General purpose I/O. More...

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

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. More...

#define	GPIO_CFG_OUTPUT 0x0100
	GPIO is an output. More...

Functions
	FILE_LICENCE (GPL2_OR_LATER_OR_UBDL)

static struct gpios *	gpios_get (struct gpios *gpios)
	Get reference to GPIO controller. More...

static void	gpios_put (struct gpios *gpios)
	Drop reference to GPIO controller. More...

static struct gpio *	gpio_get (struct gpio *gpio)
	Get reference to GPIO pin. More...

static void	gpio_put (struct gpio *gpio)
	Drop reference to GPIO ping. More...

static void	gpios_init (struct gpios gpios, struct gpio_operations op)
	Initialise a GPIO controller. More...

static void	gpios_nullify (struct gpios *gpios)
	Stop using a GPIO controller. More...

static int	gpio_in (struct gpio *gpio)
	Get current GPIO input value. More...

static void	gpio_out (struct gpio *gpio, int active)
	Set current GPIO output value. More...

static int	gpio_config (struct gpio *gpio, unsigned int config)
	Configure GPIO pin. 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...

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

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.

Function Documentation

◆ FILE_LICENCE()

FILE_LICENCE ( GPL2_OR_LATER_OR_UBDL )

◆ gpios_get()

static 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()

static 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()

static 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, gpio::gpios, and gpios_get().

◆ gpio_put()

static 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()

static 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()

static 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()

static 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()

static 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()

static 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
	)

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.

Variable Documentation

◆ null_gpio_operations

struct gpio_operations null_gpio_operations

Null GPIO operations.

Definition at line 161 of file gpio.c.

Referenced by gpios_nullify().

Data Structures

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

◆ GPIO_CFG_ACTIVE_LOW

◆ GPIO_CFG_OUTPUT

Function Documentation

◆ FILE_LICENCE()

◆ gpios_get()

◆ gpios_put()

◆ gpio_get()

◆ gpio_put()

◆ gpios_init()

◆ gpios_nullify()

◆ gpio_in()

◆ gpio_out()

◆ gpio_config()

◆ alloc_gpios()

◆ gpios_register()

◆ gpios_unregister()

◆ gpios_find()

Variable Documentation

◆ null_gpio_operations