drivers/media/tuners/tuner-i2c.h

   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
  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__ */