Hi Leela,
On Thu, Oct 10, 2013 at 5:36 PM, Leela Krishna Amudala
<leelakrishna.a@xxxxxxxxx> wrote:
> Hi Rajeshwari,
>
> On Thu, Oct 10, 2013 at 4:11 PM, Rajeshwari S Shinde
> <rajeshwari.s@xxxxxxxxxxx> wrote:
>> This patch enables word transfer for s3c64xx spi driver.
>> User can set bits_per_word to 32 before calling spi_setup,
>> which would enable the word transfer mode.
>>
>> Signed-off-by: Rajeshwari S Shinde <rajeshwari.s@xxxxxxxxxxx>
>> ---
>> Chnages in V2:
>> - Reduced the call for s3c64xx_spi_config
>> drivers/spi/spi-s3c64xx.c | 24 +++++++++++++++++-------
>> 1 file changed, 17 insertions(+), 7 deletions(-)
>>
>> diff --git a/drivers/spi/spi-s3c64xx.c b/drivers/spi/spi-s3c64xx.c
>> index 512b889..d1b0a2b 100644
>> --- a/drivers/spi/spi-s3c64xx.c
>> +++ b/drivers/spi/spi-s3c64xx.c
>> @@ -498,6 +498,17 @@ static void enable_datapath(struct s3c64xx_spi_driver_data *sdd,
>> chcfg = readl(regs + S3C64XX_SPI_CH_CFG);
>> chcfg &= ~S3C64XX_SPI_CH_TXCH_ON;
>>
>> + if(sdd->cur_bpw == 32) {
>> + /* For word transfer we need to swap bytes */
>> + u32 swapcfg = (S3C64XX_SPI_SWAP_TX_EN | S3C64XX_SPI_SWAP_TX_BYTE |
>> + S3C64XX_SPI_SWAP_TX_HALF_WORD |
>> + S3C64XX_SPI_SWAP_RX_EN |
>> + S3C64XX_SPI_SWAP_RX_BYTE |
>> + S3C64XX_SPI_SWAP_RX_HALF_WORD);
>> + writel(swapcfg, regs + S3C64XX_SPI_SWAP_CFG);
>
> In s3c64xx_spi_probe() function
> sdd->cur_bpw is hard coded to 8
By default sdd->cur_bpw is set to 8 bits transfer.
>
> is there any provision somehow to configure cur_bpw to 32 ?
The user can set bits_per_word to 32 later as per his requirement.
>
> wouldn't 16 bits per word transfers also need swapping?
This patch is tested for Word transfer.
>
> Best Wishes,
> Leela Krishna.
>
>> + } else
>> + writel(0, regs + S3C64XX_SPI_SWAP_CFG);
>> +
>> if (dma_mode) {
>> chcfg &= ~S3C64XX_SPI_CH_RXCH_ON;
>> } else {
>> @@ -905,13 +916,12 @@ static int s3c64xx_spi_transfer_one_message(struct spi_master *master,
>> bpw = xfer->bits_per_word;
>> speed = xfer->speed_hz ? : spi->max_speed_hz;
>>
>> - if (xfer->len % (bpw / 8)) {
>> - dev_err(&spi->dev,
>> - "Xfer length(%u) not a multiple of word size(%u)\n",
>> - xfer->len, bpw / 8);
>> - status = -EIO;
>> - goto out;
>> - }
>> + /*
>> + * Enable byte tranfer if transfer length not a multiple of
>> + * word size
>> + */
>> + if (xfer->len % (bpw / 8))
>> + bpw = 8;
>>
>> if (bpw != sdd->cur_bpw || speed != sdd->cur_speed) {
>> sdd->cur_bpw = bpw;
>> --
>> 1.7.12.4
>>
>> --
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--
Regards,
Rajeshwari Shinde
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