diff options
Diffstat (limited to 'c/src/lib/libbsp/m68k/mcf5206elite/i2c')
-rw-r--r-- | c/src/lib/libbsp/m68k/mcf5206elite/i2c/.cvsignore | 2 | ||||
-rw-r--r-- | c/src/lib/libbsp/m68k/mcf5206elite/i2c/i2c.c | 316 | ||||
-rw-r--r-- | c/src/lib/libbsp/m68k/mcf5206elite/i2c/i2cdrv.c | 266 |
3 files changed, 584 insertions, 0 deletions
diff --git a/c/src/lib/libbsp/m68k/mcf5206elite/i2c/.cvsignore b/c/src/lib/libbsp/m68k/mcf5206elite/i2c/.cvsignore new file mode 100644 index 0000000000..282522db03 --- /dev/null +++ b/c/src/lib/libbsp/m68k/mcf5206elite/i2c/.cvsignore @@ -0,0 +1,2 @@ +Makefile +Makefile.in diff --git a/c/src/lib/libbsp/m68k/mcf5206elite/i2c/i2c.c b/c/src/lib/libbsp/m68k/mcf5206elite/i2c/i2c.c new file mode 100644 index 0000000000..0dc2b673f6 --- /dev/null +++ b/c/src/lib/libbsp/m68k/mcf5206elite/i2c/i2c.c @@ -0,0 +1,316 @@ +/* I2C bus common (driver-independent) primitives implementation. + * + * 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.OARcorp.com/rtems/license.html. + * + * @(#) $Id$ + */ + +#include <bsp.h> +#include <i2c.h> + +/* i2c_transfer_sema_done_func -- + * This function called from I2C driver layer to signal that I2C + * transfer is finished. This function resumes of task execution which + * has invoked blocking I2C primitive. + * + * PARAMETERS: + * arg - done function argument; it is RTEMS semaphore ID. + */ +static void +i2c_transfer_sema_done_func(rtems_unsigned32 arg) +{ + rtems_id sema = (rtems_id)arg; + rtems_semaphore_release(sema); +} + +/* i2c_transfer_poll_done_func -- + * This function called from I2C driver layer to signal that I2C + * transfer is finished. This function set the flag polled by waiting + * function. + * + * PARAMETERS: + * arg - done function argument; address of poll_done_flag + */ +static void +i2c_transfer_poll_done_func(rtems_unsigned32 arg) +{ + rtems_boolean *poll_done_flag = (rtems_boolean *)arg; + *poll_done_flag = 1; +} + +/* i2c_transfer_wait_sema -- + * Initiate I2C bus transfer and block on temporary created semaphore + * until this transfer will be finished. + * + * PARAMETERS: + * bus - I2C bus number + * msg - pointer to transfer messages array + * nmsg - number of messages in transfer + * + * RETURNS: + * RTEMS_SUCCESSFUL, if tranfer finished successfully, + * or RTEMS status code if semaphore operations has failed. + */ +static i2c_message_status +i2c_transfer_wait_sema(i2c_bus_number bus, i2c_message *msg, int nmsg) +{ + rtems_status_code sc; + rtems_id sema; + sc = rtems_semaphore_create( + rtems_build_name('I', '2', 'C', 'S'), + 0, + RTEMS_COUNTING_SEMAPHORE | RTEMS_NO_INHERIT_PRIORITY | + RTEMS_NO_PRIORITY_CEILING | RTEMS_LOCAL, + 0, + &sema + ); + if (sc != RTEMS_SUCCESSFUL) + return I2C_RESOURCE_NOT_AVAILABLE; + sc = i2c_transfer(bus, nmsg, msg, i2c_transfer_sema_done_func, sema); + if (sc != RTEMS_SUCCESSFUL) + { + rtems_semaphore_delete(sema); + return sc; + } + rtems_semaphore_obtain(sema, RTEMS_WAIT, RTEMS_NO_TIMEOUT); + sc = rtems_semaphore_delete(sema); + return sc; +} + +/* i2c_transfer_wait_poll -- + * Initiate I2C bus transfer and wait by poll transaction done flag until + * this transfer will be finished. + * + * PARAMETERS: + * bus - I2C bus number + * msg - pointer to transfer messages array + * nmsg - number of messages in transfer + * + * RETURNS: + * RTEMS_SUCCESSFUL + */ +static rtems_status_code +i2c_transfer_wait_poll(i2c_bus_number bus, i2c_message *msg, int nmsg) +{ + volatile rtems_boolean poll_done_flag; + rtems_status_code sc; + poll_done_flag = 0; + sc = i2c_transfer(bus, nmsg, msg, i2c_transfer_poll_done_func, + (rtems_unsigned32)&poll_done_flag); + if (sc != RTEMS_SUCCESSFUL) + return sc; + while (poll_done_flag == 0) + { + i2c_poll(bus); + } + return RTEMS_SUCCESSFUL; +} + +/* 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 tranfer 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) +{ + rtems_status_code sc; + int i; + if (_System_state_Is_up(_System_state_Get())) + { + sc = i2c_transfer_wait_sema(bus, msg, nmsg); + } + else + { + sc = i2c_transfer_wait_poll(bus, msg, nmsg); + } + + if (sc != RTEMS_SUCCESSFUL) + return I2C_RESOURCE_NOT_AVAILABLE; + + for (i = 0; i < nmsg; i++) + { + if (msg[i].status != I2C_SUCCESSFUL) + { + return msg[i].status; + } + } + return I2C_SUCCESSFUL; +} + + +/* 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_message msg; + msg.addr = addr; + msg.flags = I2C_MSG_WR; + if (addr > 0xff) + msg.flags |= I2C_MSG_ADDR_10; + msg.status = 0; + msg.len = size; + msg.buf = buf; + return i2c_transfer_wait(bus, &msg, 1); +} + +/* 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, rtems_unsigned8 cmd) +{ + i2c_message msg; + rtems_unsigned8 data = cmd; + msg.addr = addr; + msg.flags = I2C_MSG_WR; + if (addr > 0xff) + msg.flags |= I2C_MSG_ADDR_10; + msg.status = 0; + msg.len = sizeof(data); + msg.buf = &data; + return i2c_transfer_wait(bus, &msg, 1); +} + +/* 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_message msg; + msg.addr = addr; + msg.flags = 0; + if (addr > 0xff) + msg.flags |= I2C_MSG_ADDR_10; + msg.status = 0; + msg.len = size; + msg.buf = buf; + return i2c_transfer_wait(bus, &msg, 1); +} + +/* 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_message msg[2]; + msg[0].addr = addr; + msg[0].flags = I2C_MSG_WR | I2C_MSG_ERRSKIP; + if (addr > 0xff) + msg[0].flags |= I2C_MSG_ADDR_10; + msg[0].status = 0; + msg[0].len = sizew; + msg[0].buf = bufw; + + msg[1].addr = addr; + msg[1].flags = 0; + if (addr > 0xff) + msg[1].flags |= I2C_MSG_ADDR_10; + msg[1].status = 0; + msg[1].len = sizer; + msg[1].buf = bufr; + + return i2c_transfer_wait(bus, msg, 2); +} + +/* 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, rtems_unsigned8 cmd, + void *bufr, int sizer) +{ + i2c_message msg[2]; + rtems_unsigned8 bufw = cmd; + msg[0].addr = addr; + msg[0].flags = I2C_MSG_WR | I2C_MSG_ERRSKIP; + if (addr > 0xff) + msg[0].flags |= I2C_MSG_ADDR_10; + msg[0].status = 0; + msg[0].len = sizeof(bufw); + msg[0].buf = &bufw; + + msg[1].addr = addr; + msg[1].flags = I2C_MSG_ERRSKIP; + if (addr > 0xff) + msg[1].flags |= I2C_MSG_ADDR_10; + msg[1].status = 0; + msg[1].len = sizer; + msg[1].buf = bufr; + + return i2c_transfer_wait(bus, msg, 2); +} diff --git a/c/src/lib/libbsp/m68k/mcf5206elite/i2c/i2cdrv.c b/c/src/lib/libbsp/m68k/mcf5206elite/i2c/i2cdrv.c new file mode 100644 index 0000000000..511a58912e --- /dev/null +++ b/c/src/lib/libbsp/m68k/mcf5206elite/i2c/i2cdrv.c @@ -0,0 +1,266 @@ +/* I2C driver for MCF5206eLITE board. I2C bus accessed through on-chip + * MCF5206e MBUS controller. + * + * The purpose of this module is to perform I2C driver initialization + * and serialize I2C transfers. + * + * 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.OARcorp.com/rtems/license.html. + * + * @(#) $Id$ + */ + +#include <rtems.h> +#include <bsp.h> +#include <stdlib.h> + +#include "i2c.h" +#include "i2cdrv.h" +#include "mcf5206/mcfmbus.h" + +#ifndef I2C_NUMBER_OF_BUSES +#define I2C_NUMBER_OF_BUSES (1) +#endif + +#ifndef I2C_SELECT_BUS +#define I2C_SELECT_BUS(bus) +#endif + +/* + * Few I2C transfers may be posted simultaneously, but MBUS driver is able + * to process it one-by-one. To serialize transfers, function i2c_transfer + * put transfer information to the queue and initiate new transfers if MBUS + * driver is not busy. When driver is busy, next transfer is dequeued + * when current active transfer is finished. + */ + +/* + * i2c_qel - I2C transfers queue element; contain information about + * delayed transfer + */ +typedef struct i2c_qel { + i2c_bus_number bus; /* I2C bus number */ + i2c_message *msg; /* pointer to the transfer' messages array */ + int nmsg; /* number of messages in transfer */ + i2c_transfer_done done; /* transfer done callback function */ + rtems_unsigned32 done_arg; /* arbitrary argument to done callback */ +} i2c_qel; + +/* Memory for I2C transfer queue. This queue represented like a ring buffer */ +static i2c_qel *tqueue; + +/* Maximum number of elements in transfer queue */ +static int tqueue_size; + +/* Position of next free element in a ring buffer */ +static volatile int tqueue_head; + +/* Position of the first element in transfer queue */ +static volatile int tqueue_tail; + +/* MBus I2C bus controller busy flag */ +static volatile rtems_boolean mbus_busy; + +/* MBus I2C bus controller descriptor */ +static mcfmbus mbus; + +/* Clock rate selected for each of bus */ +static int i2cdrv_bus_clock_div[I2C_NUMBER_OF_BUSES]; + +/* Currently selected I2C bus clock rate */ +static int i2cdrv_bus_clock_div_current; + +/* Forward function declaration */ +static void i2cdrv_unload(void); + + +/* i2cdrv_done -- + * Callback function which is called from MBus low-level driver when + * transfer is finished. + */ +static void +i2cdrv_done(rtems_unsigned32 arg) +{ + rtems_interrupt_level level; + i2c_qel *qel = tqueue + tqueue_tail; + qel->done(qel->done_arg); + rtems_interrupt_disable(level); + tqueue_tail = (tqueue_tail + 1) % tqueue_size; + mbus_busy = 0; + rtems_interrupt_enable(level); + i2cdrv_unload(); +} + +/* i2cdrv_unload -- + * If MBUS controller is not busy and transfer waiting in a queue, + * initiate processing of the next transfer in queue. + */ +static void +i2cdrv_unload(void) +{ + rtems_interrupt_level level; + i2c_qel *qel; + rtems_status_code sc; + rtems_interrupt_disable(level); + if (!mbus_busy && (tqueue_head != tqueue_tail)) + { + mbus_busy = 1; + rtems_interrupt_enable(level); + qel = tqueue + tqueue_tail; + + I2C_SELECT_BUS(qel->bus); + if (i2cdrv_bus_clock_div[qel->bus] != i2cdrv_bus_clock_div_current) + { + i2cdrv_bus_clock_div_current = i2cdrv_bus_clock_div[qel->bus]; + mcfmbus_select_clock_divider(&mbus, i2cdrv_bus_clock_div_current); + } + sc = mcfmbus_i2c_transfer(&mbus, qel->nmsg, qel->msg, i2cdrv_done, + (rtems_unsigned32)qel); + if (sc != RTEMS_SUCCESSFUL) + { + int i; + for (i = 0; i < qel->nmsg; i++) + { + qel->msg[i].status = I2C_RESOURCE_NOT_AVAILABLE; + } + i2cdrv_done((rtems_unsigned32)qel); + } + } + else + { + rtems_interrupt_enable(level); + } +} + +/* 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 - arbitrary argument 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, rtems_unsigned32 done_arg) +{ + i2c_qel qel; + rtems_interrupt_level level; + + if (bus >= I2C_NUMBER_OF_BUSES) + { + return RTEMS_INVALID_NUMBER; + } + + if (msg == NULL) + { + return RTEMS_INVALID_ADDRESS; + } + + qel.bus = bus; + qel.msg = msg; + qel.nmsg = nmsg; + qel.done = done; + qel.done_arg = done_arg; + rtems_interrupt_disable(level); + if ((tqueue_head + 1) % tqueue_size == tqueue_tail) + { + rtems_interrupt_enable(level); + return RTEMS_TOO_MANY; + } + memcpy(tqueue + tqueue_head, &qel, sizeof(qel)); + tqueue_head = (tqueue_head + 1) % tqueue_size; + rtems_interrupt_enable(level); + i2cdrv_unload(); + return RTEMS_SUCCESSFUL; +} + + +/* i2cdrv_initialize -- + * I2C driver initialization (rtems I/O driver primitive) + */ +rtems_device_driver +i2cdrv_initialize(rtems_device_major_number major, + rtems_device_minor_number minor, + void *arg) +{ + int i; + rtems_status_code sc; + mbus_busy = 0; + tqueue_tail = tqueue_head = 0; + tqueue_size = 32; + tqueue = calloc(tqueue_size, sizeof(i2c_qel)); + + sc = mcfmbus_initialize(&mbus, MBAR); + if (sc != RTEMS_SUCCESSFUL) + return sc; + + for (i = 0; i < I2C_NUMBER_OF_BUSES; i++) + { + sc = i2c_select_clock_rate(i, 4096); + if (sc != RTEMS_SUCCESSFUL) + return sc; + } + i2cdrv_bus_clock_div_current = -1; + return RTEMS_SUCCESSFUL; +} + +/* 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) +{ + int div; + if (bus >= I2C_NUMBER_OF_BUSES) + return RTEMS_INVALID_NUMBER; + + if (bps == 0) + return RTEMS_UNSATISFIED; + + div = BSP_SYSTEM_FREQUENCY / bps; + i2cdrv_bus_clock_div[bus] = div; + return RTEMS_SUCCESSFUL; +} + + +/* 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) +{ + mcfmbus_poll(&mbus); +} |