--- /dev/null
+/*
+ * 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,
+};
#define ERRFILE_efi_open ( ERRFILE_CORE | 0x002f0000 )
#define ERRFILE_efi_table ( ERRFILE_CORE | 0x00300000 )
#define ERRFILE_efi_connect ( ERRFILE_CORE | 0x00310000 )
+#define ERRFILE_gpio ( ERRFILE_CORE | 0x00320000 )
#define ERRFILE_eisa ( ERRFILE_DRIVER | 0x00000000 )
#define ERRFILE_isa ( ERRFILE_DRIVER | 0x00010000 )
--- /dev/null
+#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 */
projects / thirdparty / ipxe.git / commitdiff
