From 118aee4dd91cf3c0b9546788ef66b65d3e9e31b1 Mon Sep 17 00:00:00 2001 From: Magnus Damm Date: Fri, 14 Dec 2012 14:54:37 +0900 Subject: clocksource: sh_cmt: Add CMT register layout comment Add a comment about different register layouts supported by the CMT driver. Signed-off-by: Magnus Damm Acked-by: John Stultz Tested-by: Guennadi Liakhovetski Signed-off-by: Simon Horman --- drivers/clocksource/sh_cmt.c | 15 +++++++++++++++ 1 file changed, 15 insertions(+) (limited to 'drivers/clocksource/sh_cmt.c') diff --git a/drivers/clocksource/sh_cmt.c b/drivers/clocksource/sh_cmt.c index 7108963a6ab8..b72b7242125e 100644 --- a/drivers/clocksource/sh_cmt.c +++ b/drivers/clocksource/sh_cmt.c @@ -66,6 +66,21 @@ struct sh_cmt_priv { unsigned long value); }; +/* Examples of supported CMT timer register layouts and I/O access widths: + * + * "16-bit counter and 16-bit control" as found on sh7263: + * CMSTR 0xfffec000 16-bit + * CMCSR 0xfffec002 16-bit + * CMCNT 0xfffec004 16-bit + * CMCOR 0xfffec006 16-bit + * + * "32-bit counter and 16-bit control" as found on sh7372, sh73a0, r8a7740: + * CMSTR 0xffca0000 16-bit + * CMCSR 0xffca0060 16-bit + * CMCNT 0xffca0064 32-bit + * CMCOR 0xffca0068 32-bit + */ + static unsigned long sh_cmt_read16(void __iomem *base, unsigned long offs) { return ioread16(base + (offs << 1)); -- cgit v1.2.3-59-g8ed1b