2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2012 Semihalf.
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
17 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
20 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
21 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
22 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
23 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
24 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
25 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 #include "opt_platform.h"
32 #include <sys/cdefs.h>
33 __FBSDID("$FreeBSD$");
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/kernel.h>
39 #include <machine/bus.h>
41 #include <dev/uart/uart.h>
42 #include <dev/uart/uart_cpu.h>
44 #include <dev/uart/uart_cpu_fdt.h>
45 #include <dev/ofw/ofw_bus.h>
47 #include <dev/uart/uart_bus.h>
51 #include <dev/uart/uart_cpu_acpi.h>
52 #include <contrib/dev/acpica/include/acpi.h>
53 #include <contrib/dev/acpica/include/accommon.h>
54 #include <contrib/dev/acpica/include/actables.h>
59 /* PL011 UART registers and masks*/
60 #define UART_DR 0x00 /* Data register */
61 #define DR_FE (1 << 8) /* Framing error */
62 #define DR_PE (1 << 9) /* Parity error */
63 #define DR_BE (1 << 10) /* Break error */
64 #define DR_OE (1 << 11) /* Overrun error */
66 #define UART_FR 0x06 /* Flag register */
67 #define FR_RXFE (1 << 4) /* Receive FIFO/reg empty */
68 #define FR_TXFF (1 << 5) /* Transmit FIFO/reg full */
69 #define FR_RXFF (1 << 6) /* Receive FIFO/reg full */
70 #define FR_TXFE (1 << 7) /* Transmit FIFO/reg empty */
72 #define UART_IBRD 0x09 /* Integer baud rate register */
73 #define IBRD_BDIVINT 0xffff /* Significant part of int. divisor value */
75 #define UART_FBRD 0x0a /* Fractional baud rate register */
76 #define FBRD_BDIVFRAC 0x3f /* Significant part of frac. divisor value */
78 #define UART_LCR_H 0x0b /* Line control register */
79 #define LCR_H_WLEN8 (0x3 << 5)
80 #define LCR_H_WLEN7 (0x2 << 5)
81 #define LCR_H_WLEN6 (0x1 << 5)
82 #define LCR_H_FEN (1 << 4) /* FIFO mode enable */
83 #define LCR_H_STP2 (1 << 3) /* 2 stop frames at the end */
84 #define LCR_H_EPS (1 << 2) /* Even parity select */
85 #define LCR_H_PEN (1 << 1) /* Parity enable */
87 #define UART_CR 0x0c /* Control register */
88 #define CR_RXE (1 << 9) /* Receive enable */
89 #define CR_TXE (1 << 8) /* Transmit enable */
90 #define CR_UARTEN (1 << 0) /* UART enable */
92 #define UART_IFLS 0x0d /* FIFO level select register */
93 #define IFLS_RX_SHIFT 3 /* RX level in bits [5:3] */
94 #define IFLS_TX_SHIFT 0 /* TX level in bits [2:0] */
95 #define IFLS_MASK 0x07 /* RX/TX level is 3 bits */
96 #define IFLS_LVL_1_8th 0 /* Interrupt at 1/8 full */
97 #define IFLS_LVL_2_8th 1 /* Interrupt at 1/4 full */
98 #define IFLS_LVL_4_8th 2 /* Interrupt at 1/2 full */
99 #define IFLS_LVL_6_8th 3 /* Interrupt at 3/4 full */
100 #define IFLS_LVL_7_8th 4 /* Interrupt at 7/8 full */
102 #define UART_IMSC 0x0e /* Interrupt mask set/clear register */
103 #define IMSC_MASK_ALL 0x7ff /* Mask all interrupts */
105 #define UART_RIS 0x0f /* Raw interrupt status register */
106 #define UART_RXREADY (1 << 4) /* RX buffer full */
107 #define UART_TXEMPTY (1 << 5) /* TX buffer empty */
108 #define RIS_RTIM (1 << 6) /* Receive timeout */
109 #define RIS_FE (1 << 7) /* Framing error interrupt status */
110 #define RIS_PE (1 << 8) /* Parity error interrupt status */
111 #define RIS_BE (1 << 9) /* Break error interrupt status */
112 #define RIS_OE (1 << 10) /* Overrun interrupt status */
114 #define UART_MIS 0x10 /* Masked interrupt status register */
115 #define UART_ICR 0x11 /* Interrupt clear register */
117 #define UART_PIDREG_0 0x3f8 /* Peripheral ID register 0 */
118 #define UART_PIDREG_1 0x3f9 /* Peripheral ID register 1 */
119 #define UART_PIDREG_2 0x3fa /* Peripheral ID register 2 */
120 #define UART_PIDREG_3 0x3fb /* Peripheral ID register 3 */
123 * The hardware FIFOs are 16 bytes each on rev 2 and earlier hardware, 32 bytes
124 * on rev 3 and later. We configure them to interrupt when 3/4 full/empty. For
125 * RX we set the size to the full hardware capacity so that the uart core
126 * allocates enough buffer space to hold a complete fifo full of incoming data.
127 * For TX, we need to limit the size to the capacity we know will be available
128 * when the interrupt occurs; uart_core will feed exactly that many bytes to
129 * uart_pl011_bus_transmit() which must consume them all.
131 #define FIFO_RX_SIZE_R2 16
132 #define FIFO_TX_SIZE_R2 12
133 #define FIFO_RX_SIZE_R3 32
134 #define FIFO_TX_SIZE_R3 24
135 #define FIFO_IFLS_BITS ((IFLS_LVL_6_8th << IFLS_RX_SHIFT) | (IFLS_LVL_2_8th))
138 * FIXME: actual register size is SoC-dependent, we need to handle it
140 #define __uart_getreg(bas, reg) \
141 bus_space_read_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg))
142 #define __uart_setreg(bas, reg, value) \
143 bus_space_write_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg), value)
146 * Low-level UART interface.
148 static int uart_pl011_probe(struct uart_bas *bas);
149 static void uart_pl011_init(struct uart_bas *bas, int, int, int, int);
150 static void uart_pl011_term(struct uart_bas *bas);
151 static void uart_pl011_putc(struct uart_bas *bas, int);
152 static int uart_pl011_rxready(struct uart_bas *bas);
153 static int uart_pl011_getc(struct uart_bas *bas, struct mtx *);
155 static struct uart_ops uart_pl011_ops = {
156 .probe = uart_pl011_probe,
157 .init = uart_pl011_init,
158 .term = uart_pl011_term,
159 .putc = uart_pl011_putc,
160 .rxready = uart_pl011_rxready,
161 .getc = uart_pl011_getc,
165 uart_pl011_probe(struct uart_bas *bas)
172 uart_pl011_param(struct uart_bas *bas, int baudrate, int databits, int stopbits,
179 * Zero all settings to make sure
180 * UART is disabled and not configured
183 __uart_setreg(bas, UART_CR, ctrl);
185 /* As we know UART is disabled we may setup the line */
210 /* Configure the rest */
211 ctrl |= (CR_RXE | CR_TXE | CR_UARTEN);
213 if (bas->rclk != 0 && baudrate != 0) {
214 baud = bas->rclk * 4 / baudrate;
215 __uart_setreg(bas, UART_IBRD, ((uint32_t)(baud >> 6)) & IBRD_BDIVINT);
216 __uart_setreg(bas, UART_FBRD, (uint32_t)(baud & 0x3F) & FBRD_BDIVFRAC);
219 /* Add config. to line before reenabling UART */
220 __uart_setreg(bas, UART_LCR_H, (__uart_getreg(bas, UART_LCR_H) &
223 /* Set rx and tx fifo levels. */
224 __uart_setreg(bas, UART_IFLS, FIFO_IFLS_BITS);
226 __uart_setreg(bas, UART_CR, ctrl);
230 uart_pl011_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
233 /* Mask all interrupts */
234 __uart_setreg(bas, UART_IMSC, __uart_getreg(bas, UART_IMSC) &
237 uart_pl011_param(bas, baudrate, databits, stopbits, parity);
241 uart_pl011_term(struct uart_bas *bas)
246 uart_pl011_putc(struct uart_bas *bas, int c)
249 /* Wait when TX FIFO full. Push character otherwise. */
250 while (__uart_getreg(bas, UART_FR) & FR_TXFF)
252 __uart_setreg(bas, UART_DR, c & 0xff);
256 uart_pl011_rxready(struct uart_bas *bas)
259 return !(__uart_getreg(bas, UART_FR) & FR_RXFE);
263 uart_pl011_getc(struct uart_bas *bas, struct mtx *hwmtx)
267 while (!uart_pl011_rxready(bas))
269 c = __uart_getreg(bas, UART_DR) & 0xff;
275 * High-level UART interface.
277 struct uart_pl011_softc {
278 struct uart_softc base;
279 uint16_t imsc; /* Interrupt mask */
282 static int uart_pl011_bus_attach(struct uart_softc *);
283 static int uart_pl011_bus_detach(struct uart_softc *);
284 static int uart_pl011_bus_flush(struct uart_softc *, int);
285 static int uart_pl011_bus_getsig(struct uart_softc *);
286 static int uart_pl011_bus_ioctl(struct uart_softc *, int, intptr_t);
287 static int uart_pl011_bus_ipend(struct uart_softc *);
288 static int uart_pl011_bus_param(struct uart_softc *, int, int, int, int);
289 static int uart_pl011_bus_probe(struct uart_softc *);
290 static int uart_pl011_bus_receive(struct uart_softc *);
291 static int uart_pl011_bus_setsig(struct uart_softc *, int);
292 static int uart_pl011_bus_transmit(struct uart_softc *);
293 static void uart_pl011_bus_grab(struct uart_softc *);
294 static void uart_pl011_bus_ungrab(struct uart_softc *);
296 static kobj_method_t uart_pl011_methods[] = {
297 KOBJMETHOD(uart_attach, uart_pl011_bus_attach),
298 KOBJMETHOD(uart_detach, uart_pl011_bus_detach),
299 KOBJMETHOD(uart_flush, uart_pl011_bus_flush),
300 KOBJMETHOD(uart_getsig, uart_pl011_bus_getsig),
301 KOBJMETHOD(uart_ioctl, uart_pl011_bus_ioctl),
302 KOBJMETHOD(uart_ipend, uart_pl011_bus_ipend),
303 KOBJMETHOD(uart_param, uart_pl011_bus_param),
304 KOBJMETHOD(uart_probe, uart_pl011_bus_probe),
305 KOBJMETHOD(uart_receive, uart_pl011_bus_receive),
306 KOBJMETHOD(uart_setsig, uart_pl011_bus_setsig),
307 KOBJMETHOD(uart_transmit, uart_pl011_bus_transmit),
308 KOBJMETHOD(uart_grab, uart_pl011_bus_grab),
309 KOBJMETHOD(uart_ungrab, uart_pl011_bus_ungrab),
314 static struct uart_class uart_pl011_class = {
317 sizeof(struct uart_pl011_softc),
318 .uc_ops = &uart_pl011_ops,
326 static struct ofw_compat_data compat_data[] = {
327 {"arm,pl011", (uintptr_t)&uart_pl011_class},
328 {NULL, (uintptr_t)NULL},
330 UART_FDT_CLASS_AND_DEVICE(compat_data);
334 static struct acpi_uart_compat_data acpi_compat_data[] = {
335 {"ARMH0011", &uart_pl011_class, ACPI_DBG2_ARM_PL011},
338 UART_ACPI_CLASS_AND_DEVICE(acpi_compat_data);
342 uart_pl011_bus_attach(struct uart_softc *sc)
344 struct uart_pl011_softc *psc;
345 struct uart_bas *bas;
347 psc = (struct uart_pl011_softc *)sc;
350 /* Enable interrupts */
351 psc->imsc = (UART_RXREADY | RIS_RTIM | UART_TXEMPTY);
352 __uart_setreg(bas, UART_IMSC, psc->imsc);
354 /* Clear interrupts */
355 __uart_setreg(bas, UART_ICR, IMSC_MASK_ALL);
361 uart_pl011_bus_detach(struct uart_softc *sc)
368 uart_pl011_bus_flush(struct uart_softc *sc, int what)
375 uart_pl011_bus_getsig(struct uart_softc *sc)
382 uart_pl011_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
387 uart_lock(sc->sc_hwmtx);
389 case UART_IOCTL_BREAK:
391 case UART_IOCTL_BAUD:
392 *(int*)data = 115200;
398 uart_unlock(sc->sc_hwmtx);
404 uart_pl011_bus_ipend(struct uart_softc *sc)
406 struct uart_pl011_softc *psc;
407 struct uart_bas *bas;
411 psc = (struct uart_pl011_softc *)sc;
414 uart_lock(sc->sc_hwmtx);
415 ints = __uart_getreg(bas, UART_MIS);
418 if (ints & (UART_RXREADY | RIS_RTIM))
419 ipend |= SER_INT_RXREADY;
421 ipend |= SER_INT_BREAK;
423 ipend |= SER_INT_OVERRUN;
424 if (ints & UART_TXEMPTY) {
426 ipend |= SER_INT_TXIDLE;
428 /* Disable TX interrupt */
429 __uart_setreg(bas, UART_IMSC, psc->imsc & ~UART_TXEMPTY);
432 uart_unlock(sc->sc_hwmtx);
438 uart_pl011_bus_param(struct uart_softc *sc, int baudrate, int databits,
439 int stopbits, int parity)
442 uart_lock(sc->sc_hwmtx);
443 uart_pl011_param(&sc->sc_bas, baudrate, databits, stopbits, parity);
444 uart_unlock(sc->sc_hwmtx);
450 uart_pl011_bus_probe(struct uart_softc *sc)
458 * The FIFO sizes vary depending on hardware; rev 2 and below have 16
459 * byte FIFOs, rev 3 and up are 32 byte. The hardware rev is in the
460 * primecell periphid register, but we get a bit of drama, as always,
461 * with the bcm2835 (rpi), which claims to be rev 3, but has 16 byte
462 * FIFOs. We check for both the old freebsd-historic and the proper
463 * bindings-defined compatible strings for bcm2835, and also check the
464 * workaround the linux drivers use for rpi3, which is to override the
465 * primecell periphid register value with a property.
467 if (ofw_bus_is_compatible(sc->sc_dev, "brcm,bcm2835-pl011") ||
468 ofw_bus_is_compatible(sc->sc_dev, "broadcom,bcm2835-uart")) {
471 node = ofw_bus_get_node(sc->sc_dev);
472 if (OF_getencprop(node, "arm,primecell-periphid", &periphid,
473 sizeof(periphid)) > 0) {
474 hwrev = (periphid >> 20) & 0x0f;
476 hwrev = __uart_getreg(&sc->sc_bas, UART_PIDREG_2) >> 4;
480 hwrev = __uart_getreg(&sc->sc_bas, UART_PIDREG_2) >> 4;
483 sc->sc_rxfifosz = FIFO_RX_SIZE_R2;
484 sc->sc_txfifosz = FIFO_TX_SIZE_R2;
486 sc->sc_rxfifosz = FIFO_RX_SIZE_R3;
487 sc->sc_txfifosz = FIFO_TX_SIZE_R3;
490 device_set_desc(sc->sc_dev, "PrimeCell UART (PL011)");
496 uart_pl011_bus_receive(struct uart_softc *sc)
498 struct uart_bas *bas;
503 uart_lock(sc->sc_hwmtx);
506 ints = __uart_getreg(bas, UART_FR);
509 if (uart_rx_full(sc)) {
510 sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
514 xc = __uart_getreg(bas, UART_DR);
518 rx |= UART_STAT_FRAMERR;
520 rx |= UART_STAT_PARERR;
525 uart_unlock(sc->sc_hwmtx);
531 uart_pl011_bus_setsig(struct uart_softc *sc, int sig)
538 uart_pl011_bus_transmit(struct uart_softc *sc)
540 struct uart_pl011_softc *psc;
541 struct uart_bas *bas;
544 psc = (struct uart_pl011_softc *)sc;
546 uart_lock(sc->sc_hwmtx);
548 for (i = 0; i < sc->sc_txdatasz; i++) {
549 __uart_setreg(bas, UART_DR, sc->sc_txbuf[i]);
553 /* Mark busy and enable TX interrupt */
555 __uart_setreg(bas, UART_IMSC, psc->imsc);
557 uart_unlock(sc->sc_hwmtx);
563 uart_pl011_bus_grab(struct uart_softc *sc)
565 struct uart_pl011_softc *psc;
566 struct uart_bas *bas;
568 psc = (struct uart_pl011_softc *)sc;
571 /* Disable interrupts on switch to polling */
572 uart_lock(sc->sc_hwmtx);
573 __uart_setreg(bas, UART_IMSC, psc->imsc & ~IMSC_MASK_ALL);
574 uart_unlock(sc->sc_hwmtx);
578 uart_pl011_bus_ungrab(struct uart_softc *sc)
580 struct uart_pl011_softc *psc;
581 struct uart_bas *bas;
583 psc = (struct uart_pl011_softc *)sc;
586 /* Switch to using interrupts while not grabbed */
587 uart_lock(sc->sc_hwmtx);
588 __uart_setreg(bas, UART_IMSC, psc->imsc);
589 uart_unlock(sc->sc_hwmtx);