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/*
* Copyright (C) 2025 Michael Brown <mbrown@fensystems.co.uk>.
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful, but
* WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
* 02110-1301, USA.
*
* You can also choose to distribute this program under the terms of
* the Unmodified Binary Distribution Licence (as given in the file
* COPYING.UBDL), provided that you have satisfied its requirements.
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdlib.h>
#include <errno.h>
#include <ipxe/gpio.h>
/** @file
*
* General purpose I/O
*
*/
/** List of GPIO controllers */
static LIST_HEAD ( all_gpios );
/**
* Allocate GPIO controller
*
* @v count Number of GPIO pins
* @v priv_len Size of driver-private data
* @ret gpios GPIO controller, or NULL
*/
struct gpios * alloc_gpios ( unsigned int count, size_t priv_len ) {
struct gpios *gpios;
struct gpio *gpio;
size_t len;
unsigned int i;
/* Allocate and initialise structure */
len = ( sizeof ( *gpios ) + ( count * sizeof ( *gpio ) ) + priv_len );
gpios = zalloc ( len );
if ( ! gpios )
return NULL;
gpios->count = count;
gpios->gpio = ( ( ( void * ) gpios ) + sizeof ( *gpios ) );
gpios->priv = ( ( ( void * ) gpios ) + sizeof ( *gpios ) +
( count * sizeof ( *gpio ) ) );
/* Initialise GPIO pins */
for ( i = 0 ; i < count ; i++ ) {
gpio = &gpios->gpio[i];
gpio->gpios = gpios;
gpio->index = i;
}
return gpios;
}
/**
* Register GPIO controller
*
* @v gpios GPIO controller
* @ret rc Return status code
*/
int gpios_register ( struct gpios *gpios ) {
/* Add to list of GPIO controllers */
gpios_get ( gpios );
list_add_tail ( &gpios->list, &all_gpios );
DBGC ( gpios, "GPIO %s registered with %d GPIOs\n",
gpios->dev->name, gpios->count );
return 0;
}
/**
* Unregister GPIO controller
*
* @v gpios GPIO controller
*/
void gpios_unregister ( struct gpios *gpios ) {
/* Remove from list of GPIO controllers */
DBGC ( gpios, "GPIO %s unregistered\n", gpios->dev->name );
list_del ( &gpios->list );
gpios_put ( gpios );
}
/**
* Find GPIO controller
*
* @v bus_type Bus type
* @v location Bus location
* @ret gpios GPIO controller, or NULL
*/
struct gpios * gpios_find ( unsigned int bus_type, unsigned int location ) {
struct gpios *gpios;
/* Scan through list of registered GPIO controllers */
list_for_each_entry ( gpios, &all_gpios, list ) {
if ( ( gpios->dev->desc.bus_type == bus_type ) &&
( gpios->dev->desc.location == location ) )
return gpios;
}
return NULL;
}
/**
* Get null GPIO input value
*
* @v gpios GPIO controller
* @v gpio GPIO pin
* @ret active Pin is in the active state
*/
static int null_gpio_in ( struct gpios *gpios __unused,
struct gpio *gpio __unused ) {
return 0;
}
/**
* Set null GPIO output value
*
* @v gpios GPIO controller
* @v gpio GPIO pin
* @v active Set pin to active state
*/
static void null_gpio_out ( struct gpios *gpios __unused,
struct gpio *gpio __unused, int active __unused ) {
/* Nothing to do */
}
/**
* Configure null GPIO pin
*
* @v gpios GPIO controller
* @v gpio GPIO pin
* @v config Configuration
* @ret rc Return status code
*/
static int null_gpio_config ( struct gpios *gpios __unused,
struct gpio *gpio __unused,
unsigned int config __unused ) {
return -ENODEV;
}
/** Null GPIO operations */
struct gpio_operations null_gpio_operations = {
.in = null_gpio_in,
.out = null_gpio_out,
.config = null_gpio_config,
};
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