sanchayanmaity/minix
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity

ARM: fix clock

Browse source 
The GPTIMER1 clock is configured to run at 32 kHz and generate
(overflow) interrupts every 1 ms. However, the Timer Overflow Wrappping
Register (TOWR) was configured to filter every other interrupt. This
caused to the internal 'realtime' value to be off.
This commit is contained in:
Thomas Veerman 2013-01-08 13:02:38 +01:00
parent aa3623d873
commit c77228c77b
1 changed files with 12 additions and 7 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

19
kernel/arch/arm/omap_timer.c
View file

@ -23,23 +23,24 @@ int omap3_register_timer_handler(const irq_handler_t handler)
void omap3_timer_init(unsigned freq)
{
u32_t tisr;
/* Stop timer */
mmio_clear(OMAP3_GPTIMER1_TCLR, OMAP3_TCLR_ST);
/* Use 32 KHz clock source for GPTIMER1 */
mmio_clear(OMAP3_CM_CLKSEL_WKUP, OMAP3_CLKSEL_GPT1);
/* Use 1-ms tick mode for GPTIMER1 */
/* Use 1-ms tick mode for GPTIMER1 TRM 16.2.4.2.1 */
mmio_write(OMAP3_GPTIMER1_TPIR, 232000);
mmio_write(OMAP3_GPTIMER1_TNIR, -768000);
mmio_write(OMAP3_GPTIMER1_TLDR, 0xffffffe0);
mmio_write(OMAP3_GPTIMER1_TCRR, 0xffffffe0);
/* Set frequency */
mmio_write(OMAP3_GPTIMER1_TOWR, TIMER_COUNT(freq));
/* Set up overflow interrupt */
mmio_write(OMAP3_GPTIMER1_TISR, ~0);
tisr = OMAP3_TISR_MAT_IT_FLAG | OMAP3_TISR_OVF_IT_FLAG |
OMAP3_TISR_TCAR_IT_FLAG;
mmio_write(OMAP3_GPTIMER1_TISR, tisr); /* Clear interrupt status */
mmio_write(OMAP3_GPTIMER1_TIER, OMAP3_TIER_OVF_IT_ENA);
omap3_irq_unmask(OMAP3_GPT1_IRQ);
@ -55,8 +56,12 @@ void omap3_timer_stop()
void omap3_timer_int_handler()
{
/* Clear the interrupt */
mmio_write(OMAP3_GPTIMER1_TISR, ~0);
/* Clear all interrupts */
u32_t tisr;
tisr = OMAP3_TISR_MAT_IT_FLAG | OMAP3_TISR_OVF_IT_FLAG |
OMAP3_TISR_TCAR_IT_FLAG;
mmio_write(OMAP3_GPTIMER1_TISR, tisr);
tsc++;
}