-----Original Message-----
From: Bhushan Bharat-R65777
Sent: Wednesday, September 25, 2013 2:23 PM
To: Wang Dongsheng-B40534; Wood Scott-B07421
Cc: linuxppc-dev@lists.ozlabs.org; Wang Dongsheng-B40534
Subject: RE: [PATCH v4 4/4] powerpc/85xx: add sysfs for pw20 state and
altivec idle
=20
=20
=20

quoted

-----Original Message-----
From: Linuxppc-dev [mailto:linuxppc-dev-
bounces+bharat.bhushan=3Dfreescale.com@lists.ozlabs.org] On Behalf Of
bounces+Dongsheng
Wang
Sent: Tuesday, September 24, 2013 2:59 PM
To: Wood Scott-B07421
Cc: linuxppc-dev@lists.ozlabs.org; Wang Dongsheng-B40534
Subject: [PATCH v4 4/4] powerpc/85xx: add sysfs for pw20 state and
altivec idle

From: Wang Dongsheng <redacted>

Add a sys interface to enable/diable pw20 state or altivec idle, and
control the wait entry time.

Enable/Disable interface:
0, disable. 1, enable.
/sys/devices/system/cpu/cpuX/pw20_state
/sys/devices/system/cpu/cpuX/altivec_idle

Set wait time interface:(Nanosecond)
/sys/devices/system/cpu/cpuX/pw20_wait_time
/sys/devices/system/cpu/cpuX/altivec_idle_wait_time
Example: Base on TBfreq is 41MHZ.
1~47(ns): TB[63]
48~95(ns): TB[62]
96~191(ns): TB[61]
192~383(ns): TB[62]
384~767(ns): TB[60]
...

Signed-off-by: Wang Dongsheng <redacted>
---
*v4:
Move code from 85xx/common.c to kernel/sysfs.c.

Remove has_pw20_altivec_idle function.

Change wait "entry_bit" to wait time.

 arch/powerpc/kernel/sysfs.c | 291
++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 291 insertions(+)

diff --git a/arch/powerpc/kernel/sysfs.c b/arch/powerpc/kernel/sysfs.c
index 27a90b9..23fece6 100644
--- a/arch/powerpc/kernel/sysfs.c
+++ b/arch/powerpc/kernel/sysfs.c

@@ -85,6 +85,279 @@ __setup("smt-snooze-delay=3D",

setup_smt_snooze_delay);

 #endif /* CONFIG_PPC64 */

+#ifdef CONFIG_FSL_SOC
+#define MAX_BIT		63
+
+static u64 pw20_wt;
+static u64 altivec_idle_wt;
+
+static unsigned int get_idle_ticks_bit(u64 ns) {
+	u64 cycle;
+
+	cycle =3D div_u64(ns, 1000 / tb_ticks_per_usec);

=20
When tb_ticks_per_usec  > 1000 (timebase frequency > 1GHz) then this will
always be ns, which is not correct, no?
=20

"1000 / tb_ticks_per_usec" means nsec_ticks_per_tb

If timebase frequency > 1GHz, this should be "tb_ticks_per_usec / 1000" and=
 to get tb_ticks_per_nsec.
This should be changed to "cycle =3D ns * tb_ticks_per_nsec;"

But at present we do not have such a platform that timebase frequency more =
than 1GHz. And I think it is not need to support such a situation. Because =
we have no environment to test it.

If later there will be more than 1GHZ platform at that time to add this sup=
port.

Thanks.

-dongsheng