linux-kernel - Re: [RFC 17/17] clk: zynq: remove call to of_clk

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20130826153329.GE24795@pengutronix.de>
Date:	Mon, 26 Aug 2013 17:33:29 +0200
From:	Steffen Trumtrar <s.trumtrar@...gutronix.de>
To:	Sören Brinkmann <soren.brinkmann@...inx.com>
Cc:	Sebastian Hesselbarth <sebastian.hesselbarth@...il.com>,
	Michal Simek <monstr@...str.eu>,
	Russell King <linux@....linux.org.uk>,
	Arnd Bergmann <arnd@...db.de>,
	Michal Simek <michal.simek@...inx.com>,
	linux-kernel@...r.kernel.org,
	Mike Turquette <mturquette@...aro.org>,
	linux-arm-kernel@...ts.infradead.org
Subject: Re: [RFC 17/17] clk: zynq: remove call to of_clk_init

On Mon, Aug 26, 2013 at 08:16:29AM -0700, Sören Brinkmann wrote:
> On Mon, Aug 26, 2013 at 02:53:35PM +0200, Sebastian Hesselbarth wrote:
> > On 08/26/13 14:07, Steffen Trumtrar wrote:
> > >On Mon, Aug 26, 2013 at 01:15:11PM +0200, Michal Simek wrote:
> > >>I agree with Soren - let's fix the current problem and then when Steffen has patches with syscon
> > >>we can look at them.
> > >>
> > >>If there is any discussion about early syscon registration please let me know.
> > >>
> > >
> > >Where I'm stuck at the moment is: if I map the whole register space to the
> > >parent node, how do I get its mapped address in the clkc?
> > 
> > Steffen,
> > 
> > if slcr is such an essential part of the SoC, you can choose to provide
> > zynq_slcr_readl/writel callbacks. You can then use those callback in the
> > clock driver without knowing the base address. Also, it allows you to
> > hide slcr specific locking details from subsequent drivers using the
> > callbacks.
> 
> I don't think that'll work. The clkc just wraps the cock primitives and
> does not provide a lot of own clock drivers - actually only one. Those
> clock primitives receive an iomapped address for the clock control which
> is then accessed using readl/writel(). So, wrapping all SLCR accesses in
> special accessors would mean to have almost identical reimplementations
> of all used clock primitives, just to replace readl/writel with
> zynq_slcr_write/read. Or is there some way to make this actually work?

This is exactly my understanding, why I can't use a callback here. At least
not for the clkc.

str

-- 
Pengutronix e.K.                           |                             |
Industrial Linux Solutions                 | http://www.pengutronix.de/  |
Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/