/*
      tuner-i2c.h - i2c interface for different tuners
  
      Copyright (C) 2007 Michael Krufky (mkrufky@linuxtv.org)
  
      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., 675 Mass Ave, Cambridge, MA 02139, USA.
  */
  
  #ifndef __TUNER_I2C_H__
  #define __TUNER_I2C_H__
  
  #include <linux/i2c.h>
  #include <linux/slab.h>
  
  struct tuner_i2c_props {
  	u8 addr;
  	struct i2c_adapter *adap;
  
  	/* used for tuner instance management */
  	int count;
  	char *name;
  };
  
  static inline int tuner_i2c_xfer_send(struct tuner_i2c_props *props, char *buf, int len)
  {
  	struct i2c_msg msg = { .addr = props->addr, .flags = 0,
  			       .buf = buf, .len = len };
  	int ret = i2c_transfer(props->adap, &msg, 1);
  
  	return (ret == 1) ? len : ret;
  }
  
  static inline int tuner_i2c_xfer_recv(struct tuner_i2c_props *props, char *buf, int len)
  {
  	struct i2c_msg msg = { .addr = props->addr, .flags = I2C_M_RD,
  			       .buf = buf, .len = len };
  	int ret = i2c_transfer(props->adap, &msg, 1);
  
  	return (ret == 1) ? len : ret;
  }
  
  static inline int tuner_i2c_xfer_send_recv(struct tuner_i2c_props *props,
  					   char *obuf, int olen,
  					   char *ibuf, int ilen)
  {
  	struct i2c_msg msg[2] = { { .addr = props->addr, .flags = 0,
  				    .buf = obuf, .len = olen },
  				  { .addr = props->addr, .flags = I2C_M_RD,
  				    .buf = ibuf, .len = ilen } };
  	int ret = i2c_transfer(props->adap, msg, 2);
  
  	return (ret == 2) ? ilen : ret;
  }
  
  /* Callers must declare as a global for the module:
   *
   * static LIST_HEAD(hybrid_tuner_instance_list);
   *
   * hybrid_tuner_instance_list should be the third argument
   * passed into hybrid_tuner_request_state().
   *
   * state structure must contain the following:
   *
   * 	struct list_head	hybrid_tuner_instance_list;
   *	struct tuner_i2c_props	i2c_props;
   *
   * hybrid_tuner_instance_list (both within state structure and globally)
   * is only required if the driver is using hybrid_tuner_request_state
   * and hybrid_tuner_release_state to manage state sharing between
   * multiple instances of hybrid tuners.
   */
  
  #define tuner_printk(kernlvl, i2cprops, fmt, arg...) do {		\
  	printk(kernlvl "%s %d-%04x: " fmt, i2cprops.name,		\
  			i2cprops.adap ?					\
  				i2c_adapter_id(i2cprops.adap) : -1,	\
  			i2cprops.addr, ##arg);				\
  	 } while (0)
  
  /* TO DO: convert all callers of these macros to pass in
   * struct tuner_i2c_props, then remove the macro wrappers */
  
  #define __tuner_warn(i2cprops, fmt, arg...) do {			\
  	tuner_printk(KERN_WARNING, i2cprops, fmt, ##arg);		\
  	} while (0)
  
  #define __tuner_info(i2cprops, fmt, arg...) do {			\
  	tuner_printk(KERN_INFO, i2cprops, fmt, ##arg);			\
  	} while (0)
  
  #define __tuner_err(i2cprops, fmt, arg...) do {				\
  	tuner_printk(KERN_ERR, i2cprops, fmt, ##arg);			\
  	} while (0)
  
  #define __tuner_dbg(i2cprops, fmt, arg...) do {				\
  	if ((debug))							\
  		tuner_printk(KERN_DEBUG, i2cprops, fmt, ##arg);		\
  	} while (0)
  
  #define tuner_warn(fmt, arg...) __tuner_warn(priv->i2c_props, fmt, ##arg)
  #define tuner_info(fmt, arg...) __tuner_info(priv->i2c_props, fmt, ##arg)
  #define tuner_err(fmt, arg...) __tuner_err(priv->i2c_props, fmt, ##arg)
  #define tuner_dbg(fmt, arg...) __tuner_dbg(priv->i2c_props, fmt, ##arg)
  
  /****************************************************************************/
  
  /* The return value of hybrid_tuner_request_state indicates the number of
   * instances using this tuner object.
   *
   * 0 - no instances, indicates an error - kzalloc must have failed
   *
   * 1 - one instance, indicates that the tuner object was created successfully
   *
   * 2 (or more) instances, indicates that an existing tuner object was found
   */
  
  #define hybrid_tuner_request_state(type, state, list, i2cadap, i2caddr, devname)\
  ({									\
  	int __ret = 0;							\
  	list_for_each_entry(state, &list, hybrid_tuner_instance_list) {	\
  		if (((i2cadap) && (state->i2c_props.adap)) &&		\
  		    ((i2c_adapter_id(state->i2c_props.adap) ==		\
  		      i2c_adapter_id(i2cadap)) &&			\
  		     (i2caddr == state->i2c_props.addr))) {		\
  			__tuner_info(state->i2c_props,			\
  				     "attaching existing instance
  ");	\
  			state->i2c_props.count++;			\
  			__ret = state->i2c_props.count;			\
  			break;						\
  		}							\
  	}								\
  	if (0 == __ret) {						\
  		state = kzalloc(sizeof(type), GFP_KERNEL);		\
  		if (NULL == state)					\
  			goto __fail;					\
  		state->i2c_props.addr = i2caddr;			\
  		state->i2c_props.adap = i2cadap;			\
  		state->i2c_props.name = devname;			\
  		__tuner_info(state->i2c_props,				\
  			     "creating new instance
  ");		\
  		list_add_tail(&state->hybrid_tuner_instance_list, &list);\
  		state->i2c_props.count++;				\
  		__ret = state->i2c_props.count;				\
  	}								\
  __fail:									\
  	__ret;								\
  })
  
  #define hybrid_tuner_release_state(state)				\
  ({									\
  	int __ret;							\
  	state->i2c_props.count--;					\
  	__ret = state->i2c_props.count;					\
  	if (!state->i2c_props.count) {					\
  		__tuner_info(state->i2c_props, "destroying instance
  ");\
  		list_del(&state->hybrid_tuner_instance_list);		\
  		kfree(state);						\
  	}								\
  	__ret;								\
  })
  
  #define hybrid_tuner_report_instance_count(state)			\
  ({									\
  	int __ret = 0;							\
  	if (state)							\
  		__ret = state->i2c_props.count;				\
  	__ret;								\
  })
  
  #endif /* __TUNER_I2C_H__ */