From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Message-ID: <9e4733910809101039l39eed2cdl43b2004bee334687@mail.gmail.com> Date: Wed, 10 Sep 2008 13:39:34 -0400 From: "Jon Smirl" To: "Wolfgang Grandegger" Subject: Re: interrupt cells on mpc5200 In-Reply-To: <48C7FBCD.10803@grandegger.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 References: <9e4733910809100940g400bab3ck6f68ee24ae8d4573@mail.gmail.com> <48C7FBCD.10803@grandegger.com> Cc: linuxppc-dev List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Wed, Sep 10, 2008 at 12:54 PM, Wolfgang Grandegger wrote: > Jon Smirl wrote: >> mpc5200 interrupts have three cells in the device tree. How are these >> interpreted? >> Middle one is the interrupt number. Last one seems to always be zero. >> What does the first one do, edge/level? >> >> I searched through /Documentation and could find anything about three >> cells for interrupts. >> >> I understand the first one for gpio_wkup on interrupt 8. How does a >> gpio_wkup generate an interrupt on interrupt 3? >> >> gpio_wkup: gpio-wkup@c00 { >> compatible = "fsl,mpc5200b-gpio-wkup","fsl,mpc5200-gpio-wkup"; >> reg = <0xc00 0x40>; >> interrupts = <0x1 0x8 0x0 0x0 0x3 0x0>; >> interrupt-parent = <&mpc5200_pic>; >> gpio-controller; >> #gpio-cells = <2>; >> }; > > See > http://lxr.linux.no/linux+v2.6.26.5/Documentation/powerpc/mpc52xx-device-tree-bindings.txt#L263 Why was I too blind to see that file? So there must be someway to turn a gpio_wkup into a critical interrupt which causes the interrupt 3 which is a feature I don't need. Any hints on a good way to measure the length of pulses? They are between 500us and 2ms long. I was thinking of using an interrupt on the leading edge, starting a timer, and then flipping the gpio to cause an interrupt on the trailing edge. I don't need extreme accuracy. -- Jon Smirl jonsmirl@gmail.com