genode/repos/os/include/gpio/config.h
Norman Feske 17c79a9e23 base: avoid use of deprecated base/printf.h
Besides adapting the components to the use of base/log.h, the patch
cleans up a few base headers, i.e., it removes unused includes from
root/component.h, specifically base/heap.h and
ram_session/ram_session.h. Hence, components that relied on the implicit
inclusion of those headers have to manually include those headers now.

While adjusting the log messages, I repeatedly stumbled over the problem
that printing char * arguments is ambiguous. It is unclear whether to
print the argument as pointer or null-terminated string. To overcome
this problem, the patch introduces a new type 'Cstring' that allows the
caller to express that the argument should be handled as null-terminated
string. As a nice side effect, with this type in place, the optional len
argument of the 'String' class could be removed. Instead of supplying a
pair of (char const *, size_t), the constructor accepts a 'Cstring'.
This, in turn, clears the way let the 'String' constructor use the new
output mechanism to assemble a string from multiple arguments (and
thereby getting rid of snprintf within Genode in the near future).

To enforce the explicit resolution of the char * ambiguity, the 'char *'
overload of the 'print' function is marked as deleted.

Issue #1987
2016-08-29 17:27:10 +02:00

83 lines
2.1 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();
Genode::log("gpio ", num, " "
"mode ", Genode::Cstring(mode), " "
"value=", value);
} catch(Genode::Xml_node::Nonexistent_attribute) {
Genode::warning("missing attribute. Ignore node.");
} catch(Gpio::Invalid_gpio_number) {
Genode::warning("invalid GPIO number ", num, ", ignore node");
}
if (gpio_node.last("gpio")) break;
}
}
catch (Genode::Xml_node::Nonexistent_sub_node) {
Genode::warning("no GPIO config");
}
}
#endif /* _INCLUDE__GPIO__CONFIG_H_ */