xref: /openbmc/linux/drivers/media/tuners/tuner-i2c.h (revision 9b93eb47)
1 /* SPDX-License-Identifier: GPL-2.0-or-later */
2 /*
3     tuner-i2c.h - i2c interface for different tuners
4 
5     Copyright (C) 2007 Michael Krufky (mkrufky@linuxtv.org)
6 
7 */
8 
9 #ifndef __TUNER_I2C_H__
10 #define __TUNER_I2C_H__
11 
12 #include <linux/i2c.h>
13 #include <linux/slab.h>
14 
15 struct tuner_i2c_props {
16 	u8 addr;
17 	struct i2c_adapter *adap;
18 
19 	/* used for tuner instance management */
20 	int count;
21 	char *name;
22 };
23 
24 static inline int tuner_i2c_xfer_send(struct tuner_i2c_props *props,
25 				      unsigned char *buf, int len)
26 {
27 	struct i2c_msg msg = { .addr = props->addr, .flags = 0,
28 			       .buf = buf, .len = len };
29 	int ret = i2c_transfer(props->adap, &msg, 1);
30 
31 	return (ret == 1) ? len : ret;
32 }
33 
34 static inline int tuner_i2c_xfer_recv(struct tuner_i2c_props *props,
35 				      unsigned char *buf, int len)
36 {
37 	struct i2c_msg msg = { .addr = props->addr, .flags = I2C_M_RD,
38 			       .buf = buf, .len = len };
39 	int ret = i2c_transfer(props->adap, &msg, 1);
40 
41 	return (ret == 1) ? len : ret;
42 }
43 
44 static inline int tuner_i2c_xfer_send_recv(struct tuner_i2c_props *props,
45 					   unsigned char *obuf, int olen,
46 					   unsigned char *ibuf, int ilen)
47 {
48 	struct i2c_msg msg[2] = { { .addr = props->addr, .flags = 0,
49 				    .buf = obuf, .len = olen },
50 				  { .addr = props->addr, .flags = I2C_M_RD,
51 				    .buf = ibuf, .len = ilen } };
52 	int ret = i2c_transfer(props->adap, msg, 2);
53 
54 	return (ret == 2) ? ilen : ret;
55 }
56 
57 /* Callers must declare as a global for the module:
58  *
59  * static LIST_HEAD(hybrid_tuner_instance_list);
60  *
61  * hybrid_tuner_instance_list should be the third argument
62  * passed into hybrid_tuner_request_state().
63  *
64  * state structure must contain the following:
65  *
66  *	struct list_head	hybrid_tuner_instance_list;
67  *	struct tuner_i2c_props	i2c_props;
68  *
69  * hybrid_tuner_instance_list (both within state structure and globally)
70  * is only required if the driver is using hybrid_tuner_request_state
71  * and hybrid_tuner_release_state to manage state sharing between
72  * multiple instances of hybrid tuners.
73  */
74 
75 #define tuner_printk(kernlvl, i2cprops, fmt, arg...) do {		\
76 	printk(kernlvl "%s %d-%04x: " fmt, i2cprops.name,		\
77 			i2cprops.adap ?					\
78 				i2c_adapter_id(i2cprops.adap) : -1,	\
79 			i2cprops.addr, ##arg);				\
80 	 } while (0)
81 
82 /* TO DO: convert all callers of these macros to pass in
83  * struct tuner_i2c_props, then remove the macro wrappers */
84 
85 #define __tuner_warn(i2cprops, fmt, arg...) do {			\
86 	tuner_printk(KERN_WARNING, i2cprops, fmt, ##arg);		\
87 	} while (0)
88 
89 #define __tuner_info(i2cprops, fmt, arg...) do {			\
90 	tuner_printk(KERN_INFO, i2cprops, fmt, ##arg);			\
91 	} while (0)
92 
93 #define __tuner_err(i2cprops, fmt, arg...) do {				\
94 	tuner_printk(KERN_ERR, i2cprops, fmt, ##arg);			\
95 	} while (0)
96 
97 #define __tuner_dbg(i2cprops, fmt, arg...) do {				\
98 	if ((debug))							\
99 		tuner_printk(KERN_DEBUG, i2cprops, fmt, ##arg);		\
100 	} while (0)
101 
102 #define tuner_warn(fmt, arg...) __tuner_warn(priv->i2c_props, fmt, ##arg)
103 #define tuner_info(fmt, arg...) __tuner_info(priv->i2c_props, fmt, ##arg)
104 #define tuner_err(fmt, arg...) __tuner_err(priv->i2c_props, fmt, ##arg)
105 #define tuner_dbg(fmt, arg...) __tuner_dbg(priv->i2c_props, fmt, ##arg)
106 
107 /****************************************************************************/
108 
109 /* The return value of hybrid_tuner_request_state indicates the number of
110  * instances using this tuner object.
111  *
112  * 0 - no instances, indicates an error - kzalloc must have failed
113  *
114  * 1 - one instance, indicates that the tuner object was created successfully
115  *
116  * 2 (or more) instances, indicates that an existing tuner object was found
117  */
118 
119 #define hybrid_tuner_request_state(type, state, list, i2cadap, i2caddr, devname)\
120 ({									\
121 	int __ret = 0;							\
122 	list_for_each_entry(state, &list, hybrid_tuner_instance_list) {	\
123 		if (((i2cadap) && (state->i2c_props.adap)) &&		\
124 		    ((i2c_adapter_id(state->i2c_props.adap) ==		\
125 		      i2c_adapter_id(i2cadap)) &&			\
126 		     (i2caddr == state->i2c_props.addr))) {		\
127 			__tuner_info(state->i2c_props,			\
128 				     "attaching existing instance\n");	\
129 			state->i2c_props.count++;			\
130 			__ret = state->i2c_props.count;			\
131 			break;						\
132 		}							\
133 	}								\
134 	if (0 == __ret) {						\
135 		state = kzalloc(sizeof(type), GFP_KERNEL);		\
136 		if (NULL == state)					\
137 			goto __fail;					\
138 		state->i2c_props.addr = i2caddr;			\
139 		state->i2c_props.adap = i2cadap;			\
140 		state->i2c_props.name = devname;			\
141 		__tuner_info(state->i2c_props,				\
142 			     "creating new instance\n");		\
143 		list_add_tail(&state->hybrid_tuner_instance_list, &list);\
144 		state->i2c_props.count++;				\
145 		__ret = state->i2c_props.count;				\
146 	}								\
147 __fail:									\
148 	__ret;								\
149 })
150 
151 #define hybrid_tuner_release_state(state)				\
152 ({									\
153 	int __ret;							\
154 	state->i2c_props.count--;					\
155 	__ret = state->i2c_props.count;					\
156 	if (!state->i2c_props.count) {					\
157 		__tuner_info(state->i2c_props, "destroying instance\n");\
158 		list_del(&state->hybrid_tuner_instance_list);		\
159 		kfree(state);						\
160 	}								\
161 	__ret;								\
162 })
163 
164 #define hybrid_tuner_report_instance_count(state)			\
165 ({									\
166 	int __ret = 0;							\
167 	if (state)							\
168 		__ret = state->i2c_props.count;				\
169 	__ret;								\
170 })
171 
172 #endif /* __TUNER_I2C_H__ */
173