ef2f0891b54f05cf8f1ea08e