Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753602AbaHACpH (ORCPT ); Thu, 31 Jul 2014 22:45:07 -0400 Received: from exprod5og118.obsmtp.com ([64.18.0.160]:39853 "HELO exprod5og118.obsmtp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751774AbaHACpC (ORCPT ); Thu, 31 Jul 2014 22:45:02 -0400 From: Feng Kan To: linux@roeck-us.net, dbaryshkov@gmail.com, catalin.marinas@arm.com, dwmw2@infradead.org, arnd@arndb.de, devicetree@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, patches@apm.com Cc: Feng Kan Subject: [PATCH V9 1/6] power: reset: Add generic SYSCON register mapped reset Date: Thu, 31 Jul 2014 19:45:52 -0700 Message-Id: <1406861157-29169-2-git-send-email-fkan@apm.com> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1406861157-29169-1-git-send-email-fkan@apm.com> References: <1406861157-29169-1-git-send-email-fkan@apm.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Add a generic SYSCON register mapped reset mechanism. Signed-off-by: Feng Kan --- drivers/power/reset/Kconfig | 5 ++ drivers/power/reset/Makefile | 1 + drivers/power/reset/syscon-reboot.c | 98 +++++++++++++++++++++++++++++++++++++ 3 files changed, 104 insertions(+) create mode 100644 drivers/power/reset/syscon-reboot.c diff --git a/drivers/power/reset/Kconfig b/drivers/power/reset/Kconfig index bdcf517..fd5f9e5 100644 --- a/drivers/power/reset/Kconfig +++ b/drivers/power/reset/Kconfig @@ -80,3 +80,8 @@ config POWER_RESET_KEYSTONE help Reboot support for the KEYSTONE SoCs. +config POWER_RESET_SYSCON + bool "Generic SYSCON regmap reset driver" + depends on POWER_RESET && MFD_SYSCON && OF + help + Reboot support for generic SYSCON mapped register reset. diff --git a/drivers/power/reset/Makefile b/drivers/power/reset/Makefile index dde2e8b..b1b5ab3 100644 --- a/drivers/power/reset/Makefile +++ b/drivers/power/reset/Makefile @@ -8,3 +8,4 @@ obj-$(CONFIG_POWER_RESET_SUN6I) += sun6i-reboot.o obj-$(CONFIG_POWER_RESET_VEXPRESS) += vexpress-poweroff.o obj-$(CONFIG_POWER_RESET_XGENE) += xgene-reboot.o obj-$(CONFIG_POWER_RESET_KEYSTONE) += keystone-reset.o +obj-$(CONFIG_POWER_RESET_SYSCON) += syscon-reboot.o diff --git a/drivers/power/reset/syscon-reboot.c b/drivers/power/reset/syscon-reboot.c new file mode 100644 index 0000000..75d6eae --- /dev/null +++ b/drivers/power/reset/syscon-reboot.c @@ -0,0 +1,98 @@ +/* + * Generic Syscon Reboot Driver + * + * Copyright (c) 2013, Applied Micro Circuits Corporation + * Author: Feng Kan + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + */ +#include +#include +#include +#include +#include +#include +#include +#include + +struct syscon_reboot_context { + struct regmap *map; + u32 offset; + u32 mask; + struct notifier_block restart_handler; +}; + +static struct syscon_reboot_context *syscon_reboot_ctx; + +static int syscon_restart_handle(struct notifier_block *this, + unsigned long mode, void *cmd) +{ + struct syscon_reboot_context *ctx = syscon_reboot_ctx; + unsigned long timeout; + + /* Issue the reboot */ + if (ctx->map) + regmap_write(ctx->map, ctx->offset, ctx->mask); + + timeout = jiffies + HZ; + while (time_before(jiffies, timeout)) + cpu_relax(); + + pr_emerg("Unable to restart system\n"); + return NOTIFY_DONE; +} + +static int syscon_reboot_probe(struct platform_device *pdev) +{ + struct syscon_reboot_context *ctx; + struct device *dev = &pdev->dev; + int err; + + ctx = devm_kzalloc(&pdev->dev, sizeof(*ctx), GFP_KERNEL); + if (!ctx) { + dev_err(&pdev->dev, "out of memory for context\n"); + return -ENOMEM; + } + + ctx->map = syscon_regmap_lookup_by_phandle(dev->of_node, "regmap"); + if (IS_ERR(ctx->map)) + return PTR_ERR(ctx->map); + + if (of_property_read_u32(pdev->dev.of_node, "offset", &ctx->offset)) + return -EINVAL; + + if (of_property_read_u32(pdev->dev.of_node, "mask", &ctx->mask)) + return -EINVAL; + + ctx->restart_handler.notifier_call = syscon_restart_handle; + ctx->restart_handler.priority = 128; + err = register_restart_handler(&ctx->restart_handler); + if (err) + dev_err(dev, "can't register restart notifier (err=%d)\n", err); + + syscon_reboot_ctx = ctx; + + return 0; +} + +static struct of_device_id syscon_reboot_of_match[] = { + { .compatible = "syscon-reboot" }, + {} +}; + +static struct platform_driver syscon_reboot_driver = { + .probe = syscon_reboot_probe, + .driver = { + .name = "syscon-reboot", + .of_match_table = syscon_reboot_of_match, + }, +}; +module_platform_driver(syscon_reboot_driver); -- 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/