Merge remote branch 'libmc1322x/master'

2011-03-11 16:28:14 -05:00 · 2011-03-11 16:28:14 -05:00 · 59d7fad746
commit 59d7fad746
parent abf6f1a153 c27e96f1e9
13 changed files with 1127 additions and 4 deletions
--- a/cpu/mc1322x/lib/adc.c
+++ b/cpu/mc1322x/lib/adc.c
@ -0,0 +1,138 @@
+/*
+ * Copyright (c) 2010, Mariano Alvira <mar@devl.org> and other contributors
+ * to the MC1322x project (http://mc1322x.devl.org)
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the Institute nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * This file is part of libmc1322x: see http://mc1322x.devl.org
+ * for details.
+ *
+ *
+ */
+
+#include <stdint.h>
+#include "crm.h"
+#include "adc.h"
+#include "gpio-util.h"
+
+//#define ADC_CHANS_ENABLED 0x3F // channels 0-5 enabled
+//#define ADC_CHANS_ENABLED 0x7E // channels 1-6 enabled
+//#define ADC_CHANS_ENABLED (1 << 6) // only channel 6 enabled
+#define ADC_CHANS_ENABLED 0x1FF // all channels, including battery reference voltage
+
+//#define ADC_PRESCALE_VALUE 24 // divide by 24 for 1MHz.
+
+#define ADC_SAMPLE_FREQ 400 // Hz (minimum of ~366.21 Hz)
+#define ADC_PRESCALE_VALUE (REF_OSC / ADC_SAMPLE_FREQ)
+
+#define ADC_USE_TIMER      0
+#define ADC_USE_INTERRUPTS 0 // incomplete support
+
+uint16_t adc_reading[NUM_ADC_CHAN];
+
+void ADC_flush(void) {
+	while(ADC->FIFO_STATUSbits.EMPTY == 0) ADC->FIFO_READ;
+}
+
+uint16_t ADC_READ(void) {
+	while(ADC->FIFO_STATUSbits.EMPTY); // loop while empty
+	return ADC->FIFO_READ; // upper 4 bits are channel number
+}
+
+
+void adc_service(void) {
+	uint16_t value;
+	uint8_t channel;
+	while (ADC->FIFO_STATUSbits.EMPTY == 0) {
+		value = ADC->FIFO_READ;
+		channel = value >> 12;
+		if (channel < NUM_ADC_CHAN) adc_reading[channel] = value & 0xFFF;
+	}
+}
+
+void adc_init(void) {
+	uint8_t n;
+
+	ADC->CLOCK_DIVIDER = 80;       // 300 KHz
+	ADC->PRESCALE      = ADC_PRESCALE_VALUE - 1;       // divide by 24 for 1MHz.
+
+	ADC->CONTROL       = 1;
+
+	// The ON-TIME must always be 10µs or greater - typical On-Time value = 0x000A (10dec)
+	ADC->ON_TIME       = 10;
+
+	/*
+	NOTE
+	The ADC analog block requires 6 ADC_Clocks per conversion, and the
+	ADC_Clock must 300kHz or less. With 6 clocks/conversion and a 33.33µs
+	clock period:
+	* The ADC convert time must always be 20µs or greater
+	* If the ADC_Clock is a frequency lower than 300kHz, the convert time
+	must always be 6 ADC_Clock periods or greater
+	* For override mode, extend convert time to 40µs minimum or greater
+	For the convert time:
+	* This delay is a function of the Prescale Clock (typically 1 MHz)
+	* The register must be initialized for proper operation
+	* For a 20µs convert time with 1MHz, value = 0x0014 (20dec)
+	* If convert time is insufficient, inaccurate sample data will result
+	*/
+	ADC->CONVERT_TIME  = 1000000 / (115200 / 8) - 1;
+
+	ADC->MODE          = 0;        // Automatic
+
+#if ADC_USE_INTERRUPTS
+	ADC->FIFO_CONTROL  = 7;
+#else
+	ADC->FIFO_CONTROL  = 0;
+#endif
+
+#if ADC_USE_TIMER
+	ADC->SR_1_HIGH       = 0x0000;
+	ADC->SR_1_LOW        = (REF_OSC / ADC_PRESCALE_VALUE) / (115200 / 8) + 1;
+#endif
+
+	ADC->SEQ_1         = 0
+#if ADC_USE_TIMER
+		| (1 << 15) // sequence based on Timer 1.
+#else
+		| (0 << 15) // sequence based on convert time.
+#endif
+		| ADC_CHANS_ENABLED;
+
+	ADC->CONTROL       = 0xF001
+//#if ADC_USE_TIMER
+		| (1 << 1) // Timer 1 enable
+//#endif
+	;
+	ADC->OVERRIDE     = (1 << 8);
+
+	for (n=0; n<=8; n++) {
+		if ((ADC_CHANS_ENABLED >> n) & 1) {
+			gpio_select_function(30 + n, 1); // Function 1 = ADC
+			gpio_set_pad_dir(30 + n, PAD_DIR_INPUT);
+		}
+	}
+}