[PATCH v2 01/18] clocksource: sp804: Add support for non-32bit width counter

Neil Armstrong
2016-03-09T10:24:03Z

Some vendor variants can implement norrower counter width, add
an optional DT property changing the clocksource width and the
clockevent mask, but keeping 32bit as default for legacy interface.

Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>
---
drivers/clocksource/timer-sp804.c | 38 +++++++++++++++++++++++++++-----------
include/clocksource/timer-sp804.h | 11 ++++++-----
2 files changed, 33 insertions(+), 16 deletions(-)

diff --git a/drivers/clocksource/timer-sp804.c b/drivers/clocksource/timer-sp804.c
index 5f45b9a..8acf524 100644
--- a/drivers/clocksource/timer-sp804.c
+++ b/drivers/clocksource/timer-sp804.c
@@ -80,7 +80,8 @@ void __init sp804_timer_disable(void __iomem *base)
void __init __sp804_clocksource_and_sched_clock_init(void __iomem *base,
const char *name,
struct clk *clk,
- int use_sched_clock)
+ int use_sched_clock,
+ unsigned width)
{
long rate;

@@ -93,6 +94,9 @@ void __init __sp804_clocksource_and_sched_clock_init(void __iomem *base,
}
}

+ if (!width || width > 32)
+ width = 32;
+
rate = sp804_get_clock_rate(clk);

if (rate < 0)
@@ -106,11 +110,11 @@ void __init __sp804_clocksource_and_sched_clock_init(void __iomem *base,
base + TIMER_CTRL);

clocksource_mmio_init(base + TIMER_VALUE, name,
- rate, 200, 32, clocksource_mmio_readl_down);
+ rate, 200, width, clocksource_mmio_readl_down);

if (use_sched_clock) {
sched_clock_base = base;
- sched_clock_register(sp804_read, 32, rate);
+ sched_clock_register(sp804_read, width, rate);
}
}

@@ -186,7 +190,9 @@ static struct irqaction sp804_timer_irq = {
.dev_id = &sp804_clockevent,
};

-void __init __sp804_clockevents_init(void __iomem *base, unsigned int irq, struct clk *clk, const char *name)
+void __init __sp804_clockevents_init(void __iomem *base, unsigned int irq,
+ struct clk *clk, const char *name,
+ unsigned width)
{
struct clock_event_device *evt = &sp804_clockevent;
long rate;
@@ -199,6 +205,9 @@ void __init __sp804_clockevents_init(void __iomem *base, unsigned int irq, struc
return;
}

+ if (!width || width > 32)
+ width = 32;
+
rate = sp804_get_clock_rate(clk);
if (rate < 0)
return;
@@ -212,7 +221,7 @@ void __init __sp804_clockevents_init(void __iomem *base, unsigned int irq, struc
writel(0, base + TIMER_CTRL);

setup_irq(irq, &sp804_timer_irq);
- clockevents_config_and_register(evt, rate, 0xf, 0xffffffff);
+ clockevents_config_and_register(evt, rate, 0xf, GENMASK(width-1, 0));
}

static void __init sp804_of_init(struct device_node *np)
@@ -223,6 +232,7 @@ static void __init sp804_of_init(struct device_node *np)
u32 irq_num = 0;
struct clk *clk1, *clk2;
const char *name = of_get_property(np, "compatible", NULL);
+ u32 width = 32;

base = of_iomap(np, 0);
if (WARN_ON(!base))
@@ -254,14 +264,19 @@ static void __init sp804_of_init(struct device_node *np)
if (irq <= 0)
goto err;

+ /* Some vendor variants can have a different counter width */
+ of_property_read_u32(np, "arm,timer-width", &width);
+
of_property_read_u32(np, "arm,sp804-has-irq", &irq_num);
if (irq_num == 2) {
- __sp804_clockevents_init(base + TIMER_2_BASE, irq, clk2, name);
- __sp804_clocksource_and_sched_clock_init(base, name, clk1, 1);
+ __sp804_clockevents_init(base + TIMER_2_BASE, irq,
+ clk2, name, width);
+ __sp804_clocksource_and_sched_clock_init(base, name,
+ clk1, 1, width);
} else {
- __sp804_clockevents_init(base, irq, clk1 , name);
+ __sp804_clockevents_init(base, irq, clk1, name, width);
__sp804_clocksource_and_sched_clock_init(base + TIMER_2_BASE,
- name, clk2, 1);
+ name, clk2, 1, width);
}
initialized = true;

@@ -293,13 +308,14 @@ static void __init integrator_cp_of_init(struct device_node *np)
goto err;

if (!init_count)
- __sp804_clocksource_and_sched_clock_init(base, name, clk, 0);
+ __sp804_clocksource_and_sched_clock_init(base, name,
+ clk, 0, 32);
else {
irq = irq_of_parse_and_map(np, 0);
if (irq <= 0)
goto err;

- __sp804_clockevents_init(base, irq, clk, name);
+ __sp804_clockevents_init(base, irq, clk, name, 32);
}

init_count++;
diff --git a/include/clocksource/timer-sp804.h b/include/clocksource/timer-sp804.h
index 1f8a1ca..ad71fcb 100644
--- a/include/clocksource/timer-sp804.h
+++ b/include/clocksource/timer-sp804.h
@@ -4,25 +4,26 @@
struct clk;

void __sp804_clocksource_and_sched_clock_init(void __iomem *,
- const char *, struct clk *, int);
+ const char *, struct clk *,
+ int, unsigned);
void __sp804_clockevents_init(void __iomem *, unsigned int,
- struct clk *, const char *);
+ struct clk *, const char *, unsigned);
void sp804_timer_disable(void __iomem *);

static inline void sp804_clocksource_init(void __iomem *base, const char *name)
{
- __sp804_clocksource_and_sched_clock_init(base, name, NULL, 0);
+ __sp804_clocksource_and_sched_clock_init(base, name, NULL, 0, 32);
}

static inline void sp804_clocksource_and_sched_clock_init(void __iomem *base,
const char *name)
{
- __sp804_clocksource_and_sched_clock_init(base, name, NULL, 1);
+ __sp804_clocksource_and_sched_clock_init(base, name, NULL, 1, 32);
}

static inline void sp804_clockevents_init(void __iomem *base, unsigned int irq, const char *name)
{
- __sp804_clockevents_init(base, irq, NULL, name);
+ __sp804_clockevents_init(base, irq, NULL, name, 32);

}
#endif
--
1.9.1