1 /*****************************************************************************
2 *
3 * \file
4 *
5 * \brief ADC driver for AVR UC3.
6 *
7 * This file defines a useful set of functions for ADC on AVR UC3 devices.
8 *
9 * Copyright (c) 2009-2018 Microchip Technology Inc. and its subsidiaries.
10 *
11 * \asf_license_start
12 *
13 * \page License
14 *
15 * Subject to your compliance with these terms, you may use Microchip
16 * software and any derivatives exclusively with Microchip products.
17 * It is your responsibility to comply with third party license terms applicable
18 * to your use of third party software (including open source software) that
19 * may accompany Microchip software.
20 *
21 * THIS SOFTWARE IS SUPPLIED BY MICROCHIP "AS IS". NO WARRANTIES,
22 * WHETHER EXPRESS, IMPLIED OR STATUTORY, APPLY TO THIS SOFTWARE,
23 * INCLUDING ANY IMPLIED WARRANTIES OF NON-INFRINGEMENT, MERCHANTABILITY,
24 * AND FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT WILL MICROCHIP BE
25 * LIABLE FOR ANY INDIRECT, SPECIAL, PUNITIVE, INCIDENTAL OR CONSEQUENTIAL
26 * LOSS, DAMAGE, COST OR EXPENSE OF ANY KIND WHATSOEVER RELATED TO THE
27 * SOFTWARE, HOWEVER CAUSED, EVEN IF MICROCHIP HAS BEEN ADVISED OF THE
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29 * ALLOWED BY LAW, MICROCHIP'S TOTAL LIABILITY ON ALL CLAIMS IN ANY WAY
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31 * THAT YOU HAVE PAID DIRECTLY TO MICROCHIP FOR THIS SOFTWARE.
32 *
33 * \asf_license_stop
34 *
35 *****************************************************************************/
36 /*
37 * Support and FAQ: visit <a href="https://www.microchip.com/support/">Microchip Support</a>
38 */
39
40 #include <avr32/io.h>
41 #include "compiler.h"
42 #include "adc.h"
43
44 /** \brief Configure ADC. Mandatory to call.
45 * If not called, ADC channels will have side effects
46 *
47 * \param *adc Base address of the ADC
48 */
adc_configure(volatile avr32_adc_t * adc)49 void adc_configure(volatile avr32_adc_t *adc)
50 {
51 Assert( adc != NULL );
52
53 #ifdef USE_ADC_8_BITS
54 adc->mr |= 1 << AVR32_ADC_LOWRES_OFFSET;
55 #endif
56
57 /* Set Sample/Hold time to max so that the ADC capacitor should be
58 * loaded entirely */
59 adc->mr |= 0xF << AVR32_ADC_SHTIM_OFFSET;
60
61 /* Set Startup to max so that the ADC capacitor should be loaded
62 * entirely */
63 adc->mr |= 0x1F << AVR32_ADC_STARTUP_OFFSET;
64 }
65
66 /** \brief Start analog to digital conversion
67 * \param *adc Base address of the ADC
68 */
adc_start(volatile avr32_adc_t * adc)69 void adc_start(volatile avr32_adc_t *adc)
70 {
71 Assert( adc != NULL );
72
73 /* start conversion */
74 adc->cr = AVR32_ADC_START_MASK;
75 }
76
77 /** \brief Enable channel
78 *
79 * \param *adc Base address of the ADC
80 * \param channel channel to enable (0 to 7)
81 */
adc_enable(volatile avr32_adc_t * adc,uint16_t channel)82 void adc_enable(volatile avr32_adc_t *adc, uint16_t channel)
83 {
84 Assert( adc != NULL );
85 Assert( channel <= AVR32_ADC_CHANNELS_MSB ); /* check if channel exist
86 **/
87
88 /* enable channel */
89 adc->cher = (1 << channel);
90 }
91
92 /** \brief Disable channel
93 *
94 * \param *adc Base address of the ADC
95 * \param channel channel to disable (0 to 7)
96 */
adc_disable(volatile avr32_adc_t * adc,uint16_t channel)97 void adc_disable(volatile avr32_adc_t *adc, uint16_t channel)
98 {
99 Assert( adc != NULL );
100 Assert( channel <= AVR32_ADC_CHANNELS_MSB ); /* check if channel exist
101 **/
102
103 if (adc_get_status(adc, channel) == true) {
104 /* disable channel */
105 adc->chdr |= (1 << channel);
106 }
107 }
108
109 /** \brief Get channel 0 to 7 status
110 *
111 * \param *adc Base address of the ADC
112 * \param channel channel to handle (0 to 7)
113 * \return bool true if channel is enabled
114 * false if channel is disabled
115 */
adc_get_status(volatile avr32_adc_t * adc,uint16_t channel)116 bool adc_get_status(volatile avr32_adc_t *adc, uint16_t channel)
117 {
118 Assert( adc != NULL );
119 Assert( channel <= AVR32_ADC_CHANNELS_MSB ); /* check if channel exist
120 **/
121
122 return ((adc->chsr & (1 << channel)) ? true : false);
123 }
124
125 /** \brief Check channel conversion status
126 *
127 * \param *adc Base address of the ADC
128 * \param channel channel to check (0 to 7)
129 * \return bool true if conversion not running
130 * false if conversion running
131 */
adc_check_eoc(volatile avr32_adc_t * adc,uint16_t channel)132 bool adc_check_eoc(volatile avr32_adc_t *adc, uint16_t channel)
133 {
134 Assert( adc != NULL );
135 Assert( channel <= AVR32_ADC_CHANNELS_MSB ); /* check if channel exist
136 **/
137
138 /* get SR register : EOC bit for channel */
139 return ((adc->sr & (1 << channel)) ? true : false);
140 }
141
142 /** \brief Check channel conversion overrun error
143 *
144 * \param *adc Base address of the ADC
145 * \param channel channel to check (0 to 7)
146 * \return bool FAIL if an error occurred
147 * PASS if no error occurred
148 */
adc_check_ovr(volatile avr32_adc_t * adc,uint16_t channel)149 bool adc_check_ovr(volatile avr32_adc_t *adc, uint16_t channel)
150 {
151 Assert( adc != NULL );
152 Assert( channel <= AVR32_ADC_CHANNELS_MSB ); /* check if channel exist
153 **/
154
155 /* get SR register : OVR bit for channel */
156 return ((adc->sr & (1 << (channel + 8))) ? FAIL : PASS);
157 }
158
159 /** \brief Get channel value
160 *
161 * \param *adc Base address of the ADC
162 * \param channel channel to handle (0 to 7)
163 * \return The value acquired (unsigned long)
164 */
adc_get_value(volatile avr32_adc_t * adc,uint16_t channel)165 uint32_t adc_get_value(volatile avr32_adc_t *adc, uint16_t channel)
166 {
167 Assert( adc != NULL );
168 Assert( channel <= AVR32_ADC_CHANNELS_MSB );
169
170 /* wait for end of conversion */
171 while (adc_check_eoc(adc, channel) != true) {
172 }
173
174 return *((uint32_t *)((&(adc->cdr0)) + channel));
175 }
176
177 /** \brief Wait for the next converted data and return its value
178 *
179 * \param *adc Base address of the ADC
180 * \return The latest converted value (unsigned long)
181 */
adc_get_latest_value(volatile avr32_adc_t * adc)182 uint32_t adc_get_latest_value(volatile avr32_adc_t *adc)
183 {
184 Assert( adc != NULL );
185
186 /* Wait for the data ready flag */
187 while ((adc->sr & AVR32_ADC_DRDY_MASK) != AVR32_ADC_DRDY_MASK) {
188 }
189
190 return adc->lcdr;
191 }
192