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Re: [PATCH] clk: samsung: exynos5433: use clock_ignore_unused flag for SPI3 related clocks

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Hi Tomasz,

> >> > The SPI 3 bus uses two clocks, a bus clock and an input clock.
> >> > Do not disable the clocks when unused in order to allow access to
> >> > the SPI 3 device.
> >>
> >> If unused, why would access to SPI 3 device needed?
> >
> > because next I will submit a small driver which uses the SPI3.
> > Actually in the exynos5433 boards all the SPI are used but not all
> > the drivers are ported to mainline.
> 
> Then shouldn't the driver request the clocks and enable them? Or I'm
> missing something obvious? :)

the reason is that...

[ from the patch ]

>         GATE(CLK_SCLK_IOCLK_SPI3, "sclk_ioclk_spi3", "ioclk_spi3_clk_in",
> -                       ENABLE_SCLK_PERIC, 20, CLK_SET_RATE_PARENT, 0),
> +                       ENABLE_SCLK_PERIC, 20,
> +                       CLK_IGNORE_UNUSED | CLK_SET_RATE_PARENT, 0),

... the sclk_ioclk_spi3 is new in exynos5433 and there is no
implementation for enabling/disabling that particular clock...

>         GATE(CLK_SCLK_SPI3, "sclk_spi3", "sclk_spi3_peric", ENABLE_SCLK_PERIC,
> -                       18, CLK_SET_RATE_PARENT, 0),
> +                       18, CLK_IGNORE_UNUSED | CLK_SET_RATE_PARENT, 0),

... while in this case your question makes sense, but it depends
on which clock the device (s3c64xx) is requesting (from the DTS).
In any case, I kept it consistent with the SPI1, which falls in
the same case, as in mainline we don't have any DTS for
exynos5433 (yet!).

Thanks,
Andi

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[PATCH] clk: samsung: exynos5433: use clock_ignore_unused flag for  SPI3 related clocks Andi Shyti <andi.shyti@samsung.com> - 2016-06-17 10:20 +0200
  Re: [PATCH] clk: samsung: exynos5433: use clock_ignore_unused flag  for SPI3 related clocks Tomasz Figa <tomasz.figa@gmail.com> - 2016-06-18 16:40 +0200
    Re: [PATCH] clk: samsung: exynos5433: use clock_ignore_unused flag  for SPI3 related clocks Andi Shyti <andi@etezian.org> - 2016-06-19 08:00 +0200
      Re: [PATCH] clk: samsung: exynos5433: use clock_ignore_unused flag  for SPI3 related clocks Tomasz Figa <tomasz.figa@gmail.com> - 2016-06-19 15:50 +0200
        Re: [PATCH] clk: samsung: exynos5433: use clock_ignore_unused flag for  SPI3 related clocks Andi Shyti <andi.shyti@samsung.com> - 2016-06-20 07:50 +0200
          Re: [PATCH] clk: samsung: exynos5433: use clock_ignore_unused flag  for SPI3 related clocks Tomasz Figa <tomasz.figa@gmail.com> - 2016-06-20 11:10 +0200
            Re: [PATCH] clk: samsung: exynos5433: use clock_ignore_unused flag for  SPI3 related clocks Andi Shyti <andi.shyti@samsung.com> - 2016-06-20 12:30 +0200

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