Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752692AbaKKL3a (ORCPT ); Tue, 11 Nov 2014 06:29:30 -0500 Received: from mailgw01.mediatek.com ([210.61.82.183]:53369 "EHLO mailgw01.mediatek.com" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1750814AbaKKL31 (ORCPT ); Tue, 11 Nov 2014 06:29:27 -0500 X-Listener-Flag: 11101 Subject: Re: [PATCH 1/2] watchdog: Add driver for Mediatek mt6589 watchdog From: Eddie Huang To: Matthias Brugger CC: "wim@iguana.be" , "robh+dt@kernel.org" , "pawel.moll@arm.com" , "mark.rutland@arm.com" , "ijc+devicetree@hellion.org.uk" , "galak@codeaurora.org" , "grant.likely@linaro.org" , "heiko@sntech.de" , "yingjoe.chen@gmail.com" , "linux-kernel@vger.kernel.org" , "ibanezchen@gmail.com" , "linux-arm-kernel@lists.infradead.org" , "linux-watchdog@vger.kernel.org" , , In-Reply-To: <1414428092-20725-2-git-send-email-matthias.bgg@gmail.com> References: <1414428092-20725-1-git-send-email-matthias.bgg@gmail.com> <1414428092-20725-2-git-send-email-matthias.bgg@gmail.com> Content-Type: text/plain; charset="UTF-8" Date: Tue, 11 Nov 2014 19:29:17 +0800 Message-ID: <1415705357.1776.11.camel@mtksdaap41> MIME-Version: 1.0 X-Mailer: Evolution 2.28.3 Content-Transfer-Encoding: 7bit X-MTK: N Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2014-10-28 at 00:41 +0800, Matthias Brugger wrote: > This patch adds a driver for the Mediatek mt6589 SoC integrated > watchdog. > > Signed-off-by: Matthias Brugger > --- > drivers/watchdog/Kconfig | 10 ++ > drivers/watchdog/Makefile | 1 + > drivers/watchdog/mtk_wdt.c | 264 +++++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 275 insertions(+) > create mode 100644 drivers/watchdog/mtk_wdt.c > > diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig > index d0107d4..fcbca1b 100644 > --- a/drivers/watchdog/Kconfig > +++ b/drivers/watchdog/Kconfig > @@ -505,6 +505,16 @@ config MESON_WATCHDOG > To compile this driver as a module, choose M here: the > module will be called meson_wdt. > > +config MEDIATEK_WATCHDOG > + tristate "Mediatek SoCs watchdog support" > + depends on ARCH_MEDIATEK > + select WATCHDOG_CORE > + help > + Say Y here to include support for the watchdog timer > + in Mediatek SoCs. > + To compile this driver as a module, choose M here: the > + module will be called mtk_wdt. > + > # AVR32 Architecture > > config AT32AP700X_WDT > diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile > index c569ec8..0d4821f 100644 > --- a/drivers/watchdog/Makefile > +++ b/drivers/watchdog/Makefile > @@ -63,6 +63,7 @@ obj-$(CONFIG_QCOM_WDT) += qcom-wdt.o > obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o > obj-$(CONFIG_TEGRA_WATCHDOG) += tegra_wdt.o > obj-$(CONFIG_MESON_WATCHDOG) += meson_wdt.o > +obj-$(CONFIG_MEDIATEK_WATCHDOG) += mtk_wdt.o > > # AVR32 Architecture > obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o > diff --git a/drivers/watchdog/mtk_wdt.c b/drivers/watchdog/mtk_wdt.c > new file mode 100644 > index 0000000..4624821 > --- /dev/null > +++ b/drivers/watchdog/mtk_wdt.c > @@ -0,0 +1,264 @@ > +/* > + * Mediatek Watchdog Driver > + * > + * Copyright (C) 2014 Matthias Brugger > + * > + * Matthias Brugger > + * > + * 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. > + * > + * Based on mtk_wdt.c > + */ > + > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > +#include > + > +#define WDT_MAX_TIMEOUT 31 > +#define WDT_MIN_TIMEOUT 1 > +#define WDT_LENGTH_TIMEOUT(n) ((n) << 5) > + > +#define WDT_LENGTH 0x04 > +#define WDT_LENGTH_KEY 0x8 > + > +#define WDT_RST 0x08 > +#define WDT_RST_RELOAD 0x1971 > + > +#define WDT_MODE 0x00 > +#define WDT_MODE_EN (1 << 0) > +#define WDT_MODE_EXT_POL_LOW (0 << 1) > +#define WDT_MODE_EXT_POL_HIGH (1 << 1) > +#define WDT_MODE_EXRST_EN (1 << 2) > +#define WDT_MODE_IRQ_EN (1 << 3) > +#define WDT_MODE_AUTO_START (1 << 4) > +#define WDT_MODE_DUAL_EN (1 << 6) > +#define WDT_MODE_KEY 0x22000000 > + > +#define WDT_SWRST 0x14 > +#define WDT_SWRST_KEY 0x1209 > + > +#define DRV_NAME "mtk-wdt" > +#define DRV_VERSION "1.0" > + > +static bool nowayout = WATCHDOG_NOWAYOUT; > +static unsigned int timeout = WDT_MAX_TIMEOUT; > + > +struct mtk_wdt_dev { > + struct watchdog_device wdt_dev; > + void __iomem *wdt_base; > + struct notifier_block restart_handler; > +}; > + > +static int mtk_reset_handler(struct notifier_block *this, unsigned long mode, > + void *cmd) > +{ > + struct mtk_wdt_dev *mtk_wdt = container_of(this, > + struct mtk_wdt_dev, > + restart_handler); > + void __iomem *wdt_base = mtk_wdt->wdt_base; > + u32 reg; > + > + /* Enable watchdog */ > + reg = readl(wdt_base + WDT_MODE); > + reg |= WDT_MODE_EN; > + writel(reg, wdt_base + WDT_MODE); > + > + /* Reload counter */ > + writel(WDT_RST_RELOAD, wdt_base + WDT_RST); > + > + /* Reset system */ > + writel(WDT_SWRST_KEY, wdt_base + WDT_SWRST); > + > + while (1) { > + mdelay(5); > + writel(WDT_SWRST_KEY, wdt_base + WDT_SWRST); > + } > + return NOTIFY_DONE; > + > +} > + > +static int mtk_wdt_ping(struct watchdog_device *wdt_dev) > +{ > + struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev); > + void __iomem *wdt_base = mtk_wdt->wdt_base; > + > + iowrite32(WDT_RST_RELOAD, wdt_base + WDT_RST); > + > + return 0; > +} > + > +static int mtk_wdt_set_timeout(struct watchdog_device *wdt_dev, > + unsigned int timeout) > +{ > + struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev); > + void __iomem *wdt_base = mtk_wdt->wdt_base; > + u32 reg; > + > + mtk_wdt->wdt_dev.timeout = timeout; > + > + /* One bit is the value of 512 ticks > + * The clock has 32 KHz > + */ > + reg = WDT_LENGTH_TIMEOUT(timeout << 6) | WDT_LENGTH_KEY; > + iowrite32(reg, wdt_base + WDT_LENGTH); > + > + mtk_wdt_ping(wdt_dev); > + > + return 0; > +} > + > +static int mtk_wdt_stop(struct watchdog_device *wdt_dev) > +{ > + struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev); > + void __iomem *wdt_base = mtk_wdt->wdt_base; > + u32 reg; > + > + reg = readl(wdt_base + WDT_MODE); > + reg &= ~(WDT_MODE_EN); > + iowrite32(reg, wdt_base + WDT_MODE); > + > + return 0; > +} > + > +static int mtk_wdt_start(struct watchdog_device *wdt_dev) > +{ > + u32 reg; > + struct mtk_wdt_dev *mtk_wdt = watchdog_get_drvdata(wdt_dev); > + void __iomem *wdt_base = mtk_wdt->wdt_base; > + u32 ret; > + > + ret = mtk_wdt_set_timeout(&mtk_wdt->wdt_dev, > + mtk_wdt->wdt_dev.timeout); > + if (ret < 0) > + return ret; > + > + reg = ioread32(wdt_base + WDT_MODE); > + reg |= (WDT_MODE_EN | WDT_MODE_KEY); According to datasheet, default value of register WDT_MODE bit6 is 1. Which means when reach timeout, still need another timeout time to restart the system. Should clear this bit to disable dual mode: reg &= ~(WDT_MODE_DUAL_EN); > + iowrite32(reg, wdt_base + WDT_MODE); > + > + return 0; > +} > + > +static const struct watchdog_info mtk_wdt_info = { > + .identity = DRV_NAME, > + .options = WDIOF_SETTIMEOUT | > + WDIOF_KEEPALIVEPING | > + WDIOF_MAGICCLOSE, > +}; > + > +static const struct watchdog_ops mtk_wdt_ops = { > + .owner = THIS_MODULE, > + .start = mtk_wdt_start, > + .stop = mtk_wdt_stop, > + .ping = mtk_wdt_ping, > + .set_timeout = mtk_wdt_set_timeout, > +}; > + > +static int mtk_wdt_probe(struct platform_device *pdev) > +{ > + struct mtk_wdt_dev *mtk_wdt; > + struct resource *res; > + int err; > + > + mtk_wdt = devm_kzalloc(&pdev->dev, sizeof(*mtk_wdt), GFP_KERNEL); > + if (!mtk_wdt) > + return -EINVAL; > + > + platform_set_drvdata(pdev, mtk_wdt); > + > + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); > + mtk_wdt->wdt_base = devm_ioremap_resource(&pdev->dev, res); > + if (IS_ERR(mtk_wdt->wdt_base)) > + return PTR_ERR(mtk_wdt->wdt_base); > + > + mtk_wdt->wdt_dev.info = &mtk_wdt_info; > + mtk_wdt->wdt_dev.ops = &mtk_wdt_ops; > + mtk_wdt->wdt_dev.timeout = WDT_MAX_TIMEOUT; > + mtk_wdt->wdt_dev.max_timeout = WDT_MAX_TIMEOUT; > + mtk_wdt->wdt_dev.min_timeout = WDT_MIN_TIMEOUT; > + mtk_wdt->wdt_dev.parent = &pdev->dev; > + > + watchdog_init_timeout(&mtk_wdt->wdt_dev, timeout, &pdev->dev); > + watchdog_set_nowayout(&mtk_wdt->wdt_dev, nowayout); > + > + watchdog_set_drvdata(&mtk_wdt->wdt_dev, mtk_wdt); > + > + mtk_wdt_stop(&mtk_wdt->wdt_dev); > + > + err = watchdog_register_device(&mtk_wdt->wdt_dev); > + if (unlikely(err)) > + return err; > + > + mtk_wdt->restart_handler.notifier_call = mtk_reset_handler; > + mtk_wdt->restart_handler.priority = 128; > + err = register_restart_handler(&mtk_wdt->restart_handler); > + if (err) > + dev_err(&pdev->dev, > + "cannot register restart handler (err=%d)\n", err); > + > + dev_info(&pdev->dev, "Watchdog enabled (timeout=%d sec, nowayout=%d)", > + mtk_wdt->wdt_dev.timeout, nowayout); > + > + return 0; > +} > + > +static int mtk_wdt_remove(struct platform_device *pdev) > +{ > + struct mtk_wdt_dev *mtk_wdt = platform_get_drvdata(pdev); > + > + unregister_restart_handler(&mtk_wdt->restart_handler); > + > + watchdog_unregister_device(&mtk_wdt->wdt_dev); > + watchdog_set_drvdata(&mtk_wdt->wdt_dev, NULL); > + > + return 0; > +} > + > +static const struct of_device_id mtk_wdt_dt_ids[] = { > + { .compatible = "mediatek,mt6589-wdt" }, > + { /* sentinel */ } > +}; > +MODULE_DEVICE_TABLE(of, mtk_wdt_dt_ids); > + > +static struct platform_driver mtk_wdt_driver = { > + .probe = mtk_wdt_probe, > + .remove = mtk_wdt_remove, > + .driver = { > + .owner = THIS_MODULE, > + .name = DRV_NAME, > + .of_match_table = mtk_wdt_dt_ids, > + }, > +}; > + > +module_platform_driver(mtk_wdt_driver); > + > +module_param(timeout, uint, 0); > +MODULE_PARM_DESC(timeout, "Watchdog heartbeat in seconds"); > + > +module_param(nowayout, bool, 0); > +MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started (default=" > + __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); > + > +MODULE_LICENSE("GPL"); > +MODULE_AUTHOR("Matthias Brugger "); > +MODULE_DESCRIPTION("Mediatek WatchDog Timer Driver"); > +MODULE_VERSION(DRV_VERSION); > -- > 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/