Implement SC520 timers
Signed-off-by: Graeme Russ <graeme.russ at gmail.com>
diff --git a/cpu/i386/sc520/sc520_timer.c b/cpu/i386/sc520/sc520_timer.c
index 7578511..2cb8656 100644
--- a/cpu/i386/sc520/sc520_timer.c
+++ b/cpu/i386/sc520/sc520_timer.c
@@ -27,47 +27,56 @@
#include <asm/interrupt.h>
#include <asm/ic/sc520.h>
-void reset_timer(void)
+void sc520_timer_isr(void)
{
- write_mmcr_word(SC520_GPTMR0CNT, 0);
- write_mmcr_word(SC520_GPTMR0CTL, 0x6001);
-
+ /* Ack the GP Timer Interrupt */
+ write_mmcr_byte (SC520_GPTMRSTA, 0x02);
}
-ulong get_timer(ulong base)
+int timer_init(void)
{
- /* fixme: 30 or 33 */
- return read_mmcr_word(SC520_GPTMR0CNT) / 33;
-}
+ /* Map GP Timer 1 to Master PIC IR0 */
+ write_mmcr_byte (SC520_GPTMR1MAP, 0x01);
-void set_timer(ulong t)
-{
- /* FixMe: use two cascade coupled timers */
- write_mmcr_word(SC520_GPTMR0CTL, 0x4001);
- write_mmcr_word(SC520_GPTMR0CNT, t*33);
- write_mmcr_word(SC520_GPTMR0CTL, 0x6001);
-}
+ /* Disable GP Timers 1 & 2 - Allow configuration writes */
+ write_mmcr_word (SC520_GPTMR1CTL, 0x4000);
+ write_mmcr_word (SC520_GPTMR2CTL, 0x4000);
+ /* Reset GP Timers 1 & 2 */
+ write_mmcr_word (SC520_GPTMR1CNT, 0x0000);
+ write_mmcr_word (SC520_GPTMR2CNT, 0x0000);
+
+ /* Setup GP Timer 2 as a 100kHz (10us) prescaler */
+ write_mmcr_word (SC520_GPTMR2MAXCMPA, 83);
+ write_mmcr_word (SC520_GPTMR2CTL, 0xc001);
+
+ /* Setup GP Timer 1 as a 1000 Hz (1ms) interrupt generator */
+ write_mmcr_word (SC520_GPTMR1MAXCMPA, 100);
+ write_mmcr_word (SC520_GPTMR1CTL, 0xe009);
+
+ /* Clear the GP Timers status register */
+ write_mmcr_byte (SC520_GPTMRSTA, 0x07);
+
+ /* Register the SC520 specific timer interrupt handler */
+ register_timer_isr (sc520_timer_isr);
+
+ /* Install interrupt handler for GP Timer 1 */
+ irq_install_handler (0, timer_isr, NULL);
+ unmask_irq (0);
+
+ return 0;
+}
void udelay(unsigned long usec)
{
- int m=0;
+ int m = 0;
long u;
- read_mmcr_word(SC520_SWTMRMILLI);
- read_mmcr_word(SC520_SWTMRMICRO);
-
-#if 0
- /* do not enable this line, udelay is used in the serial driver -> recursion */
- printf("udelay: %ld m.u %d.%d tm.tu %d.%d\n", usec, m, u, tm, tu);
-#endif
- while (1) {
-
- m += read_mmcr_word(SC520_SWTMRMILLI);
- u = read_mmcr_word(SC520_SWTMRMICRO) + (m * 1000);
+ read_mmcr_word (SC520_SWTMRMILLI);
+ read_mmcr_word (SC520_SWTMRMICRO);
- if (usec <= u) {
- break;
- }
- }
+ do {
+ m += read_mmcr_word (SC520_SWTMRMILLI);
+ u = read_mmcr_word (SC520_SWTMRMICRO) + (m * 1000);
+ } while (u < usec);
}