mode_cardemu: Move GPIO detection to IRQ, use ring buffer for UART RX
We don't want to call into the bulk of card_emu.c from interrupt
context, so let's introduce a ring buffer as a softwre-FIFO between
the USART receiving a byte and the processing of that byte in
card_emu.c, which is then performed from the main loop outside
interrupt context.
diff --git a/firmware/src_simtrace/mode_cardemu.c b/firmware/src_simtrace/mode_cardemu.c
index 2bcecc6..21f3735 100644
--- a/firmware/src_simtrace/mode_cardemu.c
+++ b/firmware/src_simtrace/mode_cardemu.c
@@ -18,6 +18,7 @@
#endif
static struct card_handle *ch1, *ch2;
+static struct ringbuf ch1_rb;
static struct Usart_info usart_info[] = {
{
@@ -87,23 +88,31 @@
/* FIXME: integrate this with actual irq handler */
-void usart_irq_rx(uint8_t uart, uint32_t csr, uint8_t byte)
+void usart_irq_rx(uint8_t uart)
{
+ Usart *usart = get_usart_by_chan(uart);
struct card_handle *ch = ch1;
+ uint32_t csr;
+ uint8_t byte = 0;
+
#ifdef CARDEMU_SECOND_UART
- if (uart == 0)
+ if (uart == 1)
ch = ch2;
#endif
+ csr = usart->US_CSR;
if (csr & US_CSR_TXRDY)
card_emu_tx_byte(ch);
- if (csr & US_CSR_RXRDY)
- card_emu_process_rx_byte(ch, byte);
+ if (csr & US_CSR_RXRDY) {
+ byte = (usart->US_RHR) & 0xFF;
+ rbuf_write(&ch1_rb, byte);
+ }
if (csr & (US_CSR_OVRE|US_CSR_FRAME|US_CSR_PARE|
US_CSR_TIMEOUT|US_CSR_NACK|(1<<10))) {
- TRACE_DEBUG("e 0x%x st: 0x%x\n", byte, csr);
+ usart->US_CR = US_CR_RSTSTA | US_CR_RSTIT | US_CR_RSTNACK;
+ TRACE_ERROR("e 0x%x st: 0x%x\n", byte, csr);
}
}
@@ -123,6 +132,20 @@
* Core USB / mainloop integration
***********************************************************************/
+static void usim1_rst_irqhandler(const Pin *pPin)
+{
+ int active = PIO_Get(&pin_usim1_rst) ? 0 : 1;
+ card_emu_io_statechg(ch1, CARD_IO_RST, active);
+}
+
+static void usim1_vcc_irqhandler(const Pin *pPin)
+{
+ int active = PIO_Get(&pin_usim1_vcc) ? 1 : 0;
+ card_emu_io_statechg(ch1, CARD_IO_VCC, active);
+ /* FIXME do this for real */
+ card_emu_io_statechg(ch1, CARD_IO_CLK, active);
+}
+
/* executed once at system boot for each config */
void mode_cardemu_configure(void)
{
@@ -134,12 +157,20 @@
{
TRACE_ENTRY();
+ rbuf_reset(&ch1_rb);
+
PIO_Configure(pins_cardsim, PIO_LISTSIZE(pins_cardsim));
PIO_Configure(pins_usim1, PIO_LISTSIZE(pins_usim1));
ISO7816_Init(&usart_info[0], CLK_SLAVE);
//USART_EnableIt(USART1, US_IER_RXRDY);
NVIC_EnableIRQ(USART1_IRQn);
+
+ PIO_ConfigureIt(&pin_usim1_rst, usim1_rst_irqhandler);
+ PIO_EnableIt(&pin_usim1_rst);
+ PIO_ConfigureIt(&pin_usim1_vcc, usim1_vcc_irqhandler);
+ PIO_EnableIt(&pin_usim1_vcc);
+
ch1 = card_emu_init(0, 2, 0);
#ifdef CARDEMU_SECOND_UART
@@ -156,6 +187,9 @@
{
TRACE_ENTRY();
+ PIO_DisableIt(&pin_usim1_rst);
+ PIO_DisableIt(&pin_usim1_vcc);
+
NVIC_DisableIRQ(USART1_IRQn);
USART_SetTransmitterEnabled(USART1, 0);
USART_SetReceiverEnabled(USART1, 0);
@@ -170,16 +204,20 @@
/* main loop function, called repeatedly */
void mode_cardemu_run(void)
{
- int rst_active, vcc_active;
/* usb_to_host() is handled by main() */
if (ch1) {
- rst_active = PIO_Get(&pin_usim1_rst) ? 0 : 1;
- vcc_active = PIO_Get(&pin_usim1_vcc) ? 1 : 0;
- card_emu_io_statechg(ch1, CARD_IO_RST, rst_active);
- card_emu_io_statechg(ch1, CARD_IO_VCC, vcc_active);
- /* FIXME: clock ? */
+ while (1) {
+ __disable_irq();
+ if (rbuf_is_empty(&ch1_rb)) {
+ __enable_irq();
+ break;
+ }
+ uint8_t byte = rbuf_read(&ch1_rb);
+ __enable_irq();
+ card_emu_process_rx_byte(ch1, byte);
+ }
}
usb_from_host(PHONE_DATAOUT);