sysadmin/ipxe
1
0
Fork 0
mirror of https://github.com/ipxe/ipxe synced 2026-02-14 02:31:26 +03:00
Code Issues Packages Projects Releases Wiki Activity

[gpio] Add a framework for GPIO controllers

Browse Source 
Signed-off-by: Michael Brown <mcb30@ipxe.org>
This commit is contained in:
Michael Brown
2025-08-05 13:54:27 +01:00
parent 5f10b74555
commit 90fe3a2924
3 changed files with 365 additions and 0 deletions
Download Patch File Download Diff File Expand all files Collapse all files

165
src/core/gpio.c Normal file
View File

@@ -0,0 +1,165 @@
/*
* 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,
};

1
src/include/ipxe/errfile.h
View File

@@ -87,6 +87,7 @@ FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#define ERRFILE_efi_open ( ERRFILE_CORE | 0x002f0000 ) #define ERRFILE_efi_open ( ERRFILE_CORE | 0x002f0000 )
#define ERRFILE_efi_table ( ERRFILE_CORE | 0x00300000 ) #define ERRFILE_efi_table ( ERRFILE_CORE | 0x00300000 )
#define ERRFILE_efi_connect ( ERRFILE_CORE | 0x00310000 ) #define ERRFILE_efi_connect ( ERRFILE_CORE | 0x00310000 )
#define ERRFILE_gpio ( ERRFILE_CORE | 0x00320000 )
#define ERRFILE_eisa ( ERRFILE_DRIVER | 0x00000000 ) #define ERRFILE_eisa ( ERRFILE_DRIVER | 0x00000000 )
#define ERRFILE_isa ( ERRFILE_DRIVER | 0x00010000 ) #define ERRFILE_isa ( ERRFILE_DRIVER | 0x00010000 )

199
src/include/ipxe/gpio.h Normal file
View File

@@ -0,0 +1,199 @@
#ifndef _IPXE_GPIO_H
#define _IPXE_GPIO_H
/** @file
*
* General purpose I/O
*
*/
FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL );
#include <stdint.h>
#include <ipxe/list.h>
#include <ipxe/refcnt.h>
#include <ipxe/device.h>
/** A GPIO pin */
struct gpio {
/** GPIO controller */
struct gpios *gpios;
/** Pin index */
unsigned int index;
/** Configuration */
unsigned int config;
};
/** GPIO is active low
*
* This bit is chosen to match the devicetree standard usage.
*/
#define GPIO_CFG_ACTIVE_LOW 0x01
/** GPIO is an output */
#define GPIO_CFG_OUTPUT 0x0100
/** A GPIO controller */
struct gpios {
/** Reference count */
struct refcnt refcnt;
/** List of GPIO controllers */
struct list_head list;
/** Generic device */
struct device *dev;
/** Number of GPIOs */
unsigned int count;
/** Individual GPIOs */
struct gpio *gpio;
/** GPIO operations */
struct gpio_operations *op;
/** Driver-private data */
void *priv;
};
/** GPIO operations */
struct gpio_operations {
/**
* Get current GPIO input value
*
* @v gpios GPIO controller
* @v gpio GPIO pin
* @ret active Pin is in the active state
*/
int ( * in ) ( struct gpios *gpios, struct gpio *gpio );
/**
* Set current GPIO output value
*
* @v gpios GPIO controller
* @v gpio GPIO pin
* @v active Set pin to active state
*/
void ( * out ) ( struct gpios *gpios, struct gpio *gpio, int active );
/**
* Configure GPIO pin
*
* @v gpios GPIO controller
* @v gpio GPIO pin
* @v config Configuration
* @ret rc Return status code
*/
int ( * config ) ( struct gpios *gpios, struct gpio *gpio,
unsigned int config );
};
extern struct gpio_operations null_gpio_operations;
/**
* Get reference to GPIO controller
*
* @v gpios GPIO controller
* @ret gpios GPIO controller
*/
static inline __attribute__ (( always_inline )) struct gpios *
gpios_get ( struct gpios *gpios ) {
ref_get ( &gpios->refcnt );
return gpios;
}
/**
* Drop reference to GPIO controller
*
* @v gpios GPIO controller
*/
static inline __attribute__ (( always_inline )) void
gpios_put ( struct gpios *gpios ) {
ref_put ( &gpios->refcnt );
}
/**
* Get reference to GPIO pin
*
* @v gpio GPIO pin
* @ret gpio GPIO pin
*/
static inline __attribute__ (( always_inline )) struct gpio *
gpio_get ( struct gpio *gpio ) {
gpios_get ( gpio->gpios );
return gpio;
}
/**
* Drop reference to GPIO ping
*
* @v gpio GPIO pin
*/
static inline __attribute__ (( always_inline )) void
gpio_put ( struct gpio *gpio ) {
gpios_put ( gpio->gpios );
}
/**
* Initialise a GPIO controller
*
* @v gpios GPIO controller
* @v op GPIO operations
*/
static inline __attribute__ (( always_inline )) void
gpios_init ( struct gpios *gpios, struct gpio_operations *op ) {
gpios->op = op;
}
/**
* Stop using a GPIO controller
*
* @v gpios GPIO controller
*
* Drivers should call this method immediately before the final call
* to gpios_put().
*/
static inline __attribute__ (( always_inline )) void
gpios_nullify ( struct gpios *gpios ) {
gpios->op = &null_gpio_operations;
}
/**
* Get current GPIO input value
*
* @v gpio GPIO pin
* @ret active Pin is in the active state
*/
static inline int gpio_in ( struct gpio *gpio ) {
struct gpios *gpios = gpio->gpios;
return gpios->op->in ( gpios, gpio );
}
/**
* Set current GPIO output value
*
* @v gpio GPIO pin
* @v active Set pin to active state
*/
static inline void gpio_out ( struct gpio *gpio, int active ) {
struct gpios *gpios = gpio->gpios;
gpios->op->out ( gpios, gpio, active );
}
/**
* Configure GPIO pin
*
* @v gpio GPIO pin
* @v config Configuration
* @ret rc Return status code
*/
static inline int gpio_config ( struct gpio *gpio, unsigned int config ) {
struct gpios *gpios = gpio->gpios;
return gpios->op->config ( gpios, gpio, config );
}
extern struct gpios * alloc_gpios ( unsigned int count, size_t priv_len );
extern int gpios_register ( struct gpios *gpios );
extern void gpios_unregister ( struct gpios *gpios );
extern struct gpios * gpios_find ( unsigned int bus_type,
unsigned int location );
#endif /* _IPXE_GPIO_H */