From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751878AbdCCPuh (ORCPT ); Fri, 3 Mar 2017 10:50:37 -0500 Received: from www381.your-server.de ([78.46.137.84]:45040 "EHLO www381.your-server.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751560AbdCCPue (ORCPT ); Fri, 3 Mar 2017 10:50:34 -0500 Subject: Re: [PATCH v3 6/6] iio: adc: stm32: add support for EXTI trigger To: Fabrice Gasnier , jic23@kernel.org, linux@armlinux.org.uk, robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org References: <1488300679-3259-1-git-send-email-fabrice.gasnier@st.com> <1488300679-3259-7-git-send-email-fabrice.gasnier@st.com> <5be44ed9-2c86-ac51-d964-d231d5ca62fa@metafoo.de> Cc: linux-iio@vger.kernel.org, mark.rutland@arm.com, mcoquelin.stm32@gmail.com, alexandre.torgue@st.com, knaack.h@gmx.de, pmeerw@pmeerw.net, benjamin.gaignard@linaro.org, benjamin.gaignard@st.com, linus.walleij@linaro.org From: Lars-Peter Clausen Message-ID: <9f39b0ac-a6fb-8a9f-7280-c6718b56aabe@metafoo.de> Date: Fri, 3 Mar 2017 16:46:39 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Icedove/45.6.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-Authenticated-Sender: lars@metafoo.de Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03/03/2017 02:00 PM, Fabrice Gasnier wrote: > On 03/03/2017 12:45 PM, Lars-Peter Clausen wrote: >> On 02/28/2017 05:51 PM, Fabrice Gasnier wrote: >>> EXTi (external interrupt) signal can be routed internally as trigger >>> source for ADC conversions: STM32F4 ADC can use EXTI11. >>> >>> Retrieve interrupt trigger from DT, so it can be muxed into ADC IP, >>> via extsel. >> >> Hi, >> >> Sorry, I have some trouble understanding the specifics of this. Is EXTI a >> hardware input signal into the ADC that automatically triggers a conversion >> when asserted? If yes how is it configured which external signal is used >> here. Your bindings suggest that any GPIO can be used, but the driver only >> differentiates between EXTI on or EXTI off. > Hi Lars, > > Yes, STM32 EXTI is external interrupt/event line. In case of STM32 ADC, > EXTI11 signal can be used to start a conversion. In this case, it must > be selected inside ADC IP using extsel bitfield. This EXTI11 line can > mapped from any GPIO bank A,B... line 11 (e.g. PA11 or PB11...) by using > interrupt binding. > This is why I expose this in DT. How is the mapping? That's the part I don't understand. How does requesting the IRQ for the GPIO as a generic software IRQ establish the hardware connection between the GPIO block and the ADC? From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lars-Peter Clausen Subject: Re: [PATCH v3 6/6] iio: adc: stm32: add support for EXTI trigger Date: Fri, 3 Mar 2017 16:46:39 +0100 Message-ID: <9f39b0ac-a6fb-8a9f-7280-c6718b56aabe@metafoo.de> References: <1488300679-3259-1-git-send-email-fabrice.gasnier@st.com> <1488300679-3259-7-git-send-email-fabrice.gasnier@st.com> <5be44ed9-2c86-ac51-d964-d231d5ca62fa@metafoo.de> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: Fabrice Gasnier , jic23@kernel.org, linux@armlinux.org.uk, robh+dt@kernel.org, linux-arm-kernel@lists.infradead.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Cc: mark.rutland@arm.com, mcoquelin.stm32@gmail.com, benjamin.gaignard@linaro.org, alexandre.torgue@st.com, linux-iio@vger.kernel.org, linus.walleij@linaro.org, pmeerw@pmeerw.net, knaack.h@gmx.de, benjamin.gaignard@st.com List-Id: devicetree@vger.kernel.org On 03/03/2017 02:00 PM, Fabrice Gasnier wrote: > On 03/03/2017 12:45 PM, Lars-Peter Clausen wrote: >> On 02/28/2017 05:51 PM, Fabrice Gasnier wrote: >>> EXTi (external interrupt) signal can be routed internally as trigger >>> source for ADC conversions: STM32F4 ADC can use EXTI11. >>> >>> Retrieve interrupt trigger from DT, so it can be muxed into ADC IP, >>> via extsel. >> >> Hi, >> >> Sorry, I have some trouble understanding the specifics of this. Is EXTI a >> hardware input signal into the ADC that automatically triggers a conversion >> when asserted? If yes how is it configured which external signal is used >> here. Your bindings suggest that any GPIO can be used, but the driver only >> differentiates between EXTI on or EXTI off. > Hi Lars, > > Yes, STM32 EXTI is external interrupt/event line. In case of STM32 ADC, > EXTI11 signal can be used to start a conversion. In this case, it must > be selected inside ADC IP using extsel bitfield. This EXTI11 line can > mapped from any GPIO bank A,B... line 11 (e.g. PA11 or PB11...) by using > interrupt binding. > This is why I expose this in DT. How is the mapping? That's the part I don't understand. How does requesting the IRQ for the GPIO as a generic software IRQ establish the hardware connection between the GPIO block and the ADC? From mboxrd@z Thu Jan 1 00:00:00 1970 From: lars@metafoo.de (Lars-Peter Clausen) Date: Fri, 3 Mar 2017 16:46:39 +0100 Subject: [PATCH v3 6/6] iio: adc: stm32: add support for EXTI trigger In-Reply-To: References: <1488300679-3259-1-git-send-email-fabrice.gasnier@st.com> <1488300679-3259-7-git-send-email-fabrice.gasnier@st.com> <5be44ed9-2c86-ac51-d964-d231d5ca62fa@metafoo.de> Message-ID: <9f39b0ac-a6fb-8a9f-7280-c6718b56aabe@metafoo.de> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org On 03/03/2017 02:00 PM, Fabrice Gasnier wrote: > On 03/03/2017 12:45 PM, Lars-Peter Clausen wrote: >> On 02/28/2017 05:51 PM, Fabrice Gasnier wrote: >>> EXTi (external interrupt) signal can be routed internally as trigger >>> source for ADC conversions: STM32F4 ADC can use EXTI11. >>> >>> Retrieve interrupt trigger from DT, so it can be muxed into ADC IP, >>> via extsel. >> >> Hi, >> >> Sorry, I have some trouble understanding the specifics of this. Is EXTI a >> hardware input signal into the ADC that automatically triggers a conversion >> when asserted? If yes how is it configured which external signal is used >> here. Your bindings suggest that any GPIO can be used, but the driver only >> differentiates between EXTI on or EXTI off. > Hi Lars, > > Yes, STM32 EXTI is external interrupt/event line. In case of STM32 ADC, > EXTI11 signal can be used to start a conversion. In this case, it must > be selected inside ADC IP using extsel bitfield. This EXTI11 line can > mapped from any GPIO bank A,B... line 11 (e.g. PA11 or PB11...) by using > interrupt binding. > This is why I expose this in DT. How is the mapping? That's the part I don't understand. How does requesting the IRQ for the GPIO as a generic software IRQ establish the hardware connection between the GPIO block and the ADC?