1 /*-
32  * The mini Uart has the following features: 
33  * - 7 or 8 bit operation. 
34  * - 1 start and 1 stop bit. 
35  * - No parities. 
36  * - Break generation. 
37  * - 8 symbols deep FIFOs for receive and transmit. 
38  * - SW controlled RTS, SW readable CTS. 
39  * - Auto flow control with programmable FIFO level. 
40  * - 16550 like registers. 
41  * - Baudrate derived from system clock. 
42  * This is a mini UART and it does NOT have the following capabilities: 
43  * - Break detection 
44  * - Framing errors detection. 
45  * - Parity bit 
46  * - Receive Time-out interrupt 
47  * - DCD, DSR, DTR or RI signals. 
48  * The implemented UART is not a 16650 compatible UART However as far
50  * like a 16550 UART. All 16550 register bits which are not supported can
52  * for simple UART receive/transmit operations are available.
67 #include <dev/uart/uart.h>
68 #include <dev/uart/uart_cpu.h>
70 #include <dev/uart/uart_cpu_fdt.h>
73 #include <dev/uart/uart_bus.h>
76 /* BCM2835 Micro UART registers and masks*/
124  * FIXME: actual register size is SoC-dependent, we need to handle it
127 	bus_space_read_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg))
129 	bus_space_write_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg), value)
132  * Low-level UART interface.
159  * the micro-uart is used 
172 	 * UART is disabled and not configured  in uart_mu_param()
177 	/* As I know UART is disabled I can setup the line */  in uart_mu_param()
191 	/* See 2.2.1 BCM2835-ARM-Peripherals baudrate */  in uart_mu_param()
200 	/* re-enable UART */  in uart_mu_param()
248  * High-level UART interface.
287 	"aux-uart",
298 	{"brcm,bcm2835-aux-uart" , (uintptr_t)&uart_mu_class},
311 	bas = &sc->sc_bas;  in uart_mu_bus_attach()
315 	psc->aux_ier = (IER_RXENABLE|IER_TXENABLE|IER_REQUIRED);  in uart_mu_bus_attach()
316 	__uart_setreg(bas, AUX_MU_IER_REG, psc->aux_ier);  in uart_mu_bus_attach()
317 	sc->sc_txbusy = 0;  in uart_mu_bus_attach()
349 	uart_lock(sc->sc_hwmtx);  in uart_mu_bus_ioctl()
360 	uart_unlock(sc->sc_hwmtx);  in uart_mu_bus_ioctl()
374 	bas = &sc->sc_bas;  in uart_mu_bus_ipend()
376 	uart_lock(sc->sc_hwmtx);  in uart_mu_bus_ipend()
388 			if (sc->sc_txbusy)  in uart_mu_bus_ipend()
393 				      psc->aux_ier & ~IER_TXENABLE);  in uart_mu_bus_ipend()
397 	uart_unlock(sc->sc_hwmtx);  in uart_mu_bus_ipend()
407 	uart_lock(sc->sc_hwmtx);  in uart_mu_bus_param()
408 	uart_mu_param(&sc->sc_bas, baudrate, databits, stopbits, parity);  in uart_mu_bus_param()
409 	uart_unlock(sc->sc_hwmtx);  in uart_mu_bus_param()
419 	sc->sc_rxfifosz = 8;  in uart_mu_bus_probe()
420 	sc->sc_txfifosz = 8;  in uart_mu_bus_probe()
421 	device_set_desc(sc->sc_dev, "BCM2835 Mini-UART");  in uart_mu_bus_probe()
433 	bas = &sc->sc_bas;  in uart_mu_bus_receive()
434 	uart_lock(sc->sc_hwmtx);  in uart_mu_bus_receive()
441 			sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;  in uart_mu_bus_receive()
447 	uart_unlock(sc->sc_hwmtx);  in uart_mu_bus_receive()
467 	bas = &sc->sc_bas;  in uart_mu_bus_transmit()
468 	uart_lock(sc->sc_hwmtx);  in uart_mu_bus_transmit()
470   	for (i = 0; i < sc->sc_txdatasz; i++) {  in uart_mu_bus_transmit()
471 		__uart_setreg(bas, AUX_MU_IO_REG, sc->sc_txbuf[i] & 0xff);  in uart_mu_bus_transmit()
476 	sc->sc_txbusy = 1;  in uart_mu_bus_transmit()
477 	__uart_setreg(bas, AUX_MU_IER_REG, psc->aux_ier);  in uart_mu_bus_transmit()
479 	uart_unlock(sc->sc_hwmtx);  in uart_mu_bus_transmit()
491 	bas = &sc->sc_bas;  in uart_mu_bus_grab()
494 	uart_lock(sc->sc_hwmtx);  in uart_mu_bus_grab()
495 	__uart_setreg(bas, AUX_MU_IER_REG, psc->aux_ier &~IER_MASK_ALL);  in uart_mu_bus_grab()
496 	uart_unlock(sc->sc_hwmtx);  in uart_mu_bus_grab()
506 	bas = &sc->sc_bas;  in uart_mu_bus_ungrab()
509 	uart_lock(sc->sc_hwmtx);  in uart_mu_bus_ungrab()
511 	__uart_setreg(bas, AUX_MU_IER_REG, psc->aux_ier);  in uart_mu_bus_ungrab()
512 	uart_unlock(sc->sc_hwmtx);  in uart_mu_bus_ungrab()