Re: [PATCH 4/6] SPI: S3C64XX: Correction for 16,32 bits bus width

[Jassi Brar <jassisinghbrar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>]

On Thu, Sep 9, 2010 at 2:07 PM, Grant Likely <grant.likely@secretlab.ca> wrote:
> On Fri, Sep 03, 2010 at 10:36:54AM +0900, Jassi Brar wrote:
>> We can't do without setting channel and bus width to
>> same size.
>> Inorder to do that, define a new callback to be used
>> to do read/write of appropriate widths.
>>
>> Signed-off-by: Jassi Brar <jassi.brar@samsung.com>
>> ---
>>  drivers/spi/spi_s3c64xx.c |   78 +++++++++++++++++++++++++++++++++++++-------
>>  1 files changed, 65 insertions(+), 13 deletions(-)
>>
>> diff --git a/drivers/spi/spi_s3c64xx.c b/drivers/spi/spi_s3c64xx.c
>> index 39816bb..8aa9f85 100644
>> --- a/drivers/spi/spi_s3c64xx.c
>> +++ b/drivers/spi/spi_s3c64xx.c
>> @@ -174,12 +174,59 @@ struct s3c64xx_spi_driver_data {
>>       unsigned                        state;
>>       unsigned                        cur_mode, cur_bpw;
>>       unsigned                        cur_speed;
>> +     void (*do_xfer)(void *ptr, void *fifo, unsigned sz, bool rd);
>
> Looking at the code; it appears that it would be better to have
> separate read and write transfer hooks.
>
>>  };
>>
>>  static struct s3c2410_dma_client s3c64xx_spi_dma_client = {
>>       .name = "samsung-spi-dma",
>>  };
>>
>> +static void s3c64xx_spi_xfer8(void *ptr, void __iomem *fifo,
>> +             unsigned len, bool read)
>> +{
>> +     u8 *buf = (u8 *)ptr;
>
> ptr is already a void* which makes this an unnecessary cast.
>
>> +     int i = 0;
>> +
>> +     if (read)
>> +             while (i < len)
>> +                     buf[i++] = readb(fifo);
>
> perhaps ioread8_rep() instead of open-coding?  If so, then
> ioread*_rep() and iowrite*_rep() can be used in all these cases.
>
> In fact, the 8, 16 and 32 versions have the same signature and so
> could possibly be used directly without these hooks.

Great idea. I have rather avoided new callbacks and directly used the
ioread*_rep
calls. Also, I had missed setting appropriate bus width while in DMA mode.
Resending this again.
Thanks.

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