hc32f460: Add support for hc32f460 micro-controllers

Signed-off-by: Steven Gotthardt <gotthardt@gmail.com>

src/hc32f460/adc.c

@@ -0,0 +1,155 @@
+// ADC functions on Huada HC32F460
+//
+// Copyright (C) 2022  Steven Gotthardt <gotthardt@gmail.com>
+//
+// This file may be distributed under the terms of the GNU GPLv3 license.
+
+#include "generic/misc.h"   // timer_from_us
+#include "command.h"        // shutdown
+#include "board/gpio.h"     // gpio_adc_setup
+#include "board/internal.h" // GPIO
+#include "sched.h"          // sched_shutdown
+
+// library
+#include "hc32f460_adc.h"
+#include "hc32f460_pwc.h"
+#include "hc32f460_gpio.h"
+
+#define ADC_RESOLUTION_12BIT        (12u)
+#define ADC_RESOLUTION_10BIT        (10u)
+#define ADC_RESOLUTION_8BIT         (8u)
+
+#define ADC1_RESOLUTION             (ADC_RESOLUTION_12BIT)
+#define ADC1_PRECISION              (1ul << ADC1_RESOLUTION)
+
+#if ADC1_RESOLUTION == ADC_RESOLUTION_12BIT
+#define AdcResolution   AdcResolution_12Bit
+#elif ADC1_RESOLUTION == ADC_RESOLUTION_10BIT
+#define AdcResolution   AdcResolution_10Bit
+#else
+#define AdcResolution   AdcResolution_8Bit
+#endif
+
+
+/* Timeout value definitions. Found in example code */
+#define TIMEOUT_VAL     (30u)
+
+DECL_CONSTANT("ADC_MAX", ADC1_PRECISION-1);
+
+// These pins can be used for ADC
+static const uint8_t adc_gpio[] = {
+    GPIO('A', 0),   // Chan 0
+    GPIO('A', 1),   // Chan 1
+    GPIO('A', 2),   // Chan 2
+    GPIO('A', 3),   // Chan 3
+    GPIO('A', 4),   // Chan 4
+    GPIO('A', 5),   // Chan 5
+    GPIO('A', 6),   // Chan 6
+    GPIO('A', 7),   // Chan 7
+    GPIO('B', 0),   // Chan 8
+    GPIO('B', 1),   // Chan 9
+    GPIO('C', 0),   // Chan 10  // TBed  on TriGorilla
+    GPIO('C', 1),   // Chan 11  // THead on TriGorilla
+    GPIO('C', 2),   // Chan 12
+    GPIO('C', 3),   // Chan 13
+    GPIO('C', 4),   // Chan 14  // TBed  on aquilla
+    GPIO('C', 5),   // Chan 15  // THead on aquilla
+};
+
+
+struct gpio_adc
+gpio_adc_setup(uint32_t gpio)
+{
+    // validate pin in adc_pins table
+    int chan;
+    for (chan=0; ; chan++)
+    {
+        if (chan >= ARRAY_SIZE(adc_gpio))
+        {
+            shutdown("Not a valid ADC pin");
+        }
+        if (adc_gpio[chan] == gpio)
+        {
+            break;
+        }
+    }
+
+    // set as analog
+    gpio_peripheral(gpio, Pin_Mode_Ana, 0);
+
+    uint8_t sampleTime[ARRAY_SIZE(adc_gpio)] = { TIMEOUT_VAL };   // all chans
+    stc_adc_ch_cfg_t stcAdcChan;
+    stcAdcChan.u32Channel   = 1 << chan;
+    stcAdcChan.u8Sequence   = ADC_SEQ_A;    // all conversions are in SEQ A
+    stcAdcChan.pu8SampTime  = sampleTime;
+    ADC_AddAdcChannel(M4_ADC1, &stcAdcChan);
+
+    return (struct gpio_adc){ .chan = chan };
+}
+
+
+// Try to sample a value. Returns zero if sample ready, otherwise
+// returns the number of clock ticks the caller should wait before
+// retrying this function.
+uint32_t
+gpio_adc_sample(struct gpio_adc g)
+{
+    // true if the sequence is finished
+    if (ADC_GetEocFlag(M4_ADC1, ADC_SEQ_A))
+    {
+         // all conversions are done - clear the flag
+        ADC_ClrEocFlag(M4_ADC1, ADC_SEQ_A);
+        return 0;
+    }
+    else if (M4_ADC1->STR & 1)
+    {
+        // running but not done yet
+        return timer_from_us(TIMEOUT_VAL/2);
+    }
+    else
+    {
+        // not running - so start
+        ADC_StartConvert(M4_ADC1);
+    }
+
+    return timer_from_us(TIMEOUT_VAL);
+}
+
+
+// Read a value; use only after gpio_adc_sample() returns zero
+uint16_t
+gpio_adc_read(struct gpio_adc g)
+{
+    // return the one we want...
+    return ADC_GetValue(M4_ADC1, g.chan);
+}
+
+
+// Cancel a sample that may have been started with gpio_adc_sample()
+void
+gpio_adc_cancel_sample(struct gpio_adc g)
+{
+    ADC_StopConvert(M4_ADC1);
+}
+
+
+// The clocks are already set by the loader.
+// There is ADC1 and ADC2. Sequences do all channels at once.
+void
+adc_init(void)
+{
+    //  PCLK2 (ADC clock) is 'divide by 4', Max ADC clock is 60MHz
+    stc_adc_init_t stcAdcInit = {0};
+    stcAdcInit.enResolution = AdcResolution;  // see define above
+    stcAdcInit.enDataAlign  = AdcDataAlign_Right;
+    stcAdcInit.enAutoClear  = AdcClren_Disable;
+    stcAdcInit.enScanMode   = AdcMode_SAOnce;
+
+    // power-on ADC
+    PWC_Fcg3PeriphClockCmd(PWC_FCG3_PERIPH_ADC1, Enable);
+
+    // only using ADC1
+    ADC_Init(M4_ADC1, &stcAdcInit);
+}
+
+DECL_INIT(adc_init);