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tuner-i2c.h
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1 /*
2  tuner-i2c.h - i2c interface for different tuners
3 
4  Copyright (C) 2007 Michael Krufky ([email protected])
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 
29  struct i2c_adapter *adap;
30 
31  /* used for tuner instance management */
32  int count;
33  char *name;
34 };
35 
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 
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 
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__ */