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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 
27 struct 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 
tuner_i2c_xfer_send(struct tuner_i2c_props * props,char * buf,int len)36 static 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 
tuner_i2c_xfer_recv(struct tuner_i2c_props * props,char * buf,int len)45 static 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 
tuner_i2c_xfer_send_recv(struct tuner_i2c_props * props,char * obuf,int olen,char * ibuf,int ilen)54 static 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