On Apr 17, 2008, at 5:47 PM, Anton Vorontsov wrote:
On Thu, Apr 17, 2008 at 11:28:32PM +0400, Anton Vorontsov wrote:
GTM stands for General-purpose Timers Module and able to generate
timer{1,2,3,4} interrupts. These timers are used by the drivers that
need time precise interrupts (like for USB transactions scheduling
for
the Freescale USB Host controller as found in some QE and CPM chips),
or these timers could be used as wakeup events from the CPU deep-
sleep
mode.
Things unimplemented:
1. Cascaded (32 bit) timers (1-2, 3-4).
This is straightforward to implement when needed, two timers should
be marked as "requested" and configured as appropriate.
2. Super-cascaded (64 bit) timers (1-2-3-4).
This is also straightforward to implement when needed, all timers
should be marked as "requested" and configured as appropriate.
Signed-off-by: Anton Vorontsov <[EMAIL PROTECTED]>
---
Documentation/powerpc/booting-without-of.txt | 32 +++-
arch/powerpc/Kconfig | 5 +
arch/powerpc/sysdev/Makefile | 1 +
arch/powerpc/sysdev/fsl_gtm.c | 362 ++++++++++++++++
++++++++++
include/asm-powerpc/fsl_gtm.h | 108 ++++++++
5 files changed, 507 insertions(+), 1 deletions(-)
create mode 100644 arch/powerpc/sysdev/fsl_gtm.c
create mode 100644 include/asm-powerpc/fsl_gtm.h
diff --git a/Documentation/powerpc/booting-without-of.txt b/
Documentation/powerpc/booting-without-of.txt
index 4cc7800..827b630 100644
--- a/Documentation/powerpc/booting-without-of.txt
+++ b/Documentation/powerpc/booting-without-of.txt
[...]
+/**
+ * gtm_reset_timer16 - reset 16 bit timer with arbitrary precision
+ * @tmr: pointer to the gtm_timer structure obtained from
gtm_get_timer
+ * @usec: timer interval in microseconds
+ * @reload: if set, the timer will reset upon expiry rather than
+ * continue running free.
+ *
+ * This function (re)sets the GTM timer so that it counts up to
the requested
+ * interval value, and fires the interrupt when the value is
reached. This
+ * function will reduce the precision of the timer as needed in
order for the
+ * requested timeout to fit in a 16-bit register.
+ */
+int gtm_reset_timer16(struct gtm_timer *tmr, unsigned long usec,
bool reload)
+{
+ /* quite obvious, frequency which is enough for µSec precision */
+ int freq = 1000000;
+ unsigned int bit;
+
+ bit = fls_long(usec);
+ if (bit > 15) {
+ freq >>= bit - 15;
+ usec >>= bit - 15;
+ }
if (!freq)
return -EINVAL;
do you want me to fix this up on commit or are you going to respin the
patch set based on feedback?
- k
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