From dbe2256ddd8e8420c254c79f4045c41cb5f4bd6b Mon Sep 17 00:00:00 2001 From: Thierry Reding Date: Fri, 25 Sep 2015 17:29:04 +0200 Subject: driver-core: platform: Provide helpers for multi-driver modules Some modules register several sub-drivers. Provide a helper that makes it easy to register and unregister a list of sub-drivers, as well as unwind properly on error. Signed-off-by: Thierry Reding Signed-off-by: Greg Kroah-Hartman --- drivers/base/platform.c | 61 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 61 insertions(+) (limited to 'drivers/base/platform.c') diff --git a/drivers/base/platform.c b/drivers/base/platform.c index 07cec9ba5e70..1dd6d3bf1098 100644 --- a/drivers/base/platform.c +++ b/drivers/base/platform.c @@ -710,6 +710,67 @@ err_out: } EXPORT_SYMBOL_GPL(__platform_create_bundle); +/** + * __platform_register_drivers - register an array of platform drivers + * @drivers: an array of drivers to register + * @count: the number of drivers to register + * @owner: module owning the drivers + * + * Registers platform drivers specified by an array. On failure to register a + * driver, all previously registered drivers will be unregistered. Callers of + * this API should use platform_unregister_drivers() to unregister drivers in + * the reverse order. + * + * Returns: 0 on success or a negative error code on failure. + */ +int __platform_register_drivers(struct platform_driver * const *drivers, + unsigned int count, struct module *owner) +{ + unsigned int i; + int err; + + for (i = 0; i < count; i++) { + pr_debug("registering platform driver %ps\n", drivers[i]); + + err = __platform_driver_register(drivers[i], owner); + if (err < 0) { + pr_err("failed to register platform driver %ps: %d\n", + drivers[i], err); + goto error; + } + } + + return 0; + +error: + while (i--) { + pr_debug("unregistering platform driver %ps\n", drivers[i]); + platform_driver_unregister(drivers[i]); + } + + return err; +} +EXPORT_SYMBOL_GPL(__platform_register_drivers); + +/** + * platform_unregister_drivers - unregister an array of platform drivers + * @drivers: an array of drivers to unregister + * @count: the number of drivers to unregister + * + * Unegisters platform drivers specified by an array. This is typically used + * to complement an earlier call to platform_register_drivers(). Drivers are + * unregistered in the reverse order in which they were registered. + */ +void platform_unregister_drivers(struct platform_driver * const *drivers, + unsigned int count) +{ + while (count--) { + pr_debug("unregistering platform driver %ps\n", drivers[count]); + platform_driver_unregister(drivers[count]); + } +} +EXPORT_SYMBOL_GPL(platform_unregister_drivers); + /* modalias support enables more hands-off userspace setup: * (a) environment variable lets new-style hotplug events work once system is * fully running: "modprobe $MODALIAS" -- cgit v1.2.3