From mboxrd@z Thu Jan 1 00:00:00 1970 From: k.kozlowski@samsung.com (Krzysztof Kozlowski) Date: Thu, 04 Jun 2015 11:04:18 +0900 Subject: [PATCH 11/11] dt: Exynos: add Snow SPI NOR node. In-Reply-To: <3234c12c90eabbeeb6d33604a324231937e309ec.1433364398.git.hramrach@gmail.com> References: <3234c12c90eabbeeb6d33604a324231937e309ec.1433364398.git.hramrach@gmail.com> Message-ID: <556FB222.2070406@samsung.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 04.06.2015 06:26, Michal Suchanek wrote: > The Snow has onboard SPI NOR flash which contains the bootloader. > > Add DT node for this flash chip. The flash is rated 133MHz but the pl330 > controller can transfer only up to 128 bytes at this speed so use more > conservative settings. Even at 40MHz pl330 can transfer at most 64k with > the current driver. > > Signed-off-by: Michal Suchanek > --- > arch/arm/boot/dts/exynos5250-snow.dts | 12 ++++++++++++ > 1 file changed, 12 insertions(+) > > diff --git a/arch/arm/boot/dts/exynos5250-snow.dts b/arch/arm/boot/dts/exynos5250-snow.dts > index 1fa72cf..38e4cda 100644 > --- a/arch/arm/boot/dts/exynos5250-snow.dts > +++ b/arch/arm/boot/dts/exynos5250-snow.dts > @@ -691,6 +691,18 @@ > num-cs = <1>; > cs-gpios = <&gpa2 5 0>; > status = "okay"; > + flash: m25p80 at 0 { The indentation looks odd. This should be at the same level as "status". > + #address-cells = <1>; > + #size-cells = <1>; > + compatible = "jedec,spi-nor"; > + reg = <0>; > + spi-max-frequency = <40000000>; So actually you wanted 133 MHz but as a workaround for DMA issue you use 40 MHz, right? Could you add here a small TODO note in comment about it? Best regards, Krzysztof