Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932568AbaKUBhx (ORCPT ); Thu, 20 Nov 2014 20:37:53 -0500 Received: from mail-wi0-f178.google.com ([209.85.212.178]:35077 "EHLO mail-wi0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756947AbaKUBfb (ORCPT ); Thu, 20 Nov 2014 20:35:31 -0500 From: Grant Likely To: devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, Pantelis Antoniou Cc: Rob Herring , Grant Likely Subject: [PATCH 4/8] of: Add of_reconfig_get_state_change() of notifier helper. Date: Fri, 21 Nov 2014 01:35:11 +0000 Message-Id: <1416533715-9758-5-git-send-email-grant.likely@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1416533715-9758-1-git-send-email-grant.likely@linaro.org> References: <1416533715-9758-1-git-send-email-grant.likely@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Pantelis Antoniou Introduce of_reconfig_get_state_change() which allows an of notifier to query about device state changes. Signed-off-by: Pantelis Antoniou Signed-off-by: Grant Likely --- drivers/of/dynamic.c | 96 ++++++++++++++++++++++++++++++++++++++++++++++++++++ include/linux/of.h | 1 + 2 files changed, 97 insertions(+) diff --git a/drivers/of/dynamic.c b/drivers/of/dynamic.c index 7c095bffef3a..7634c2f69d4a 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 -1; /* don't care */ + } + + 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 -1; + + return new_state; +} +EXPORT_SYMBOL_GPL(of_reconfig_get_state_change); + int of_property_notify(int action, struct device_node *np, struct property *prop, struct property *oldprop) { diff --git a/include/linux/of.h b/include/linux/of.h index 27635c89d8c2..96f678515d8f 100644 --- a/include/linux/of.h +++ b/include/linux/of.h @@ -327,6 +327,7 @@ struct of_prop_reconfig { extern int of_reconfig_notifier_register(struct notifier_block *); extern int of_reconfig_notifier_unregister(struct notifier_block *); extern int of_reconfig_notify(unsigned long, void *); +extern int of_reconfig_get_state_change(unsigned long action, void *arg); extern int of_attach_node(struct device_node *); extern int of_detach_node(struct device_node *); -- 1.9.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/