/*
 * IBM ASM Service Processor Device Driver
 *
 * 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
 *
 * Copyright (C) IBM Corporation, 2004
 *
 * Author: Max Asböck <amax@us.ibm.com> 
 *
 */

#include <linux/kernel.h>
#include <linux/types.h>
#include <linux/errno.h>
#include <linux/list.h>
#include <linux/wait.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/config.h>
#include <linux/module.h>
#include <linux/version.h>
#include <linux/interrupt.h>
#include <linux/device.h>

/* Driver identification */
#define DRIVER_NAME	"ibmasm"
#define DRIVER_VERSION  "0.4"
#define DRIVER_AUTHOR   "Max Asbock"
#define DRIVER_DESC     "IBM ASM Service Processor Driver"

#define err(msg) printk(KERN_ERR "%s: " msg "\n", DRIVER_NAME)
#define info(msg) printk(KERN_INFO "%s: " msg "\n", DRIVER_NAME)


#define IBMASM_CMD_PENDING	0	
#define IBMASM_CMD_COMPLETE	1	
#define IBMASM_CMD_FAILED	2

#define IBMASM_CMD_TIMEOUT_NORMAL	45
#define IBMASM_CMD_TIMEOUT_EXTRA	240

#define IBMASM_CMD_MAX_BUFFER_SIZE	0x4000

#define REVERSE_HEARTBEAT_TIMEOUT	120

#define HEARTBEAT_BUFFER_SIZE		0x400

#ifdef IA64
#define IBMASM_DRIVER_VPD "Lin64 6.08      "
#else
#define IBMASM_DRIVER_VPD "Lin32 6.08      "
#endif

#define SYSTEM_STATE_OS_UP      5
#define SYSTEM_STATE_OS_DOWN    4

#define IBMASM_NAME_SIZE	16

#define IBMASM_NUM_EVENTS	10
#define IBMASM_EVENT_MAX_SIZE	2048u


struct command {
	struct list_head	queue_node;
	wait_queue_head_t	wait;
	unsigned char		*buffer;
	size_t			buffer_size;
	int			status;
	struct kobject		kobj;
};
#define to_command(c) container_of(c, struct command, kobj)

static inline void command_put(struct command *cmd)
{
        kobject_put(&cmd->kobj);
}

static inline void command_get(struct command *cmd)
{
        kobject_get(&cmd->kobj);
}


struct ibmasm_event {
	unsigned int	serial_number;
	unsigned int	data_size;
	unsigned char	data[IBMASM_EVENT_MAX_SIZE];
};

struct event_buffer {
	struct ibmasm_event	events[IBMASM_NUM_EVENTS];
	unsigned int		next_serial_number;
	unsigned int		next_index;
	struct list_head	readers;
};

struct event_reader {
	unsigned int		next_serial_number;
	wait_queue_head_t	wait;
	struct list_head	node;
	unsigned int		data_size;
	unsigned char		data[IBMASM_EVENT_MAX_SIZE];
};

struct reverse_heartbeat {
	wait_queue_head_t	wait;
	unsigned int		stopped;
};


/* remote console events */
struct mouse_event {
	long		x;
	long		y;
	unsigned char	buttons;
	unsigned char	transitions;
};

struct keyboard_event {
	unsigned long	key_code;
	unsigned char	key_down;
};

struct remote_event {
	unsigned long	type;
	union {
		struct mouse_event	mouse;
		struct keyboard_event	keyboard;
	} data;
};

#define DRIVER_REMOTE_QUEUE_SIZE 240

struct remote_queue {
	struct remote_event	*start;
	struct remote_event	*end;
	struct remote_event	*reader;
	struct remote_event	*writer;
	unsigned int		size;
	int			open;
	wait_queue_head_t	wait;
};


struct service_processor {
	struct list_head	node;
	spinlock_t		lock;
	void __iomem		*base_address;
	unsigned int		irq;
	struct command		*current_command;
	struct command		*heartbeat;
	struct list_head	command_queue;
	struct event_buffer	*event_buffer;
	char			dirname[IBMASM_NAME_SIZE];
	char			devname[IBMASM_NAME_SIZE];
	unsigned int		number;
	struct remote_queue	remote_queue;
	int			serial_line;
	struct device		*dev;
};

/* command processing */
extern struct command *ibmasm_new_command(size_t buffer_size);
extern void ibmasm_exec_command(struct service_processor *sp, struct command *cmd);
extern void ibmasm_wait_for_response(struct command *cmd, int timeout);
extern void ibmasm_receive_command_response(struct service_processor *sp, void *response,  size_t size);

/* event processing */
extern int ibmasm_event_buffer_init(struct service_processor *sp);
extern void ibmasm_event_buffer_exit(struct service_processor *sp);
extern void ibmasm_receive_event(struct service_processor *sp, void *data,  unsigned int data_size);
extern void ibmasm_event_reader_register(struct service_processor *sp, struct event_reader *reader);
extern void ibmasm_event_reader_unregister(struct service_processor *sp, struct event_reader *reader);
extern int ibmasm_get_next_event(struct service_processor *sp, struct event_reader *reader);

/* heartbeat - from SP to OS */
extern void ibmasm_register_panic_notifier(void);
extern void ibmasm_unregister_panic_notifier(void);
extern int ibmasm_heartbeat_init(struct service_processor *sp);
extern void ibmasm_heartbeat_exit(struct service_processor *sp);
extern void ibmasm_receive_heartbeat(struct service_processor *sp,  void *message, size_t size);

/* reverse heartbeat - from OS to SP */
extern void ibmasm_init_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb);
extern int ibmasm_start_reverse_heartbeat(struct service_processor *sp, struct reverse_heartbeat *rhb);
extern void ibmasm_stop_reverse_heartbeat(struct reverse_heartbeat *rhb);

/* dot commands */
extern void ibmasm_receive_message(struct service_processor *sp, void *data, int data_size);
extern int ibmasm_send_driver_vpd(struct service_processor *sp);
extern int ibmasm_send_os_state(struct service_processor *sp, int os_state);

/* low level message processing */
extern int ibmasm_send_i2o_message(struct service_processor *sp);
extern irqreturn_t ibmasm_interrupt_handler(int irq, void * dev_id, struct pt_regs *regs);

/* remote console */
extern void ibmasm_handle_mouse_interrupt(struct service_processor *sp);
extern int ibmasm_init_remote_queue(struct service_processor *sp);
extern void ibmasm_free_remote_queue(struct service_processor *sp);
extern void ibmasm_advance_reader(struct remote_queue *q, unsigned int n);
extern size_t ibmasm_events_available(struct remote_queue *q);

/* file system */
extern int ibmasmfs_register(void);
extern void ibmasmfs_unregister(void);
extern void ibmasmfs_add_sp(struct service_processor *sp);

/* uart */
#ifdef CONFIG_SERIAL_8250
extern void ibmasm_register_uart(struct service_processor *sp);
extern void ibmasm_unregister_uart(struct service_processor *sp);
#else
#define ibmasm_register_uart(sp)	do { } while(0)
#define ibmasm_unregister_uart(sp)	do { } while(0)
#endif