1 /*******************************************************************************
2 * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
4 * Permission is hereby granted, free of charge, to any person obtaining a
5 * copy of this software and associated documentation files (the "Software"),
6 * to deal in the Software without restriction, including without limitation
7 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
8 * and/or sell copies of the Software, and to permit persons to whom the
9 * Software is furnished to do so, subject to the following conditions:
11 * The above copyright notice and this permission notice shall be included
12 * in all copies or substantial portions of the Software.
14 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
15 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
16 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
17 * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
18 * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
19 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
20 * OTHER DEALINGS IN THE SOFTWARE.
22 * Except as contained in this notice, the name of Maxim Integrated
23 * Products, Inc. shall not be used except as stated in the Maxim Integrated
24 * Products, Inc. Branding Policy.
26 * The mere transfer of this software does not imply any licenses
27 * of trade secrets, proprietary technology, copyrights, patents,
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29 * property whatsoever. Maxim Integrated Products, Inc. retains all
31 *******************************************************************************
34 #include "mbed_assert.h"
35 #include "analogin_api.h"
36 #include "clkman_regs.h"
37 #include "pwrman_regs.h"
39 #include "PeripheralPins.h"
41 #define PGA_TRK_CNT 0x1F
42 #define ADC_ACT_CNT 0x1
43 #define ADC_PGA_CNT 0x1
44 #define ADC_ACQ_CNT 0x1
45 #define ADC_SLP_CNT 0x1
47 //******************************************************************************
48 void analogin_init(analogin_t
*obj
, PinName pin
)
50 // Make sure pin is an analog pin we can use for ADC
51 MBED_ASSERT((ADCName
)pinmap_peripheral(pin
, PinMap_ADC
) != (ADCName
)NC
);
53 // Set the object pointer
55 obj
->adccfg
= MXC_ADCCFG
;
56 obj
->adc_fifo
= MXC_ADC_FIFO
;
59 // Set the ADC clock to the system clock frequency
60 MXC_SET_FIELD(&MXC_CLKMAN
->clk_ctrl
, MXC_F_CLKMAN_CLK_CTRL_ADC_SOURCE_SELECT
,
61 (MXC_F_CLKMAN_CLK_CTRL_ADC_GATE_N
| (MXC_E_CLKMAN_ADC_SOURCE_SELECT_SYSTEM
<<
62 MXC_F_CLKMAN_CLK_CTRL_ADC_SOURCE_SELECT_POS
)));
65 MXC_PWRMAN
->pwr_rst_ctrl
|= MXC_F_PWRMAN_PWR_RST_CTRL_AFE_POWERED
;
67 // Setup and hold window
68 MXC_SET_FIELD(&obj
->adc
->tg_ctrl0
, MXC_F_ADC_TG_CTRL0_PGA_TRK_CNT
, PGA_TRK_CNT
);
70 // Setup sampling count and timing
71 MXC_SET_FIELD(&obj
->adc
->tg_ctrl1
, (MXC_F_ADC_TG_CTRL1_PGA_ACQ_CNT
|
72 MXC_F_ADC_TG_CTRL1_ADC_ACQ_CNT
| MXC_F_ADC_TG_CTRL1_ADC_SLP_CNT
),
73 ((ADC_PGA_CNT
<< MXC_F_ADC_TG_CTRL1_PGA_ACQ_CNT_POS
) |
74 (ADC_ACQ_CNT
<< MXC_F_ADC_TG_CTRL1_ADC_ACQ_CNT_POS
) |
75 (ADC_SLP_CNT
<< MXC_F_ADC_TG_CTRL1_ADC_SLP_CNT_POS
) |
76 (MXC_F_ADC_TG_CTRL1_ADC_BRST_CNT
)));
79 //******************************************************************************
80 float analogin_read(analogin_t
*obj
)
82 // Convert integer to float
83 return (((float)analogin_read_u16(obj
)/(float)0xFFFF));
86 //******************************************************************************
87 uint16_t analogin_read_u16(analogin_t
*obj
)
89 // Set the pin to take readings from
92 if(obj
->adc_pin
>> PORT_SHIFT
== 0xB) {
93 mux_pos
= (obj
->adc_pin
& 0xF) + 8;
95 mux_pos
= (obj
->adc_pin
& 0xF);
98 if(obj
->adc_pin
>> PORT_SHIFT
== 0xC) {
100 mux_pos
= (obj
->adc_pin
& 0xF) + 8;
104 obj
->adc
->ctrl0
|= MXC_F_ADC_CTRL0_CPU_ADC_RST
;
107 obj
->adc
->ctrl0
|= MXC_F_ADC_CTRL0_CPU_ADC_EN
;
109 // Setup the ADC clock
110 MXC_SET_FIELD(&obj
->adc
->ctrl0
, (MXC_F_ADC_CTRL0_ADC_MODE
| MXC_F_ADC_CTRL0_AVG_MODE
|
111 MXC_F_ADC_CTRL0_ADC_CLK_MODE
| MXC_F_ADC_CTRL0_ADC_BI_POL
),
112 ((MXC_E_ADC_MODE_SMPLCNT_FULL_RATE
<< MXC_F_ADC_CTRL0_ADC_MODE_POS
) |
113 (MXC_E_ADC_AVG_MODE_FILTER_OUTPUT
<< MXC_F_ADC_CTRL0_AVG_MODE_POS
) |
114 (0x2 << MXC_F_ADC_CTRL0_ADC_CLK_MODE_POS
) |
115 MXC_F_ADC_CTRL0_ADC_CLK_EN
));
117 // Setup the input multiplexor
118 MXC_SET_FIELD(&obj
->adc
->pga_ctrl
, (MXC_F_ADC_PGA_CTRL_MUX_CH_SEL
|
119 MXC_F_ADC_PGA_CTRL_MUX_DIFF
| MXC_F_ADC_PGA_CTRL_PGA_GAIN
),
120 ((mux_pos
<< MXC_F_ADC_PGA_CTRL_MUX_CH_SEL_POS
) |
121 (diff
<< MXC_F_ADC_PGA_CTRL_MUX_DIFF_POS
)));
123 // Setup voltage reference
124 MXC_SET_FIELD(&MXC_AFE
->ctrl1
, MXC_F_AFE_CTRL1_REF_ADC_VOLT_SEL
,
125 (MXC_F_AFE_CTRL1_REF_ADC_POWERUP
| MXC_F_AFE_CTRL1_REF_BLK_POWERUP
|
126 (MXC_E_AFE_REF_VOLT_SEL_1500
<< MXC_F_AFE_CTRL1_REF_ADC_VOLT_SEL_POS
)));
128 // Clear the done bit
129 obj
->adc
->intr
= MXC_F_ADC_INTR_DONE_IF
;
132 obj
->adc
->tg_ctrl0
|= (1 << MXC_F_ADC_TG_CTRL0_ADC_SMPL_CNT_POS
);
134 // Set the start bit to take the sample
135 obj
->adc
->ctrl0
|= MXC_F_ADC_CTRL0_CPU_ADC_START
;
137 // Wait for the conversion to complete
138 while(!(obj
->adc
->intr
& MXC_F_ADC_INTR_DONE_IF
)) {}
140 // Get sample from the fifo
141 uint16_t sample
= (uint16_t)(obj
->adc
->out
& 0xFFFF);
144 obj
->adc
->ctrl0
&= ~MXC_F_ADC_CTRL0_CPU_ADC_EN
;