On Wed, Jun 5, 2024 at 9:00 PM Andy Shevchenko <andy.shevchenko@xxxxxxxxx> wrote: > > On Wed, Jun 5, 2024 at 7:19 PM Marek Behún <kabel@xxxxxxxxxx> wrote: > > > > Add support for true random number generator provided by the MCU. > > New Omnia boards come without the Atmel SHA204-A chip. Instead the > > crypto functionality is provided by new microcontroller, which has > > a TRNG peripheral. > > +Cc: Bart for gpiochip_get_desc() usage. > > ... > > > +#include <linux/bitfield.h> > > +#include <linux/completion.h> > > + errno.h > > > +#include <linux/gpio/consumer.h> > > +#include <linux/gpio/driver.h> > > +#include <linux/hw_random.h> > > +#include <linux/i2c.h> > > +#include <linux/interrupt.h> > > +#include <linux/minmax.h> > > +#include <linux/module.h> > > +#include <linux/string.h> > > > +#include <linux/turris-omnia-mcu-interface.h> > > As per other patches. > > > +#include <linux/types.h> > > + > > +#include "turris-omnia-mcu.h" > > ... > > > + irq_idx = omnia_int_to_gpio_idx[__bf_shf(OMNIA_INT_TRNG)]; > > + irq = gpiod_to_irq(gpiochip_get_desc(&mcu->gc, irq_idx)); > > + if (irq < 0) > > + return dev_err_probe(dev, irq, "Cannot get TRNG IRQ\n"); > > Okay, it's a bit more complicated than that. The gpiochip_get_desc() > shouldn't be used. Bart, what can you suggest to do here? Opencoding > it doesn't sound to me a (fully) correct approach in a long term. > Andy's worried about reference counting of the GPIO device. Maybe you should just ref the GPIO device in irq_request_resources() and unref it in irq_release_resources()? Then you could use gpiochip_get_desc() just fine. Bart
