[U-Boot] [PATCH v3 02/19] dm: timer: uclass: add timer init to add timer device

[Simon Glass]

On 25 December 2015 at 06:08, Mugunthan V N <mugunthanvnm at ti.com> wrote:
> On Friday 25 December 2015 05:43 PM, Bin Meng wrote:
>> Hi Mugunthan,
>>
>> On Fri, Dec 25, 2015 at 6:41 PM, Mugunthan V N <mugunthanvnm at 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 <mugunthanvnm at ti.com>
>>> ---
>>>
>>> Submitting 02/19 only for v3 as there is no change on other
>>> patches and to reduce traffic.
>>>
>>> This patch is verified on AM437x SK and DRA74 EVM logs [1] and
>>> pushed a branch for testing
>>>
>>> [1] - http://pastebin.ubuntu.com/14205433/
>>> [2] - git://git.ti.com/~mugunthanvnm/ti-u-boot/mugunth-ti-u-boot.git dm-timer-v3
>>>
>>> Changes from v2->v3:
>>> * Fixed issue which is in v2 that if no chosen timer node is
>>>   present in DT then timer init always fails without trying
>>>   first available timer.
>>>
>>> ---
>>>  doc/device-tree-bindings/chosen.txt | 43 +++++++++++++++++++++++++++++++++++++
>>>  drivers/timer/timer-uclass.c        | 41 +++++++++++++++++++++++++++++++++++
>>>  lib/time.c                          | 13 ++---------
>>>  3 files changed, 86 insertions(+), 11 deletions(-)
>>>  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..bf9a30a
>>> --- /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 at f00:115200";
>>> +       };
>>> +
>>> +       serial at 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 at f00";
>>> +       };
>>> +
>>> +       timer2 at f00 {
>>> +               compatible = "vendor,some-timer";
>>> +               reg = <0xf00 0x10>;
>>> +       };
>>> +};
>>> diff --git a/drivers/timer/timer-uclass.c b/drivers/timer/timer-uclass.c
>>> index aca421b..b6699f2 100644
>>> --- a/drivers/timer/timer-uclass.c
>>> +++ b/drivers/timer/timer-uclass.c
>>> @@ -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 +58,45 @@ u64 timer_conv_64(u32 count)
>>>         return ((u64)gd->timebase_h << 32) | gd->timebase_l;
>>>  }
>>>
>>> +int timer_init(void)
>>> +{
>>> +       const void *blob = gd->fdt_blob;
>>> +       struct udevice *dev = NULL;
>>> +       int node;
>>> +       int ret;
>>> +
>>> +       /* 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;
>>
>> Thanks for the quick v3!
>>
>>> +       } 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)) {
>>> +                               int ret = device_probe(dev);
>>
>> nits: no need to declare another ret. Just "ret = device_probe(dev)".
>
> Hmmm, yep not needed.
>
>>
>>> +                               if (ret)
>>> +                                       return ret;
>>> +                       }
>>> +               }
>>> +       }
>>> +
>>> +       if (dev) {
>>> +               gd->timer = dev;
>>> +               return 0;
>>> +       }
>>> +
>>> +       return -ENODEV;
>>> +}
>>> +
>>>  UCLASS_DRIVER(timer) = {
>>>         .id             = UCLASS_TIMER,
>>>         .name           = "timer",
>>> diff --git a/lib/time.c b/lib/time.c
>>> index f37a662..d4060f1 100644
>>> --- a/lib/time.c
>>> +++ b/lib/time.c
>>> @@ -43,17 +43,8 @@ extern unsigned long __weak timer_read_counter(void);
>>>  #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;
>>> -       }
>>> +       if (!gd->timer)
>>> +               return timer_init();
>>
>> What about my comments in v2, that make timer_init() static or just
>> move codes in timer_init() into this dm_timer_init()?
>
> Oops, missed :)
>
> The timer_init() code can be moved to dm_timer_init(), but since it
> provides timer uclass functionality I kept the code in timer-uclass driver.
>
> Now since dm_timer_init() doesn't have any thing other than calling
> timer_init, I will move the dm_timer_init() to timer_uclass and move
> timer_init code to it.
>
> Regards
> Mugunthan V N

Can you please add these changes in a follow-up commit? I'd like to
apply this series.

Applied to u-boot-dm, thanks!