From patchwork Tue Mar 24 09:25:37 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lee Jones X-Patchwork-Id: 453775 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from mail-la0-x23f.google.com (mail-la0-x23f.google.com [IPv6:2a00:1450:4010:c03::23f]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id DACF41400A0 for ; Tue, 24 Mar 2015 20:26:01 +1100 (AEDT) Authentication-Results: ozlabs.org; dkim=pass reason="2048-bit key; unprotected key" header.d=googlegroups.com header.i=@googlegroups.com header.b=LrOuOLUu; dkim-adsp=none (unprotected policy); dkim-atps=neutral Received: by labhs14 with SMTP id hs14sf51596206lab.0 for ; Tue, 24 Mar 2015 02:25:59 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlegroups.com; s=20120806; h=mime-version:from:to:cc:subject:date:message-id:in-reply-to :references:x-original-sender:x-original-authentication-results :reply-to:content-type:precedence:mailing-list:list-id:list-post :list-help:list-archive:sender:list-subscribe:list-unsubscribe; bh=msAkzqHAr6Yxc1FistXGuHP2i5Casq6DyiSQFYzKEi0=; b=LrOuOLUuDXRdoQgMR8HFuzEtkjV6DjpOUT94GQxgvqRiT/Kf/lBtTJnZspc0PhHiVw a1Su3YFQz71GPJ7zNAsFBjmVLnB01tZH+9Nu9Fg/UI7mfgSrwKwp2xFboHV7y8rg8k6W 6QUAVt1xEI2WzNo+0AF9f75Nf4dhknc1MCWp4rszw9fhOUQL32SS1dt9HBn94LCzornV BtaIIGr64cuZ/FkZBWr3EkrUjk3qLXGlCUBTfM996sp4irf98cXmJZKAjOt1B3dVF3lS 5FTm9Lrtku2+1ZPi6vhZlW0a/NJ00IRvr2XLGa3Vfjom+27PK52u+Xk+zqD6dyTERDOQ 5aNg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=mime-version:x-gm-message-state:from:to:cc:subject:date:message-id :in-reply-to:references:x-original-sender :x-original-authentication-results:reply-to:content-type:precedence :mailing-list:list-id:list-post:list-help:list-archive:sender :list-subscribe:list-unsubscribe; bh=msAkzqHAr6Yxc1FistXGuHP2i5Casq6DyiSQFYzKEi0=; b=l9a8GKEfaqR4i9UgYmzwz42/nQIdNpDwTMl0VrIQgTCUSAC5zB8/ArDfxaS2wqoXD2 WYOzS92M10Ehz1wkzzXXOgBHzGkxMdnLK/MQjrKUI340w9uJ2WEtjf7oDps9UcK+oMU+ nKw43njDupWRay0u3H34bNwqVO9v/1JdB4ppcp2mW/sWKGc2L84Gl5iN0HPMw78kX92+ 3klQE87Fbz0XcMbx2BHkBnzRpkfCp56kl3GRdAnabJ+CwJYtBQEpM5WpjtG892AXMG/v PR7l0eCrEksYjWtsw0z2Ewj8YxvWrMS5dv+Eb4SCGktw1DRGOlu/4l/40mj09jqn6FKc aHlA== X-Received: by 10.152.116.115 with SMTP id jv19mr32711lab.32.1427189159509; Tue, 24 Mar 2015 02:25:59 -0700 (PDT) MIME-Version: 1.0 X-BeenThere: rtc-linux@googlegroups.com Received: by 10.152.27.74 with SMTP id r10ls22151lag.55.gmail; Tue, 24 Mar 2015 02:25:58 -0700 (PDT) X-Received: by 10.152.8.73 with SMTP id p9mr647557laa.6.1427189158968; Tue, 24 Mar 2015 02:25:58 -0700 (PDT) Received: from mail-wi0-f174.google.com (mail-wi0-f174.google.com. [209.85.212.174]) by gmr-mx.google.com with ESMTPS id bz6si642337wib.3.2015.03.24.02.25.58 for (version=TLSv1.2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 24 Mar 2015 02:25:58 -0700 (PDT) Received-SPF: pass (google.com: domain of lee.jones@linaro.org designates 209.85.212.174 as permitted sender) client-ip=209.85.212.174; Received: by mail-wi0-f174.google.com with SMTP id g7so69314937wib.1 for ; Tue, 24 Mar 2015 02:25:58 -0700 (PDT) X-Gm-Message-State: ALoCoQlpDWJRuSgk1Yb9mf0IVSzrCUl8ft5wO6eLI6pLmBzEEaWoPYfg+jnHmyGW/y2sbTWjcWy+ X-Received: by 10.180.86.201 with SMTP id r9mr26820504wiz.56.1427189158830; Tue, 24 Mar 2015 02:25:58 -0700 (PDT) Received: from localhost.localdomain ([81.134.86.34]) by mx.google.com with ESMTPSA id pm6sm2549370wic.20.2015.03.24.02.25.56 (version=TLSv1.2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 24 Mar 2015 02:25:57 -0700 (PDT) From: Lee Jones To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, rtc-linux@googlegroups.com, wim@iguana.be, linux-watchdog@vger.kernel.org, devicetree@vger.kernel.org, linux@roeck-us.net, david.paris@st.com, a.zummo@towertech.it Cc: lee.jones@linaro.org, kernel@stlinux.com Subject: [rtc-linux] [PATCH v6 6/9] watchdog: st_wdt: Add new driver for ST's LPC Watchdog Date: Tue, 24 Mar 2015 09:25:37 +0000 Message-Id: <1427189140-1935-7-git-send-email-lee.jones@linaro.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1427189140-1935-1-git-send-email-lee.jones@linaro.org> References: <1427189140-1935-1-git-send-email-lee.jones@linaro.org> X-Original-Sender: lee.jones@linaro.org X-Original-Authentication-Results: gmr-mx.google.com; spf=pass (google.com: domain of lee.jones@linaro.org designates 209.85.212.174 as permitted sender) smtp.mail=lee.jones@linaro.org Reply-To: rtc-linux@googlegroups.com Precedence: list Mailing-list: list rtc-linux@googlegroups.com; contact rtc-linux+owners@googlegroups.com List-ID: X-Google-Group-Id: 712029733259 List-Post: , List-Help: , List-Archive: , List-Unsubscribe: , Reviewed-by: Guenter Roeck Signed-off-by: David Paris Signed-off-by: Lee Jones --- drivers/watchdog/Kconfig | 13 ++ drivers/watchdog/Makefile | 1 + drivers/watchdog/st_lpc_wdt.c | 344 ++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 358 insertions(+) create mode 100644 drivers/watchdog/st_lpc_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index 16f2023..8ccd9d9 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -471,6 +471,19 @@ config SIRFSOC_WATCHDOG Support for CSR SiRFprimaII and SiRFatlasVI watchdog. When the watchdog triggers the system will be reset. +config ST_LPC_WATCHDOG + tristate "STMicroelectronics LPC Watchdog" + depends on ARCH_STI + depends on OF + select WATCHDOG_CORE + select MFD_ST_LPC + help + Say Y here to include STMicroelectronics Low Power Controller + (LPC) based Watchdog timer support. + + To compile this driver as a module, choose M here: the + module will be called st_lpc_wdt. + config TEGRA_WATCHDOG tristate "Tegra watchdog" depends on (ARCH_TEGRA || COMPILE_TEST) && HAS_IOMEM diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 5c19294..d98768c 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -59,6 +59,7 @@ obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o obj-$(CONFIG_MOXART_WDT) += moxart_wdt.o obj-$(CONFIG_SIRFSOC_WATCHDOG) += sirfsoc_wdt.o +obj-$(CONFIG_ST_LPC_WATCHDOG) += st_lpc_wdt.o obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o diff --git a/drivers/watchdog/st_lpc_wdt.c b/drivers/watchdog/st_lpc_wdt.c new file mode 100644 index 0000000..f32be15 --- /dev/null +++ b/drivers/watchdog/st_lpc_wdt.c @@ -0,0 +1,344 @@ +/* + * ST's LPC Watchdog + * + * Copyright (C) 2014 STMicroelectronics -- All Rights Reserved + * + * Author: David Paris for STMicroelectronics + * Lee Jones for STMicroelectronics + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public Licence + * as published by the Free Software Foundation; either version + * 2 of the Licence, or (at your option) any later version. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#include + +/* Low Power Alarm */ +#define LPC_LPA_LSB_OFF 0x410 +#define LPC_LPA_START_OFF 0x418 + +/* LPC as WDT */ +#define LPC_WDT_OFF 0x510 + +static struct watchdog_device st_wdog_dev; + +struct st_wdog_syscfg { + unsigned int reset_type_reg; + unsigned int reset_type_mask; + unsigned int enable_reg; + unsigned int enable_mask; +}; + +struct st_wdog { + void __iomem *base; + struct device *dev; + struct regmap *regmap; + struct st_wdog_syscfg *syscfg; + struct clk *clk; + unsigned long clkrate; + bool warm_reset; +}; + +static struct st_wdog_syscfg stid127_syscfg = { + .reset_type_reg = 0x004, + .reset_type_mask = BIT(2), + .enable_reg = 0x000, + .enable_mask = BIT(2), +}; + +static struct st_wdog_syscfg stih415_syscfg = { + .reset_type_reg = 0x0B8, + .reset_type_mask = BIT(6), + .enable_reg = 0x0B4, + .enable_mask = BIT(7), +}; + +static struct st_wdog_syscfg stih416_syscfg = { + .reset_type_reg = 0x88C, + .reset_type_mask = BIT(6), + .enable_reg = 0x888, + .enable_mask = BIT(7), +}; + +static struct st_wdog_syscfg stih407_syscfg = { + .enable_reg = 0x204, + .enable_mask = BIT(19), +}; + +static const struct of_device_id st_wdog_match[] = { + { + .compatible = "st,stih407-lpc", + .data = &stih407_syscfg, + }, + { + .compatible = "st,stih416-lpc", + .data = &stih416_syscfg, + }, + { + .compatible = "st,stih415-lpc", + .data = &stih415_syscfg, + }, + { + .compatible = "st,stid127-lpc", + .data = &stid127_syscfg, + }, + {}, +}; +MODULE_DEVICE_TABLE(of, st_wdog_match); + +static void st_wdog_setup(struct st_wdog *st_wdog, bool enable) +{ + /* Type of watchdog reset - 0: Cold 1: Warm */ + if (st_wdog->syscfg->reset_type_reg) + regmap_update_bits(st_wdog->regmap, + st_wdog->syscfg->reset_type_reg, + st_wdog->syscfg->reset_type_mask, + st_wdog->warm_reset); + + /* Mask/unmask watchdog reset */ + regmap_update_bits(st_wdog->regmap, + st_wdog->syscfg->enable_reg, + st_wdog->syscfg->enable_mask, + enable ? 0 : st_wdog->syscfg->enable_mask); +} + +static void st_wdog_load_timer(struct st_wdog *st_wdog, unsigned int timeout) +{ + unsigned long clkrate = st_wdog->clkrate; + + writel_relaxed(timeout * clkrate, st_wdog->base + LPC_LPA_LSB_OFF); + writel_relaxed(1, st_wdog->base + LPC_LPA_START_OFF); +} + +static int st_wdog_start(struct watchdog_device *wdd) +{ + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); + + writel_relaxed(1, st_wdog->base + LPC_WDT_OFF); + + return 0; +} + +static int st_wdog_stop(struct watchdog_device *wdd) +{ + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); + + writel_relaxed(0, st_wdog->base + LPC_WDT_OFF); + + return 0; +} + +static int st_wdog_set_timeout(struct watchdog_device *wdd, + unsigned int timeout) +{ + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); + + wdd->timeout = timeout; + st_wdog_load_timer(st_wdog, timeout); + + return 0; +} + +static int st_wdog_keepalive(struct watchdog_device *wdd) +{ + struct st_wdog *st_wdog = watchdog_get_drvdata(wdd); + + st_wdog_load_timer(st_wdog, wdd->timeout); + + return 0; +} + +static const struct watchdog_info st_wdog_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE, + .identity = "ST LPC WDT", +}; + +static const struct watchdog_ops st_wdog_ops = { + .owner = THIS_MODULE, + .start = st_wdog_start, + .stop = st_wdog_stop, + .ping = st_wdog_keepalive, + .set_timeout = st_wdog_set_timeout, +}; + +static struct watchdog_device st_wdog_dev = { + .info = &st_wdog_info, + .ops = &st_wdog_ops, +}; + +static int st_wdog_probe(struct platform_device *pdev) +{ + const struct of_device_id *match; + struct device_node *np = pdev->dev.of_node; + struct st_wdog *st_wdog; + struct regmap *regmap; + struct resource *res; + struct clk *clk; + void __iomem *base; + uint32_t mode; + int ret; + + ret = of_property_read_u32(np, "st,lpc-mode", &mode); + if (ret) { + dev_err(&pdev->dev, "An LPC mode must be provided\n"); + return -EINVAL; + } + + /* LPC can either run in RTC or WDT mode */ + if (mode != ST_LPC_MODE_WDT) + return -ENODEV; + + st_wdog = devm_kzalloc(&pdev->dev, sizeof(*st_wdog), GFP_KERNEL); + if (!st_wdog) + return -ENOMEM; + + match = of_match_device(st_wdog_match, &pdev->dev); + if (!match) { + dev_err(&pdev->dev, "Couldn't match device\n"); + return -ENODEV; + } + st_wdog->syscfg = (struct st_wdog_syscfg *)match->data; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(base)) + return PTR_ERR(base); + + regmap = syscon_regmap_lookup_by_phandle(np, "st,syscfg"); + if (IS_ERR(regmap)) { + dev_err(&pdev->dev, "No syscfg phandle specified\n"); + return PTR_ERR(regmap); + } + + clk = devm_clk_get(&pdev->dev, NULL); + if (IS_ERR(clk)) { + dev_err(&pdev->dev, "Unable to request clock\n"); + return PTR_ERR(clk); + } + + st_wdog->dev = &pdev->dev; + st_wdog->base = base; + st_wdog->clk = clk; + st_wdog->regmap = regmap; + st_wdog->warm_reset = of_property_read_bool(np, "st,warm_reset"); + st_wdog->clkrate = clk_get_rate(st_wdog->clk); + + if (!st_wdog->clkrate) { + dev_err(&pdev->dev, "Unable to fetch clock rate\n"); + return -EINVAL; + } + st_wdog_dev.max_timeout = 0xFFFFFFFF / st_wdog->clkrate; + + ret = clk_prepare_enable(clk); + if (ret) { + dev_err(&pdev->dev, "Unable to enable clock\n"); + return ret; + } + + watchdog_set_drvdata(&st_wdog_dev, st_wdog); + watchdog_set_nowayout(&st_wdog_dev, WATCHDOG_NOWAYOUT); + + /* Init Watchdog timeout with value in DT */ + ret = watchdog_init_timeout(&st_wdog_dev, 0, &pdev->dev); + if (ret) { + dev_err(&pdev->dev, "Unable to initialise watchdog timeout\n"); + clk_disable_unprepare(clk); + return ret; + } + + ret = watchdog_register_device(&st_wdog_dev); + if (ret) { + dev_err(&pdev->dev, "Unable to register watchdog\n"); + clk_disable_unprepare(clk); + return ret; + } + + st_wdog_setup(st_wdog, true); + + dev_info(&pdev->dev, "LPC Watchdog driver registered, reset type is %s", + st_wdog->warm_reset ? "warm" : "cold"); + + return ret; +} + +static int st_wdog_remove(struct platform_device *pdev) +{ + struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev); + + st_wdog_setup(st_wdog, false); + watchdog_unregister_device(&st_wdog_dev); + clk_disable_unprepare(st_wdog->clk); + + return 0; +} + +#ifdef CONFIG_PM_SLEEP +static int st_wdog_suspend(struct device *dev) +{ + struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev); + + if (watchdog_active(&st_wdog_dev)) + st_wdog_stop(&st_wdog_dev); + + st_wdog_setup(st_wdog, false); + + clk_disable(st_wdog->clk); + + return 0; +} + +static int st_wdog_resume(struct device *dev) +{ + struct st_wdog *st_wdog = watchdog_get_drvdata(&st_wdog_dev); + int ret; + + ret = clk_enable(st_wdog->clk); + if (ret) { + dev_err(dev, "Unable to re-enable clock\n"); + watchdog_unregister_device(&st_wdog_dev); + clk_unprepare(st_wdog->clk); + return ret; + } + + st_wdog_setup(st_wdog, true); + + if (watchdog_active(&st_wdog_dev)) { + st_wdog_load_timer(st_wdog, st_wdog_dev.timeout); + st_wdog_start(&st_wdog_dev); + } + + return 0; +} +#endif + +static SIMPLE_DEV_PM_OPS(st_wdog_pm_ops, + st_wdog_suspend, + st_wdog_resume); + +static struct platform_driver st_wdog_driver = { + .driver = { + .name = "st-lpc-wdt", + .pm = &st_wdog_pm_ops, + .of_match_table = st_wdog_match, + }, + .probe = st_wdog_probe, + .remove = st_wdog_remove, +}; +module_platform_driver(st_wdog_driver); + +MODULE_AUTHOR("David Paris "); +MODULE_DESCRIPTION("ST LPC Watchdog Driver"); +MODULE_LICENSE("GPL");