| Message ID | e2744439a0734b1426a91de9d8ccc5d749d96479.1744350629.git.koichiro.den@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | Introduce configfs-based interface for gpio-aggregator (LP: #2103496) | expand |
On Fri, Apr 11, 2025 at 04:26:23PM GMT, Koichiro Den wrote: > BugLink: https://bugs.launchpad.net/bugs/2103496 > > Both gpio-sim and gpio-virtuser share a mechanism to instantiate a > platform device, wait for probe completion, and retrieve the probe > success or error status synchronously. With gpio-aggregator planned to > adopt this approach for its configfs interface, it's time to factor > out the common code. > > Add dev-sync-probe.[ch] to house helper functions used by all such > implementations. > > No functional change. > > Signed-off-by: Koichiro Den <koichiro.den@canonical.com> > Link: https://lore.kernel.org/r/20250221133501.2203897-2-koichiro.den@canonical.com > (cherry picked from commit eb5ab6ffb4ca2d28121455dd7452061367ed5588) > Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org> This is an error, SOB must be mine. The same applies to [SRU][N/J][PATCH 01/12]. > --- > drivers/gpio/Kconfig | 3 ++ > drivers/gpio/Makefile | 3 ++ > drivers/gpio/dev-sync-probe.c | 97 +++++++++++++++++++++++++++++++++++ > drivers/gpio/dev-sync-probe.h | 25 +++++++++ > 4 files changed, 128 insertions(+) > create mode 100644 drivers/gpio/dev-sync-probe.c > create mode 100644 drivers/gpio/dev-sync-probe.h > > diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig > index 2be612f9ce55..21ac40bde9c4 100644 > --- a/drivers/gpio/Kconfig > +++ b/drivers/gpio/Kconfig > @@ -1935,3 +1935,6 @@ config GPIO_VIRTUSER > endmenu > > endif > + > +config DEV_SYNC_PROBE > + tristate > diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile > index e6b6355c66d4..a18cf557eca6 100644 > --- a/drivers/gpio/Makefile > +++ b/drivers/gpio/Makefile > @@ -19,6 +19,9 @@ obj-$(CONFIG_GPIO_GENERIC) += gpio-generic.o > # directly supported by gpio-generic > gpio-generic-$(CONFIG_GPIO_GENERIC) += gpio-mmio.o > > +# Utilities for drivers that need synchronous fake device creation > +obj-$(CONFIG_DEV_SYNC_PROBE) += dev-sync-probe.o > + > obj-$(CONFIG_GPIO_104_DIO_48E) += gpio-104-dio-48e.o > obj-$(CONFIG_GPIO_104_IDI_48) += gpio-104-idi-48.o > obj-$(CONFIG_GPIO_104_IDIO_16) += gpio-104-idio-16.o > diff --git a/drivers/gpio/dev-sync-probe.c b/drivers/gpio/dev-sync-probe.c > new file mode 100644 > index 000000000000..9ea733b863b2 > --- /dev/null > +++ b/drivers/gpio/dev-sync-probe.c > @@ -0,0 +1,97 @@ > +// SPDX-License-Identifier: GPL-2.0-or-later > +/* > + * Common code for drivers creating fake platform devices. > + * > + * Provides synchronous device creation: waits for probe completion and > + * returns the probe success or error status to the device creator. > + * > + * Copyright (C) 2021 Bartosz Golaszewski <brgl@bgdev.pl> > + * Copyright (C) 2025 Koichiro Den <koichiro.den@canonical.com> > + */ > + > +#include <linux/device.h> > +#include <linux/slab.h> > + > +#include "dev-sync-probe.h" > + > +static int dev_sync_probe_notifier_call(struct notifier_block *nb, > + unsigned long action, void *data) > +{ > + struct dev_sync_probe_data *pdata; > + struct device *dev = data; > + > + pdata = container_of(nb, struct dev_sync_probe_data, bus_notifier); > + if (!device_match_name(dev, pdata->name)) > + return NOTIFY_DONE; > + > + switch (action) { > + case BUS_NOTIFY_BOUND_DRIVER: > + pdata->driver_bound = true; > + break; > + case BUS_NOTIFY_DRIVER_NOT_BOUND: > + pdata->driver_bound = false; > + break; > + default: > + return NOTIFY_DONE; > + } > + > + complete(&pdata->probe_completion); > + return NOTIFY_OK; > +} > + > +void dev_sync_probe_init(struct dev_sync_probe_data *data) > +{ > + memset(data, 0, sizeof(*data)); > + init_completion(&data->probe_completion); > + data->bus_notifier.notifier_call = dev_sync_probe_notifier_call; > +} > +EXPORT_SYMBOL_GPL(dev_sync_probe_init); > + > +int dev_sync_probe_register(struct dev_sync_probe_data *data, > + struct platform_device_info *pdevinfo) > +{ > + struct platform_device *pdev; > + char *name; > + > + name = kasprintf(GFP_KERNEL, "%s.%d", pdevinfo->name, pdevinfo->id); > + if (!name) > + return -ENOMEM; > + > + data->driver_bound = false; > + data->name = name; > + reinit_completion(&data->probe_completion); > + bus_register_notifier(&platform_bus_type, &data->bus_notifier); > + > + pdev = platform_device_register_full(pdevinfo); > + if (IS_ERR(pdev)) { > + bus_unregister_notifier(&platform_bus_type, &data->bus_notifier); > + kfree(data->name); > + return PTR_ERR(pdev); > + } > + > + wait_for_completion(&data->probe_completion); > + bus_unregister_notifier(&platform_bus_type, &data->bus_notifier); > + > + if (!data->driver_bound) { > + platform_device_unregister(pdev); > + kfree(data->name); > + return -ENXIO; > + } > + > + data->pdev = pdev; > + return 0; > +} > +EXPORT_SYMBOL_GPL(dev_sync_probe_register); > + > +void dev_sync_probe_unregister(struct dev_sync_probe_data *data) > +{ > + platform_device_unregister(data->pdev); > + kfree(data->name); > + data->pdev = NULL; > +} > +EXPORT_SYMBOL_GPL(dev_sync_probe_unregister); > + > +MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>"); > +MODULE_AUTHOR("Koichiro Den <koichiro.den@canonical.com>"); > +MODULE_DESCRIPTION("Utilities for synchronous fake device creation"); > +MODULE_LICENSE("GPL"); > diff --git a/drivers/gpio/dev-sync-probe.h b/drivers/gpio/dev-sync-probe.h > new file mode 100644 > index 000000000000..4b3d52b70519 > --- /dev/null > +++ b/drivers/gpio/dev-sync-probe.h > @@ -0,0 +1,25 @@ > +/* SPDX-License-Identifier: GPL-2.0 */ > + > +#ifndef DEV_SYNC_PROBE_H > +#define DEV_SYNC_PROBE_H > + > +#include <linux/completion.h> > +#include <linux/notifier.h> > +#include <linux/platform_device.h> > + > +struct dev_sync_probe_data { > + struct platform_device *pdev; > + const char *name; > + > + /* Synchronize with probe */ > + struct notifier_block bus_notifier; > + struct completion probe_completion; > + bool driver_bound; > +}; > + > +void dev_sync_probe_init(struct dev_sync_probe_data *data); > +int dev_sync_probe_register(struct dev_sync_probe_data *data, > + struct platform_device_info *pdevinfo); > +void dev_sync_probe_unregister(struct dev_sync_probe_data *data); > + > +#endif /* DEV_SYNC_PROBE_H */ > -- > 2.45.2 >
diff --git a/drivers/gpio/Kconfig b/drivers/gpio/Kconfig index 2be612f9ce55..21ac40bde9c4 100644 --- a/drivers/gpio/Kconfig +++ b/drivers/gpio/Kconfig @@ -1935,3 +1935,6 @@ config GPIO_VIRTUSER endmenu endif + +config DEV_SYNC_PROBE + tristate diff --git a/drivers/gpio/Makefile b/drivers/gpio/Makefile index e6b6355c66d4..a18cf557eca6 100644 --- a/drivers/gpio/Makefile +++ b/drivers/gpio/Makefile @@ -19,6 +19,9 @@ obj-$(CONFIG_GPIO_GENERIC) += gpio-generic.o # directly supported by gpio-generic gpio-generic-$(CONFIG_GPIO_GENERIC) += gpio-mmio.o +# Utilities for drivers that need synchronous fake device creation +obj-$(CONFIG_DEV_SYNC_PROBE) += dev-sync-probe.o + obj-$(CONFIG_GPIO_104_DIO_48E) += gpio-104-dio-48e.o obj-$(CONFIG_GPIO_104_IDI_48) += gpio-104-idi-48.o obj-$(CONFIG_GPIO_104_IDIO_16) += gpio-104-idio-16.o diff --git a/drivers/gpio/dev-sync-probe.c b/drivers/gpio/dev-sync-probe.c new file mode 100644 index 000000000000..9ea733b863b2 --- /dev/null +++ b/drivers/gpio/dev-sync-probe.c @@ -0,0 +1,97 @@ +// SPDX-License-Identifier: GPL-2.0-or-later +/* + * Common code for drivers creating fake platform devices. + * + * Provides synchronous device creation: waits for probe completion and + * returns the probe success or error status to the device creator. + * + * Copyright (C) 2021 Bartosz Golaszewski <brgl@bgdev.pl> + * Copyright (C) 2025 Koichiro Den <koichiro.den@canonical.com> + */ + +#include <linux/device.h> +#include <linux/slab.h> + +#include "dev-sync-probe.h" + +static int dev_sync_probe_notifier_call(struct notifier_block *nb, + unsigned long action, void *data) +{ + struct dev_sync_probe_data *pdata; + struct device *dev = data; + + pdata = container_of(nb, struct dev_sync_probe_data, bus_notifier); + if (!device_match_name(dev, pdata->name)) + return NOTIFY_DONE; + + switch (action) { + case BUS_NOTIFY_BOUND_DRIVER: + pdata->driver_bound = true; + break; + case BUS_NOTIFY_DRIVER_NOT_BOUND: + pdata->driver_bound = false; + break; + default: + return NOTIFY_DONE; + } + + complete(&pdata->probe_completion); + return NOTIFY_OK; +} + +void dev_sync_probe_init(struct dev_sync_probe_data *data) +{ + memset(data, 0, sizeof(*data)); + init_completion(&data->probe_completion); + data->bus_notifier.notifier_call = dev_sync_probe_notifier_call; +} +EXPORT_SYMBOL_GPL(dev_sync_probe_init); + +int dev_sync_probe_register(struct dev_sync_probe_data *data, + struct platform_device_info *pdevinfo) +{ + struct platform_device *pdev; + char *name; + + name = kasprintf(GFP_KERNEL, "%s.%d", pdevinfo->name, pdevinfo->id); + if (!name) + return -ENOMEM; + + data->driver_bound = false; + data->name = name; + reinit_completion(&data->probe_completion); + bus_register_notifier(&platform_bus_type, &data->bus_notifier); + + pdev = platform_device_register_full(pdevinfo); + if (IS_ERR(pdev)) { + bus_unregister_notifier(&platform_bus_type, &data->bus_notifier); + kfree(data->name); + return PTR_ERR(pdev); + } + + wait_for_completion(&data->probe_completion); + bus_unregister_notifier(&platform_bus_type, &data->bus_notifier); + + if (!data->driver_bound) { + platform_device_unregister(pdev); + kfree(data->name); + return -ENXIO; + } + + data->pdev = pdev; + return 0; +} +EXPORT_SYMBOL_GPL(dev_sync_probe_register); + +void dev_sync_probe_unregister(struct dev_sync_probe_data *data) +{ + platform_device_unregister(data->pdev); + kfree(data->name); + data->pdev = NULL; +} +EXPORT_SYMBOL_GPL(dev_sync_probe_unregister); + +MODULE_AUTHOR("Bartosz Golaszewski <brgl@bgdev.pl>"); +MODULE_AUTHOR("Koichiro Den <koichiro.den@canonical.com>"); +MODULE_DESCRIPTION("Utilities for synchronous fake device creation"); +MODULE_LICENSE("GPL"); diff --git a/drivers/gpio/dev-sync-probe.h b/drivers/gpio/dev-sync-probe.h new file mode 100644 index 000000000000..4b3d52b70519 --- /dev/null +++ b/drivers/gpio/dev-sync-probe.h @@ -0,0 +1,25 @@ +/* SPDX-License-Identifier: GPL-2.0 */ + +#ifndef DEV_SYNC_PROBE_H +#define DEV_SYNC_PROBE_H + +#include <linux/completion.h> +#include <linux/notifier.h> +#include <linux/platform_device.h> + +struct dev_sync_probe_data { + struct platform_device *pdev; + const char *name; + + /* Synchronize with probe */ + struct notifier_block bus_notifier; + struct completion probe_completion; + bool driver_bound; +}; + +void dev_sync_probe_init(struct dev_sync_probe_data *data); +int dev_sync_probe_register(struct dev_sync_probe_data *data, + struct platform_device_info *pdevinfo); +void dev_sync_probe_unregister(struct dev_sync_probe_data *data); + +#endif /* DEV_SYNC_PROBE_H */