spi_master for AVR (#8299)

* Change _delay_ms/us() to wait_ms/us()

* Switch to platform-agnostic GPIO macros

* Add AVR spi_master and migrate Adafruit BLE code

* Set verbose back to false

* Add clock divisor, bit order and SPI mode configuration for init

* Add start and stop functions

* Move configuration of mode, endianness and speed to `spi_start()`

* Some breaks here would be good

* Default Adafruit BLE clock divisor to 4 (2MHz on the Feather 32U4)

* Remove mode and divisor enums

* Add some docs

* No hr at EOF

* Add links in sidebar
This commit is contained in:
Ryan
2020-04-08 11:04:31 +10:00
committed by GitHub
parent e409fb47f2
commit 400ca2d035
14 changed files with 397 additions and 125 deletions

View File

@ -1,15 +1,15 @@
#include "adafruit_ble.h"
#include <stdio.h>
#include <stdlib.h>
#include <alloca.h>
#include <util/delay.h>
#include <util/atomic.h>
#include "debug.h"
#include "pincontrol.h"
#include "timer.h"
#include "action_util.h"
#include "ringbuffer.hpp"
#include <string.h>
#include "spi_master.h"
#include "wait.h"
#include "analog.h"
// These are the pin assignments for the 32u4 boards.
@ -27,6 +27,12 @@
# define AdafruitBleIRQPin E6
#endif
#ifndef AdafruitBleSpiClockSpeed
# define AdafruitBleSpiClockSpeed 4000000UL // SCK frequency
#endif
#define SCK_DIVISOR (F_CPU / AdafruitBleSpiClockSpeed)
#define SAMPLE_BATTERY
#define ConnectionUpdateInterval 1000 /* milliseconds */
@ -130,10 +136,6 @@ enum ble_system_event_bits {
BleSystemMidiRx = 10,
};
// The SDEP.md file says 2MHz but the web page and the sample driver
// both use 4MHz
#define SpiBusSpeed 4000000
#define SdepTimeout 150 /* milliseconds */
#define SdepShortTimeout 10 /* milliseconds */
#define SdepBackOff 25 /* microseconds */
@ -142,116 +144,32 @@ enum ble_system_event_bits {
static bool at_command(const char *cmd, char *resp, uint16_t resplen, bool verbose, uint16_t timeout = SdepTimeout);
static bool at_command_P(const char *cmd, char *resp, uint16_t resplen, bool verbose = false);
struct SPI_Settings {
uint8_t spcr, spsr;
};
static struct SPI_Settings spi;
// Initialize 4Mhz MSBFIRST MODE0
void SPI_init(struct SPI_Settings *spi) {
spi->spcr = _BV(SPE) | _BV(MSTR);
#if F_CPU == 8000000
// For MCUs running at 8MHz (such as Feather 32U4, or 3.3V Pro Micros) we set the SPI doublespeed bit
spi->spsr = _BV(SPI2X);
#endif
ATOMIC_BLOCK(ATOMIC_RESTORESTATE) {
// Ensure that SS is OUTPUT High
digitalWrite(B0, PinLevelHigh);
pinMode(B0, PinDirectionOutput);
SPCR |= _BV(MSTR);
SPCR |= _BV(SPE);
pinMode(B1 /* SCK */, PinDirectionOutput);
pinMode(B2 /* MOSI */, PinDirectionOutput);
}
}
static inline void SPI_begin(struct SPI_Settings *spi) {
SPCR = spi->spcr;
SPSR = spi->spsr;
}
static inline uint8_t SPI_TransferByte(uint8_t data) {
SPDR = data;
asm volatile("nop");
while (!(SPSR & _BV(SPIF))) {
; // wait
}
return SPDR;
}
static inline void spi_send_bytes(const uint8_t *buf, uint8_t len) {
if (len == 0) return;
const uint8_t *end = buf + len;
while (buf < end) {
SPDR = *buf;
while (!(SPSR & _BV(SPIF))) {
; // wait
}
++buf;
}
}
static inline uint16_t spi_read_byte(void) { return SPI_TransferByte(0x00 /* dummy */); }
static inline void spi_recv_bytes(uint8_t *buf, uint8_t len) {
const uint8_t *end = buf + len;
if (len == 0) return;
while (buf < end) {
SPDR = 0; // write a dummy to initiate read
while (!(SPSR & _BV(SPIF))) {
; // wait
}
*buf = SPDR;
++buf;
}
}
#if 0
static void dump_pkt(const struct sdep_msg *msg) {
print("pkt: type=");
print_hex8(msg->type);
print(" cmd=");
print_hex8(msg->cmd_high);
print_hex8(msg->cmd_low);
print(" len=");
print_hex8(msg->len);
print(" more=");
print_hex8(msg->more);
print("\n");
}
#endif
// Send a single SDEP packet
static bool sdep_send_pkt(const struct sdep_msg *msg, uint16_t timeout) {
SPI_begin(&spi);
digitalWrite(AdafruitBleCSPin, PinLevelLow);
spi_start(AdafruitBleCSPin, false, 0, SCK_DIVISOR);
uint16_t timerStart = timer_read();
bool success = false;
bool ready = false;
do {
ready = SPI_TransferByte(msg->type) != SdepSlaveNotReady;
ready = spi_write(msg->type, 100) != SdepSlaveNotReady;
if (ready) {
break;
}
// Release it and let it initialize
digitalWrite(AdafruitBleCSPin, PinLevelHigh);
_delay_us(SdepBackOff);
digitalWrite(AdafruitBleCSPin, PinLevelLow);
spi_stop();
wait_us(SdepBackOff);
spi_start(AdafruitBleCSPin, false, 0, SCK_DIVISOR);
} while (timer_elapsed(timerStart) < timeout);
if (ready) {
// Slave is ready; send the rest of the packet
spi_send_bytes(&msg->cmd_low, sizeof(*msg) - (1 + sizeof(msg->payload)) + msg->len);
spi_transmit(&msg->cmd_low, sizeof(*msg) - (1 + sizeof(msg->payload)) + msg->len, 100);
success = true;
}
digitalWrite(AdafruitBleCSPin, PinLevelHigh);
spi_stop();
return success;
}
@ -275,41 +193,39 @@ static bool sdep_recv_pkt(struct sdep_msg *msg, uint16_t timeout) {
bool ready = false;
do {
ready = digitalRead(AdafruitBleIRQPin);
ready = readPin(AdafruitBleIRQPin);
if (ready) {
break;
}
_delay_us(1);
wait_us(1);
} while (timer_elapsed(timerStart) < timeout);
if (ready) {
SPI_begin(&spi);
digitalWrite(AdafruitBleCSPin, PinLevelLow);
spi_start(AdafruitBleCSPin, false, 0, SCK_DIVISOR);
do {
// Read the command type, waiting for the data to be ready
msg->type = spi_read_byte();
msg->type = spi_read(100);
if (msg->type == SdepSlaveNotReady || msg->type == SdepSlaveOverflow) {
// Release it and let it initialize
digitalWrite(AdafruitBleCSPin, PinLevelHigh);
_delay_us(SdepBackOff);
digitalWrite(AdafruitBleCSPin, PinLevelLow);
spi_stop();
wait_us(SdepBackOff);
spi_start(AdafruitBleCSPin, false, 0, SCK_DIVISOR);
continue;
}
// Read the rest of the header
spi_recv_bytes(&msg->cmd_low, sizeof(*msg) - (1 + sizeof(msg->payload)));
spi_receive(&msg->cmd_low, sizeof(*msg) - (1 + sizeof(msg->payload)), 100);
// and get the payload if there is any
if (msg->len <= SdepMaxPayload) {
spi_recv_bytes(msg->payload, msg->len);
spi_receive(msg->payload, msg->len, 100);
}
success = true;
break;
} while (timer_elapsed(timerStart) < timeout);
digitalWrite(AdafruitBleCSPin, PinLevelHigh);
spi_stop();
}
return success;
}
@ -320,7 +236,7 @@ static void resp_buf_read_one(bool greedy) {
return;
}
if (digitalRead(AdafruitBleIRQPin)) {
if (readPin(AdafruitBleIRQPin)) {
struct sdep_msg msg;
again:
@ -331,7 +247,7 @@ static void resp_buf_read_one(bool greedy) {
dprintf("recv latency %dms\n", TIMER_DIFF_16(timer_read(), last_send));
}
if (greedy && resp_buf.peek(last_send) && digitalRead(AdafruitBleIRQPin)) {
if (greedy && resp_buf.peek(last_send) && readPin(AdafruitBleIRQPin)) {
goto again;
}
}
@ -361,7 +277,7 @@ static void send_buf_send_one(uint16_t timeout = SdepTimeout) {
dprintf("send_buf_send_one: have %d remaining\n", (int)send_buf.size());
} else {
dprint("failed to send, will retry\n");
_delay_ms(SdepTimeout);
wait_ms(SdepTimeout);
resp_buf_read_one(true);
}
}
@ -382,20 +298,18 @@ static bool ble_init(void) {
state.configured = false;
state.is_connected = false;
pinMode(AdafruitBleIRQPin, PinDirectionInput);
pinMode(AdafruitBleCSPin, PinDirectionOutput);
digitalWrite(AdafruitBleCSPin, PinLevelHigh);
setPinInput(AdafruitBleIRQPin);
SPI_init(&spi);
spi_init();
// Perform a hardware reset
pinMode(AdafruitBleResetPin, PinDirectionOutput);
digitalWrite(AdafruitBleResetPin, PinLevelHigh);
digitalWrite(AdafruitBleResetPin, PinLevelLow);
_delay_ms(10);
digitalWrite(AdafruitBleResetPin, PinLevelHigh);
setPinOutput(AdafruitBleResetPin);
writePinHigh(AdafruitBleResetPin);
writePinLow(AdafruitBleResetPin);
wait_ms(10);
writePinHigh(AdafruitBleResetPin);
_delay_ms(1000); // Give it a second to initialize
wait_ms(1000); // Give it a second to initialize
state.initialized = true;
return state.initialized;
@ -596,7 +510,7 @@ void adafruit_ble_task(void) {
resp_buf_read_one(true);
send_buf_send_one(SdepShortTimeout);
if (resp_buf.empty() && (state.event_flags & UsingEvents) && digitalRead(AdafruitBleIRQPin)) {
if (resp_buf.empty() && (state.event_flags & UsingEvents) && readPin(AdafruitBleIRQPin)) {
// Must be an event update
if (at_command_P(PSTR("AT+EVENTSTATUS"), resbuf, sizeof(resbuf))) {
uint32_t mask = strtoul(resbuf, NULL, 16);