The patch titled
atmel_tc clocksource/clockevent code (update)
has been added to the -mm tree. Its filename is
atmel_tc-clocksource-clockevent-code-update.patch
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------------------------------------------------------
Subject: atmel_tc clocksource/clockevent code (update)
From: David Brownell <david-b@xxxxxxxxxxx>
* Update to use new tclib API
* Replace open-coded do-while loop using goto with a real do-while loop
* Minor irq handler optimization: Load register base address from
dev_id instead of a global variable.
* Aggressively turn off clocks when the clockevent isn't being used
* Include the clockevent code on AT91RM9200 as well. The rating is
lower than the System Timer, so the clock will usually stay off.
* Don't assume that the number of clocks is always equal to the
number of irqs.
Signed-off-by: David Brownell <dbrownell@xxxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Haavard Skinnemoen <hskinnemoen@xxxxxxxxx>
Cc: Nicolas Ferre <nicolas.ferre@xxxxxxxxxxxxx>
Cc: Andrew Victor <linux@xxxxxxxxxxxx>
Cc: john stultz <johnstul@xxxxxxxxxx>
Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
drivers/clocksource/tcb_clksrc.c | 142 ++++++++++++++---------------
1 file changed, 72 insertions(+), 70 deletions(-)
diff -puN drivers/clocksource/tcb_clksrc.c~atmel_tc-clocksource-clockevent-code-update drivers/clocksource/tcb_clksrc.c
--- a/drivers/clocksource/tcb_clksrc.c~atmel_tc-clocksource-clockevent-code-update
+++ a/drivers/clocksource/tcb_clksrc.c
@@ -45,11 +45,10 @@ static cycle_t tc_get_cycles(void)
u32 lower, upper;
raw_local_irq_save(flags);
-retry:
- upper = __raw_readl(tcaddr + ATMEL_TC_REG(1, CV));
- lower = __raw_readl(tcaddr + ATMEL_TC_REG(0, CV));
- if (upper != __raw_readl(tcaddr + ATMEL_TC_REG(1, CV)))
- goto retry;
+ do {
+ upper = __raw_readl(tcaddr + ATMEL_TC_REG(1, CV));
+ lower = __raw_readl(tcaddr + ATMEL_TC_REG(0, CV));
+ } while (upper != __raw_readl(tcaddr + ATMEL_TC_REG(1, CV)));
raw_local_irq_restore(flags);
return (upper << 16) | lower;
@@ -65,18 +64,17 @@ static struct clocksource clksrc = {
};
#ifdef CONFIG_GENERIC_CLOCKEVENTS
-#define USE_TC_CLKEVT
-#endif
-#ifdef CONFIG_ARCH_AT91RM9200
-/* The AT91rm9200 system timer is a oneshot-capable 32k timer that's
- * always running ... configuring a TC channel to work the same way
- * would just waste some power.
- */
-#undef USE_TC_CLKEVT
-#endif
+struct tc_clkevt_device {
+ struct clock_event_device clkevt;
+ struct clk *clk;
+ void __iomem *regs;
+};
-#ifdef USE_TC_CLKEVT
+static struct tc_clkevt_device *to_tc_clkevt(struct clock_event_device *clkevt)
+{
+ return container_of(clkevt, struct tc_clkevt_device, clkevt);
+}
/* For now, we always use the 32K clock ... this optimizes for NO_HZ,
* because using one of the divided clocks would usually mean the
@@ -89,8 +87,15 @@ static u32 timer_clock;
static void tc_mode(enum clock_event_mode m, struct clock_event_device *d)
{
- __raw_writel(0xff, tcaddr + ATMEL_TC_REG(2, IDR));
- __raw_writel(ATMEL_TC_CLKDIS, tcaddr + ATMEL_TC_REG(2, CCR));
+ struct tc_clkevt_device *tcd = to_tc_clkevt(d);
+ void __iomem *regs = tcd->regs;
+
+ if (tcd->clkevt.mode == CLOCK_EVT_MODE_PERIODIC
+ || tcd->clkevt.mode == CLOCK_EVT_MODE_ONESHOT) {
+ __raw_writel(0xff, regs + ATMEL_TC_REG(2, IDR));
+ __raw_writel(ATMEL_TC_CLKDIS, regs + ATMEL_TC_REG(2, CCR));
+ clk_disable(tcd->clk);
+ }
switch (m) {
@@ -98,26 +103,30 @@ static void tc_mode(enum clock_event_mod
* of oneshot, we get lower overhead and improved accuracy.
*/
case CLOCK_EVT_MODE_PERIODIC:
+ clk_enable(tcd->clk);
+
/* slow clock, count up to RC, then irq and restart */
__raw_writel(timer_clock
| ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO,
- tcaddr + ATMEL_TC_REG(2, CMR));
+ regs + ATMEL_TC_REG(2, CMR));
__raw_writel((32768 + HZ/2) / HZ, tcaddr + ATMEL_TC_REG(2, RC));
/* Enable clock and interrupts on RC compare */
- __raw_writel(ATMEL_TC_CPCS, tcaddr + ATMEL_TC_REG(2, IER));
+ __raw_writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER));
/* go go gadget! */
__raw_writel(ATMEL_TC_CLKEN | ATMEL_TC_SWTRG,
- tcaddr + ATMEL_TC_REG(2, CCR));
+ regs + ATMEL_TC_REG(2, CCR));
break;
case CLOCK_EVT_MODE_ONESHOT:
+ clk_enable(tcd->clk);
+
/* slow clock, count up to RC, then irq and stop */
__raw_writel(timer_clock | ATMEL_TC_CPCSTOP
| ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO,
- tcaddr + ATMEL_TC_REG(2, CMR));
- __raw_writel(ATMEL_TC_CPCS, tcaddr + ATMEL_TC_REG(2, IER));
+ regs + ATMEL_TC_REG(2, CMR));
+ __raw_writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER));
/* set_next_event() configures and starts the timer */
break;
@@ -137,22 +146,28 @@ static int tc_next_event(unsigned long d
return 0;
}
-static struct clock_event_device clkevt = {
- .name = "tc_clkevt",
- .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
- .shift = 32,
- .rating = 125,
- .cpumask = CPU_MASK_CPU0,
- .set_next_event = tc_next_event,
- .set_mode = tc_mode,
+static struct tc_clkevt_device clkevt = {
+ .clkevt = {
+ .name = "tc_clkevt",
+ .features = CLOCK_EVT_FEAT_PERIODIC
+ | CLOCK_EVT_FEAT_ONESHOT,
+ .shift = 32,
+ /* Should be lower than at91rm9200's system timer */
+ .rating = 125,
+ .cpumask = CPU_MASK_CPU0,
+ .set_next_event = tc_next_event,
+ .set_mode = tc_mode,
+ },
};
static irqreturn_t ch2_irq(int irq, void *handle)
{
- unsigned int sr = __raw_readl(tcaddr + ATMEL_TC_REG(2, SR));
+ struct tc_clkevt_device *dev = handle;
+ unsigned int sr;
+ sr = __raw_readl(dev->regs + ATMEL_TC_REG(2, SR));
if (sr & ATMEL_TC_CPCS) {
- clkevt.event_handler(&clkevt);
+ dev->clkevt.event_handler(&dev->clkevt);
return IRQ_HANDLED;
}
@@ -165,37 +180,32 @@ static struct irqaction tc_irqaction = {
.handler = ch2_irq,
};
-static void __init setup_clkevents(struct platform_device *pdev,
+static void __init setup_clkevents(struct atmel_tc *tc,
struct clk *t0_clk, int clk32k_divisor_idx)
{
- struct clk *t2_clk = clk_get(&pdev->dev, "t2_clk");
- int irq;
-
- /* SOCs have either one IRQ and one clock for the whole
- * TC block; or one each per channel. We use channel 2.
- */
- if (IS_ERR(t2_clk)) {
- t2_clk = t0_clk;
- irq = platform_get_irq(pdev, 0);
- } else {
- irq = platform_get_irq(pdev, 2);
- clk_enable(t2_clk);
- }
+ struct platform_device *pdev = tc->pdev;
+ struct clk *t2_clk = tc->clk[2];
+ int irq = tc->irq[2];
+
+ clkevt.regs = tc->regs;
+ clkevt.clk = t2_clk;
+ tc_irqaction.dev_id = &clkevt;
timer_clock = clk32k_divisor_idx;
- clkevt.mult = div_sc(32768, NSEC_PER_SEC, clkevt.shift);
- clkevt.max_delta_ns = clockevent_delta2ns(0xffff, &clkevt);
- clkevt.min_delta_ns = clockevent_delta2ns(1, &clkevt) + 1;
+ clkevt.clkevt.mult = div_sc(32768, NSEC_PER_SEC, clkevt.clkevt.shift);
+ clkevt.clkevt.max_delta_ns
+ = clockevent_delta2ns(0xffff, &clkevt.clkevt);
+ clkevt.clkevt.min_delta_ns = clockevent_delta2ns(1, &clkevt.clkevt) + 1;
setup_irq(irq, &tc_irqaction);
- clockevents_register_device(&clkevt);
+ clockevents_register_device(&clkevt.clkevt);
}
-#else /* !USE_TC_CLKEVT */
+#else /* !CONFIG_GENERIC_CLOCKEVENTS */
-static void __init setup_clkevents(struct platform_device *pdev,
+static void __init setup_clkevents(struct atmel_tc *tc,
struct clk *t0_clk, int clk32k_divisor_idx)
{
/* NOTHING */
@@ -209,26 +219,22 @@ static int __init tcb_clksrc_init(void)
= KERN_DEBUG "%s: tc%d at %d.%03d MHz\n";
struct platform_device *pdev;
+ struct atmel_tc *tc;
struct clk *t0_clk, *t1_clk;
u32 rate, divided_rate = 0;
int best_divisor_idx = -1;
int clk32k_divisor_idx = -1;
int i;
- struct resource *iomem;
- pdev = atmel_tc_alloc(CONFIG_ATMEL_TCB_CLKSRC_BLOCK, &iomem);
- if (pdev == NULL) {
+ tc = atmel_tc_alloc(CONFIG_ATMEL_TCB_CLKSRC_BLOCK, clksrc.name);
+ if (!tc) {
pr_debug("can't alloc TC for clocksource\n");
return -ENODEV;
}
- rename_region(iomem, clksrc.name);
- tcaddr = ioremap(iomem->start, 256);
+ tcaddr = tc->regs;
+ pdev = tc->pdev;
- t0_clk = clk_get(&pdev->dev, "t0_clk");
- if (IS_ERR(t0_clk)) {
- atmel_tc_free(pdev);
- return PTR_ERR(t0_clk);
- }
+ t0_clk = tc->clk[0];
clk_enable(t0_clk);
/* How fast will we be counting? Pick something over 5 MHz. */
@@ -259,14 +265,10 @@ static int __init tcb_clksrc_init(void)
divided_rate / 1000000,
((divided_rate + 500000) % 1000000) / 1000);
- /* Some platforms (like at91rm9200, at91sam9260, etc) have one clock
- * (and IRQ) per timer. Others (at91sam9263, ap700x, etc) don't.
+ /* tclib will give us three clocks no matter what the
+ * underlying platform supports.
*/
- t1_clk = clk_get(&pdev->dev, "t1_clk");
- if (IS_ERR(t1_clk))
- t1_clk = t0_clk;
- else
- clk_enable(t1_clk);
+ clk_enable(tc->clk[1]);
/* channel 0: waveform mode, input mclk/8, clock TIOA0 on overflow */
__raw_writel(best_divisor_idx /* likely divide-by-8 */
@@ -296,7 +298,7 @@ static int __init tcb_clksrc_init(void)
clocksource_register(&clksrc);
/* channel 2: periodic and oneshot timer support */
- setup_clkevents(pdev, t0_clk, clk32k_divisor_idx);
+ setup_clkevents(tc, t0_clk, clk32k_divisor_idx);
return 0;
}
_
Patches currently in -mm which might be from david-b@xxxxxxxxxxx are
git-acpi.patch
at91-correct-at91sam9263ek-lcd-power-gpio-pin.patch
git-avr32.patch
input-add-debouncing-for-generic-gpio-input-device-gpio_keyc.patch
usb-net-asix-does-not-really-need-10-100mbit.patch
spi-pxa2xx_spi-sparse-fixes.patch
rtc-avoid-legacy-drivers-with-generic-framework.patch
rtc-isl1208-new-style-conversion-and-minor-bug-fixes.patch
rtc-isl1208-new-style-conversion-and-minor-bug-fixes-checkpatch-fixes.patch
rtc-pcf8563-new-style-conversion.patch
rtc-pcf8563-new-style-conversion-checkpatch-fixes.patch
rtc-pcf8563-new-style-conversion-checkpatch-fixes-fix.patch
rtc-x1205-new-style-conversion.patch
rtc-x1205-new-style-conversion-checkpatch-fixes.patch
rtc-silence-section-mismatch-warning-in-rtc-test.patch
make-ds1511_rtc_readset_time-static.patch
rtc-replace-remaining-__function__-occurrences.patch
atmel_tc-library.patch
atmel_tc-library-update.patch
atmel_tc-clocksource-clockevent-code.patch
atmel_tc-clocksource-clockevent-code-update.patch
remove-duplicated-unlikely-in-is_err.patch
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