[U-Boot] [PATCH v2 07/12] exynos5: support tps65090 pmic

[Simon Glass]

Hi David,

On 22 May 2014 08:24, David Nelson <djhenjin1 at gmail.com> wrote:
>
> On 14-05-22 11:27 AM, Simon Glass wrote:
>>
>> Hi Minkyu,
>>
>> On 21 May 2014 15:20, Minkyu Kang <mk7.kang at samsung.com> wrote:
>>>
>>> On 22/05/14 03:58, Simon Glass wrote:
>>>>
>>>> Hi Minkyu,
>>>>
>>>> On 21 May 2014 00:05, Minkyu Kang <mk7.kang at samsung.com> wrote:
>>>>>
>>>>> On 20/05/14 20:47, Simon Glass wrote:
>>>>>>
>>>>>> Hi Minkyu,
>>>>>>
>>>>>> On 15 May 2014 00:51, Minkyu Kang <mk7.kang at samsung.com> wrote:
>>>>>>>
>>>>>>> On 03/04/14 08:24, Simon Glass wrote:
>>>>>>>>
>>>>>>>> From: Aaron Durbin <adurbin at chromium.org>
>>>>>>>>
>>>>>>>> The TSP65090 is a PMIC on some exynos5 boards. The init function is
>>>>>>>> called for the TPS65090 pmic. If that device is not a part of the
>>>>>>>> device
>>>>>>>> tree (returns -ENODEV) then continue. Otherwise return a failure.
>>>>>>>>
>>>>>>>> Signed-off-by: Aaron Durbin <adurbin at chromium.org>
>>>>>>>> Signed-off-by: Simon Glass <sjg at chromium.org>
>>>>>>>> Reviewed-by: Simon Glass <sjg at chromium.org>
>>>>>>>> ---
>>>>>>>>
>>>>>>>> Changes in v2:
>>>>>>>> - Move code to exynos5-dt.c
>>>>>>>> - Fix comment style
>>>>>>>> - Add #ifdef around tps65090 code
>>>>>>>>
>>>>>>>>   board/samsung/smdk5250/exynos5-dt.c | 13 +++++++++++++
>>>>>>>>   1 file changed, 13 insertions(+)
>>>>>>>>
>>>>>>>> diff --git a/board/samsung/smdk5250/exynos5-dt.c
>>>>>>>> b/board/samsung/smdk5250/exynos5-dt.c
>>>>>>>> index 1a64b9b..2c1cf8a 100644
>>>>>>>> --- a/board/samsung/smdk5250/exynos5-dt.c
>>>>>>>> +++ b/board/samsung/smdk5250/exynos5-dt.c
>>>>>>>> @@ -20,6 +20,7 @@
>>>>>>>>   #include <asm/arch/sromc.h>
>>>>>>>>   #include <power/pmic.h>
>>>>>>>>   #include <power/max77686_pmic.h>
>>>>>>>> +#include <power/tps65090_pmic.h>
>>>>>>>>   #include <tmu.h>
>>>>>>>>
>>>>>>>>   DECLARE_GLOBAL_DATA_PTR;
>>>>>>>> @@ -164,7 +165,19 @@ int exynos_power_init(void)
>>>>>>>>
>>>>>>>>   #ifdef CONFIG_POWER_MAX77686
>>>>>>>>        ret = max77686_init();
>>>>>>>> +     if (ret)
>>>>>>>> +             return ret;
>>>>>>>>   #endif
>>>>>>>> +#ifdef CONFIG_POWER_TPS65090
>>>>>>>> +     /*
>>>>>>>> +      * The TPS65090 may not be in the device tree. If so, it is
>>>>>>>> not
>>>>>>>> +      * an error.
>>>>>>>
>>>>>>> Then, how we can initialise the tps65090?
>>>>>>
>>>>>> It is initialised if a suitable node is found in the device tree. If
>>>>>> the device tree does not have it, then the hardware is assumed to not
>>>>>> have this chip.
>>>>>
>>>>> then I think, it's an error.
>>>>> Why you said, it is not an error?
>>>>
>>>> I may be misunderstanding your question, but I'll try to answer what I
>>>> think you are asking.
>>>>
>>>> The device tree contains nodes for hardware in the machine that you
>>>> want to initialise, and information about each one. Devices can be
>>>> enabled or disabled by including or removing this information from the
>>>> device tree (or marking a device disabled with a status = "disabled"
>>>> property in the node).
>>>>
>>>> The tps65090 chip is not used in all exynos5-dt boards, but is used in
>>>> some. For example smdk5250 does not have it, but snow does. So we use
>>>> the device tree to specify the difference, including (on snow) things
>>>> like the tps65090, the display bridge chip, etc.
>>>>
>>> Hm, it doesn't make sense.
>>> Then it(#define CONFIG_POWER_TPS65090) should go into each config files.
>>> Not in exynos5-dt.h.
>>> Please modify it and patch 6/12 also.
>>
>> The way it works at present is that there is a single exynos5-dt.h
>> file which is used by all exynos5 boards. To the extent possible we
>> have avoided putting particular features in things like snow.h and
>> smdk5250.h - they just include exynos5-dt.h without changes.
>>
>> The idea is that we can have one U-Boot binary that runs on any
>> exynos5 device, rather than lots of different options. This makes it
>> much easier to test changes sine we only need to build it once. If
>> every exynos5 board has different #defines then there are more
>> combinations to build and test. This is similar to what the kernel
>> does with arch/arm/mach-exynos/mach-exynos5-dt.c.
>>
>> Using this approach the only differences between smdk5250, daisy,
>> snow, spring, etc. are in the device tree. I'd really like to avoid
>> changing this now. It is easy enough for people to add their own
>> private variants of these locally if they want to, but for mainline I
>> believe it is better to be more generic.
>>
>> Regards,
>> Simon
>> _______________________________________________
>> U-Boot mailing list
>> U-Boot at lists.denx.de
>> http://lists.denx.de/mailman/listinfo/u-boot
>
> Simon,
>
> Would you say that we are approaching a state where *all* exynos 5 boards
> will be ready? I ask because I have the Universal5420 aka sm-t520 and I
> could really use a bootloader for it so I am eacer to assist any way
> neccessary. (but i need a little direction because i am a noob)

I'm not familiar with that board. It doesn't seem to be in mainline /
have a device tree file in U-Boot or Linux. You may be able to get it
to boot just by trying one of the existing configs. If you need to
change a device tree file, you could send a patch.

Regards,
Simon