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,
  37                                       unsigned char *buf, int len)
  38 {
  39         struct i2c_msg msg = { .addr = props->addr, .flags = 0,
  40                                .buf = buf, .len = len };
  41         int ret = i2c_transfer(props->adap, &msg, 1);
  42
  43         return (ret == 1) ? len : ret;
  44 }
  45
  46 static inline int tuner_i2c_xfer_recv(struct tuner_i2c_props *props,
  47                                       unsigned char *buf, int len)
  48 {
  49         struct i2c_msg msg = { .addr = props->addr, .flags = I2C_M_RD,
  50                                .buf = buf, .len = len };
  51         int ret = i2c_transfer(props->adap, &msg, 1);
  52
  53         return (ret == 1) ? len : ret;
  54 }
  55
  56 static inline int tuner_i2c_xfer_send_recv(struct tuner_i2c_props *props,
  57                                            unsigned char *obuf, int olen,
  58                                            unsigned char *ibuf, int ilen)
  59 {
  60         struct i2c_msg msg[2] = { { .addr = props->addr, .flags = 0,
  61                                     .buf = obuf, .len = olen },
  62                                   { .addr = props->addr, .flags = I2C_M_RD,
  63                                     .buf = ibuf, .len = ilen } };
  64         int ret = i2c_transfer(props->adap, msg, 2);
  65
  66         return (ret == 2) ? ilen : ret;
  67 }
  68
  69 /* Callers must declare as a global for the module:
  70  *
  71  * static LIST_HEAD(hybrid_tuner_instance_list);
  72  *
  73  * hybrid_tuner_instance_list should be the third argument
  74  * passed into hybrid_tuner_request_state().
  75  *
  76  * state structure must contain the following:
  77  *
  78  *      struct list_head        hybrid_tuner_instance_list;
  79  *      struct tuner_i2c_props  i2c_props;
  80  *
  81  * hybrid_tuner_instance_list (both within state structure and globally)
  82  * is only required if the driver is using hybrid_tuner_request_state
  83  * and hybrid_tuner_release_state to manage state sharing between
  84  * multiple instances of hybrid tuners.
  85  */
  86
  87 #define tuner_printk(kernlvl, i2cprops, fmt, arg...) do {               \
  88         printk(kernlvl "%s %d-%04x: " fmt, i2cprops.name,               \
  89                         i2cprops.adap ?                                 \
  90                                 i2c_adapter_id(i2cprops.adap) : -1,     \
  91                         i2cprops.addr, ##arg);                          \
  92          } while (0)
  93
  94 /* TO DO: convert all callers of these macros to pass in
  95  * struct tuner_i2c_props, then remove the macro wrappers */
  96
  97 #define __tuner_warn(i2cprops, fmt, arg...) do {                        \
  98         tuner_printk(KERN_WARNING, i2cprops, fmt, ##arg);               \
  99         } while (0)
 100
 101 #define __tuner_info(i2cprops, fmt, arg...) do {                        \
 102         tuner_printk(KERN_INFO, i2cprops, fmt, ##arg);                  \
 103         } while (0)
 104
 105 #define __tuner_err(i2cprops, fmt, arg...) do {                         \
 106         tuner_printk(KERN_ERR, i2cprops, fmt, ##arg);                   \
 107         } while (0)
 108
 109 #define __tuner_dbg(i2cprops, fmt, arg...) do {                         \
 110         if ((debug))                                                    \
 111                 tuner_printk(KERN_DEBUG, i2cprops, fmt, ##arg);         \
 112         } while (0)
 113
 114 #define tuner_warn(fmt, arg...) __tuner_warn(priv->i2c_props, fmt, ##arg)
 115 #define tuner_info(fmt, arg...) __tuner_info(priv->i2c_props, fmt, ##arg)
 116 #define tuner_err(fmt, arg...) __tuner_err(priv->i2c_props, fmt, ##arg)
 117 #define tuner_dbg(fmt, arg...) __tuner_dbg(priv->i2c_props, fmt, ##arg)
 118
 119 /****************************************************************************/
 120
 121 /* The return value of hybrid_tuner_request_state indicates the number of
 122  * instances using this tuner object.
 123  *
 124  * 0 - no instances, indicates an error - kzalloc must have failed
 125  *
 126  * 1 - one instance, indicates that the tuner object was created successfully
 127  *
 128  * 2 (or more) instances, indicates that an existing tuner object was found
 129  */
 130
 131 #define hybrid_tuner_request_state(type, state, list, i2cadap, i2caddr, devname)\
 132 ({                                                                      \
 133         int __ret = 0;                                                  \
 134         list_for_each_entry(state, &list, hybrid_tuner_instance_list) { \
 135                 if (((i2cadap) && (state->i2c_props.adap)) &&           \
 136                     ((i2c_adapter_id(state->i2c_props.adap) ==          \
 137                       i2c_adapter_id(i2cadap)) &&                       \
 138                      (i2caddr == state->i2c_props.addr))) {             \
 139                         __tuner_info(state->i2c_props,                  \
 140                                      "attaching existing instance\n");  \
 141                         state->i2c_props.count++;                       \
 142                         __ret = state->i2c_props.count;                 \
 143                         break;                                          \
 144                 }                                                       \
 145         }                                                               \
 146         if (0 == __ret) {                                               \
 147                 state = kzalloc(sizeof(type), GFP_KERNEL);              \
 148                 if (NULL == state)                                      \
 149                         goto __fail;                                    \
 150                 state->i2c_props.addr = i2caddr;                        \
 151                 state->i2c_props.adap = i2cadap;                        \
 152                 state->i2c_props.name = devname;                        \
 153                 __tuner_info(state->i2c_props,                          \
 154                              "creating new instance\n");                \
 155                 list_add_tail(&state->hybrid_tuner_instance_list, &list);\
 156                 state->i2c_props.count++;                               \
 157                 __ret = state->i2c_props.count;                         \
 158         }                                                               \
 159 __fail:                                                                 \
 160         __ret;                                                          \
 161 })
 162
 163 #define hybrid_tuner_release_state(state)                               \
 164 ({                                                                      \
 165         int __ret;                                                      \
 166         state->i2c_props.count--;                                       \
 167         __ret = state->i2c_props.count;                                 \
 168         if (!state->i2c_props.count) {                                  \
 169                 __tuner_info(state->i2c_props, "destroying instance\n");\
 170                 list_del(&state->hybrid_tuner_instance_list);           \
 171                 kfree(state);                                           \
 172         }                                                               \
 173         __ret;                                                          \
 174 })
 175
 176 #define hybrid_tuner_report_instance_count(state)                       \
 177 ({                                                                      \
 178         int __ret = 0;                                                  \
 179         if (state)                                                      \
 180                 __ret = state->i2c_props.count;                         \
 181         __ret;                                                          \
 182 })
 183
 184 #endif /* __TUNER_I2C_H__ */