source: mainline/uspace/lib/libdrv/generic/driver.c@ 2480e19

/*
 * Copyright (c) 2010 Lenka Trochtova
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/**
 * @defgroup libdrv generic device driver support.
 * @brief HelenOS generic device driver support.
 * @{
 */

/** @file
 */

#include <assert.h>
#include <ipc/services.h>
#include <ipc/ns.h>
#include <async.h>
#include <stdio.h>
#include <errno.h>
#include <bool.h>
#include <fibril_synch.h>
#include <stdlib.h>
#include <string.h>
#include <ctype.h>
#include <errno.h>

#include <devman.h>
#include <ipc/devman.h>
#include <ipc/driver.h>

#include "driver.h"

static driver_t *driver;
LIST_INITIALIZE(devices);
FIBRIL_MUTEX_INITIALIZE(devices_mutex);

static device_t * driver_create_device()
{
        device_t *dev = (device_t *)malloc(sizeof(device_t));
        if (NULL != dev) {
                memset(dev, 0, sizeof(device_t));
        }
        return dev;
}

static void add_to_devices_list(device_t *dev)
{
        fibril_mutex_lock(&devices_mutex);
        list_append(&dev->link, &devices);
        fibril_mutex_unlock(&devices_mutex);
}

static void remove_from_devices_list(device_t *dev)
{
        fibril_mutex_lock(&devices_mutex);
        list_append(&dev->link, &devices);
        fibril_mutex_unlock(&devices_mutex);
}

static device_t * driver_get_device(link_t *devices, device_handle_t handle)
{
        device_t *dev = NULL;
        
        fibril_mutex_lock(&devices_mutex);      
        link_t *link = devices->next;
        while (link != devices) {
                dev = list_get_instance(link, device_t, link);
                if (handle == dev->handle) {
                        fibril_mutex_unlock(&devices_mutex);
                        return dev;
                }
                link = link->next;
        }
        fibril_mutex_unlock(&devices_mutex);

        return NULL;
}

static void driver_add_device(ipc_callid_t iid, ipc_call_t *icall)
{
        // TODO device state - the driver may detect the device is not actually present 
        // (old non PnP devices) or is not working properly. 
        // We should send such information to device manager.
        
        ipcarg_t ret;
        device_handle_t dev_handle =  IPC_GET_ARG1(*icall);
        device_t *dev = driver_create_device();
        dev->handle = dev_handle;
        add_to_devices_list(dev);
        if (driver->driver_ops->add_device(dev)) {              
                printf("%s: new device with handle = %x was added.\n", driver->name, dev_handle);
                ret = 1;
        } else {
                printf("%s: failed to add a new device with handle = %x.\n", driver->name, dev_handle); 
                remove_from_devices_list(dev);
                // TODO delete device           
                ret = 0;
        }
        ipc_answer_1(iid, EOK, ret);
}

static void driver_connection_devman(ipc_callid_t iid, ipc_call_t *icall)
{
        /* Accept connection */
        ipc_answer_0(iid, EOK);

        bool cont = true;
        while (cont) {
                ipc_call_t call;
                ipc_callid_t callid = async_get_call(&call);

                switch (IPC_GET_METHOD(call)) {
                case IPC_M_PHONE_HUNGUP:
                        cont = false;
                        continue;
                case DRIVER_ADD_DEVICE:
                        driver_add_device(callid, &call);
                        break;
                default:
                        if (!(callid & IPC_CALLID_NOTIFICATION))
                                ipc_answer_0(callid, ENOENT);
                }
        }
}

/**
 * Generic client connection handler both for applications and drivers.
 *
 * @param drv true for driver client, false for other clients (applications, services etc.).
 */
static void driver_connection_gen(ipc_callid_t iid, ipc_call_t *icall, bool drv)
{
        // Answer the first IPC_M_CONNECT_ME_TO call and remember the handle of the device to which the client connected.
        device_handle_t handle = IPC_GET_ARG2(*icall);
        device_t *dev = driver_get_device(&devices, handle);

        if (dev == NULL) {
                printf("%s: driver_connection_gen error - no device with handle %x was found.\n", driver->name, handle);
                ipc_answer_0(iid, ENOENT);
                return;
        }
        
        
        // TODO - if the client is not a driver, check whether it is allowed to use the device

        // TODO open the device (introduce some callbacks for opening and closing devices registered by the driver)
        
        ipc_answer_0(iid, EOK); 

        while (1) {
                ipc_callid_t callid;
                ipc_call_t call;
                callid = async_get_call(&call);
                ipcarg_t method = IPC_GET_METHOD(call);
                switch  (method) {
                case IPC_M_PHONE_HUNGUP:
                
                        // TODO close the device
                        
                        ipc_answer_0(callid, EOK);
                        return;
                default:

                        if (!is_valid_iface_id(method)) {
                                // this is not device's interface
                                printf("%s: driver_connection_gen error - invalid interface id %x.", driver->name, method);
                                ipc_answer_0(callid, ENOTSUP);
                                break;
                        }

                        // calling one of the device's interfaces
                        
                        // get the device interface structure
                        void *iface = device_get_iface(dev, method);
                        if (NULL == iface) {
                                printf("%s: driver_connection_gen error - ", driver->name);
                                printf("device with handle %x has no interface with id %x.\n", handle, method);
                                ipc_answer_0(callid, ENOTSUP);
                                break;
                        }

                        // get the corresponding interface for remote request handling ("remote interface")
                        remote_iface_t* rem_iface = get_remote_iface(method);
                        assert(NULL != rem_iface);

                        // get the method of the remote interface
                        ipcarg_t iface_method_idx = IPC_GET_ARG1(call);
                        remote_iface_func_ptr_t iface_method_ptr = get_remote_method(rem_iface, iface_method_idx);
                        if (NULL == iface_method_ptr) {
                                // the interface has not such method
                                printf("%s: driver_connection_gen error - invalid interface method.", driver->name);
                                ipc_answer_0(callid, ENOTSUP);
                                break;
                        }
                        
                        // call the remote interface's method, which will receive parameters from the remote client
                        // and it will pass it to the corresponding local interface method associated with the device 
                        // by its driver
                        (*iface_method_ptr)(dev, iface, callid, &call);
                        break;
                }
        }
}

static void driver_connection_driver(ipc_callid_t iid, ipc_call_t *icall)
{
        driver_connection_gen(iid, icall, true);
}

static void driver_connection_client(ipc_callid_t iid, ipc_call_t *icall)
{
        driver_connection_gen(iid, icall, false);
}


/** Function for handling connections to device driver.
 *
 */
static void driver_connection(ipc_callid_t iid, ipc_call_t *icall)
{
        /* Select interface */
        switch ((ipcarg_t) (IPC_GET_ARG1(*icall))) {
        case DRIVER_DEVMAN:
                // handle PnP events from device manager
                driver_connection_devman(iid, icall);
                break;
        case DRIVER_DRIVER:
                // handle request from drivers of child devices
                driver_connection_driver(iid, icall);
                break;
        case DRIVER_CLIENT:
                // handle requests from client applications
                driver_connection_client(iid, icall);
                break;

        default:
                /* No such interface */
                ipc_answer_0(iid, ENOENT);
        }
}

bool child_device_register(device_t *child, device_t *parent)
{
        // printf("%s: child_device_register\n", driver->name);

        assert(NULL != child->name);

        add_to_devices_list(child);
        if (EOK == devman_child_device_register(child->name, &child->match_ids, parent->handle, &child->handle)) {
                return true;
        }
        remove_from_devices_list(child);        
        return false;
}

int driver_main(driver_t *drv)
{
        // remember the driver structure - driver_ops will be called by generic handler for incoming connections
        driver = drv;

        // register driver by device manager with generic handler for incoming connections
        devman_driver_register(driver->name, driver_connection);

        async_manager();

        // Never reached
        return 0;
}

/**
 * @}
 */