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authorFrancesco Virlinzi <francesco.virlinzi@st.com>2008-09-05 16:40:22 +0900
committerPaul Mundt <lethal@linux-sh.org>2008-09-08 10:35:05 +0900
commit61c66387e640abc0e0aa11519bc48ff9bb50580a (patch)
tree40e6986a00524fec360ea082324d76c0f41c58e8 /arch/sh/kernel/timers
parentb6ad1e8c3f76fcc5dee506d5e79e752d296ff745 (diff)
sh: fix the TMU code to allow a fully running NO_HZ system
This patch fixes the TMU code to allow NO_HZ to work on sh Signed-off-by: Francesco Virlinzi <francesco.virlinzi@st.com> Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/kernel/timers')
-rw-r--r--arch/sh/kernel/timers/timer-tmu.c177
1 files changed, 119 insertions, 58 deletions
diff --git a/arch/sh/kernel/timers/timer-tmu.c b/arch/sh/kernel/timers/timer-tmu.c
index 1ca9ad49b54..aaaf90d06b8 100644
--- a/arch/sh/kernel/timers/timer-tmu.c
+++ b/arch/sh/kernel/timers/timer-tmu.c
@@ -28,43 +28,90 @@
#define TMU_TOCR_INIT 0x00
#define TMU_TCR_INIT 0x0020
-static int tmu_timer_start(void)
+#define TMU0 (0)
+#define TMU1 (1)
+
+static inline void _tmu_start(int tmu_num)
{
- ctrl_outb(ctrl_inb(TMU_012_TSTR) | 0x3, TMU_012_TSTR);
- return 0;
+ ctrl_outb(ctrl_inb(TMU_012_TSTR) | (0x1<<tmu_num), TMU_012_TSTR);
}
-static void tmu0_timer_set_interval(unsigned long interval, unsigned int reload)
+static inline void _tmu_set_irq(int tmu_num, int enabled)
{
- ctrl_outl(interval, TMU0_TCNT);
+ register unsigned long tmu_tcr = TMU0_TCR + (0xc*tmu_num);
+ ctrl_outw( (enabled ? ctrl_inw(tmu_tcr) | (1<<5) : ctrl_inw(tmu_tcr) & ~(1<<5)), tmu_tcr);
+}
- /*
- * TCNT reloads from TCOR on underflow, clear it if we don't
- * intend to auto-reload
- */
- if (reload)
- ctrl_outl(interval, TMU0_TCOR);
- else
- ctrl_outl(0, TMU0_TCOR);
+static inline void _tmu_stop(int tmu_num)
+{
+ ctrl_outb(ctrl_inb(TMU_012_TSTR) & ~(0x1<<tmu_num), TMU_012_TSTR);
+}
+
+static inline void _tmu_clear_status(int tmu_num)
+{
+ register unsigned long tmu_tcr = TMU0_TCR + (0xc*tmu_num);
+ /* Clear UNF bit */
+ ctrl_outw(ctrl_inw(tmu_tcr) & ~0x100, tmu_tcr);
+}
- tmu_timer_start();
+static inline unsigned long _tmu_read(int tmu_num)
+{
+ return ctrl_inl(TMU0_TCNT+0xC*tmu_num);
+}
+
+static int tmu_timer_start(void)
+{
+ _tmu_start(TMU0);
+ _tmu_start(TMU1);
+ _tmu_set_irq(TMU0,1);
+ return 0;
}
static int tmu_timer_stop(void)
{
- ctrl_outb(ctrl_inb(TMU_012_TSTR) & ~0x3, TMU_012_TSTR);
+ _tmu_stop(TMU0);
+ _tmu_stop(TMU1);
+ _tmu_clear_status(TMU0);
return 0;
}
+/*
+ * also when the module_clk is scaled the TMU1
+ * will show the same frequency
+ */
+static int tmus_are_scaled;
+
static cycle_t tmu_timer_read(void)
{
- return ~ctrl_inl(TMU1_TCNT);
+ return ((cycle_t)(~_tmu_read(TMU1)))<<tmus_are_scaled;
+}
+
+
+static unsigned long tmu_latest_interval[3];
+static void tmu_timer_set_interval(int tmu_num, unsigned long interval, unsigned int reload)
+{
+ unsigned long tmu_tcnt = TMU0_TCNT + tmu_num*0xC;
+ unsigned long tmu_tcor = TMU0_TCOR + tmu_num*0xC;
+
+ _tmu_stop(tmu_num);
+
+ ctrl_outl(interval, tmu_tcnt);
+ tmu_latest_interval[tmu_num] = interval;
+
+ /*
+ * TCNT reloads from TCOR on underflow, clear it if we don't
+ * intend to auto-reload
+ */
+ ctrl_outl( reload ? interval : 0 , tmu_tcor);
+
+ _tmu_start(tmu_num);
}
static int tmu_set_next_event(unsigned long cycles,
struct clock_event_device *evt)
{
- tmu0_timer_set_interval(cycles, 1);
+ tmu_timer_set_interval(TMU0,cycles, evt->mode == CLOCK_EVT_MODE_PERIODIC);
+ _tmu_set_irq(TMU0,1);
return 0;
}
@@ -96,12 +143,8 @@ static struct clock_event_device tmu0_clockevent = {
static irqreturn_t tmu_timer_interrupt(int irq, void *dummy)
{
struct clock_event_device *evt = &tmu0_clockevent;
- unsigned long timer_status;
-
- /* Clear UNF bit */
- timer_status = ctrl_inw(TMU0_TCR);
- timer_status &= ~0x100;
- ctrl_outw(timer_status, TMU0_TCR);
+ _tmu_clear_status(TMU0);
+ _tmu_set_irq(TMU0,tmu0_clockevent.mode != CLOCK_EVT_MODE_ONESHOT);
evt->event_handler(evt);
@@ -109,56 +152,73 @@ static irqreturn_t tmu_timer_interrupt(int irq, void *dummy)
}
static struct irqaction tmu0_irq = {
- .name = "periodic timer",
+ .name = "periodic/oneshot timer",
.handler = tmu_timer_interrupt,
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.mask = CPU_MASK_NONE,
};
-static void tmu0_clk_init(struct clk *clk)
+static void __init tmu_clk_init(struct clk *clk)
{
- u8 divisor = TMU_TCR_INIT & 0x7;
- ctrl_outw(TMU_TCR_INIT, TMU0_TCR);
- clk->rate = clk->parent->rate / (4 << (divisor << 1));
+ u8 divisor = TMU_TCR_INIT & 0x7;
+ int tmu_num = clk->name[3]-'0';
+ ctrl_outw(TMU_TCR_INIT, TMU0_TCR+(tmu_num*0xC));
+ clk->rate = clk_get_rate(clk->parent) / (4 << (divisor << 1));
}
-static void tmu0_clk_recalc(struct clk *clk)
+static void tmu_clk_recalc(struct clk *clk)
{
- u8 divisor = ctrl_inw(TMU0_TCR) & 0x7;
- clk->rate = clk->parent->rate / (4 << (divisor << 1));
-}
+ int tmu_num = clk->name[3]-'0';
+ unsigned long prev_rate = clk_get_rate(clk);
+ unsigned long flags;
+ u8 divisor = ctrl_inw(TMU0_TCR+tmu_num*0xC) & 0x7;
+ clk->rate = clk_get_rate(clk->parent) / (4 << (divisor << 1));
-static struct clk_ops tmu0_clk_ops = {
- .init = tmu0_clk_init,
- .recalc = tmu0_clk_recalc,
-};
+ if(prev_rate==clk_get_rate(clk))
+ return;
-static struct clk tmu0_clk = {
- .name = "tmu0_clk",
- .ops = &tmu0_clk_ops,
-};
+ if(tmu_num)
+ return; /* No more work on TMU1 */
-static void tmu1_clk_init(struct clk *clk)
-{
- u8 divisor = TMU_TCR_INIT & 0x7;
- ctrl_outw(divisor, TMU1_TCR);
- clk->rate = clk->parent->rate / (4 << (divisor << 1));
-}
+ local_irq_save(flags);
+ tmus_are_scaled = (prev_rate > clk->rate);
-static void tmu1_clk_recalc(struct clk *clk)
-{
- u8 divisor = ctrl_inw(TMU1_TCR) & 0x7;
- clk->rate = clk->parent->rate / (4 << (divisor << 1));
+ _tmu_stop(TMU0);
+
+ tmu0_clockevent.mult = div_sc(clk->rate, NSEC_PER_SEC,
+ tmu0_clockevent.shift);
+ tmu0_clockevent.max_delta_ns =
+ clockevent_delta2ns(-1, &tmu0_clockevent);
+ tmu0_clockevent.min_delta_ns =
+ clockevent_delta2ns(1, &tmu0_clockevent);
+
+ if (tmus_are_scaled)
+ tmu_latest_interval[TMU0] >>= 1;
+ else
+ tmu_latest_interval[TMU0] <<= 1;
+
+ tmu_timer_set_interval(TMU0,
+ tmu_latest_interval[TMU0],
+ tmu0_clockevent.mode == CLOCK_EVT_MODE_PERIODIC);
+
+ _tmu_start(TMU0);
+
+ local_irq_restore(flags);
}
-static struct clk_ops tmu1_clk_ops = {
- .init = tmu1_clk_init,
- .recalc = tmu1_clk_recalc,
+static struct clk_ops tmu_clk_ops = {
+ .init = tmu_clk_init,
+ .recalc = tmu_clk_recalc,
+};
+
+static struct clk tmu0_clk = {
+ .name = "tmu0_clk",
+ .ops = &tmu_clk_ops,
};
static struct clk tmu1_clk = {
.name = "tmu1_clk",
- .ops = &tmu1_clk_ops,
+ .ops = &tmu_clk_ops,
};
static int tmu_timer_init(void)
@@ -189,11 +249,12 @@ static int tmu_timer_init(void)
frequency = clk_get_rate(&tmu0_clk);
interval = (frequency + HZ / 2) / HZ;
- sh_hpt_frequency = clk_get_rate(&tmu1_clk);
- ctrl_outl(~0, TMU1_TCNT);
- ctrl_outl(~0, TMU1_TCOR);
+ tmu_timer_set_interval(TMU0,interval, 1);
+ tmu_timer_set_interval(TMU1,~0,1);
- tmu0_timer_set_interval(interval, 1);
+ _tmu_start(TMU1);
+
+ sh_hpt_frequency = clk_get_rate(&tmu1_clk);
tmu0_clockevent.mult = div_sc(frequency, NSEC_PER_SEC,
tmu0_clockevent.shift);