Hello tsaitgaist,
I'd like you to do a code review. Please visit
https://gerrit.osmocom.org/c/simtrace2/+/23615
to review the following change.
Change subject: minor add comments
......................................................................
minor add comments
this is just to better understand the flow
Change-Id: I045286836176da729cc8c863866d6f6aa3836592
---
M firmware/libcommon/source/mode_cardemu.c
1 file changed, 24 insertions(+), 15 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/simtrace2 refs/changes/15/23615/1
diff --git a/firmware/libcommon/source/mode_cardemu.c
b/firmware/libcommon/source/mode_cardemu.c
index 6a8d98f..7a37317 100644
--- a/firmware/libcommon/source/mode_cardemu.c
+++ b/firmware/libcommon/source/mode_cardemu.c
@@ -1,7 +1,7 @@
/* card emulation mode
*
* (C) 2015-2017 by Harald Welte <lafo...@gnumonks.org>
- * (C) 2018 by sysmocom -s.f.m.c. GmbH, Author: Kevin Redon
<kre...@sysmocom.de>
+ * (C) 2018-2019 by sysmocom -s.f.m.c. GmbH, Author: Kevin Redon
<kre...@sysmocom.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@@ -202,32 +202,33 @@
uint32_t csr;
uint8_t byte = 0;
- csr = usart->US_CSR & usart->US_IMR;
+ csr = usart->US_CSR & usart->US_IMR; // save state/flags before they
get changed
- if (csr & US_CSR_RXRDY) {
- byte = (usart->US_RHR) & 0xFF;
- if (rbuf_write(&ci->rb, byte) < 0)
- TRACE_ERROR("rbuf overrun\r\n");
+ if (csr & US_CSR_RXRDY) { // bytes has been received
+ byte = (usart->US_RHR) & 0xFF; // ready out byte
+ if (rbuf_write(&ci->rb, byte) < 0) // store byte in buffer
+ TRACE_ERROR("rbuf overrun\r\n"); // error if could not
store in buffer
}
- if (csr & US_CSR_TXRDY) {
- if (card_emu_tx_byte(ci->ch) == 0)
- USART_DisableIt(usart, US_IER_TXRDY);
+ if (csr & US_CSR_TXRDY) { // ready to transmit the next byte
+ if (card_emu_tx_byte(ci->ch) == 0) // transmit next byte, and
check if a byte is being transmitted
+ USART_DisableIt(usart, US_IER_TXRDY); // stop the TX
ready signal if not byte has been transmitted
}
- if (csr & (US_CSR_OVRE|US_CSR_FRAME|US_CSR_PARE|
- US_CSR_TIMEOUT|US_CSR_NACK|(1<<10))) {
- usart->US_CR = US_CR_RSTSTA | US_CR_RSTIT | US_CR_RSTNACK;
- TRACE_ERROR("%u e 0x%x st: 0x%lx\n", ci->num, byte, csr);
+ if (csr &
(US_CSR_OVRE|US_CSR_FRAME|US_CSR_PARE|US_CSR_TIMEOUT|US_CSR_NACK|(1<<10))) { //
error flag set
+ usart->US_CR = US_CR_RSTSTA | US_CR_RSTIT | US_CR_RSTNACK; //
reset UART state to clear flag
+ TRACE_ERROR("%u USART error on 0x%x status: 0x%lx\n", ci->num,
byte, csr); // warn user about error
}
}
+/*! ISR called for USART0 */
void mode_cardemu_usart0_irq(void)
{
/* USART0 == Instance 1 == USIM 2 */
usart_irq_rx(1);
}
+/*! ISR called for USART1 */
void mode_cardemu_usart1_irq(void)
{
/* USART1 == Instance 0 == USIM 1 */
@@ -419,15 +420,21 @@
INIT_LLIST_HEAD(&cardem_inst[0].usb_out_queue);
rbuf_reset(&cardem_inst[0].rb);
PIO_Configure(pins_usim1, PIO_LISTSIZE(pins_usim1));
+
+ /* configure USART as ISO-7816 slave (e.g. card) */
ISO7816_Init(&cardem_inst[0].usart_info, CLK_SLAVE);
NVIC_EnableIRQ(USART1_IRQn);
PIO_ConfigureIt(&pin_usim1_rst, usim1_rst_irqhandler);
PIO_EnableIt(&pin_usim1_rst);
- usim1_rst_irqhandler(&pin_usim1_rst); /* obtain current RST state */
+
+ /* obtain current RST state */
+ usim1_rst_irqhandler(&pin_usim1_rst);
#ifndef DETECT_VCC_BY_ADC
PIO_ConfigureIt(&pin_usim1_vcc, usim1_vcc_irqhandler);
PIO_EnableIt(&pin_usim1_vcc);
- usim1_vcc_irqhandler(&pin_usim1_vcc); /* obtain current VCC state */
+
+ /* obtain current VCC state */
+ usim1_vcc_irqhandler(&pin_usim1_vcc);
#else
do {} while (!adc_triggered); /* wait for first ADC reading */
#endif /* DETECT_VCC_BY_ADC */
@@ -442,6 +449,7 @@
rbuf_reset(&cardem_inst[1].rb);
PIO_Configure(pins_usim2, PIO_LISTSIZE(pins_usim2));
ISO7816_Init(&cardem_inst[1].usart_info, CLK_SLAVE);
+ // TODO enable timeout
NVIC_EnableIRQ(USART0_IRQn);
PIO_ConfigureIt(&pin_usim2_rst, usim2_rst_irqhandler);
PIO_EnableIt(&pin_usim2_rst);
@@ -458,6 +466,7 @@
SIMTRACE_CARDEM_USB_EP_USIM2_INT,
cardem_inst[1].vcc_active,
cardem_inst[1].rst_active,
cardem_inst[1].vcc_active);
sim_switch_use_physical(1, 1);
+ // TODO check rst and vcc
#endif /* CARDEMU_SECOND_UART */
}
--
To view, visit https://gerrit.osmocom.org/c/simtrace2/+/23615
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Gerrit-Project: simtrace2
Gerrit-Branch: master
Gerrit-Change-Id: I045286836176da729cc8c863866d6f6aa3836592
Gerrit-Change-Number: 23615
Gerrit-PatchSet: 1
Gerrit-Owner: laforge <lafo...@osmocom.org>
Gerrit-Reviewer: tsaitgaist <kre...@sysmocom.de>
Gerrit-MessageType: newchange
