Messages in this thread | | | Subject | Re: [PATCH 3/4] arm: am33xx: DT quirks for am33xx based beaglebone variants | From | Pantelis Antoniou <> | Date | Thu, 19 Feb 2015 20:44:39 +0200 |
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Hi Tony,
> On Feb 19, 2015, at 20:36 , Tony Lindgren <tony@atomide.com> wrote: > > * Pantelis Antoniou <panto@antoniou-consulting.com> [150219 10:32]: >>> On Feb 19, 2015, at 20:16 , Tony Lindgren <tony@atomide.com> wrote: >>> >>> Uhh I don't like the idea of duplicating the i2c-omap.c driver under >>> arch/arm.. And in general we should initialize things later rather >>> than earlier. >>> >>> What's stopping doing these quirk checks later on time with just >>> a regular device driver, something like drivers/misc/bbone-quirks.c? >>> >> >> We have no choice; we are way early in the boot process, right after >> the device tree unflattening step. > > To me it seems the dt patching part should be done with minimal > code before any driver like features.. >
The way it’s done right now is with minimal code. Reading the EEPROM is required.
>> I’ve toyed with the idea of using early platform devices but the omap-i2c driver >> would need some tender love and care to make it work, and I didn’t want to get >> bogged down with i2c driver details at this point. > > ..so how about just parse a kernel cmdline for the quirks to apply > based on a version string or similar? That can be easily populated > by u-boot or set manually with setenv. > > That leaves out the need for tinkering with i2c super early in > the kernel for revision detection. >
You assume there’s going to be a bootloader…
> Regards, > > Tony
Regards
— Pantelis
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