Re: [PATCH v2 00/22] memory: omap-gpmc: mtd: nand: Support GPMC NAND on non-OMAP platforms
From: Roger Quadros
Date: Thu Aug 13 2015 - 03:14:31 EST
On 11/08/15 15:48, Tony Lindgren wrote:
> * Roger Quadros <rogerq@xxxxxx> [150807 02:15]:
>> We do a couple of things in this series which result in
>> cleaner device tree implementation, faster perfomance and
>> multi-platform support. As an added bonus we get new GPI/Interrupt pins
>> for use in the system.
>> - Establish a custom interface between NAND and GPMC driver. This is
>> needed because all of the NAND registers sit in the GPMC register space.
>> Some bits like NAND IRQ are even shared with GPMC.
>> - Remove NAND IRQ handling from omap-gpmc driver, share the GPMC IRQ
>> with the omap2-nand driver and handle NAND IRQ events in the NAND driver.
>> This causes performance increase when using prefetch-irq mode.
>> 30% increase in read, 17% increase in write in prefetch-irq mode.
>> - Clean up device tree support so that omap-gpmc IP and the omap2 NAND
>> driver can be used on non-OMAP platforms. e.g. Keystone.
>> - Implement GPIOCHIP + IRQCHIP for the GPMC WAITPINS. SoCs can contain
>> 2 to 4 of these and most of them would be unused otherwise. It also
>> allows a cleaner implementation of NAND Ready pin status for the NAND driver.
>> - Implement GPIOlib based NAND ready pin checking for OMAP NAND driver.
> Nice job :) Using GPIOCHIP + IRQCHIP allows us to make the GPMC
> using drivers pretty much generic eventually.
>> NOTE: I've only adapted dra7.dtsi and dra7x-evms for this series.
>> I will adapt all other boards when the series is in a shape to be accepted.
> OK. Yeah let's make sure no regressions are caused by this.. We also
> still have the omap3 legacy booting around, have you checked that it
> keeps on working?
I don't have any omap3 board with legacy support with me. I have omap3-beagle
but looks like legacy boot is dropped for it already.
I'll try to revert the patch that drops beagle support and test it on that one.
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