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/*
ChibiOS/RT - Copyright (C) 2006-2007 Giovanni Di Sirio.
This file is part of ChibiOS/RT.
ChibiOS/RT 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 3 of the License, or
(at your option) any later version.
ChibiOS/RT 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, see <http://www.gnu.org/licenses/>.
*/
#include <ch.h>
#include "lpc214x.h"
#include "lpc214x_ssp.h"
static BYTE8 *ip, *op;
static int icnt, ocnt;
static t_sspnotify callback;
static void *cbpar;
void SSPIrq(void) {
SSP *ssp = SSPBase;
BYTE8 b;
while (ssp->SSP_MIS & (MIS_ROR | MIS_RT | MIS_RX | MIS_TX)) {
if (ssp->SSP_MIS & MIS_ROR)
chSysHalt();
if (ssp->SSP_MIS & (MIS_RX | MIS_RT)) {
ssp->SSP_ICR = ICR_RT;
while (ssp->SSP_SR & SR_RNE) {
b = ssp->SSP_DR;
if (ip)
*ip++ = b;
icnt--;
}
if (icnt <= 0) { /* It should never become less than zero */
t_sspnotify fn = callback;
callback = NULL;
ssp->SSP_IMSC = 0;
VICVectAddr = 0;
fn(cbpar);
return;
}
continue;
}
/* It is MIS_TX, no need to test it again. */
while (ocnt && (ssp->SSP_SR & SR_TNF)) {
if (op)
ssp->SSP_DR = *op++;
else
ssp->SSP_DR = 0xFF;
ocnt--;
}
if (!ocnt)
ssp->SSP_IMSC = IMSC_ROR | IMSC_RT | IMSC_RX;
}
VICVectAddr = 0;
}
/*
* Starts an asynchronous SSP transfer.
* @param in pointer to the incoming data buffer, if this parameter is set to
* \p NULL then the incoming data is discarded.
* @param out pointer to the outgoing data buffer, if this parameter is set to
* \p NULL then 0xFF bytes will be output.
* @param n the number of bytes to be transferred
* @param fn callback function invoked when the operation is done
* @param par parameter to be passed to the callback function
* @return \p SSP_OK if the trasfer was started else \p SSP_RUNNING if a
* an operation was already started
*/
t_msg sspRWI(BYTE8 *in, BYTE8 *out, t_size n, t_sspnotify fn, void *par) {
if (callback)
return SSP_RUNNING;
callback = fn, cbpar = par, ip = in, op = out, icnt = ocnt = n;
SSPIMSC = IMSC_ROR | IMSC_RT | IMSC_RX | IMSC_TX;
return SSP_OK;
}
static void done(void *tp) {
chThdResumeI(tp);
}
/*
* Synchronous SSP transfer.
* @param in pointer to the incoming data buffer, if this parameter is set to
* \p NULL then the incoming data is discarded.
* @param out pointer to the outgoing data buffer, if this parameter is set to
* \p NULL then 0xFF bytes will be output.
* @param n the number of bytes to be transferred
* @return \p SSP_OK if the trasfer was performed else \p SSP_RUNNING if a
* an operation was already started
*/
t_msg sspRW(BYTE8 *in, BYTE8 *out, t_size n) {
chSysLock();
t_msg sts = sspRWI(in, out, n, done, chThdSelf());
if (sts == SSP_OK)
chSchGoSleepS(PRSUSPENDED);
chSysUnlock();
return sts;
}
/*
* Checks if a SSP operation is running.
* @return \p TRUE if an asynchronous operation is already running.
*/
BOOL sspIsRunningI(void) {
return callback != NULL;
}
/*
* SSP setup, must be invoked with interrupts disabled.
* Do not invoke while an operation is in progress.
*/
void SetSSPI(int cpsr, int cr0, int cr1) {
SSP *ssp = SSPBase;
ssp->SSP_CR1 = cr1 & ~CR1_SSE;
ssp->SSP_CR0 = cr0;
ssp->SSP_CPSR = cpsr;
ssp->SSP_CR1 = cr1 | CR1_SSE;
}
/*
* SSP subsystem initialization.
*/
void InitSSP(void) {
/* Enables the SPI1 clock */
PCONP = (PCONP & PCALL) | PCSPI1;
/* Clock = PCLK / 2 */
SetSSPI(2, CR0_DSS8BIT | CR0_FRFSPI | CR0_CLOCKRATE(0), 0);
VICIntEnable = INTMASK(SOURCE_SPI1);
}
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