[PATCH 1/2] spi: imx: set correct chip_select in platform setup
shawnguo at kernel.org
Mon Mar 20 00:38:16 PDT 2017
On Fri, Mar 17, 2017 at 03:03:02PM +1000, Greg Ungerer wrote:
> Some platform based configuration setup of spi-imx SPI devices does
> not set the "chip_select" to the actual hardware chip select used.
> This works because the cs_gpio mapping that is associated with this
> platform setup maps the chip_select offset used to the appropriate
> hardware chip select. The spi-imx driver uses the chip_select as an
> index into the cs_gpio array and ultimately gets the correct hardware
> chip select for its hardware setup.
> The motivation is to be able to eventually modify the spi-imx code to
> use the "chip_select" directly for harwdare setup instead of indirectly
> via the cs_gpio mapping array.
> This change only affects platforms using the hardware chip select
> addressing method for their SPI devices (sometimes called native chip
> select). The majority of devices using the spi-imx driver use the GPIO
> addressing method.
> The change to use the correct "chip_select" is strait forward. But the
> cs_gpio mapping arrary also needs to be modifed to match that change. In
> simple terms the cs_gpio mapping should always have the hardware chip
> select number at its same index offset.
> There is no functional change with these patches. The three affected
> platforms should work exactly as before. However I don't have any of
> these platforms (or access to them) and so I can't test them. So this
> patch is compile tested only.
> Signed-off-by: Greg Ungerer <gerg at linux-m68k.org>
The subject prefix should be 'ARM: imx: ...'.
Since the patch can go independently, I fix up the prefix and applied
the patch. Thanks.
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