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ramips: improve systick timer

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when sleep mode is disable use MIPS as clocksource and clockevent instead of systick.
because MIPS timer has higher resolution 5ns less than systick 20us and
larger counter bits 32 > 16.
clean interrupt by write compare register at isr.
fix typo cause sleep mode not enable.

Signed-off-by: Michael Lee <igvtee@gmail.com>

SVN-Revision: 47122
This commit is contained in:
John Crispin 2015-10-05 10:27:09 +00:00
parent 10f75a2b7f
commit b4db6d29d3
1 changed files with 145 additions and 6 deletions
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151
target/linux/ramips/patches-3.18/0066-cevt.patch
View file

@ -1,12 +1,151 @@
--- a/arch/mips/ralink/cevt-rt3352.c
+++ b/arch/mips/ralink/cevt-rt3352.c
@@ -53,8 +53,7 @@ static int systick_next_event(unsigned l
@@ -45,18 +45,33 @@ static void (*systick_freq_scaling)(stru
static void systick_set_clock_mode(enum clock_event_mode mode,
struct clock_event_device *evt);
+static inline unsigned int read_count(struct systick_device *sdev)
+{
+ return ioread32(sdev->membase + SYSTICK_COUNT);
+}
+
+static inline unsigned int read_compare(struct systick_device *sdev)
+{
+ return ioread32(sdev->membase + SYSTICK_COMPARE);
+}
+
+static inline void write_compare(struct systick_device *sdev, unsigned int val)
+{
+ iowrite32(val, sdev->membase + SYSTICK_COMPARE);
+}
+
static int systick_next_event(unsigned long delta,
struct clock_event_device *evt)
{
struct systick_device *sdev;
- u32 count;
+ int res;
sdev = container_of(evt, struct systick_device, dev);
count = ioread32(sdev->membase + SYSTICK_COUNT);
- count = ioread32(sdev->membase + SYSTICK_COUNT);
- count = (count + delta) % SYSTICK_FREQ;
- iowrite32(count, sdev->membase + SYSTICK_COMPARE);
+ iowrite32(count + delta, sdev->membase + SYSTICK_COMPARE);
return 0;
+ delta += read_count(sdev);
+ write_compare(sdev, delta);
+ res = ((int)(read_count(sdev) - delta) >= 0) ? -ETIME : 0;
- return 0;
+ return res;
}
static void systick_event_handler(struct clock_event_device *dev)
@@ -66,20 +81,25 @@ static void systick_event_handler(struct
static irqreturn_t systick_interrupt(int irq, void *dev_id)
{
- struct clock_event_device *dev = (struct clock_event_device *) dev_id;
+ int ret = 0;
+ struct clock_event_device *cdev;
+ struct systick_device *sdev;
- dev->event_handler(dev);
+ if (read_c0_cause() & STATUSF_IP7) {
+ cdev = (struct clock_event_device *) dev_id;
+ sdev = container_of(cdev, struct systick_device, dev);
+
+ /* Clear Count/Compare Interrupt */
+ write_compare(sdev, read_compare(sdev));
+ cdev->event_handler(cdev);
+ ret = 1;
+ }
- return IRQ_HANDLED;
+ return IRQ_RETVAL(ret);
}
static struct systick_device systick = {
.dev = {
- /*
- * cevt-r4k uses 300, make sure systick
- * gets used if available
- */
- .rating = 310,
.features = CLOCK_EVT_FEAT_ONESHOT,
.set_next_event = systick_next_event,
.set_mode = systick_set_clock_mode,
@@ -126,13 +146,14 @@ static void systick_set_clock_mode(enum
systick_freq_scaling(sdev, 1);
break;
+ case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
if (systick_freq_scaling)
systick_freq_scaling(sdev, 0);
if (sdev->irq_requested)
- free_irq(systick.dev.irq, &systick_irqaction);
+ remove_irq(systick.dev.irq, &systick_irqaction);
sdev->irq_requested = 0;
- iowrite32(0, systick.membase + SYSTICK_CONFIG);
+ iowrite32(CFG_CNT_EN, systick.membase + SYSTICK_CONFIG);
break;
default:
@@ -142,38 +163,45 @@ static void systick_set_clock_mode(enum
}
static const struct of_device_id systick_match[] = {
- { .compatible = "ralink,mt7620-systick", .data = mt7620_freq_scaling},
+ { .compatible = "ralink,mt7620a-systick", .data = mt7620_freq_scaling},
{},
};
static void __init ralink_systick_init(struct device_node *np)
{
const struct of_device_id *match;
+ int rating = 200;
systick.membase = of_iomap(np, 0);
if (!systick.membase)
return;
match = of_match_node(systick_match, np);
- if (match)
+ if (match) {
systick_freq_scaling = match->data;
+ /*
+ * cevt-r4k uses 300, make sure systick
+ * gets used if available
+ */
+ rating = 310;
+ }
- systick_irqaction.name = np->name;
- systick.dev.name = np->name;
- clockevents_calc_mult_shift(&systick.dev, SYSTICK_FREQ, 60);
- systick.dev.max_delta_ns = clockevent_delta2ns(0x7fff, &systick.dev);
- systick.dev.min_delta_ns = clockevent_delta2ns(0x3, &systick.dev);
+ /* enable counter than register clock source */
+ iowrite32(CFG_CNT_EN, systick.membase + SYSTICK_CONFIG);
+ clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
+ SYSTICK_FREQ, rating, 16, clocksource_mmio_readl_up);
+
+ /* register clock event */
systick.dev.irq = irq_of_parse_and_map(np, 0);
if (!systick.dev.irq) {
pr_err("%s: request_irq failed", np->name);
return;
}
-
- clocksource_mmio_init(systick.membase + SYSTICK_COUNT, np->name,
- SYSTICK_FREQ, 301, 16, clocksource_mmio_readl_up);
-
- clockevents_register_device(&systick.dev);
-
+ systick_irqaction.name = np->name;
+ systick.dev.name = np->name;
+ systick.dev.rating = rating;
+ systick.dev.cpumask = cpumask_of(0);
+ clockevents_config_and_register(&systick.dev, SYSTICK_FREQ, 0x3, 0x7fff);
pr_info("%s: running - mult: %d, shift: %d\n",
np->name, systick.dev.mult, systick.dev.shift);
}