Diff: targets/TARGET_Maxim/TARGET_MAX32600/analogin_api.c

Revision:

0:f269e3021894

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/targets/TARGET_Maxim/TARGET_MAX32600/analogin_api.c	Sun Oct 23 15:10:02 2016 +0000
@@ -0,0 +1,147 @@
+/*******************************************************************************
+ * Copyright (C) 2015 Maxim Integrated Products, Inc., All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included
+ * in all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+ * IN NO EVENT SHALL MAXIM INTEGRATED BE LIABLE FOR ANY CLAIM, DAMAGES
+ * OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Except as contained in this notice, the name of Maxim Integrated
+ * Products, Inc. shall not be used except as stated in the Maxim Integrated
+ * Products, Inc. Branding Policy.
+ *
+ * The mere transfer of this software does not imply any licenses
+ * of trade secrets, proprietary technology, copyrights, patents,
+ * trademarks, maskwork rights, or any other form of intellectual
+ * property whatsoever. Maxim Integrated Products, Inc. retains all
+ * ownership rights.
+ *******************************************************************************
+ */
+
+#include "mbed_assert.h"
+#include "analogin_api.h"
+#include "clkman_regs.h"
+#include "pwrman_regs.h"
+#include "afe_regs.h"
+#include "PeripheralPins.h"
+
+#define PGA_TRK_CNT     0x1F
+#define ADC_ACT_CNT     0x1
+#define ADC_PGA_CNT     0x1
+#define ADC_ACQ_CNT     0x1
+#define ADC_SLP_CNT     0x1
+ 
+//******************************************************************************
+void analogin_init(analogin_t *obj, PinName pin)
+{
+    // Make sure pin is an analog pin we can use for ADC
+    MBED_ASSERT((ADCName)pinmap_peripheral(pin, PinMap_ADC) != (ADCName)NC);
+
+    // Set the object pointer
+    obj->adc = MXC_ADC;
+    obj->adccfg = MXC_ADCCFG;
+    obj->adc_fifo = MXC_ADC_FIFO;
+    obj->adc_pin = pin;
+
+    // Set the ADC clock to the system clock frequency
+    MXC_SET_FIELD(&MXC_CLKMAN->clk_ctrl, MXC_F_CLKMAN_CLK_CTRL_ADC_SOURCE_SELECT,
+        (MXC_F_CLKMAN_CLK_CTRL_ADC_GATE_N | (MXC_E_CLKMAN_ADC_SOURCE_SELECT_SYSTEM << 
+        MXC_F_CLKMAN_CLK_CTRL_ADC_SOURCE_SELECT_POS)));
+
+    // Enable AFE power
+    MXC_PWRMAN->pwr_rst_ctrl |= MXC_F_PWRMAN_PWR_RST_CTRL_AFE_POWERED;
+
+    // Setup and hold window
+    MXC_SET_FIELD(&obj->adc->tg_ctrl0, MXC_F_ADC_TG_CTRL0_PGA_TRK_CNT, PGA_TRK_CNT);
+
+    // Setup sampling count and timing
+    MXC_SET_FIELD(&obj->adc->tg_ctrl1, (MXC_F_ADC_TG_CTRL1_PGA_ACQ_CNT | 
+        MXC_F_ADC_TG_CTRL1_ADC_ACQ_CNT | MXC_F_ADC_TG_CTRL1_ADC_SLP_CNT),
+        ((ADC_PGA_CNT << MXC_F_ADC_TG_CTRL1_PGA_ACQ_CNT_POS) | 
+        (ADC_ACQ_CNT << MXC_F_ADC_TG_CTRL1_ADC_ACQ_CNT_POS) |
+        (ADC_SLP_CNT << MXC_F_ADC_TG_CTRL1_ADC_SLP_CNT_POS) |
+        (MXC_F_ADC_TG_CTRL1_ADC_BRST_CNT)));
+}
+
+//******************************************************************************
+float analogin_read(analogin_t *obj)
+{
+    // Convert integer to float
+    return (((float)analogin_read_u16(obj)/(float)0xFFFF));
+}
+
+//******************************************************************************
+uint16_t analogin_read_u16(analogin_t *obj)
+{
+    // Set the pin to take readings from
+    unsigned mux_pos;
+    unsigned diff = 0;
+    if(obj->adc_pin >> PORT_SHIFT == 0xB) {
+        mux_pos = (obj->adc_pin & 0xF) + 8;
+    } else {
+        mux_pos = (obj->adc_pin & 0xF);
+    }
+
+    if(obj->adc_pin >> PORT_SHIFT == 0xC) {
+        diff = 1;
+        mux_pos = (obj->adc_pin & 0xF) + 8;
+    }
+
+    // Reset the ADC
+    obj->adc->ctrl0 |= MXC_F_ADC_CTRL0_CPU_ADC_RST;
+
+    // Enable the ADC
+    obj->adc->ctrl0 |= MXC_F_ADC_CTRL0_CPU_ADC_EN;
+
+    // Setup the ADC clock
+    MXC_SET_FIELD(&obj->adc->ctrl0, (MXC_F_ADC_CTRL0_ADC_MODE | MXC_F_ADC_CTRL0_AVG_MODE |
+        MXC_F_ADC_CTRL0_ADC_CLK_MODE | MXC_F_ADC_CTRL0_ADC_BI_POL),
+        ((MXC_E_ADC_MODE_SMPLCNT_FULL_RATE << MXC_F_ADC_CTRL0_ADC_MODE_POS) | 
+        (MXC_E_ADC_AVG_MODE_FILTER_OUTPUT << MXC_F_ADC_CTRL0_AVG_MODE_POS) |
+        (0x2 << MXC_F_ADC_CTRL0_ADC_CLK_MODE_POS) |
+        MXC_F_ADC_CTRL0_ADC_CLK_EN));
+
+    // Setup the input multiplexor
+    MXC_SET_FIELD(&obj->adc->pga_ctrl, (MXC_F_ADC_PGA_CTRL_MUX_CH_SEL | 
+        MXC_F_ADC_PGA_CTRL_MUX_DIFF | MXC_F_ADC_PGA_CTRL_PGA_GAIN),
+        ((mux_pos << MXC_F_ADC_PGA_CTRL_MUX_CH_SEL_POS) |
+        (diff << MXC_F_ADC_PGA_CTRL_MUX_DIFF_POS)));
+
+    // Setup voltage reference
+    MXC_SET_FIELD(&MXC_AFE->ctrl1, MXC_F_AFE_CTRL1_REF_ADC_VOLT_SEL, 
+        (MXC_F_AFE_CTRL1_REF_ADC_POWERUP | MXC_F_AFE_CTRL1_REF_BLK_POWERUP |
+        (MXC_E_AFE_REF_VOLT_SEL_1500 << MXC_F_AFE_CTRL1_REF_ADC_VOLT_SEL_POS)));
+
+    // Clear the done bit
+    obj->adc->intr = MXC_F_ADC_INTR_DONE_IF;
+
+    // Take one sample
+    obj->adc->tg_ctrl0 |= (1 << MXC_F_ADC_TG_CTRL0_ADC_SMPL_CNT_POS);
+
+    // Set the start bit to take the sample
+    obj->adc->ctrl0 |= MXC_F_ADC_CTRL0_CPU_ADC_START;
+
+    // Wait for the conversion to complete
+    while(!(obj->adc->intr & MXC_F_ADC_INTR_DONE_IF)) {}
+
+    // Get sample from the fifo
+    uint16_t sample = (uint16_t)(obj->adc->out & 0xFFFF);
+    
+    // Disable ADC
+    obj->adc->ctrl0 &= ~MXC_F_ADC_CTRL0_CPU_ADC_EN;
+
+    return (sample - 1);
+}