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authorOlof Johansson <olof@lixom.net>2012-05-10 23:46:06 -0700
committerOlof Johansson <olof@lixom.net>2012-05-10 23:46:06 -0700
commit030caf3f22395d564ee8a4f056a9cb7190a7eed4 (patch)
treee421b64e36c35013fc6a15e006438ae67573403b /arch/arm/mach-omap2
parente2e9bbeec90cb5a23cef153b54ec4307255f4e09 (diff)
parent1fe97c8f6a1de67a5f56e029a818903d5bed8017 (diff)
downloadblackbird-op-linux-030caf3f22395d564ee8a4f056a9cb7190a7eed4.tar.gz
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Merge tag 'omap-cleanup-timer-for-v3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap into next/cleanup2
Timer changes to make it easier to support various SoCs By Vaibhav Hiremath via Tony Lindgren * tag 'omap-cleanup-timer-for-v3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/tmlind/linux-omap: ARM: OMAP: Make OMAP clocksource source selection using kernel param ARM: OMAP2+: Replace space with underscore in the name field of system timers ARM: OMAP1: Add checks for possible error condition in timer_init
Diffstat (limited to 'arch/arm/mach-omap2')
-rw-r--r--arch/arm/mach-omap2/timer.c118
1 files changed, 93 insertions, 25 deletions
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index 1b7835865c83..840929bd9dae 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -90,7 +90,7 @@ static irqreturn_t omap2_gp_timer_interrupt(int irq, void *dev_id)
}
static struct irqaction omap2_gp_timer_irq = {
- .name = "gp timer",
+ .name = "gp_timer",
.flags = IRQF_DISABLED | IRQF_TIMER | IRQF_IRQPOLL,
.handler = omap2_gp_timer_interrupt,
};
@@ -132,7 +132,7 @@ static void omap2_gp_timer_set_mode(enum clock_event_mode mode,
}
static struct clock_event_device clockevent_gpt = {
- .name = "gp timer",
+ .name = "gp_timer",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.shift = 32,
.set_next_event = omap2_gp_timer_set_next_event,
@@ -236,22 +236,8 @@ static void __init omap2_gp_clockevent_init(int gptimer_id,
}
/* Clocksource code */
-
-#ifdef CONFIG_OMAP_32K_TIMER
-/*
- * When 32k-timer is enabled, don't use GPTimer for clocksource
- * instead, just leave default clocksource which uses the 32k
- * sync counter. See clocksource setup in plat-omap/counter_32k.c
- */
-
-static void __init omap2_gp_clocksource_init(int unused, const char *dummy)
-{
- omap_init_clocksource_32k();
-}
-
-#else
-
static struct omap_dm_timer clksrc;
+static bool use_gptimer_clksrc;
/*
* clocksource
@@ -262,7 +248,7 @@ static cycle_t clocksource_read_cycles(struct clocksource *cs)
}
static struct clocksource clocksource_gpt = {
- .name = "gp timer",
+ .name = "gp_timer",
.rating = 300,
.read = clocksource_read_cycles,
.mask = CLOCKSOURCE_MASK(32),
@@ -278,7 +264,46 @@ static u32 notrace dmtimer_read_sched_clock(void)
}
/* Setup free-running counter for clocksource */
-static void __init omap2_gp_clocksource_init(int gptimer_id,
+static int __init omap2_sync32k_clocksource_init(void)
+{
+ int ret;
+ struct omap_hwmod *oh;
+ void __iomem *vbase;
+ const char *oh_name = "counter_32k";
+
+ /*
+ * First check hwmod data is available for sync32k counter
+ */
+ oh = omap_hwmod_lookup(oh_name);
+ if (!oh || oh->slaves_cnt == 0)
+ return -ENODEV;
+
+ omap_hwmod_setup_one(oh_name);
+
+ vbase = omap_hwmod_get_mpu_rt_va(oh);
+ if (!vbase) {
+ pr_warn("%s: failed to get counter_32k resource\n", __func__);
+ return -ENXIO;
+ }
+
+ ret = omap_hwmod_enable(oh);
+ if (ret) {
+ pr_warn("%s: failed to enable counter_32k module (%d)\n",
+ __func__, ret);
+ return ret;
+ }
+
+ ret = omap_init_clocksource_32k(vbase);
+ if (ret) {
+ pr_warn("%s: failed to initialize counter_32k as a clocksource (%d)\n",
+ __func__, ret);
+ omap_hwmod_idle(oh);
+ }
+
+ return ret;
+}
+
+static void __init omap2_gptimer_clocksource_init(int gptimer_id,
const char *fck_source)
{
int res;
@@ -286,9 +311,6 @@ static void __init omap2_gp_clocksource_init(int gptimer_id,
res = omap_dm_timer_init_one(&clksrc, gptimer_id, fck_source);
BUG_ON(res);
- pr_info("OMAP clocksource: GPTIMER%d at %lu Hz\n",
- gptimer_id, clksrc.rate);
-
__omap_dm_timer_load_start(&clksrc,
OMAP_TIMER_CTRL_ST | OMAP_TIMER_CTRL_AR, 0, 1);
setup_sched_clock(dmtimer_read_sched_clock, 32, clksrc.rate);
@@ -296,15 +318,36 @@ static void __init omap2_gp_clocksource_init(int gptimer_id,
if (clocksource_register_hz(&clocksource_gpt, clksrc.rate))
pr_err("Could not register clocksource %s\n",
clocksource_gpt.name);
+ else
+ pr_info("OMAP clocksource: GPTIMER%d at %lu Hz\n",
+ gptimer_id, clksrc.rate);
+}
+
+static void __init omap2_clocksource_init(int gptimer_id,
+ const char *fck_source)
+{
+ /*
+ * First give preference to kernel parameter configuration
+ * by user (clocksource="gp_timer").
+ *
+ * In case of missing kernel parameter for clocksource,
+ * first check for availability for 32k-sync timer, in case
+ * of failure in finding 32k_counter module or registering
+ * it as clocksource, execution will fallback to gp-timer.
+ */
+ if (use_gptimer_clksrc == true)
+ omap2_gptimer_clocksource_init(gptimer_id, fck_source);
+ else if (omap2_sync32k_clocksource_init())
+ /* Fall back to gp-timer code */
+ omap2_gptimer_clocksource_init(gptimer_id, fck_source);
}
-#endif
#define OMAP_SYS_TIMER_INIT(name, clkev_nr, clkev_src, \
clksrc_nr, clksrc_src) \
static void __init omap##name##_timer_init(void) \
{ \
omap2_gp_clockevent_init((clkev_nr), clkev_src); \
- omap2_gp_clocksource_init((clksrc_nr), clksrc_src); \
+ omap2_clocksource_init((clksrc_nr), clksrc_src); \
}
#define OMAP_SYS_TIMER(name) \
@@ -335,7 +378,7 @@ static DEFINE_TWD_LOCAL_TIMER(twd_local_timer,
static void __init omap4_timer_init(void)
{
omap2_gp_clockevent_init(1, OMAP4_CLKEV_SOURCE);
- omap2_gp_clocksource_init(2, OMAP4_MPU_SOURCE);
+ omap2_clocksource_init(2, OMAP4_MPU_SOURCE);
#ifdef CONFIG_LOCAL_TIMERS
/* Local timers are not supprted on OMAP4430 ES1.0 */
if (omap_rev() != OMAP4430_REV_ES1_0) {
@@ -503,3 +546,28 @@ static int __init omap2_dm_timer_init(void)
return 0;
}
arch_initcall(omap2_dm_timer_init);
+
+/**
+ * omap2_override_clocksource - clocksource override with user configuration
+ *
+ * Allows user to override default clocksource, using kernel parameter
+ * clocksource="gp_timer" (For all OMAP2PLUS architectures)
+ *
+ * Note that, here we are using same standard kernel parameter "clocksource=",
+ * and not introducing any OMAP specific interface.
+ */
+static int __init omap2_override_clocksource(char *str)
+{
+ if (!str)
+ return 0;
+ /*
+ * For OMAP architecture, we only have two options
+ * - sync_32k (default)
+ * - gp_timer (sys_clk based)
+ */
+ if (!strcmp(str, "gp_timer"))
+ use_gptimer_clksrc = true;
+
+ return 0;
+}
+early_param("clocksource", omap2_override_clocksource);
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