Hi Mugunthan,
On 27 November 2015 at 00:31, Mugunthan V N <mugunthan...@ti.com> wrote:
> 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;
Please add a debug() here to help people diagnose problems.
> +
> + 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)
debug()
> + 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;
This code should move up into the timer_init() function. So the sequence is:
- look for a device with 'chosen'
- find the first device
Regards,
Simon
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