path: root/include/linux/i2c.h

/*   Copyright (C) 1995-2000 Simon G. Vogl

    This program is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation; either version 2 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program; if not, write to the Free Software
    Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
    MA 02110-1301 USA.							     */


#ifndef _LINUX_I2C_H
#define _LINUX_I2C_H

#include <linux/types.h>
#ifdef __KERNEL__
#include <linux/mod_devicetable.h>
#include <linux/device.h>	
#include <linux/sched.h>	
#include <linux/mutex.h>
#include <linux/of.h>		
#include <linux/swab.h>		

extern struct bus_type i2c_bus_type;
extern struct device_type i2c_adapter_type;


struct i2c_msg;
struct i2c_algorithm;
struct i2c_adapter;
struct i2c_client;
struct i2c_driver;
union i2c_smbus_data;
struct i2c_board_info;

struct module;

#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
extern int i2c_master_send(const struct i2c_client *client, const char *buf,
			   int count);
extern int i2c_master_recv(const struct i2c_client *client, char *buf,
			   int count);

extern int i2c_transfer(struct i2c_adapter *adap, struct i2c_msg *msgs,
			int num);

extern s32 i2c_smbus_xfer(struct i2c_adapter *adapter, u16 addr,
			  unsigned short flags, char read_write, u8 command,
			  int size, union i2c_smbus_data *data);


extern s32 i2c_smbus_read_byte(const struct i2c_client *client);
extern s32 i2c_smbus_write_byte(const struct i2c_client *client, u8 value);
extern s32 i2c_smbus_read_byte_data(const struct i2c_client *client,
				    u8 command);
extern s32 i2c_smbus_write_byte_data(const struct i2c_client *client,
				     u8 command, u8 value);
extern s32 i2c_smbus_read_word_data(const struct i2c_client *client,
				    u8 command);
extern s32 i2c_smbus_write_word_data(const struct i2c_client *client,
				     u8 command, u16 value);

static inline s32
i2c_smbus_read_word_swapped(const struct i2c_client *client, u8 command)
{
	s32 value = i2c_smbus_read_word_data(client, command);

	return (value < 0) ? value : swab16(value);
}

static inline s32
i2c_smbus_write_word_swapped(const struct i2c_client *client,
			     u8 command, u16 value)
{
	return i2c_smbus_write_word_data(client, command, swab16(value));
}

extern s32 i2c_smbus_read_block_data(const struct i2c_client *client,
				     u8 command, u8 *values);
extern s32 i2c_smbus_write_block_data(const struct i2c_client *client,
				      u8 command, u8 length, const u8 *values);
extern s32 i2c_smbus_read_i2c_block_data(const struct i2c_client *client,
					 u8 command, u8 length, u8 *values);
extern s32 i2c_smbus_write_i2c_block_data(const struct i2c_client *client,
					  u8 command, u8 length,
					  const u8 *values);
#endif 

struct i2c_driver {
	unsigned int class;

	int (*attach_adapter)(struct i2c_adapter *) __deprecated;
	int (*detach_adapter)(struct i2c_adapter *) __deprecated;

	
	int (*probe)(struct i2c_client *, const struct i2c_device_id *);
	int (*remove)(struct i2c_client *);

	
	void (*shutdown)(struct i2c_client *);
	int (*suspend)(struct i2c_client *, pm_message_t mesg);
	int (*resume)(struct i2c_client *);

	void (*alert)(struct i2c_client *, unsigned int data);

	int (*command)(struct i2c_client *client, unsigned int cmd, void *arg);

	struct device_driver driver;
	const struct i2c_device_id *id_table;

	
	int (*detect)(struct i2c_client *, struct i2c_board_info *);
	const unsigned short *address_list;
	struct list_head clients;
};
#define to_i2c_driver(d) container_of(d, struct i2c_driver, driver)

struct i2c_client {
	unsigned short flags;		
	unsigned short addr;		
					
					
	char name[I2C_NAME_SIZE];
	struct i2c_adapter *adapter;	
	struct i2c_driver *driver;	
	struct device dev;		
	int irq;			
	struct list_head detected;
};
#define to_i2c_client(d) container_of(d, struct i2c_client, dev)

extern struct i2c_client *i2c_verify_client(struct device *dev);

static inline struct i2c_client *kobj_to_i2c_client(struct kobject *kobj)
{
	struct device * const dev = container_of(kobj, struct device, kobj);
	return to_i2c_client(dev);
}

static inline void *i2c_get_clientdata(const struct i2c_client *dev)
{
	return dev_get_drvdata(&dev->dev);
}

static inline void i2c_set_clientdata(struct i2c_client *dev, void *data)
{
	dev_set_drvdata(&dev->dev, data);
}

struct i2c_board_info {
	char		type[I2C_NAME_SIZE];
	unsigned short	flags;
	unsigned short	addr;
	void		*platform_data;
	struct dev_archdata	*archdata;
	struct device_node *of_node;
	int		irq;
};

#define I2C_BOARD_INFO(dev_type, dev_addr) \
	.type = dev_type, .addr = (dev_addr)


#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
extern struct i2c_client *
i2c_new_device(struct i2c_adapter *adap, struct i2c_board_info const *info);

extern struct i2c_client *
i2c_new_probed_device(struct i2c_adapter *adap,
		      struct i2c_board_info *info,
		      unsigned short const *addr_list,
		      int (*probe)(struct i2c_adapter *, unsigned short addr));

extern int i2c_probe_func_quick_read(struct i2c_adapter *, unsigned short addr);

extern struct i2c_client *
i2c_new_dummy(struct i2c_adapter *adap, u16 address);

extern void i2c_unregister_device(struct i2c_client *);
#endif 

#ifdef CONFIG_I2C_BOARDINFO
extern int
i2c_register_board_info(int busnum, struct i2c_board_info const *info,
			unsigned n);
#else
static inline int
i2c_register_board_info(int busnum, struct i2c_board_info const *info,
			unsigned n)
{
	return 0;
}
#endif 

struct i2c_algorithm {
	int (*master_xfer)(struct i2c_adapter *adap, struct i2c_msg *msgs,
			   int num);
	int (*smbus_xfer) (struct i2c_adapter *adap, u16 addr,
			   unsigned short flags, char read_write,
			   u8 command, int size, union i2c_smbus_data *data);

	
	u32 (*functionality) (struct i2c_adapter *);
};

struct i2c_adapter {
	struct module *owner;
	unsigned int class;		  
	const struct i2c_algorithm *algo; 
	void *algo_data;

	
	struct rt_mutex bus_lock;

	int timeout;			
	int retries;
	struct device dev;		

	int nr;
	char name[48];
	struct completion dev_released;

	struct mutex userspace_clients_lock;
	struct list_head userspace_clients;
};
#define to_i2c_adapter(d) container_of(d, struct i2c_adapter, dev)

static inline void *i2c_get_adapdata(const struct i2c_adapter *dev)
{
	return dev_get_drvdata(&dev->dev);
}

static inline void i2c_set_adapdata(struct i2c_adapter *dev, void *data)
{
	dev_set_drvdata(&dev->dev, data);
}

static inline struct i2c_adapter *
i2c_parent_is_i2c_adapter(const struct i2c_adapter *adapter)
{
	struct device *parent = adapter->dev.parent;

	if (parent != NULL && parent->type == &i2c_adapter_type)
		return to_i2c_adapter(parent);
	else
		return NULL;
}

int i2c_for_each_dev(void *data, int (*fn)(struct device *, void *));

void i2c_lock_adapter(struct i2c_adapter *);
void i2c_unlock_adapter(struct i2c_adapter *);

#define I2C_CLIENT_PEC	0x04		
#define I2C_CLIENT_TEN	0x10		
					
#define I2C_CLIENT_WAKE	0x80		

#define I2C_CLASS_HWMON		(1<<0)	
#define I2C_CLASS_DDC		(1<<3)	
#define I2C_CLASS_SPD		(1<<7)	

#define I2C_CLIENT_END		0xfffeU

#define I2C_ADDRS(addr, addrs...) \
	((const unsigned short []){ addr, ## addrs, I2C_CLIENT_END })



#if defined(CONFIG_I2C) || defined(CONFIG_I2C_MODULE)
extern int i2c_add_adapter(struct i2c_adapter *);
extern int i2c_del_adapter(struct i2c_adapter *);
extern int i2c_add_numbered_adapter(struct i2c_adapter *);

extern int i2c_register_driver(struct module *, struct i2c_driver *);
extern void i2c_del_driver(struct i2c_driver *);

#define i2c_add_driver(driver) \
	i2c_register_driver(THIS_MODULE, driver)

extern struct i2c_client *i2c_use_client(struct i2c_client *client);
extern void i2c_release_client(struct i2c_client *client);

extern void i2c_clients_command(struct i2c_adapter *adap,
				unsigned int cmd, void *arg);

extern struct i2c_adapter *i2c_get_adapter(int nr);
extern void i2c_put_adapter(struct i2c_adapter *adap);


static inline u32 i2c_get_functionality(struct i2c_adapter *adap)
{
	return adap->algo->functionality(adap);
}

static inline int i2c_check_functionality(struct i2c_adapter *adap, u32 func)
{
	return (func & i2c_get_functionality(adap)) == func;
}

static inline int i2c_adapter_id(struct i2c_adapter *adap)
{
	return adap->nr;
}

#define module_i2c_driver(__i2c_driver) \
	module_driver(__i2c_driver, i2c_add_driver, \
			i2c_del_driver)

#endif 
#endif 

/**
 * struct i2c_msg - an I2C transaction segment beginning with START
 * @addr: Slave address, either seven or ten bits.  When this is a ten
 *	bit address, I2C_M_TEN must be set in @flags and the adapter
 *	must support I2C_FUNC_10BIT_ADDR.
 * @flags: I2C_M_RD is handled by all adapters.  No other flags may be
 *	provided unless the adapter exported the relevant I2C_FUNC_*
 *	flags through i2c_check_functionality().
 * @len: Number of data bytes in @buf being read from or written to the
 *	I2C slave address.  For read transactions where I2C_M_RECV_LEN
 *	is set, the caller guarantees that this buffer can hold up to
 *	32 bytes in addition to the initial length byte sent by the
 *	slave (plus, if used, the SMBus PEC); and this value will be
 *	incremented by the number of block data bytes received.
 * @buf: The buffer into which data is read, or from which it's written.
 *
 * An i2c_msg is the low level representation of one segment of an I2C
 * transaction.  It is visible to drivers in the @i2c_transfer() procedure,
 * to userspace from i2c-dev, and to I2C adapter drivers through the
 * @i2c_adapter.@master_xfer() method.
 *
 * Except when I2C "protocol mangling" is used, all I2C adapters implement
 * the standard rules for I2C transactions.  Each transaction begins with a
 * START.  That is followed by the slave address, and a bit encoding read
 * versus write.  Then follow all the data bytes, possibly including a byte
 * with SMBus PEC.  The transfer terminates with a NAK, or when all those
 * bytes have been transferred and ACKed.  If this is the last message in a
 * group, it is followed by a STOP.  Otherwise it is followed by the next
 * @i2c_msg transaction segment, beginning with a (repeated) START.
 *
 * Alternatively, when the adapter supports I2C_FUNC_PROTOCOL_MANGLING then
 * passing certain @flags may have changed those standard protocol behaviors.
 * Those flags are only for use with broken/nonconforming slaves, and with
 * adapters which are known to support the specific mangling options they
 * need (one or more of IGNORE_NAK, NO_RD_ACK, NOSTART, and REV_DIR_ADDR).
 */
struct i2c_msg {
	__u16 addr;	
	__u16 flags;
#define I2C_M_TEN		0x0010	
#define I2C_M_RD		0x0001	
#define I2C_M_NOSTART		0x4000	
#define I2C_M_REV_DIR_ADDR	0x2000	
#define I2C_M_IGNORE_NAK	0x1000	
#define I2C_M_NO_RD_ACK		0x0800	
#define I2C_M_RECV_LEN		0x0400	
	__u16 len;		
	__u8 *buf;		
};


#define I2C_FUNC_I2C			0x00000001
#define I2C_FUNC_10BIT_ADDR		0x00000002
#define I2C_FUNC_PROTOCOL_MANGLING	0x00000004 
#define I2C_FUNC_SMBUS_PEC		0x00000008
#define I2C_FUNC_SMBUS_BLOCK_PROC_CALL	0x00008000 
#define I2C_FUNC_SMBUS_QUICK		0x00010000
#define I2C_FUNC_SMBUS_READ_BYTE	0x00020000
#define I2C_FUNC_SMBUS_WRITE_BYTE	0x00040000
#define I2C_FUNC_SMBUS_READ_BYTE_DATA	0x00080000
#define I2C_FUNC_SMBUS_WRITE_BYTE_DATA	0x00100000
#define I2C_FUNC_SMBUS_READ_WORD_DATA	0x00200000
#define I2C_FUNC_SMBUS_WRITE_WORD_DATA	0x00400000
#define I2C_FUNC_SMBUS_PROC_CALL	0x00800000
#define I2C_FUNC_SMBUS_READ_BLOCK_DATA	0x01000000
#define I2C_FUNC_SMBUS_WRITE_BLOCK_DATA 0x02000000
#define I2C_FUNC_SMBUS_READ_I2C_BLOCK	0x04000000 
#define I2C_FUNC_SMBUS_WRITE_I2C_BLOCK	0x08000000 

#define I2C_FUNC_SMBUS_BYTE		(I2C_FUNC_SMBUS_READ_BYTE | \
					 I2C_FUNC_SMBUS_WRITE_BYTE)
#define I2C_FUNC_SMBUS_BYTE_DATA	(I2C_FUNC_SMBUS_READ_BYTE_DATA | \
					 I2C_FUNC_SMBUS_WRITE_BYTE_DATA)
#define I2C_FUNC_SMBUS_WORD_DATA	(I2C_FUNC_SMBUS_READ_WORD_DATA | \
					 I2C_FUNC_SMBUS_WRITE_WORD_DATA)
#define I2C_FUNC_SMBUS_BLOCK_DATA	(I2C_FUNC_SMBUS_READ_BLOCK_DATA | \
					 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA)
#define I2C_FUNC_SMBUS_I2C_BLOCK	(I2C_FUNC_SMBUS_READ_I2C_BLOCK | \
					 I2C_FUNC_SMBUS_WRITE_I2C_BLOCK)

#define I2C_FUNC_SMBUS_EMUL		(I2C_FUNC_SMBUS_QUICK | \
					 I2C_FUNC_SMBUS_BYTE | \
					 I2C_FUNC_SMBUS_BYTE_DATA | \
					 I2C_FUNC_SMBUS_WORD_DATA | \
					 I2C_FUNC_SMBUS_PROC_CALL | \
					 I2C_FUNC_SMBUS_WRITE_BLOCK_DATA | \
					 I2C_FUNC_SMBUS_I2C_BLOCK | \
					 I2C_FUNC_SMBUS_PEC)

#define I2C_SMBUS_BLOCK_MAX	32	
union i2c_smbus_data {
	__u8 byte;
	__u16 word;
	__u8 block[I2C_SMBUS_BLOCK_MAX + 2]; 
			       
};

#define I2C_SMBUS_READ	1
#define I2C_SMBUS_WRITE	0

#define I2C_SMBUS_QUICK		    0
#define I2C_SMBUS_BYTE		    1
#define I2C_SMBUS_BYTE_DATA	    2
#define I2C_SMBUS_WORD_DATA	    3
#define I2C_SMBUS_PROC_CALL	    4
#define I2C_SMBUS_BLOCK_DATA	    5
#define I2C_SMBUS_I2C_BLOCK_BROKEN  6
#define I2C_SMBUS_BLOCK_PROC_CALL   7		
#define I2C_SMBUS_I2C_BLOCK_DATA    8

#endif