lkml.org 
[lkml]   [2018]   [Jun]   [28]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: [PATCH v5 1/6] ARM: at91: add TCB registers definitions
From
Date
On 28/06/2018 20:34, Alexandre Belloni wrote:
> On 28/06/2018 17:15:39+0200, Daniel Lezcano wrote:
>> On 19/06/2018 23:19, Alexandre Belloni wrote:
>>> Add registers and bits definitions for the timer counter blocks found on
>>> Atmel ARM SoCs.
>>>
>>> Tested-by: Alexander Dahl <ada@thorsis.com>
>>> Tested-by: Andras Szemzo <szemzo.andras@gmail.com>
>>> Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
>>> ---
>>> include/soc/at91/atmel_tcb.h | 216 +++++++++++++++++++++++++++++++++++
>>
>> Is the header necessary ? Can it be moved in the .c ?
>>
>
> Ultimately, the clocksource driver will not be the only one to use it.
> There is the pwm driver that will be converted (it was converted in the
> first version of the series). and then there is a counter driver that
> will be submitted once the subsystem is upstreamed.

Ok.

>>> 1 file changed, 216 insertions(+)
>>> create mode 100644 include/soc/at91/atmel_tcb.h
>>>
>>> diff --git a/include/soc/at91/atmel_tcb.h b/include/soc/at91/atmel_tcb.h
>>> new file mode 100644
>>> index 000000000000..3ed66031fc76
>>> --- /dev/null
>>
>> [ ... ]
>>
>>> +static inline struct clk *tcb_clk_get(struct device_node *node, int channel)
>>> +{
>>> + struct clk *clk;
>>> + char clk_name[] = "t0_clk";
>>> +
>>> + clk_name[1] += channel;
>>
>> clever :)
>>
>>> + clk = of_clk_get_by_name(node->parent, clk_name);
>>> + if (!IS_ERR(clk))
>>> + return clk;
>>> +
>>> + return of_clk_get_by_name(node->parent, "t0_clk");
>>
>> Why do you want to return clk from t0_clk if another channel is
>> requested ? This is prone to error.
>
> The newer TCBs only have one peripheral clocks. The current DT binding only
> have t0_clk in that case so whatever the channel, t0_clk is the correct
> one.
>
>>
>> I would clarify that at the caller level, if tcb_clk_get fails then try
>> with channel zero.
>
> This was hidden from the individual drivers by tclib but this can be
> open coded in the drivers.
>
>>
>>> +}
>>> +
>>> +static inline int tcb_irq_get(struct device_node *node, int channel)
>>
>> no inline
>>
>
> IIRC, removing the inline will make linking the kernel fail when there
> is more than 2 drivers using the TCBs but I'll try again. Or I can
> remove both those functions and open code as you suggest.

Yes, preferable to remove these functions.

>>> +{
>>> + int irq;
>>> +
>>> + irq = of_irq_get(node->parent, channel);
>>> + if (irq > 0)
>>> + return irq;
>>> +
>>> + return of_irq_get(node->parent, 0);
>>
>> Same comment than above.
>>
>>> +}
>>> +
>>> +static const u8 atmel_tc_divisors[5] = { 2, 8, 32, 128, 0, };
>>> +
>>> +struct atmel_tcb_info {
>>> + int bits;
>>> +};
>>> +
>>> +static const struct atmel_tcb_info atmel_tcb_infos[] = {
>>> + { .bits = 16 },
>>> + { .bits = 32 },
>>> +};
>>
>> Structuring the code with structure is a good practice. However, this is
>> too much :)
>>
>
> I was going to add the divisor there but as AVR32 is gone, this is
> indeed unnecessary.
>
>>> +static const struct of_device_id atmel_tcb_dt_ids[] = {
>>> + {
>>> + .compatible = "atmel,at91rm9200-tcb",
>>> + .data = &atmel_tcb_infos[0],
>>
>> .data = (void *)16;
>>
>>> + }, {
>>> + .compatible = "atmel,at91sam9x5-tcb",
>>> + .data = &atmel_tcb_infos[1],
>>> + }, {
>>> + /* sentinel */
>>> + }
>>> +};
>>> +
>>
>>
>>
>>> +#endif /* __SOC_ATMEL_TCB_H */
>>>
>>
>>
>> --
>> <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
>>
>> Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
>> <http://twitter.com/#!/linaroorg> Twitter |
>> <http://www.linaro.org/linaro-blog/> Blog
>>
>


--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog

\
 
 \ /
  Last update: 2018-06-28 21:56    [W:0.404 / U:0.056 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site