d/freebsd-skq
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Implement bus_rescan for gpiobus(4). This allows on-the-fly reconfiguration

Browse Source 
of gpio devices by using kenv to add hints for a new device and then do
'devctl rescan gpiobus4' to make the new device(s) attach.

It's not particularly easy to detect whether the 'at' hint has been deleted
for a child device that's currently attached, so this doesn't handle that.
But the user can use devctl commands to manually detach an existing device.
This commit is contained in:
ian 2019-12-06 22:32:06 +00:00
parent 86a0bc5fe4
commit 57fa8b904f
1 changed files with 20 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

20
sys/dev/gpio/gpiobus.c
View File

@ -716,6 +716,21 @@ gpiobus_add_child(device_t dev, u_int order, const char *name, int unit)
return (child);
}
static int
gpiobus_rescan(device_t dev)
{
/*
* Re-scan is supposed to remove and add children, but if someone has
* deleted the hints for a child we attached earlier, we have no easy
* way to handle that. So this just attaches new children for whom new
* hints or drivers have arrived since we last tried.
*/
bus_enumerate_hinted_children(dev);
bus_generic_attach(dev);
return (0);
}
static void
gpiobus_hinted_child(device_t bus, const char *dname, int dunit)
{
@ -725,6 +740,10 @@ gpiobus_hinted_child(device_t bus, const char *dname, int dunit)
const char *pins;
int irq, pinmask;
if (device_find_child(bus, dname, dunit) != NULL) {
return;
}
child = BUS_ADD_CHILD(bus, 0, dname, dunit);
devi = GPIOBUS_IVAR(child);
if (resource_int_value(dname, dunit, "pins", &pinmask) == 0) {
@ -1077,6 +1096,7 @@ static device_method_t gpiobus_methods[] = {
DEVMETHOD(bus_deactivate_resource, bus_generic_deactivate_resource),
DEVMETHOD(bus_get_resource_list, gpiobus_get_resource_list),
DEVMETHOD(bus_add_child, gpiobus_add_child),
DEVMETHOD(bus_rescan, gpiobus_rescan),
DEVMETHOD(bus_probe_nomatch, gpiobus_probe_nomatch),
DEVMETHOD(bus_print_child, gpiobus_print_child),
DEVMETHOD(bus_child_pnpinfo_str, gpiobus_child_pnpinfo_str),