HelenOS sources

LSR_DATA_READY     81 kernel/genarch/src/drivers/ns16550/ns16550.c 	if (ns16550_reg_read(instance, NS16550_REG_LSR) & LSR_DATA_READY)
LSR_DATA_READY     91 kernel/genarch/src/drivers/ns16550/ns16550.c 	while (ns16550_reg_read(instance, NS16550_REG_LSR) & LSR_DATA_READY) {
LSR_DATA_READY    101 kernel/genarch/src/drivers/ns16550/ns16550.c 	    ns16550_reg_read(instance, NS16550_REG_LSR) & LSR_DATA_READY,
HelenOS homepage, sources at GitHub