Re: [PATCH v5 3/3] backlight: lm3630a: add firmware node support

Dan Murphy
2019-04-23T19:02:51Z

Brian

On 4/23/19 11:00 AM, Brian Masney wrote:
> On Tue, Apr 23, 2019 at 10:31:41AM -0500, Dan Murphy wrote:
>> On 4/23/19 9:01 AM, Brian Masney wrote:
>>> On Tue, Apr 23, 2019 at 08:49:20AM -0500, Dan Murphy wrote:
>>>>> +static int lm3630a_parse_led_sources(struct fwnode_handle *node,
>>>>> + int default_led_sources)
>>>>> +{
>>>>> + u32 sources[LM3630A_NUM_SINKS];
>>>>> + int ret, num_sources, i;
>>>>> +
>>>>> + num_sources = fwnode_property_read_u32_array(node, "led-sources", NULL,
>>>>> + 0);
>>>>> + if (num_sources < 0)
>>>>> + return default_led_sources;
>>>>> + else if (num_sources > ARRAY_SIZE(sources))
>>>>> + return -EINVAL;
>>>>> +
>>>>> + ret = fwnode_property_read_u32_array(node, "led-sources", sources,
>>>>> + num_sources);
>>>>> + if (ret)
>>>>> + return ret;
>>>>> +
>>>>> + for (i = 0; i < num_sources; i++) {
>>>>> + if (sources[i] < LM3630A_SINK_0 || sources[i] > LM3630A_SINK_1)
>>>>> + return -EINVAL;
>>>>> +
>>>>> + ret |= BIT(sources[i]);
>>>>> + }
>>>>> +
>>>>> + return ret;
>>>>> +}
>>>>> +
>>>>> +static int lm3630a_parse_bank(struct lm3630a_platform_data *pdata,
>>>>> + struct fwnode_handle *node, int *seen_led_sources)
>>>>
>>>> Why is seen_led_sources passed in here?
>>>> It is initialized on the stack in lm3630a_parse_node but the variable is never referenced in that API.
>>>
>>> It's to see all of the led-sources that are configured across all of the
>>> banks. If it is just in lm3630a_parse_bank(), then it won't catch the
>>> following invalid configuration:
>>>
>>
>> Ok I see what it is for now.
>>
>> Not sure why it is declared as a pointer though.
>
> It's so that lm3630a_parse_bank() can update that value with the
> led-sources that have been seen. Otherwise, the changes wouldn't make
> their way back out to the outer function.
>

OK. Thats another way to do it. I may have just done a return with the value.

Otherwise

Reviewed-by: Dan Murphy <dmurphy@ti.com>

> Brian
>