static int sh_cmt_enable(struct sh_cmt_priv *p, unsigned long *rate)
{
int k, ret;
/* enable clock */
ret = clk_enable(p->clk);
if (ret) {
dev_err(&p->pdev->dev, "cannot enable clock\n");
goto err0;
}
/* make sure channel is disabled */
sh_cmt_start_stop_ch(p, 0);
/* configure channel, periodic mode and maximum timeout */
if (p->width == 16) {
*rate = clk_get_rate(p->clk) / 512;
sh_cmt_write(p, CMCSR, 0x43);
} else {
*rate = clk_get_rate(p->clk) / 8;
sh_cmt_write(p, CMCSR, 0x01a4);
}
sh_cmt_write(p, CMCOR, 0xffffffff);
sh_cmt_write(p, CMCNT, 0);
/*
* According to the sh73a0 user's manual, as CMCNT can be operated
* only by the RCLK (Pseudo 32 KHz), there's one restriction on
* modifying CMCNT register; two RCLK cycles are necessary before
* this register is either read or any modification of the value
* it holds is reflected in the LSI's actual operation.
*
* While at it, we're supposed to clear out the CMCNT as of this
* moment, so make sure it's processed properly here. This will
* take RCLKx2 at maximum.
*/
for (k = 0; k < 100; k++) {
if (!sh_cmt_read(p, CMCNT))
break;
udelay(1);
}
if (sh_cmt_read(p, CMCNT)) {
dev_err(&p->pdev->dev, "cannot clear CMCNT\n");
ret = -ETIMEDOUT;
goto err1;
}
/* enable channel */
sh_cmt_start_stop_ch(p, 1);
return 0;
err1:
/* stop clock */
clk_disable(p->clk);
err0:
return ret;
}
static unsigned long sh_cmt_get_counter(struct sh_cmt_priv *p,
int *has_wrapped)
{
unsigned long v1, v2, v3;
/* Make sure the timer value is stable. Stolen from acpi_pm.c */
do {
v1 = sh_cmt_read(p, CMCNT);
v2 = sh_cmt_read(p, CMCNT);
v3 = sh_cmt_read(p, CMCNT);
} while (unlikely((v1 > v2 && v1 < v3) || (v2 > v3 && v2 < v1)
|| (v3 > v1 && v3 < v2)));
*has_wrapped = sh_cmt_read(p, CMCSR) & p->overflow_bit;
return v2;
}
static unsigned long sh_cmt_get_counter(struct sh_cmt_priv *p,
int *has_wrapped)
{
unsigned long v1, v2, v3;
int o1, o2;
o1 = sh_cmt_read(p, CMCSR) & p->overflow_bit;
do {
o2 = o1;
v1 = sh_cmt_read(p, CMCNT);
v2 = sh_cmt_read(p, CMCNT);
v3 = sh_cmt_read(p, CMCNT);
o1 = sh_cmt_read(p, CMCSR) & p->overflow_bit;
} while (unlikely((o1 != o2) || (v1 > v2 && v1 < v3)
|| (v2 > v3 && v2 < v1) || (v3 > v1 && v3 < v2)));
*has_wrapped = o1;
return v2;
}
static irqreturn_t sh_cmt_interrupt(int irq, void *dev_id)
{
struct sh_cmt_priv *p = dev_id;
/* clear flags */
sh_cmt_write(p, CMCSR, sh_cmt_read(p, CMCSR) & p->clear_bits);
/* update clock source counter to begin with if enabled
* the wrap flag should be cleared by the timer specific
* isr before we end up here.
*/
if (p->flags & FLAG_CLOCKSOURCE)
p->total_cycles += p->match_value;
if (!(p->flags & FLAG_REPROGRAM))
p->next_match_value = p->max_match_value;
p->flags |= FLAG_IRQCONTEXT;
if (p->flags & FLAG_CLOCKEVENT) {
if (!(p->flags & FLAG_SKIPEVENT)) {
if (p->ced.mode == CLOCK_EVT_MODE_ONESHOT) {
p->next_match_value = p->max_match_value;
p->flags |= FLAG_REPROGRAM;
}
p->ced.event_handler(&p->ced);
}
}
p->flags &= ~FLAG_SKIPEVENT;
if (p->flags & FLAG_REPROGRAM) {
p->flags &= ~FLAG_REPROGRAM;
sh_cmt_clock_event_program_verify(p, 1);
if (p->flags & FLAG_CLOCKEVENT)
if ((p->ced.mode == CLOCK_EVT_MODE_SHUTDOWN)
|| (p->match_value == p->next_match_value))
p->flags &= ~FLAG_REPROGRAM;
}
p->flags &= ~FLAG_IRQCONTEXT;
return IRQ_HANDLED;
}
static void sh_cmt_start_stop_ch(struct sh_cmt_priv *p, int start)
{
struct sh_timer_config *cfg = p->pdev->dev.platform_data;
unsigned long flags, value;
/* start stop register shared by multiple timer channels */
spin_lock_irqsave(&sh_cmt_lock, flags);
value = sh_cmt_read(p, CMSTR);
if (start)
value |= 1 << cfg->timer_bit;
else
value &= ~(1 << cfg->timer_bit);
sh_cmt_write(p, CMSTR, value);
spin_unlock_irqrestore(&sh_cmt_lock, flags);
}
static irqreturn_t sh_cmt_interrupt(int irq, void *dev_id)
{
struct sh_cmt_priv *p = dev_id;
sh_cmt_write(p, CMCSR, sh_cmt_read(p, CMCSR) & p->clear_bits);
if (p->flags & FLAG_CLOCKSOURCE)
p->total_cycles += p->match_value;
if (!(p->flags & FLAG_REPROGRAM))
p->next_match_value = p->max_match_value;
p->flags |= FLAG_IRQCONTEXT;
if (p->flags & FLAG_CLOCKEVENT) {
if (!(p->flags & FLAG_SKIPEVENT)) {
if (p->ced.mode == CLOCK_EVT_MODE_ONESHOT) {
p->next_match_value = p->max_match_value;
p->flags |= FLAG_REPROGRAM;
}
p->ced.event_handler(&p->ced);
}
}
p->flags &= ~FLAG_SKIPEVENT;
if (p->flags & FLAG_REPROGRAM) {
p->flags &= ~FLAG_REPROGRAM;
sh_cmt_clock_event_program_verify(p, 1);
if (p->flags & FLAG_CLOCKEVENT)
if ((p->ced.mode == CLOCK_EVT_MODE_SHUTDOWN)
|| (p->match_value == p->next_match_value))
p->flags &= ~FLAG_REPROGRAM;
}
p->flags &= ~FLAG_IRQCONTEXT;
return IRQ_HANDLED;
}
