source: mainline/uspace/lib/drv/generic/driver.c@ c47e1a8

/*
 * 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 <str.h>
#include <ctype.h>
#include <errno.h>

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

#include "driver.h"

// driver structure 

static driver_t *driver;

// devices

LIST_INITIALIZE(devices);
FIBRIL_MUTEX_INITIALIZE(devices_mutex);

// interrupts 

static interrupt_context_list_t interrupt_contexts;

static irq_cmd_t default_cmds[] = {
        {
                .cmd = CMD_ACCEPT
        }
};

static irq_code_t default_pseudocode = {
        sizeof(default_cmds) / sizeof(irq_cmd_t),
        default_cmds
};


static void driver_irq_handler(ipc_callid_t iid, ipc_call_t *icall)
{       
        int id = (int)IPC_GET_METHOD(*icall);
        interrupt_context_t *ctx = find_interrupt_context_by_id(&interrupt_contexts, id);
        if (NULL != ctx && NULL != ctx->handler) {
                (*ctx->handler)(ctx->dev, iid, icall);          
        }
}

/** Wrapper for receiving strings
 *
 * This wrapper only makes it more comfortable to use async_data_write_*
 * functions to receive strings.
 *
 * @param str      Pointer to string pointer (which should be later disposed
 *                 by free()). If the operation fails, the pointer is not
 *                 touched.
 * @param max_size Maximum size (in bytes) of the string to receive. 0 means
 *                 no limit.
 * @param received If not NULL, the size of the received data is stored here.
 *
 * @return Zero on success or a value from @ref errno.h on failure.
 *
 */
static int async_string_receive(char **str, const size_t max_size, size_t *received)
{
        ipc_callid_t callid;
        size_t size;
        if (!async_data_write_receive(&callid, &size)) {
                ipc_answer_0(callid, EINVAL);
                return EINVAL;
        }
        
        if ((max_size > 0) && (size > max_size)) {
                ipc_answer_0(callid, EINVAL);
                return EINVAL;
        }
        
        char *data = (char *) malloc(size + 1);
        if (data == NULL) {
                ipc_answer_0(callid, ENOMEM);
                return ENOMEM;
        }
        
        int rc = async_data_write_finalize(callid, data, size);
        if (rc != EOK) {
                free(data);
                return rc;
        }
        
        data[size] = 0;
        *str = data;
        if (received != NULL)
                *received = size;
        
        return EOK;
}

int register_interrupt_handler(device_t *dev, int irq, interrupt_handler_t *handler, irq_code_t *pseudocode)
{
        interrupt_context_t *ctx = create_interrupt_context();
        
        ctx->dev = dev;
        ctx->irq = irq;
        ctx->handler = handler;
        
        add_interrupt_context(&interrupt_contexts, ctx);
        
        if (NULL == pseudocode) {
                pseudocode = &default_pseudocode;
        }
        
        int res = ipc_register_irq(irq, dev->handle, ctx->id, pseudocode);
        if (0 != res) {
                remove_interrupt_context(&interrupt_contexts, ctx);
                delete_interrupt_context(ctx);
        }
        return res;     
}

int unregister_interrupt_handler(device_t *dev, int irq)
{
        interrupt_context_t *ctx = find_interrupt_context(&interrupt_contexts, dev, irq);
        int res = ipc_unregister_irq(irq, dev->handle);
        if (NULL != ctx) {
                remove_interrupt_context(&interrupt_contexts, ctx);
                delete_interrupt_context(ctx);          
        }
        return res;
}

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_remove(&dev->link);
        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)
{
        char *dev_name = NULL;
        int res = EOK;
        
        device_handle_t dev_handle =  IPC_GET_ARG1(*icall);
        device_t *dev = create_device();
        dev->handle = dev_handle;
        
        async_string_receive(&dev_name, 0, NULL);
        dev->name = dev_name;
        
        add_to_devices_list(dev);               
        res = driver->driver_ops->add_device(dev);
        if (0 == res) {
                printf("%s: new device with handle = %x was added.\n", driver->name, dev_handle);
        } else {
                printf("%s: failed to add a new device with handle = %d.\n", driver->name, dev_handle); 
                remove_from_devices_list(dev);
                delete_device(dev);     
        }
        
        ipc_answer_0(iid, res);
}

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

        int ret = EOK;
        // open the device
        if (NULL != dev->class && NULL != dev->class->open) {
                ret = (*dev->class->open)(dev);
        }
        
        ipc_answer_0(iid, ret); 

        while (1) {
                ipc_callid_t callid;
                ipc_call_t call;
                callid = async_get_call(&call);
                ipcarg_t method = IPC_GET_METHOD(call);
                int iface_idx;
                
                switch  (method) {
                case IPC_M_PHONE_HUNGUP:                
                        // close the device
                        if (NULL != dev->class && NULL != dev->class->close) {
                                (*dev->class->close)(dev);
                        }                       
                        ipc_answer_0(callid, EOK);
                        return;
                default:                
                        // convert ipc interface id to interface index
                        
                        iface_idx = DEV_IFACE_IDX(method);
                        
                        if (!is_valid_iface_idx(iface_idx)) {
                                remote_handler_t *default_handler;
                                if (NULL != (default_handler = device_get_default_handler(dev))) {
                                        (*default_handler)(dev, callid, &call);
                                        break;
                                }
                                // this is not device's interface and the default handler is not provided
                                printf("%s: driver_connection_gen error - invalid interface id %d.", driver->name, iface_idx);
                                ipc_answer_0(callid, ENOTSUP);
                                break;
                        }

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

                        // get the corresponding interface for remote request handling ("remote interface")
                        remote_iface_t* rem_iface = get_remote_iface(iface_idx);
                        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);
        }
}

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

        assert(NULL != child->name);

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

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

        // initialize the list of interrupt contexts
        init_interrupt_context_list(&interrupt_contexts);
        
        // set generic interrupt handler
        async_set_interrupt_received(driver_irq_handler);
        
        // register driver by device manager with generic handler for incoming connections
        devman_driver_register(driver->name, driver_connection);

        async_manager();

        // Never reached
        return 0;
}

/**
 * @}
 */