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SubjectRe: [Letux-kernel] [PATCH v2] net: davicom: dm9000: allow to pass MAC address through mac_addr module parameter
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> Am 14.02.2020 um 20:38 schrieb H. Nikolaus Schaller <hns@goldelico.com>:
>
>
>> Am 14.02.2020 um 20:24 schrieb H. Nikolaus Schaller <hns@goldelico.com>:
>>
>>
>>> Am 14.02.2020 um 19:47 schrieb Paul Cercueil <paul@crapouillou.net>:
>>>
>>> Hi Nikolaus,
>>>
>>> What I'd suggest is to write a NVMEM driver for the efuse and retrieve the MAC address cleanly with nvmem_get_mac_address().
>>>
>>> It shouldn't be hard to do (there's already code for it in the non-upstream 3.18 kernel for the CI20) and you remove the dependency on uboot.
>>
>> Interesting approach. I have found this:
>>
>> https://lore.kernel.org/patchwork/patch/868158/
>>
>> but it looks as if it was never finished (I could not locate a V3 or anything mainline?)
>> and and it tries to solve other problems as well.
>>
>> And it looks to be much more complex than my "solution" to the immediate problem.
>>
>> I have to study it to know if I can write a nvmem_get_mac_address().
>
> Another question is how to link this very jz4780 specific code to the generic davicom dm9000 driver?
> And where should the new code live. In some jz4780 specific file or elsewhere?

Ok, got it.

nvmem_get_mac_address() is looking for a nvmem cell "mac-address".

So some jz4780 specific driver must provide such cells.

There aren't many examples but it appears as if arch/arm/mach-davinci/board-da830-evm.c
defines and registers nvmem cells.

But maybe it is not difficult to teach the 2018 driver to provide such cells.

BR and thanks,
Nikolaus


>
>>
>> BR,
>> Nikolaus
>>
>>>
>>> -Paul
>>>
>>>
>>> Le ven., févr. 14, 2020 at 17:07, H. Nikolaus Schaller <hns@goldelico.com> a écrit :
>>>> The MIPS Ingenic CI20 board is shipped with a quite old u-boot
>>>> (ci20-v2013.10 see https://elinux.org/CI20_Dev_Zone). This passes
>>>> the MAC address through dm9000.mac_addr=xx:xx:xx:xx:xx:xx
>>>> kernel module parameter to give the board a fixed MAC address.
>>>> This is not processed by the dm9000 driver which assigns a random
>>>> MAC address on each boot, making DHCP assign a new IP address
>>>> each time.
>>>> So we add a check for the mac_addr module parameter as a last
>>>> resort before assigning a random one. This mechanism can also
>>>> be used outside of u-boot to provide a value through modprobe
>>>> config.
>>>> To parse the MAC address in a new function get_mac_addr() we
>>>> use an copy adapted from the ksz884x.c driver which provides
>>>> the same functionality.
>>>> Signed-off-by: H. Nikolaus Schaller <hns@goldelico.com>
>>>> ---
>>>> drivers/net/ethernet/davicom/dm9000.c | 42 +++++++++++++++++++++++++++
>>>> 1 file changed, 42 insertions(+)
>>>> diff --git a/drivers/net/ethernet/davicom/dm9000.c b/drivers/net/ethernet/davicom/dm9000.c
>>>> index 1ea3372775e6..7402030b0352 100644
>>>> --- a/drivers/net/ethernet/davicom/dm9000.c
>>>> +++ b/drivers/net/ethernet/davicom/dm9000.c
>>>> @@ -1409,6 +1409,43 @@ static struct dm9000_plat_data *dm9000_parse_dt(struct device *dev)
>>>> return pdata;
>>>> }
>>>> +static char *mac_addr = ":";
>>>> +module_param(mac_addr, charp, 0);
>>>> +MODULE_PARM_DESC(mac_addr, "MAC address");
>>>> +
>>>> +static void get_mac_addr(struct net_device *ndev, char *macaddr)
>>>> +{
>>>> + int i = 0;
>>>> + int j = 0;
>>>> + int got_num = 0;
>>>> + int num = 0;
>>>> +
>>>> + while (j < ETH_ALEN) {
>>>> + if (macaddr[i]) {
>>>> + int digit;
>>>> +
>>>> + got_num = 1;
>>>> + digit = hex_to_bin(macaddr[i]);
>>>> + if (digit >= 0)
>>>> + num = num * 16 + digit;
>>>> + else if (':' == macaddr[i])
>>>> + got_num = 2;
>>>> + else
>>>> + break;
>>>> + } else if (got_num) {
>>>> + got_num = 2;
>>>> + } else {
>>>> + break;
>>>> + }
>>>> + if (got_num == 2) {
>>>> + ndev->dev_addr[j++] = (u8)num;
>>>> + num = 0;
>>>> + got_num = 0;
>>>> + }
>>>> + i++;
>>>> + }
>>>> +}
>>>> +
>>>> /*
>>>> * Search DM9000 board, allocate space and register it
>>>> */
>>>> @@ -1679,6 +1716,11 @@ dm9000_probe(struct platform_device *pdev)
>>>> ndev->dev_addr[i] = ior(db, i+DM9000_PAR);
>>>> }
>>>> + if (!is_valid_ether_addr(ndev->dev_addr)) {
>>>> + mac_src = "param";
>>>> + get_mac_addr(ndev, mac_addr);
>>>> + }
>>>> +
>>>> if (!is_valid_ether_addr(ndev->dev_addr)) {
>>>> inv_mac_addr = true;
>>>> eth_hw_addr_random(ndev);
>>>> --
>>>> 2.23.0
>>>
>>>
>>
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>
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