/* This file contains the GRASCS RTEMS driver
*
* COPYRIGHT (c) 2008.
* Cobham Gaisler AB.
*
* 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.
*/
#include <stdlib.h>
#include <bsp.h>
#include <grlib/ambapp.h>
#include <grlib/grascs.h>
#include <grlib/grlib.h>
#include <grlib/grlib_impl.h>
#ifndef GAISLER_ASCS
#define GAISLER_ASCS 0x043
#endif
#ifdef DEBUG
#define DBG(x...) printk(x)
#else
#define DBG(x...)
#endif
typedef struct {
volatile unsigned int cmd;
volatile unsigned int clk;
volatile unsigned int sts;
volatile unsigned int tcd;
volatile unsigned int tmd;
} GRASCS_regs;
typedef struct {
unsigned char tmconf;
unsigned char usconf;
unsigned char nslaves;
unsigned char dbits;
int clkfreq;
} GRASCS_caps;
typedef struct {
GRASCS_regs *regs; /* Pointer to core registers */
GRASCS_caps *caps; /* Pointer to capability struct */
rtems_id tcsem1, tcsem2;
rtems_id tmsem1, tmsem2;
volatile char running;
int tcptr;
int tmptr;
int tcwords;
int tmwords;
} GRASCS_cfg;
static GRASCS_cfg *cfg = NULL;
/*------------------------------------*/
/* Start of internal helper functions */
/*------------------------------------*/
/* Function: ASCS_getaddr
Arguments: base: Core's register base address
irq: Core's irq
Return values: 0 if successful, -1 if core is not found
Description: Assigns core's register base address and
irq to arguments. Uses AMBA plug and play to find the
core.
*/
static int ASCS_get_addr(int *base, int *irq) {
struct ambapp_apb_info core;
if(ambapp_find_apbslv(&ambapp_plb, VENDOR_GAISLER, GAISLER_ASCS, &core) == 1) {
*base = core.start;
*irq = core.common.irq;
DBG("ASCS_get_addr: Registerd ASCS core at 0x%x with irq %i\n",core.start, core.irq);
return 0;
}
DBG("ASCS_get_addr: Failed to detect core\n");
return -1;
}
/* Function: ASCS_calc_clkreg
Arguments: sysfreq: System clock frequency in kHz
etrfreq: ETR frequency in Hz
Return values: Value of core's CLK-register
Description: Calculates value of core's CLK-register. See
GRASCS IP core documentation for details.
*/
static int ASCS_calc_clkreg(int sysfreq, int etrfreq) {
if(cfg->caps->usconf)
return 1000000/etrfreq;
else
return sysfreq*1000/etrfreq;
}
/* Function: ASCS_get_sysfreq
Arguments: -
Return values: System clock frequency in kHz, -1 if failed
Description: Uses AMBA plug and play to lookup system frequency
*/
static int ASCS_get_sysfreq(void) {
struct ambapp_apb_info gpt;
struct gptimer_regs *tregs;
int tmp;
if(ambapp_find_apbslv(&ambapp_plb, VENDOR_GAISLER, GAISLER_GPTIMER, &gpt) == 1) {
tregs = (struct gptimer_regs *) gpt.start;
tmp = (tregs->scaler_reload + 1)*1000;
DBG("ASCS_get_sysfreq: Detected system frequency %i kHz\n",tmp);
if((tmp < GRASCS_MIN_SFREQ) || (tmp > GRASCS_MAX_SFREQ)) {
DBG("ASCS_get_sysfreq: System frequency is invalid for ASCS core\n");
return -1;
}
else
return (tregs->scaler_reload + 1)*1000;
}
DBG("ASCS_get_sysfreq: Failed to detect system frequency\n");
return -1;
}
/* Function: ASCS_irqhandler
Arguments: v: not used
Return values: -
Description: Determines the source of the interrupt, clears the
appropriate bits in the core's STS register and releases
the associated semaphore
*/
static rtems_isr ASCS_irqhandler(void *v) {
if(cfg->regs->sts & GRASCS_STS_TCDONE) {
/* Clear TC done bit */
cfg->regs->sts |= GRASCS_STS_TCDONE;
if(--cfg->tcwords == 0)
/* No more TCs to perform right now */
rtems_semaphore_release(cfg->tcsem2);
else {
/* Block not sent yet, start next TC */
if(cfg->caps->dbits == 8) {
cfg->tcptr++;
cfg->regs->tcd = *((unsigned char*)cfg->tcptr);
}
else if(cfg->caps->dbits == 16) {
cfg->tcptr += 2;
cfg->regs->tcd = *((unsigned short int*)cfg->tcptr);
}
else {
cfg->tcptr += 4;
cfg->regs->tcd = *((unsigned int*)cfg->tcptr);
}
}
}
if(cfg->regs->sts & GRASCS_STS_TMDONE) {
/* Clear TM done bit */
cfg->regs->sts |= GRASCS_STS_TMDONE;
/* Store received data */
if(cfg->caps->dbits == 8) {
*((unsigned char*)cfg->tmptr) = (unsigned char)(cfg->regs->tmd & 0xFF);
cfg->tmptr++;
}
else if(cfg->caps->dbits == 16) {
*((unsigned short int*)cfg->tmptr) = (unsigned short int)(cfg->regs->tmd & 0xFFFF);
cfg->tmptr += 2;
}
else {
*((unsigned int*)cfg->tmptr) = cfg->regs->tmd;
cfg->tmptr += 4;
}
if(--cfg->tmwords == 0)
/* No more TMs to perform right now */
rtems_semaphore_release(cfg->tmsem2);
else
/* Block not received yet, start next TM */
cfg->regs->cmd |= GRASCS_CMD_SENDTM;
}
}
/*---------------------------*/
/* Start of driver interface */
/*---------------------------*/
/* Function: ASCS_init
Arguments: -
Return values: 0 if successful, -1 if unsuccessful
Description: Initializes the ASCS core
*/
int ASCS_init(void) {
int base, irq, tmp;
DBG("ASCS_init: Starting initialization of ASCS core\n");
/* Allocate memory for config, status and capability struct */
if((cfg = grlib_malloc(sizeof(*cfg))) == NULL) {
DBG("ASCS_init: Could not allocate memory for cfg struc\n");
return -1;
}
if((cfg->caps = grlib_calloc(1,sizeof(*cfg->caps))) == NULL) {
DBG("ASCS_init: Could not allocate memory for caps struc\n");
goto init_error1;
}
/* Create semaphores for blocking ASCS_TC/TM functions */
if(rtems_semaphore_create(rtems_build_name('A','S','C','0'),1,
(RTEMS_FIFO|RTEMS_SIMPLE_BINARY_SEMAPHORE|
RTEMS_NO_INHERIT_PRIORITY|RTEMS_LOCAL|
RTEMS_NO_PRIORITY_CEILING), 0,
&cfg->tcsem1) != RTEMS_SUCCESSFUL) {
DBG("ASCS_init: Failed to create semaphore ASC0\n");
goto init_error2;
}
if(rtems_semaphore_create(rtems_build_name('A','S','C','1'),1,
(RTEMS_FIFO|RTEMS_SIMPLE_BINARY_SEMAPHORE|
RTEMS_NO_INHERIT_PRIORITY|RTEMS_LOCAL|
RTEMS_NO_PRIORITY_CEILING), 0,
&cfg->tmsem1) != RTEMS_SUCCESSFUL) {
DBG("ASCS_init: Failed to create semaphore ASC1\n");
goto init_error2;
}
/* Create semaphores for waiting on ASCS_TC/TM interrupt */
if(rtems_semaphore_create(rtems_build_name('A','S','C','2'),0,
(RTEMS_FIFO|RTEMS_SIMPLE_BINARY_SEMAPHORE|
RTEMS_NO_INHERIT_PRIORITY|RTEMS_LOCAL|
RTEMS_NO_PRIORITY_CEILING), 0,
&cfg->tcsem2) != RTEMS_SUCCESSFUL) {
DBG("ASCS_init: Failed to create semaphore ASC2\n");
goto init_error2;
}
if(rtems_semaphore_create(rtems_build_name('A','S','C','3'),0,
(RTEMS_FIFO|RTEMS_SIMPLE_BINARY_SEMAPHORE|
RTEMS_NO_INHERIT_PRIORITY|RTEMS_LOCAL|
RTEMS_NO_PRIORITY_CEILING), 0,
&cfg->tmsem2) != RTEMS_SUCCESSFUL) {
DBG("ASCS_init: Failed to create semaphore ASC3\n");
goto init_error2;
}
/* Set pointer to core registers */
if(ASCS_get_addr(&base, &irq) == -1)
goto init_error2;
cfg->regs = (GRASCS_regs*)base;
/* Read core capabilities */
tmp = cfg->regs->sts;
cfg->caps->dbits = ((tmp >> GRASCS_STS_DBITS_BITS) & 0x1F) + 1;
cfg->caps->nslaves = ((tmp >> GRASCS_STS_NSLAVES_BITS) & 0xF) + 1;
cfg->caps->tmconf = (tmp >> GRASCS_STS_TMCONF_BITS) & 0x1;
cfg->caps->usconf = (tmp >> GRASCS_STS_USCONF_BITS) & 0x1;
/* Reset and configure core */
cfg->running = 0;
cfg->regs->cmd |= GRASCS_CMD_RESET;
if((tmp = ASCS_get_sysfreq()) == -1)
goto init_error2;
cfg->caps->clkfreq = tmp;
while(ASCS_iface_status())
;
cfg->regs->clk = ASCS_calc_clkreg(tmp, GRASCS_DEFAULT_ETRFREQ);
cfg->regs->cmd = GRASCS_CMD_US1C;
cfg->regs->cmd |= (tmp/1000 << GRASCS_CMD_US1_BITS) | GRASCS_CMD_US1C |
GRASCS_CMD_TCDONE | GRASCS_CMD_TMDONE;
/* Register interrupt routine */
rtems_interrupt_handler_install(irq, "grascs",
RTEMS_INTERRUPT_SHARED,
ASCS_irqhandler, NULL);
return 0;
init_error2:
free(cfg->caps);
init_error1:
free(cfg);
return -1;
}
/* Function: ASCS_input_select
Arguments: slave: The number of the slave that is active,
numbered from 0-15
Return values: 0 if successful, -GRASCS_ERROR_CAPFAULT if slave value
is negative or too big, -GRASCS_ERROR_TRANSACTIVE if
a TM is active.
Description: Sets the slave_sel bits in the core's CMD register.
they are used to choose which slave the core listens
to when performing a TM. The bits can't be set
during a TM, and the function will in such a case fail.
*/
int ASCS_input_select(int slave) {
if((slave < 0) || (slave > cfg->caps->nslaves)) {
/* Slave number is negative or too big */
DBG("ASCS_input_select: Wrong slave number\n");
return -GRASCS_ERROR_CAPFAULT;
}
if(rtems_semaphore_obtain(cfg->tmsem1,RTEMS_NO_WAIT,RTEMS_NO_TIMEOUT) !=
RTEMS_SUCCESSFUL) {
/* Can't change active slave during a TM */
DBG("ASCS_input_select: Transaction active\n");
return -GRASCS_ERROR_TRANSACTIVE;
}
cfg->regs->cmd = ((cfg->regs->cmd &= ~GRASCS_CMD_SLAVESEL) |
(slave << GRASCS_CMD_SLAVESEL_BITS));
rtems_semaphore_release(cfg->tmsem1);
return 0;
}
/* Function: ASCS_etr_select
Arguments: src: The source of the ETR signal, valid values are
0-GRASCS_MAX_TMS (0 = internal source, 1-GRASCS_MAX_TMS =
external time markers 1-GRASCS_MAX_TMS).
freq: ETR frequency in Hz. Valid values are
GRASCS_MIN_ETRFREQ-GRASCS_MAX_ETRFREQ
Return values: 0 if successful, -GRASCS_ERROR_CAPFAULT if src or freq values
are invalid, -GRASCS_ERROR_STARTSTOP if synchronization interface
isn't stopped.
Description: Changes the source for the ETR signal. The frequency of source signal
is assumed to be the same as the frequency of the freq input
*/
int ASCS_etr_select(int etr, int freq) {
if((etr < 0) || (etr > GRASCS_MAX_TMS) || ((cfg->caps->tmconf == 0) && (etr > 0)) ||
(freq < GRASCS_MIN_ETRFREQ) || (freq > GRASCS_MAX_ETRFREQ)) {
/* ETR source value or frequency is invalid */
DBG("ASCS_etr_select: Wrong etr src number or wrong frequency\n");
return -GRASCS_ERROR_CAPFAULT;
}
if(cfg->regs->sts & GRASCS_STS_ERUNNING) {
/* Synchronization interface is running */
DBG("ASCS_etr_select: Synch interface is running\n");
return -GRASCS_ERROR_STARTSTOP;
}
cfg->regs->clk = ASCS_calc_clkreg(cfg->caps->clkfreq,freq);
cfg->regs->cmd = ((cfg->regs->cmd &= ~GRASCS_CMD_ETRCTRL) |
(etr << GRASCS_CMD_ETRCTRL_BITS));
return 0;
}
/* Function: ASCS_start
Arguments: -
Return values: -
Description: Enables the serial interface.
*/
void ASCS_start(void) {
/* Set register and internal status to running */
cfg->regs->cmd |= GRASCS_CMD_STARTSTOP;
cfg->running = 1;
}
/* Function: ASCS_stop
Arguments: -
Return values: -
Description: Disables the serial interface. This function will
block until possible calls to TC_send(_block) and
TM_recv(_block) has returned in order to be sure
that started transactions will be performed.
*/
void ASCS_stop(void) {
/* Set internal status to stopped */
cfg->running = 0;
/* Obtain semaphores to avoid possible situation where a
TC_send(_block) or TM_recv(_block) is aborted and driver is
waiting forever for an interrupt */
rtems_semaphore_obtain(cfg->tcsem1,RTEMS_WAIT,RTEMS_NO_TIMEOUT);
rtems_semaphore_obtain(cfg->tmsem1,RTEMS_WAIT,RTEMS_NO_TIMEOUT);
/* Change actual register value */
cfg->regs->cmd &= ~GRASCS_CMD_STARTSTOP;
/* Release the semaphores */
rtems_semaphore_release(cfg->tcsem1);
rtems_semaphore_release(cfg->tmsem1);
}
/* Function: ASCS_iface_status
Arguments: -
Return values: 0 if both serial interface and synch interface is stopped,
1 if serial interface is running buth synch interface is
stopped, 2 if serial interface is stopped but synch interface
is running, 3 if both serial and synch interface is running
Description: Reads the core's STS register and reports the status of the
serial and synch interfaces
*/
int ASCS_iface_status(void) {
return ((cfg->regs->sts & 0x3) & (0x2 | cfg->running));
}
/* Function: ASCS_TC_send
Arguments: word: Pointer to a word that should be sent
Return values: 0 on success
-GRASCS_ERROR_STARTSTOP if serial interface is stopped,
-GRASCS_ERROR_TRANSACTIVE if another TC is in progress.
Description: Start a TC and sends the data that word points to.
*/
int ASCS_TC_send(int *word) {
int retval;
if(rtems_semaphore_obtain(cfg->tcsem1,RTEMS_NO_WAIT,RTEMS_NO_TIMEOUT) !=
RTEMS_SUCCESSFUL) {
/* Can't start a TC_send if another TC_send of TC_send_block is
in progress */
DBG("ASCS_TC_send: Could not obtain semaphore, transcation probably in progress\n");
return -GRASCS_ERROR_TRANSACTIVE;
}
if(!cfg->running) {
/* Can't start a TC if serial interface isn't started */
DBG("ASCS_TC_send: Serial interface is not started\n");
retval = -GRASCS_ERROR_STARTSTOP;
}
else {
/* Start the transfer */
cfg->tcwords = 1;
if(cfg->caps->dbits == 8)
cfg->regs->tcd = *((unsigned char*)word);
else if(cfg->caps->dbits == 16)
cfg->regs->tcd = *((unsigned short int*)((int)word & ~1));
else
cfg->regs->tcd = *((unsigned int*)((int)word & ~3));
/* Wait until transfer is complete */
rtems_semaphore_obtain(cfg->tcsem2,RTEMS_WAIT,RTEMS_NO_TIMEOUT);
retval = 0;
}
rtems_semaphore_release(cfg->tcsem1);
return retval;
}
/* Function: ASCS_TC_send_block
Arguments: block: Pointer to the start of a datablock that
should be sent.
ntrans: Number of transfers needed to transfer
the block.
Return values: 0 if successfull, -GRASCS_ERROR_STARTSTOP if TC
couldn't be started because serial interface is
stopped, -GRASCS_ERROR_TRANSACTIVE if TC couldn't
be started because another TC isn't done yet.
Description: Starts ntrans TCs and sends the data that starts at the
address that block points to. The size of each
transaction will vary depending on whether the core is
configured for 8, 16, or 32 bits data transfers.
*/
int ASCS_TC_send_block(int *block, int ntrans) {
int retval;
if(rtems_semaphore_obtain(cfg->tcsem1,RTEMS_NO_WAIT,RTEMS_NO_TIMEOUT) !=
RTEMS_SUCCESSFUL) {
/* Can't start a TC_send_block if another TC_send of TC_send_block is
in progress */
DBG("ASCS_TC_send_block: Could not obtain semaphore, transcation probably in progress\n");
return -GRASCS_ERROR_TRANSACTIVE;
}
if(!cfg->running) {
/* Can't start a TC if serial interface isn't started */
DBG("ASCS_TC_send_block: Serial interface is not started\n");
retval = -GRASCS_ERROR_STARTSTOP;
}
else {
/* Start the first transfer */
cfg->tcwords = ntrans;
if(cfg->caps->dbits == 8) {
cfg->tcptr = (int)block;
cfg->regs->tcd = *((unsigned char*)cfg->tcptr);
}
else if(cfg->caps->dbits == 16) {
cfg->tcptr = (int)block & ~1;
cfg->regs->tcd = *((unsigned short int*)cfg->tcptr);
}
else {
cfg->tcptr = (int)block & ~3;
cfg->regs->tcd = *((unsigned int*)cfg->tcptr);
}
/* Wait until all transfers are complete */
rtems_semaphore_obtain(cfg->tcsem2,RTEMS_WAIT,RTEMS_NO_TIMEOUT);
retval = 0;
}
rtems_semaphore_release(cfg->tcsem1);
return retval;
}
/* Function: ASCS_TC_sync_start
Arguments: -
Return values: -
Description: Starts synchronization interface. Might
be delayed if a TM is in progress. SW can poll
ASCS_iface_status() to find out when synch interface is
started. First ETR pulse can be delay up to one ETR
period depending on the source of the ETR and
activity on the TM line.
*/
void ASCS_TC_sync_start(void) {
cfg->regs->cmd |= GRASCS_CMD_ESTARTSTOP;
}
/* Function: ASCS_TC_sync_stop
Arguments: -
Return values: -
Description: Stops the synchronization interface. Might
be delayed for 1 us if a ETR pulse is being generated. SW
can determine when synch interface has stopped by polling
ASCS_iface_status().
*/
void ASCS_TC_sync_stop(void) {
cfg->regs->cmd &= ~GRASCS_CMD_ESTARTSTOP;
}
/* Function: ASCS_TM_recv
Arguments: word: Pointer to where the received word should be
placed
Return values: 0 if successful, -GRASCS_ERROR_STARTSTOP if serial
interface isn't started, -GRASCS_ERROR_TRANSACTIVE
if another TM is in progress
Description: Starts a TM and stores the incoming data in word.
*/
int ASCS_TM_recv(int *word) {
int retval;
if(rtems_semaphore_obtain(cfg->tmsem1,RTEMS_NO_WAIT,RTEMS_NO_TIMEOUT) !=
RTEMS_SUCCESSFUL) {
/* Can't start a TM_recv if another TM_recv of TM_recv_block is
in progress */
DBG("ASCS_TM_recv: Could not obtain semaphore, transaction probably in progress\n");
return -GRASCS_ERROR_TRANSACTIVE;
}
if(!cfg->running) {
/* Can't start a TM if serial interface isn't started */
DBG("ASCS_TM_recv: Serial interface is not started\n");
retval = -GRASCS_ERROR_STARTSTOP;
}
else {
/* Start transfer */
cfg->tmwords = 1;
cfg->tmptr = (int)word;
cfg->regs->cmd |= GRASCS_CMD_SENDTM;
/* Wait until transfer finishes */
rtems_semaphore_obtain(cfg->tmsem2,RTEMS_WAIT,RTEMS_NO_TIMEOUT);
retval = 0;
}
rtems_semaphore_release(cfg->tmsem1);
return retval;
}
/* Function: ASCS_TM_recv_block
Arguments: block: Pointer to where the received datablock
should be stored.
ntrans: Number of transfers needed to transfer
the block.
Return values: 0 if successful, -GRASCS_ERROR_STARTSTOP if serial
interface isn't started, -GRASCS_ERROR_TRANSACTIVE if
a performed TM hasn't been processed yet
Description: Starts ntrans TMs and stores the data at the address
that block points to. The size of each transaction
will vary depending on whether the core is
configured for 8, 16, or 32 bits data transfers.
*/
int ASCS_TM_recv_block(int *block, int ntrans) {
int retval;
if(rtems_semaphore_obtain(cfg->tmsem1,RTEMS_NO_WAIT,RTEMS_NO_TIMEOUT) !=
RTEMS_SUCCESSFUL) {
/* Can't start a TM_recv_block if another TM_recv of TM_recv_block is
in progress */
DBG("ASCS_TM_recv_block: Could not obtain semaphore, transaction probably in progress\n");
return -GRASCS_ERROR_TRANSACTIVE;
}
if(!cfg->running) {
/* Can't start a TM if serial interface isn't started */
DBG("ASCS_TM_recv_block: Serial interface is not started\n");
retval = -GRASCS_ERROR_STARTSTOP;
}
else {
/* Start transfer */
cfg->tmwords = ntrans;
cfg->tmptr = (int)block;
cfg->regs->cmd |= GRASCS_CMD_SENDTM;
/* Wait until transfer finishes */
rtems_semaphore_obtain(cfg->tmsem2,RTEMS_WAIT,RTEMS_NO_TIMEOUT);
retval = 0;
}
rtems_semaphore_release(cfg->tmsem1);
return retval;
}
