Re: [PATCH-V5 3/3] ARM: OMAP: Make OMAP clocksource source selection using kernel param
Hiremath, Vaibhav hvaib...@ti.com writes: On Fri, Apr 27, 2012 at 04:08:07, Paul Walmsley wrote: On Thu, 26 Apr 2012, Paul Walmsley wrote: Okay, thanks for testing. Please do update this patch to use omap_hwmod_enable(), etc.; see for example omap_dm_timer_init_one(). And, just to be explicit, the ioremap(), clk_get(), and clk_enable() should no longer be needed for OMAP2+, once you add the omap_hwmod_enable(). What about OMAP1 architecture? Will it work? You'll need to move the ioremap/clk* usage into OMAP1 code (mach-omap1/timer32k.c), and move the omap_hwmod_enable() into OMAP2+ code (mach-omap2/timer.c). Then make the omap_init_clocksource_32k() just take the base address. If counter_32k were a real driver (and it should be) this is how things would work. For example, the GPIO driver is shared between OMAP1 and OMAP2+ and any SoC specific init is done in the SoC specific device init code instead of the driver. Hope this helps, Kevin -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH-V5 3/3] ARM: OMAP: Make OMAP clocksource source selection using kernel param
Hi
a question
On Wed, 25 Apr 2012, Vaibhav Hiremath wrote:
Current OMAP code supports couple of clocksource options based
on compilation flag (CONFIG_OMAP_32K_TIMER). The 32KHz sync-timer
and a gptimer which can run on 32KHz or system clock (e.g 38.4 MHz).
So there can be 3 options -
1. 32KHz sync-timer
2. Sys_clock based (e.g 13/19.2/26/38.4 MHz) gptimer
3. 32KHz based gptimer.
The optional gptimer based clocksource was added so that it can
give the high precision than sync-timer, so expected usage was 2
and not 3.
Unfortunately option 2, clocksource doesn't meet the requirement of
free-running clock as per clocksource need. It stops in low power states
when sys_clock is cut. That makes gptimer based clocksource option
useless for OMAP2/3/4 devices with sys_clock as a clock input.
So, in order to use option 2, deeper idle state MUST be disabled.
Option 3 will still work but it is no better than 32K sync-timer
based clocksource.
We must support both sync timer and gptimer based clocksource as
some OMAP based derivative SoCs like AM33XX does not have the
sync timer.
Considering above, make sync-timer and gptimer clocksource runtime
selectable so that both OMAP and AM continue to use the same code.
Also, in order to precisely configure/setup sched_clock for given
clocksource, decision has to be made early enough in boot sequence.
So, the solution is,
Use standard kernel parameter (clocksource=) to override
default 32k_sync-timer, in addition to this, we also use hwmod database
lookup mechanism, through which at run-time we can identify availability
of 32k-sync timer on the device, else fall back to gptimer.
...
-int __init omap_init_clocksource_32k(void)
+/**
+ * omap_init_clocksource_32k - setup and register counter 32k as a
+ * kernel clocksource
+ * @pbase: base addr of counter_32k module
+ * @size: size of counter_32k to map
+ *
+ * Returns 0 upon success or negative error code upon failure.
+ *
+ */
+int __init omap_init_clocksource_32k(u32 pbase, unsigned long size)
{
- static char err[] __initdata = KERN_ERR
- %s: can't register clocksource!\n;
-
- if (cpu_is_omap16xx() || cpu_class_is_omap2()) {
- u32 pbase;
- unsigned long size = SZ_4K;
- void __iomem *base;
- struct clk *sync_32k_ick;
-
- if (cpu_is_omap16xx()) {
- pbase = OMAP16XX_TIMER_32K_SYNCHRONIZED;
- size = SZ_1K;
- } else if (cpu_is_omap2420())
- pbase = OMAP2420_32KSYNCT_BASE + 0x10;
- else if (cpu_is_omap2430())
- pbase = OMAP2430_32KSYNCT_BASE + 0x10;
- else if (cpu_is_omap34xx())
- pbase = OMAP3430_32KSYNCT_BASE + 0x10;
- else if (cpu_is_omap44xx())
- pbase = OMAP4430_32KSYNCT_BASE + 0x10;
- else
- return -ENODEV;
-
- /* For this to work we must have a static mapping in io.c for
this area */
- base = ioremap(pbase, size);
- if (!base)
- return -ENODEV;
-
- sync_32k_ick = clk_get(NULL, omap_32ksync_ick);
- if (!IS_ERR(sync_32k_ick))
- clk_enable(sync_32k_ick);
-
- timer_32k_base = base;
-
- /*
- * 12 rough estimate from the calculations in
- * __clocksource_updatefreq_scale.
- */
- clocks_calc_mult_shift(persistent_mult, persistent_shift,
- 32768, NSEC_PER_SEC, 12);
-
- if (clocksource_mmio_init(base, 32k_counter, 32768, 250, 32,
- clocksource_mmio_readl_up))
- printk(err, 32k_counter);
-
- setup_sched_clock(omap_32k_read_sched_clock, 32, 32768);
+ int ret;
+ void __iomem *base;
+ struct clk *sync32k_ick;
+
+ if (!pbase || !size)
+ return -ENODEV;
+ /*
+ * For this to work we must have a static mapping in io.c
+ * for this area
+ */
+ base = ioremap(pbase, size);
+ if (!base) {
+ pr_err(32k_counter: failed to map base addr\n);
+ return -ENODEV;
}
- return 0;
+
+ sync32k_ick = clk_get(NULL, omap_32ksync_ick);
+ if (!IS_ERR(sync32k_ick))
+ clk_enable(sync32k_ick);
You've added hwmod data for this IP block, which is good. This will
presumably cause the IP block to be idled on boot. But you haven't
converted this code to use either the hwmod enable code -- just using
clk_get() isn't enough. (Better would be to use a driver and the PM
runtime functions, of course, but maybe this runs too early?)
If the 32k sync timer is in OCP force-idle, then that might produce the
hangs you're seeing.
- Paul
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To unsubscribe from this
RE: [PATCH-V5 3/3] ARM: OMAP: Make OMAP clocksource source selection using kernel param
On Thu, Apr 26, 2012 at 20:40:34, Paul Walmsley wrote:
Hi
a question
On Wed, 25 Apr 2012, Vaibhav Hiremath wrote:
Current OMAP code supports couple of clocksource options based
on compilation flag (CONFIG_OMAP_32K_TIMER). The 32KHz sync-timer
and a gptimer which can run on 32KHz or system clock (e.g 38.4 MHz).
So there can be 3 options -
1. 32KHz sync-timer
2. Sys_clock based (e.g 13/19.2/26/38.4 MHz) gptimer
3. 32KHz based gptimer.
The optional gptimer based clocksource was added so that it can
give the high precision than sync-timer, so expected usage was 2
and not 3.
Unfortunately option 2, clocksource doesn't meet the requirement of
free-running clock as per clocksource need. It stops in low power states
when sys_clock is cut. That makes gptimer based clocksource option
useless for OMAP2/3/4 devices with sys_clock as a clock input.
So, in order to use option 2, deeper idle state MUST be disabled.
Option 3 will still work but it is no better than 32K sync-timer
based clocksource.
We must support both sync timer and gptimer based clocksource as
some OMAP based derivative SoCs like AM33XX does not have the
sync timer.
Considering above, make sync-timer and gptimer clocksource runtime
selectable so that both OMAP and AM continue to use the same code.
Also, in order to precisely configure/setup sched_clock for given
clocksource, decision has to be made early enough in boot sequence.
So, the solution is,
Use standard kernel parameter (clocksource=) to override
default 32k_sync-timer, in addition to this, we also use hwmod database
lookup mechanism, through which at run-time we can identify availability
of 32k-sync timer on the device, else fall back to gptimer.
...
-int __init omap_init_clocksource_32k(void)
+/**
+ * omap_init_clocksource_32k - setup and register counter 32k as a
+ * kernel clocksource
+ * @pbase: base addr of counter_32k module
+ * @size: size of counter_32k to map
+ *
+ * Returns 0 upon success or negative error code upon failure.
+ *
+ */
+int __init omap_init_clocksource_32k(u32 pbase, unsigned long size)
{
- static char err[] __initdata = KERN_ERR
- %s: can't register clocksource!\n;
-
- if (cpu_is_omap16xx() || cpu_class_is_omap2()) {
- u32 pbase;
- unsigned long size = SZ_4K;
- void __iomem *base;
- struct clk *sync_32k_ick;
-
- if (cpu_is_omap16xx()) {
- pbase = OMAP16XX_TIMER_32K_SYNCHRONIZED;
- size = SZ_1K;
- } else if (cpu_is_omap2420())
- pbase = OMAP2420_32KSYNCT_BASE + 0x10;
- else if (cpu_is_omap2430())
- pbase = OMAP2430_32KSYNCT_BASE + 0x10;
- else if (cpu_is_omap34xx())
- pbase = OMAP3430_32KSYNCT_BASE + 0x10;
- else if (cpu_is_omap44xx())
- pbase = OMAP4430_32KSYNCT_BASE + 0x10;
- else
- return -ENODEV;
-
- /* For this to work we must have a static mapping in io.c for
this area */
- base = ioremap(pbase, size);
- if (!base)
- return -ENODEV;
-
- sync_32k_ick = clk_get(NULL, omap_32ksync_ick);
- if (!IS_ERR(sync_32k_ick))
- clk_enable(sync_32k_ick);
-
- timer_32k_base = base;
-
- /*
-* 12 rough estimate from the calculations in
-* __clocksource_updatefreq_scale.
-*/
- clocks_calc_mult_shift(persistent_mult, persistent_shift,
- 32768, NSEC_PER_SEC, 12);
-
- if (clocksource_mmio_init(base, 32k_counter, 32768, 250, 32,
- clocksource_mmio_readl_up))
- printk(err, 32k_counter);
-
- setup_sched_clock(omap_32k_read_sched_clock, 32, 32768);
+ int ret;
+ void __iomem *base;
+ struct clk *sync32k_ick;
+
+ if (!pbase || !size)
+ return -ENODEV;
+ /*
+* For this to work we must have a static mapping in io.c
+* for this area
+*/
+ base = ioremap(pbase, size);
+ if (!base) {
+ pr_err(32k_counter: failed to map base addr\n);
+ return -ENODEV;
}
- return 0;
+
+ sync32k_ick = clk_get(NULL, omap_32ksync_ick);
+ if (!IS_ERR(sync32k_ick))
+ clk_enable(sync32k_ick);
You've added hwmod data for this IP block, which is good. This will
presumably cause the IP block to be idled on boot. But you haven't
converted this code to use either the hwmod enable code -- just using
clk_get() isn't enough. (Better would be to use a driver and the PM
runtime functions, of course, but maybe this runs too early?)
Yes, this runs very early in the boot sequence.
If
RE: [PATCH-V5 3/3] ARM: OMAP: Make OMAP clocksource source selection using kernel param
On Thu, Apr 26, 2012 at 20:40:34, Paul Walmsley wrote: Hi a question On Wed, 25 Apr 2012, Vaibhav Hiremath wrote: snip + + sync32k_ick = clk_get(NULL, omap_32ksync_ick); + if (!IS_ERR(sync32k_ick)) + clk_enable(sync32k_ick); You've added hwmod data for this IP block, which is good. This will presumably cause the IP block to be idled on boot. But you haven't converted this code to use either the hwmod enable code -- just using clk_get() isn't enough. (Better would be to use a driver and the PM runtime functions, of course, but maybe this runs too early?) If the 32k sync timer is in OCP force-idle, then that might produce the hangs you're seeing. I tried disabling all idle related flags in hwmod entry but no change in observation, kernel still hangs. I even conformed the register content by connecting debugger, and it is set to No-idle state. Thanks, Vaibhav -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH-V5 3/3] ARM: OMAP: Make OMAP clocksource source selection using kernel param
On Thu, 26 Apr 2012, Hiremath, Vaibhav wrote: On Thu, Apr 26, 2012 at 20:40:34, Paul Walmsley wrote: On Wed, 25 Apr 2012, Vaibhav Hiremath wrote: snip + + sync32k_ick = clk_get(NULL, omap_32ksync_ick); + if (!IS_ERR(sync32k_ick)) + clk_enable(sync32k_ick); You've added hwmod data for this IP block, which is good. This will presumably cause the IP block to be idled on boot. But you haven't converted this code to use either the hwmod enable code -- just using clk_get() isn't enough. (Better would be to use a driver and the PM runtime functions, of course, but maybe this runs too early?) If the 32k sync timer is in OCP force-idle, then that might produce the hangs you're seeing. I tried disabling all idle related flags in hwmod entry but no change in observation, kernel still hangs. I even conformed the register content by connecting debugger, and it is set to No-idle state. Okay, thanks for testing. Please do update this patch to use omap_hwmod_enable(), etc.; see for example omap_dm_timer_init_one(). - Paul -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: [PATCH-V5 3/3] ARM: OMAP: Make OMAP clocksource source selection using kernel param
Vaibhav Hiremath hvaib...@ti.com writes:
Current OMAP code supports couple of clocksource options based
on compilation flag (CONFIG_OMAP_32K_TIMER). The 32KHz sync-timer
and a gptimer which can run on 32KHz or system clock (e.g 38.4 MHz).
So there can be 3 options -
1. 32KHz sync-timer
2. Sys_clock based (e.g 13/19.2/26/38.4 MHz) gptimer
3. 32KHz based gptimer.
The optional gptimer based clocksource was added so that it can
give the high precision than sync-timer, so expected usage was 2
and not 3.
Unfortunately option 2, clocksource doesn't meet the requirement of
free-running clock as per clocksource need. It stops in low power states
when sys_clock is cut. That makes gptimer based clocksource option
useless for OMAP2/3/4 devices with sys_clock as a clock input.
So, in order to use option 2, deeper idle state MUST be disabled.
Option 3 will still work but it is no better than 32K sync-timer
based clocksource.
We must support both sync timer and gptimer based clocksource as
some OMAP based derivative SoCs like AM33XX does not have the
sync timer.
Considering above, make sync-timer and gptimer clocksource runtime
selectable so that both OMAP and AM continue to use the same code.
Also, in order to precisely configure/setup sched_clock for given
clocksource, decision has to be made early enough in boot sequence.
So, the solution is,
Use standard kernel parameter (clocksource=) to override
default 32k_sync-timer, in addition to this, we also use hwmod database
lookup mechanism, through which at run-time we can identify availability
of 32k-sync timer on the device, else fall back to gptimer.
Signed-off-by: Vaibhav Hiremath hvaib...@ti.com
Signed-off-by: Felipe Balbi ba...@ti.com
Reviewed-by: Santosh Shilimkar santosh.shilim...@ti.com
Cc: Benoit Cousson b-cous...@ti.com
Cc: Tony Lindgren t...@atomide.com
Cc: Paul Walmsley p...@pwsan.com
Cc: Kevin Hilman khil...@ti.com
Cc: Tarun Kanti DebBarma tarun.ka...@ti.com
Cc: Ming Lei tom.leim...@gmail.com
---
NOTE: This patch is same as V3, without any code changes. Only
commit description has been modified.
I assume you menat v4 here, since you also change the ioremap() range in
this version compared to v3?
Also, I boot tested this on OMAP1 (5912/OSK) and OMAP3530/Overo and with
the fix for clocksource_mmio_init() below, it worked fine. I also
tested the cmdline override on OMAP3.
That being said, a few minor comments below...
arch/arm/mach-omap1/timer32k.c |6 ++-
arch/arm/mach-omap2/timer.c | 99 +--
arch/arm/plat-omap/counter_32k.c | 108
+++---
arch/arm/plat-omap/include/plat/common.h |2 +-
4 files changed, 138 insertions(+), 77 deletions(-)
diff --git a/arch/arm/mach-omap1/timer32k.c b/arch/arm/mach-omap1/timer32k.c
index 325b9a0..6262e11 100644
--- a/arch/arm/mach-omap1/timer32k.c
+++ b/arch/arm/mach-omap1/timer32k.c
@@ -71,6 +71,7 @@
/* 16xx specific defines */
#define OMAP1_32K_TIMER_BASE 0xfffb9000
+#define OMAP1_32KSYNC_TIMER_BASE 0xfffbc400
#define OMAP1_32K_TIMER_CR 0x08
#define OMAP1_32K_TIMER_TVR 0x00
#define OMAP1_32K_TIMER_TCR 0x04
@@ -184,7 +185,10 @@ static __init void omap_init_32k_timer(void)
*/
bool __init omap_32k_timer_init(void)
{
- omap_init_clocksource_32k();
+ u32 pbase;
+
+ pbase = cpu_is_omap16xx() ? OMAP1_32KSYNC_TIMER_BASE : NULL;
Compile testing on OMAP1 (using omap1_defconfig) gives a few compiler
warnings:
/work/kernel/omap/dev/arch/arm/mach-omap1/timer32k.c: In function
'omap_32k_timer_init':
/work/kernel/omap/dev/arch/arm/mach-omap1/timer32k.c:190:37: warning:
pointer/integer type mismatch in conditional expression [enabled by default]
/work/kernel/omap/dev/arch/arm/mach-omap1/timer32k.c:190:8: warning: assignment
makes integer from pointer without a cast [enabled by default]
+ omap_init_clocksource_32k(pbase, SZ_1K);
Should this be called if pbase == NULL?
If this clocksource does fail, how does the MPU clocksource get
registered?
Looking a bit closer, it appears the whole MPU vs. 32k init is even more
messed up on OMAP1 than OMAP2+ and needs some cleanup. However,
it's not directly related to this series since it was messed up before
your series.
omap_init_32k_timer();
return true;
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index ecec873..d720f58 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -243,22 +243,8 @@ static void __init omap2_gp_clockevent_init(int
gptimer_id,
}
/* Clocksource code */
-
-#ifdef CONFIG_OMAP_32K_TIMER
-/*
- * When 32k-timer is enabled, don't use GPTimer for clocksource
- * instead, just leave default clocksource which uses the 32k
- * sync counter. See clocksource setup in plat-omap/counter_32k.c
- */
-
-static void __init omap2_gp_clocksource_init(int
RE: [PATCH-V5 3/3] ARM: OMAP: Make OMAP clocksource source selection using kernel param
On Thu, 26 Apr 2012, Paul Walmsley wrote: Okay, thanks for testing. Please do update this patch to use omap_hwmod_enable(), etc.; see for example omap_dm_timer_init_one(). And, just to be explicit, the ioremap(), clk_get(), and clk_enable() should no longer be needed for OMAP2+, once you add the omap_hwmod_enable(). - Paul -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH-V5 3/3] ARM: OMAP: Make OMAP clocksource source selection using kernel param
On Fri, Apr 27, 2012 at 04:08:07, Paul Walmsley wrote: On Thu, 26 Apr 2012, Paul Walmsley wrote: Okay, thanks for testing. Please do update this patch to use omap_hwmod_enable(), etc.; see for example omap_dm_timer_init_one(). And, just to be explicit, the ioremap(), clk_get(), and clk_enable() should no longer be needed for OMAP2+, once you add the omap_hwmod_enable(). What about OMAP1 architecture? Will it work? Thanks, Vaibhav -- To unsubscribe from this list: send the line unsubscribe linux-omap in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: [PATCH-V5 3/3] ARM: OMAP: Make OMAP clocksource source selection using kernel param
On Fri, Apr 27, 2012 at 03:56:56, Hilman, Kevin wrote:
Vaibhav Hiremath hvaib...@ti.com writes:
Current OMAP code supports couple of clocksource options based
on compilation flag (CONFIG_OMAP_32K_TIMER). The 32KHz sync-timer
and a gptimer which can run on 32KHz or system clock (e.g 38.4 MHz).
So there can be 3 options -
1. 32KHz sync-timer
2. Sys_clock based (e.g 13/19.2/26/38.4 MHz) gptimer
3. 32KHz based gptimer.
The optional gptimer based clocksource was added so that it can
give the high precision than sync-timer, so expected usage was 2
and not 3.
Unfortunately option 2, clocksource doesn't meet the requirement of
free-running clock as per clocksource need. It stops in low power states
when sys_clock is cut. That makes gptimer based clocksource option
useless for OMAP2/3/4 devices with sys_clock as a clock input.
So, in order to use option 2, deeper idle state MUST be disabled.
Option 3 will still work but it is no better than 32K sync-timer
based clocksource.
We must support both sync timer and gptimer based clocksource as
some OMAP based derivative SoCs like AM33XX does not have the
sync timer.
Considering above, make sync-timer and gptimer clocksource runtime
selectable so that both OMAP and AM continue to use the same code.
Also, in order to precisely configure/setup sched_clock for given
clocksource, decision has to be made early enough in boot sequence.
So, the solution is,
Use standard kernel parameter (clocksource=) to override
default 32k_sync-timer, in addition to this, we also use hwmod database
lookup mechanism, through which at run-time we can identify availability
of 32k-sync timer on the device, else fall back to gptimer.
Signed-off-by: Vaibhav Hiremath hvaib...@ti.com
Signed-off-by: Felipe Balbi ba...@ti.com
Reviewed-by: Santosh Shilimkar santosh.shilim...@ti.com
Cc: Benoit Cousson b-cous...@ti.com
Cc: Tony Lindgren t...@atomide.com
Cc: Paul Walmsley p...@pwsan.com
Cc: Kevin Hilman khil...@ti.com
Cc: Tarun Kanti DebBarma tarun.ka...@ti.com
Cc: Ming Lei tom.leim...@gmail.com
---
NOTE: This patch is same as V3, without any code changes. Only
commit description has been modified.
I assume you menat v4 here, since you also change the ioremap() range in
this version compared to v3?
Yes, I meant V4 here.
Also, I boot tested this on OMAP1 (5912/OSK) and OMAP3530/Overo and with
the fix for clocksource_mmio_init() below, it worked fine. I also
tested the cmdline override on OMAP3.
Great, thanks for testing it on OMAP1.
That being said, a few minor comments below...
arch/arm/mach-omap1/timer32k.c |6 ++-
arch/arm/mach-omap2/timer.c | 99 +--
arch/arm/plat-omap/counter_32k.c | 108
+++---
arch/arm/plat-omap/include/plat/common.h |2 +-
4 files changed, 138 insertions(+), 77 deletions(-)
diff --git a/arch/arm/mach-omap1/timer32k.c b/arch/arm/mach-omap1/timer32k.c
index 325b9a0..6262e11 100644
--- a/arch/arm/mach-omap1/timer32k.c
+++ b/arch/arm/mach-omap1/timer32k.c
@@ -71,6 +71,7 @@
/* 16xx specific defines */
#define OMAP1_32K_TIMER_BASE 0xfffb9000
+#define OMAP1_32KSYNC_TIMER_BASE 0xfffbc400
#define OMAP1_32K_TIMER_CR 0x08
#define OMAP1_32K_TIMER_TVR0x00
#define OMAP1_32K_TIMER_TCR0x04
@@ -184,7 +185,10 @@ static __init void omap_init_32k_timer(void)
*/
bool __init omap_32k_timer_init(void)
{
- omap_init_clocksource_32k();
+ u32 pbase;
+
+ pbase = cpu_is_omap16xx() ? OMAP1_32KSYNC_TIMER_BASE : NULL;
Compile testing on OMAP1 (using omap1_defconfig) gives a few compiler
warnings:
/work/kernel/omap/dev/arch/arm/mach-omap1/timer32k.c: In function
'omap_32k_timer_init':
/work/kernel/omap/dev/arch/arm/mach-omap1/timer32k.c:190:37: warning:
pointer/integer type mismatch in conditional expression [enabled by default]
/work/kernel/omap/dev/arch/arm/mach-omap1/timer32k.c:190:8: warning:
assignment makes integer from pointer without a cast [enabled by default]
Oops. I only tested with omap2plus_defconfig, I should have also checked
omap1_defconfig. I will fix this in next version.
+ omap_init_clocksource_32k(pbase, SZ_1K);
Should this be called if pbase == NULL?
The first thing in the function we do is to check for pbase != NULL, and
returns error; so I did not put check again here.
If this clocksource does fail, how does the MPU clocksource get
registered?
I believe, the original code itself was written with the assumption that,
there will not be any failures from omap_32k_timer_init(), I did not modify
it, since I can not test it here at my end. Don't have omap1 board with me.
If you help me in validating it, I will create a patch for this cleanup.
Looking a bit closer, it appears the whole MPU vs. 32k init is even more
[PATCH-V5 3/3] ARM: OMAP: Make OMAP clocksource source selection using kernel param
Current OMAP code supports couple of clocksource options based
on compilation flag (CONFIG_OMAP_32K_TIMER). The 32KHz sync-timer
and a gptimer which can run on 32KHz or system clock (e.g 38.4 MHz).
So there can be 3 options -
1. 32KHz sync-timer
2. Sys_clock based (e.g 13/19.2/26/38.4 MHz) gptimer
3. 32KHz based gptimer.
The optional gptimer based clocksource was added so that it can
give the high precision than sync-timer, so expected usage was 2
and not 3.
Unfortunately option 2, clocksource doesn't meet the requirement of
free-running clock as per clocksource need. It stops in low power states
when sys_clock is cut. That makes gptimer based clocksource option
useless for OMAP2/3/4 devices with sys_clock as a clock input.
So, in order to use option 2, deeper idle state MUST be disabled.
Option 3 will still work but it is no better than 32K sync-timer
based clocksource.
We must support both sync timer and gptimer based clocksource as
some OMAP based derivative SoCs like AM33XX does not have the
sync timer.
Considering above, make sync-timer and gptimer clocksource runtime
selectable so that both OMAP and AM continue to use the same code.
Also, in order to precisely configure/setup sched_clock for given
clocksource, decision has to be made early enough in boot sequence.
So, the solution is,
Use standard kernel parameter (clocksource=) to override
default 32k_sync-timer, in addition to this, we also use hwmod database
lookup mechanism, through which at run-time we can identify availability
of 32k-sync timer on the device, else fall back to gptimer.
Signed-off-by: Vaibhav Hiremath hvaib...@ti.com
Signed-off-by: Felipe Balbi ba...@ti.com
Reviewed-by: Santosh Shilimkar santosh.shilim...@ti.com
Cc: Benoit Cousson b-cous...@ti.com
Cc: Tony Lindgren t...@atomide.com
Cc: Paul Walmsley p...@pwsan.com
Cc: Kevin Hilman khil...@ti.com
Cc: Tarun Kanti DebBarma tarun.ka...@ti.com
Cc: Ming Lei tom.leim...@gmail.com
---
NOTE: This patch is same as V3, without any code changes. Only
commit description has been modified.
arch/arm/mach-omap1/timer32k.c |6 ++-
arch/arm/mach-omap2/timer.c | 99 +--
arch/arm/plat-omap/counter_32k.c | 108 +++---
arch/arm/plat-omap/include/plat/common.h |2 +-
4 files changed, 138 insertions(+), 77 deletions(-)
diff --git a/arch/arm/mach-omap1/timer32k.c b/arch/arm/mach-omap1/timer32k.c
index 325b9a0..6262e11 100644
--- a/arch/arm/mach-omap1/timer32k.c
+++ b/arch/arm/mach-omap1/timer32k.c
@@ -71,6 +71,7 @@
/* 16xx specific defines */
#define OMAP1_32K_TIMER_BASE 0xfffb9000
+#define OMAP1_32KSYNC_TIMER_BASE 0xfffbc400
#define OMAP1_32K_TIMER_CR 0x08
#define OMAP1_32K_TIMER_TVR0x00
#define OMAP1_32K_TIMER_TCR0x04
@@ -184,7 +185,10 @@ static __init void omap_init_32k_timer(void)
*/
bool __init omap_32k_timer_init(void)
{
- omap_init_clocksource_32k();
+ u32 pbase;
+
+ pbase = cpu_is_omap16xx() ? OMAP1_32KSYNC_TIMER_BASE : NULL;
+ omap_init_clocksource_32k(pbase, SZ_1K);
omap_init_32k_timer();
return true;
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index ecec873..d720f58 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -243,22 +243,8 @@ static void __init omap2_gp_clockevent_init(int gptimer_id,
}
/* Clocksource code */
-
-#ifdef CONFIG_OMAP_32K_TIMER
-/*
- * When 32k-timer is enabled, don't use GPTimer for clocksource
- * instead, just leave default clocksource which uses the 32k
- * sync counter. See clocksource setup in plat-omap/counter_32k.c
- */
-
-static void __init omap2_gp_clocksource_init(int unused, const char *dummy)
-{
- omap_init_clocksource_32k();
-}
-
-#else
-
static struct omap_dm_timer clksrc;
+static bool use_gptimer_clksrc;
/*
* clocksource
@@ -285,7 +271,33 @@ static u32 notrace dmtimer_read_sched_clock(void)
}
/* Setup free-running counter for clocksource */
-static void __init omap2_gp_clocksource_init(int gptimer_id,
+static int __init omap2_sync32k_clocksource_init(void)
+{
+ int ret;
+ struct omap_hwmod *oh;
+ struct resource res;
+ const char *oh_name = counter_32k;
+
+ oh = omap_hwmod_lookup(oh_name);
+ if (!oh || oh-slaves_cnt == 0)
+ return -ENODEV;
+
+ ret = omap_hwmod_get_resource_byname(oh, IORESOURCE_MEM, NULL, res);
+ if (ret) {
+ pr_warn(%s: failed to get counter_32k resource (%d)\n,
+ __func__, ret);
+ return ret;
+ }
+
+ ret = omap_init_clocksource_32k(res.start, resource_size(res));
+ if (ret)
+ pr_warn(%s: failed to initialize counter_32k (%d)\n,
+ __func__, ret);
+
+ return ret;
+}
+
+static void __init omap2_gptimer_clocksource_init(int
