+++ /dev/null
-#include <linux/init.h>
-#include <linux/pci.h>
-#include <linux/percpu.h>
-#include <linux/delay.h>
-#include <linux/spinlock.h>
-#include <linux/interrupt.h>
-
-#include <asm/hpet.h>
-#include <asm/time.h>
-
-#define SMBUS_CFG_BASE (loongson_sysconf.ht_control_base + 0x0300a000)
-#define SMBUS_PCI_REG40 0x40
-#define SMBUS_PCI_REG64 0x64
-#define SMBUS_PCI_REGB4 0xb4
-
-static DEFINE_SPINLOCK(hpet_lock);
-DEFINE_PER_CPU(struct clock_event_device, hpet_clockevent_device);
-
-static unsigned int smbus_read(int offset)
-{
- return *(volatile unsigned int *)(SMBUS_CFG_BASE + offset);
-}
-
-static void smbus_write(int offset, int data)
-{
- *(volatile unsigned int *)(SMBUS_CFG_BASE + offset) = data;
-}
-
-static void smbus_enable(int offset, int bit)
-{
- unsigned int cfg = smbus_read(offset);
-
- cfg |= bit;
- smbus_write(offset, cfg);
-}
-
-static int hpet_read(int offset)
-{
- return *(volatile unsigned int *)(HPET_MMIO_ADDR + offset);
-}
-
-static void hpet_write(int offset, int data)
-{
- *(volatile unsigned int *)(HPET_MMIO_ADDR + offset) = data;
-}
-
-static void hpet_start_counter(void)
-{
- unsigned int cfg = hpet_read(HPET_CFG);
-
- cfg |= HPET_CFG_ENABLE;
- hpet_write(HPET_CFG, cfg);
-}
-
-static void hpet_stop_counter(void)
-{
- unsigned int cfg = hpet_read(HPET_CFG);
-
- cfg &= ~HPET_CFG_ENABLE;
- hpet_write(HPET_CFG, cfg);
-}
-
-static void hpet_reset_counter(void)
-{
- hpet_write(HPET_COUNTER, 0);
- hpet_write(HPET_COUNTER + 4, 0);
-}
-
-static void hpet_restart_counter(void)
-{
- hpet_stop_counter();
- hpet_reset_counter();
- hpet_start_counter();
-}
-
-static void hpet_enable_legacy_int(void)
-{
- /* Do nothing on Loongson-3 */
-}
-
-static void hpet_set_mode(enum clock_event_mode mode,
- struct clock_event_device *evt)
-{
- int cfg = 0;
-
- spin_lock(&hpet_lock);
- switch (mode) {
- case CLOCK_EVT_MODE_PERIODIC:
- pr_info("set clock event to periodic mode!\n");
- /* stop counter */
- hpet_stop_counter();
-
- /* enables the timer0 to generate a periodic interrupt */
- cfg = hpet_read(HPET_T0_CFG);
- cfg &= ~HPET_TN_LEVEL;
- cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
- HPET_TN_SETVAL | HPET_TN_32BIT;
- hpet_write(HPET_T0_CFG, cfg);
-
- /* set the comparator */
- hpet_write(HPET_T0_CMP, HPET_COMPARE_VAL);
- udelay(1);
- hpet_write(HPET_T0_CMP, HPET_COMPARE_VAL);
-
- /* start counter */
- hpet_start_counter();
- break;
- case CLOCK_EVT_MODE_SHUTDOWN:
- case CLOCK_EVT_MODE_UNUSED:
- cfg = hpet_read(HPET_T0_CFG);
- cfg &= ~HPET_TN_ENABLE;
- hpet_write(HPET_T0_CFG, cfg);
- break;
- case CLOCK_EVT_MODE_ONESHOT:
- pr_info("set clock event to one shot mode!\n");
- cfg = hpet_read(HPET_T0_CFG);
- /* set timer0 type
- * 1 : periodic interrupt
- * 0 : non-periodic(oneshot) interrupt
- */
- cfg &= ~HPET_TN_PERIODIC;
- cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
- hpet_write(HPET_T0_CFG, cfg);
- break;
- case CLOCK_EVT_MODE_RESUME:
- hpet_enable_legacy_int();
- break;
- }
- spin_unlock(&hpet_lock);
-}
-
-static int hpet_next_event(unsigned long delta,
- struct clock_event_device *evt)
-{
- unsigned int cnt;
- int res;
-
- cnt = hpet_read(HPET_COUNTER);
- cnt += delta;
- hpet_write(HPET_T0_CMP, cnt);
-
- res = ((int)(hpet_read(HPET_COUNTER) - cnt) > 0) ? -ETIME : 0;
- return res;
-}
-
-static irqreturn_t hpet_irq_handler(int irq, void *data)
-{
- int is_irq;
- struct clock_event_device *cd;
- unsigned int cpu = smp_processor_id();
-
- is_irq = hpet_read(HPET_STATUS);
- if (is_irq & HPET_T0_IRS) {
- /* clear the TIMER0 irq status register */
- hpet_write(HPET_STATUS, HPET_T0_IRS);
- cd = &per_cpu(hpet_clockevent_device, cpu);
- cd->event_handler(cd);
- return IRQ_HANDLED;
- }
- return IRQ_NONE;
-}
-
-static struct irqaction hpet_irq = {
- .handler = hpet_irq_handler,
- .flags = IRQF_NOBALANCING | IRQF_TIMER,
- .name = "hpet",
-};
-
-/*
- * hpet address assignation and irq setting should be done in bios.
- * but pmon don't do this, we just setup here directly.
- * The operation under is normal. unfortunately, hpet_setup process
- * is before pci initialize.
- *
- * {
- * struct pci_dev *pdev;
- *
- * pdev = pci_get_device(PCI_VENDOR_ID_ATI, PCI_DEVICE_ID_ATI_SBX00_SMBUS, NULL);
- * pci_write_config_word(pdev, SMBUS_PCI_REGB4, HPET_ADDR);
- *
- * ...
- * }
- */
-static void hpet_setup(void)
-{
- /* set hpet base address */
- smbus_write(SMBUS_PCI_REGB4, HPET_ADDR);
-
- /* enable decodeing of access to HPET MMIO*/
- smbus_enable(SMBUS_PCI_REG40, (1 << 28));
-
- /* HPET irq enable */
- smbus_enable(SMBUS_PCI_REG64, (1 << 10));
-
- hpet_enable_legacy_int();
-}
-
-void __init setup_hpet_timer(void)
-{
- unsigned int cpu = smp_processor_id();
- struct clock_event_device *cd;
-
- hpet_setup();
-
- cd = &per_cpu(hpet_clockevent_device, cpu);
- cd->name = "hpet";
- cd->rating = 320;
- cd->features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT;
- cd->set_mode = hpet_set_mode;
- cd->set_next_event = hpet_next_event;
- cd->irq = HPET_T0_IRQ;
- cd->cpumask = cpumask_of(cpu);
- clockevent_set_clock(cd, HPET_FREQ);
- cd->max_delta_ns = clockevent_delta2ns(0x7fffffff, cd);
- cd->min_delta_ns = 5000;
-
- clockevents_register_device(cd);
- setup_irq(HPET_T0_IRQ, &hpet_irq);
- pr_info("hpet clock event device register\n");
-}
-
-static cycle_t hpet_read_counter(struct clocksource *cs)
-{
- return (cycle_t)hpet_read(HPET_COUNTER);
-}
-
-static void hpet_suspend(struct clocksource *cs)
-{
-}
-
-static void hpet_resume(struct clocksource *cs)
-{
- hpet_setup();
- hpet_restart_counter();
-}
-
-static struct clocksource csrc_hpet = {
- .name = "hpet",
- /* mips clocksource rating is less than 300, so hpet is better. */
- .rating = 300,
- .read = hpet_read_counter,
- .mask = CLOCKSOURCE_MASK(32),
- /* oneshot mode work normal with this flag */
- .flags = CLOCK_SOURCE_IS_CONTINUOUS,
- .suspend = hpet_suspend,
- .resume = hpet_resume,
- .mult = 0,
- .shift = 10,
-};
-
-int __init init_hpet_clocksource(void)
-{
- csrc_hpet.mult = clocksource_hz2mult(HPET_FREQ, csrc_hpet.shift);
- return clocksource_register_hz(&csrc_hpet, HPET_FREQ);
-}
-
-arch_initcall(init_hpet_clocksource);
Code Review / kvmfornfv.git / blobdiff