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Change NRF52 series UART to only use one SWI channel
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This fixes conflicts with the SoftDevice.
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Marcus Chang committed Jul 9, 2018
1 parent 4f913b9 commit affb0ae
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Showing 3 changed files with 64 additions and 60 deletions.
7 changes: 4 additions & 3 deletions targets/TARGET_NORDIC/TARGET_NRF5x/README.md
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Expand Up @@ -143,9 +143,9 @@ The table must be placed in a C compilation file.
Because each DMA buffer must be at least 5 bytes deep, each buffer is automatically flushed after a certain idle period to ensure low latency and correctness. This idle timeout is implemented using 2 of the 4 channels on RTC instance 2. This leaves RTC0 for the SoftDevice and RTC1 for Mbed tickers.


#### SWI2, SWI3, SWI4, and SWI5
#### SWI0

To minimize the time spend in the highest priority interrupt handler all callbacks to the user provided IRQ handlers are deferred through Software Interrupts running at lowest priority. SWI 2-5 are reserved by the serial implementation.
To minimize the time spend in the highest priority interrupt handler all callbacks to the user provided IRQ handlers are deferred through Software Interrupts running at lowest priority. SWI0 is reserved by the serial implementation.


#### Asserts
Expand All @@ -156,13 +156,14 @@ The SDK file `mbed-os/targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_SDK_14_2/librari
The assert handler is defined in mbed-os/features/FEATURE_BLE/targets/TARGET_NORDIC/TARGET_NRF5x/source/btle/btle.cpp : assert_nrf_callback() which forwards assert failures to thye mbed error() handler.



#### Limitations

* The UARTE hardware only supports 8-bit, None/Even parity, and 1 stop bit.
* The asynchronous read and write implementation currently only support 255 byte transfers.
* The EasyDMA hardware can only read from RAM, which means all Tx buffers must reside in RAM. If a Tx buffer residing in flash is passed to the asynchronous write function, the function will try to copy the Tx buffer to a temporary internal buffer and transmit the data from there.
* It is not possible to do an asynchronous write from flash and receive non-asynchronously at the same time since the non-asynchronous receive buffer is being used as the temporary transmission buffer.
* The driver will flush the DMA buffer after a configurable timeout. During this process the UART will be halted and therefor unable to receive data. Hardware flow control should be enabled to avoid missing any data during this window.


## SoftDevice

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12 changes: 3 additions & 9 deletions targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/mbed_lib.json
View file
Expand Up @@ -18,11 +18,13 @@
"value": 8
}
},
"macros": [
"SWI_DISABLE0"
],
"target_overrides": {
"DELTA_DFBM_NQ620": {
"target.macros_add": [
"CONFIG_GPIO_AS_PINRESET",
"SWI_DISABLE0",
"NRF52_PAN_12",
"NRF52_PAN_15",
"NRF52_PAN_20",
Expand All @@ -45,7 +47,6 @@
"MTB_LAIRD_BL652": {
"target.macros_add": [
"CONFIG_GPIO_AS_PINRESET",
"SWI_DISABLE0",
"NRF52_PAN_12",
"NRF52_PAN_15",
"NRF52_PAN_20",
Expand All @@ -67,7 +68,6 @@
"MTB_UBLOX_NINA_B1": {
"target.macros_add": [
"CONFIG_GPIO_AS_PINRESET",
"SWI_DISABLE0",
"NRF52_PAN_12",
"NRF52_PAN_15",
"NRF52_PAN_20",
Expand All @@ -87,7 +87,6 @@
"NRF52_DK": {
"target.macros_add": [
"CONFIG_GPIO_AS_PINRESET",
"SWI_DISABLE0",
"NRF52_PAN_12",
"NRF52_PAN_15",
"NRF52_PAN_20",
Expand All @@ -108,7 +107,6 @@
"RBLAB_BLENANO2": {
"target.macros_add": [
"CONFIG_GPIO_AS_PINRESET",
"SWI_DISABLE0",
"NRF52_PAN_12",
"NRF52_PAN_15",
"NRF52_PAN_20",
Expand All @@ -128,7 +126,6 @@
"UBLOX_EVA_NINA": {
"target.macros_add": [
"CONFIG_GPIO_AS_PINRESET",
"SWI_DISABLE0",
"NRF52_PAN_12",
"NRF52_PAN_15",
"NRF52_PAN_20",
Expand All @@ -148,7 +145,6 @@
"UBLOX_EVK_NINA_B1": {
"target.macros_add": [
"CONFIG_GPIO_AS_PINRESET",
"SWI_DISABLE0",
"NRF52_PAN_12",
"NRF52_PAN_15",
"NRF52_PAN_20",
Expand All @@ -169,7 +165,6 @@
"VBLUNO52": {
"target.macros_add": [
"CONFIG_GPIO_AS_PINRESET",
"SWI_DISABLE0",
"NRF52_PAN_12",
"NRF52_PAN_15",
"NRF52_PAN_20",
Expand All @@ -190,7 +185,6 @@
"NRF52840_DK": {
"target.macros_add": [
"CONFIG_GPIO_AS_PINRESET",
"SWI_DISABLE0",
"NRF52_ERRATA_20"
],
"target.console-uart-flow-control": "RTSCTS"
Expand Down
105 changes: 57 additions & 48 deletions targets/TARGET_NORDIC/TARGET_NRF5x/TARGET_NRF52/serial_api.c
View file
Expand Up @@ -122,14 +122,6 @@
*/
#define RTC_FREQUENCY 32768

/**
* SWI IRQ numbers
*/
#define UARTE0_SWI_TX_IRQ SWI2_EGU2_IRQn
#define UARTE0_SWI_RX_IRQ SWI3_EGU3_IRQn
#define UARTE1_SWI_TX_IRQ SWI4_EGU4_IRQn
#define UARTE1_SWI_RX_IRQ SWI5_EGU5_IRQn

/***
* _______ _ __
* |__ __| | | / _|
Expand Down Expand Up @@ -238,6 +230,14 @@ NRF_ATFIFO_DEF(nordic_nrf5_uart_fifo_0, uint8_t, UART0_FIFO_BUFFER_SIZE);
NRF_ATFIFO_DEF(nordic_nrf5_uart_fifo_1, uint8_t, UART1_FIFO_BUFFER_SIZE);
#endif

/**
* SWI IRQ mask.
*/
static uint8_t nordic_nrf5_uart_swi_mask_tx_0 = 0;
static uint8_t nordic_nrf5_uart_swi_mask_rx_0 = 0;
static uint8_t nordic_nrf5_uart_swi_mask_tx_1 = 0;
static uint8_t nordic_nrf5_uart_swi_mask_rx_1 = 0;

/**
* Global variables expected by mbed_retarget.cpp for STDOUT.
*/
Expand Down Expand Up @@ -411,16 +411,6 @@ static void nordic_nrf5_uart_callback_handler(uint32_t instance)
}
}

static void nordic_nrf5_uart_swi_rx_0(void)
{
nordic_nrf5_uart_callback_handler(0);
}

static void nordic_nrf5_uart_swi_rx_1(void)
{
nordic_nrf5_uart_callback_handler(1);
}

/**
* @brief SWI interrupt handler for when the Tx buffer has been transmitted.
*
Expand Down Expand Up @@ -477,33 +467,55 @@ static void nordic_nrf5_uart_event_handler_endtx_asynch(int instance)
}
#endif

static void nordic_nrf5_uart_swi_tx_0(void)
static void nordic_nrf5_uart_swi0(void)
{
if (nordic_nrf5_uart_swi_mask_tx_0) {

nordic_nrf5_uart_swi_mask_tx_0 = 0;

#if DEVICE_SERIAL_ASYNCH
if (nordic_nrf5_uart_state[0].tx_asynch) {
if (nordic_nrf5_uart_state[0].tx_asynch) {

nordic_nrf5_uart_event_handler_endtx_asynch(0);
} else
nordic_nrf5_uart_event_handler_endtx_asynch(0);
} else
#endif
{
nordic_nrf5_uart_event_handler_endtx(0);
{
nordic_nrf5_uart_event_handler_endtx(0);
}
}
}

if (nordic_nrf5_uart_swi_mask_rx_0) {

nordic_nrf5_uart_swi_mask_rx_0 = 0;

nordic_nrf5_uart_callback_handler(0);
}


#if UART1_ENABLED
static void nordic_nrf5_uart_swi_tx_1(void)
{
if (nordic_nrf5_uart_swi_mask_tx_1) {

nordic_nrf5_uart_swi_mask_tx_1 = 0;

#if DEVICE_SERIAL_ASYNCH
if (nordic_nrf5_uart_state[1].tx_asynch) {
if (nordic_nrf5_uart_state[1].tx_asynch) {

nordic_nrf5_uart_event_handler_endtx_asynch(1);
} else
nordic_nrf5_uart_event_handler_endtx_asynch(1);
} else
#endif
{
nordic_nrf5_uart_event_handler_endtx(1);
{
nordic_nrf5_uart_event_handler_endtx(1);
}
}

if (nordic_nrf5_uart_swi_mask_rx_1) {

nordic_nrf5_uart_swi_mask_rx_1 = 0;

nordic_nrf5_uart_callback_handler(1);
}
}
#endif
}

/**
* @brief Trigger Tx SWI.
Expand All @@ -514,12 +526,14 @@ static void nordic_swi_tx_trigger(int instance)
{
if (instance == 0) {

NVIC_SetPendingIRQ(UARTE0_SWI_TX_IRQ);
nordic_nrf5_uart_swi_mask_tx_0 = 1;
NVIC_SetPendingIRQ(SWI0_EGU0_IRQn);
}
#if UART1_ENABLED
else if (instance == 1) {

NVIC_SetPendingIRQ(UARTE1_SWI_TX_IRQ);
nordic_nrf5_uart_swi_mask_tx_1 = 1;
NVIC_SetPendingIRQ(SWI0_EGU0_IRQn);
}
#endif
}
Expand All @@ -533,12 +547,16 @@ static void nordic_swi_rx_trigger(int instance)
{
if (instance == 0) {

NVIC_SetPendingIRQ(UARTE0_SWI_RX_IRQ);
nordic_nrf5_uart_swi_mask_rx_0 = 1;
NVIC_SetPendingIRQ(SWI0_EGU0_IRQn);
}
#if UART1_ENABLED
else if (instance == 1) {

NVIC_SetPendingIRQ(UARTE1_SWI_RX_IRQ);
nordic_nrf5_uart_swi_mask_rx_1 = 1;
NVIC_SetPendingIRQ(SWI0_EGU0_IRQn);
}
#endif
}

/***
Expand Down Expand Up @@ -990,17 +1008,8 @@ void serial_init(serial_t *obj, PinName tx, PinName rx)
nrf_rtc_task_trigger(NRF_RTC2, NRF_RTC_TASK_START);

/* Enable interrupts for SWI. */
NVIC_SetVector(UARTE0_SWI_TX_IRQ, (uint32_t) nordic_nrf5_uart_swi_tx_0);
NVIC_SetVector(UARTE0_SWI_RX_IRQ, (uint32_t) nordic_nrf5_uart_swi_rx_0);
nrf_drv_common_irq_enable(UARTE0_SWI_TX_IRQ, APP_IRQ_PRIORITY_LOWEST);
nrf_drv_common_irq_enable(UARTE0_SWI_RX_IRQ, APP_IRQ_PRIORITY_LOWEST);

#if UART1_ENABLED
NVIC_SetVector(UARTE1_SWI_TX_IRQ, (uint32_t) nordic_nrf5_uart_swi_tx_1);
NVIC_SetVector(UARTE1_SWI_RX_IRQ, (uint32_t) nordic_nrf5_uart_swi_rx_1);
nrf_drv_common_irq_enable(UARTE1_SWI_TX_IRQ, APP_IRQ_PRIORITY_LOWEST);
nrf_drv_common_irq_enable(UARTE1_SWI_RX_IRQ, APP_IRQ_PRIORITY_LOWEST);
#endif
NVIC_SetVector(SWI0_EGU0_IRQn, (uint32_t) nordic_nrf5_uart_swi0);
nrf_drv_common_irq_enable(SWI0_EGU0_IRQn, APP_IRQ_PRIORITY_LOWEST);

/* Initialize FIFO buffer for UARTE0. */
NRF_ATFIFO_INIT(nordic_nrf5_uart_fifo_0);
Expand Down

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