Commit 0f0581b24bd0 ("spi: fsl: Convert to use CS GPIO descriptors") broke the use of the SPISEL_BOOT signal as a chip select on the MPC8309.

pdata->max_chipselect, which becomes master->num_chipselect, must be initialized to take into account the possibility that there's one more chip select in use than the number of GPIO chip selects.

Cc: stable@vger.kernel.org # v5.4+ Cc: Christophe Leroy christophe.leroy@c-s.fr Cc: Linus Walleij linus.walleij@linaro.org Fixes: 0f0581b24bd0 ("spi: fsl: Convert to use CS GPIO descriptors") Signed-off-by: Rasmus Villemoes rasmus.villemoes@prevas.dk --- Longer-term, it might be nicer to introduce a very trivial "gpiochip" with nr_gpios=1, which doesn't really implement neither the "general-purpose" nor the "input" part of the gpio acronym. That's how this ended up being handled in U-Boot, for example:

https://github.com/u-boot/u-boot/commit/3fb22bc2f825ea1b3326edc5b32d711a759a...

But for -stable, this is much simpler.

drivers/spi/spi-fsl-spi.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/spi/spi-fsl-spi.c b/drivers/spi/spi-fsl-spi.c index 299e9870cf58..9494257e1c33 100644 --- a/drivers/spi/spi-fsl-spi.c +++ b/drivers/spi/spi-fsl-spi.c @@ -716,10 +716,11 @@ static int of_fsl_spi_probe(struct platform_device *ofdev) type = fsl_spi_get_type(&ofdev->dev); if (type == TYPE_FSL) { struct fsl_spi_platform_data *pdata = dev_get_platdata(dev); + bool spisel_boot = false; #if IS_ENABLED(CONFIG_FSL_SOC) struct mpc8xxx_spi_probe_info *pinfo = to_of_pinfo(pdata); - bool spisel_boot = of_property_read_bool(np, "fsl,spisel_boot");

+ spisel_boot = of_property_read_bool(np, "fsl,spisel_boot"); if (spisel_boot) { pinfo->immr_spi_cs = ioremap(get_immrbase() + IMMR_SPI_CS_OFFSET, 4); if (!pinfo->immr_spi_cs) @@ -734,10 +735,14 @@ static int of_fsl_spi_probe(struct platform_device *ofdev) * supported on the GRLIB variant. */ ret = gpiod_count(dev, "cs"); - if (ret <= 0) + if (ret < 0) + ret = 0; + if (ret == 0 && !spisel_boot) { pdata->max_chipselect = 1; - else + } else { + pdata->max_chipselect = ret + spisel_boot; pdata->cs_control = fsl_spi_cs_control; + } }

ret = of_address_to_resource(np, 0, &mem);