genode/os/include/gpio/config.h
Stefan Kalkowski ca92984bcc Simplify GPIO session interface (fix #707)
Changes GPIO session interface to a one-GPIO-pin-per-session style. Moreover,
this commit introduces a generic driver interface for GPIO drivers. Thereby
generalizes root- and session component for GPIO.
2013-05-10 11:16:12 +02:00

79 lines
2.0 KiB
C++

/*
* \brief Access to GPIO driver configuration
* \author Stefan Kalkowski
* \date 2013-05-06
*
* Taken from the OMAP4 GPIO driver written by Ivan Loskutov.
*
* Configure GPIO
* Example:
* <config>
* <gpio num="123" mode="I"/>
* <gpio num="124" mode="O" value="0"/>
* </config>
*
* num - GPIO pin number
* mode - input(I) or output(O)
* value - output level (1 or 0), only for output mode
*/
/*
* Copyright (C) 2010-2013 Genode Labs GmbH
*
* This file is part of the Genode OS framework, which is distributed
* under the terms of the GNU General Public License version 2.
*/
#ifndef _INCLUDE__GPIO__CONFIG_H_
#define _INCLUDE__GPIO__CONFIG_H_
#include <base/exception.h>
#include <os/config.h>
#include <gpio/driver.h>
namespace Gpio {
class Invalid_gpio_number : Genode::Exception {};
class Invalid_mode : Genode::Exception {};
static void process_config(Gpio::Driver &driver);
}
void Gpio::process_config(Gpio::Driver &driver) {
try {
Genode::Xml_node gpio_node = Genode::config()->xml_node().sub_node("gpio");
for (;; gpio_node = gpio_node.next("gpio")) {
unsigned num = 0;
char mode[2] = {0};
unsigned value = 0;
try {
gpio_node.attribute("num").value(&num);
if (!driver.gpio_valid(num)) throw Invalid_gpio_number();
gpio_node.attribute("mode").value(mode, sizeof(mode));
if (mode[0] == 'O' || mode[0] == 'o') {
gpio_node.attribute("value").value(&value);
driver.write(num, value);
driver.direction(num, false);
} else if (mode[0] == 'I' || mode[0] == 'i') {
driver.direction(num, true);
} else throw Invalid_mode();
PINF("gpio %d mode %s value=%d", num, mode, value);
} catch(Genode::Xml_node::Nonexistent_attribute) {
PWRN("Missing attribute. Ignore node.");
} catch(Gpio::Invalid_gpio_number) {
PWRN("Invalid GPIO number %d. Ignore node", num);
}
if (gpio_node.is_last("gpio")) break;
}
}
catch (Genode::Xml_node::Nonexistent_sub_node) {
PWRN("No GPIO config");
}
}
#endif /* _INCLUDE__GPIO__CONFIG_H_ */