/* vim: tabstop=4 shiftwidth=4 noexpandtab * * Serial communication device * */ #include #include #include #include #include #define SERIAL_PORT_A 0x3F8 #define SERIAL_PORT_B 0x2F8 #define SERIAL_PORT_C 0x3E8 #define SERIAL_PORT_D 0x2E8 #define SERIAL_IRQ_AC 4 #define SERIAL_IRQ_BD 3 #undef FORCE_DEBUG_OUTPUT_TO_SERIAL static char serial_recv(int device); static fs_node_t * _serial_port_a = NULL; static fs_node_t * _serial_port_b = NULL; static fs_node_t * _serial_port_c = NULL; static fs_node_t * _serial_port_d = NULL; static uint8_t convert(uint8_t in) { switch (in) { case 0x7F: return 0x08; case 0x0D: return '\n'; default: return in; } } static fs_node_t ** pipe_for_port(int port) { switch (port) { case SERIAL_PORT_A: return &_serial_port_a; case SERIAL_PORT_B: return &_serial_port_b; case SERIAL_PORT_C: return &_serial_port_c; case SERIAL_PORT_D: return &_serial_port_d; } return NULL; } static void serial_handler_ac(struct regs *r) { char serial; int port = 0; if (inportb(SERIAL_PORT_A+1) & 0x01) { port = SERIAL_PORT_A; } else { port = SERIAL_PORT_C; } serial = serial_recv(port); irq_ack(SERIAL_IRQ_AC); uint8_t buf[] = {convert(serial), 0}; write_fs(*pipe_for_port(port), 0, 1, buf); } static void serial_handler_bd(struct regs *r) { char serial; int port = 0; debug_print(NOTICE, "Received something on secondary port"); if (inportb(SERIAL_PORT_B+1) & 0x01) { port = SERIAL_PORT_B; } else { port = SERIAL_PORT_D; } serial = serial_recv(port); irq_ack(SERIAL_IRQ_BD); uint8_t buf[] = {convert(serial), 0}; write_fs(*pipe_for_port(port), 0, 1, buf); } static void serial_enable(int port) { outportb(port + 1, 0x00); /* Disable interrupts */ outportb(port + 3, 0x80); /* Enable divisor mode */ outportb(port + 0, 0x01); /* Div Low: 01 Set the port to 115200 bps */ outportb(port + 1, 0x00); /* Div High: 00 */ outportb(port + 3, 0x03); /* Disable divisor mode, set parity */ outportb(port + 2, 0xC7); /* Enable FIFO and clear */ outportb(port + 4, 0x0B); /* Enable interrupts */ outportb(port + 1, 0x01); /* Enable interrupts */ } static int serial_rcvd(int device) { return inportb(device + 5) & 1; } static char serial_recv(int device) { while (serial_rcvd(device) == 0) ; return inportb(device); } static int serial_transmit_empty(int device) { return inportb(device + 5) & 0x20; } static void serial_send(int device, char out) { while (serial_transmit_empty(device) == 0); outportb(device, out); } static void serial_string(char * out) { for (uint32_t i = 0; i < strlen(out); ++i) { serial_send(SERIAL_PORT_A, out[i]); } } static uint32_t read_serial(fs_node_t *node, uint32_t offset, uint32_t size, uint8_t *buffer); static uint32_t write_serial(fs_node_t *node, uint32_t offset, uint32_t size, uint8_t *buffer); static void open_serial(fs_node_t *node, unsigned int flags); static void close_serial(fs_node_t *node); static uint32_t read_serial(fs_node_t *node, uint32_t offset, uint32_t size, uint8_t *buffer) { return read_fs(*pipe_for_port((int)node->device), offset, size, buffer); } static uint32_t write_serial(fs_node_t *node, uint32_t offset, uint32_t size, uint8_t *buffer) { uint32_t sent = 0; while (sent < size) { serial_send((int)node->device, buffer[sent]); sent++; } return size; } static void open_serial(fs_node_t * node, unsigned int flags) { return; } static void close_serial(fs_node_t * node) { return; } static fs_node_t * serial_device_create(int device) { fs_node_t * fnode = malloc(sizeof(fs_node_t)); memset(fnode, 0x00, sizeof(fs_node_t)); fnode->device= (void *)device; strcpy(fnode->name, "serial"); fnode->uid = 0; fnode->gid = 0; fnode->flags = FS_CHARDEVICE; fnode->read = read_serial; fnode->write = write_serial; fnode->open = open_serial; fnode->close = close_serial; fnode->readdir = NULL; fnode->finddir = NULL; fnode->ioctl = NULL; /* TODO ioctls for raw serial devices */ fnode->atime = now(); fnode->mtime = fnode->atime; fnode->ctime = fnode->atime; serial_enable(device); if (device == SERIAL_PORT_A || device == SERIAL_PORT_C) { irq_install_handler(SERIAL_IRQ_AC, serial_handler_ac); } else { irq_install_handler(SERIAL_IRQ_BD, serial_handler_bd); } *pipe_for_port(device) = make_pipe(128); return fnode; } static int serial_mount_devices(void) { fs_node_t * ttyS0 = serial_device_create(SERIAL_PORT_A); vfs_mount("/dev/ttyS0", ttyS0); fs_node_t * ttyS1 = serial_device_create(SERIAL_PORT_B); vfs_mount("/dev/ttyS1", ttyS1); fs_node_t * ttyS2 = serial_device_create(SERIAL_PORT_C); vfs_mount("/dev/ttyS2", ttyS2); fs_node_t * ttyS3 = serial_device_create(SERIAL_PORT_D); vfs_mount("/dev/ttyS3", ttyS3); #ifdef FORCE_DEBUG_OUTPUT_TO_SERIAL kprint_to_file = ttyS0; debug_level = 1; #endif return 0; } static int serial_finalize(void) { return 0; } MODULE_DEF(serial, serial_mount_devices, serial_finalize);