@@ -728,8 +728,18 @@ static int of_fsl_spi_probe(struct platform_device *ofdev)
}
}
#endif
-
- pdata->cs_control = fsl_spi_cs_control;
+ /*
+ * Handle the case where we have one hardwired (always selected)
+ * device on the first "chipselect". Else we let the core code
+ * handle any GPIOs or native chip selects and assign the
+ * appropriate callback for dealing with the CS lines. This isn't
+ * supported on the GRLIB variant.
+ */
+ ret = gpiod_count(dev, "cs");
+ if (ret <= 0)
+ pdata->max_chipselect = 1;
+ else
+ pdata->cs_control = fsl_spi_cs_control;
}
ret = of_address_to_resource(np, 0, &mem);
The Freescale MPC8xxx had a special quirk for handling a single hardwired chipselect, the case when we're using neither GPIO nor native chip select: when inspecting the device tree and finding zero "cs-gpios" on the device node the code would assume we have a single hardwired chipselect that leaves the device always selected. This quirk is not handled by the new core code, so we need to check the "cs-gpios" explicitly in the driver and set pdata->max_chipselect = 1 which will later fall through to the SPI master ->num_chipselect. Make sure not to assign the chip select handler in this case: there is no handling needed since the chip is always selected, and this is what the old code did as well. Cc: Christophe Leroy <christophe.leroy@c-s.fr> Reported-by: Christophe Leroy <christophe.leroy@c-s.fr> Fixes: 0f0581b24bd0 ("spi: fsl: Convert to use CS GPIO descriptors") Signed-off-by: Linus Walleij <linus.walleij@linaro.org> --- ChangeLog v1->v2: - Reordered patches. - Expanded comment a bit. --- drivers/spi/spi-fsl-spi.c | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) -- 2.23.0