diff options
Diffstat (limited to 'bsps/m68k/mcf5206elite/include/i2c.h')
| -rw-r--r-- | bsps/m68k/mcf5206elite/include/i2c.h | 243 |
1 files changed, 243 insertions, 0 deletions
diff --git a/bsps/m68k/mcf5206elite/include/i2c.h b/bsps/m68k/mcf5206elite/include/i2c.h new file mode 100644 index 0000000000..8bec067a3a --- /dev/null +++ b/bsps/m68k/mcf5206elite/include/i2c.h @@ -0,0 +1,243 @@ +/* + * Generic I2C bus interface for RTEMS + * + * Copyright (C) 2000 OKTET Ltd., St.-Petersburg, Russia + * Author: Victor V. Vengerov <vvv@oktet.ru> + * + * The license and distribution terms for this file may be + * found in the file LICENSE in this distribution or at + * + * http://www.rtems.org/license/LICENSE. + */ + +#ifndef __RTEMS__I2C_H__ +#define __RTEMS__I2C_H__ + +#include <rtems.h> +#include <bsp.h> +/* This header file define the generic interface to i2c buses available in + * system. This interface may be used by user applications or i2c-device + * drivers (like RTC, NVRAM, etc). + * + * Functions i2c_initialize and i2c_transfer declared in this header usually + * implemented in particular board support package. Usually this + * implementation is a simple wrapper or multiplexor to I2C controller + * driver which is available in system. It may be generic "software + * controller" I2C driver which control SDA and SCL signals directly (if SDA + * and SCL is general-purpose I/O pins), or driver for hardware I2C + * controller (standalone or integrated with processors: MBus controller in + * ColdFire processors, I2C controller in PowerQUICC and so on). + * + * i2c_transfer is a very generic low-level function. Higher-level function + * i2c_write, i2c_read, i2c_wrrd, i2c_wbrd is defined here too. + */ + +/* I2C Bus Number type */ +typedef uint32_t i2c_bus_number; + +/* I2C device address */ +typedef uint16_t i2c_address; + +/* I2C error codes generated during message transfer */ +typedef enum i2c_message_status { + I2C_SUCCESSFUL = 0, + I2C_TIMEOUT, + I2C_NO_DEVICE, + I2C_ARBITRATION_LOST, + I2C_NO_ACKNOWLEDGE, + I2C_NO_DATA, + I2C_RESOURCE_NOT_AVAILABLE +} i2c_message_status; + +/* I2C Message */ +typedef struct i2c_message { + i2c_address addr; /* I2C slave device address */ + uint16_t flags; /* message flags (see below) */ + i2c_message_status status; /* message transfer status code */ + uint16_t len; /* Number of bytes to read or write */ + uint8_t *buf; /* pointer to data array */ +} i2c_message; + +/* I2C message flag */ +#define I2C_MSG_ADDR_10 (0x01) /* 10-bit address */ +#define I2C_MSG_WR (0x02) /* transfer direction for this message + from master to slave */ +#define I2C_MSG_ERRSKIP (0x04) /* Skip message if last transfered message + is failed */ +/* Type for function which is called when transfer over I2C bus is finished */ +typedef void (*i2c_transfer_done) (void *arg); + +/* i2c_initialize -- + * I2C driver initialization. This function usually called on device + * driver initialization state, before initialization task. All I2C + * buses are initialized; reasonable slow data transfer rate is + * selected for each bus. + * + * PARAMETERS: + * major - I2C device major number + * minor - I2C device minor number + * arg - RTEMS driver initialization argument + * + * RETURNS: + * RTEMS status code + */ +rtems_device_driver +i2c_initialize(rtems_device_major_number major, + rtems_device_minor_number minor, + void *arg); + +/* i2c_select_clock_rate -- + * select I2C bus clock rate for specified bus. Some bus controller do not + * allow to select arbitrary clock rate; in this case nearest possible + * slower clock rate is selected. + * + * PARAMETERS: + * bus - I2C bus number + * bps - data transfer rate for this bytes in bits per second + * + * RETURNS: + * RTEMS_SUCCESSFUL, if operation performed successfully, + * RTEMS_INVALID_NUMBER, if wrong bus number is specified, + * RTEMS_UNSATISFIED, if bus do not support data transfer rate selection + * or specified data transfer rate could not be used. + */ +rtems_status_code +i2c_select_clock_rate(i2c_bus_number bus, int bps); + +/* i2c_transfer -- + * Initiate multiple-messages transfer over specified I2C bus or + * put request into queue if bus or some other resource is busy. (This + * is non-blocking function). + * + * PARAMETERS: + * bus - I2C bus number + * nmsg - number of messages + * msg - pointer to messages array + * done - function which is called when transfer is finished + * done_arg_ptr - arbitrary argument ptr passed to done funciton + * + * RETURNS: + * RTEMS_SUCCESSFUL if transfer initiated successfully, or error + * code if something failed. + */ +rtems_status_code +i2c_transfer(i2c_bus_number bus, int nmsg, i2c_message *msg, + i2c_transfer_done done, void * done_arg_ptr); + +/* i2c_transfer_wait -- + * Initiate I2C bus transfer and block until this transfer will be + * finished. This function wait the semaphore if system in + * SYSTEM_STATE_UP state, or poll done flag in other states. + * + * PARAMETERS: + * bus - I2C bus number + * msg - pointer to transfer messages array + * nmsg - number of messages in transfer + * + * RETURNS: + * I2C_SUCCESSFUL, if transfer finished successfully, + * I2C_RESOURCE_NOT_AVAILABLE, if semaphore operations has failed, + * value of status field of first error-finished message in transfer, + * if something wrong. + */ +i2c_message_status +i2c_transfer_wait(i2c_bus_number bus, i2c_message *msg, int nmsg); + +/* i2c_poll -- + * Poll I2C bus controller for events and hanle it. This function is + * used when I2C driver operates in poll-driven mode. + * + * PARAMETERS: + * bus - bus number to be polled + * + * RETURNS: + * none + */ +void +i2c_poll(i2c_bus_number bus); + +/* i2c_write -- + * Send single message over specified I2C bus to addressed device and + * wait while transfer is finished. + * + * PARAMETERS: + * bus - I2C bus number + * addr - address of I2C device + * buf - data to be sent to device + * size - data buffer size + * + * RETURNS: + * transfer status + */ +i2c_message_status +i2c_write(i2c_bus_number bus, i2c_address addr, void *buf, int size); + +/* i2c_wrbyte -- + * Send single one-byte long message over specified I2C bus to + * addressed device and wait while transfer is finished. + * + * PARAMETERS: + * bus - I2C bus number + * addr - address of I2C device + * cmd - byte message to be sent to device + * + * RETURNS: + * transfer status + */ +i2c_message_status +i2c_wrbyte(i2c_bus_number bus, i2c_address addr, uint8_t cmd); + +/* i2c_read -- + * receive single message over specified I2C bus from addressed device. + * This call will wait while transfer is finished. + * + * PARAMETERS: + * bus - I2C bus number + * addr - address of I2C device + * buf - buffer for received message + * size - receive buffer size + * + * RETURNS: + * transfer status + */ +i2c_message_status +i2c_read(i2c_bus_number bus, i2c_address addr, void *buf, int size); + +/* i2c_wrrd -- + * Send message over I2C bus to specified device and receive message + * from the same device during single transfer. + * + * PARAMETERS: + * bus - I2C bus number + * addr - address of I2C device + * bufw - data to be sent to device + * sizew - send data buffer size + * bufr - buffer for received message + * sizer - receive buffer size + * + * RETURNS: + * transfer status + */ +i2c_message_status +i2c_wrrd(i2c_bus_number bus, i2c_address addr, void *bufw, int sizew, + void *bufr, int sizer); + +/* i2c_wbrd -- + * Send one-byte message over I2C bus to specified device and receive + * message from the same device during single transfer. + * + * PARAMETERS: + * bus - I2C bus number + * addr - address of I2C device + * cmd - one-byte message to be sent over I2C bus + * bufr - buffer for received message + * sizer - receive buffer size + * + * RETURNS: + * transfer status + */ +i2c_message_status +i2c_wbrd(i2c_bus_number bus, i2c_address addr, uint8_t cmd, + void *bufr, int sizer); + +#endif |