Re: [PATCH v3 1/2] spi: Add Renesas R-Car Gen3 RPC SPI controller driver

[Sergei Shtylyov]

Hello!

On 12/21/2018 04:30 AM, masonccyang@xxxxxxxxxxx wrote:

>> > diff --git a/drivers/spi/spi-renesas-rpc.c b/drivers/spi/spi-renesas-rpc.c
>> > new file mode 100644
>> > index 0000000..cec5669
>> > --- /dev/null
>> > +++ b/drivers/spi/spi-renesas-rpc.c
>> > @@ -0,0 +1,776 @@
>> [...]
>> > +static const struct soc_device_attribute r8a7795es1[] __initconst = {
>>
>>    This __initconst shouldn't be there, it causes a build warning.
>>
>> > +   { .soc_id = "r8a7795", .revision = "ES1.*" },
>>
>>    Wait, the driver doesn't really probe on R8A7795 yet!
> 
> yup, this is for RPC_PHYCNT_STRTIM setting by Marek's comments.
> 
> On H3 ES1.x, the value should be 0, while on others, the value should be 6.
> 
> ES1.x is r8a7795.

   Why care if we don't support H3 yet? Add this when the R8A77950 support is added.

>> > +   { /* sentinel */ }
>> > +};
>> > +
>> > +static void rpc_spi_hw_init(struct rpc_spi *rpc)
>> > +{
>> > +   int strtim;
>> > +   /*
>> > +    * NOTE: The 0x260 are undocumented bits, but they must be set.
>> > +    *   RPC_PHYCNT_STRTIM is strobe timing adjustment bit,
>> > +    *   0x0 : the delay is biggest,
>> > +    *   0x1 : the delay is 2nd biggest,
>> > +    *   On H3 ES1.x, the value should be 0, while on others,
>> > +    *   the value should be 6.
>> > +    */
>> > +   if (soc_device_match(r8a7795es1))
>> > +      strtim = 0;
>> > +   else
>> > +      strtim = 6;
>> [...]
>> > +static const struct of_device_id rpc_spi_of_ids[] = {
>> > +   { .compatible = "renesas,r8a77995-rpc", },
>>
>>    We only support R8A77995 now.
> 
> see above !

   There's difference between R8A77995 and R8A77950, right?

[...]
> thanks & best regards,
> Mason

MBR, Sergei