From 4e47f91bf741e011a90ceb6241b8d78141709733 Mon Sep 17 00:00:00 2001 From: Lars Poeschel Date: Thu, 16 Jan 2014 11:44:15 +0100 Subject: gpio: mcp23s08: Add irq functionality for i2c chips This adds interrupt functionality for i2c chips to the driver. They can act as a interrupt-controller and generate interrupts, if the inputs change. This is tested with a mcp23017 chip on an arm based platform. v3: - be a bit more clear that the irq functionality is also available on spi versions of the chips, but the linux driver does not support this yet v2: - some more word about irq-mirror property in binding doc - use of_read_bool instead of of_find_property for "interrupt-contrller" and "irq-mirror" - cache the "interrupt-controller" for remove function - do set the irq-mirror bit only if device is marked as interrupt-controller - do create the irq mapping and setup of irq_desc of all possible interrupts in probe path instead of in gpio_to_irq - mark gpios as in use as interrupts in irq in irq_startup and unlock it in irq_shutdown - rename virq to child_irq - remove dev argument from mcp23s08_irq_setup function - move gpiochip_add before mcp23s08_irq_setup in probe path Signed-off-by: Lars Poeschel Signed-off-by: Linus Walleij --- .../devicetree/bindings/gpio/gpio-mcp23s08.txt | 28 +++++++++++++++++++++- 1 file changed, 27 insertions(+), 1 deletion(-) (limited to 'Documentation/devicetree/bindings/gpio') diff --git a/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt index daa30174bcc..3ddc7ccfe5f 100644 --- a/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt +++ b/Documentation/devicetree/bindings/gpio/gpio-mcp23s08.txt @@ -38,12 +38,38 @@ Required device specific properties (only for SPI chips): removed. - spi-max-frequency = The maximum frequency this chip is able to handle -Example I2C: +Optional properties: +- #interrupt-cells : Should be two. + - first cell is the pin number + - second cell is used to specify flags. +- interrupt-controller: Marks the device node as a interrupt controller. +NOTE: The interrupt functionality is only supported for i2c versions of the +chips. The spi chips can also do the interrupts, but this is not supported by +the linux driver yet. + +Optional device specific properties: +- microchip,irq-mirror: Sets the mirror flag in the IOCON register. Devices + with two interrupt outputs (these are the devices ending with 17 and + those that have 16 IOs) have two IO banks: IO 0-7 form bank 1 and + IO 8-15 are bank 2. These chips have two different interrupt outputs: + One for bank 1 and another for bank 2. If irq-mirror is set, both + interrupts are generated regardless of the bank that an input change + occured on. If it is not set, the interrupt are only generated for the + bank they belong to. + On devices with only one interrupt output this property is useless. + +Example I2C (with interrupt): gpiom1: gpio@20 { compatible = "microchip,mcp23017"; gpio-controller; #gpio-cells = <2>; reg = <0x20>; + + interrupt-parent = <&gpio1>; + interrupts = <17 IRQ_TYPE_LEVEL_LOW>; + interrupt-controller; + #interrupt-cells=<2>; + microchip,irq-mirror; }; Example SPI: -- cgit v1.2.3