Re: [PATCH 0/2] rewrite mtk-quadspi spi-nor driver with spi-mem
From: Chuanhong Guo <hidden>
Date: 2020-02-26 01:31:57
Also in:
linux-devicetree, linux-mediatek, linux-spi, lkml
Hi! On Wed, Feb 26, 2020 at 1:31 AM Rob Herring [off-list ref] wrote:
On Thu, Feb 20, 2020 at 07:58:06AM +0800, Chuanhong Guo wrote:quoted
Hi! On Tue, Feb 18, 2020 at 8:55 PM Mark Brown [off-list ref] wrote:quoted
This is an ABI break so you shouldn't be doing this, if the existing binding works it should continue to work.The missing spi-max-frequency is the only part preventing old device tree to work with this driver. If the goal is to make existing dt binding work, I could patch dt using of_add_property in v2. I saw similar device tree patching for legacy bindings in pinctrl-single driver.
I just noticed that of_add_property isn't a exported symbol, which means that device tree patching isn't possible unless driver is builtin.
You should should really only need 'spi-max-frequency' if the max freq is less than the minimum of the host and device max freq.
But current spi framework forces that a "spi-max-frequency" property is present. [0] Should we patch spi framework then? [0] https://elixir.bootlin.com/linux/latest/source/drivers/spi/spi.c#L1951 -- Regards, Chuanhong Guo _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel