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path: root/drivers/clocksource/exynos_mct.c
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Diffstat (limited to 'drivers/clocksource/exynos_mct.c')
-rw-r--r--drivers/clocksource/exynos_mct.c119
1 files changed, 93 insertions, 26 deletions
diff --git a/drivers/clocksource/exynos_mct.c b/drivers/clocksource/exynos_mct.c
index 6db3d5511b0f..da09f467a6bb 100644
--- a/drivers/clocksource/exynos_mct.c
+++ b/drivers/clocksource/exynos_mct.c
@@ -33,7 +33,7 @@
#define EXYNOS4_MCT_G_INT_ENB EXYNOS4_MCTREG(0x248)
#define EXYNOS4_MCT_G_WSTAT EXYNOS4_MCTREG(0x24C)
#define _EXYNOS4_MCT_L_BASE EXYNOS4_MCTREG(0x300)
-#define EXYNOS4_MCT_L_BASE(x) (_EXYNOS4_MCT_L_BASE + (0x100 * x))
+#define EXYNOS4_MCT_L_BASE(x) (_EXYNOS4_MCT_L_BASE + (0x100 * (x)))
#define EXYNOS4_MCT_L_MASK (0xffffff00)
#define MCT_L_TCNTB_OFFSET (0x00)
@@ -60,27 +60,20 @@
#define MCT_CLKEVENTS_RATING 350
#endif
+/* There are four Global timers starting with 0 offset */
+#define MCT_G0_IRQ 0
+/* Local timers count starts after global timer count */
+#define MCT_L0_IRQ 4
+/* Max number of IRQ as per DT binding document */
+#define MCT_NR_IRQS 20
+/* Max number of local timers */
+#define MCT_NR_LOCAL (MCT_NR_IRQS - MCT_L0_IRQ)
+
enum {
MCT_INT_SPI,
MCT_INT_PPI
};
-enum {
- MCT_G0_IRQ,
- MCT_G1_IRQ,
- MCT_G2_IRQ,
- MCT_G3_IRQ,
- MCT_L0_IRQ,
- MCT_L1_IRQ,
- MCT_L2_IRQ,
- MCT_L3_IRQ,
- MCT_L4_IRQ,
- MCT_L5_IRQ,
- MCT_L6_IRQ,
- MCT_L7_IRQ,
- MCT_NR_IRQS,
-};
-
static void __iomem *reg_base;
static unsigned long clk_rate;
static unsigned int mct_int_type;
@@ -89,7 +82,11 @@ static int mct_irqs[MCT_NR_IRQS];
struct mct_clock_event_device {
struct clock_event_device evt;
unsigned long base;
- char name[10];
+ /**
+ * The length of the name must be adjusted if number of
+ * local timer interrupts grow over two digits
+ */
+ char name[11];
};
static void exynos4_mct_write(unsigned int value, unsigned long offset)
@@ -238,9 +235,16 @@ static cycles_t exynos4_read_current_timer(void)
}
#endif
-static int __init exynos4_clocksource_init(void)
+static int __init exynos4_clocksource_init(bool frc_shared)
{
- exynos4_mct_frc_start();
+ /*
+ * When the frc is shared, the main processor should have already
+ * turned it on and we shouldn't be writing to TCON.
+ */
+ if (frc_shared)
+ mct_frc.resume = NULL;
+ else
+ exynos4_mct_frc_start();
#if defined(CONFIG_ARM)
exynos4_delay_timer.read_current_timer = &exynos4_read_current_timer;
@@ -454,7 +458,6 @@ static int exynos4_mct_starting_cpu(unsigned int cpu)
per_cpu_ptr(&percpu_mct_tick, cpu);
struct clock_event_device *evt = &mevt->evt;
- mevt->base = EXYNOS4_MCT_L_BASE(cpu);
snprintf(mevt->name, sizeof(mevt->name), "mct_tick%d", cpu);
evt->name = mevt->name;
@@ -493,7 +496,6 @@ static int exynos4_mct_dying_cpu(unsigned int cpu)
per_cpu_ptr(&percpu_mct_tick, cpu);
struct clock_event_device *evt = &mevt->evt;
- evt->set_state_shutdown(evt);
if (mct_int_type == MCT_INT_SPI) {
if (evt->irq != -1)
disable_irq_nosync(evt->irq);
@@ -525,8 +527,17 @@ static int __init exynos4_timer_resources(struct device_node *np)
return 0;
}
+/**
+ * exynos4_timer_interrupts - initialize MCT interrupts
+ * @np: device node for MCT
+ * @int_type: interrupt type, MCT_INT_PPI or MCT_INT_SPI
+ * @local_idx: array mapping CPU numbers to local timer indices
+ * @nr_local: size of @local_idx array
+ */
static int __init exynos4_timer_interrupts(struct device_node *np,
- unsigned int int_type)
+ unsigned int int_type,
+ const u32 *local_idx,
+ size_t nr_local)
{
int nr_irqs, i, err, cpu;
@@ -541,6 +552,11 @@ static int __init exynos4_timer_interrupts(struct device_node *np,
* irqs are specified.
*/
nr_irqs = of_irq_count(np);
+ if (nr_irqs > ARRAY_SIZE(mct_irqs)) {
+ pr_err("exynos-mct: too many (%d) interrupts configured in DT\n",
+ nr_irqs);
+ nr_irqs = ARRAY_SIZE(mct_irqs);
+ }
for (i = MCT_L0_IRQ; i < nr_irqs; i++)
mct_irqs[i] = irq_of_parse_and_map(np, i);
@@ -553,11 +569,22 @@ static int __init exynos4_timer_interrupts(struct device_node *np,
mct_irqs[MCT_L0_IRQ], err);
} else {
for_each_possible_cpu(cpu) {
- int mct_irq = mct_irqs[MCT_L0_IRQ + cpu];
+ int mct_irq;
+ unsigned int irq_idx;
struct mct_clock_event_device *pcpu_mevt =
per_cpu_ptr(&percpu_mct_tick, cpu);
+ if (cpu >= nr_local) {
+ err = -EINVAL;
+ goto out_irq;
+ }
+
+ irq_idx = MCT_L0_IRQ + local_idx[cpu];
+
pcpu_mevt->evt.irq = -1;
+ if (irq_idx >= ARRAY_SIZE(mct_irqs))
+ break;
+ mct_irq = mct_irqs[irq_idx];
irq_set_status_flags(mct_irq, IRQ_NOAUTOEN);
if (request_irq(mct_irq,
@@ -573,6 +600,17 @@ static int __init exynos4_timer_interrupts(struct device_node *np,
}
}
+ for_each_possible_cpu(cpu) {
+ struct mct_clock_event_device *mevt = per_cpu_ptr(&percpu_mct_tick, cpu);
+
+ if (cpu >= nr_local) {
+ err = -EINVAL;
+ goto out_irq;
+ }
+
+ mevt->base = EXYNOS4_MCT_L_BASE(local_idx[cpu]);
+ }
+
/* Install hotplug callbacks which configure the timer on this CPU */
err = cpuhp_setup_state(CPUHP_AP_EXYNOS4_MCT_TIMER_STARTING,
"clockevents/exynos4/mct_timer:starting",
@@ -602,20 +640,49 @@ out_irq:
static int __init mct_init_dt(struct device_node *np, unsigned int int_type)
{
+ bool frc_shared = of_property_read_bool(np, "samsung,frc-shared");
+ u32 local_idx[MCT_NR_LOCAL] = {0};
+ int nr_local;
int ret;
+ nr_local = of_property_count_u32_elems(np, "samsung,local-timers");
+ if (nr_local == 0)
+ return -EINVAL;
+ if (nr_local > 0) {
+ if (nr_local > ARRAY_SIZE(local_idx))
+ return -EINVAL;
+
+ ret = of_property_read_u32_array(np, "samsung,local-timers",
+ local_idx, nr_local);
+ if (ret)
+ return ret;
+ } else {
+ int i;
+
+ nr_local = ARRAY_SIZE(local_idx);
+ for (i = 0; i < nr_local; i++)
+ local_idx[i] = i;
+ }
+
ret = exynos4_timer_resources(np);
if (ret)
return ret;
- ret = exynos4_timer_interrupts(np, int_type);
+ ret = exynos4_timer_interrupts(np, int_type, local_idx, nr_local);
if (ret)
return ret;
- ret = exynos4_clocksource_init();
+ ret = exynos4_clocksource_init(frc_shared);
if (ret)
return ret;
+ /*
+ * When the FRC is shared with a main processor, this secondary
+ * processor cannot use the global comparator.
+ */
+ if (frc_shared)
+ return 0;
+
return exynos4_clockevent_init();
}