[PATCH 2/2] clocksource: cadence_ttc: Add support for 32bit mode

From: Michal Simek
Date: Wed Sep 17 2014 - 10:31:07 EST


New TTCs support 32bit mode. Older versions support
only 16bit modes. Keep 16bit mode as default
and 32bit optional.

Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
---

drivers/clocksource/cadence_ttc_timer.c | 15 ++++++++++-----
1 file changed, 10 insertions(+), 5 deletions(-)

diff --git a/drivers/clocksource/cadence_ttc_timer.c b/drivers/clocksource/cadence_ttc_timer.c
index 7a08811df9aa..510c8a1d37b3 100644
--- a/drivers/clocksource/cadence_ttc_timer.c
+++ b/drivers/clocksource/cadence_ttc_timer.c
@@ -25,7 +25,7 @@
#include <linux/sched_clock.h>

/*
- * This driver configures the 2 16-bit count-up timers as follows:
+ * This driver configures the 2 16/32-bit count-up timers as follows:
*
* T1: Timer 1, clocksource for generic timekeeping
* T2: Timer 2, clockevent source for hrtimers
@@ -321,7 +321,8 @@ static int ttc_rate_change_clocksource_cb(struct notifier_block *nb,
return NOTIFY_DONE;
}

-static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base)
+static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base,
+ u32 timer_width)
{
struct ttc_timer_clocksource *ttccs;
int err;
@@ -351,7 +352,7 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base)
ttccs->cs.name = "ttc_clocksource";
ttccs->cs.rating = 200;
ttccs->cs.read = __ttc_clocksource_read;
- ttccs->cs.mask = CLOCKSOURCE_MASK(16);
+ ttccs->cs.mask = CLOCKSOURCE_MASK(timer_width);
ttccs->cs.flags = CLOCK_SOURCE_IS_CONTINUOUS;

/*
@@ -372,7 +373,8 @@ static void __init ttc_setup_clocksource(struct clk *clk, void __iomem *base)
}

ttc_sched_clock_val_reg = base + TTC_COUNT_VAL_OFFSET;
- sched_clock_register(ttc_sched_clock_read, 16, ttccs->ttc.freq / PRESCALE);
+ sched_clock_register(ttc_sched_clock_read, timer_width,
+ ttccs->ttc.freq / PRESCALE);
}

static int ttc_rate_change_clockevent_cb(struct notifier_block *nb,
@@ -467,6 +469,7 @@ static void __init ttc_timer_init(struct device_node *timer)
struct clk *clk_cs, *clk_ce;
static int initialized;
int clksel;
+ u32 timer_width = 16;

if (initialized)
return;
@@ -490,6 +493,8 @@ static void __init ttc_timer_init(struct device_node *timer)
BUG();
}

+ of_property_read_u32(timer, "timer-width", &timer_width);
+
clksel = readl_relaxed(timer_baseaddr + TTC_CLK_CNTRL_OFFSET);
clksel = !!(clksel & TTC_CLK_CNTRL_CSRC_MASK);
clk_cs = of_clk_get(timer, clksel);
@@ -506,7 +511,7 @@ static void __init ttc_timer_init(struct device_node *timer)
BUG();
}

- ttc_setup_clocksource(clk_cs, timer_baseaddr);
+ ttc_setup_clocksource(clk_cs, timer_baseaddr, timer_width);
ttc_setup_clockevent(clk_ce, timer_baseaddr + 4, irq);

pr_info("%s #0 at %p, irq=%d\n", timer->name, timer_baseaddr, irq);
--
1.8.2.3

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