On Tue, Nov 20, 2018 at 01:28:20AM +0100, Anatolij Gustschin wrote:
> --- a/drivers/spi/Makefile
> +++ b/drivers/spi/Makefile
> @@ -113,6 +113,7 @@ obj-$(CONFIG_SPI_XILINX) += spi-xilinx.o
> obj-$(CONFIG_SPI_XLP) += spi-xlp.o
> obj-$(CONFIG_SPI_XTENSA_XTFPGA) += spi-xtensa-xtfpga.o
> obj-$(CONFIG_SPI_ZYNQMP_GQSPI) += spi-zynqmp-gqspi.o
> +obj-$(CONFIG_SPI_FTDI_MPSSE) += spi-ftdi-mpsse.o
>
> # SPI slave protocol handlers
> obj-$(CONFIG_SPI_SLAVE_TIME) += spi-slave-time.o
Please keep the Makefile sorted.
> +++ b/drivers/spi/spi-ftdi-mpsse.c
> @@ -0,0 +1,673 @@
> +// SPDX-License-Identifier: GPL-2.0
> +/*
> + * FTDI FT232H MPSSE SPI controller driver
Please make the entire comment block here a C++ one so it looks more
consistent.
> + struct gpiod_lookup_table *lookup[13];
This magic number for the size of the lookup table is not good.
> +static void ftdi_spi_chipselect(struct ftdi_spi *priv, struct spi_device *spi,
> + bool value)
> +{
> + int cs = spi->chip_select;
> +
> + dev_dbg(&priv->master->dev, "%s: CS %d, cs mode %d, val %d\n",
> + __func__, cs, (spi->mode & SPI_CS_HIGH), value);
> +
> + gpiod_set_raw_value_cansleep(priv->cs_gpios[cs], value);
> +}
This is just a gpio chip select - can't it be handled by the core chip
select code?
> + remaining = len;
> + do {
> + stride = min_t(size_t, remaining, SZ_64K - 3);
Rather than having a magic number for the buffer size it would be better
to either have a driver specific constant that's used consistently or
just use sizeof() when it's referenced in the code. That way if the
buffer size is changed nothing will get missed.
> + /* Last transfer with cs_change set, stop keeping CS */
> + if (list_is_last(&t->transfer_list, &msg->transfers)) {
> + keep_cs = true;
> + break;
> + }
> + ftdi_spi_chipselect(priv, spi, !(spi->mode & SPI_CS_HIGH));
> + usleep_range(10, 15);
> + ftdi_spi_chipselect(priv, spi, spi->mode & SPI_CS_HIGH);
I'm not clear what this is intended to do? It's overall not clear to me
that the driver needs to use transfer_one_message and not transfer_one,
the latter keeps more of the code in common code.
> + /* Find max. slave chipselect number */
> + num_cs = pd->spi_info_len;
> + for (i = 0; i < num_cs; i++) {
> + if (max_cs < pd->spi_info[i].chip_select)
> + max_cs = pd->spi_info[i].chip_select;
> + }
> +
> + if (max_cs > 12) {
> + dev_err(dev, "Invalid max CS in platform data: %d\n", max_cs);
> + return -EINVAL;
> + }
> + dev_dbg(dev, "CS count %d, max CS %d\n", num_cs, max_cs);
> + max_cs += 1; /* including CS0 */
Why not just size the array based on the platform data?
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