From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756835AbaEEVoy (ORCPT ); Mon, 5 May 2014 17:44:54 -0400 Received: from bear.ext.ti.com ([192.94.94.41]:60905 "EHLO bear.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755936AbaEEVox (ORCPT ); Mon, 5 May 2014 17:44:53 -0400 Message-ID: <53680639.1080405@ti.com> Date: Mon, 5 May 2014 16:44:25 -0500 From: Suman Anna User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.5.0 MIME-Version: 1.0 To: Ohad Ben-Cohen , Mark Rutland , Kumar Gala , Rob Herring CC: Tony Lindgren , Josh Cartwright , Bjorn Andersson , , , , Subject: Re: [PATCHv5 RFC 12/15] hwspinlock/core: add OF helper to parse reserved locks References: <1398904476-26200-1-git-send-email-s-anna@ti.com> <1398904476-26200-13-git-send-email-s-anna@ti.com> In-Reply-To: <1398904476-26200-13-git-send-email-s-anna@ti.com> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Rob, On 04/30/2014 07:34 PM, Suman Anna wrote: > The property 'hwlock-reserved-locks' will be used to represent > the number of locks to be reserved for clients that would need > to request/operate on specific locks. A new OF helper function, > of_hwspin_lock_get_num_reserved_locks(), is added to minimize > duplication in different platform implementations. > > The function will return a value of 0 if the property is not > defined, so as to support a default behavior of marking all > locks as unused and open for anonymous allocations. > > Signed-off-by: Suman Anna > --- > .../devicetree/bindings/hwlock/hwlock.txt | 3 +++ > drivers/hwspinlock/hwspinlock_core.c | 25 ++++++++++++++++++++++ > include/linux/hwspinlock.h | 1 + > 3 files changed, 29 insertions(+) > > diff --git a/Documentation/devicetree/bindings/hwlock/hwlock.txt b/Documentation/devicetree/bindings/hwlock/hwlock.txt > index d538a9b..88d16d2 100644 > --- a/Documentation/devicetree/bindings/hwlock/hwlock.txt > +++ b/Documentation/devicetree/bindings/hwlock/hwlock.txt > @@ -18,6 +18,9 @@ Common properties: > property is needed on hwlock devices, where the number > of supported locks within a hwlock device cannot be > read from a register. > +- hwlock-reserved-locks: Number of locks to reserve for clients requiring > + specific locks. This value cannot exceed the value of > + hwlock-num-locks. Any suggestions here on the approach? This property falls into a gray area as well, as the current approach is somewhat limiting (it doesn't support sparse reserved locks, and expects them at the beginning of the lock range). regards Suman > - hwlock-base-id: An unique base Id for the locks for a particular hwlock > device. This property is mandatory ONLY if a SoC has > several hwlock devices. > diff --git a/drivers/hwspinlock/hwspinlock_core.c b/drivers/hwspinlock/hwspinlock_core.c > index e05cea8..e74b55b 100644 > --- a/drivers/hwspinlock/hwspinlock_core.c > +++ b/drivers/hwspinlock/hwspinlock_core.c > @@ -286,6 +286,31 @@ int of_hwspin_lock_get_base_id(struct device_node *dn) > EXPORT_SYMBOL_GPL(of_hwspin_lock_get_base_id); > > /** > + * of_hwspin_lock_get_num_reserved_locks() - retrieve number of reserved locks > + * @dn: device node pointer > + * > + * This is an OF helper function that can be called by the underlying platform > + * specific implementations, to retrieve the number of locks to reserve from > + * the hwspinlock device instance's base id. The hwlock-reserved-locks DT > + * property needs to be defined for requesting any DT-based locks. > + * > + * Returns a positive number of locks on success, a default value of 0 if the > + * property is missing or an appropriate error code as returned by the OF layer > + */ > +int of_hwspin_lock_get_num_reserved_locks(struct device_node *dn) > +{ > + unsigned int val = 0; > + int ret; > + > + ret = of_property_read_u32(dn, "hwlock-reserved-locks", &val); > + if (!ret || ret == -EINVAL) > + ret = val; > + > + return ret; > +} > +EXPORT_SYMBOL_GPL(of_hwspin_lock_get_num_reserved_locks); > + > +/** > * of_hwspin_lock_get_num_locks() - OF helper to retrieve number of locks > * @dn: device node pointer > * > diff --git a/include/linux/hwspinlock.h b/include/linux/hwspinlock.h > index d120035..d18431f 100644 > --- a/include/linux/hwspinlock.h > +++ b/include/linux/hwspinlock.h > @@ -69,6 +69,7 @@ int of_hwspin_lock_simple_xlate(struct hwspinlock_device *bank, > const struct of_phandle_args *hwlock_spec); > int of_hwspin_lock_get_base_id(struct device_node *dn); > int of_hwspin_lock_get_num_locks(struct device_node *dn); > +int of_hwspin_lock_get_num_reserved_locks(struct device_node *dn); > int hwspin_lock_register(struct hwspinlock_device *bank, struct device *dev, > const struct hwspinlock_ops *ops, int base_id, int num_locks, > int num_reserved_locks); >