1 files changed, 109 insertions, 43 deletions

diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index 01b886e6882..a8d7ea14f18 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -19,6 +19,8 @@
  *   - Two channels combine to create a free-running 32 bit counter
  *     with a base rate of 5+ MHz, packaged as a clocksource (with
  *     resolution better than 200 nsec).
+ *   - 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
@@ -54,12 +56,16 @@ static cycle_t tc_get_cycles(struct clocksource *cs)
 	return (upper << 16) | lower;
 }
 
+static cycle_t tc_get_cycles32(struct clocksource *cs)
+{
+	return __raw_readl(tcaddr + ATMEL_TC_REG(0, CV));
+}
+
 static struct clocksource clksrc = {
 	.name           = "tcb_clksrc",
 	.rating         = 200,
 	.read           = tc_get_cycles,
 	.mask           = CLOCKSOURCE_MASK(32),
-	.shift          = 18,
 	.flags		= CLOCK_SOURCE_IS_CONTINUOUS,
 };
 
@@ -151,7 +157,6 @@ static struct tc_clkevt_device 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,
 		.set_next_event	= tc_next_event,
@@ -175,41 +180,91 @@ static irqreturn_t ch2_irq(int irq, void *handle)
 
 static struct irqaction tc_irqaction = {
 	.name		= "tc_clkevt",
-	.flags		= IRQF_TIMER | IRQF_DISABLED,
+	.flags		= IRQF_TIMER,
 	.handler	= ch2_irq,
 };
 
-static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
 {
+	int ret;
 	struct clk *t2_clk = tc->clk[2];
 	int irq = tc->irq[2];
 
+	/* try to enable t2 clk to avoid future errors in mode change */
+	ret = clk_prepare_enable(t2_clk);
+	if (ret)
+		return ret;
+	clk_disable(t2_clk);
+
 	clkevt.regs = tc->regs;
 	clkevt.clk = t2_clk;
 	tc_irqaction.dev_id = &clkevt;
 
 	timer_clock = clk32k_divisor_idx;
 
-	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;
 	clkevt.clkevt.cpumask = cpumask_of(0);
 
-	setup_irq(irq, &tc_irqaction);
+	ret = setup_irq(irq, &tc_irqaction);
+	if (ret)
+		return ret;
+
+	clockevents_config_and_register(&clkevt.clkevt, 32768, 1, 0xffff);
 
-	clockevents_register_device(&clkevt.clkevt);
+	return ret;
 }
 
 #else /* !CONFIG_GENERIC_CLOCKEVENTS */
 
-static void __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
+static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
 {
 	/* NOTHING */
+	return 0;
 }
 
 #endif
 
+static void __init tcb_setup_dual_chan(struct atmel_tc *tc, int mck_divisor_idx)
+{
+	/* channel 0:  waveform mode, input mclk/8, clock TIOA0 on overflow */
+	__raw_writel(mck_divisor_idx			/* likely divide-by-8 */
+			| ATMEL_TC_WAVE
+			| ATMEL_TC_WAVESEL_UP		/* free-run */
+			| ATMEL_TC_ACPA_SET		/* TIOA0 rises at 0 */
+			| ATMEL_TC_ACPC_CLEAR,		/* (duty cycle 50%) */
+			tcaddr + ATMEL_TC_REG(0, CMR));
+	__raw_writel(0x0000, tcaddr + ATMEL_TC_REG(0, RA));
+	__raw_writel(0x8000, tcaddr + ATMEL_TC_REG(0, RC));
+	__raw_writel(0xff, tcaddr + ATMEL_TC_REG(0, IDR));	/* no irqs */
+	__raw_writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(0, CCR));
+
+	/* channel 1:  waveform mode, input TIOA0 */
+	__raw_writel(ATMEL_TC_XC1			/* input: TIOA0 */
+			| ATMEL_TC_WAVE
+			| ATMEL_TC_WAVESEL_UP,		/* free-run */
+			tcaddr + ATMEL_TC_REG(1, CMR));
+	__raw_writel(0xff, tcaddr + ATMEL_TC_REG(1, IDR));	/* no irqs */
+	__raw_writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(1, CCR));
+
+	/* chain channel 0 to channel 1*/
+	__raw_writel(ATMEL_TC_TC1XC1S_TIOA0, tcaddr + ATMEL_TC_BMR);
+	/* then reset all the timers */
+	__raw_writel(ATMEL_TC_SYNC, tcaddr + ATMEL_TC_BCR);
+}
+
+static void __init tcb_setup_single_chan(struct atmel_tc *tc, int mck_divisor_idx)
+{
+	/* channel 0:  waveform mode, input mclk/8 */
+	__raw_writel(mck_divisor_idx			/* likely divide-by-8 */
+			| ATMEL_TC_WAVE
+			| ATMEL_TC_WAVESEL_UP,		/* free-run */
+			tcaddr + ATMEL_TC_REG(0, CMR));
+	__raw_writel(0xff, tcaddr + ATMEL_TC_REG(0, IDR));	/* no irqs */
+	__raw_writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(0, CCR));
+
+	/* then reset all the timers */
+	__raw_writel(ATMEL_TC_SYNC, tcaddr + ATMEL_TC_BCR);
+}
+
 static int __init tcb_clksrc_init(void)
 {
 	static char bootinfo[] __initdata
@@ -222,6 +277,7 @@ static int __init tcb_clksrc_init(void)
 	int best_divisor_idx = -1;
 	int clk32k_divisor_idx = -1;
 	int i;
+	int ret;
 
 	tc = atmel_tc_alloc(CONFIG_ATMEL_TCB_CLKSRC_BLOCK, clksrc.name);
 	if (!tc) {
@@ -232,7 +288,11 @@ static int __init tcb_clksrc_init(void)
 	pdev = tc->pdev;
 
 	t0_clk = tc->clk[0];
-	clk_enable(t0_clk);
+	ret = clk_prepare_enable(t0_clk);
+	if (ret) {
+		pr_debug("can't enable T0 clk\n");
+		goto err_free_tc;
+	}
 
 	/* How fast will we be counting?  Pick something over 5 MHz.  */
 	rate = (u32) clk_get_rate(t0_clk);
@@ -256,47 +316,53 @@ static int __init tcb_clksrc_init(void)
 		best_divisor_idx = i;
 	}
 
-	clksrc.mult = clocksource_hz2mult(divided_rate, clksrc.shift);
 
 	printk(bootinfo, clksrc.name, CONFIG_ATMEL_TCB_CLKSRC_BLOCK,
 			divided_rate / 1000000,
 			((divided_rate + 500000) % 1000000) / 1000);
 
-	/* tclib will give us three clocks no matter what the
-	 * underlying platform supports.
-	 */
-	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 */
-			| ATMEL_TC_WAVE
-			| ATMEL_TC_WAVESEL_UP		/* free-run */
-			| ATMEL_TC_ACPA_SET		/* TIOA0 rises at 0 */
-			| ATMEL_TC_ACPC_CLEAR,		/* (duty cycle 50%) */
-			tcaddr + ATMEL_TC_REG(0, CMR));
-	__raw_writel(0x0000, tcaddr + ATMEL_TC_REG(0, RA));
-	__raw_writel(0x8000, tcaddr + ATMEL_TC_REG(0, RC));
-	__raw_writel(0xff, tcaddr + ATMEL_TC_REG(0, IDR));	/* no irqs */
-	__raw_writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(0, CCR));
-
-	/* channel 1:  waveform mode, input TIOA0 */
-	__raw_writel(ATMEL_TC_XC1			/* input: TIOA0 */
-			| ATMEL_TC_WAVE
-			| ATMEL_TC_WAVESEL_UP,		/* free-run */
-			tcaddr + ATMEL_TC_REG(1, CMR));
-	__raw_writel(0xff, tcaddr + ATMEL_TC_REG(1, IDR));	/* no irqs */
-	__raw_writel(ATMEL_TC_CLKEN, tcaddr + ATMEL_TC_REG(1, CCR));
-
-	/* chain channel 0 to channel 1, then reset all the timers */
-	__raw_writel(ATMEL_TC_TC1XC1S_TIOA0, tcaddr + ATMEL_TC_BMR);
-	__raw_writel(ATMEL_TC_SYNC, tcaddr + ATMEL_TC_BCR);
+	if (tc->tcb_config && tc->tcb_config->counter_width == 32) {
+		/* use apropriate function to read 32 bit counter */
+		clksrc.read = tc_get_cycles32;
+		/* setup ony channel 0 */
+		tcb_setup_single_chan(tc, best_divisor_idx);
+	} else {
+		/* tclib will give us three clocks no matter what the
+		 * underlying platform supports.
+		 */
+		ret = clk_prepare_enable(tc->clk[1]);
+		if (ret) {
+			pr_debug("can't enable T1 clk\n");
+			goto err_disable_t0;
+		}
+		/* setup both channel 0 & 1 */
+		tcb_setup_dual_chan(tc, best_divisor_idx);
+	}
 
 	/* and away we go! */
-	clocksource_register(&clksrc);
+	ret = clocksource_register_hz(&clksrc, divided_rate);
+	if (ret)
+		goto err_disable_t1;
 
 	/* channel 2:  periodic and oneshot timer support */
-	setup_clkevents(tc, clk32k_divisor_idx);
+	ret = setup_clkevents(tc, clk32k_divisor_idx);
+	if (ret)
+		goto err_unregister_clksrc;
 
 	return 0;
+
+err_unregister_clksrc:
+	clocksource_unregister(&clksrc);
+
+err_disable_t1:
+	if (!tc->tcb_config || tc->tcb_config->counter_width != 32)
+		clk_disable_unprepare(tc->clk[1]);
+
+err_disable_t0:
+	clk_disable_unprepare(t0_clk);
+
+err_free_tc:
+	atmel_tc_free(tc);
+	return ret;
 }
 arch_initcall(tcb_clksrc_init);