Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751809AbdLYGiG (ORCPT ); Mon, 25 Dec 2017 01:38:06 -0500 Received: from mail-pg0-f66.google.com ([74.125.83.66]:37024 "EHLO mail-pg0-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750981AbdLYGh5 (ORCPT ); Mon, 25 Dec 2017 01:37:57 -0500 X-Google-Smtp-Source: ACJfBovTEUR7rSY5IgtPHK3lFIelUhqOMxZXpnYkSWBYPtjp3a0bVsRRJDEew5JDeajl+t2tdB9LfA== From: Baolin Wang To: lee.jones@linaro.org, arnd@arndb.de, robh+dt@kernel.org, mark.rutland@arm.com, broonie@kernel.org Cc: linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, baolin.wang@linaro.org Subject: [PATCH v7 2/2] mfd: syscon: Add hardware spinlock support Date: Mon, 25 Dec 2017 14:37:10 +0800 Message-Id: X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <29fa88f883dae4c1f8a3acb2656cbd7c5a539d40.1514180039.git.baolin.wang@linaro.org> References: <29fa88f883dae4c1f8a3acb2656cbd7c5a539d40.1514180039.git.baolin.wang@linaro.org> In-Reply-To: <29fa88f883dae4c1f8a3acb2656cbd7c5a539d40.1514180039.git.baolin.wang@linaro.org> References: <29fa88f883dae4c1f8a3acb2656cbd7c5a539d40.1514180039.git.baolin.wang@linaro.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2663 Lines: 92 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 v6: - Treat hwlock id 0 as valid for regmap. Changes since v5: - Fix the case that hwspinlock is not enabled. Changes since v4: - Add one exapmle to show how to add hwlock. - Fix the coding style issue. 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 | 8 ++++++++ drivers/mfd/syscon.c | 19 +++++++++++++++++++ 2 files changed, 27 insertions(+) diff --git a/Documentation/devicetree/bindings/mfd/syscon.txt b/Documentation/devicetree/bindings/mfd/syscon.txt index 8b92d45..25d9e9c 100644 --- a/Documentation/devicetree/bindings/mfd/syscon.txt +++ b/Documentation/devicetree/bindings/mfd/syscon.txt @@ -16,9 +16,17 @@ 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. Examples: gpr: iomuxc-gpr@20e0000 { compatible = "fsl,imx6q-iomuxc-gpr", "syscon"; reg = <0x020e0000 0x38>; + hwlocks = <&hwlock1 1>; +}; + +hwlock1: hwspinlock@40500000 { + ... + reg = <0x40500000 0x1000>; + #hwlock-cells = <1>; }; diff --git a/drivers/mfd/syscon.c b/drivers/mfd/syscon.c index b93fe4c..7eaa40b 100644 --- a/drivers/mfd/syscon.c +++ b/drivers/mfd/syscon.c @@ -13,6 +13,7 @@ */ #include +#include #include #include #include @@ -87,6 +88,24 @@ 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 || (IS_ENABLED(CONFIG_HWSPINLOCK) && ret == 0)) { + syscon_config.use_hwlock = true; + syscon_config.hwlock_id = ret; + syscon_config.hwlock_mode = HWLOCK_IRQSTATE; + } else if (ret < 0) { + switch (ret) { + case -ENOENT: + /* Ignore missing hwlock, it's optional. */ + break; + 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; -- 1.7.9.5