Commit d8e03643 authored by Marc Zyngier's avatar Marc Zyngier

ARM: smp_twd: add device tree support

Add bindings to support DT discovery of the ARM Timer Watchdog
(aka TWD). Only the timer side is converted by this patch.
Acked-by: default avatarRob Herring <rob.herring@calxeda.com>
Signed-off-by: default avatarMarc Zyngier <marc.zyngier@arm.com>
parent 81e46f7b
* ARM Timer Watchdog
ARM 11MP, Cortex-A5 and Cortex-A9 are often associated with a per-core
Timer-Watchdog (aka TWD), which provides both a per-cpu local timer
and watchdog.
The TWD is usually attached to a GIC to deliver its two per-processor
interrupts.
** Timer node required properties:
- compatible : Should be one of:
"arm,cortex-a9-twd-timer"
"arm,cortex-a5-twd-timer"
"arm,arm11mp-twd-timer"
- interrupts : One interrupt to each core
- reg : Specify the base address and the size of the TWD timer
register window.
Example:
twd-timer@2c000600 {
compatible = "arm,arm11mp-twd-timer"";
reg = <0x2c000600 0x20>;
interrupts = <1 13 0xf01>;
};
** Watchdog node properties:
- compatible : Should be one of:
"arm,cortex-a9-twd-wdt"
"arm,cortex-a5-twd-wdt"
"arm,arm11mp-twd-wdt"
- interrupts : One interrupt to each core
- reg : Specify the base address and the size of the TWD watchdog
register window.
Example:
twd-watchdog@2c000620 {
compatible = "arm,arm11mp-twd-wdt";
reg = <0x2c000620 0x20>;
interrupts = <1 14 0xf01>;
};
......@@ -40,4 +40,12 @@ struct twd_local_timer name __initdata = { \
int twd_local_timer_register(struct twd_local_timer *);
#ifdef CONFIG_HAVE_ARM_TWD
void twd_local_timer_of_register(void);
#else
static inline void twd_local_timer_of_register(void)
{
}
#endif
#endif
......@@ -20,6 +20,8 @@
#include <linux/clockchips.h>
#include <linux/irq.h>
#include <linux/io.h>
#include <linux/of_irq.h>
#include <linux/of_address.h>
#include <asm/smp_twd.h>
#include <asm/localtimer.h>
......@@ -284,37 +286,86 @@ static struct local_timer_ops twd_lt_ops __cpuinitdata = {
.stop = twd_timer_stop,
};
int __init twd_local_timer_register(struct twd_local_timer *tlt)
static int __init twd_local_timer_common_register(void)
{
int err;
if (twd_base || twd_evt)
return -EBUSY;
twd_ppi = tlt->res[1].start;
twd_evt = alloc_percpu(struct clock_event_device *);
twd_base = ioremap(tlt->res[0].start, resource_size(&tlt->res[0]));
if (!twd_base || !twd_evt) {
if (!twd_evt) {
err = -ENOMEM;
goto out;
goto out_free;
}
err = request_percpu_irq(twd_ppi, twd_handler, "twd", twd_evt);
if (err) {
pr_err("twd: can't register interrupt %d (%d)\n", twd_ppi, err);
goto out;
goto out_free;
}
err = local_timer_register(&twd_lt_ops);
if (err)
goto out;
goto out_irq;
return 0;
out:
out_irq:
free_percpu_irq(twd_ppi, twd_evt);
out_free:
iounmap(twd_base);
twd_base = NULL;
free_percpu(twd_evt);
twd_base = twd_evt = NULL;
return err;
}
int __init twd_local_timer_register(struct twd_local_timer *tlt)
{
if (twd_base || twd_evt)
return -EBUSY;
twd_ppi = tlt->res[1].start;
twd_base = ioremap(tlt->res[0].start, resource_size(&tlt->res[0]));
if (!twd_base)
return -ENOMEM;
return twd_local_timer_common_register();
}
#ifdef CONFIG_OF
const static struct of_device_id twd_of_match[] __initconst = {
{ .compatible = "arm,cortex-a9-twd-timer", },
{ .compatible = "arm,cortex-a5-twd-timer", },
{ .compatible = "arm,arm11mp-twd-timer", },
{ },
};
void __init twd_local_timer_of_register(void)
{
struct device_node *np;
int err;
np = of_find_matching_node(NULL, twd_of_match);
if (!np) {
err = -ENODEV;
goto out;
}
twd_ppi = irq_of_parse_and_map(np, 0);
if (!twd_ppi) {
err = -EINVAL;
goto out;
}
twd_base = of_iomap(np, 0);
if (!twd_base) {
err = -ENOMEM;
goto out;
}
err = twd_local_timer_common_register();
out:
WARN(err, "twd_local_timer_of_register failed (%d)\n", err);
}
#endif
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