From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751929AbdK3If5 (ORCPT ); Thu, 30 Nov 2017 03:35:57 -0500 Received: from mail-wm0-f68.google.com ([74.125.82.68]:36000 "EHLO mail-wm0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750849AbdK3If4 (ORCPT ); Thu, 30 Nov 2017 03:35:56 -0500 X-Google-Smtp-Source: AGs4zMYL6gJf3jeu8qy/GqtrM2MI1AiMjRNaSir404u82ZRq2orGaFXVjhXQjxVZZByhhTHFXGGqYQ== Date: Thu, 30 Nov 2017 08:35:52 +0000 From: Lee Jones To: Baolin Wang Cc: arnd@arndb.de, robh+dt@kernel.org, mark.rutland@arm.com, broonie@kernel.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org Subject: Re: [PATCH v4] mfd: syscon: Add hardware spinlock support Message-ID: <20171130083552.ynti3n3njzvps555@dell> References: <2344ec4123c8b0985e54e03a0fa1bfe8d5e68235.1512009343.git.baolin.wang@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <2344ec4123c8b0985e54e03a0fa1bfe8d5e68235.1512009343.git.baolin.wang@linaro.org> User-Agent: NeoMutt/20170113 (1.7.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, 30 Nov 2017, Baolin Wang wrote: > Some system control registers need hardware spinlock to synchronize > between the multiple subsystems, so we should add hardware spinlock > support for syscon. > > Signed-off-by: Baolin Wang > Acked-by: Rob Herring > --- > Changes since v3: > - Add error handling for of_hwspin_lock_get_id() > > Changes since v2: > - Add acked tag from Rob. > > Changes since v1: > - Remove timeout configuration. > - Modify the binding file to add hwlocks. > --- > Documentation/devicetree/bindings/mfd/syscon.txt | 1 + > drivers/mfd/syscon.c | 21 +++++++++++++++++++++ > 2 files changed, 22 insertions(+) > > diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt > index 8b92d45..f464cc8 100644 > --- a/Documentation/devicetree/bindings/mfd/syscon.txt > +++ b/Documentation/devicetree/bindings/mfd/syscon.txt > @@ -16,6 +16,7 @@ Required properties: > Optional property: > - reg-io-width: the size (in bytes) of the IO accesses that should be > performed on the device. > +- hwlocks: reference to a phandle of a hardware spinlock provider node. Example? Perhaps even include the hwlock node (I'm not sure what that would look like). > Examples: > gpr: iomuxc-gpr@20e0000 { > diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c > index b93fe4c..caf6a25 100644 > --- a/drivers/mfd/syscon.c > +++ b/drivers/mfd/syscon.c > @@ -13,6 +13,7 @@ > */ > > #include > +#include > #include > #include > #include > @@ -87,6 +88,26 @@ static struct syscon *of_syscon_register(struct device_node *np) > if (ret) > reg_io_width = 4; > > + ret = of_hwspin_lock_get_id(np, 0); > + if (ret > 0) { > + syscon_config.hwlock_id = ret; > + syscon_config.hwlock_mode = HWLOCK_IRQSTATE; > + } else { > + switch (ret) { > + case -ENOENT: > + /* ignore missing hwlock, it's optional */ Is your shift key broken? ;) Please use proper grammar. Sentences start with capital letters. > + break; > + case 0: > + ret = -EINVAL; > + /* fall-through */ > + default: > + pr_err("Failed to retrieve valid hwlock: %d\n", ret); > + /* fall-through */ > + case -EPROBE_DEFER: > + goto err_regmap; > + } > + } > + > syscon_config.reg_stride = reg_io_width; > syscon_config.val_bits = reg_io_width * 8; > syscon_config.max_register = resource_size(&res) - reg_io_width; -- Lee Jones Linaro STMicroelectronics Landing Team Lead Linaro.org │ Open source software for ARM SoCs Follow Linaro: Facebook | Twitter | Blog