On Tue, Oct 21, 2014 at 2:30 AM, Arnd Bergmann <arnd@xxxxxxxx> wrote: > On Tuesday 21 October 2014 11:22:40 Thomas Gleixner wrote: >> On Thu, 4 Sep 2014, Bjorn Andersson wrote: >> >> > On Tue, Aug 19, 2014 at 1:23 PM, Bjorn Andersson >> > <bjorn.andersson@xxxxxxxxxxxxxx> wrote: >> > > Introduce the irq_read_line() function to allow device drivers to read >> > > the current logical state of an input when the hardware only exposes >> > > this through status bits in the interrupt controller. >> > > >> > > The new function is backed by a new callback function in the irq_chip - >> > > irq_read_line() - that can be implemented by irq_chips that owns such >> > > status bits. >> > > >> > > Based on rfc patch from April 2011 by Abhijeet. >> > > >> > > Cc: Abhijeet Dharmapurikar <adharmap@xxxxxxxxxxxxxx> >> > > Signed-off-by: Bjorn Andersson <bjorn.andersson@xxxxxxxxxxxxxx> >> > >> > ping? >> >> Sorry, slipped through the cracks. I was talking about this to Marc >> last week and he needs it for yet another reason. He had some thoughts >> about the state representation, so I wait for him to comment. > > I looked up my older email as well and found which gpio driver had the > requirement to get the irq status from the upstream controller. It was > "gpio: Add APM X-Gene standby GPIO controller driver". I'm adding the > APM developers on Cc here so they can participate in the discussion. > > As a brief summary: APM have a GPIO driver that needs to read the status > from the ARM GIC in order to implement gpio_get_value. Thanks, we will rebase our standby gpio patch on top of this change. The KVM hypervisor > needs multiple bits from the GIC in order to implement suspend/resume, > and Qualcomm MSM (as Bjorn wrote above) also needs to expose the status > of the IRQ line like APM does. > > These should all use the same interface for the interrupt controller, > but the interface still needs to be added. > > Arnd > CONFIDENTIALITY NOTICE: This e-mail message, including any attachments, > is for the sole use of the intended recipient(s) and contains information > that is confidential and proprietary to Applied Micro Circuits Corporation or its subsidiaries. > It is to be used solely for the purpose of furthering the parties' business relationship. > All unauthorized review, use, disclosure or distribution is prohibited. > If you are not the intended recipient, please contact the sender by reply e-mail > and destroy all copies of the original message. > -- To unsubscribe from this list: send the line "unsubscribe linux-arm-msm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
