diff options
Diffstat (limited to 'drivers/of/dynamic.c')
| -rw-r--r-- | drivers/of/dynamic.c | 96 |
1 files changed, 96 insertions, 0 deletions
diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index 661ad2f5c00c..6659c39ab3aa 100644 --- a/drivers/of/dynamic.c +++ b/drivers/of/dynamic.c @@ -85,6 +85,102 @@ int of_reconfig_notify(unsigned long action, void *p) return notifier_to_errno(rc); } +/* + * of_reconfig_get_state_change() - Returns new state of device + * @action - action of the of notifier + * @arg - argument of the of notifier + * + * Returns the new state of a device based on the notifier used. + * Returns 0 on device going from enabled to disabled, 1 on device + * going from disabled to enabled and -1 on no change. + */ +int of_reconfig_get_state_change(unsigned long action, void *arg) +{ + struct device_node *dn; + struct property *prop, *old_prop; + struct of_prop_reconfig *pr; + int is_status, status_state, old_status_state, prev_state, new_state; + + /* figure out if a device should be created or destroyed */ + dn = NULL; + prop = old_prop = NULL; + switch (action) { + case OF_RECONFIG_ATTACH_NODE: + case OF_RECONFIG_DETACH_NODE: + dn = arg; + prop = of_find_property(dn, "status", NULL); + break; + case OF_RECONFIG_ADD_PROPERTY: + case OF_RECONFIG_REMOVE_PROPERTY: + pr = arg; + dn = pr->dn; + prop = pr->prop; + break; + case OF_RECONFIG_UPDATE_PROPERTY: + pr = arg; + dn = pr->dn; + prop = pr->prop; + old_prop = pr->old_prop; + break; + default: + return OF_RECONFIG_NO_CHANGE; + } + + is_status = 0; + status_state = -1; + old_status_state = -1; + prev_state = -1; + new_state = -1; + + if (prop && !strcmp(prop->name, "status")) { + is_status = 1; + status_state = !strcmp(prop->value, "okay") || + !strcmp(prop->value, "ok"); + if (old_prop) + old_status_state = !strcmp(old_prop->value, "okay") || + !strcmp(old_prop->value, "ok"); + } + + switch (action) { + case OF_RECONFIG_ATTACH_NODE: + prev_state = 0; + /* -1 & 0 status either missing or okay */ + new_state = status_state != 0; + break; + case OF_RECONFIG_DETACH_NODE: + /* -1 & 0 status either missing or okay */ + prev_state = status_state != 0; + new_state = 0; + break; + case OF_RECONFIG_ADD_PROPERTY: + if (is_status) { + /* no status property -> enabled (legacy) */ + prev_state = 1; + new_state = status_state; + } + break; + case OF_RECONFIG_REMOVE_PROPERTY: + if (is_status) { + prev_state = status_state; + /* no status property -> enabled (legacy) */ + new_state = 1; + } + break; + case OF_RECONFIG_UPDATE_PROPERTY: + if (is_status) { + prev_state = old_status_state != 0; + new_state = status_state != 0; + } + break; + } + + if (prev_state == new_state) + return OF_RECONFIG_NO_CHANGE; + + return new_state ? OF_RECONFIG_CHANGE_ADD : OF_RECONFIG_CHANGE_REMOVE; +} +EXPORT_SYMBOL_GPL(of_reconfig_get_state_change); + int of_property_notify(int action, struct device_node *np, struct property *prop, struct property *oldprop) { |