Apollo3: Implement ADC

Author: multiplemonomials

hal/include/hal/spi_api.h

@@ -276,10 +276,14 @@ int  spi_master_write(spi_t *obj, int value);
  *
  *  The total number of bytes sent and received will be the maximum of
  *  tx_length and rx_length. The bytes written will be padded with the
- *  value 0xff.
+ *  write fill value.
  *
  * Note: Even if the word size / bits per frame is not 8, \c rx_length and \c tx_length
  * still give lengths in bytes of input data, not numbers of words.
+ * 
+ * Note: If \c tx_rx_buffers_equal_length is true in the capabilities structure, then either \c rx_length and \c tx_length
+ * must be the same, or one of them will be zero. If this is not the case than the HAL implementation should
+ * return an error.
  *
  * @param[in] obj        The SPI peripheral to use for sending
  * @param[in] tx_buffer  Pointer to the byte-array of data to write to the device
@@ -432,7 +436,7 @@ const PinMap *spi_slave_cs_pinmap(void);
  * @note On MCUs with a data cache, the return value is used to determine if a cache invalidation needs to be done
  * after the transfer is complete.  If this function returns true, the driver layer will cache invalidate the Rx buffer under
  * the assumption that the data needs to be re-read from main memory.  Be careful, because if the read was not actually
- * done by DMA, and the rx data is in the CPU cache, this invalidation will corrupt it.
+ * done by DMA, and the rx data is in the CPU cache and NOT main memory, this invalidation will corrupt it.
  *
  * @note The application layer will always acquire the SPI peripheral first before calling this, including setting the frequency and the bit width. So,
  *     the \c bit_width argument will never be different from the SPI's currently set bit width, and can actually be ignored.

targets/TARGET_Ambiq_Micro/TARGET_Apollo3/CMakeLists.txt

@@ -50,6 +50,7 @@ target_sources(mbed-apollo3
         device/spi_api.c
         device/us_ticker.c
         device/itm_api.c
+        device/analogin_api.c
 
         sdk/CMSIS/AmbiqMicro/Source/system_apollo3.c
 

targets/TARGET_Ambiq_Micro/TARGET_Apollo3/TARGET_SFE_ARTEMIS/PinNames.h

@@ -128,6 +128,9 @@ typedef enum
     SERIAL1_TX = IO_24,
     SERIAL1_RX = IO_25,
 
+    // Not a real pin on the device, but can be passed to AnalogIn to read the internal temperature sensor
+    ADC_TEMP = 0x10000,
+
     // Not connected
     NC = NC_VAL
 } PinName;

targets/TARGET_Ambiq_Micro/TARGET_Apollo3/TARGET_SFE_ARTEMIS_ATP/PinNames.h

@@ -164,6 +164,9 @@ typedef enum
     SERIAL1_TX = D24,
     SERIAL1_RX = D25,
 
+    // Not a real pin on the device, but can be passed to AnalogIn to read the internal temperature sensor
+    ADC_TEMP = 0x10000,
+
     // Not connected
     NC = NC_VAL
 } PinName;

targets/TARGET_Ambiq_Micro/TARGET_Apollo3/TARGET_SFE_ARTEMIS_DK/PinNames.h

@@ -134,6 +134,9 @@ typedef enum
     CONSOLE_TX = SERIAL_TX,
     CONSOLE_RX = SERIAL_RX,
 
+    // Not a real pin on the device, but can be passed to AnalogIn to read the internal temperature sensor
+    ADC_TEMP = 0x10000,
+
     // Not connected
     NC = NC_VAL
 } PinName;

targets/TARGET_Ambiq_Micro/TARGET_Apollo3/TARGET_SFE_ARTEMIS_MODULE/PinNames.h

@@ -97,6 +97,9 @@ typedef enum
     CONSOLE_TX = SERIAL_TX,
     CONSOLE_RX = SERIAL_RX,
 
+    // Not a real pin on the device, but can be passed to AnalogIn to read the internal temperature sensor
+    ADC_TEMP = 0x10000,
+
     // Not connected
     NC = NC_VAL
 } PinName;

targets/TARGET_Ambiq_Micro/TARGET_Apollo3/TARGET_SFE_ARTEMIS_NANO/PinNames.h

@@ -130,6 +130,9 @@ typedef enum
     SERIAL1_TX = D9,
     SERIAL1_RX = D10,
 
+    // Not a real pin on the device, but can be passed to AnalogIn to read the internal temperature sensor
+    ADC_TEMP = 0x10000,
+
     // Not connected
     NC = NC_VAL
 } PinName;

targets/TARGET_Ambiq_Micro/TARGET_Apollo3/TARGET_SFE_ARTEMIS_THING_PLUS/PinNames.h

@@ -137,6 +137,9 @@ typedef enum
     SERIAL1_TX = D1,
     SERIAL1_RX = D0,
 
+    // Not a real pin on the device, but can be passed to AnalogIn to read the internal temperature sensor
+    ADC_TEMP = 0x10000,
+
     // Not connected
     NC = NC_VAL
 } PinName;

targets/TARGET_Ambiq_Micro/TARGET_Apollo3/device/PeripheralNames.h

@@ -46,6 +46,9 @@ typedef enum {
     IOM_ANY
 } IOMName;
 
+// Each IOM can be used as an SPI
+#define DEVICE_SPI_COUNT 6
+
 typedef IOMName SPIName;
 typedef IOMName I2CName;
 

targets/TARGET_Ambiq_Micro/TARGET_Apollo3/device/PeripheralPins.c

@@ -17,13 +17,27 @@
 #include "PeripheralPins.h"
 #include "PeripheralPinConfigs.h"
 
+#include "am_hal_adc.h"
+#include "objects.h"
+
 /************RTC***************/
 const PinMap PinMap_RTC[] = {
     {NC, 0, 0},
 };
 
 /************ADC***************/
 const PinMap PinMap_ADC[] = {
+    {11, ADC0_2, AM_HAL_PIN_11_ADCSE2},
+    {12, ADC0_9, AM_HAL_PIN_12_ADCD0NSE9},
+    {13, ADC0_8, AM_HAL_PIN_13_ADCD0PSE8},
+    {16, ADC0_0, AM_HAL_PIN_16_ADCSE0},
+    {29, ADC0_1, AM_HAL_PIN_29_ADCSE1},
+    {31, ADC0_3, AM_HAL_PIN_31_ADCSE3},
+    {32, ADC0_4, AM_HAL_PIN_32_ADCSE4},
+    {33, ADC0_5, AM_HAL_PIN_33_ADCSE5},
+    {34, ADC0_6, AM_HAL_PIN_34_ADCSE6},
+    {35, ADC0_7, AM_HAL_PIN_35_ADCSE7},
+    {ADC_TEMP, ADC0_TEMP, 0},
     {NC, NC, 0}
 };