From patchwork Fri Nov 15 20:58:00 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Markus Mayer X-Patchwork-Id: 3189991 Return-Path: X-Original-To: patchwork-linux-arm@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 1A9E8C045B for ; Fri, 15 Nov 2013 21:04:51 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id D1AE120922 for ; Fri, 15 Nov 2013 21:04:49 +0000 (UTC) Received: from casper.infradead.org (casper.infradead.org [85.118.1.10]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 5145320751 for ; Fri, 15 Nov 2013 21:04:48 +0000 (UTC) Received: from merlin.infradead.org ([2001:4978:20e::2]) by casper.infradead.org with esmtps (Exim 4.80.1 #2 (Red Hat Linux)) id 1VhQZG-0004SF-Hh; Fri, 15 Nov 2013 21:04:42 +0000 Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VhQZE-0008Ho-0p; Fri, 15 Nov 2013 21:04:40 +0000 Received: from mms3.broadcom.com ([216.31.210.19]) by merlin.infradead.org with esmtp (Exim 4.80.1 #2 (Red Hat Linux)) id 1VhQZ0-0008FD-3Y for linux-arm-kernel@lists.infradead.org; Fri, 15 Nov 2013 21:04:28 +0000 Received: from [10.9.208.57] by mms3.broadcom.com with ESMTP (Broadcom SMTP Relay (Email Firewall v6.5)); Fri, 15 Nov 2013 13:03:08 -0800 X-Server-Uuid: B86B6450-0931-4310-942E-F00ED04CA7AF Received: from IRVEXCHSMTP2.corp.ad.broadcom.com (10.9.207.52) by IRVEXCHCAS08.corp.ad.broadcom.com (10.9.208.57) with Microsoft SMTP Server (TLS) id 14.1.438.0; Fri, 15 Nov 2013 12:58:10 -0800 Received: from mail-irva-13.broadcom.com (10.10.10.20) by IRVEXCHSMTP2.corp.ad.broadcom.com (10.9.207.52) with Microsoft SMTP Server id 14.1.438.0; Fri, 15 Nov 2013 12:58:10 -0800 Received: from mail.broadcom.com (lbrmn-lnxub70.ric.broadcom.com [10.136.8.215]) by mail-irva-13.broadcom.com (Postfix) with ESMTP id A37F7246B4; Fri, 15 Nov 2013 12:58:06 -0800 (PST) From: "Markus Mayer" To: "Wim Van Sebroeck" , "Guenter Roeck" , "Christian Daudt" Subject: [PATCH v2 1/2] watchdog: bcm281xx: Watchdog Driver Date: Fri, 15 Nov 2013 12:58:00 -0800 Message-ID: <1384549081-9571-2-git-send-email-markus.mayer@linaro.org> X-Mailer: git-send-email 1.7.9.5 In-Reply-To: <1384549081-9571-1-git-send-email-markus.mayer@linaro.org> References: <1384549081-9571-1-git-send-email-markus.mayer@linaro.org> MIME-Version: 1.0 X-WSS-ID: 7E9856881SC8451387-08-01 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20131115_160426_493506_4FD9AB4A X-CRM114-Status: GOOD ( 27.29 ) X-Spam-Score: -3.5 (---) Cc: Linux Watchdog List , Linaro Patches , Linux Kernel Mailing List , Markus Mayer , Matt Porter , ARM Kernel List X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+patchwork-linux-arm=patchwork.kernel.org@lists.infradead.org X-Spam-Status: No, score=-4.2 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_MED, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=unavailable version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP This commit adds support for the watchdog timer used on the BCM281xx family of SoCs. Signed-off-by: Markus Mayer Reviewed-by: Matt Porter --- drivers/watchdog/Kconfig | 22 +++ drivers/watchdog/Makefile | 1 + drivers/watchdog/bcm_kona_wdt.c | 367 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 390 insertions(+) create mode 100644 drivers/watchdog/bcm_kona_wdt.c diff --git a/drivers/watchdog/Kconfig b/drivers/watchdog/Kconfig index d1d53f3..fe8bd21 100644 --- a/drivers/watchdog/Kconfig +++ b/drivers/watchdog/Kconfig @@ -1121,6 +1121,28 @@ config BCM2835_WDT To compile this driver as a loadable module, choose M here. The module will be called bcm2835_wdt. +config BCM_KONA_WDT + tristate "BCM Kona Watchdog" + depends on ARCH_BCM + select WATCHDOG_CORE + help + Support for the watchdog timer on the following Broadcom BCM281xx + family, which includes BCM11130, BCM11140, BCM11351, BCM28145 and + BCM28155 variants. + + Say 'Y' or 'M' here to enable the driver. The module will be called + bcm_kona_wdt. + +config BCM_KONA_WDT_DEBUG + bool "DEBUGFS support for BCM Kona Watchdog" + depends on BCM_KONA_WDT + help + If enabled, adds /sys/kernel/debug/bcm-kona-wdt/info which provides + access to the driver's internal data structures as well as watchdog + timer hardware registres. + + If in doubt, say 'N'. + config LANTIQ_WDT tristate "Lantiq SoC watchdog" depends on LANTIQ diff --git a/drivers/watchdog/Makefile b/drivers/watchdog/Makefile index 6c5bb27..7c860ca 100644 --- a/drivers/watchdog/Makefile +++ b/drivers/watchdog/Makefile @@ -55,6 +55,7 @@ obj-$(CONFIG_IMX2_WDT) += imx2_wdt.o obj-$(CONFIG_UX500_WATCHDOG) += ux500_wdt.o obj-$(CONFIG_RETU_WATCHDOG) += retu_wdt.o obj-$(CONFIG_BCM2835_WDT) += bcm2835_wdt.o +obj-$(CONFIG_BCM_KONA_WDT) += bcm_kona_wdt.o # AVR32 Architecture obj-$(CONFIG_AT32AP700X_WDT) += at32ap700x_wdt.o diff --git a/drivers/watchdog/bcm_kona_wdt.c b/drivers/watchdog/bcm_kona_wdt.c new file mode 100644 index 0000000..5a03d5a --- /dev/null +++ b/drivers/watchdog/bcm_kona_wdt.c @@ -0,0 +1,367 @@ +/* + * Copyright (C) 2013 Broadcom Corporation + * + * 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 version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; 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 +#include + +#define SECWDOG_CTRL_REG 0x00000000 +#define SECWDOG_COUNT_REG 0x00000004 + +#define SECWDOG_RESERVED_MASK 0x1dffffff +#define SECWDOG_WD_LOAD_FLAG 0x10000000 +#define SECWDOG_EN_MASK 0x08000000 +#define SECWDOG_SRSTEN_MASK 0x04000000 +#define SECWDOG_RES_MASK 0x00f00000 +#define SECWDOG_COUNT_MASK 0x000fffff + +#define SECWDOG_MAX_COUNT SECWDOG_COUNT_MASK +#define SECWDOG_CLKS_SHIFT 20 +#define SECWDOG_MAX_RES 15 +#define SECWDOG_DEFAULT_RESOLUTION 4 +#define SECWDOG_MAX_TRY 1000 + +#define SECS_TO_TICKS(x, w) ((x) << (w)->resolution) +#define TICKS_TO_SECS(x, w) ((x) >> (w)->resolution) + +#define BCM_KONA_WDT_NAME "bcm-kona-wdt" + +struct bcm_kona_wdt { + void __iomem *base; + /* + * One watchdog tick is 1/(2^resolution) seconds. Resolution can take + * the values 0-15, meaning one tick can be 1s to 30.52us. Our default + * resolution of 4 means one tick is 62.5ms. + * + * The watchdog counter is 20 bits. Depending on resolution, the maximum + * counter value of 0xfffff expires after about 12 days (resolution 0) + * down to only 32s (resolution 15). The default resolution of 4 gives + * us a maximum of about 18 hours and 12 minutes before the watchdog + * times out. + */ + int resolution; + spinlock_t lock; +#ifdef CONFIG_BCM_KONA_WDT_DEBUG + struct dentry *debugfs; +#endif +}; + +#ifdef CONFIG_BCM_KONA_WDT_DEBUG +static unsigned long busy_count = 0; +#endif + +static int secure_register_read(void __iomem *addr) +{ + uint32_t val; + unsigned count = 0; + + /* + * If the WD_LOAD_FLAG is set, the watchdog counter field is being + * updated in hardware. Once the WD timer is updated in hardware, it + * gets cleared. + */ + do { + if (unlikely(count > 1)) { + udelay(5); +#ifdef CONFIG_BCM_KONA_WDT_DEBUG + /* To keep track how often we get stalled here. */ + busy_count++; +#endif + } + val = readl_relaxed(addr); + count++; + } while ((val & SECWDOG_WD_LOAD_FLAG) && count < SECWDOG_MAX_TRY); + + /* This is the only place we return a negative value. */ + if (val & SECWDOG_WD_LOAD_FLAG) { + return -ETIMEDOUT; + } + + /* We always mask out reserved bits. */ + val &= SECWDOG_RESERVED_MASK; + + return val; +} + +#ifdef CONFIG_BCM_KONA_WDT_DEBUG + +static int bcm_kona_wdt_dbg_show(struct seq_file *s, void *data) +{ + int ctl_val, cur_val, ret; + unsigned long flags; + struct bcm_kona_wdt *wdt = s->private; + + if (!wdt) + return seq_printf(s, "No device pointer\n"); + + spin_lock_irqsave(&wdt->lock, flags); + ctl_val = secure_register_read(wdt->base + SECWDOG_CTRL_REG); + cur_val = secure_register_read(wdt->base + SECWDOG_COUNT_REG); + spin_unlock_irqrestore(&wdt->lock, flags); + + if (ctl_val < 0 || cur_val < 0) { + ret = seq_printf(s, "Error accessing hardware\n"); + } else { + int ctl, cur, ctl_sec, cur_sec, res; + + ctl = ctl_val & SECWDOG_COUNT_MASK; + res = (ctl_val & SECWDOG_RES_MASK) >> SECWDOG_CLKS_SHIFT; + cur = cur_val & SECWDOG_COUNT_MASK; + ctl_sec = TICKS_TO_SECS(ctl, wdt); + cur_sec = TICKS_TO_SECS(cur, wdt); + ret = seq_printf(s, "Resolution: %d / %d\n" + "Control: %d s / %d (%#x) ticks\n" + "Current: %d s / %d (%#x) ticks\n" + "Busy count: %lu\n", res, + wdt->resolution, ctl_sec, ctl, ctl, cur_sec, + cur, cur, busy_count); + } + + return ret; +} + +static int bcm_kona_dbg_open(struct inode *inode, struct file *file) +{ + return single_open(file, bcm_kona_wdt_dbg_show, inode->i_private); +} + +static const struct file_operations bcm_kona_dbg_operations = { + .open = bcm_kona_dbg_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static struct dentry *bcm_kona_wdt_debugfs_init(struct bcm_kona_wdt *wdt, + struct watchdog_device *wdd) +{ + struct dentry *dir; + + dir = debugfs_create_dir(BCM_KONA_WDT_NAME, NULL); + if (IS_ERR_OR_NULL(dir)) + return NULL; + + if (debugfs_create_file("info", S_IFREG | S_IRUGO, dir, wdt, + &bcm_kona_dbg_operations)) + return dir; + + /* Clean up */ + debugfs_remove_recursive(dir); + return NULL; +} + +static void bcm_kona_debugfs_exit(struct dentry *dir) +{ + debugfs_remove_recursive(dir); +} + +#endif /* CONFIG_BCM_KONA_WDT_DEBUG */ + +static int bcm_kona_wdt_ctrl_reg_modify(struct bcm_kona_wdt *wdt, + unsigned mask, unsigned newval) +{ + int val; + unsigned long flags; + int ret = 0; + + spin_lock_irqsave(&wdt->lock, flags); + + val = secure_register_read(wdt->base + SECWDOG_CTRL_REG); + if (val < 0) { + ret = val; + } else { + val &= ~mask; + val |= newval; + writel_relaxed(val, wdt->base + SECWDOG_CTRL_REG); + } + + spin_unlock_irqrestore(&wdt->lock, flags); + + return ret; +} + +static int bcm_kona_wdt_set_resolution_reg(struct bcm_kona_wdt *wdt) +{ + if (wdt->resolution > SECWDOG_MAX_RES) + return -EINVAL; + + return bcm_kona_wdt_ctrl_reg_modify(wdt, SECWDOG_RES_MASK, + wdt->resolution << SECWDOG_CLKS_SHIFT); +} + +static int bcm_kona_wdt_set_timeout_reg(struct watchdog_device *wdog, + unsigned watchdog_flags) +{ + struct bcm_kona_wdt *wdt = watchdog_get_drvdata(wdog); + + return bcm_kona_wdt_ctrl_reg_modify(wdt, SECWDOG_COUNT_MASK, + SECS_TO_TICKS(wdog->timeout, wdt) | + watchdog_flags); +} + +static int bcm_kona_wdt_set_timeout(struct watchdog_device *wdog, + unsigned int t) +{ + wdog->timeout = t; + return 0; +} + +static unsigned int bcm_kona_wdt_get_timeleft(struct watchdog_device *wdog) +{ + struct bcm_kona_wdt *wdt = watchdog_get_drvdata(wdog); + int val; + unsigned long flags; + + spin_lock_irqsave(&wdt->lock, flags); + val = secure_register_read(wdt->base + SECWDOG_COUNT_REG); + spin_unlock_irqrestore(&wdt->lock, flags); + + if (val < 0) + return val; + + return TICKS_TO_SECS(val & SECWDOG_COUNT_MASK, wdt); +} + +static int bcm_kona_wdt_start(struct watchdog_device *wdog) +{ + return bcm_kona_wdt_set_timeout_reg(wdog, + SECWDOG_EN_MASK | SECWDOG_SRSTEN_MASK); +} + +static int bcm_kona_wdt_stop(struct watchdog_device *wdog) +{ + struct bcm_kona_wdt *wdt = watchdog_get_drvdata(wdog); + + return bcm_kona_wdt_ctrl_reg_modify(wdt, SECWDOG_EN_MASK | + SECWDOG_SRSTEN_MASK, 0); +} + +static struct watchdog_ops bcm_kona_wdt_ops = { + .owner = THIS_MODULE, + .start = bcm_kona_wdt_start, + .stop = bcm_kona_wdt_stop, + .set_timeout = bcm_kona_wdt_set_timeout, + .get_timeleft = bcm_kona_wdt_get_timeleft, +}; + +static struct watchdog_info bcm_kona_wdt_info = { + .options = WDIOF_SETTIMEOUT | WDIOF_MAGICCLOSE | + WDIOF_KEEPALIVEPING, + .identity = "Broadcom Kona Watchdog Timer", +}; + +static struct watchdog_device bcm_kona_wdt_wdd = { + .info = &bcm_kona_wdt_info, + .ops = &bcm_kona_wdt_ops, + .min_timeout = 1, + .max_timeout = SECWDOG_MAX_COUNT >> SECWDOG_DEFAULT_RESOLUTION, + .timeout = SECWDOG_MAX_COUNT >> SECWDOG_DEFAULT_RESOLUTION, +}; + +static void bcm_kona_wdt_shutdown(struct platform_device *pdev) +{ + bcm_kona_wdt_stop(&bcm_kona_wdt_wdd); +} + +static int bcm_kona_wdt_probe(struct platform_device *pdev) +{ + struct device *dev = &pdev->dev; + struct bcm_kona_wdt *wdt; + struct resource *res; + int ret; + + wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); + if (!wdt) { + dev_err(dev, "Failed to allocate memory for watchdog device"); + return -ENOMEM; + } + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + wdt->base = devm_ioremap_resource(dev, res); + if (IS_ERR(wdt->base)) + return -ENODEV; + + wdt->resolution = SECWDOG_DEFAULT_RESOLUTION; + ret = bcm_kona_wdt_set_resolution_reg(wdt); + if (ret) { + dev_err(dev, "Failed to set resolution (error: %d)", ret); + return ret; + } + + spin_lock_init(&wdt->lock); + platform_set_drvdata(pdev, wdt); + watchdog_set_drvdata(&bcm_kona_wdt_wdd, wdt); + + ret = bcm_kona_wdt_set_timeout_reg(&bcm_kona_wdt_wdd, 0); + if (ret) { + dev_err(dev, "Failed set watchdog timeout"); + return ret; + } + + ret = watchdog_register_device(&bcm_kona_wdt_wdd); + if (ret) { + dev_err(dev, "Failed to register watchdog device"); + return ret; + } + +#ifdef CONFIG_BCM_KONA_WDT_DEBUG + wdt->debugfs = bcm_kona_wdt_debugfs_init(wdt, &bcm_kona_wdt_wdd); +#endif + dev_dbg(dev, "Broadcom Kona Watchdog Timer"); + + return 0; +} + +static int bcm_kona_wdt_remove(struct platform_device *pdev) +{ +#ifdef CONFIG_BCM_KONA_WDT_DEBUG + struct bcm_kona_wdt *wdt = platform_get_drvdata(pdev); + + if (wdt->debugfs) + bcm_kona_debugfs_exit(wdt->debugfs); +#endif /* CONFIG_BCM_KONA_WDT_DEBUG */ + bcm_kona_wdt_shutdown(pdev); + watchdog_unregister_device(&bcm_kona_wdt_wdd); + dev_dbg(&pdev->dev, "Watchdog driver disabled"); + + return 0; +} + +static const struct of_device_id bcm_kona_wdt_of_match[] = { + { .compatible = "brcm,kona-wdt", }, + {}, +}; +MODULE_DEVICE_TABLE(of, bcm_kona_wdt_of_match); + +static struct platform_driver bcm_kona_wdt_driver = { + .driver = { + .name = BCM_KONA_WDT_NAME, + .owner = THIS_MODULE, + .of_match_table = bcm_kona_wdt_of_match, + }, + .probe = bcm_kona_wdt_probe, + .remove = bcm_kona_wdt_remove, + .shutdown = bcm_kona_wdt_shutdown, +}; + +module_platform_driver(bcm_kona_wdt_driver); + +MODULE_AUTHOR("Markus Mayer "); +MODULE_DESCRIPTION("Broadcom Kona Watchdog Driver"); +MODULE_LICENSE("GPL v2");