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linux-next/include/linux/i2c-algo-pca.h
Wolfram Sang c01b083105 i2c-algo-pca: Extend for future drivers
The separation between algorithm and adapter was unsharp at places. This was
partly hidden by the fact, that the ISA-driver allowed just one instance and
had all private data in static variables. This patch makes neccessary
preparations to add a platform driver on top of the algorithm, while still
supporting ISA. Note: Due to lack of hardware, the ISA-driver could not be
tested except that it builds.

Concerning the core struct i2c_algo_pca_data:

- A private data field was added, all hardware dependant data may go here.
  Similar to other algorithms, now a pointer to this data is passed to the
  adapter's functions. In order to make as less changes as possible to the
  ISA-driver, it leaves the private data empty and still only uses its static
  variables.

- A "reset_chip" function pointer was added; such a functionality must come
  from the adapter, not the algorithm.

- use a variable "i2c_clock" instead of a function pointer "get_clock",
  allowing for write access to a default in case a wrong value was supplied.

In the algorithm-file:

- move "i2c-pca-algo.h" into "linux/i2c-algo-pca.h"
- now using per_instance timeout values (i2c_adap->timeout)
- error messages specify the device, not only the driver name
- restructure initialization to easily support "i2c_add_numbered_adapter"
- drop "retries" and "own" (i2c address) as they were unused

(The state-machine for I2C-communication was not touched.)

In the ISA-driver:

- adapt to new algorithm

Signed-off-by: Wolfram Sang <w.sang@pengutronix.de>
Signed-off-by: Jean Delvare <khali@linux-fr.org>
2008-04-22 22:16:46 +02:00

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1.3 KiB
C

#ifndef _LINUX_I2C_ALGO_PCA_H
#define _LINUX_I2C_ALGO_PCA_H
/* Clock speeds for the bus */
#define I2C_PCA_CON_330kHz 0x00
#define I2C_PCA_CON_288kHz 0x01
#define I2C_PCA_CON_217kHz 0x02
#define I2C_PCA_CON_146kHz 0x03
#define I2C_PCA_CON_88kHz 0x04
#define I2C_PCA_CON_59kHz 0x05
#define I2C_PCA_CON_44kHz 0x06
#define I2C_PCA_CON_36kHz 0x07
/* PCA9564 registers */
#define I2C_PCA_STA 0x00 /* STATUS Read Only */
#define I2C_PCA_TO 0x00 /* TIMEOUT Write Only */
#define I2C_PCA_DAT 0x01 /* DATA Read/Write */
#define I2C_PCA_ADR 0x02 /* OWN ADR Read/Write */
#define I2C_PCA_CON 0x03 /* CONTROL Read/Write */
#define I2C_PCA_CON_AA 0x80 /* Assert Acknowledge */
#define I2C_PCA_CON_ENSIO 0x40 /* Enable */
#define I2C_PCA_CON_STA 0x20 /* Start */
#define I2C_PCA_CON_STO 0x10 /* Stop */
#define I2C_PCA_CON_SI 0x08 /* Serial Interrupt */
#define I2C_PCA_CON_CR 0x07 /* Clock Rate (MASK) */
struct i2c_algo_pca_data {
void *data; /* private low level data */
void (*write_byte) (void *data, int reg, int val);
int (*read_byte) (void *data, int reg);
int (*wait_for_completion) (void *data);
void (*reset_chip) (void *data);
/* i2c_clock values are defined in linux/i2c-algo-pca.h */
unsigned int i2c_clock;
};
int i2c_pca_add_bus(struct i2c_adapter *);
int i2c_pca_add_numbered_bus(struct i2c_adapter *);
#endif /* _LINUX_I2C_ALGO_PCA_H */