Re: [PATCH v2 01/18] clocksource: sp804: Add support for non-32bit width counter
From: Daniel Lezcano
Date: Thu Mar 17 2016 - 12:40:28 EST
On 03/09/2016 11:24 AM, Neil Armstrong wrote:
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@xxxxxxxxxxxx>
---
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;
+
check comment below in the caller function.
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;
Check comment below in the caller function.
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));
This GENMASK is strange here. Nothing else than this ?
}
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);
+
Better to do the sanity check when the value is read.
Here, you can default to 32 if the width is 0 instead of initializing to
32 then read the property and call __sp804_clockevents_init which in
turn check zero or more and set it to 32 again.
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
--
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