svn commit: r334997 - in head/sys: arm64/conf conf dev/uart modules/uart
Diane Bruce
db at FreeBSD.org
Tue Jun 12 13:26:33 UTC 2018
Author: db (ports committer)
Date: Tue Jun 12 13:26:31 2018
New Revision: 334997
URL: https://svnweb.freebsd.org/changeset/base/334997
Log:
Add a driver for the BCM2835 Mini-UART as seen on the RPi3
Reviewed by: andrew
Approved by: andrew
Differential Revision: https://reviews.freebsd.org/D15684
Added:
head/sys/dev/uart/uart_dev_mu.c (contents, props changed)
Modified:
head/sys/arm64/conf/GENERIC (contents, props changed)
head/sys/conf/files.arm64 (contents, props changed)
head/sys/modules/uart/Makefile (contents, props changed)
Modified: head/sys/arm64/conf/GENERIC
==============================================================================
--- head/sys/arm64/conf/GENERIC Tue Jun 12 11:47:21 2018 (r334996)
+++ head/sys/arm64/conf/GENERIC Tue Jun 12 13:26:31 2018 (r334997)
@@ -165,6 +165,7 @@ device dwmmc
# Serial (COM) ports
device uart # Generic UART driver
device uart_msm # Qualcomm MSM UART driver
+device uart_mu # RPI3 aux port
device uart_mvebu # Armada 3700 UART driver
device uart_ns8250 # ns8250-type UART driver
device uart_snps
Modified: head/sys/conf/files.arm64
==============================================================================
--- head/sys/conf/files.arm64 Tue Jun 12 11:47:21 2018 (r334996)
+++ head/sys/conf/files.arm64 Tue Jun 12 13:26:31 2018 (r334997)
@@ -209,6 +209,7 @@ dev/pci/pci_host_generic_fdt.c optional pci fdt
dev/psci/psci.c standard
dev/psci/psci_arm64.S standard
dev/uart/uart_cpu_arm64.c optional uart
+dev/uart/uart_dev_mu.c optional uart uart_mu
dev/uart/uart_dev_pl011.c optional uart pl011
dev/usb/controller/dwc_otg_hisi.c optional dwcotg fdt soc_hisi_hi6220
dev/usb/controller/ehci_mv.c optional ehci_mv fdt
Added: head/sys/dev/uart/uart_dev_mu.c
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ head/sys/dev/uart/uart_dev_mu.c Tue Jun 12 13:26:31 2018 (r334997)
@@ -0,0 +1,521 @@
+/*-
+ * Copyright (c) 2018 Diane Bruce
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+/*
+ * Based on uart_dev_pl011.c
+ * Copyright (c) 2012 Semihalf.
+ * All rights reserved.
+ */
+/*
+ * The mini Uart has the following features:
+ * - 7 or 8 bit operation.
+ * - 1 start and 1 stop bit.
+ * - No parities.
+ * - Break generation.
+ * - 8 symbols deep FIFOs for receive and transmit.
+ * - SW controlled RTS, SW readable CTS.
+ * - Auto flow control with programmable FIFO level.
+ * - 16550 like registers.
+ * - Baudrate derived from system clock.
+ * This is a mini UART and it does NOT have the following capabilities:
+ * - Break detection
+ * - Framing errors detection.
+ * - Parity bit
+ * - Receive Time-out interrupt
+ * - DCD, DSR, DTR or RI signals.
+ * The implemented UART is not a 16650 compatible UART However as far
+ * as possible the first 8 control and status registers are laid out
+ * like a 16550 UART. All 16550 register bits which are not supported can
+ * be written but will be ignored and read back as 0. All control bits
+ * for simple UART receive/transmit operations are available.
+ */
+
+#include "opt_acpi.h"
+#include "opt_platform.h"
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/systm.h>
+#include <sys/kernel.h>
+#include <sys/bus.h>
+
+#include <machine/bus.h>
+#include <machine/machdep.h>
+#include <machine/pcpu.h>
+
+#include <dev/uart/uart.h>
+#include <dev/uart/uart_cpu.h>
+#ifdef FDT
+#include <dev/uart/uart_cpu_fdt.h>
+#include <dev/ofw/ofw_bus.h>
+#endif
+#include <dev/uart/uart_bus.h>
+#include "uart_if.h"
+
+/* BCM2835 Micro UART registers and masks*/
+#define AUX_MU_IO_REG 0x00 /* I/O register */
+
+/*
+ * According to errata bits 1 and 2 are swapped,
+ * Also bits 2 and 3 are required to enable interrupts.
+ */
+#define AUX_MU_IER_REG 0x01
+#define IER_RXENABLE (1)
+#define IER_TXENABLE (1<<1)
+#define IER_REQUIRED (3<<2)
+#define IER_MASK_ALL (IER_TXENABLE|IER_RXENABLE)
+
+#define AUX_MU_IIR_REG 0x02
+#define IIR_READY (1)
+#define IIR_TXREADY (1<<1)
+#define IIR_RXREADY (1<<2)
+#define IIR_CLEAR (3<<1)
+
+#define AUX_MU_LCR_REG 0x03
+#define LCR_WLEN7 (0)
+#define LCR_WLEN8 (3)
+
+#define AUX_MU_MCR_REG 0x04
+#define AUX_MCR_RTS (1<<1)
+
+#define AUX_MU_LSR_REG 0x05
+#define LSR_RXREADY (1)
+#define LSR_OVRRUN (1<<1)
+#define LSR_TXEMPTY (1<<5)
+#define LSR_TXIDLE (1<<6)
+
+#define AUX_MU_MSR_REG 0x06
+#define MSR_CTS (1<<5)
+
+#define AUX_MU_SCRATCH_REG 0x07
+
+#define AUX_MU_CNTL_REG 0x08
+#define CNTL_RXENAB (1)
+#define CNTL_TXENAB (1<<1)
+
+#define AUX_MU_STAT_REG 0x09
+#define STAT_TX_SA (1<<1)
+#define STAT_RX_SA (1)
+
+#define AUX_MU_BAUD_REG 0x0a
+
+/*
+ * FIXME: actual register size is SoC-dependent, we need to handle it
+ */
+#define __uart_getreg(bas, reg) \
+ bus_space_read_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg))
+#define __uart_setreg(bas, reg, value) \
+ bus_space_write_4((bas)->bst, (bas)->bsh, uart_regofs(bas, reg), value)
+
+/*
+ * Low-level UART interface.
+ */
+static int uart_mu_probe(struct uart_bas *bas);
+static void uart_mu_init(struct uart_bas *bas, int, int, int, int);
+static void uart_mu_term(struct uart_bas *bas);
+static void uart_mu_putc(struct uart_bas *bas, int);
+static int uart_mu_rxready(struct uart_bas *bas);
+static int uart_mu_getc(struct uart_bas *bas, struct mtx *);
+
+static struct uart_ops uart_mu_ops = {
+ .probe = uart_mu_probe,
+ .init = uart_mu_init,
+ .term = uart_mu_term,
+ .putc = uart_mu_putc,
+ .rxready = uart_mu_rxready,
+ .getc = uart_mu_getc,
+};
+
+static int
+uart_mu_probe(struct uart_bas *bas)
+{
+
+ return (0);
+}
+
+/*
+ * According to the docs, the cpu clock is locked to 250Mhz when
+ * the micro-uart is used
+ */
+#define CPU_CLOCK 250000000
+
+static void
+uart_mu_param(struct uart_bas *bas, int baudrate, int databits, int stopbits,
+ int parity)
+{
+ uint32_t line;
+ uint32_t baud;
+
+ /*
+ * Zero all settings to make sure
+ * UART is disabled and not configured
+ */
+ line = 0x0;
+ __uart_setreg(bas, AUX_MU_CNTL_REG, line);
+
+ /* As I know UART is disabled I can setup the line */
+ switch (databits) {
+ case 7:
+ line |= LCR_WLEN7;
+ break;
+ case 6:
+ case 8:
+ default:
+ line |= LCR_WLEN8;
+ break;
+ }
+
+ __uart_setreg(bas, AUX_MU_LCR_REG, line);
+
+ /* See 2.2.1 BCM2835-ARM-Peripherals baudrate */
+ if (baudrate != 0) {
+ baud = CPU_CLOCK / (8 * baudrate);
+ /* XXX
+ * baud = cpu_clock() / (8 * baudrate);
+ */
+ __uart_setreg(bas, AUX_MU_BAUD_REG, ((uint32_t)(baud & 0xFFFF)));
+ }
+
+ /* re-enable UART */
+ __uart_setreg(bas, AUX_MU_CNTL_REG, CNTL_RXENAB|CNTL_TXENAB);
+}
+
+static void
+uart_mu_init(struct uart_bas *bas, int baudrate, int databits, int stopbits,
+ int parity)
+{
+
+ /* Mask all interrupts */
+ __uart_setreg(bas, AUX_MU_IER_REG, 0);
+ uart_mu_param(bas, baudrate, databits, stopbits, parity);
+}
+
+static void
+uart_mu_term(struct uart_bas *bas)
+{
+}
+
+static void
+uart_mu_putc(struct uart_bas *bas, int c)
+{
+
+ /* Wait when TX FIFO full. Push character otherwise. */
+ while ((__uart_getreg(bas, AUX_MU_LSR_REG) & LSR_TXEMPTY) == 0)
+ ;
+ __uart_setreg(bas, AUX_MU_IO_REG, c & 0xff);
+}
+
+static int
+uart_mu_rxready(struct uart_bas *bas)
+{
+
+ return ((__uart_getreg(bas, AUX_MU_LSR_REG) & LSR_RXREADY) != 0);
+}
+
+static int
+uart_mu_getc(struct uart_bas *bas, struct mtx *hwmtx)
+{
+ int c;
+
+ while(!uart_mu_rxready(bas))
+ ;
+ c = __uart_getreg(bas, AUX_MU_IO_REG) & 0xff;
+ return (c);
+}
+
+/*
+ * High-level UART interface.
+ */
+struct uart_mu_softc {
+ struct uart_softc bas;
+ uint16_t aux_ier; /* Interrupt mask */
+};
+
+static int uart_mu_bus_attach(struct uart_softc *);
+static int uart_mu_bus_detach(struct uart_softc *);
+static int uart_mu_bus_flush(struct uart_softc *, int);
+static int uart_mu_bus_getsig(struct uart_softc *);
+static int uart_mu_bus_ioctl(struct uart_softc *, int, intptr_t);
+static int uart_mu_bus_ipend(struct uart_softc *);
+static int uart_mu_bus_param(struct uart_softc *, int, int, int, int);
+static int uart_mu_bus_probe(struct uart_softc *);
+static int uart_mu_bus_receive(struct uart_softc *);
+static int uart_mu_bus_setsig(struct uart_softc *, int);
+static int uart_mu_bus_transmit(struct uart_softc *);
+static void uart_mu_bus_grab(struct uart_softc *);
+static void uart_mu_bus_ungrab(struct uart_softc *);
+
+static kobj_method_t uart_mu_methods[] = {
+ KOBJMETHOD(uart_attach, uart_mu_bus_attach),
+ KOBJMETHOD(uart_detach, uart_mu_bus_detach),
+ KOBJMETHOD(uart_flush, uart_mu_bus_flush),
+ KOBJMETHOD(uart_getsig, uart_mu_bus_getsig),
+ KOBJMETHOD(uart_ioctl, uart_mu_bus_ioctl),
+ KOBJMETHOD(uart_ipend, uart_mu_bus_ipend),
+ KOBJMETHOD(uart_param, uart_mu_bus_param),
+ KOBJMETHOD(uart_probe, uart_mu_bus_probe),
+ KOBJMETHOD(uart_receive, uart_mu_bus_receive),
+ KOBJMETHOD(uart_setsig, uart_mu_bus_setsig),
+ KOBJMETHOD(uart_transmit, uart_mu_bus_transmit),
+ KOBJMETHOD(uart_grab, uart_mu_bus_grab),
+ KOBJMETHOD(uart_ungrab, uart_mu_bus_ungrab),
+
+ { 0, 0 }
+};
+
+static struct uart_class uart_mu_class = {
+ "aux-uart",
+ uart_mu_methods,
+ sizeof(struct uart_mu_softc),
+ .uc_ops = &uart_mu_ops,
+ .uc_range = 0x48,
+ .uc_rclk = 0,
+ .uc_rshift = 2
+};
+
+#ifdef FDT
+static struct ofw_compat_data fdt_compat_data[] = {
+ {"brcm,bcm2835-aux-uart" , (uintptr_t)&uart_mu_class},
+ {NULL, (uintptr_t)NULL},
+};
+UART_FDT_CLASS_AND_DEVICE(fdt_compat_data);
+#endif
+
+static int
+uart_mu_bus_attach(struct uart_softc *sc)
+{
+ struct uart_mu_softc *psc;
+ struct uart_bas *bas;
+
+ psc = (struct uart_mu_softc *)sc;
+ bas = &sc->sc_bas;
+ /* Clear interrupts */
+ __uart_setreg(bas, AUX_MU_IIR_REG, IIR_CLEAR);
+ /* Enable interrupts */
+ psc->aux_ier = (IER_RXENABLE|IER_TXENABLE|IER_REQUIRED);
+ __uart_setreg(bas, AUX_MU_IER_REG, psc->aux_ier);
+ sc->sc_txbusy = 0;
+
+ return (0);
+}
+
+static int
+uart_mu_bus_detach(struct uart_softc *sc)
+{
+
+ return (0);
+}
+
+static int
+uart_mu_bus_flush(struct uart_softc *sc, int what)
+{
+
+ return (0);
+}
+
+static int
+uart_mu_bus_getsig(struct uart_softc *sc)
+{
+
+ return (0);
+}
+
+static int
+uart_mu_bus_ioctl(struct uart_softc *sc, int request, intptr_t data)
+{
+ struct uart_bas *bas;
+ int error;
+
+ bas = &sc->sc_bas;
+ error = 0;
+ uart_lock(sc->sc_hwmtx);
+ switch (request) {
+ case UART_IOCTL_BREAK:
+ break;
+ case UART_IOCTL_BAUD:
+ *(int*)data = 115200;
+ break;
+ default:
+ error = EINVAL;
+ break;
+ }
+ uart_unlock(sc->sc_hwmtx);
+
+ return (error);
+}
+
+static int
+uart_mu_bus_ipend(struct uart_softc *sc)
+{
+ struct uart_mu_softc *psc;
+ struct uart_bas *bas;
+ uint32_t ints;
+ int ipend;
+
+ psc = (struct uart_mu_softc *)sc;
+ bas = &sc->sc_bas;
+
+ uart_lock(sc->sc_hwmtx);
+ ints = __uart_getreg(bas, AUX_MU_IIR_REG);
+ ipend = 0;
+
+ /*
+ * According to docs only one of IIR_RXREADY
+ * or IIR_TXREADY are valid eg. Only one or the other.
+ */
+ if (ints & IIR_RXREADY) {
+ ipend |= SER_INT_RXREADY;
+ } else if (ints & IIR_TXREADY) {
+ if (__uart_getreg(bas, AUX_MU_LSR_REG) & LSR_TXIDLE) {
+ if (sc->sc_txbusy)
+ ipend |= SER_INT_TXIDLE;
+
+ /* Disable TX interrupt */
+ __uart_setreg(bas, AUX_MU_IER_REG,
+ psc->aux_ier & ~IER_TXENABLE);
+ }
+ }
+
+ uart_unlock(sc->sc_hwmtx);
+
+ return (ipend);
+}
+
+static int
+uart_mu_bus_param(struct uart_softc *sc, int baudrate, int databits,
+ int stopbits, int parity)
+{
+
+ uart_lock(sc->sc_hwmtx);
+ uart_mu_param(&sc->sc_bas, baudrate, databits, stopbits, parity);
+ uart_unlock(sc->sc_hwmtx);
+
+ return (0);
+}
+
+static int
+uart_mu_bus_probe(struct uart_softc *sc)
+{
+
+ /* MU always has 8 byte deep fifo */
+ sc->sc_rxfifosz = 8;
+ sc->sc_txfifosz = 8;
+ device_set_desc(sc->sc_dev, "BCM2835 Mini-UART");
+
+ return (0);
+}
+
+static int
+uart_mu_bus_receive(struct uart_softc *sc)
+{
+ struct uart_mu_softc *psc;
+ struct uart_bas *bas;
+ uint32_t lsr, xc;
+ int rx;
+
+ bas = &sc->sc_bas;
+ uart_lock(sc->sc_hwmtx);
+ psc = (struct uart_mu_softc *)sc;
+
+ lsr = __uart_getreg(bas, AUX_MU_LSR_REG);
+ while (lsr & LSR_RXREADY) {
+ xc = __uart_getreg(bas, AUX_MU_IO_REG);
+ rx = xc & 0xff;
+ if (uart_rx_full(sc)) {
+ sc->sc_rxbuf[sc->sc_rxput] = UART_STAT_OVERRUN;
+ break;
+ }
+ uart_rx_put(sc, rx);
+ lsr = __uart_getreg(bas, AUX_MU_LSR_REG);
+ }
+ uart_unlock(sc->sc_hwmtx);
+
+ return (0);
+}
+
+static int
+uart_mu_bus_setsig(struct uart_softc *sc, int sig)
+{
+
+ return (0);
+}
+
+static int
+uart_mu_bus_transmit(struct uart_softc *sc)
+{
+ struct uart_mu_softc *psc;
+ struct uart_bas *bas;
+ int i;
+
+ psc = (struct uart_mu_softc *)sc;
+ bas = &sc->sc_bas;
+ uart_lock(sc->sc_hwmtx);
+
+ for (i = 0; i < sc->sc_txdatasz; i++) {
+ __uart_setreg(bas, AUX_MU_IO_REG, sc->sc_txbuf[i] & 0xff);
+ uart_barrier(bas);
+ }
+
+ /* Mark busy and enable TX interrupt */
+ sc->sc_txbusy = 1;
+ __uart_setreg(bas, AUX_MU_IER_REG, psc->aux_ier);
+
+ uart_unlock(sc->sc_hwmtx);
+
+ return (0);
+}
+
+static void
+uart_mu_bus_grab(struct uart_softc *sc)
+{
+ struct uart_mu_softc *psc;
+ struct uart_bas *bas;
+
+ psc = (struct uart_mu_softc *)sc;
+ bas = &sc->sc_bas;
+
+ /* Disable interrupts on switch to polling */
+ uart_lock(sc->sc_hwmtx);
+ __uart_setreg(bas, AUX_MU_IER_REG, psc->aux_ier &~IER_MASK_ALL);
+ uart_unlock(sc->sc_hwmtx);
+}
+
+static void
+uart_mu_bus_ungrab(struct uart_softc *sc)
+{
+ struct uart_mu_softc *psc;
+ struct uart_bas *bas;
+
+ psc = (struct uart_mu_softc *)sc;
+ bas = &sc->sc_bas;
+
+ /* Switch to using interrupts while not grabbed */
+ uart_lock(sc->sc_hwmtx);
+ __uart_setreg(bas, AUX_MU_CNTL_REG, CNTL_RXENAB|CNTL_TXENAB);
+ __uart_setreg(bas, AUX_MU_IER_REG, psc->aux_ier);
+ uart_unlock(sc->sc_hwmtx);
+}
Modified: head/sys/modules/uart/Makefile
==============================================================================
--- head/sys/modules/uart/Makefile Tue Jun 12 11:47:21 2018 (r334996)
+++ head/sys/modules/uart/Makefile Tue Jun 12 13:26:31 2018 (r334997)
@@ -23,14 +23,15 @@ uart_cpu_machine= ${_uart_cpu}
.if ${MACHINE} == "arm64"
uart_dev_mvebu=uart_dev_mvebu.c
+uart_dev_mu=uart_dev_mu.c
.endif
KMOD= uart
SRCS= uart_bus_acpi.c ${uart_bus_ebus} uart_bus_isa.c uart_bus_pccard.c \
uart_bus_pci.c uart_bus_puc.c uart_bus_scc.c \
uart_core.c ${uart_cpu_machine} uart_dbg.c \
- ${uart_dev_mvebu} uart_dev_ns8250.c uart_dev_quicc.c \
- uart_dev_sab82532.c uart_dev_z8530.c \
+ ${uart_dev_mvebu} uart_dev_ns8250.c ${uart_dev_mu} \
+ uart_dev_quicc.c uart_dev_sab82532.c uart_dev_z8530.c \
uart_if.c uart_if.h uart_subr.c uart_tty.c
SRCS+= acpi_if.h bus_if.h card_if.h device_if.h isa_if.h ${ofw_bus_if} \
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