Re: [PATCH v2 7/7] leds: Add support for RTL8231 LED scan matrix

Andy Shevchenko
2021-05-17T22:01:03Z

On Mon, May 17, 2021 at 10:28 PM Sander Vanheule <sander@svanheule.net> wrote:
>
> Both single and bi-color scanning modes are supported. The driver will
> verify that the addresses are valid for the current mode, before
> registering the LEDs. LEDs can be turned on, off, or toggled at one of
> six predefined rates from 40ms to 1280ms.
>
> Implements a platform device for use as child device with RTL8231 MFD,

as a child

> and uses the parent regmap to access the required registers.

...

> + When built as a module, this module will be named rtl8231_leds.

Again, what it's written here is not what is in Makefile.

> +obj-$(CONFIG_LEDS_RTL8231) += leds-rtl8231.o

...

> +/**
> + * struct led_toggle_rate - description of an LED blinking mode
> + * @interval: LED toggle rate in ms
> + * @mode: Register field value used to active this mode

activate

> + *
> + * For LED hardware accelerated blinking, with equal on and off delay.
> + * Both delays are given by @interval, so the interval at which the LED blinks
> + * (i.e. turn on and off once) is double this value.
> + */

...

> +static unsigned int rtl8231_led_current_interval(struct rtl8231_led *pled)
> +{
> + unsigned int mode;

> + unsigned int i = 0;

This...

> + if (regmap_field_read(pled->reg_field, &mode))
> + return 0;
> +
> + while (i < pled->modes->num_toggle_rates && mode != pled->modes->toggle_rates[i].mode)
> + i++;

...and this will be better as a for-loop.

> + if (i < pled->modes->num_toggle_rates)
> + return pled->modes->toggle_rates[i].interval;

> + else

Redundant.

> + return 0;
> +}

...

> + unsigned int i = 0;

As per above.

...

> + interval = 500;

interval_ms

> + /*
> + * If the current mode is blinking, choose the delay that (likely) changed.
> + * Otherwise, choose the interval that would have the same total delay.
> + */
> + interval = rtl8231_led_current_interval(pled);

> +

Redundant blank line.

> + if (interval > 0 && interval == *delay_off)
> + interval = *delay_on;
> + else if (interval > 0 && interval == *delay_on)
> + interval = *delay_off;
> + else
> + interval = (*delay_on + *delay_off) / 2;
> + }

...

> + u32 addr[2];
> + int err;
> +

> + if (!fwnode_property_count_u32(fwnode, "reg"))

err = fwnode_property_count_u32(...);
if (err < 0)
return err;
if (err == 0)
return -ENODEV;

> + return -ENODEV;
> +
> + err = fwnode_property_read_u32_array(fwnode, "reg", addr, ARRAY_SIZE(addr));

If count returns 1? What's the point of counting if you always want two?

> + if (err)
> + return err;
> +
> + *addr_port = addr[0];
> + *addr_led = addr[1];
> +
> + return 0;
> +}

...

> + pled = devm_kzalloc(dev, sizeof(*pled), GFP_KERNEL);
> + if (IS_ERR(pled))

Wrong.

> + return PTR_ERR(pled);

...

> + err = rtl8231_led_read_address(fwnode, &port_index, &led_index);
> +

Redundant blank line.

> + if (err) {
> + dev_err(dev, "LED address invalid\n");
> + return err;

> + } else if (led_index >= RTL8231_NUM_LEDS || port_index >= port_counts[led_index]) {

Redundant 'else'

> + dev_err(dev, "LED address (%d.%d) invalid\n", port_index, led_index);
> + return -ENODEV;
> + }

...

> + map = dev_get_regmap(dev->parent, NULL);
> + if (IS_ERR_OR_NULL(map)) {

Split it into two conditionals.

> + dev_err(dev, "failed to retrieve regmap\n");
> + if (!map)
> + return -ENODEV;
> + else
> + return PTR_ERR(map);
> + }

...

> + if (!device_property_match_string(dev, "realtek,led-scan-mode", "single-color")) {

It seems that device_property_match_string() and accompanying
functions have wrong description of returned codes, i.e. it returns
the index of the matched string. It's possible that some APIs are
broken (but I believe that the former is the case).

That said, I think the proper comparison should be >= 0.

> + port_counts = rtl8231_led_port_counts_single;
> + regmap_update_bits(map, RTL8231_REG_FUNC0,
> + RTL8231_FUNC0_SCAN_MODE, RTL8231_FUNC0_SCAN_SINGLE);
> + } else if (!device_property_match_string(dev, "realtek,led-scan-mode", "bi-color")) {

Ditto.

> + port_counts = rtl8231_led_port_counts_bicolor;
> + regmap_update_bits(map, RTL8231_REG_FUNC0,
> + RTL8231_FUNC0_SCAN_MODE, RTL8231_FUNC0_SCAN_BICOLOR);
> + } else {
> + dev_err(dev, "scan mode missing or invalid\n");
> + return -EINVAL;
> + }

--
With Best Regards,
Andy Shevchenko