GADC implementation with demo program

Also includes driver for AT91SAM7 cpu

4 files changed, 231 insertions, 0 deletions

diff --git a/drivers/gadc/AT91SAM7/gadc_lld.c b/drivers/gadc/AT91SAM7/gadc_lld.c
new file mode 100644
index 00000000..4b3c6cae
--- /dev/null
+++ b/drivers/gadc/AT91SAM7/gadc_lld.c
@@ -0,0 +1,102 @@
+/*
+    ChibiOS/GFX - Copyright (C) 2012, 2013
+                 Joel Bodenmann aka Tectu <joel@unormal.org>
+
+    This file is part of ChibiOS/GFX.
+
+    ChibiOS/GFX 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/GFX 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    include/gadc/lld/gadc_lld.c
+ * @brief   GADC - Periodic ADC driver source file for the AT91SAM7 cpu.
+ *
+ * @defgroup Driver Driver
+ * @ingroup GADC
+ * @{
+ */
+
+#include "ch.h"
+#include "hal.h"
+#include "gfx.h"
+
+#if GFX_USE_GADC
+
+#include "gadc/lld/gadc_lld.h"
+
+static ADCConversionGroup acg = {
+		FALSE,					// circular
+		1,						// num_channels
+		GADC_ISR_CompleteI,		// end_cb
+		GADC_ISR_ErrorI,		// error_cb
+		0,						// channelselects
+		0,						// trigger
+		0,						// frequency
+		};
+
+void gadc_lld_init(void) {
+	adcStart(&ADCD1, NULL);
+}
+
+size_t gadc_lld_samples_per_conversion(uint32_t physdev) {
+	size_t	cnt;
+	int		i;
+
+	/* The AT91SAM7 has AD0..7 - physdev is a bitmap of those channels */
+	for(cnt = 0, i = 0; i < 8; i++, physdev >>= 1)
+		if (physdev & 0x01)
+			cnt++;
+	return cnt;
+}
+
+void gadc_lld_start_timer(uint32_t physdev, uint32_t frequency) {
+	(void) physdev;
+	/**
+	 * The AT91SAM7 ADC driver supports triggering the ADC using a timer without having to implement
+	 * an interrupt handler for the timer. The driver also initialises the timer correctly for us.
+	 * Because we aren't trapping the interrupt ourselves we can't increment GADC_Timer_Missed if an
+	 * interrupt is missed.
+	 */
+	acg.frequency = frequency;
+}
+
+void gadc_lld_stop_timer(uint32_t physdev) {
+	(void) physdev;
+	if ((acg.trigger & ~ADC_TRIGGER_SOFTWARE) == ADC_TRIGGER_TIMER)
+		adcStop(&ADCD1);
+}
+
+void gadc_lld_adc_timerI(GadcLldTimerData *pgtd) {
+	/**
+	 *  We don't need to calculate num_channels because the AT91SAM7 ADC does this for us.
+	 */
+	acg.channelselects = pgtd->physdev;
+	acg.trigger = pgtd->now ? (ADC_TRIGGER_TIMER|ADC_TRIGGER_SOFTWARE) : ADC_TRIGGER_TIMER;
+
+	adcStartConversionI(&ADCD1, &acg, pgtd->buffer, pgtd->count);
+
+	/* Next time assume the same (still running) timer */
+	acg.frequency = 0;
+}
+
+void gadc_lld_adc_nontimerI(GadcLldNonTimerData *pgntd) {
+	/**
+	 *  We don't need to calculate num_channels because the AT91SAM7 ADC does this for us.
+	 */
+	acg.channelselects = pgntd->physdev;
+	acg.trigger = ADC_TRIGGER_SOFTWARE;
+	adcStartConversionI(&ADCD1, &acg, pgntd->buffer, 1);
+}
+
+#endif /* GFX_USE_GADC */
+/** @} */
diff --git a/drivers/gadc/AT91SAM7/gadc_lld.mk b/drivers/gadc/AT91SAM7/gadc_lld.mk
new file mode 100644
index 00000000..001d44b1
--- /dev/null
+++ b/drivers/gadc/AT91SAM7/gadc_lld.mk
@@ -0,0 +1,5 @@
+# List the required driver.
+GFXSRC += $(GFXLIB)/drivers/gadc/AT91SAM7/gadc_lld.c
+
+# Required include directories
+GFXINC += $(GFXLIB)/drivers/gadc/AT91SAM7
diff --git a/drivers/gadc/AT91SAM7/gadc_lld_board_olimexsam7ex256.h b/drivers/gadc/AT91SAM7/gadc_lld_board_olimexsam7ex256.h
new file mode 100644
index 00000000..6f23db17
--- /dev/null
+++ b/drivers/gadc/AT91SAM7/gadc_lld_board_olimexsam7ex256.h
@@ -0,0 +1,46 @@
+/*
+    ChibiOS/GFX - Copyright (C) 2012, 2013
+                 Joel Bodenmann aka Tectu <joel@unormal.org>
+
+    This file is part of ChibiOS/GFX.
+
+    ChibiOS/GFX 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/GFX 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    drivers/gadc/AT91SAM7/gadc_lld_board_olimexsam7ex256.h
+ * @brief   GADC Driver config file.
+ *
+ * @addtogroup GADC
+ * @{
+ */
+
+#ifndef _GADC_LLD_BOARD_OLIMEXSAM7EX256_H
+#define _GADC_LLD_BOARD_OLIMEXSAM7EX256_H
+
+#if GFX_USE_GADC
+
+/*===========================================================================*/
+/* Analogue devices on this board                                            */
+/*===========================================================================*/
+
+#define GADC_PHYSDEV_MICROPHONE			0x00000080
+#define GADC_PHYSDEV_DIAL				0x00000040
+#define GADC_PHYSDEV_TEMPERATURE		0x00000020
+
+#endif	/* GFX_USE_GADC */
+
+#endif	/* _GADC_LLD_BOARD_OLIMEXSAM7EX256_H */
+/** @} */
+
diff --git a/drivers/gadc/AT91SAM7/gadc_lld_config.h b/drivers/gadc/AT91SAM7/gadc_lld_config.h
new file mode 100644
index 00000000..882573c8
--- /dev/null
+++ b/drivers/gadc/AT91SAM7/gadc_lld_config.h
@@ -0,0 +1,78 @@
+/*
+    ChibiOS/GFX - Copyright (C) 2012, 2013
+                 Joel Bodenmann aka Tectu <joel@unormal.org>
+
+    This file is part of ChibiOS/GFX.
+
+    ChibiOS/GFX 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/GFX 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    drivers/gadc/AT91SAM7/gadc_lld_config.h
+ * @brief   GADC Driver config file.
+ *
+ * @addtogroup GADC
+ * @{
+ */
+
+#ifndef GADC_LLD_CONFIG_H
+#define GADC_LLD_CONFIG_H
+
+#if GFX_USE_GADC
+
+/*===========================================================================*/
+/* Driver hardware support.                                                  */
+/*===========================================================================*/
+
+/**
+ * @brief	ChibiOS has a nasty bug in its _adc_isr_full_code() routine (defined in adc.h as a macro).
+ * 			Do we have the version of ChibiOS with this bug.
+ * @detail	Set to TRUE if ChibiOS has this bug.
+ * @note	Fixed in ChibiOS 2.4.4stable and 2.5.2unstable (and the repository from 18th Feb 2013)
+ * @note	This bug prevents us re-calling adcStartConversionI() from with the ISR even though
+ * 			it is clearly designed to handle it. For some reason (on this micro) the high speed timer
+ * 			is not affected only the single sample low speed timer. In that situation we wait until
+ * 			we get back to thread land. This is terrible for the accuracy of the high speed timer
+ * 			but what can we do (other than fix the bug).
+ * @note	For the AT91SAM7 ADC driver, it post-dates the finding of the bug so we safely
+ * 			say that the bug doesn't exist for this driver.
+ */
+#define ADC_ISR_FULL_CODE_BUG				FALSE
+
+/**
+ * @brief	The maximum sample frequency supported by this CPU
+ */
+#define GADC_MAX_SAMPLE_FREQUENCY			132000
+
+/**
+ * @brief	The number of bits in a sample
+ */
+#define GADC_BITS_PER_SAMPLE				AT91_ADC1_RESOLUTION
+
+/* Pull in board specific defines */
+#if defined(GADC_USE_CUSTOM_BOARD) && GADC_USE_CUSTOM_BOARD
+	/* Include the user supplied board definitions */
+	#include "gadc_lld_board.h"
+#elif defined(BOARD_OLIMEX_SAM7_EX256)
+	#include "gadc_lld_board_olimexsam7ex256.h"
+#else
+	/* Include the user supplied board definitions */
+	#include "gadc_lld_board.h"
+#endif
+
+#endif	/* GFX_USE_GADC */
+
+#endif	/* _GDISP_LLD_CONFIG_H */
+/** @} */
+