dm: timer: uclass: add timer init in uclass driver to add timer device

Adding timer init function in timer-uclass driver 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 <mugunthanvnm@ti.com>
This commit is contained in:
Mugunthan V N 2016-01-16 21:33:58 +05:30 committed by Simon Glass
parent 28a6c01187
commit c833697538
4 changed files with 96 additions and 17 deletions

View file

@ -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@f00";
};
timer2@f00 {
compatible = "vendor,some-timer";
reg = <0xf00 0x10>;
};
};

View file

@ -6,6 +6,8 @@
#include <common.h>
#include <dm.h>
#include <dm/lists.h>
#include <dm/device-internal.h>
#include <errno.h>
#include <timer.h>
@ -56,6 +58,48 @@ u64 timer_conv_64(u32 count)
return ((u64)gd->timebase_h << 32) | gd->timebase_l;
}
int notrace dm_timer_init(void)
{
const void *blob = gd->fdt_blob;
struct udevice *dev = NULL;
int node;
int ret;
if (gd->timer)
return 0;
/* Check for a chosen timer to be used for tick */
node = fdtdec_get_chosen_node(blob, "tick-timer");
if (node < 0) {
/* No chosen timer, trying first available timer */
ret = uclass_first_device(UCLASS_TIMER, &dev);
if (ret)
return ret;
if (!dev)
return -ENODEV;
} else {
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)) {
ret = device_probe(dev);
if (ret)
return ret;
}
}
}
if (dev) {
gd->timer = dev;
return 0;
}
return -ENODEV;
}
UCLASS_DRIVER(timer) = {
.id = UCLASS_TIMER,
.name = "timer",

View file

@ -7,6 +7,15 @@
#ifndef _TIMER_H_
#define _TIMER_H_
/*
* dm_timer_init - initialize a timer for time keeping. On success
* initializes gd->timer so that lib/timer can use it for future
* referrence.
*
* @return - 0 on success or error number
*/
int dm_timer_init(void);
/*
* timer_conv_64 - convert 32-bit counter value to 64-bit
*

View file

@ -41,23 +41,6 @@ extern unsigned long __weak timer_read_counter(void);
#endif
#ifdef CONFIG_TIMER
static int notrace dm_timer_init(void)
{
struct udevice *dev;
int ret;
if (!gd->timer) {
ret = uclass_first_device(UCLASS_TIMER, &dev);
if (ret)
return ret;
if (!dev)
return -ENODEV;
gd->timer = dev;
}
return 0;
}
ulong notrace get_tbclk(void)
{
int ret;