| Message ID | 549018EC.8020207@ti.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Tue, Dec 16, 2014 at 05:05:08PM +0530, Lokesh Vutla wrote: > Is this applicable for OMAP5 also? > If not can you drop omap5 from $subject? DRA7xx = OMAP57xx, which to me is an omap5. Isn't it? And I haven't been able to get a manual for the omap54xx to confirm it, although it seems it does not apply to the omap54xx from what I have been able to gather indirectly. arch_timer_freq = (rate / den) * num; If I do this with the workaround I get: 20000000 / 75 * 244 = 6147525 where as 20000000 * 244 / 75 = 6147540 best value would be 6147541 with proper rounding. In the normal case the worst case is: 26000000 * 384 = 9984000000 That is too big for 32 bits. Now what could be done is prescale by 4 to make the worst case still fit in 32 bits while doing the multiplication before the division, so like this: arch_timer_freq = ((rate / 4) * num / den ) * 4; That gives the same result in all cases including the errata case for the dra7xx at 20MHz and 27MHz. It is off by 3 in the 19.2MHz case though which isn't so nice. Would that be more acceptable? I think having the arch_timer_freq calculated for the errata case seperately from the normal case is cleaner looking compared to that mess and gives a better result for the 19.2MHz case.
On 12/16/2014 10:16 AM, Lennart Sorensen wrote: > On Tue, Dec 16, 2014 at 05:05:08PM +0530, Lokesh Vutla wrote: >> Is this applicable for OMAP5 also? >> If not can you drop omap5 from $subject? > > DRA7xx = OMAP57xx, which to me is an omap5. Isn't it? *AM*57xx is not *OMAP*57xx -> there is no OMAP57xx. AM57xx and DRA7xx are in the same generation of processors and is derivative technology (not the same) as OMAP5432/OMAP5430. We have been using DRA7 as a generic terminology to indicate AM57xx/DRA7 family of processors.
On Tue, Dec 16, 2014 at 01:56:16PM -0600, Nishanth Menon wrote: > *AM*57xx is not *OMAP*57xx -> there is no OMAP57xx. Oh OK. Thanks for clearing that up. > AM57xx and DRA7xx are in the same generation of processors and is > derivative technology (not the same) as OMAP5432/OMAP5430. > > We have been using DRA7 as a generic terminology to indicate > AM57xx/DRA7 family of processors. I will drop omap5 from the subject for the next version then since it seems clear that the omap5 does not have this problem.
diff --git a/arch/arm/mach-omap2/control.h b/arch/arm/mach-omap2/control.h index a3c0133..a80ac2d 100644 --- a/arch/arm/mach-omap2/control.h +++ b/arch/arm/mach-omap2/control.h @@ -286,6 +286,10 @@ #define OMAP5XXX_CONTROL_STATUS 0x134 #define OMAP5_DEVICETYPE_MASK (0x7 << 6) +/* DRA7XX CONTROL CORE BOOTSTRAP */ +#define DRA7_CTRL_CORE_BOOTSTRAP 0x6c4 +#define DRA7_SPEEDSELECT_MASK (0x3 << 8) + /* * REVISIT: This list of registers is not comprehensive - there are more * that should be added. diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c index fb0cb2b..84aadae 100644 --- a/arch/arm/mach-omap2/timer.c +++ b/arch/arm/mach-omap2/timer.c @@ -54,6 +54,7 @@ #include "soc.h" #include "common.h" +#include "control.h" #include "powerdomain.h" #include "omap-secure.h" @@ -545,6 +546,16 @@ static void __init realtime_counter_init(void) break; } + if (soc_is_dra7xx()) { + reg = omap_ctrl_readl(DRA7_CTRL_CORE_BOOTSTRAP); + reg = reg & DRA7_SPEEDSELECT_MASK; + + if (reg) { + num = 75; + den = 244; + } + } + /* Program numerator and denumerator registers */ reg = readl_relaxed(base + INCREMENTER_NUMERATOR_OFFSET) & NUMERATOR_DENUMERATOR_MASK;