Re: [PATCH 2/5] spi: spi-gpio: Rewrite to use GPIO descriptors

[Olof Johansson <olof@xxxxxxxxx>]

On Mon, Jan 01, 2018 at 02:37:46PM +0100, Linus Walleij wrote:
> This converts the bit-banged GPIO SPI driver to looking up and
> using GPIO descriptors to get a handle on GPIO lines for SCK,
> MOSI, MISO and all CS lines.
> 
> All existing board files are converted in one go to keep it all
> consistent. With these conversions I rarely find any interrim
> steps that makes any sense.
> 
> Device tree probing and GPIO handling should work like before
> also after this patch.
> 
> For board files, we stop using controller data to pass the GPIO
> line for chip select, instead we pass this as a GPIO descriptor
> lookup like everything else.
> 
> In some s3c24xx machines the names of the SPI devices were set to
> "spi-gpio" rather than "spi_gpio" which can never have worked, I
> fixed it working (I guess) as part of this patch set. Sometimes
> I wonder how this code got upstream in the first place, it
> obviously is not tested.
> 
> mach-s3c64xx/mach-smartq.c has the same problem and additionally
> defines the *same* GPIO line for MOSI and MISO which is not going
> to be accepted by gpiolib. As the lines were number 1,2,2 I assumed
> it was a typo and use lines 1,2,3. A comment gives awat that line 0
> is chip select though no actual SPI device is provided for the LCD
> supposed to be on this bit-banged SPI bus. I left it intact instead
> of just deleting the bus though.
> 
> Kill off board file code that try to initialize the SPI lines
> to the same values that they will later be set by the spi_gpio
> driver anyways. Given the huge number of weird things in these
> board files I do not think this code is very tested or put in
> with much afterthought anyways.
> 
> Cc: arm@xxxxxxxxxx # Request ACK
> Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx> # Request ACK
> Cc: Sylwester Nawrocki <sylvester.nawrocki@xxxxxxxxx> # S3C stuff
> Cc: Kukjin Kim <kgene.kim@xxxxxxxxxxx> # S3C stuff
> Cc: Ben Dooks <ben-linux@xxxxxxxxx> # S3C Jive
> Cc: Harald Welte <laforge@xxxxxxxxxxxx> # S3C qt2410
> Cc: Manuel Lauss <manuel.lauss@xxxxxxxxx> # MIPS db1000
> Cc: Paul Cercueil <paul@xxxxxxxxxxxxxxx> # JZ4740
> Cc: Anatolij Gustschin <agust@xxxxxxx> # EEPROM hack
> Signed-off-by: Linus Walleij <linus.walleij@xxxxxxxxxx>

Acked-by: Olof Johansson <olof@xxxxxxxxx>


-Olof
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