On Thu, Oct 22, 2020 at 9:05 PM Nicolas Saenz Julienne
<nsaenzjulienne@xxxxxxx> wrote:
>
> Adds support to control the PWM bus available in official Raspberry Pi
> PoE HAT. Only RPi's co-processor has access to it, so commands have to
> be sent through RPi's firmware mailbox interface.
> drivers/pwm/pwm-raspberrypi.c | 221 ++++++++++++++++++++++++++++++++++
Name is completely confusing.
Please, make it unique enough to understand that this is exactly the
device it serves for.
For example, pwm-rpi-poe is better.
...
> + * - Only normal polarity
Can't it be emulated? Isn't it 100% - duty cycle % ?
> +#include <linux/module.h>
> +#include <linux/of.h>
> +#include <linux/platform_device.h>
> +#include <linux/pwm.h>
...
> + ret = rpi_firmware_property(firmware, RPI_FIRMWARE_SET_POE_HAT_VAL,
> + &msg, sizeof(msg));
> + if (ret)
> + return ret;
> + else if (msg.ret)
Redundant 'else'
> + return -EIO;
...
> + ret = rpi_firmware_property(firmware, RPI_FIRMWARE_GET_POE_HAT_VAL,
> + &msg, sizeof(msg));
> + if (ret)
> + return ret;
> + else if (msg.ret)
Ditto.
> + return -EIO;
...
> + firmware_node = of_get_parent(dev->of_node);
> + if (!firmware_node) {
> + dev_err(dev, "Missing firmware node\n");
> + return -ENOENT;
> + }
> +
> + firmware = rpi_firmware_get(firmware_node);
> + of_node_put(firmware_node);
> + if (!firmware)
> + return -EPROBE_DEFER;
Looks like a hack.
...
> + ret = pwmchip_remove(&rpipwm->chip);
> + if (!ret)
> + rpi_firmware_put(rpipwm->firmware);
> +
> + return ret;
Can't you use the usual pattern?
ret = ...
if (ret)
return ret;
...
return 0;
--
With Best Regards,
Andy Shevchenko
