Messages in this thread | | | Date | Wed, 12 Mar 2014 12:51:28 +0100 | From | Michal Simek <> | Subject | Re: [PATCH 3/7] ARM: zynq: Hang iomapped slcr address on device_node |
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On 03/11/2014 10:26 PM, Olof Johansson wrote: > On Mon, Jan 6, 2014 at 6:36 AM, Michal Simek <michal.simek@xilinx.com> wrote: >> From: Steffen Trumtrar <s.trumtrar@pengutronix.de> >> >> For later usage by zynq clk driver. >> >> Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de> >> Signed-off-by: Michal Simek <michal.simek@xilinx.com> >> --- >> arch/arm/mach-zynq/slcr.c | 2 ++ >> 1 file changed, 2 insertions(+) >> >> diff --git a/arch/arm/mach-zynq/slcr.c b/arch/arm/mach-zynq/slcr.c >> index 9746de7..2891dcf 100644 >> --- a/arch/arm/mach-zynq/slcr.c >> +++ b/arch/arm/mach-zynq/slcr.c >> @@ -121,6 +121,8 @@ int __init zynq_early_slcr_init(void) >> BUG(); >> } >> >> + np->data = (__force void *)zynq_slcr_base; > > > This is quite unusual, we normally remap again if needed. Is there a > reason you can't just have the driver request the resource and map it > like most other ones do?
I took this patch from Steffen because remapping slcr again in clock driver is another mapping for the same IP. Use one ioremap region seems to me better if there is a way. Of course if this is strictly prohibited we can do another mapping in clock driver.
Here is the RFC I have sent after my discussion with Arnd that we should use early syscon initialization and regmap. This is just RFC to show slcr cleaning up. http://permalink.gmane.org/gmane.linux.kernel/1651213 (Here is broken CLK part because clk subsystem uses clk_readl/clk_writel - changing this is discussed in other threads)
From v1 - regmap device separation was applied by Mark git://git.kernel.org/pub/scm/linux/kernel/git/broonie/regmap.git tags/nodev
From v2 - "mfd: syscon: Support early initialization" I expected to get any comment from Arnd but I will respin this based on Lee's comments
To summarize this for future I would like to use access with regmap with one ioremap.
Thanks, Michal
-- Michal Simek, Ing. (M.Eng), OpenPGP -> KeyID: FE3D1F91 w: www.monstr.eu p: +42-0-721842854 Maintainer of Linux kernel - Microblaze cpu - http://www.monstr.eu/fdt/ Maintainer of Linux kernel - Xilinx Zynq ARM architecture Microblaze U-BOOT custodian and responsible for u-boot arm zynq platform
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