On 4/23/20 11:01 AM, Geert Uytterhoeven wrote:
> Add a GPIO controller backend, to connect virtual GPIOs on the guest to
> physical GPIOs on the host. This allows the guest to control any
> external device connected to the physical GPIOs.
>
> Features and limitations:
> - The backend uses libgpiod on Linux,
> - For now only GPIO outputs are supported,
> - The number of GPIO lines mapped is limited to the number of GPIO
> lines available on the virtual GPIO controller.
>
> Future work:
> - GPIO inputs,
> - GPIO line configuration,
> - Optimizations for controlling multiple GPIO lines at once,
> - ...
>
> Signed-off-by: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> ---
> v2:
> - Drop vgpios and gpios parameters, and map the full gpiochip instead,
> - Replace hardcoded PL061 instance by multiple dynamic instances,
> registered through qemu_gpiodev_add().
> ---
> MAINTAINERS | 6 +++
> backends/Makefile.objs | 2 +
> backends/gpiodev.c | 94 ++++++++++++++++++++++++++++++++++++++++
> configure | 28 ++++++++++++
> include/sysemu/gpiodev.h | 12 +++++
> 5 files changed, 142 insertions(+)
> create mode 100644 backends/gpiodev.c
> create mode 100644 include/sysemu/gpiodev.h
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index e760f65270d29d5d..a70af47430083d14 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -607,6 +607,12 @@ F: include/hw/arm/digic.h
> F: hw/*/digic*
> F: include/hw/*/digic*
>
> +GPIO device backend
> +M: Geert Uytterhoeven <geert+renesas@xxxxxxxxx>
> +S: Supported
> +F: backends/gpiodev.c
> +F: include/sysemu/gpiodev.h
> +
> Goldfish RTC
> M: Anup Patel <anup.patel@xxxxxxx>
> M: Alistair Francis <Alistair.Francis@xxxxxxx>
> diff --git a/backends/Makefile.objs b/backends/Makefile.objs
> index 28a847cd571d96ed..ee658e797454119a 100644
> --- a/backends/Makefile.objs
> +++ b/backends/Makefile.objs
> @@ -21,3 +21,5 @@ common-obj-$(CONFIG_LINUX) += hostmem-memfd.o
> common-obj-$(CONFIG_GIO) += dbus-vmstate.o
> dbus-vmstate.o-cflags = $(GIO_CFLAGS)
> dbus-vmstate.o-libs = $(GIO_LIBS)
> +
> +common-obj-$(CONFIG_GPIODEV) += gpiodev.o
> diff --git a/backends/gpiodev.c b/backends/gpiodev.c
> new file mode 100644
> index 0000000000000000..df1bd0113c7b2985
> --- /dev/null
> +++ b/backends/gpiodev.c
> @@ -0,0 +1,94 @@
> +/*
> + * QEMU GPIO Backend
> + *
> + * Copyright (C) 2018-2020 Glider bv
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */
> +
> +#include <errno.h>
<errno.h> probably not needed.
> +#include <gpiod.h>
Please move this one...
> +
> +#include "qemu/osdep.h"
> +#include "qemu/config-file.h"
> +#include "qemu/cutils.h"
> +#include "qemu/error-report.h"
> +#include "qemu/module.h"
> +#include "qemu/option.h"
> +#include "qapi/error.h"
> +
> +#include "sysemu/gpiodev.h"
> +
> +#include "hw/irq.h"
> +#include "hw/qdev-core.h"
... here:
#include <gpiod.h>
> +
> +static void gpiodev_irq_handler(void *opaque, int n, int level)
> +{
> + struct gpiod_line *line = opaque;
> + int status;
> +
> + status = gpiod_line_set_value(line, level);
> + if (status < 0) {
> + struct gpiod_chip *chip = gpiod_line_get_chip(line);
> +
> + error_report("%s/%s: Cannot set GPIO line %u: %s",
> + gpiod_chip_name(chip), gpiod_chip_label(chip),
> + gpiod_line_offset(line), strerror(errno));
> + }
> +}
> +
> +static int gpiodev_map_line(DeviceState *dev, struct gpiod_chip *chip,
> + unsigned int gpio, Error **errp)
> +{
> + struct gpiod_line *line;
> + qemu_irq irq;
> + int status;
> +
> + line = gpiod_chip_get_line(chip, gpio);
> + if (!line) {
> + error_setg(errp, "Cannot obtain GPIO line %u: %s", gpio,
> + strerror(errno));
> + return -1;
> + }
> +
> + status = gpiod_line_request_output(line, "qemu", 0);
> + if (status < 0) {
> + error_setg(errp, "Cannot request GPIO line %u for output: %s", gpio,
> + strerror(errno));
> + return status;
> + }
> +
> + irq = qemu_allocate_irq(gpiodev_irq_handler, line, 0);
> + qdev_connect_gpio_out(dev, gpio, irq);
> + return 0;
> +}
> +
> +void qemu_gpiodev_add(DeviceState *dev, const char *name, unsigned int maxgpio,
> + Error **errp)
> +{
> + struct gpiod_chip *chip;
> + unsigned int i, n;
> + int status;
> +
> + chip = gpiod_chip_open_lookup(name);
> + if (!chip) {
> + error_setg(errp, "Cannot open GPIO chip %s: %s", name,
> + strerror(errno));
> + return;
> + }
> +
> + n = gpiod_chip_num_lines(chip);
> + if (n > maxgpio) {
> + warn_report("Last %u GPIO line(s) will not be mapped", n - maxgpio);
> + n = maxgpio;
> + }
> +
> + for (i = 0; i < n; i++) {
> + status = gpiodev_map_line(dev, chip, i, errp);
> + if (status < 0) {
> + return;
> + }
> + }
> +
> + info_report("Mapped %u GPIO lines", n);
> +}
> diff --git a/configure b/configure
> index 23b5e93752b6a259..8b133402ef727c8e 100755
> --- a/configure
> +++ b/configure
> @@ -509,6 +509,7 @@ libpmem=""
> default_devices="yes"
> plugins="no"
> fuzzing="no"
> +gpio=""
Maybe name this feature 'libgpiod'?
>
> supported_cpu="no"
> supported_os="no"
> @@ -1601,6 +1602,10 @@ for opt do
> ;;
> --gdb=*) gdb_bin="$optarg"
> ;;
> + --disable-gpio) gpio="no"
> + ;;
> + --enable-gpio) gpio="yes"
Ditto: --enable-libgpiod, because else it seems rather confusing.
> + ;;
> *)
> echo "ERROR: unknown option $opt"
> echo "Try '$0 --help' for more information"
> @@ -1894,6 +1899,7 @@ disabled with --disable-FEATURE, default is enabled if available:
> debug-mutex mutex debugging support
> libpmem libpmem support
> xkbcommon xkbcommon support
> + gpio gpio support
>
> NOTE: The object files are built at the place where configure is launched
> EOF
> @@ -6250,6 +6256,23 @@ case "$slirp" in
> ;;
> esac
>
> +##########################################
> +# check for libgpiod
> +
> +if test "$gpio" != "no"; then
> + if $pkg_config --exists "libgpiod"; then
> + gpio="yes"
> + libgpiod_libs=$($pkg_config --libs libgpiod)
> + libgpiod_cflags=$($pkg_config --cflags libgpiod)
> + libs_softmmu="$libs_softmmu $libgpiod_libs"
> + QEMU_CFLAGS="$QEMU_CFLAGS $libgpiod_cflags"
> + else
> + if test "$gpio" = "yes" ; then
> + feature_not_found "gpio" "Install libgpiod"
> + fi
> + gpio="no"
> + fi
> +fi
>
> ##########################################
> # End of CC checks
> @@ -6733,6 +6756,7 @@ echo "default devices $default_devices"
> echo "plugin support $plugins"
> echo "fuzzing support $fuzzing"
> echo "gdb $gdb_bin"
> +echo "gpio support $gpio"
>
> if test "$supported_cpu" = "no"; then
> echo
> @@ -7614,6 +7638,10 @@ if test -n "$gdb_bin" ; then
> echo "HAVE_GDB_BIN=$gdb_bin" >> $config_host_mak
> fi
>
> +if test "$gpio" = "yes" ; then
> + echo "CONFIG_GPIODEV=y" >> $config_host_mak
> +fi
> +
> if test "$tcg_interpreter" = "yes"; then
> QEMU_INCLUDES="-iquote \$(SRC_PATH)/tcg/tci $QEMU_INCLUDES"
> elif test "$ARCH" = "sparc64" ; then
> diff --git a/include/sysemu/gpiodev.h b/include/sysemu/gpiodev.h
> new file mode 100644
> index 0000000000000000..bedd141001245207
> --- /dev/null
> +++ b/include/sysemu/gpiodev.h
> @@ -0,0 +1,12 @@
> +/*
> + * QEMU GPIO Backend
> + *
> + * Copyright (C) 2018-2020 Glider bv
> + *
> + * SPDX-License-Identifier: GPL-2.0-or-later
> + */
> +
> +#include "qemu/typedefs.h"
"qemu/typedefs.h" not needed in includes.
> +
> +void qemu_gpiodev_add(DeviceState *dev, const char *name, unsigned int maxgpio,
> + Error **errp);
>
