/*********************************************************************
 *
 * Filename:      ircomm_param.c
 * Version:       1.0
 * Description:   Parameter handling for the IrCOMM protocol
 * Status:        Experimental.
 * Author:        Dag Brattli <dagb@cs.uit.no>
 * Created at:    Mon Jun  7 10:25:11 1999
 * Modified at:   Sun Jan 30 14:32:03 2000
 * Modified by:   Dag Brattli <dagb@cs.uit.no>
 *
 *     Copyright (c) 1999-2000 Dag Brattli, All Rights Reserved.
 *
 *     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, see <http://www.gnu.org/licenses/>.
 *
 ********************************************************************/

#include <linux/gfp.h>
#include <linux/workqueue.h>
#include <linux/interrupt.h>

#include <net/irda/irda.h>
#include <net/irda/parameters.h>

#include <net/irda/ircomm_core.h>
#include <net/irda/ircomm_tty_attach.h>
#include <net/irda/ircomm_tty.h>

#include <net/irda/ircomm_param.h>

static int ircomm_param_service_type(void *instance, irda_param_t *param,
				     int get);
static int ircomm_param_port_type(void *instance, irda_param_t *param,
				  int get);
static int ircomm_param_port_name(void *instance, irda_param_t *param,
				  int get);
static int ircomm_param_service_type(void *instance, irda_param_t *param,
				     int get);
static int ircomm_param_data_rate(void *instance, irda_param_t *param,
				  int get);
static int ircomm_param_data_format(void *instance, irda_param_t *param,
				    int get);
static int ircomm_param_flow_control(void *instance, irda_param_t *param,
				     int get);
static int ircomm_param_xon_xoff(void *instance, irda_param_t *param, int get);
static int ircomm_param_enq_ack(void *instance, irda_param_t *param, int get);
static int ircomm_param_line_status(void *instance, irda_param_t *param,
				    int get);
static int ircomm_param_dte(void *instance, irda_param_t *param, int get);
static int ircomm_param_dce(void *instance, irda_param_t *param, int get);
static int ircomm_param_poll(void *instance, irda_param_t *param, int get);

static const pi_minor_info_t pi_minor_call_table_common[] = {
	{ ircomm_param_service_type, PV_INT_8_BITS },
	{ ircomm_param_port_type,    PV_INT_8_BITS },
	{ ircomm_param_port_name,    PV_STRING }
};
static const pi_minor_info_t pi_minor_call_table_non_raw[] = {
	{ ircomm_param_data_rate,    PV_INT_32_BITS | PV_BIG_ENDIAN },
	{ ircomm_param_data_format,  PV_INT_8_BITS },
	{ ircomm_param_flow_control, PV_INT_8_BITS },
	{ ircomm_param_xon_xoff,     PV_INT_16_BITS },
	{ ircomm_param_enq_ack,      PV_INT_16_BITS },
	{ ircomm_param_line_status,  PV_INT_8_BITS }
};
static const pi_minor_info_t pi_minor_call_table_9_wire[] = {
	{ ircomm_param_dte,          PV_INT_8_BITS },
	{ ircomm_param_dce,          PV_INT_8_BITS },
	{ ircomm_param_poll,         PV_NO_VALUE },
};

static const pi_major_info_t pi_major_call_table[] = {
	{ pi_minor_call_table_common,  3 },
	{ pi_minor_call_table_non_raw, 6 },
	{ pi_minor_call_table_9_wire,  3 }
/* 	{ pi_minor_call_table_centronics }  */
};

pi_param_info_t ircomm_param_info = { pi_major_call_table, 3, 0x0f, 4 };

/*
 * Function ircomm_param_request (self, pi, flush)
 *
 *    Queue a parameter for the control channel
 *
 */
int ircomm_param_request(struct ircomm_tty_cb *self, __u8 pi, int flush)
{
	unsigned long flags;
	struct sk_buff *skb;
	int count;

	IRDA_ASSERT(self != NULL, return -1;);
	IRDA_ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	/* Make sure we don't send parameters for raw mode */
	if (self->service_type == IRCOMM_3_WIRE_RAW)
		return 0;

	spin_lock_irqsave(&self->spinlock, flags);

	skb = self->ctrl_skb;
	if (!skb) {
		skb = alloc_skb(256, GFP_ATOMIC);
		if (!skb) {
			spin_unlock_irqrestore(&self->spinlock, flags);
			return -ENOMEM;
		}

		skb_reserve(skb, self->max_header_size);
		self->ctrl_skb = skb;
	}
	/*
	 * Inserting is a little bit tricky since we don't know how much
	 * room we will need. But this should hopefully work OK
	 */
	count = irda_param_insert(self, pi, skb_tail_pointer(skb),
				  skb_tailroom(skb), &ircomm_param_info);
	if (count < 0) {
		net_warn_ratelimited("%s(), no room for parameter!\n",
				     __func__);
		spin_unlock_irqrestore(&self->spinlock, flags);
		return -1;
	}
	skb_put(skb, count);
	pr_debug("%s(), skb->len=%d\n", __func__, skb->len);

	spin_unlock_irqrestore(&self->spinlock, flags);

	if (flush) {
		/* ircomm_tty_do_softint will take care of the rest */
		schedule_work(&self->tqueue);
	}

	return count;
}

/*
 * Function ircomm_param_service_type (self, buf, len)
 *
 *    Handle service type, this function will both be called after the LM-IAS
 *    query and then the remote device sends its initial parameters
 *
 */
static int ircomm_param_service_type(void *instance, irda_param_t *param,
				     int get)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) instance;
	__u8 service_type = (__u8) param->pv.i;

	IRDA_ASSERT(self != NULL, return -1;);
	IRDA_ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	if (get) {
		param->pv.i = self->settings.service_type;
		return 0;
	}

	/* Find all common service types */
	service_type &= self->service_type;
	if (!service_type) {
		pr_debug("%s(), No common service type to use!\n", __func__);
		return -1;
	}
	pr_debug("%s(), services in common=%02x\n", __func__ ,
		 service_type);

	/*
	 * Now choose a preferred service type of those available
	 */
	if (service_type & IRCOMM_CENTRONICS)
		self->settings.service_type = IRCOMM_CENTRONICS;
	else if (service_type & IRCOMM_9_WIRE)
		self->settings.service_type = IRCOMM_9_WIRE;
	else if (service_type & IRCOMM_3_WIRE)
		self->settings.service_type = IRCOMM_3_WIRE;
	else if (service_type & IRCOMM_3_WIRE_RAW)
		self->settings.service_type = IRCOMM_3_WIRE_RAW;

	pr_debug("%s(), resulting service type=0x%02x\n", __func__ ,
		 self->settings.service_type);

	/*
	 * Now the line is ready for some communication. Check if we are a
	 * server, and send over some initial parameters.
	 * Client do it in ircomm_tty_state_setup().
	 * Note : we may get called from ircomm_tty_getvalue_confirm(),
	 * therefore before we even have open any socket. And self->client
	 * is initialised to TRUE only later. So, we check if the link is
	 * really initialised. - Jean II
	 */
	if ((self->max_header_size != IRCOMM_TTY_HDR_UNINITIALISED) &&
	    (!self->client) &&
	    (self->settings.service_type != IRCOMM_3_WIRE_RAW))
	{
		/* Init connection */
		ircomm_tty_send_initial_parameters(self);
		ircomm_tty_link_established(self);
	}

	return 0;
}

/*
 * Function ircomm_param_port_type (self, param)
 *
 *    The port type parameter tells if the devices are serial or parallel.
 *    Since we only advertise serial service, this parameter should only
 *    be equal to IRCOMM_SERIAL.
 */
static int ircomm_param_port_type(void *instance, irda_param_t *param, int get)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) instance;

	IRDA_ASSERT(self != NULL, return -1;);
	IRDA_ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	if (get)
		param->pv.i = IRCOMM_SERIAL;
	else {
		self->settings.port_type = (__u8) param->pv.i;

		pr_debug("%s(), port type=%d\n", __func__ ,
			 self->settings.port_type);
	}
	return 0;
}

/*
 * Function ircomm_param_port_name (self, param)
 *
 *    Exchange port name
 *
 */
static int ircomm_param_port_name(void *instance, irda_param_t *param, int get)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) instance;

	IRDA_ASSERT(self != NULL, return -1;);
	IRDA_ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	if (get) {
		pr_debug("%s(), not imp!\n", __func__);
	} else {
		pr_debug("%s(), port-name=%s\n", __func__ , param->pv.c);
		strncpy(self->settings.port_name, param->pv.c, 32);
	}

	return 0;
}

/*
 * Function ircomm_param_data_rate (self, param)
 *
 *    Exchange data rate to be used in this settings
 *
 */
static int ircomm_param_data_rate(void *instance, irda_param_t *param, int get)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) instance;

	IRDA_ASSERT(self != NULL, return -1;);
	IRDA_ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	if (get)
		param->pv.i = self->settings.data_rate;
	else
		self->settings.data_rate = param->pv.i;

	pr_debug("%s(), data rate = %d\n", __func__ , param->pv.i);

	return 0;
}

/*
 * Function ircomm_param_data_format (self, param)
 *
 *    Exchange data format to be used in this settings
 *
 */
static int ircomm_param_data_format(void *instance, irda_param_t *param,
				    int get)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) instance;

	IRDA_ASSERT(self != NULL, return -1;);
	IRDA_ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	if (get)
		param->pv.i = self->settings.data_format;
	else
		self->settings.data_format = (__u8) param->pv.i;

	return 0;
}

/*
 * Function ircomm_param_flow_control (self, param)
 *
 *    Exchange flow control settings to be used in this settings
 *
 */
static int ircomm_param_flow_control(void *instance, irda_param_t *param,
				     int get)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) instance;

	IRDA_ASSERT(self != NULL, return -1;);
	IRDA_ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	if (get)
		param->pv.i = self->settings.flow_control;
	else
		self->settings.flow_control = (__u8) param->pv.i;

	pr_debug("%s(), flow control = 0x%02x\n", __func__ , (__u8)param->pv.i);

	return 0;
}

/*
 * Function ircomm_param_xon_xoff (self, param)
 *
 *    Exchange XON/XOFF characters
 *
 */
static int ircomm_param_xon_xoff(void *instance, irda_param_t *param, int get)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) instance;

	IRDA_ASSERT(self != NULL, return -1;);
	IRDA_ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	if (get) {
		param->pv.i = self->settings.xonxoff[0];
		param->pv.i |= self->settings.xonxoff[1] << 8;
	} else {
		self->settings.xonxoff[0] = (__u16) param->pv.i & 0xff;
		self->settings.xonxoff[1] = (__u16) param->pv.i >> 8;
	}

	pr_debug("%s(), XON/XOFF = 0x%02x,0x%02x\n", __func__ ,
		 param->pv.i & 0xff, param->pv.i >> 8);

	return 0;
}

/*
 * Function ircomm_param_enq_ack (self, param)
 *
 *    Exchange ENQ/ACK characters
 *
 */
static int ircomm_param_enq_ack(void *instance, irda_param_t *param, int get)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) instance;

	IRDA_ASSERT(self != NULL, return -1;);
	IRDA_ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	if (get) {
		param->pv.i = self->settings.enqack[0];
		param->pv.i |= self->settings.enqack[1] << 8;
	} else {
		self->settings.enqack[0] = (__u16) param->pv.i & 0xff;
		self->settings.enqack[1] = (__u16) param->pv.i >> 8;
	}

	pr_debug("%s(), ENQ/ACK = 0x%02x,0x%02x\n", __func__ ,
		 param->pv.i & 0xff, param->pv.i >> 8);

	return 0;
}

/*
 * Function ircomm_param_line_status (self, param)
 *
 *
 *
 */
static int ircomm_param_line_status(void *instance, irda_param_t *param,
				    int get)
{
	pr_debug("%s(), not impl.\n", __func__);

	return 0;
}

/*
 * Function ircomm_param_dte (instance, param)
 *
 *    If we get here, there must be some sort of null-modem connection, and
 *    we are probably working in server mode as well.
 */
static int ircomm_param_dte(void *instance, irda_param_t *param, int get)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) instance;
	__u8 dte;

	IRDA_ASSERT(self != NULL, return -1;);
	IRDA_ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	if (get)
		param->pv.i = self->settings.dte;
	else {
		dte = (__u8) param->pv.i;

		self->settings.dce = 0;

		if (dte & IRCOMM_DELTA_DTR)
			self->settings.dce |= (IRCOMM_DELTA_DSR|
					      IRCOMM_DELTA_RI |
					      IRCOMM_DELTA_CD);
		if (dte & IRCOMM_DTR)
			self->settings.dce |= (IRCOMM_DSR|
					      IRCOMM_RI |
					      IRCOMM_CD);

		if (dte & IRCOMM_DELTA_RTS)
			self->settings.dce |= IRCOMM_DELTA_CTS;
		if (dte & IRCOMM_RTS)
			self->settings.dce |= IRCOMM_CTS;

		/* Take appropriate actions */
		ircomm_tty_check_modem_status(self);

		/* Null modem cable emulator */
		self->settings.null_modem = TRUE;
	}

	return 0;
}

/*
 * Function ircomm_param_dce (instance, param)
 *
 *
 *
 */
static int ircomm_param_dce(void *instance, irda_param_t *param, int get)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) instance;
	__u8 dce;

	pr_debug("%s(), dce = 0x%02x\n", __func__ , (__u8)param->pv.i);

	dce = (__u8) param->pv.i;

	IRDA_ASSERT(self != NULL, return -1;);
	IRDA_ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	self->settings.dce = dce;

	/* Check if any of the settings have changed */
	if (dce & 0x0f) {
		if (dce & IRCOMM_DELTA_CTS) {
			pr_debug("%s(), CTS\n", __func__);
		}
	}

	ircomm_tty_check_modem_status(self);

	return 0;
}

/*
 * Function ircomm_param_poll (instance, param)
 *
 *    Called when the peer device is polling for the line settings
 *
 */
static int ircomm_param_poll(void *instance, irda_param_t *param, int get)
{
	struct ircomm_tty_cb *self = (struct ircomm_tty_cb *) instance;

	IRDA_ASSERT(self != NULL, return -1;);
	IRDA_ASSERT(self->magic == IRCOMM_TTY_MAGIC, return -1;);

	/* Poll parameters are always of length 0 (just a signal) */
	if (!get) {
		/* Respond with DTE line settings */
		ircomm_param_request(self, IRCOMM_DTE, TRUE);
	}
	return 0;
}