Subject: [PATCHv4 2/5] net: phy: extend fixed driver with fixed_phy_register()

From: [email-masked] (Florian Fainelli)
Date: Thu, 03 Sep 2015 12:38:19 -0700

On 03/09/15 12:37, Sergei Shtylyov wrote:
> On 09/03/2015 10:20 PM, Sergei Shtylyov wrote:
> 
>>> The existing fixed_phy_add() function has several drawbacks that
>>> prevents it from being used as is for OF-based declaration of fixed
>>> PHYs:
>>>
>>>   * The address of the PHY on the fake bus needs to be passed, while a
>>>     dynamic allocation is desired.
>>>
>>>   * Since the phy_device instantiation is post-poned until the next
>>>     mdiobus scan, there is no way to associate the fixed PHY with its
>>>     OF node, which later prevents of_phy_connect() from finding this
>>>     fixed PHY from a given OF node.
>>>
>>> To solve this, this commit introduces fixed_phy_register(), which will
>>> allocate an available PHY address, add the PHY using fixed_phy_add()
>>> and instantiate the phy_device structure associated with the provided
>>> OF node.
>>>
>>> Signed-off-by: Thomas Petazzoni <[email-masked]>
>>> Acked-by: Florian Fainelli <[email-masked]>
>>> Acked-by: Grant Likely <[email-masked]>
>>> ---
>>>   drivers/net/phy/fixed.c   | 61
>>> +++++++++++++++++++++++++++++++++++++++++++++++
>>>   include/linux/phy_fixed.h | 11 +++++++++
>>>   2 files changed, 72 insertions(+)
>>>
>>> diff --git a/drivers/net/phy/fixed.c b/drivers/net/phy/fixed.c
>>> index e41546d..d60d875 100644
>>> --- a/drivers/net/phy/fixed.c
>>> +++ b/drivers/net/phy/fixed.c
>> [...]
>>> @@ -203,6 +204,66 @@ err_regs:
>> [...]
>>> +int fixed_phy_register(unsigned int irq,
>>> +               struct fixed_phy_status *status,
>>> +               struct device_node *np)
>>> +{
>>> +    struct fixed_mdio_bus *fmb = &platform_fmb;
>>> +    struct phy_device *phy;
>>> +    int phy_addr;
>>> +    int ret;
>>> +
>>> +    /* Get the next available PHY address, up to PHY_MAX_ADDR */
>>> +    spin_lock(&phy_fixed_addr_lock);
>>> +    if (phy_fixed_addr == PHY_MAX_ADDR) {
>>> +        spin_unlock(&phy_fixed_addr_lock);
>>> +        return -ENOSPC;
>>> +    }
>>> +    phy_addr = phy_fixed_addr++;
>>> +    spin_unlock(&phy_fixed_addr_lock);
>>> +
>>> +    ret = fixed_phy_add(PHY_POLL, phy_addr, status);
>>
>>     Was rummaging in the fixed_phy driver and a bug sprang right at
>> me: 'phy'
> 
>    Sorry, s/phy/irq/ of course. Just noticed. :-/

Ok, that makes sense then, and yes, this "irq" argument should have been
passed down to fixed_phy_add(). Might be worth adding a WARN_ON(irq !=
PHY_POLL) just to catch callers that expect something else.

Thanks!
--
Florian