linux-stable/include/linux/i2c-algo-pcf.h
David Miller 30091404af i2c-algo-pcf: Add adapter hooks around xfer begin and end
Some I2C bus implementations need to synchronize with external
entities, such as system firmware, which might also be programming the
same I2C bus.

In order to facilitate this add ->xfer_begin() and ->xfer_end() hooks
which are invoked around pcf_xfer().

[JD: Make these hooks optional.]

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-10-22 20:21:30 +02:00

48 lines
1.9 KiB
C

/* ------------------------------------------------------------------------- */
/* adap-pcf.h i2c driver algorithms for PCF8584 adapters */
/* ------------------------------------------------------------------------- */
/* Copyright (C) 1995-97 Simon G. Vogl
1998-99 Hans Berglund
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., 675 Mass Ave, Cambridge, MA 02139, USA. */
/* ------------------------------------------------------------------------- */
/* With some changes from Kyösti Mälkki <kmalkki@cc.hut.fi> and even
Frodo Looijaard <frodol@dds.nl> */
#ifndef _LINUX_I2C_ALGO_PCF_H
#define _LINUX_I2C_ALGO_PCF_H
struct i2c_algo_pcf_data {
void *data; /* private data for lolevel routines */
void (*setpcf) (void *data, int ctl, int val);
int (*getpcf) (void *data, int ctl);
int (*getown) (void *data);
int (*getclock) (void *data);
void (*waitforpin) (void *data);
void (*xfer_begin) (void *data);
void (*xfer_end) (void *data);
/* Multi-master lost arbitration back-off delay (msecs)
* This should be set by the bus adapter or knowledgable client
* if bus is multi-mastered, else zero
*/
unsigned long lab_mdelay;
};
int i2c_pcf_add_bus(struct i2c_adapter *);
#endif /* _LINUX_I2C_ALGO_PCF_H */