Subject: Re: [PATCH] usbnet: smsc95xx: Add device tree input for MAC address

From: Dan Murphy <[email-masked]>
Date: Sun, 6 Oct 2013 12:31:38 -0500

On 10/06/2013 10:05 AM, Ming Lei wrote:
> On Sat, Oct 5, 2013 at 2:25 AM, Dan Murphy <[email-masked]> wrote:
>> If the smsc95xx does not have a valid MAC address stored within
>> the eeprom then a random number is generated.  The MAC can also
>> be set by uBoot but the smsc95xx does not have a way to read this.
>>
>> Create the binding for the smsc95xx so that uBoot can set the MAC
>> and the code can retrieve the MAC from the modified DTB file.
> Suppose there are two smsc95xx usbnet devices connected to usb bus, and
> one is built-in, another is hotplug device, can your patch handle the situation
> correctly?

Look at this line in the patch below

sprintf(of_name, "%s%i", SMSC95XX_OF_NAME, dev->udev->dev.id);

I am appending the dev ID of the device to the of_name here.  As long as init_mac_address is called, the dev.id and the uBoot
entry match then yes.

>> Signed-off-by: Dan Murphy <[email-masked]>
>> ---
>>  Documentation/devicetree/bindings/net/smsc95xx.txt |   17 ++++++++++++++
>>  drivers/net/usb/smsc95xx.c                         |   24 ++++++++++++++++++++
>>  2 files changed, 41 insertions(+)
>>  create mode 100644 Documentation/devicetree/bindings/net/smsc95xx.txt
>>
>> diff --git a/Documentation/devicetree/bindings/net/smsc95xx.txt b/Documentation/devicetree/bindings/net/smsc95xx.txt
>> new file mode 100644
>> index 0000000..4c37280
>> --- /dev/null
>> +++ b/Documentation/devicetree/bindings/net/smsc95xx.txt
>> @@ -0,0 +1,17 @@
>> +* Smart Mixed-Signal Connectivity (SMSC) 95xx Controller
>> +
>> +Required properties:
>> +None
>> +
>> +Optional properties:
>> +- mac-address - Read the mac address that was stored by uBoot
>> +- local-address - Read the mac address that was stored by uBoot
>> +- address - Read the mac address that was stored by uBoot
>> +
>> +Examples:
>> +
>> +smsc0: smsc95xx@0 {
>> +       /* Filled in by U-Boot */
>> +       mac-address = [ 00 00 00 00 00 00 ];
>> +};
>> +
>> diff --git a/drivers/net/usb/smsc95xx.c b/drivers/net/usb/smsc95xx.c
>> index 3f38ba8..baee0bd 100644
>> --- a/drivers/net/usb/smsc95xx.c
>> +++ b/drivers/net/usb/smsc95xx.c
>> @@ -31,6 +31,9 @@
>>  #include <linux/crc32.h>
>>  #include <linux/usb/usbnet.h>
>>  #include <linux/slab.h>
>> +#include <linux/of.h>
>> +#include <linux/of_net.h>
>> +
>>  #include "smsc95xx.h"
>>
>>  #define SMSC_CHIPNAME                  "smsc95xx"
>> @@ -62,6 +65,8 @@
>>  #define SUSPEND_ALLMODES               (SUSPEND_SUSPEND0 | SUSPEND_SUSPEND1 | \
>>                                          SUSPEND_SUSPEND2 | SUSPEND_SUSPEND3)
>>
>> +#define SMSC95XX_OF_NAME       "/smsc95xx@"
>> +
>>  struct smsc95xx_priv {
>>         u32 mac_cr;
>>         u32 hash_hi;
>> @@ -767,6 +772,25 @@ static int smsc95xx_ioctl(struct net_device *netdev, struct ifreq *rq, int cmd)
>>
>>  static void smsc95xx_init_mac_address(struct usbnet *dev)
>>  {
>> +
>> +#ifdef CONFIG_OF
>> +       struct device_node *ap;
>> +       const char *mac = NULL;
>> +       char *of_name = SMSC95XX_OF_NAME;
>> +
>> +       sprintf(of_name, "%s%i", SMSC95XX_OF_NAME, dev->udev->dev.id);
>> +       ap = of_find_node_by_path(of_name);
>> +       if (ap) {
>> +               mac = of_get_mac_address(ap);
>> +               if (is_valid_ether_addr(mac)) {
>> +                       /* Device tree has a mac for this so use that */
>> +                       memcpy(dev->net->dev_addr, mac, ETH_ALEN);
>> +                       netif_dbg(dev, ifup, dev->net, "MAC address read from DTB\n");
>> +                       return;
>> +               }
>> +       }
>> +#endif
>> +
>>         /* try reading mac address from EEPROM */
>>         if (smsc95xx_read_eeprom(dev, EEPROM_MAC_OFFSET, ETH_ALEN,
>>                         dev->net->dev_addr) == 0) {
>> --
>> 1.7.9.5
>>
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>
> Thanks,

-- 
------------------
Dan Murphy

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