Author: ian
Date: Mon Apr 22 04:15:22 2019
New Revision: 346522
URL: https://svnweb.freebsd.org/changeset/base/346522
Log:
MFC r336070, r336072-r336073, r336076
r336070:
Add pnp info and a module makefile for the imx_wdog watchdog driver.
r336072:
Correctly calculate the value to put in the imx wdog countdown register.
The correct value is seconds*2-1. The code was using just seconds*2, which
led to being off by a half-second -- usually not a big deal, except when the
value was the max (128) it overflowed so zero would get written to the
countdown register, which equates to a timeout of a half second.
r336073:
Add support to the imx watchdog for the FDT "timeout-sec" property, by
automatically initializing the watchdog using the given value. Also,
attach at BUS_PASS_TIMER to extend watchdog protection to more of the
kernel init process.
r336076:
Add a manpage for the imx5/6 watchdog driver.
Added:
stable/11/share/man/man4/man4.arm/imx_wdog.4
- copied unchanged from r336076, head/share/man/man4/man4.arm/imx_wdog.4
stable/11/sys/modules/imx/imx_wdog/
- copied from r336070, head/sys/modules/imx/imx_wdog/
Modified:
stable/11/share/man/man4/man4.arm/Makefile
stable/11/sys/arm/freescale/imx/imx_wdog.c
stable/11/sys/modules/imx/Makefile
Directory Properties:
stable/11/ (props changed)
Modified: stable/11/share/man/man4/man4.arm/Makefile
==============================================================================
--- stable/11/share/man/man4/man4.arm/Makefile Mon Apr 22 04:11:37 2019
(r346521)
+++ stable/11/share/man/man4/man4.arm/Makefile Mon Apr 22 04:15:22 2019
(r346522)
@@ -4,11 +4,13 @@ PACKAGE=runtime-manuals
MAN= cgem.4 \
devcfg.4 \
+ imx_wdog.4 \
mge.4 \
npe.4 \
ti_adc.4
MLINKS= cgem.4 if_cgem.4
+MLINKS+= imx_wdog.4 imxwdt.4
MLINKS+= mge.4 if_mge.4
MLINKS+=npe.4 if_npe.4
Copied: stable/11/share/man/man4/man4.arm/imx_wdog.4 (from r336076,
head/share/man/man4/man4.arm/imx_wdog.4)
==============================================================================
--- /dev/null 00:00:00 1970 (empty, because file is newly added)
+++ stable/11/share/man/man4/man4.arm/imx_wdog.4 Mon Apr 22 04:15:22
2019 (r346522, copy of r336076, head/share/man/man4/man4.arm/imx_wdog.4)
@@ -0,0 +1,112 @@
+.\"
+.\" Copyright (c) 2018 Ian Lepore <i...@freebsd.org>
+.\" All rights reserved.
+.\"
+.\" 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 ``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 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.
+.\"
+.\" $FreeBSD$
+.\"
+.Dd July 7, 2018
+.Dt IMX_WDOG 4
+.Os
+.Sh NAME
+.Nm imx_wdog
+.Nd device driver for the NXP i.MX5 and i.MX6 watchdog timer
+.Sh SYNOPSIS
+To compile this driver into the kernel,
+place the following line in your
+kernel configuration file:
+.Bd -ragged -offset indent
+.Cd "device imxwdt"
+.Ed
+.Pp
+Alternatively, to load the driver as a
+module at boot time, place the following line in
+.Xr loader.conf 5 :
+.Bd -literal -offset indent
+imx_wdog_load="YES"
+.Ed
+.Sh DESCRIPTION
+The
+.Nm
+driver provides
+.Xr watchdog 4
+support for the watchdog timer present on NXP i.MX5 and i.MX6 processors.
+The i.MX watchdog hardware supports programmable timeouts ranging from
+0.5 to 128 seconds, in half-second increments.
+Once activated, the watchdog hardware cannot be deactivated, but the
+timeout period can be changed to any valid non-zero value.
+.Pp
+At power-on, a special 16-second
+.Sq power-down timer
+mode is automatically enabled by the hardware.
+It will assert the external WDOG_B signal, which may be connected to
+external hardware that causes the system to reset or power-down.
+The power-down timer is often reset by the boot loader (typically U-Boot).
+If the power-down timer is still active at the time when the normal
+watchdog is first enabled, the
+.Nm
+driver automatically disables it.
+.Pp
+The
+.Nm
+driver supports the FDT
+.Va fsl,external-reset
+property by enabling the assertion of the WDOG_B external timeout signal
+when the property is present.
+When running this way, the need to reset the system due to watchdog
+timeout is signaled by driving the WDOG_B line low; some external
+entity is expected to assert the chip's POR pin in response.
+The
+.Nm
+driver attempts to backstop this external reset by scheduling an
+interrupt to occur as well.
+The interrupt handler waits 1 second for the external reset to occur,
+then it triggers a normal software reset.
+Note that the WDOG_B signal can be configured to use a variety of
+pins on the chip.
+For the
+.Va fsl,external-reset
+property to be effective, the signal must be connected to an appropriate
+pin by the system's FDT pinctrl data.
+.Pp
+The
+.Nm
+driver supports the FDT
+.Va timeout-secs
+property by enabling the watchdog as soon as the driver attaches,
+using the given timeout value.
+This extends watchdog protection to much of the system startup process,
+but it still requires that
+.Xr watchdogd 4
+be configured to service the watchdog.
+.Sh SEE ALSO
+.Xr fdt 4 ,
+.Xr watchdog 4 ,
+.Xr watchdog 8 ,
+.Xr watchdogd 8 ,
+.Xr watchdog 9
+.Sh HISTORY
+The
+.Nm
+driver first appeared in
+.Fx 10.0 .
Modified: stable/11/sys/arm/freescale/imx/imx_wdog.c
==============================================================================
--- stable/11/sys/arm/freescale/imx/imx_wdog.c Mon Apr 22 04:11:37 2019
(r346521)
+++ stable/11/sys/arm/freescale/imx/imx_wdog.c Mon Apr 22 04:15:22 2019
(r346522)
@@ -97,43 +97,52 @@ WR2(struct imx_wdog_softc *sc, bus_size_t offs, uint16
bus_write_2(sc->sc_res[MEMRES], offs, val);
}
+static int
+imx_wdog_enable(struct imx_wdog_softc *sc, u_int timeout)
+{
+ uint16_t reg;
+
+ if (timeout < 1 || timeout > 128)
+ return (EINVAL);
+
+ mtx_lock(&sc->sc_mtx);
+ if (timeout != sc->sc_timeout) {
+ sc->sc_timeout = timeout;
+ reg = RD2(sc, WDOG_CR_REG);
+ reg &= ~WDOG_CR_WT_MASK;
+ reg |= ((2 * timeout - 1) << WDOG_CR_WT_SHIFT);
+ WR2(sc, WDOG_CR_REG, reg | WDOG_CR_WDE);
+ }
+ /* Refresh counter */
+ WR2(sc, WDOG_SR_REG, WDOG_SR_STEP1);
+ WR2(sc, WDOG_SR_REG, WDOG_SR_STEP2);
+ /* Watchdog active, can disable rom-boot watchdog. */
+ if (sc->sc_pde_enabled) {
+ sc->sc_pde_enabled = false;
+ reg = RD2(sc, WDOG_MCR_REG);
+ WR2(sc, WDOG_MCR_REG, reg & ~WDOG_MCR_PDE);
+ }
+ mtx_unlock(&sc->sc_mtx);
+
+ return (0);
+}
+
static void
imx_watchdog(void *arg, u_int cmd, int *error)
{
struct imx_wdog_softc *sc;
- uint16_t reg;
u_int timeout;
sc = arg;
- mtx_lock(&sc->sc_mtx);
if (cmd == 0) {
if (bootverbose)
device_printf(sc->sc_dev, "Can not be disabled.\n");
*error = EOPNOTSUPP;
} else {
timeout = (u_int)((1ULL << (cmd & WD_INTERVAL)) / 1000000000U);
- if (timeout > 1 && timeout < 128) {
- if (timeout != sc->sc_timeout) {
- sc->sc_timeout = timeout;
- reg = RD2(sc, WDOG_CR_REG);
- reg &= ~WDOG_CR_WT_MASK;
- reg |= (timeout << (WDOG_CR_WT_SHIFT + 1)) &
- WDOG_CR_WT_MASK;
- WR2(sc, WDOG_CR_REG, reg | WDOG_CR_WDE);
- }
- /* Refresh counter */
- WR2(sc, WDOG_SR_REG, WDOG_SR_STEP1);
- WR2(sc, WDOG_SR_REG, WDOG_SR_STEP2);
- /* Watchdog active, can disable rom-boot watchdog. */
- if (sc->sc_pde_enabled) {
- sc->sc_pde_enabled = false;
- reg = RD2(sc, WDOG_MCR_REG);
- WR2(sc, WDOG_MCR_REG, reg & ~WDOG_MCR_PDE);
- }
+ if (imx_wdog_enable(sc, timeout) == 0)
*error = 0;
- }
}
- mtx_unlock(&sc->sc_mtx);
}
static int
@@ -175,6 +184,7 @@ static int
imx_wdog_attach(device_t dev)
{
struct imx_wdog_softc *sc;
+ pcell_t timeout;
sc = device_get_softc(dev);
sc->sc_dev = dev;
@@ -208,6 +218,26 @@ imx_wdog_attach(device_t dev)
sc->sc_pde_enabled = true;
EVENTHANDLER_REGISTER(watchdog_list, imx_watchdog, sc, 0);
+
+ /* If there is a timeout-sec property, activate the watchdog. */
+ if (OF_getencprop(ofw_bus_get_node(sc->sc_dev), "timeout-sec",
+ &timeout, sizeof(timeout)) == sizeof(timeout)) {
+ if (timeout < 1 || timeout > 128) {
+ device_printf(sc->sc_dev, "ERROR: bad timeout-sec "
+ "property value %u, using 128\n", timeout);
+ timeout = 128;
+ }
+ imx_wdog_enable(sc, timeout);
+ device_printf(sc->sc_dev, "watchdog enabled using "
+ "timeout-sec property value %u\n", timeout);
+ }
+
+ /*
+ * The watchdog hardware cannot be disabled, so there's little point in
+ * coding up a detach() routine to carefully tear everything down, just
+ * make the device busy so that detach can't happen.
+ */
+ device_busy(sc->sc_dev);
return (0);
}
@@ -225,4 +255,6 @@ static driver_t imx_wdog_driver = {
static devclass_t imx_wdog_devclass;
-DRIVER_MODULE(imx_wdog, simplebus, imx_wdog_driver, imx_wdog_devclass, 0, 0);
+EARLY_DRIVER_MODULE(imx_wdog, simplebus, imx_wdog_driver,
+ imx_wdog_devclass, 0, 0, BUS_PASS_TIMER);
+SIMPLEBUS_PNP_INFO(compat_data);
Modified: stable/11/sys/modules/imx/Makefile
==============================================================================
--- stable/11/sys/modules/imx/Makefile Mon Apr 22 04:11:37 2019
(r346521)
+++ stable/11/sys/modules/imx/Makefile Mon Apr 22 04:15:22 2019
(r346522)
@@ -5,5 +5,6 @@ SUBDIR = \
../ffec \
imx_i2c \
imx_spi \
+ imx_wdog \
.include <bsd.subdir.mk>
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