flipperzero-firmware/core/furi-hal/api-spi.h
2021-08-08 21:03:25 +03:00

145 lines
3.5 KiB
C

#include <furi.h>
#ifdef __cplusplus
extern "C" {
#endif
/*
struct used for handling SPI info.
*/
typedef struct {
SPI_HandleTypeDef* spi;
PubSubCallback cb;
void* ctx;
} SpiHandle;
/*
For transmit/receive data use `spi_xfer` function.
* `tx_data` and `rx_data` size must be equal (and equal `len`)
* `cb` called after spi operation is completed, `(NULL, ctx)` passed to callback.
*/
bool spi_xfer(
SPI_HandleTypeDef* spi,
uint8_t* tx_data,
uint8_t* rx_data,
size_t len,
PubSubCallback cb,
void* ctx);
/*
Blocking verison:
*/
static inline bool
spi_xfer_block(SPI_HandleTypeDef* spi, uint8_t* tx_data, uint8_t* rx_data, size_t len) {
semaphoreInfo s;
osSemaphore block = createSemaphoreStatic(s);
if(!spi_xfer(spi, tx_data, rx_data, len, RELEASE_SEMAPHORE, (void*)block)) {
osReleaseSemaphore(block);
return false;
}
osWaitSemaphore(block);
return false;
}
/*
Common implementation of SPI bus: serial interface + CS pin
*/
typedef struct {
GpioPin* cs; ///< CS pin
ValueMutex* spi; ///< <SpiHandle*>
} SpiBus;
/*
For dedicated work with one device there is `SpiDevice` entity.
It contains ValueMutex around SpiBus: after you acquire device
you can acquire spi to work with it (don't forget SPI bus is shared
around many device, release it after every transaction as quick as possible).
*/
typedef struct {
ValueMutex* bus; ///< <SpiBus*>
} SpiDevice;
##SPI IRQ device
/*
Many devices (like CC1101 and NFC) present as SPI bus and IRQ line.
For work with it there is special entity `SpiIrqDevice`.
Use `subscribe_pubsub` for subscribinq to irq events.
*/
typedef struct {
ValueMutex* bus; ///< <SpiBus*>
PubSub* irq;
} SpiIrqDevice;
/*
Special implementation of SPI bus: serial interface + CS, Res, D/I lines.
*/
typedef struct {
GpioPin* cs; ///< CS pin
GpioPin* res; ///< reset pin
GpioPin* di; ///< D/I pin
ValueMutex* spi; ///< <SPI_HandleTypeDef*>
} DisplayBus;
typedef struct {
ValueMutex* bus; ///< <DisplayBus*>
} DisplayDevice;
/*
# SPI devices (F2)
* `/dev/sdcard` - SD card SPI, `SpiDevice`
* `/dev/cc1101_bus` - Sub-GHz radio (CC1101), `SpiIrqDevice`
* `/dev/nfc` - NFC (ST25R3916), `SpiIrqDevice`
* `/dev/display` - `DisplayDevice`
* `/dev/spiext` - External SPI (warning! Lock PA4, PA5, PA6, PA7)
### Application example
```C
// Be careful, this function called from IRQ context
void handle_irq(void* _arg, void* _ctx) {
}
void cc1101_example() {
SpiIrqDevice* cc1101_device = open_input("/dev/cc1101_bus");
if(cc1101_device == NULL) return; // bus not available, critical error
subscribe_pubsub(cc1101_device->irq, handle_irq, NULL);
{
// acquire device as device bus
SpiBus* spi_bus = acquire_mutex(cc1101_device->bus, 0);
if(spi_bus == NULL) {
printf("Device busy\n");
// wait for device
spi_bus = acquire_mutex_block(cc1101_device->bus);
}
// make transaction
uint8_t request[4] = {0xDE, 0xAD, 0xBE, 0xEF};
uint8_t response[4];
{
SPI_HandleTypeDef* spi = acquire_mutex_block(spi_bus->spi);
gpio_write(spi_bus->cs, false);
spi_xfer_block(spi, request, response, 4);
gpio_write(spi_bus->cs, true);
release_mutex(cc1101_device->spi, spi);
}
// release device (device bus)
release_mutex(cc1101_device->bus, spi_bus);
}
}
```
*/
#ifdef __cplusplus
}
#endif