1/*
2    tuner-i2c.h - i2c interface for different tuners
3
4    Copyright (C) 2007 Michael Krufky (mkrufky@linuxtv.org)
5
6    This program is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 2 of the License, or
9    (at your option) any later version.
10
11    This program is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    GNU General Public License for more details.
15
16    You should have received a copy of the GNU General Public License
17    along with this program; if not, write to the Free Software
18    Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
19*/
20
21#ifndef __TUNER_I2C_H__
22#define __TUNER_I2C_H__
23
24#include <linux/i2c.h>
25#include <linux/slab.h>
26
27struct tuner_i2c_props {
28	u8 addr;
29	struct i2c_adapter *adap;
30
31	/* used for tuner instance management */
32	int count;
33	char *name;
34};
35
36static inline int tuner_i2c_xfer_send(struct tuner_i2c_props *props, char *buf, int len)
37{
38	struct i2c_msg msg = { .addr = props->addr, .flags = 0,
39			       .buf = buf, .len = len };
40	int ret = i2c_transfer(props->adap, &msg, 1);
41
42	return (ret == 1) ? len : ret;
43}
44
45static inline int tuner_i2c_xfer_recv(struct tuner_i2c_props *props, char *buf, int len)
46{
47	struct i2c_msg msg = { .addr = props->addr, .flags = I2C_M_RD,
48			       .buf = buf, .len = len };
49	int ret = i2c_transfer(props->adap, &msg, 1);
50
51	return (ret == 1) ? len : ret;
52}
53
54static inline int tuner_i2c_xfer_send_recv(struct tuner_i2c_props *props,
55					   char *obuf, int olen,
56					   char *ibuf, int ilen)
57{
58	struct i2c_msg msg[2] = { { .addr = props->addr, .flags = 0,
59				    .buf = obuf, .len = olen },
60				  { .addr = props->addr, .flags = I2C_M_RD,
61				    .buf = ibuf, .len = ilen } };
62	int ret = i2c_transfer(props->adap, msg, 2);
63
64	return (ret == 2) ? ilen : ret;
65}
66
67/* Callers must declare as a global for the module:
68 *
69 * static LIST_HEAD(hybrid_tuner_instance_list);
70 *
71 * hybrid_tuner_instance_list should be the third argument
72 * passed into hybrid_tuner_request_state().
73 *
74 * state structure must contain the following:
75 *
76 * 	struct list_head	hybrid_tuner_instance_list;
77 *	struct tuner_i2c_props	i2c_props;
78 *
79 * hybrid_tuner_instance_list (both within state structure and globally)
80 * is only required if the driver is using hybrid_tuner_request_state
81 * and hybrid_tuner_release_state to manage state sharing between
82 * multiple instances of hybrid tuners.
83 */
84
85#define tuner_printk(kernlvl, i2cprops, fmt, arg...) do {		\
86	printk(kernlvl "%s %d-%04x: " fmt, i2cprops.name,		\
87			i2cprops.adap ?					\
88				i2c_adapter_id(i2cprops.adap) : -1,	\
89			i2cprops.addr, ##arg);				\
90	 } while (0)
91
92/* TO DO: convert all callers of these macros to pass in
93 * struct tuner_i2c_props, then remove the macro wrappers */
94
95#define __tuner_warn(i2cprops, fmt, arg...) do {			\
96	tuner_printk(KERN_WARNING, i2cprops, fmt, ##arg);		\
97	} while (0)
98
99#define __tuner_info(i2cprops, fmt, arg...) do {			\
100	tuner_printk(KERN_INFO, i2cprops, fmt, ##arg);			\
101	} while (0)
102
103#define __tuner_err(i2cprops, fmt, arg...) do {				\
104	tuner_printk(KERN_ERR, i2cprops, fmt, ##arg);			\
105	} while (0)
106
107#define __tuner_dbg(i2cprops, fmt, arg...) do {				\
108	if ((debug))							\
109		tuner_printk(KERN_DEBUG, i2cprops, fmt, ##arg);		\
110	} while (0)
111
112#define tuner_warn(fmt, arg...) __tuner_warn(priv->i2c_props, fmt, ##arg)
113#define tuner_info(fmt, arg...) __tuner_info(priv->i2c_props, fmt, ##arg)
114#define tuner_err(fmt, arg...) __tuner_err(priv->i2c_props, fmt, ##arg)
115#define tuner_dbg(fmt, arg...) __tuner_dbg(priv->i2c_props, fmt, ##arg)
116
117/****************************************************************************/
118
119/* The return value of hybrid_tuner_request_state indicates the number of
120 * instances using this tuner object.
121 *
122 * 0 - no instances, indicates an error - kzalloc must have failed
123 *
124 * 1 - one instance, indicates that the tuner object was created successfully
125 *
126 * 2 (or more) instances, indicates that an existing tuner object was found
127 */
128
129#define hybrid_tuner_request_state(type, state, list, i2cadap, i2caddr, devname)\
130({									\
131	int __ret = 0;							\
132	list_for_each_entry(state, &list, hybrid_tuner_instance_list) {	\
133		if (((i2cadap) && (state->i2c_props.adap)) &&		\
134		    ((i2c_adapter_id(state->i2c_props.adap) ==		\
135		      i2c_adapter_id(i2cadap)) &&			\
136		     (i2caddr == state->i2c_props.addr))) {		\
137			__tuner_info(state->i2c_props,			\
138				     "attaching existing instance\n");	\
139			state->i2c_props.count++;			\
140			__ret = state->i2c_props.count;			\
141			break;						\
142		}							\
143	}								\
144	if (0 == __ret) {						\
145		state = kzalloc(sizeof(type), GFP_KERNEL);		\
146		if (NULL == state)					\
147			goto __fail;					\
148		state->i2c_props.addr = i2caddr;			\
149		state->i2c_props.adap = i2cadap;			\
150		state->i2c_props.name = devname;			\
151		__tuner_info(state->i2c_props,				\
152			     "creating new instance\n");		\
153		list_add_tail(&state->hybrid_tuner_instance_list, &list);\
154		state->i2c_props.count++;				\
155		__ret = state->i2c_props.count;				\
156	}								\
157__fail:									\
158	__ret;								\
159})
160
161#define hybrid_tuner_release_state(state)				\
162({									\
163	int __ret;							\
164	state->i2c_props.count--;					\
165	__ret = state->i2c_props.count;					\
166	if (!state->i2c_props.count) {					\
167		__tuner_info(state->i2c_props, "destroying instance\n");\
168		list_del(&state->hybrid_tuner_instance_list);		\
169		kfree(state);						\
170	}								\
171	__ret;								\
172})
173
174#define hybrid_tuner_report_instance_count(state)			\
175({									\
176	int __ret = 0;							\
177	if (state)							\
178		__ret = state->i2c_props.count;				\
179	__ret;								\
180})
181
182#endif /* __TUNER_I2C_H__ */
183