From 16178e1c45a76544d34ce63db37932838353637c Mon Sep 17 00:00:00 2001
From: gdisirio <gdisirio@35acf78f-673a-0410-8e92-d51de3d6d3f4>
Date: Sat, 28 Nov 2009 12:25:35 +0000
Subject: git-svn-id: svn://svn.code.sf.net/p/chibios/svn/trunk@1333
 35acf78f-673a-0410-8e92-d51de3d6d3f4

---
 os/hal/platforms/LPC214x/lpc214x_ssp.c | 133 +++++++++++++++++++++++++++++++++
 1 file changed, 133 insertions(+)
 create mode 100644 os/hal/platforms/LPC214x/lpc214x_ssp.c

(limited to 'os/hal/platforms/LPC214x/lpc214x_ssp.c')

diff --git a/os/hal/platforms/LPC214x/lpc214x_ssp.c b/os/hal/platforms/LPC214x/lpc214x_ssp.c
new file mode 100644
index 000000000..af9915395
--- /dev/null
+++ b/os/hal/platforms/LPC214x/lpc214x_ssp.c
@@ -0,0 +1,133 @@
+/*
+    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/>.
+*/
+
+/**
+ * @file LPC214x/lpc214x_ssp.c
+ * @brief LPC214x SSP driver code.
+ * @addtogroup LPC214x_SSP
+ * @{
+ */
+
+#include <ch.h>
+#include <pal.h>
+
+#include "lpc214x.h"
+#include "lpc214x_ssp.h"
+
+#if LPC214x_SSP_USE_MUTEX
+static Semaphore me;
+#endif
+
+/**
+ * @brief Aquires access to the SSP bus.
+ * @note This function also handles the mutual exclusion on the SSP bus if
+ *       the @p LPC214x_SSP_USE_MUTEX option is enabled.
+ */
+void sspAcquireBus(void) {
+
+#if LPC214x_SSP_USE_MUTEX
+  chSemWait(&me);
+#endif
+  palClearPad(IOPORT1, 20);
+}
+
+/**
+ * @brief Releases the SSP bus.
+ * @note This function also handles the mutual exclusion on the SSP bus if
+ *       the @p LPC214x_SSP_USE_MUTEX option is enabled.
+ */
+void sspReleaseBus(void) {
+
+  palClearPad(IOPORT1, 20);
+#if LPC214x_SSP_USE_MUTEX
+  chSemSignal(&me);
+#endif
+}
+
+/**
+ * @brief Synchronous SSP transfer.
+ * @param[in] in pointer to the incoming data buffer, if this parameter is set
+ *               to @p NULL then the incoming data is discarded
+ * @param[out] out pointer to the outgoing data buffer, if this parameter is
+ *                 set to @p NULL then 0xFF bytes will be output
+ * @param[in] n the number of bytes to be transferred
+ * @note The transfer is performed in a software loop and is not interrupt
+ *       driven for performance reasons, this function should be invoked
+ *       by a low priority thread in order to "play nice" with the
+ *       rest of the system. This kind of peripheral would really need a
+ *       dedicated DMA channel.
+ */
+void sspRW(uint8_t *in, uint8_t *out, size_t n) {
+  int icnt, ocnt;
+
+  SSP *ssp = SSPBase;
+  icnt = ocnt = n;
+  while (icnt) {
+
+    if (ssp->SSP_SR & SR_RNE) {
+      if (in)
+        *in++ = ssp->SSP_DR;
+      else
+        ssp->SSP_DR;
+      icnt--;
+      continue; /* Priority over transmission. */
+    }
+
+    if (ocnt && (ssp->SSP_SR & SR_TNF)) {
+      if (out)
+        ssp->SSP_DR = *out++;
+      else
+        ssp->SSP_DR = 0xFF;
+      ocnt--;
+    }
+  }
+}
+
+/**
+ * @brief SSP setup.
+ * @param[in] cpsr the value for the @p CPSR register
+ * @param[in] cr0 the value for the @p CR0 register
+ * @param[in] cr1 the value for the @p CR1 register
+ */
+void ssp_setup(int cpsr, int cr0, int cr1) {
+
+  SSP *ssp = SSPBase;
+  ssp->SSP_CR1 = 0;
+  ssp->SSP_CR0 = cr0;
+  ssp->SSP_CPSR = cpsr;
+  ssp->SSP_CR1 = cr1 | CR1_SSE;
+}
+
+/**
+ * @brief SSP subsystem initialization.
+ */
+void ssp_init(void) {
+
+  /* Enables the SPI1 clock */
+  PCONP = (PCONP & PCALL) | PCSPI1;
+
+  /* Clock = PCLK / 2 (fastest). */
+  ssp_setup(2, CR0_DSS8BIT | CR0_FRFSPI | CR0_CLOCKRATE(0), 0);
+
+#if LPC214x_SSP_USE_MUTEX
+  chSemInit(&me, 1);
+#endif
+}
+
+/** @} */
-- 
cgit v1.2.3