Hello,
Le 05/12/2016 à 14:37, Mark Brown a écrit :
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.
That's just that our customer want to keep both modes, this is why I
decided to use the more efficient mode by default and disable it via a
module parameter. Previously the more efficient mode was always enabled,
based on the "compatible string" of the DT (the PIO mode was simply
useless in this case and dead code)
- int i;
+ int i, ret = 0;
Coding style - don't combine initialized and non-initalized variables on
one line.
Ok
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.
Good catch
+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.
A flag or a capability, typically? I will investigate
Thanks,
Romain
--
Romain Perier, Free Electrons
Embedded Linux and Kernel engineering
http://free-electrons.com
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