/******************************************************************************
 *
 *  $Id$
 *
 *  Copyright (C) 2006-2008  Florian Pose, Ingenieurgemeinschaft IgH
 *
 *  This file is part of the IgH EtherCAT Master.
 *
 *  The IgH EtherCAT Master is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU General Public License version 2, as
 *  published by the Free Software Foundation.
 *
 *  The IgH EtherCAT Master 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 the IgH EtherCAT Master; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 *
 *  ---
 *
 *  The license mentioned above concerns the source code only. Using the
 *  EtherCAT technology and brand is only permitted in compliance with the
 *  industrial property and similar rights of Beckhoff Automation GmbH.
 *
 *****************************************************************************/

#include <linux/module.h>
#include <linux/err.h>
#include <linux/termios.h>

#include "../../include/ecrt.h" // EtherCAT realtime interface
#include "../../include/ectty.h" // EtherCAT TTY interface

/*****************************************************************************/

// Optional features
#define PFX "ec_tty_example: "

/*****************************************************************************/

#define VendorIdBeckhoff 0x00000002
#define ProductCodeBeckhoffEL6002 0x17723052
#define Beckhoff_EL6002 VendorIdBeckhoff, ProductCodeBeckhoffEL6002

typedef enum {
    SER_REQUEST_INIT,
    SER_WAIT_FOR_INIT_RESPONSE,
    SER_READY
} serial_state_t;

typedef struct {
    struct list_head list;

    ec_tty_t *tty;
    ec_slave_config_t *sc;

    size_t max_tx_data_size;
    size_t max_rx_data_size;

    u8 *tx_data;
    u8 tx_data_size;

    serial_state_t state;

    u8 tx_request_toggle;
    u8 tx_accepted_toggle;

    u8 rx_request_toggle;
    u8 rx_accepted_toggle;

    u16 control;

    u32 off_ctrl;
    u32 off_tx;
    u32 off_status;
    u32 off_rx;
} el6002_t;

LIST_HEAD(handlers);
        
/*****************************************************************************/

/* Beckhoff EL6002
 * Vendor ID:       0x00000002
 * Product code:    0x17723052
 * Revision number: 0x00100000
 */

ec_pdo_entry_info_t el6002_pdo_entries[] = {
   {0x7001, 0x01, 16}, /* Ctrl */
   {0x7000, 0x11, 8}, /* Data Out 0 */
   {0x7000, 0x12, 8}, /* Data Out 1 */
   {0x7000, 0x13, 8}, /* Data Out 2 */
   {0x7000, 0x14, 8}, /* Data Out 3 */
   {0x7000, 0x15, 8}, /* Data Out 4 */
   {0x7000, 0x16, 8}, /* Data Out 5 */
   {0x7000, 0x17, 8}, /* Data Out 6 */
   {0x7000, 0x18, 8}, /* Data Out 7 */
   {0x7000, 0x19, 8}, /* Data Out 8 */
   {0x7000, 0x1a, 8}, /* Data Out 9 */
   {0x7000, 0x1b, 8}, /* Data Out 10 */
   {0x7000, 0x1c, 8}, /* Data Out 11 */
   {0x7000, 0x1d, 8}, /* Data Out 12 */
   {0x7000, 0x1e, 8}, /* Data Out 13 */
   {0x7000, 0x1f, 8}, /* Data Out 14 */
   {0x7000, 0x20, 8}, /* Data Out 15 */
   {0x7000, 0x21, 8}, /* Data Out 16 */
   {0x7000, 0x22, 8}, /* Data Out 17 */
   {0x7000, 0x23, 8}, /* Data Out 18 */
   {0x7000, 0x24, 8}, /* Data Out 19 */
   {0x7000, 0x25, 8}, /* Data Out 20 */
   {0x7000, 0x26, 8}, /* Data Out 21 */
   {0x7011, 0x01, 16}, /* Ctrl */
   {0x7010, 0x11, 8}, /* Data Out 0 */
   {0x7010, 0x12, 8}, /* Data Out 1 */
   {0x7010, 0x13, 8}, /* Data Out 2 */
   {0x7010, 0x14, 8}, /* Data Out 3 */
   {0x7010, 0x15, 8}, /* Data Out 4 */
   {0x7010, 0x16, 8}, /* Data Out 5 */
   {0x7010, 0x17, 8}, /* Data Out 6 */
   {0x7010, 0x18, 8}, /* Data Out 7 */
   {0x7010, 0x19, 8}, /* Data Out 8 */
   {0x7010, 0x1a, 8}, /* Data Out 9 */
   {0x7010, 0x1b, 8}, /* Data Out 10 */
   {0x7010, 0x1c, 8}, /* Data Out 11 */
   {0x7010, 0x1d, 8}, /* Data Out 12 */
   {0x7010, 0x1e, 8}, /* Data Out 13 */
   {0x7010, 0x1f, 8}, /* Data Out 14 */
   {0x7010, 0x20, 8}, /* Data Out 15 */
   {0x7010, 0x21, 8}, /* Data Out 16 */
   {0x7010, 0x22, 8}, /* Data Out 17 */
   {0x7010, 0x23, 8}, /* Data Out 18 */
   {0x7010, 0x24, 8}, /* Data Out 19 */
   {0x7010, 0x25, 8}, /* Data Out 20 */
   {0x7010, 0x26, 8}, /* Data Out 21 */
   {0x6001, 0x01, 16}, /* Status */
   {0x6000, 0x11, 8}, /* Data In 0 */
   {0x6000, 0x12, 8}, /* Data In 1 */
   {0x6000, 0x13, 8}, /* Data In 2 */
   {0x6000, 0x14, 8}, /* Data In 3 */
   {0x6000, 0x15, 8}, /* Data In 4 */
   {0x6000, 0x16, 8}, /* Data In 5 */
   {0x6000, 0x17, 8}, /* Data In 6 */
   {0x6000, 0x18, 8}, /* Data In 7 */
   {0x6000, 0x19, 8}, /* Data In 8 */
   {0x6000, 0x1a, 8}, /* Data In 9 */
   {0x6000, 0x1b, 8}, /* Data In 10 */
   {0x6000, 0x1c, 8}, /* Data In 11 */
   {0x6000, 0x1d, 8}, /* Data In 12 */
   {0x6000, 0x1e, 8}, /* Data In 13 */
   {0x6000, 0x1f, 8}, /* Data In 14 */
   {0x6000, 0x20, 8}, /* Data In 15 */
   {0x6000, 0x21, 8}, /* Data In 16 */
   {0x6000, 0x22, 8}, /* Data In 17 */
   {0x6000, 0x23, 8}, /* Data In 18 */
   {0x6000, 0x24, 8}, /* Data In 19 */
   {0x6000, 0x25, 8}, /* Data In 20 */
   {0x6000, 0x26, 8}, /* Data In 21 */
   {0x6011, 0x01, 16}, /* Status */
   {0x6010, 0x11, 8}, /* Data In 0 */
   {0x6010, 0x12, 8}, /* Data In 1 */
   {0x6010, 0x13, 8}, /* Data In 2 */
   {0x6010, 0x14, 8}, /* Data In 3 */
   {0x6010, 0x15, 8}, /* Data In 4 */
   {0x6010, 0x16, 8}, /* Data In 5 */
   {0x6010, 0x17, 8}, /* Data In 6 */
   {0x6010, 0x18, 8}, /* Data In 7 */
   {0x6010, 0x19, 8}, /* Data In 8 */
   {0x6010, 0x1a, 8}, /* Data In 9 */
   {0x6010, 0x1b, 8}, /* Data In 10 */
   {0x6010, 0x1c, 8}, /* Data In 11 */
   {0x6010, 0x1d, 8}, /* Data In 12 */
   {0x6010, 0x1e, 8}, /* Data In 13 */
   {0x6010, 0x1f, 8}, /* Data In 14 */
   {0x6010, 0x20, 8}, /* Data In 15 */
   {0x6010, 0x21, 8}, /* Data In 16 */
   {0x6010, 0x22, 8}, /* Data In 17 */
   {0x6010, 0x23, 8}, /* Data In 18 */
   {0x6010, 0x24, 8}, /* Data In 19 */
   {0x6010, 0x25, 8}, /* Data In 20 */
   {0x6010, 0x26, 8}, /* Data In 21 */
};

ec_pdo_info_t el6002_pdos[] = {
   {0x1604, 23, el6002_pdo_entries + 0}, /* COM RxPDO-Map Outputs Ch.1 */
   {0x1605, 23, el6002_pdo_entries + 23}, /* COM RxPDO-Map Outputs Ch.2 */
   {0x1a04, 23, el6002_pdo_entries + 46}, /* COM TxPDO-Map Inputs Ch.1 */
   {0x1a05, 23, el6002_pdo_entries + 69}, /* COM TxPDO-Map Inputs Ch.2 */
};

ec_sync_info_t el6002_syncs[] = {
   {0, EC_DIR_OUTPUT, 0, NULL, EC_WD_DISABLE},
   {1, EC_DIR_INPUT, 0, NULL, EC_WD_DISABLE},
   {2, EC_DIR_OUTPUT, 2, el6002_pdos + 0, EC_WD_DISABLE},
   {3, EC_DIR_INPUT, 2, el6002_pdos + 2, EC_WD_DISABLE},
   {0xff}
};

/****************************************************************************/

int el6002_cflag_changed(void *data, unsigned short cflag)
{
    el6002_t *ser = (el6002_t *) data;
    int cs = 0, stop, par;

    printk(KERN_INFO PFX "%s(data=%p, cflag=%x).\n", __func__, ser, cflag);

    switch (cflag & CSIZE) {
        case CS7:
            cs = 7;
            break;
        case CS8:
            cs = 8;
            break;
        default: /* CS5 or CS6 */
            return -EINVAL; // not supported
    }

    stop = (cflag & CSTOPB) ? 2 : 1;

    if (cflag & PARENB) {
        par = (cflag & PARODD) ? 1 : 2;
    } else {
        par = 0;
    }

    printk(KERN_INFO PFX "CS%u stopb=%u par=%i.\n", cs, stop, par);

    return 0;
}

/****************************************************************************/

int el6002_init(el6002_t *ser, ec_master_t *master, u16 position,
        ec_domain_t *domain)
{
    int ret = 0;

    ser->tty = ectty_create(el6002_cflag_changed, ser);
    if (IS_ERR(ser->tty)) {
        printk(KERN_ERR PFX "Failed to create tty.\n");
        ret = PTR_ERR(ser->tty);
        goto out_return;
    }

    ser->sc = NULL;
    ser->max_tx_data_size = 22;
    ser->max_rx_data_size = 22;
    ser->tx_data = NULL;
    ser->tx_data_size = 0;
    ser->state = SER_REQUEST_INIT;
    ser->tx_request_toggle = 0;
    ser->rx_accepted_toggle = 0;
    ser->control = 0x0000;
    ser->off_ctrl = 0;
    ser->off_tx = 0;
    ser->off_status = 0;
    ser->off_rx = 0;

    if (!(ser->sc = ecrt_master_slave_config(
                    master, 0, position, Beckhoff_EL6002))) {
        printk(KERN_ERR PFX "Failed to create slave configuration.\n");
        ret = -EBUSY;
        goto out_free_tty;
    }

    if (ecrt_slave_config_pdos(ser->sc, EC_END, el6002_syncs)) {
        printk(KERN_ERR PFX "Failed to configure PDOs.\n");
        ret = -ENOMEM;
        goto out_free_tty;
    }
    
    ret = ecrt_slave_config_reg_pdo_entry(
            ser->sc, 0x7001, 0x01, domain, NULL);
    if (ret < 0) {
        printk(KERN_ERR PFX "Failed to register PDO entry.\n");
        goto out_free_tty;
    }
    ser->off_ctrl = ret;

    ret = ecrt_slave_config_reg_pdo_entry(
            ser->sc, 0x7000, 0x11, domain, NULL);
    if (ret < 0) {
        printk(KERN_ERR PFX "Failed to register PDO entry.\n");
        goto out_free_tty;
    }
    ser->off_tx = ret;

    ret = ecrt_slave_config_reg_pdo_entry(
            ser->sc, 0x6001, 0x01, domain, NULL);
    if (ret < 0) {
        printk(KERN_ERR PFX "Failed to register PDO entry.\n");
        goto out_free_tty;
    }
    ser->off_status = ret;

    ret = ecrt_slave_config_reg_pdo_entry(
            ser->sc, 0x6000, 0x11, domain, NULL);
    if (ret < 0) {
        printk(KERN_ERR PFX "Failed to register PDO entry.\n");
        goto out_free_tty;
    }
    ser->off_rx = ret;

    if (ser->max_tx_data_size > 0) {
        ser->tx_data = kmalloc(ser->max_tx_data_size, GFP_KERNEL);
        if (ser->tx_data == NULL) {
            ret = -ENOMEM;
            goto out_free_tty;
        }
    }

    return 0;

out_free_tty:
    ectty_free(ser->tty);
out_return:
    return ret;
}

/****************************************************************************/

void el6002_clear(el6002_t *ser)
{
    ectty_free(ser->tty);
    if (ser->tx_data) {
        kfree(ser->tx_data);
    }
}

/****************************************************************************/

void el6002_run(el6002_t *ser, u8 *pd)
{
    u16 status = EC_READ_U16(pd + ser->off_status);
    u8 *rx_data = pd + ser->off_rx;
    uint8_t tx_accepted_toggle, rx_request_toggle;

    switch (ser->state) {
        case SER_READY:

            /* Send data */
            
            tx_accepted_toggle = status & 0x0001;
            if (tx_accepted_toggle != ser->tx_accepted_toggle) { // ready
                ser->tx_data_size =
                    ectty_tx_data(ser->tty, ser->tx_data, ser->max_tx_data_size);
                if (ser->tx_data_size) {
                    printk(KERN_INFO PFX "Sending %u bytes.\n", ser->tx_data_size);
                    ser->tx_request_toggle = !ser->tx_request_toggle;
                    ser->tx_accepted_toggle = tx_accepted_toggle;
                }
            }

            /* Receive data */

            rx_request_toggle = status & 0x0002;
            if (rx_request_toggle != ser->rx_request_toggle) {
                uint8_t rx_data_size = status >> 8;
                ser->rx_request_toggle = rx_request_toggle;
                printk(KERN_INFO PFX "Received %u bytes.\n", rx_data_size);
                ectty_rx_data(ser->tty, rx_data, rx_data_size);
                ser->rx_accepted_toggle = !ser->rx_accepted_toggle;
            }

            ser->control =
                ser->tx_request_toggle |
                ser->rx_accepted_toggle << 1 |
                ser->tx_data_size << 8;
            break;

        case SER_REQUEST_INIT:
            if (status & (1 << 2)) {
                ser->control = 0x0000;
                ser->state = SER_WAIT_FOR_INIT_RESPONSE;
            } else {
                ser->control = 1 << 2; // CW.2, request initialization
            }
            break;

        case SER_WAIT_FOR_INIT_RESPONSE:
            if (!(status & (1 << 2))) {
                printk(KERN_INFO PFX "Init successful.\n");
                ser->tx_accepted_toggle = 1;
                ser->control = 0x0000;
                ser->state = SER_READY;
            }
            break;
    }

    EC_WRITE_U16(pd + ser->off_ctrl, ser->control);
    memcpy(pd + ser->off_tx, ser->tx_data, ser->tx_data_size);
}

/*****************************************************************************/

void run_serial_devices(u8 *pd)
{
    el6002_t *ser;

    list_for_each_entry(ser, &handlers, list) {
        el6002_run(ser, pd);
    }
}

/*****************************************************************************/

int create_serial_devices(ec_master_t *master, ec_domain_t *domain)
{
    int i, ret;
    ec_master_info_t master_info;
    ec_slave_info_t slave_info;
    el6002_t *ser, *next;

    printk(KERN_INFO PFX "Registering serial devices...\n");

    ret = ecrt_master(master, &master_info);
    if (ret) {
        printk(KERN_ERR PFX "Failed to obtain master information.\n");
        goto out_return;
    }

    for (i = 0; i < master_info.slave_count; i++) {
        ret = ecrt_master_get_slave(master, i, &slave_info);
        if (ret) {
            printk(KERN_ERR PFX "Failed to obtain slave information.\n");
            goto out_free_handlers;
        }

        if (slave_info.vendor_id != VendorIdBeckhoff
                || slave_info.product_code != ProductCodeBeckhoffEL6002) {
            continue;
        }

        printk(KERN_INFO PFX "Creating handler for serial device"
                " at position %i\n", i);

        ser = kmalloc(sizeof(*ser), GFP_KERNEL);
        if (!ser) {
            printk(KERN_ERR PFX "Failed to allocate serial device object.\n");
            ret = -ENOMEM;
            goto out_free_handlers;
        }

        ret = el6002_init(ser, master, i, domain);
        if (ret) {
            printk(KERN_ERR PFX "Failed to init serial device object.\n");
            kfree(ser);
            goto out_free_handlers;
        }

        list_add_tail(&ser->list, &handlers);
    }


    printk(KERN_INFO PFX "Finished.\n");
    return 0;

out_free_handlers:
    list_for_each_entry_safe(ser, next, &handlers, list) {
        list_del(&ser->list);
        el6002_clear(ser);
        kfree(ser);
    }
out_return:
    return ret;
}

/*****************************************************************************/

void free_serial_devices(void)
{
    el6002_t *ser, *next;

    printk(KERN_INFO PFX "Cleaning up serial devices...\n");

    list_for_each_entry_safe(ser, next, &handlers, list) {
        list_del(&ser->list);
        el6002_clear(ser);
        kfree(ser);
    }

    printk(KERN_INFO PFX "Finished cleaning up serial devices.\n");
}

/*****************************************************************************/