diff options
author | Michał Mirosław <mirq-linux@rere.qmqm.pl> | 2019-08-10 10:42:52 +0200 |
---|---|---|
committer | Felipe Balbi <felipe.balbi@linux.intel.com> | 2019-10-22 10:27:15 +0300 |
commit | bd25a14edb75038f6a177ac566ba2e6d7a2439be (patch) | |
tree | 079b362a7f5a7a5120025ce39562febc6eae1c60 /drivers/usb/gadget | |
parent | d7cb8fb7aa7dc47d1b751c17c15672068667053c (diff) | |
download | linux-bd25a14edb75038f6a177ac566ba2e6d7a2439be.tar.gz linux-bd25a14edb75038f6a177ac566ba2e6d7a2439be.tar.bz2 linux-bd25a14edb75038f6a177ac566ba2e6d7a2439be.zip |
usb: gadget: legacy/serial: allow dynamic removal
Legacy serial USB gadget is still useful as an early console,
before userspace is up. Later it could be replaced with proper
configfs-configured composite gadget - that use case is enabled
by this patch.
Signed-off-by: Michał Mirosław <mirq-linux@rere.qmqm.pl>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Diffstat (limited to 'drivers/usb/gadget')
-rw-r--r-- | drivers/usb/gadget/legacy/serial.c | 49 |
1 files changed, 48 insertions, 1 deletions
diff --git a/drivers/usb/gadget/legacy/serial.c b/drivers/usb/gadget/legacy/serial.c index de30d7628eef..da44f89f5e73 100644 --- a/drivers/usb/gadget/legacy/serial.c +++ b/drivers/usb/gadget/legacy/serial.c @@ -97,6 +97,36 @@ static unsigned n_ports = 1; module_param(n_ports, uint, 0); MODULE_PARM_DESC(n_ports, "number of ports to create, default=1"); +static bool enable = true; + +static int switch_gserial_enable(bool do_enable); + +static int enable_set(const char *s, const struct kernel_param *kp) +{ + bool do_enable; + int ret; + + if (!s) /* called for no-arg enable == default */ + return 0; + + ret = strtobool(s, &do_enable); + if (ret || enable == do_enable) + return ret; + + ret = switch_gserial_enable(do_enable); + if (!ret) + enable = do_enable; + + return ret; +} + +static const struct kernel_param_ops enable_ops = { + .set = enable_set, + .get = param_get_bool, +}; + +module_param_cb(enable, &enable_ops, &enable, 0644); + /*-------------------------------------------------------------------------*/ static struct usb_configuration serial_config_driver = { @@ -240,6 +270,19 @@ static struct usb_composite_driver gserial_driver = { .unbind = gs_unbind, }; +static int switch_gserial_enable(bool do_enable) +{ + if (!serial_config_driver.label) + /* init() was not called, yet */ + return 0; + + if (do_enable) + return usb_composite_probe(&gserial_driver); + + usb_composite_unregister(&gserial_driver); + return 0; +} + static int __init init(void) { /* We *could* export two configs; that'd be much cleaner... @@ -266,12 +309,16 @@ static int __init init(void) } strings_dev[STRING_DESCRIPTION_IDX].s = serial_config_driver.label; + if (!enable) + return 0; + return usb_composite_probe(&gserial_driver); } module_init(init); static void __exit cleanup(void) { - usb_composite_unregister(&gserial_driver); + if (enable) + usb_composite_unregister(&gserial_driver); } module_exit(cleanup); |