Adding timer_init function to create and initialize the timer
device on platforms where u-boot,dm-pre-reloc is not used. Since
there will be multiple timer devices in the system, adding a
tick-timer node in chosen node to know which timer device to be
used as tick timer in u-boot.
Signed-off-by: Mugunthan V N <mugunthan...@ti.com>
---
doc/device-tree-bindings/chosen.txt | 43 +++++++++++++++++++++++++++++++++++++
drivers/timer/timer-uclass.c | 34 +++++++++++++++++++++++++++++
lib/time.c | 5 +++++
3 files changed, 82 insertions(+)
create mode 100644 doc/device-tree-bindings/chosen.txt
diff --git a/doc/device-tree-bindings/chosen.txt
b/doc/device-tree-bindings/chosen.txt
new file mode 100644
index 0000000..58f29f9
--- /dev/null
+++ b/doc/device-tree-bindings/chosen.txt
@@ -0,0 +1,43 @@
+The chosen node
+---------------
+The chosen node does not represent a real device, but serves as a place
+for passing data like which serial device to used to print the logs etc
+
+
+stdout-path property
+--------------------
+Device trees may specify the device to be used for boot console output
+with a stdout-path property under /chosen.
+
+Example
+-------
+/ {
+ chosen {
+ stdout-path = "/serial@f00:115200";
+ };
+
+ serial@f00 {
+ compatible = "vendor,some-uart";
+ reg = <0xf00 0x10>;
+ };
+};
+
+tick-timer property
+-------------------
+In a system there are multiple timers, specify which timer to be used
+as the tick-timer. Earlier it was hardcoded in the timer driver now
+since device tree has all the timer nodes. Specify which timer to be
+used as tick timer.
+
+Example
+-------
+/ {
+ chosen {
+ tick-timer = &timer2;
+ };
+
+ timer2@f00 {
+ compatible = "vendor,some-uart";
+ reg = <0xf00 0x10>;
+ };
+};
diff --git a/drivers/timer/timer-uclass.c b/drivers/timer/timer-uclass.c
index 12aee5b..78ec989 100644
--- a/drivers/timer/timer-uclass.c
+++ b/drivers/timer/timer-uclass.c
@@ -6,9 +6,13 @@
#include <common.h>
#include <dm.h>
+#include <dm/lists.h>
+#include <dm/device-internal.h>
#include <errno.h>
#include <timer.h>
+DECLARE_GLOBAL_DATA_PTR;
+
/*
* Implement a Timer uclass to work with lib/time.c. The timer is usually
* a 32 bits free-running up counter. The get_rate() method is used to get
@@ -35,6 +39,36 @@ unsigned long timer_get_rate(struct udevice *dev)
return uc_priv->clock_rate;
}
+int timer_init(void)
+{
+ const void *blob = gd->fdt_blob;
+ struct udevice *dev;
+ int node;
+
+ if (CONFIG_IS_ENABLED(OF_CONTROL) && blob) {
+ /* Check for a chosen timer to be used for tick */
+ node = fdtdec_get_chosen_node(blob, "tick-timer");
+ if (node < 0)
+ return -ENODEV;
+
+ if (uclass_get_device_by_of_offset(UCLASS_TIMER, node, &dev)) {
+ /*
+ * If the timer is not marked to be bound before
+ * relocation, bind it anyway.
+ */
+ if (node > 0 &&
+ !lists_bind_fdt(gd->dm_root, blob, node, &dev)) {
+ int ret = device_probe(dev);
+ if (ret)
+ return ret;
+ }
+ }
+ }
+
+ gd->timer = dev;
+ return 0;
+}
+
UCLASS_DRIVER(timer) = {
.id = UCLASS_TIMER,
.name = "timer",
diff --git a/lib/time.c b/lib/time.c
index b001745..22f7d23 100644
--- a/lib/time.c
+++ b/lib/time.c
@@ -47,6 +47,11 @@ static int notrace dm_timer_init(void)
int ret;
if (!gd->timer) {
+ /* Check if we have a chosen timer */
+ timer_init();
+ if (gd->timer)
+ return 0;
+
ret = uclass_first_device(UCLASS_TIMER, &dev);
if (ret)
return ret;
--
2.6.3.368.gf34be46
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