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
15struct 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
24static 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
34static 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
44static 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 (!state) {						\
137			__ret = -ENOMEM;				\
138			goto __fail;					\
139		}							\
140		state->i2c_props.addr = i2caddr;			\
141		state->i2c_props.adap = i2cadap;			\
142		state->i2c_props.name = devname;			\
143		__tuner_info(state->i2c_props,				\
144			     "creating new instance\n");		\
145		list_add_tail(&state->hybrid_tuner_instance_list, &list);\
146		state->i2c_props.count++;				\
147		__ret = state->i2c_props.count;				\
148	}								\
149__fail:									\
150	__ret;								\
151})
152
153#define hybrid_tuner_release_state(state)				\
154({									\
155	int __ret;							\
156	state->i2c_props.count--;					\
157	__ret = state->i2c_props.count;					\
158	if (!state->i2c_props.count) {					\
159		__tuner_info(state->i2c_props, "destroying instance\n");\
160		list_del(&state->hybrid_tuner_instance_list);		\
161		kfree(state);						\
162	}								\
163	__ret;								\
164})
165
166#define hybrid_tuner_report_instance_count(state)			\
167({									\
168	int __ret = 0;							\
169	if (state)							\
170		__ret = state->i2c_props.count;				\
171	__ret;								\
172})
173
174#endif /* __TUNER_I2C_H__ */
175