[U-Boot] [PATCH v1 20/41] net: mvpp2: handle register mapping and access for PPv2.2

[Stefan Roese]

On 21.03.2017 18:33, Joe Hershberger wrote:
> On Tue, Mar 21, 2017 at 9:27 AM, Stefan Roese <sr at denx.de> wrote:
>> From: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
>>
>> This commit adjusts the mvpp2 driver register mapping and access logic
>> to support PPv2.2, to handle a number of differences.
>>
>> Due to how the registers are laid out in memory, the Device Tree binding
>> for the "reg" property is different:
>>
>> - On PPv2.1, we had a first area for the common registers, and then one
>>   area per port.
>>
>> - On PPv2.2, we have a first area for the common registers, and a
>>   second area for all the per-ports registers.
>>
>> In addition, on PPv2.2, the area for the common registers is split into
>> so-called "address spaces" of 64 KB each. They allow to access the same
>> registers, but from different CPUs. Hence the introduction of cpu_base[]
>> in 'struct mvpp2', and the modification of the mvpp2_write() and
>> mvpp2_read() register accessors. For PPv2.1, the compatibility is
>> preserved by using an "address space" size of 0.
>>
>> Changed by Stefan for U-Boot:
>> Since we don't support multiple CPUs in U-Boot, I've removed all the
>> code, macros and variables introduced in the Linux patch version for this.
>>
>> Signed-off-by: Thomas Petazzoni <thomas.petazzoni at free-electrons.com>
>> Signed-off-by: Stefan Roese <sr at denx.de>
>
> Acked-by: Joe Hershberger <joe.hershberger at ni.com>
>
>> ---
>>
>>  drivers/net/mvpp2.c | 39 +++++++++++++++++++++++++++++++--------
>>  1 file changed, 31 insertions(+), 8 deletions(-)
>>
>> diff --git a/drivers/net/mvpp2.c b/drivers/net/mvpp2.c
>> index c297097c3a..1b6e5586c0 100644
>> --- a/drivers/net/mvpp2.c
>> +++ b/drivers/net/mvpp2.c
>> @@ -342,6 +342,9 @@ do {                                                                        \
>>  #define      MVPP2_GMAC_TX_FIFO_MIN_TH_MASK(v) (((v) << 6) & \
>>                                         MVPP2_GMAC_TX_FIFO_MIN_TH_ALL_MASK)
>>
>> +#define MVPP22_PORT_BASE                       0x30e00
>> +#define MVPP22_PORT_OFFSET                     0x1000
>> +
>>  #define MVPP2_CAUSE_TXQ_SENT_DESC_ALL_MASK     0xff
>>
>>  /* Descriptor ring Macros */
>> @@ -702,6 +705,7 @@ struct mvpp2 {
>>         /* Shared registers' base addresses */
>>         void __iomem *base;
>>         void __iomem *lms_base;
>> +       void __iomem *iface_base;
>
> Curious why this is a new variable instead of reusing the existing
> lms_base, but I suspect it was something needed for the multi-cpu case
> that Stefan removed and here all by itself, the change looks odd.
> Still probably better to keep it closer to the Linux version.

Yes, this was exactly my reasoning.

Thanks,
Stefan