| Message ID | 20200423090118.11199-4-geert+renesas@glider.be (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | Add a GPIO backend | expand |
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@glider.be> > --- > 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@glider.be> > +S: Supported > +F: backends/gpiodev.c > +F: include/sysemu/gpiodev.h > + > Goldfish RTC > M: Anup Patel <anup.patel@wdc.com> > M: Alistair Francis <Alistair.Francis@wdc.com> > 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); >
Hi Philippe, Thanks for your comments! On Thu, Apr 23, 2020 at 11:28 AM Philippe Mathieu-Daudé <f4bug@amsat.org> wrote: > 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@glider.be> > > --- /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. It is indeed included by one of the other header files. What is the QEMU policy w.r.t. that? > > > +#include <gpiod.h> > > Please move this one... > > > + > > +#include "qemu/osdep.h" > > +#include "qemu/config-file.h" > > +#include "qemu/cutils.h" I forgot to remove the two above... > > +#include "qemu/error-report.h" > > +#include "qemu/module.h" > > +#include "qemu/option.h" ... and the two above. > > +#include "qapi/error.h" > > + > > +#include "sysemu/gpiodev.h" > > + > > +#include "hw/irq.h" > > +#include "hw/qdev-core.h" > > ... here: > > #include <gpiod.h> OK. > > --- a/configure > > +++ b/configure > > @@ -509,6 +509,7 @@ libpmem="" > > default_devices="yes" > > plugins="no" > > fuzzing="no" > > +gpio="" > > Maybe name this feature 'libgpiod'? Makes sense. > > > > 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. OK. > > --- /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. While removing that works, it does mean the header file is no longer self-contained: include/sysemu/gpiodev.h:10:23: error: unknown type name ‘DeviceState’ > > + > > +void qemu_gpiodev_add(DeviceState *dev, const char *name, unsigned int maxgpio, > > + Error **errp); Gr{oetje,eeting}s, Geert
On 4/23/20 11:41 AM, Geert Uytterhoeven wrote: > Hi Philippe, > > Thanks for your comments! > > On Thu, Apr 23, 2020 at 11:28 AM Philippe Mathieu-Daudé <f4bug@amsat.org> wrote: >> 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@glider.be> > >>> --- /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. > > It is indeed included by one of the other header files. > What is the QEMU policy w.r.t. that? See CODING_STYLE.rst: Include directives ------------------ Order include directives as follows: .. code-block:: c #include "qemu/osdep.h" /* Always first... */ #include <...> /* then system headers... */ #include "..." /* and finally QEMU headers. */ The "qemu/osdep.h" header contains preprocessor macros that affect the behavior of core system headers like <stdint.h>. It must be the first include so that core system headers included by external libraries get the preprocessor macros that QEMU depends on. > >> >>> +#include <gpiod.h> >> >> Please move this one... >> >>> + >>> +#include "qemu/osdep.h" >>> +#include "qemu/config-file.h" >>> +#include "qemu/cutils.h" > > I forgot to remove the two above... > >>> +#include "qemu/error-report.h" >>> +#include "qemu/module.h" >>> +#include "qemu/option.h" > > ... and the two above. > >>> +#include "qapi/error.h" >>> + >>> +#include "sysemu/gpiodev.h" >>> + >>> +#include "hw/irq.h" >>> +#include "hw/qdev-core.h" >> >> ... here: >> >> #include <gpiod.h> > > OK. > >>> --- a/configure >>> +++ b/configure >>> @@ -509,6 +509,7 @@ libpmem="" >>> default_devices="yes" >>> plugins="no" >>> fuzzing="no" >>> +gpio="" >> >> Maybe name this feature 'libgpiod'? > > Makes sense. > >>> >>> 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. > > OK. > >>> --- /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. > > While removing that works, it does mean the header file is no longer > self-contained: > > include/sysemu/gpiodev.h:10:23: error: unknown type name ‘DeviceState’ Odd, because your backends/gpiodev.c already has: #include "hw/qdev-core.h" > >>> + >>> +void qemu_gpiodev_add(DeviceState *dev, const char *name, unsigned int maxgpio, >>> + Error **errp); > > Gr{oetje,eeting}s, > > Geert >
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@glider.be> +S: Supported +F: backends/gpiodev.c +F: include/sysemu/gpiodev.h + Goldfish RTC M: Anup Patel <anup.patel@wdc.com> M: Alistair Francis <Alistair.Francis@wdc.com> 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> +#include <gpiod.h> + +#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" + +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="" 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" + ;; *) 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" + +void qemu_gpiodev_add(DeviceState *dev, const char *name, unsigned int maxgpio, + Error **errp);
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@glider.be> --- 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