| /* Card (ICC) UART driver for simple serial readers attached to tty. |
| * This allows you to use the CCID core in Linux userspace against a serial reader */ |
| |
| #include <unistd.h> |
| #include <termios.h> |
| #include <errno.h> |
| #include <sys/ioctl.h> |
| |
| #include <osmocom/core/select.h> |
| #include <osmocom/core/serial.h> |
| #include <osmocom/core/utils.h> |
| |
| #include "cuart.h" |
| #include "utils_ringbuffer.h" |
| |
| /*********************************************************************** |
| * low-level helper routines |
| ***********************************************************************/ |
| |
| static int _init_uart(int fd) |
| { |
| struct termios tio; |
| int rc; |
| |
| rc = tcgetattr(fd, &tio); |
| if (rc < 0) { |
| perror("tcgetattr()"); |
| return -EIO; |
| } |
| |
| tio.c_iflag = 0; |
| tio.c_oflag = 0; |
| tio.c_lflag = 0; |
| tio.c_cflag = CREAD | CLOCAL | CSTOPB | PARENB | CS8 | B9600; |
| |
| rc = tcsetattr(fd, TCSANOW, &tio); |
| if (rc < 0) { |
| perror("tcsetattr()"); |
| return -EIO; |
| } |
| |
| return 0; |
| } |
| |
| static void _set_dtr(int fd, bool dtr) |
| { |
| int status, rc; |
| |
| rc = ioctl(fd, TIOCMGET, &status); |
| OSMO_ASSERT(rc == 0); |
| if (dtr) /* set DTR */ |
| status |= TIOCM_DTR; |
| else |
| status &= ~TIOCM_DTR; |
| rc = ioctl(fd, TIOCMSET, &status); |
| OSMO_ASSERT(rc == 0); |
| } |
| |
| static void _set_rts(int fd, bool rts) |
| { |
| int status, rc; |
| |
| rc = ioctl(fd, TIOCMGET, &status); |
| OSMO_ASSERT(rc == 0); |
| if (rts) /* set RTS */ |
| status |= TIOCM_RTS; |
| else |
| status &= ~TIOCM_RTS; |
| rc = ioctl(fd, TIOCMSET, &status); |
| OSMO_ASSERT(rc == 0); |
| } |
| |
| static int read_timeout(int fd, uint8_t *out, size_t len, unsigned long timeout_ms) |
| { |
| struct timeval tv = { .tv_sec = timeout_ms / 1000, .tv_usec = (timeout_ms % 1000) * 1000 }; |
| fd_set rd_set; |
| int rc; |
| |
| FD_ZERO(&rd_set); |
| FD_SET(fd, &rd_set); |
| rc = select(fd+1, &rd_set, NULL, NULL, &tv); |
| if (rc == 0) |
| return -ETIMEDOUT; |
| else if (rc < 0) |
| return rc; |
| |
| return read(fd, out, len); |
| } |
| |
| static int _flush(int fd) |
| { |
| #if 0 |
| uint8_t buf[1]; |
| int rc; |
| |
| while (1) { |
| rc = read_timeout(fd, buf, sizeof(buf), 10); |
| if (rc == -ETIMEDOUT) |
| return 0; |
| else if (rc < 0) |
| return rc; |
| } |
| #else |
| return tcflush(fd, TCIFLUSH); |
| #endif |
| } |
| |
| /*********************************************************************** |
| * Interface with card_uart (cuart) core |
| ***********************************************************************/ |
| |
| /* forward-declaration */ |
| static struct card_uart_driver tty_uart_driver; |
| static int tty_uart_close(struct card_uart *cuart); |
| |
| static int tty_uart_fd_cb(struct osmo_fd *ofd, unsigned int what) |
| { |
| struct card_uart *cuart = (struct card_uart *) ofd->data; |
| uint8_t buf[256]; |
| int rc; |
| |
| if (what & OSMO_FD_READ) { |
| int i; |
| /* read any pending bytes and feed them into ring buffer */ |
| rc = read(ofd->fd, buf, sizeof(buf)); |
| OSMO_ASSERT(rc > 0); |
| for (i = 0; i < rc; i++) { |
| #ifndef CREAD_ACTUALLY_WORKS |
| /* work-around for https://bugzilla.kernel.org/show_bug.cgi?id=205033 */ |
| if (cuart->tx_busy) { |
| if (cuart->u.tty.rx_count_during_tx < cuart->u.tty.tx_buf_len) { |
| /* FIXME: compare! */ |
| cuart->u.tty.rx_count_during_tx += 1; |
| if (cuart->u.tty.rx_count_during_tx == cuart->u.tty.tx_buf_len) { |
| cuart->tx_busy = false; |
| card_uart_notification(cuart, CUART_E_TX_COMPLETE, |
| (void *)cuart->u.tty.tx_buf); |
| } |
| continue; |
| } |
| } |
| #endif |
| if (!cuart->rx_enabled) |
| continue; |
| |
| card_uart_wtime_restart(cuart); |
| |
| if (cuart->rx_threshold == 1) { |
| /* bypass ringbuffer and report byte directly */ |
| card_uart_notification(cuart, CUART_E_RX_SINGLE, &buf[i]); |
| } else { |
| /* go via ringbuffer and notify only after threshold */ |
| ringbuffer_put(&cuart->u.tty.rx_ringbuf, buf[i]); |
| if (ringbuffer_num(&cuart->u.tty.rx_ringbuf) >= cuart->rx_threshold) |
| card_uart_notification(cuart, CUART_E_RX_COMPLETE, NULL); |
| } |
| } |
| } |
| if (what & OSMO_FD_WRITE) { |
| unsigned int to_tx; |
| OSMO_ASSERT(cuart->u.tty.tx_buf_len > cuart->u.tty.tx_index); |
| /* push as many pending transmit bytes as possible */ |
| to_tx = cuart->u.tty.tx_buf_len - cuart->u.tty.tx_index; |
| rc = write(ofd->fd, cuart->u.tty.tx_buf + cuart->u.tty.tx_index, to_tx); |
| OSMO_ASSERT(rc > 0); |
| cuart->u.tty.tx_index += rc; |
| |
| /* if no more bytes to transmit, disable OSMO_FD_WRITE */ |
| if (cuart->u.tty.tx_index >= cuart->u.tty.tx_buf_len) { |
| ofd->when &= ~BSC_FD_WRITE; |
| #ifndef CREAD_ACTUALLY_WORKS |
| /* don't immediately notify user; first wait for characters to be received */ |
| #else |
| /* ensure everything is written (tx queue/fifo drained) */ |
| tcdrain(cuart->u.tty.ofd.fd); |
| cuart->tx_busy = false; |
| /* notify */ |
| card_uart_notification(cuart, CUART_E_TX_COMPLETE, (void *)cuart->u.tty.tx_buf); |
| #endif |
| } |
| } |
| return 0; |
| } |
| |
| static int tty_uart_open(struct card_uart *cuart, const char *device_name) |
| { |
| int rc; |
| |
| rc = ringbuffer_init(&cuart->u.tty.rx_ringbuf, cuart->u.tty.rx_buf, sizeof(cuart->u.tty.rx_buf)); |
| if (rc < 0) |
| return rc; |
| |
| cuart->u.tty.ofd.fd = -1; |
| rc = osmo_serial_init(device_name, B9600); |
| if (rc < 0) |
| return rc; |
| |
| osmo_fd_setup(&cuart->u.tty.ofd, rc, BSC_FD_READ, tty_uart_fd_cb, cuart, 0); |
| cuart->u.tty.baudrate = B9600; |
| |
| rc = _init_uart(cuart->u.tty.ofd.fd); |
| if (rc < 0) { |
| tty_uart_close(cuart); |
| return rc; |
| } |
| |
| _flush(cuart->u.tty.ofd.fd); |
| |
| osmo_fd_register(&cuart->u.tty.ofd); |
| |
| return 0; |
| } |
| |
| static int tty_uart_close(struct card_uart *cuart) |
| { |
| OSMO_ASSERT(cuart->driver == &tty_uart_driver); |
| if (cuart->u.tty.ofd.fd != -1) { |
| osmo_fd_unregister(&cuart->u.tty.ofd); |
| close(cuart->u.tty.ofd.fd); |
| cuart->u.tty.ofd.fd = -1; |
| } |
| return 0; |
| } |
| |
| static int tty_uart_async_tx(struct card_uart *cuart, const uint8_t *data, size_t len) |
| { |
| OSMO_ASSERT(cuart->driver == &tty_uart_driver); |
| |
| cuart->u.tty.tx_buf = data; |
| cuart->u.tty.tx_buf_len = len; |
| cuart->u.tty.tx_index = 0; |
| cuart->u.tty.rx_count_during_tx = 0; |
| cuart->tx_busy = true; |
| cuart->u.tty.ofd.when |= OSMO_FD_WRITE; |
| |
| return 0; |
| } |
| |
| static int tty_uart_async_rx(struct card_uart *cuart, uint8_t *data, size_t len) |
| { |
| int rc, i; |
| OSMO_ASSERT(cuart->driver == &tty_uart_driver); |
| |
| /* FIXME: actually do this asynchronously */ |
| for (i = 0; i < len; i++) { |
| rc = ringbuffer_get(&cuart->u.tty.rx_ringbuf, &data[i]); |
| if (rc < 0) |
| return i; |
| } |
| |
| return i; |
| } |
| |
| static int tty_uart_ctrl(struct card_uart *cuart, enum card_uart_ctl ctl, int arg) |
| { |
| struct termios tio; |
| int rc; |
| |
| switch (ctl) { |
| case CUART_CTL_RX: |
| rc = tcgetattr(cuart->u.tty.ofd.fd, &tio); |
| if (rc < 0) { |
| perror("tcgetattr()"); |
| return -EIO; |
| } |
| /* We do our best here, but lots of [USB] serial drivers seem to ignore |
| * CREAD, see https://bugzilla.kernel.org/show_bug.cgi?id=205033 */ |
| if (arg) { |
| tio.c_cflag |= CREAD; |
| card_uart_wtime_restart(cuart); |
| } else |
| tio.c_cflag &= ~CREAD; |
| rc = tcsetattr(cuart->u.tty.ofd.fd, TCSANOW, &tio); |
| if (rc < 0) { |
| perror("tcsetattr()"); |
| return -EIO; |
| } |
| break; |
| case CUART_CTL_RST: |
| _set_rts(cuart->u.tty.ofd.fd, arg ? true : false); |
| if (arg) |
| _flush(cuart->u.tty.ofd.fd); |
| break; |
| case CUART_CTL_WTIME: |
| /* no driver-specific handling of this */ |
| break; |
| case CUART_CTL_POWER: |
| case CUART_CTL_CLOCK: |
| default: |
| return -EINVAL; |
| } |
| return 0; |
| } |
| |
| static const struct card_uart_ops tty_uart_ops = { |
| .open = tty_uart_open, |
| .close = tty_uart_close, |
| .async_tx = tty_uart_async_tx, |
| .async_rx = tty_uart_async_rx, |
| .ctrl = tty_uart_ctrl, |
| }; |
| |
| static struct card_uart_driver tty_uart_driver = { |
| .name = "tty", |
| .ops = &tty_uart_ops, |
| }; |
| |
| static __attribute__((constructor)) void on_dso_load_cuart_tty(void) |
| { |
| card_uart_driver_register(&tty_uart_driver); |
| } |