1 files changed, 59 insertions, 44 deletions

diff --git a/drivers/clocksource/timer-atmel-tcb.c b/drivers/clocksource/timer-atmel-tcb.c
index 7427b07495a8..787dbebbb432 100644
--- a/drivers/clocksource/timer-atmel-tcb.c
+++ b/drivers/clocksource/timer-atmel-tcb.c
@@ -27,9 +27,10 @@
  *   - Some chips support 32 bit counter. A single channel is used for
  *     this 32 bit free-running counter. the second channel is not used.
  *
- *   - The third channel may be used to provide a 16-bit clockevent
- *     source, used in either periodic or oneshot mode.  This runs
- *     at 32 KiHZ, and can handle delays of up to two seconds.
+ *   - The third channel may be used to provide a clockevent source, used in
+ *   either periodic or oneshot mode. For 16-bit counter its runs at 32 KiHZ,
+ *   and can handle delays of up to two seconds. For 32-bit counters, it runs at
+ *   the same rate as the clocksource
  *
  * REVISIT behavior during system suspend states... we should disable
  * all clocks and save the power.  Easily done for clockevent devices,
@@ -47,6 +48,8 @@ static struct
 } tcb_cache[3];
 static u32 bmr_cache;
 
+static const u8 atmel_tcb_divisors[] = { 2, 8, 32, 128 };
+
 static u64 tc_get_cycles(struct clocksource *cs)
 {
 	unsigned long	flags;
@@ -143,6 +146,7 @@ static unsigned long notrace tc_delay_timer_read32(void)
 struct tc_clkevt_device {
 	struct clock_event_device	clkevt;
 	struct clk			*clk;
+	u32				rate;
 	void __iomem			*regs;
 };
 
@@ -151,13 +155,6 @@ 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
- * tick rate can never be less than several dozen Hz (vs 0.5 Hz).
- *
- * A divided clock could be good for high resolution timers, since
- * 30.5 usec resolution can seem "low".
- */
 static u32 timer_clock;
 
 static int tc_shutdown(struct clock_event_device *d)
@@ -183,7 +180,7 @@ static int tc_set_oneshot(struct clock_event_device *d)
 
 	clk_enable(tcd->clk);
 
-	/* slow clock, count up to RC, then irq and stop */
+	/* count up to RC, then irq and stop */
 	writel(timer_clock | ATMEL_TC_CPCSTOP | ATMEL_TC_WAVE |
 		     ATMEL_TC_WAVESEL_UP_AUTO, regs + ATMEL_TC_REG(2, CMR));
 	writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER));
@@ -205,10 +202,10 @@ static int tc_set_periodic(struct clock_event_device *d)
 	 */
 	clk_enable(tcd->clk);
 
-	/* slow clock, count up to RC, then irq and restart */
+	/* count up to RC, then irq and restart */
 	writel(timer_clock | ATMEL_TC_WAVE | ATMEL_TC_WAVESEL_UP_AUTO,
 		     regs + ATMEL_TC_REG(2, CMR));
-	writel((32768 + HZ / 2) / HZ, tcaddr + ATMEL_TC_REG(2, RC));
+	writel((tcd->rate + HZ / 2) / HZ, tcaddr + ATMEL_TC_REG(2, RC));
 
 	/* Enable clock and interrupts on RC compare */
 	writel(ATMEL_TC_CPCS, regs + ATMEL_TC_REG(2, IER));
@@ -256,47 +253,55 @@ static irqreturn_t ch2_irq(int irq, void *handle)
 	return IRQ_NONE;
 }
 
-static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+static int __init setup_clkevents(struct atmel_tc *tc, int divisor_idx)
 {
 	int ret;
 	struct clk *t2_clk = tc->clk[2];
 	int irq = tc->irq[2];
-
-	ret = clk_prepare_enable(tc->slow_clk);
-	if (ret)
-		return ret;
+	int bits = tc->tcb_config->counter_width;
 
 	/* try to enable t2 clk to avoid future errors in mode change */
 	ret = clk_prepare_enable(t2_clk);
-	if (ret) {
-		clk_disable_unprepare(tc->slow_clk);
+	if (ret)
 		return ret;
-	}
-
-	clk_disable(t2_clk);
 
 	clkevt.regs = tc->regs;
 	clkevt.clk = t2_clk;
 
-	timer_clock = clk32k_divisor_idx;
+	if (bits == 32) {
+		timer_clock = divisor_idx;
+		clkevt.rate = clk_get_rate(t2_clk) / atmel_tcb_divisors[divisor_idx];
+	} else {
+		ret = clk_prepare_enable(tc->slow_clk);
+		if (ret) {
+			clk_disable_unprepare(t2_clk);
+			return ret;
+		}
+
+		clkevt.rate = clk_get_rate(tc->slow_clk);
+		timer_clock = ATMEL_TC_TIMER_CLOCK5;
+	}
+
+	clk_disable(t2_clk);
 
 	clkevt.clkevt.cpumask = cpumask_of(0);
 
 	ret = request_irq(irq, ch2_irq, IRQF_TIMER, "tc_clkevt", &clkevt);
 	if (ret) {
 		clk_unprepare(t2_clk);
-		clk_disable_unprepare(tc->slow_clk);
+		if (bits != 32)
+			clk_disable_unprepare(tc->slow_clk);
 		return ret;
 	}
 
-	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
+	clockevents_config_and_register(&clkevt.clkevt, clkevt.rate, 1, BIT(bits) - 1);
 
 	return ret;
 }
 
 #else /* !CONFIG_GENERIC_CLOCKEVENTS */
 
-static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+static int __init setup_clkevents(struct atmel_tc *tc, int divisor_idx)
 {
 	/* NOTHING */
 	return 0;
@@ -346,11 +351,23 @@ static void __init tcb_setup_single_chan(struct atmel_tc *tc, int mck_divisor_id
 	writel(ATMEL_TC_SYNC, tcaddr + ATMEL_TC_BCR);
 }
 
-static const u8 atmel_tcb_divisors[5] = { 2, 8, 32, 128, 0, };
+static struct atmel_tcb_config tcb_rm9200_config = {
+	.counter_width = 16,
+};
+
+static struct atmel_tcb_config tcb_sam9x5_config = {
+	.counter_width = 32,
+};
+
+static struct atmel_tcb_config tcb_sama5d2_config = {
+	.counter_width = 32,
+	.has_gclk = 1,
+};
 
 static const struct of_device_id atmel_tcb_of_match[] = {
-	{ .compatible = "atmel,at91rm9200-tcb", .data = (void *)16, },
-	{ .compatible = "atmel,at91sam9x5-tcb", .data = (void *)32, },
+	{ .compatible = "atmel,at91rm9200-tcb", .data = &tcb_rm9200_config, },
+	{ .compatible = "atmel,at91sam9x5-tcb", .data = &tcb_sam9x5_config, },
+	{ .compatible = "atmel,sama5d2-tcb", .data = &tcb_sama5d2_config, },
 	{ /* sentinel */ }
 };
 
@@ -362,7 +379,6 @@ static int __init tcb_clksrc_init(struct device_node *node)
 	u64 (*tc_sched_clock)(void);
 	u32 rate, divided_rate = 0;
 	int best_divisor_idx = -1;
-	int clk32k_divisor_idx = -1;
 	int bits;
 	int i;
 	int ret;
@@ -399,7 +415,11 @@ static int __init tcb_clksrc_init(struct device_node *node)
 	}
 
 	match = of_match_node(atmel_tcb_of_match, node->parent);
-	bits = (uintptr_t)match->data;
+	if (!match)
+		return -ENODEV;
+
+	tc.tcb_config = match->data;
+	bits = tc.tcb_config->counter_width;
 
 	for (i = 0; i < ARRAY_SIZE(tc.irq); i++)
 		writel(ATMEL_TC_ALL_IRQ, tc.regs + ATMEL_TC_REG(i, IDR));
@@ -412,22 +432,17 @@ static int __init tcb_clksrc_init(struct device_node *node)
 
 	/* How fast will we be counting?  Pick something over 5 MHz.  */
 	rate = (u32) clk_get_rate(t0_clk);
-	for (i = 0; i < ARRAY_SIZE(atmel_tcb_divisors); i++) {
+	i = 0;
+	if (tc.tcb_config->has_gclk)
+		i = 1;
+	for (; i < ARRAY_SIZE(atmel_tcb_divisors); i++) {
 		unsigned divisor = atmel_tcb_divisors[i];
 		unsigned tmp;
 
-		/* remember 32 KiHz clock for later */
-		if (!divisor) {
-			clk32k_divisor_idx = i;
-			continue;
-		}
-
 		tmp = rate / divisor;
 		pr_debug("TC: %u / %-3u [%d] --> %u\n", rate, divisor, i, tmp);
-		if (best_divisor_idx > 0) {
-			if (tmp < 5 * 1000 * 1000)
-				continue;
-		}
+		if ((best_divisor_idx >= 0) && (tmp < 5 * 1000 * 1000))
+			break;
 		divided_rate = tmp;
 		best_divisor_idx = i;
 	}
@@ -467,7 +482,7 @@ static int __init tcb_clksrc_init(struct device_node *node)
 		goto err_disable_t1;
 
 	/* channel 2:  periodic and oneshot timer support */
-	ret = setup_clkevents(&tc, clk32k_divisor_idx);
+	ret = setup_clkevents(&tc, best_divisor_idx);
 	if (ret)
 		goto err_unregister_clksrc;