Merge tag 'at91-cleanup-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux into next/drivers

Merge "First batch of cleanups for 4.4:" from Alexandre Belloni:
 - properly get the slow clock from timer-atmel-st, tcb_clksrc and pwm-atmel-tcb
 - small fix in an error path for tcb_clksrc

* tag 'at91-cleanup-4.4' of git://git.kernel.org/pub/scm/linux/kernel/git/abelloni/linux:
  misc: atmel_tclib: get and use slow clock
  clocksource: tcb_clksrc: fix setup_clkevents error path
  clocksource: atmel-st: get and use slow clock

2 files changed, 32 insertions, 11 deletions

diff --git a/drivers/clocksource/tcb_clksrc.c b/drivers/clocksource/tcb_clksrc.c
index d28d2fe798d5..6ee91401918e 100644
--- a/drivers/clocksource/tcb_clksrc.c
+++ b/drivers/clocksource/tcb_clksrc.c
@@ -193,10 +193,17 @@ static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
 	struct clk *t2_clk = tc->clk[2];
 	int irq = tc->irq[2];
 
+	ret = clk_prepare_enable(tc->slow_clk);
+	if (ret)
+		return ret;
+
 	/* try to enable t2 clk to avoid future errors in mode change */
 	ret = clk_prepare_enable(t2_clk);
-	if (ret)
+	if (ret) {
+		clk_disable_unprepare(tc->slow_clk);
 		return ret;
+	}
+
 	clk_disable(t2_clk);
 
 	clkevt.regs = tc->regs;
@@ -208,7 +215,8 @@ static int __init setup_clkevents(struct atmel_tc *tc, int clk32k_divisor_idx)
 
 	ret = request_irq(irq, ch2_irq, IRQF_TIMER, "tc_clkevt", &clkevt);
 	if (ret) {
-		clk_disable_unprepare(t2_clk);
+		clk_unprepare(t2_clk);
+		clk_disable_unprepare(tc->slow_clk);
 		return ret;
 	}
 
diff --git a/drivers/clocksource/timer-atmel-st.c b/drivers/clocksource/timer-atmel-st.c
index 41b7b6dc1d0d..29d21d68df5a 100644
--- a/drivers/clocksource/timer-atmel-st.c
+++ b/drivers/clocksource/timer-atmel-st.c
@@ -22,6 +22,7 @@
 #include <linux/kernel.h>
 #include <linux/interrupt.h>
 #include <linux/irq.h>
+#include <linux/clk.h>
 #include <linux/clockchips.h>
 #include <linux/export.h>
 #include <linux/mfd/syscon.h>
@@ -33,9 +34,7 @@ static unsigned long last_crtr;
 static u32 irqmask;
 static struct clock_event_device clkevt;
 static struct regmap *regmap_st;
-
-#define AT91_SLOW_CLOCK		32768
-#define RM9200_TIMER_LATCH	((AT91_SLOW_CLOCK + HZ/2) / HZ)
+static int timer_latch;
 
 /*
  * The ST_CRTR is updated asynchronously to the master clock ... but
@@ -82,8 +81,8 @@ static irqreturn_t at91rm9200_timer_interrupt(int irq, void *dev_id)
 	if (sr & AT91_ST_PITS) {
 		u32	crtr = read_CRTR();
 
-		while (((crtr - last_crtr) & AT91_ST_CRTV) >= RM9200_TIMER_LATCH) {
-			last_crtr += RM9200_TIMER_LATCH;
+		while (((crtr - last_crtr) & AT91_ST_CRTV) >= timer_latch) {
+			last_crtr += timer_latch;
 			clkevt.event_handler(&clkevt);
 		}
 		return IRQ_HANDLED;
@@ -144,7 +143,7 @@ static int clkevt32k_set_periodic(struct clock_event_device *dev)
 
 	/* PIT for periodic irqs; fixed rate of 1/HZ */
 	irqmask = AT91_ST_PITS;
-	regmap_write(regmap_st, AT91_ST_PIMR, RM9200_TIMER_LATCH);
+	regmap_write(regmap_st, AT91_ST_PIMR, timer_latch);
 	regmap_write(regmap_st, AT91_ST_IER, irqmask);
 	return 0;
 }
@@ -197,7 +196,8 @@ static struct clock_event_device clkevt = {
  */
 static void __init atmel_st_timer_init(struct device_node *node)
 {
-	unsigned int val;
+	struct clk *sclk;
+	unsigned int sclk_rate, val;
 	int irq, ret;
 
 	regmap_st = syscon_node_to_regmap(node);
@@ -221,6 +221,19 @@ static void __init atmel_st_timer_init(struct device_node *node)
 	if (ret)
 		panic(pr_fmt("Unable to setup IRQ\n"));
 
+	sclk = of_clk_get(node, 0);
+	if (IS_ERR(sclk))
+		panic(pr_fmt("Unable to get slow clock\n"));
+
+	clk_prepare_enable(sclk);
+	if (ret)
+		panic(pr_fmt("Could not enable slow clock\n"));
+
+	sclk_rate = clk_get_rate(sclk);
+	if (!sclk_rate)
+		panic(pr_fmt("Invalid slow clock rate\n"));
+	timer_latch = (sclk_rate + HZ / 2) / HZ;
+
 	/* The 32KiHz "Slow Clock" (tick every 30517.58 nanoseconds) is used
 	 * directly for the clocksource and all clockevents, after adjusting
 	 * its prescaler from the 1 Hz default.
@@ -229,11 +242,11 @@ static void __init atmel_st_timer_init(struct device_node *node)
 
 	/* Setup timer clockevent, with minimum of two ticks (important!!) */
 	clkevt.cpumask = cpumask_of(0);
-	clockevents_config_and_register(&clkevt, AT91_SLOW_CLOCK,
+	clockevents_config_and_register(&clkevt, sclk_rate,
 					2, AT91_ST_ALMV);
 
 	/* register clocksource */
-	clocksource_register_hz(&clk32k, AT91_SLOW_CLOCK);
+	clocksource_register_hz(&clk32k, sclk_rate);
 }
 CLOCKSOURCE_OF_DECLARE(atmel_st_timer, "atmel,at91rm9200-st",
 		       atmel_st_timer_init);