gpio.h File Reference

General purpose I/O. More...

#include <stdint.h>
#include <ipxe/list.h>
#include <ipxe/refcnt.h>
#include <ipxe/device.h>

Go to the source code of this file.

Data Structures
struct	gpio
	A GPIO pin. More...
struct	gpios
	A GPIO controller. More...
struct	gpio_operations
	GPIO operations. More...

Macros
#define	GPIO_CFG_ACTIVE_LOW   0x01
	GPIO is active low.
#define	GPIO_CFG_OUTPUT   0x0100
	GPIO is an output.

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)
static struct gpios *	gpios_get (struct gpios *gpios)
	Get reference to GPIO controller.
static void	gpios_put (struct gpios *gpios)
	Drop reference to GPIO controller.
static struct gpio *	gpio_get (struct gpio *gpio)
	Get reference to GPIO pin.
static void	gpio_put (struct gpio *gpio)
	Drop reference to GPIO ping.
static void	gpios_init (struct gpios *gpios, struct gpio_operations *op)
	Initialise a GPIO controller.
static void	gpios_nullify (struct gpios *gpios)
	Stop using a GPIO controller.
static int	gpio_in (struct gpio *gpio)
	Get current GPIO input value.
static void	gpio_out (struct gpio *gpio, int active)
	Set current GPIO output value.
static int	gpio_config (struct gpio *gpio, unsigned int config)
	Configure GPIO pin.
struct gpios *	alloc_gpios (unsigned int count, size_t priv_len)
	Allocate GPIO controller.
int	gpios_register (struct gpios *gpios)
	Register GPIO controller.
void	gpios_unregister (struct gpios *gpios)
	Unregister GPIO controller.
struct gpios *	gpios_find (unsigned int bus_type, unsigned int location)
	Find GPIO controller.

Variables
struct gpio_operations	null_gpio_operations
	Null GPIO operations.

Detailed Description

General purpose I/O.

Definition in file gpio.h.

Macro Definition Documentation

GPIO_CFG_ACTIVE_LOW

#define GPIO_CFG_ACTIVE_LOW   0x01

GPIO is active low.

This bit is chosen to match the devicetree standard usage.

Definition at line 31 of file gpio.h.

GPIO_CFG_OUTPUT

#define GPIO_CFG_OUTPUT   0x0100

GPIO is an output.

Definition at line 34 of file gpio.h.

Referenced by dwgpio_config().

Function Documentation

FILE_LICENCE()

FILE_LICENCE

(

GPL2_OR_LATER_OR_UBDL

)

gpios_get()

struct gpios * gpios_get ( struct gpios * gpios )

inlinestatic

Get reference to GPIO controller.

Parameters

gpios

GPIO controller

Return values

gpios

GPIO controller

Definition at line 95 of file gpio.h.

                                  {
        ref_get ( &gpios->refcnt );
        return gpios;
}

References ref_get, and gpios::refcnt.

Referenced by gpio_get(), and gpios_register().

gpios_put()

void gpios_put ( struct gpios * gpios )

inlinestatic

Drop reference to GPIO controller.

Parameters

gpios

GPIO controller

Definition at line 106 of file gpio.h.

                                  {
        ref_put ( &gpios->refcnt );
}

References ref_put, and gpios::refcnt.

Referenced by dwgpio_probe(), dwgpio_remove(), gpio_put(), and gpios_unregister().

gpio_get()

struct gpio * gpio_get ( struct gpio * gpio )

inlinestatic

Get reference to GPIO pin.

Parameters

gpio

GPIO pin

Return values

gpio

GPIO pin

Definition at line 117 of file gpio.h.

                               {
        gpios_get ( gpio->gpios );
        return gpio;
}

References gpio::gpios, and gpios_get().

gpio_put()

void gpio_put ( struct gpio * gpio )

inlinestatic

Drop reference to GPIO ping.

Parameters

gpio

GPIO pin

Definition at line 128 of file gpio.h.

                               {
        gpios_put ( gpio->gpios );
}

References gpio::gpios, and gpios_put().

gpios_init()

void gpios_init ( struct gpios * gpios, struct gpio_operations * op )

inlinestatic

Initialise a GPIO controller.

Parameters

gpios	GPIO controller
op	GPIO operations

Definition at line 139 of file gpio.h.

                                                               {
        gpios->op = op;
}

References gpios::op, and op.

Referenced by dwgpio_probe().

gpios_nullify()

void gpios_nullify ( struct gpios * gpios )

inlinestatic

Stop using a GPIO controller.

Parameters

gpios

GPIO controller

Drivers should call this method immediately before the final call to gpios_put().

Definition at line 152 of file gpio.h.

                                      {
        gpios->op = &null_gpio_operations;
}

References null_gpio_operations, and gpios::op.

Referenced by dwgpio_probe(), and dwgpio_remove().

gpio_in()

int gpio_in ( struct gpio * gpio )

inlinestatic

Get current GPIO input value.

Parameters

gpio

GPIO pin

Return values

active

Pin is in the active state

Definition at line 162 of file gpio.h.

                                                {
        struct gpios *gpios = gpio->gpios;
 
        return gpios->op->in ( gpios, gpio );
}

References gpio::gpios, gpio_operations::in, and gpios::op.

gpio_out()

void gpio_out ( struct gpio * gpio, int active )

inlinestatic

Set current GPIO output value.

Parameters

gpio	GPIO pin
active	Set pin to active state

Definition at line 174 of file gpio.h.

                                                              {
        struct gpios *gpios = gpio->gpios;
 
        gpios->op->out ( gpios, gpio, active );
}

References gpio::gpios, gpios::op, and gpio_operations::out.

gpio_config()

int gpio_config ( struct gpio * gpio, unsigned int config )

inlinestatic

Configure GPIO pin.

Parameters

gpio	GPIO pin
config	Configuration

Return values

rc	Return status code

Definition at line 187 of file gpio.h.

                                                                         {
        struct gpios *gpios = gpio->gpios;
 
        return gpios->op->config ( gpios, gpio, config );
}

References gpio_operations::config, gpio::gpios, and gpios::op.

alloc_gpios()

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

extern

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

Referenced by dwgpio_probe().

gpios_register()

int gpios_register ( struct gpios * gpios )

extern

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 )

extern

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 )

extern

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.

Variable Documentation

null_gpio_operations

struct gpio_operations null_gpio_operations

extern

Null GPIO operations.

Definition at line 161 of file gpio.c.

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

Referenced by gpios_nullify().