dw_apb_timer_of.c: remove parts that were picoxcell-specific

Pavel Machek
2013-04-26T12:14:38Z

It seems we made a mistake when creating dw_apb_timer_of.c:
picoxcell sched_clock parts were not related to dw_apb_timer, yet
we moved them to dw_apb_timer_of, and tried to use them on socfpga.

This results in system where user/system time is not measured properly,
as demonstrated by

time dd if=/dev/urandom of=/dev/zero bs=100000 count=100

.

So this patch:

1) moves picoxcell sched_clock parts back to picoxcell

2) adds support to use dw_apb_timer s as sched_clock. Picoxcell could
consider switching to these

3) adds missing of_node_put() in dw_apb_timer_init().

Tested on socfpga, soc-next (3.9-rc6) based tree.

Signed-off-by: Pavel Machek <pavel@denx.de>
Tested-by: Dinh Nguyen <dinguyen@altera.com>

---

I think this is ready to go to soc-next tree. Please apply,
Pavel

diff --git a/arch/arm/mach-picoxcell/common.c b/arch/arm/mach-picoxcell/common.c
index 70b441a..22759f5 100644
--- a/arch/arm/mach-picoxcell/common.c
+++ b/arch/arm/mach-picoxcell/common.c
@@ -84,11 +84,39 @@ static void picoxcell_wdt_restart(char mode, const char *cmd)
}
}

+static const struct of_device_id picochip_rtc_ids[] __initconst = {
+ { .compatible = "picochip,pc3x2-rtc" },
+ { /* Sentinel */ },
+};
+
+static void __iomem *sched_io_base;
+
+static u32 read_sched_clock(void)
+{
+ return __raw_readl(sched_io_base);
+}
+
+static void __init timer_init(void)
+{
+ u32 rate;
+
+ dw_apb_timer_init(0);
+
+ sched_timer = of_find_matching_node(timer, osctimer_ids);
+ if (!sched_timer)
+ panic("No suitable timer for scheduler clock\n");
+
+ timer_get_base_and_rate(sched_timer, &sched_io_base, &rate);
+ of_node_put(sched_timer);
+
+ setup_sched_clock(read_sched_clock, 32, rate);
+}
+
DT_MACHINE_START(PICOXCELL, "Picochip picoXcell")
.map_io = picoxcell_map_io,
.nr_irqs = NR_IRQS_LEGACY,
.init_irq = irqchip_init,
- .init_time = dw_apb_timer_init,
+ .init_time = timer_init,
.init_machine = picoxcell_init_machine,
.dt_compat = picoxcell_dt_match,
.restart = picoxcell_wdt_restart,
diff --git a/arch/arm/mach-socfpga/socfpga.c b/arch/arm/mach-socfpga/socfpga.c
index 46a0513..3a030e5 100644
--- a/arch/arm/mach-socfpga/socfpga.c
+++ b/arch/arm/mach-socfpga/socfpga.c
@@ -116,11 +116,17 @@ static const char *altera_dt_match[] = {
NULL
};

+static void __init timer_init(void)
+{
+ dw_apb_timer_init(1);
+}
+
+
DT_MACHINE_START(SOCFPGA, "Altera SOCFPGA")
.smp = smp_ops(socfpga_smp_ops),
.map_io = socfpga_map_io,
.init_irq = socfpga_init_irq,
- .init_time = dw_apb_timer_init,
+ .init_time = timer_init,
.init_machine = socfpga_cyclone5_init,
.restart = socfpga_cyclone5_restart,
.dt_compat = altera_dt_match,
diff --git a/drivers/clocksource/dw_apb_timer.c b/drivers/clocksource/dw_apb_timer.c
index 8c2a35f..460ac99 100644
--- a/drivers/clocksource/dw_apb_timer.c
+++ b/drivers/clocksource/dw_apb_timer.c
@@ -21,12 +21,6 @@
#define APBT_MIN_PERIOD 4
#define APBT_MIN_DELTA_USEC 200

-#define APBTMR_N_LOAD_COUNT 0x00
-#define APBTMR_N_CURRENT_VALUE 0x04
-#define APBTMR_N_CONTROL 0x08
-#define APBTMR_N_EOI 0x0c
-#define APBTMR_N_INT_STATUS 0x10
-
#define APBTMRS_INT_STATUS 0xa0
#define APBTMRS_EOI 0xa4
#define APBTMRS_RAW_INT_STATUS 0xa8
diff --git a/drivers/clocksource/dw_apb_timer_of.c b/drivers/clocksource/dw_apb_timer_of.c
index ab09ed3..ac4ea00 100644
--- a/drivers/clocksource/dw_apb_timer_of.c
+++ b/drivers/clocksource/dw_apb_timer_of.c
@@ -57,7 +57,16 @@ static void add_clockevent(struct device_node *event_timer)
dw_apb_clockevent_register(ced);
}

-static void add_clocksource(struct device_node *source_timer)
+static void __iomem *sched_io_base;
+
+/* This is actually same as __apbt_read_clocksource(), but with
+ different interface */
+static u32 read_sched_clock_sptimer(void)
+{
+ return ~__raw_readl(sched_io_base + APBTMR_N_CURRENT_VALUE);
+}
+
+static void add_clocksource(struct device_node *source_timer, int use_as_scheduler)
{
void __iomem *iobase;
struct dw_apb_clocksource *cs;
@@ -71,45 +80,33 @@ static void add_clocksource(struct device_node *source_timer)

dw_apb_clocksource_start(cs);
dw_apb_clocksource_register(cs);
-}

-static void __iomem *sched_io_base;
-
-static u32 read_sched_clock(void)
-{
- return __raw_readl(sched_io_base);
+ if (use_as_scheduler) {
+ sched_io_base = iobase;
+ setup_sched_clock(read_sched_clock_sptimer, 32, rate);
+ }
}

-static const struct of_device_id sptimer_ids[] __initconst = {
- { .compatible = "picochip,pc3x2-rtc" },
+static const struct of_device_id osctimer_ids[] __initconst = {
+ { .compatible = "picochip,pc3x2-timer" },
+ { .compatible = "snps,dw-apb-timer-osc" },
{ .compatible = "snps,dw-apb-timer-sp" },
- { /* Sentinel */ },
+ { /* Sentinel */ },
};

-static void init_sched_clock(void)
-{
- struct device_node *sched_timer;
- u32 rate;
-
- sched_timer = of_find_matching_node(NULL, sptimer_ids);
- if (!sched_timer)
- panic("No RTC for sched clock to use");
-
- timer_get_base_and_rate(sched_timer, &sched_io_base, &rate);
- of_node_put(sched_timer);
+/*
+ You don't have to use dw_apb_timer for scheduler clock,
+ this should also work fine on arm:

- setup_sched_clock(read_sched_clock, 32, rate);
-}
+ twd_local_timer_of_register();
+ arch_timer_of_register();
+ arch_timer_sched_clock_init();
+*/

-static const struct of_device_id osctimer_ids[] __initconst = {
- { .compatible = "picochip,pc3x2-timer" },
- { .compatible = "snps,dw-apb-timer-osc" },
- {},
-};

-void __init dw_apb_timer_init(void)
+void __init dw_apb_timer_init(int use_as_scheduler)
{
struct device_node *event_timer, *source_timer;

event_timer = of_find_matching_node(NULL, osctimer_ids);
if (!event_timer)
@@ -119,9 +117,8 @@ void __init dw_apb_timer_init(void)
source_timer = of_find_matching_node(event_timer, osctimer_ids);
if (!source_timer)
panic("No timer for clocksource");
- add_clocksource(source_timer);
+ add_clocksource(source_timer, use_as_scheduler);

+ of_node_put(event_timer);
of_node_put(source_timer);
-
- init_sched_clock();
}
diff --git a/include/linux/dw_apb_timer.h b/include/linux/dw_apb_timer.h
index dd755ce..d503245 100644
--- a/include/linux/dw_apb_timer.h
+++ b/include/linux/dw_apb_timer.h
@@ -17,6 +17,12 @@
#include <linux/clocksource.h>
#include <linux/interrupt.h>

+#define APBTMR_N_LOAD_COUNT 0x00
+#define APBTMR_N_CURRENT_VALUE 0x04
+#define APBTMR_N_CONTROL 0x08
+#define APBTMR_N_EOI 0x0c
+#define APBTMR_N_INT_STATUS 0x10
+
#define APBTMRS_REG_SIZE 0x14

struct dw_apb_timer {
@@ -53,5 +59,5 @@ void dw_apb_clocksource_start(struct dw_apb_clocksource *dw_cs);
cycle_t dw_apb_clocksource_read(struct dw_apb_clocksource *dw_cs);
void dw_apb_clocksource_unregister(struct dw_apb_clocksource *dw_cs);

-extern void dw_apb_timer_init(void);
+extern void dw_apb_timer_init(int);
#endif /* __DW_APB_TIMER_H__ */