tuner-i2c.h

  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 (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__ */