gpio.c File Reference

General purpose I/O. More...

#include <stdlib.h>
#include <errno.h>
#include <ipxe/gpio.h>

Go to the source code of this file.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
static	LIST_HEAD (all_gpios)
	List of GPIO controllers. More...
struct gpios *	alloc_gpios (unsigned int count, size_t priv_len)
	Allocate GPIO controller. More...
int	gpios_register (struct gpios *gpios)
	Register GPIO controller. More...
void	gpios_unregister (struct gpios *gpios)
	Unregister GPIO controller. More...
struct gpios *	gpios_find (unsigned int bus_type, unsigned int location)
	Find GPIO controller. More...
static int	null_gpio_in (struct gpios *gpios __unused, struct gpio *gpio __unused)
	Get null GPIO input value. More...
static void	null_gpio_out (struct gpios *gpios __unused, struct gpio *gpio __unused, int active __unused)
	Set null GPIO output value. More...
static int	null_gpio_config (struct gpios *gpios __unused, struct gpio *gpio __unused, unsigned int config __unused)
	Configure null GPIO pin. More...

Variables
struct gpio_operations	null_gpio_operations
	Null GPIO operations. More...

Detailed Description

General purpose I/O.

Definition in file gpio.c.

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

LIST_HEAD()

static LIST_HEAD ( all_gpios  )

static

List of GPIO controllers.

alloc_gpios()

struct gpios* alloc_gpios	(	unsigned int	count,
		size_t	priv_len
	)

Allocate GPIO controller.

Parameters

count	Number of GPIO pins
priv_len	Size of driver-private data

Return values

gpios

GPIO controller, or NULL

Definition at line 46 of file gpio.c.

                                                                   {
        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;
}

References gpios::count, count, gpio, gpios::gpio, gpio::gpios, gpio::index, len, NULL, gpios::priv, and zalloc().

Referenced by dwgpio_probe().

gpios_register()

int gpios_register

(

struct gpios *

gpios

)

Register GPIO controller.

Parameters

gpios

GPIO controller

Return values

rc	Return status code

Definition at line 78 of file gpio.c.

                                           {

        /* 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;
}

References gpios::count, DBGC, gpios::dev, gpios_get(), gpios::list, list_add_tail, and device::name.

Referenced by dwgpio_probe().

gpios_unregister()

void gpios_unregister

(

struct gpios *

gpios

)

Unregister GPIO controller.

Parameters

gpios

GPIO controller

Definition at line 94 of file gpio.c.

                                              {

        /* Remove from list of GPIO controllers */
        DBGC ( gpios, "GPIO %s unregistered\n", gpios->dev->name );
        list_del ( &gpios->list );
        gpios_put ( gpios );
}

References DBGC, gpios::dev, gpios_put(), gpios::list, list_del, and device::name.

Referenced by dwgpio_probe(), and dwgpio_remove().

gpios_find()

struct gpios* gpios_find	(	unsigned int	bus_type,
		unsigned int	location
	)

Find GPIO controller.

Parameters

bus_type	Bus type
location	Bus location

Return values

gpios

GPIO controller, or NULL

Definition at line 109 of file gpio.c.

                                                                           {
        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;
}

References device_description::bus_type, device::desc, gpios::dev, gpios::list, list_for_each_entry, device_description::location, and NULL.

null_gpio_in()

static int null_gpio_in ( struct gpios *gpios  __unused, struct gpio *gpio  __unused  )

static

Get null GPIO input value.

Parameters

gpios	GPIO controller
gpio	GPIO pin

Return values

active

Pin is in the active state

Definition at line 129 of file gpio.c.

                                                       {
        return 0;
}

null_gpio_out()

static void null_gpio_out ( struct gpios *gpios  __unused, struct gpio *gpio  __unused, int active  __unused  )

static

Set null GPIO output value.

Parameters

gpios	GPIO controller
gpio	GPIO pin
active	Set pin to active state

Definition at line 141 of file gpio.c.

                                                                              {
        /* Nothing to do */
}

null_gpio_config()

static int null_gpio_config ( struct gpios *gpios  __unused, struct gpio *gpio  __unused, unsigned int config  __unused  )

static

Configure null GPIO pin.

Parameters

gpios	GPIO controller
gpio	GPIO pin
config	Configuration

Return values

rc	Return status code

Definition at line 154 of file gpio.c.

                                                             {
        return -ENODEV;
}

References ENODEV.

Variable Documentation

null_gpio_operations

struct gpio_operations null_gpio_operations

Initial value:

= {
        .in = null_gpio_in,
        .out = null_gpio_out,
        .config = null_gpio_config,
}

Null GPIO operations.

Definition at line 161 of file gpio.c.

Referenced by gpios_nullify().