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

Dan Murphy
2019-04-23T15:31:41Z

Brian

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.

Dan

> led@0 {
> reg = <0>;
> led-sources = <0 1>;
> label = "lcd-backlight";
> default-brightness = <200>;
> };
>
> led@1 {
> reg = <1>;
> default-brightness = <150>;
> };
>
> Brian
>