For OMAP devices, the 32kHz counter is the default clock-source for the kernel.
However, this is not the only possible clock-source the kernel can use for OMAP
devices.
When booting with device-tree, if the 32kHz counter is the desired clock-source
for the kernel, then parse the device-tree blob to ensure that the counter is
present and if so map memory for the counter using the device-tree of_iomap()
function so we are no longer reliant on the OMAP HWMOD framework to do this for
us.
Signed-off-by: Jon Hunter <jon-hunter@xxxxxx>
---
arch/arm/mach-omap2/timer.c | 28 +++++++++++++++++++++++++++-
1 file changed, 27 insertions(+), 1 deletion(-)
diff --git a/arch/arm/mach-omap2/timer.c b/arch/arm/mach-omap2/timer.c
index d064afd..a67688f 100644
--- a/arch/arm/mach-omap2/timer.c
+++ b/arch/arm/mach-omap2/timer.c
@@ -159,6 +159,11 @@ static struct of_device_id omap_timer_match[] __initdata = {
{ }
};
+static struct of_device_id omap_counter_match[] __initdata = {
+ { .compatible = "ti,omap-counter32k", },
+ { }
+};
+
/**
* omap_get_timer_dt - get a timer using device-tree
* @match - device-tree match structure for matching a device type
@@ -378,11 +383,26 @@ static u32 notrace dmtimer_read_sched_clock(void)
static int __init omap2_sync32k_clocksource_init(void)
{
int ret;
+ struct device_node *np = NULL;
struct omap_hwmod *oh;
void __iomem *vbase;
const char *oh_name = "counter_32k";
/*
+ * If device-tree is present, then search the DT blob
+ * to see if the 32kHz counter is supported.
+ */
+ if (of_have_populated_dt()) {
+ np = omap_get_timer_dt(omap_counter_match, NULL);
+ if (!np)
+ return -ENODEV;
+
+ of_property_read_string_index(np, "ti,hwmods", 0, &oh_name);
+ if (!oh_name)
+ return -ENODEV;
+ }
+
+ /*
* First check hwmod data is available for sync32k counter
*/
oh = omap_hwmod_lookup(oh_name);
@@ -391,7 +411,13 @@ static int __init omap2_sync32k_clocksource_init(void)
omap_hwmod_setup_one(oh_name);
- vbase = omap_hwmod_get_mpu_rt_va(oh);
+ if (of_have_populated_dt()) {
+ vbase = of_iomap(np, 0);
+ of_node_put(np);
+ } else {
+ vbase = omap_hwmod_get_mpu_rt_va(oh);
+ }
+
if (!vbase) {
pr_warn("%s: failed to get counter_32k resource\n", __func__);
return -ENXIO;
--
1.7.9.5
--
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