Nishant, > -----Original Message----- > From: Nishanth Menon [mailto:menon.nishanth@xxxxxxxxx] > Sent: Monday, June 21, 2010 4:15 PM > To: DebBarma, Tarun Kanti > Cc: linux-omap@xxxxxxxxxxxxxxx; R, Sricharan > Subject: Re: [PATCH v2] OMAP:GPTIMER:1ms tick generation correction > > NAK - my prev comments are not fixed here either. > > On 06/21/2010 03:23 PM, Tarun Kanti DebBarma wrote: > > Generation of 1ms granular GPTIMER events using 32KHz or system > > clocks as inputs does not have whole number count value to load > > into the register. This inaccurate count value with respect to 1ms > > period leads to time drift subsequently. OMAP3 and later silicons > > have dedicated registers for GPTIMER1, GPTIMER2 and GPTIMER10, > > which can be programmed with computed values to keep this error > > controlled within specified limit. > > > > Version 2: > move this to diffstat section please. > > (i) optimized omap_dm_timer_ms_correction() function and corrected > > error in computing the positive and negative increments. > > (ii) typo corrections in comment section and warning removal related > > to 80-character limit > > > > Tested on Zoom3 using Linus tree. > > > > Signed-off-by: R Sricharan<r.sricharan@xxxxxx> > > Signed-off-by: Tarun Kanti DebBarma<tarun.kanti@xxxxxx> > > --- > > arch/arm/plat-omap/dmtimer.c | 131 > +++++++++++++++++++++-------- > > arch/arm/plat-omap/include/plat/dmtimer.h | 1 + > > 2 files changed, 96 insertions(+), 36 deletions(-) > > > > diff --git a/arch/arm/plat-omap/dmtimer.c b/arch/arm/plat-omap/dmtimer.c > > index c64875f..42344a7 > > --- a/arch/arm/plat-omap/dmtimer.c > > +++ b/arch/arm/plat-omap/dmtimer.c > > @@ -160,6 +160,9 @@ struct omap_dm_timer { > > unsigned reserved:1; > > unsigned enabled:1; > > unsigned posted:1; > > +#ifdef CONFIG_ARCH_OMAP2PLUS > > + unsigned ms_correction:1; > > +#endif > > }; > > > > static int dm_timer_count; > > @@ -185,18 +188,30 @@ static const int omap1_dm_timer_count = > ARRAY_SIZE(omap1_dm_timers); > > > > #ifdef CONFIG_ARCH_OMAP2 > > static struct omap_dm_timer omap2_dm_timers[] = { > > - { .phys_base = 0x48028000, .irq = INT_24XX_GPTIMER1 }, > > - { .phys_base = 0x4802a000, .irq = INT_24XX_GPTIMER2 }, > > - { .phys_base = 0x48078000, .irq = INT_24XX_GPTIMER3 }, > > - { .phys_base = 0x4807a000, .irq = INT_24XX_GPTIMER4 }, > > - { .phys_base = 0x4807c000, .irq = INT_24XX_GPTIMER5 }, > > - { .phys_base = 0x4807e000, .irq = INT_24XX_GPTIMER6 }, > > - { .phys_base = 0x48080000, .irq = INT_24XX_GPTIMER7 }, > > - { .phys_base = 0x48082000, .irq = INT_24XX_GPTIMER8 }, > > - { .phys_base = 0x48084000, .irq = INT_24XX_GPTIMER9 }, > > - { .phys_base = 0x48086000, .irq = INT_24XX_GPTIMER10 }, > > - { .phys_base = 0x48088000, .irq = INT_24XX_GPTIMER11 }, > > - { .phys_base = 0x4808a000, .irq = INT_24XX_GPTIMER12 }, > > + { .phys_base = 0x48028000, .irq = INT_24XX_GPTIMER1, > > + .ms_correction = 0 }, > > + { .phys_base = 0x4802a000, .irq = INT_24XX_GPTIMER2, > > + .ms_correction = 0 }, > > + { .phys_base = 0x48078000, .irq = INT_24XX_GPTIMER3, > > + .ms_correction = 0 }, > > + { .phys_base = 0x4807a000, .irq = INT_24XX_GPTIMER4, > > + .ms_correction = 0 }, > > + { .phys_base = 0x4807c000, .irq = INT_24XX_GPTIMER5, > > + .ms_correction = 0 }, > > + { .phys_base = 0x4807e000, .irq = INT_24XX_GPTIMER6, > > + .ms_correction = 0 }, > > + { .phys_base = 0x48080000, .irq = INT_24XX_GPTIMER7, > > + .ms_correction = 0 }, > > + { .phys_base = 0x48082000, .irq = INT_24XX_GPTIMER8, > > + .ms_correction = 0 }, > > + { .phys_base = 0x48084000, .irq = INT_24XX_GPTIMER9, > > + .ms_correction = 0 }, > > + { .phys_base = 0x48086000, .irq = INT_24XX_GPTIMER10, > > + .ms_correction = 0 }, > > + { .phys_base = 0x48088000, .irq = INT_24XX_GPTIMER11, > > + .ms_correction = 0 }, > > + { .phys_base = 0x4808a000, .irq = INT_24XX_GPTIMER12, > > + .ms_correction = 0 }, > > ignore of previous comments on .ms_correction initialization. > try the output of the following code: > struct b { > unsigned char z:1; > unsigned char a:1; > }; > > static struct b b1[2]={ > {.z =1}, > {.a = 1}, > }; > > unsigned int main() > { > int i; > for (i=0; i<2; i++) > printf("%d: %d %d\n", i, b1[i].z, b1[i].a); > } This comment is not clear to me. Are you suggesting to make the initialization of ms_correction variable in a separate function instead of doing the present way? > > > }; > > > > static const char *omap2_dm_source_names[] __initdata = { > > @@ -218,18 +233,30 @@ static const int omap2_dm_timer_count = > ARRAY_SIZE(omap2_dm_timers); > > > > #ifdef CONFIG_ARCH_OMAP3 > > static struct omap_dm_timer omap3_dm_timers[] = { > > - { .phys_base = 0x48318000, .irq = INT_24XX_GPTIMER1 }, > > - { .phys_base = 0x49032000, .irq = INT_24XX_GPTIMER2 }, > > - { .phys_base = 0x49034000, .irq = INT_24XX_GPTIMER3 }, > > - { .phys_base = 0x49036000, .irq = INT_24XX_GPTIMER4 }, > > - { .phys_base = 0x49038000, .irq = INT_24XX_GPTIMER5 }, > > - { .phys_base = 0x4903A000, .irq = INT_24XX_GPTIMER6 }, > > - { .phys_base = 0x4903C000, .irq = INT_24XX_GPTIMER7 }, > > - { .phys_base = 0x4903E000, .irq = INT_24XX_GPTIMER8 }, > > - { .phys_base = 0x49040000, .irq = INT_24XX_GPTIMER9 }, > > - { .phys_base = 0x48086000, .irq = INT_24XX_GPTIMER10 }, > > - { .phys_base = 0x48088000, .irq = INT_24XX_GPTIMER11 }, > > - { .phys_base = 0x48304000, .irq = INT_34XX_GPT12_IRQ }, > > + { .phys_base = 0x48318000, .irq = INT_24XX_GPTIMER1, > > + .ms_correction = 1 }, > > + { .phys_base = 0x49032000, .irq = INT_24XX_GPTIMER2, > > + .ms_correction = 1 }, > > + { .phys_base = 0x49034000, .irq = INT_24XX_GPTIMER3, > > + .ms_correction = 0 }, > > + { .phys_base = 0x49036000, .irq = INT_24XX_GPTIMER4, > > + .ms_correction = 0 }, > > + { .phys_base = 0x49038000, .irq = INT_24XX_GPTIMER5, > > + .ms_correction = 0 }, > > + { .phys_base = 0x4903A000, .irq = INT_24XX_GPTIMER6, > > + .ms_correction = 0 }, > > + { .phys_base = 0x4903C000, .irq = INT_24XX_GPTIMER7, > > + .ms_correction = 0 }, > > + { .phys_base = 0x4903E001, .irq = INT_24XX_GPTIMER8, > > + .ms_correction = 0 }, > > + { .phys_base = 0x49040000, .irq = INT_24XX_GPTIMER9, > > + .ms_correction = 0 }, > > + { .phys_base = 0x48086000, .irq = INT_24XX_GPTIMER10, > > + .ms_correction = 1 }, > > + { .phys_base = 0x48088000, .irq = INT_24XX_GPTIMER11, > > + .ms_correction = 0 }, > > + { .phys_base = 0x48304000, .irq = INT_34XX_GPT12_IRQ, > > + > > NAK Will be taken care. > .ms_correction = 0 }, > > }; > > > > static const char *omap3_dm_source_names[] __initdata = { > > @@ -250,18 +277,30 @@ static const int omap3_dm_timer_count = > ARRAY_SIZE(omap3_dm_timers); > > > > #ifdef CONFIG_ARCH_OMAP4 > > static struct omap_dm_timer omap4_dm_timers[] = { > > - { .phys_base = 0x4a318000, .irq = OMAP44XX_IRQ_GPT1 }, > > - { .phys_base = 0x48032000, .irq = OMAP44XX_IRQ_GPT2 }, > > - { .phys_base = 0x48034000, .irq = OMAP44XX_IRQ_GPT3 }, > > - { .phys_base = 0x48036000, .irq = OMAP44XX_IRQ_GPT4 }, > > - { .phys_base = 0x40138000, .irq = OMAP44XX_IRQ_GPT5 }, > > - { .phys_base = 0x4013a000, .irq = OMAP44XX_IRQ_GPT6 }, > > - { .phys_base = 0x4013a000, .irq = OMAP44XX_IRQ_GPT7 }, > > - { .phys_base = 0x4013e000, .irq = OMAP44XX_IRQ_GPT8 }, > > - { .phys_base = 0x4803e000, .irq = OMAP44XX_IRQ_GPT9 }, > > - { .phys_base = 0x48086000, .irq = OMAP44XX_IRQ_GPT10 }, > > - { .phys_base = 0x48088000, .irq = OMAP44XX_IRQ_GPT11 }, > > - { .phys_base = 0x4a320000, .irq = OMAP44XX_IRQ_GPT12 }, > > + { .phys_base = 0x4a318000, .irq = OMAP44XX_IRQ_GPT1, > > + .ms_correction = 1 }, > > + { .phys_base = 0x48032000, .irq = OMAP44XX_IRQ_GPT2, > > + .ms_correction = 1 }, > > + { .phys_base = 0x48034000, .irq = OMAP44XX_IRQ_GPT3, > > + .ms_correction = 0 }, > > + { .phys_base = 0x48036000, .irq = OMAP44XX_IRQ_GPT4, > > + .ms_correction = 0 }, > > + { .phys_base = 0x40138000, .irq = OMAP44XX_IRQ_GPT5, > > + .ms_correction = 0 }, > > + { .phys_base = 0x4013a000, .irq = OMAP44XX_IRQ_GPT6, > > + .ms_correction = 0 }, > > + { .phys_base = 0x4013a000, .irq = OMAP44XX_IRQ_GPT7, > > + .ms_correction = 0 }, > > + { .phys_base = 0x4013e000, .irq = OMAP44XX_IRQ_GPT8, > > + .ms_correction = 0 }, > > + { .phys_base = 0x4803e000, .irq = OMAP44XX_IRQ_GPT9, > > + .ms_correction = 0 }, > > + { .phys_base = 0x48086000, .irq = OMAP44XX_IRQ_GPT10, > > + .ms_correction = 1 }, > > + { .phys_base = 0x48088000, .irq = OMAP44XX_IRQ_GPT11, > > + .ms_correction = 0 }, > > + { .phys_base = 0x4a320000, .irq = OMAP44XX_IRQ_GPT12, > > + > .ms_correction = 0 }, > NAK Will be taken care. > > > }; > > static const char *omap4_dm_source_names[] __initdata = { > > "sys_clkin_ck", > > @@ -612,6 +651,10 @@ void omap_dm_timer_set_load_start(struct > omap_dm_timer *timer, int autoreload, > > { > > u32 l; > > > > +#ifdef CONFIG_ARCH_OMAP2PLUS > > + if (timer->ms_correction) > > + omap_dm_timer_ms_correction(timer, load); > > +#endif > > l = omap_dm_timer_read_reg(timer, OMAP_TIMER_CTRL_REG); > > if (autoreload) { > > l |= OMAP_TIMER_CTRL_AR; > > @@ -733,6 +776,22 @@ int omap_dm_timers_active(void) > > } > > EXPORT_SYMBOL_GPL(omap_dm_timers_active); > > > > +/** > > + * omap_dm_timer_ms_correction - hardware correction for millisecond > timer > > + * @timer: GPTIMER on which the correction support is to be applied > > + * @load: timer load value, used here to extract the expiry count > > + */ > > +void omap_dm_timer_ms_correction(struct omap_dm_timer *timer, u32 load) > does this function need to be exposed to the world? why? > omap_dm_timer_set_load_start seems to automatically use it. and > omap_dm_timer_set_load_start is private within dmtimer.c This will be changed to static void omap_dm_timer_ms_correction (...) > > > +{ > > + int pos_increment, neg_increment; > > + unsigned int count = (0xFFFFFFFF - load)*1024; > > + > > + pos_increment = (((count/1000)+1)*1000000) - (count*1000); > > + neg_increment = ((count/1000)*1000000) - (count*1000); > > NAK. comments from last time not fixed! - fix check patch AND use > kernel.h ROUND functions. I did not quite understand the comment. With regard to using round() macro in kernel.h is there any advantage? > > > + omap_dm_timer_write_reg(timer, OMAP_TIMER_TICK_POS_REG, > pos_increment); > > + omap_dm_timer_write_reg(timer, OMAP_TIMER_TICK_NEG_REG, > neg_increment); > > +} > > + > > int __init omap_dm_timer_init(void) > > { > > struct omap_dm_timer *timer; > > diff --git a/arch/arm/plat-omap/include/plat/dmtimer.h b/arch/arm/plat- > omap/include/plat/dmtimer.h > > index 20f1054..ad37bcc 100644 > > --- a/arch/arm/plat-omap/include/plat/dmtimer.h > > +++ b/arch/arm/plat-omap/include/plat/dmtimer.h > > @@ -80,5 +80,6 @@ void omap_dm_timer_write_counter(struct omap_dm_timer > *timer, unsigned int value > > > > int omap_dm_timers_active(void); > > > > +void omap_dm_timer_ms_correction(struct omap_dm_timer *timer, u32 > load); > as mentioned offline: why does this function need to be exposed to the > world? This will be removed. > > > > > #endif /* __ASM_ARCH_DMTIMER_H */ > > > Regards, > Nishanth Menon -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
