On Thu, Dec 01, 2016 at 11:27:16AM +0100, Romain Perier wrote:
> Changes in v3:
> - Don't enable the fifo mode based on the compatible string, we introduce
> a module parameter "pio_mode". By default this option is set to zero, so
> the fifo mode is enabled. Pass pio_mode=1 to the driver enables the PIO
> mode.
Why? If the hardware supports a more efficient mode of operation it
doesn't seem sensible not to use it.
> - int i;
> + int i, ret = 0;
Coding style - don't combine initialized and non-initalized variables on
one line.
> static int a3700_spi_transfer_one(struct spi_master *master,
> struct spi_device *spi,
> struct spi_transfer *xfer)
> {
> struct a3700_spi *a3700_spi = spi_master_get_devdata(master);
> - int ret = 0;
> + int ret;
>
> a3700_spi_transfer_setup(spi, xfer);
>
> @@ -505,6 +737,151 @@ static int a3700_spi_transfer_one(struct spi_master *master,
> return ret;
> }
This appears to be a random unrelated change, should probably be part of
the initial driver commit.
> +static int a3700_spi_fifo_transfer_one(struct spi_master *master,
> + struct spi_device *spi,
> + struct spi_transfer *xfer)
> +{
> + struct a3700_spi *a3700_spi = spi_master_get_devdata(master);
> + int ret = 0, timeout = A3700_SPI_TIMEOUT;
> + unsigned int nbits = 0;
> + u32 val;
> +
> + a3700_spi_transfer_setup(spi, xfer);
> +
> + a3700_spi->tx_buf = xfer->tx_buf;
> + a3700_spi->rx_buf = xfer->rx_buf;
> + a3700_spi->buf_len = xfer->len;
> +
> + /* SPI transfer headers */
> + a3700_spi_header_set(a3700_spi);
> +
> + if (xfer->tx_buf)
> + nbits = xfer->tx_nbits;
> + else if (xfer->rx_buf)
> + nbits = xfer->rx_nbits;
> +
> + a3700_spi_pin_mode_set(a3700_spi, nbits);
> +
> + if (xfer->rx_buf) {
> + /* Set read data length */
> + spireg_write(a3700_spi, A3700_SPI_IF_DIN_CNT_REG,
> + a3700_spi->buf_len);
> + /* Start READ transfer */
> + val = spireg_read(a3700_spi, A3700_SPI_IF_CFG_REG);
> + val &= ~A3700_SPI_RW_EN;
> + val |= A3700_SPI_XFER_START;
> + spireg_write(a3700_spi, A3700_SPI_IF_CFG_REG, val);
> + } else if (xfer->tx_buf) {
> + /* Start Write transfer */
So this only supports single duplex transfers but there doesn't seem to
be anything that enforces this.
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