Messages in this thread | | | From | Andy Shevchenko <> | Date | Thu, 22 Oct 2020 21:53:35 +0300 | Subject | Re: [PATCH v2 10/10] pwm: Add Raspberry Pi Firmware based PWM bus |
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On Thu, Oct 22, 2020 at 9:05 PM Nicolas Saenz Julienne <nsaenzjulienne@suse.de> 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
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