Re: [PATCH] spi: ti-qspi: use 128 bit transfer mode for writing to flash

From: Vignesh R
Date: Tue Aug 25 2015 - 02:55:09 EST




On 08/20/2015 11:25 PM, Mark Brown wrote:
> On Thu, Aug 20, 2015 at 04:00:59PM +0530, Vignesh R wrote:
>
>> - writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG);
>> + if (count >= QSPI_WLEN_MAX_BYTES) {
>> + u32 *txp = (u32 *)txbuf;
>> +
>> + data = cpu_to_be32(*txp++);
>> + writel(data, qspi->base +
>> + QSPI_SPI_DATA_REG_3);
>> + data = cpu_to_be32(*txp++);
>> + writel(data, qspi->base +
>> + QSPI_SPI_DATA_REG_2);
>> + data = cpu_to_be32(*txp++);
>> + writel(data, qspi->base +
>> + QSPI_SPI_DATA_REG_1);
>> + data = cpu_to_be32(*txp++);
>> + writel(data, qspi->base +
>> + QSPI_SPI_DATA_REG);
>> + xfer_len = QSPI_WLEN_MAX_BYTES;
>> + cmd |= QSPI_WLEN(QSPI_WLEN_MAX_BITS);
>> + } else {
>> + writeb(*txbuf, qspi->base + QSPI_SPI_DATA_REG);
>> + cmd = qspi->cmd | QSPI_WR_SNGL;
>> + xfer_len = wlen;
>> + cmd |= QSPI_WLEN(wlen);
>> + }
>
> It's a bit sad that this isn't able to do a Duff's device type thing and
> only kicks in for the full 128 bit FIFO size, it looks like it could do
> any number of words.
>

Yes, any number of bytes can be transfered (max 16 bytes).
I will try to work on your suggestion. Thanks!

--
Regards
Vignesh
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