On Thu, 2017-07-27 at 23:40 -0700, Tony Lindgren wrote: > * yegorslists@xxxxxxxxxxxxxx <yegorslists@xxxxxxxxxxxxxx> [170727 > 06:18]: > > From: Yegor Yefremov <yegorslists@xxxxxxxxxxxxxx> > > > > This patch series aims to reintroduce the mctrl_gpio helpers for > > 8250 > > UARTs. > > > > There are some UARTs that use GPIO signals as a wakeup-sourse. > > The first patch addresses this issue and tries to destinguish GPIO > > usage > > via searching for "wakeup-sourse" property. Though it must be > > decided whether > > this property is secure to use for this purpose. > > The wakeup-source part you should be able to handle pretty much > out of box with Linux generic wakeirqs if configured. See for example > drivers/i2c/i2c-core.c for the dev_pm_set_dedicated_wake_irq() part. Here are 3 cases: 1) out-of-band interrupt (usually GPIO) which can be wake source; 2) in-band interrupt (have not seen this for UART, though it's supported by tty framework for a long time AFAIU); 3) special case when Out-of-band interrupt uses the pin in UART pool of pins. We are talking here about case 3). > As long as the 8250 driver has runtime PM implemented As you remember it has not (the ugly hack which is used right now is not correct implementation of RPM). > it will wake > up the 8250 device. See above, in case 3) we would be able to achieve that when pin mode is switched to GPIO and back. I don't remember if OMAP uses this approach. > This should work just fine also with am335x gpios, just configure the > secondary wakeup gpio interrupt using interrupts-extended in device > tree. Typically the interrupts are named "irq" and "wakeup". And if > the > pin is used as gpio, you can just dev_pm_clear_wake_irq() during > runtime. I think this one is not related to case 3). > If having issues, we're still missing the wakeirq level configuration, > the patch below should do the trick there. > err = request_threaded_irq(irq, NULL, > handle_threaded_wake_irq, > - IRQF_ONESHOT, dev_name(dev), > wirq); > + irq_get_trigger_type(irq) | > IRQF_ONESHOT, This is not needed if you use DT or ACPI and framework (serial in this case) checks for interrupt correctly. -- Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> Intel Finland Oy -- To unsubscribe from this list: send the line "unsubscribe linux-serial" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
