From patchwork Mon Jul 13 13:18:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tero Kristo X-Patchwork-Id: 11659737 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 78829138C for ; Mon, 13 Jul 2020 13:26:14 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 56988206F4 for ; Mon, 13 Jul 2020 13:26:14 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=ti.com header.i=@ti.com header.b="p9556Dgm" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729631AbgGMN0O (ORCPT ); Mon, 13 Jul 2020 09:26:14 -0400 Received: from lelv0143.ext.ti.com ([198.47.23.248]:55130 "EHLO lelv0143.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729613AbgGMN0N (ORCPT ); Mon, 13 Jul 2020 09:26:13 -0400 Received: from fllv0034.itg.ti.com ([10.64.40.246]) by lelv0143.ext.ti.com (8.15.2/8.15.2) with ESMTP id 06DDIWtv090683; Mon, 13 Jul 2020 08:18:32 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ti.com; s=ti-com-17Q1; t=1594646312; bh=wQ0AjsWp9AHSyNL3eQMx/G1gq1SORFAJ4yWvonHRb60=; h=From:To:CC:Subject:Date:In-Reply-To:References; b=p9556DgmA5at/waqCveAf70Ob6C7a91cGe4W6NKkiCiXGbX3fmFkmnHv4t5n882Wl ji53gF6bJqxeUmSG1n4XNb2NcK9KHGlCr6TXWhfVhMuuYWCpOhDX2Dkffx5tq5XGx7 9qZb7n1+pxFcYAGtVezOfgJQ3XMmiqRC2+yUlCak= Received: from DLEE101.ent.ti.com (dlee101.ent.ti.com [157.170.170.31]) by fllv0034.itg.ti.com (8.15.2/8.15.2) with ESMTPS id 06DDIWbP042059 (version=TLSv1.2 cipher=AES256-GCM-SHA384 bits=256 verify=FAIL); Mon, 13 Jul 2020 08:18:32 -0500 Received: from DLEE102.ent.ti.com (157.170.170.32) by DLEE101.ent.ti.com (157.170.170.31) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3; Mon, 13 Jul 2020 08:18:31 -0500 Received: from lelv0326.itg.ti.com (10.180.67.84) by DLEE102.ent.ti.com (157.170.170.32) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256) id 15.1.1979.3 via Frontend Transport; Mon, 13 Jul 2020 08:18:31 -0500 Received: from sokoban.bb.dnainternet.fi (ileax41-snat.itg.ti.com [10.172.224.153]) by lelv0326.itg.ti.com (8.15.2/8.15.2) with ESMTP id 06DDIOXr015417; Mon, 13 Jul 2020 08:18:30 -0500 From: Tero Kristo To: , , CC: , Subject: [PATCHv3 3/4] watchdog: rti-wdt: attach to running watchdog during probe Date: Mon, 13 Jul 2020 16:18:17 +0300 Message-ID: <20200713131818.825-4-t-kristo@ti.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200713131818.825-1-t-kristo@ti.com> References: <20200713131818.825-1-t-kristo@ti.com> MIME-Version: 1.0 X-EXCLAIMER-MD-CONFIG: e1e8a2fd-e40a-4ac6-ac9b-f7e9cc9ee180 Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org If the RTI watchdog is running already during probe, the driver must configure itself to match the HW. Window size and timeout is probed from hardware, and the last keepalive ping is adjusted to match it also. Signed-off-by: Tero Kristo Reported-by: kernel test robot Reported-by: kernel test robot --- drivers/watchdog/rti_wdt.c | 111 +++++++++++++++++++++++++++++++++---- 1 file changed, 101 insertions(+), 10 deletions(-) diff --git a/drivers/watchdog/rti_wdt.c b/drivers/watchdog/rti_wdt.c index d456dd72d99a..45dfc546e371 100644 --- a/drivers/watchdog/rti_wdt.c +++ b/drivers/watchdog/rti_wdt.c @@ -35,7 +35,11 @@ #define RTIWWDRX_NMI 0xa -#define RTIWWDSIZE_50P 0x50 +#define RTIWWDSIZE_50P 0x50 +#define RTIWWDSIZE_25P 0x500 +#define RTIWWDSIZE_12P5 0x5000 +#define RTIWWDSIZE_6P25 0x50000 +#define RTIWWDSIZE_3P125 0x500000 #define WDENABLE_KEY 0xa98559da @@ -48,7 +52,7 @@ #define DWDST BIT(1) -static int heartbeat; +static int heartbeat = DEFAULT_HEARTBEAT; /* * struct to hold data for each WDT device @@ -79,11 +83,9 @@ static int rti_wdt_start(struct watchdog_device *wdd) * be petted during the open window; not too early or not too late. * The HW configuration options only allow for the open window size * to be 50% or less than that; we obviouly want to configure the open - * window as large as possible so we select the 50% option. To avoid - * any glitches, we accommodate 5% safety margin also, so we setup - * the min_hw_hearbeat at 55% of the timeout period. + * window as large as possible so we select the 50% option. */ - wdd->min_hw_heartbeat_ms = 11 * wdd->timeout * 1000 / 20; + wdd->min_hw_heartbeat_ms = 500 * wdd->timeout; /* Generate NMI when wdt expires */ writel_relaxed(RTIWWDRX_NMI, wdt->base + RTIWWDRXCTRL); @@ -110,7 +112,48 @@ static int rti_wdt_ping(struct watchdog_device *wdd) return 0; } -static unsigned int rti_wdt_get_timeleft(struct watchdog_device *wdd) +static int rti_wdt_setup_hw_hb(struct watchdog_device *wdd, u32 wsize) +{ + /* + * RTI only supports a windowed mode, where the watchdog can only + * be petted during the open window; not too early or not too late. + * The HW configuration options only allow for the open window size + * to be 50% or less than that. + */ + switch (wsize) { + case RTIWWDSIZE_50P: + /* 50% open window => 50% min heartbeat */ + wdd->min_hw_heartbeat_ms = 500 * heartbeat; + break; + + case RTIWWDSIZE_25P: + /* 25% open window => 75% min heartbeat */ + wdd->min_hw_heartbeat_ms = 750 * heartbeat; + break; + + case RTIWWDSIZE_12P5: + /* 12.5% open window => 87.5% min heartbeat */ + wdd->min_hw_heartbeat_ms = 875 * heartbeat; + break; + + case RTIWWDSIZE_6P25: + /* 6.5% open window => 93.5% min heartbeat */ + wdd->min_hw_heartbeat_ms = 935 * heartbeat; + break; + + case RTIWWDSIZE_3P125: + /* 3.125% open window => 96.9% min heartbeat */ + wdd->min_hw_heartbeat_ms = 969 * heartbeat; + break; + + default: + return -EINVAL; + } + + return 0; +} + +static unsigned int rti_wdt_get_timeleft_ms(struct watchdog_device *wdd) { u64 timer_counter; u32 val; @@ -123,11 +166,18 @@ static unsigned int rti_wdt_get_timeleft(struct watchdog_device *wdd) timer_counter = readl_relaxed(wdt->base + RTIDWDCNTR); + timer_counter *= 1000; + do_div(timer_counter, wdt->freq); return timer_counter; } +static unsigned int rti_wdt_get_timeleft(struct watchdog_device *wdd) +{ + return rti_wdt_get_timeleft_ms(wdd) / 1000; +} + static const struct watchdog_info rti_wdt_info = { .options = WDIOF_KEEPALIVEPING, .identity = "K3 RTI Watchdog", @@ -148,6 +198,7 @@ static int rti_wdt_probe(struct platform_device *pdev) struct watchdog_device *wdd; struct rti_wdt_device *wdt; struct clk *clk; + u32 last_ping = 0; wdt = devm_kzalloc(dev, sizeof(*wdt), GFP_KERNEL); if (!wdt) @@ -169,6 +220,14 @@ static int rti_wdt_probe(struct platform_device *pdev) return -EINVAL; } + /* + * If watchdog is running at 32k clock, it is not accurate. + * Adjust frequency down in this case so that we don't pet + * the watchdog too often. + */ + if (wdt->freq < 32768) + wdt->freq = wdt->freq * 9 / 10; + pm_runtime_enable(dev); ret = pm_runtime_get_sync(dev); if (ret) { @@ -185,11 +244,8 @@ static int rti_wdt_probe(struct platform_device *pdev) wdd->min_timeout = 1; wdd->max_hw_heartbeat_ms = (WDT_PRELOAD_MAX << WDT_PRELOAD_SHIFT) / wdt->freq * 1000; - wdd->timeout = DEFAULT_HEARTBEAT; wdd->parent = dev; - watchdog_init_timeout(wdd, heartbeat, dev); - watchdog_set_drvdata(wdd, wdt); watchdog_set_nowayout(wdd, 1); watchdog_set_restart_priority(wdd, 128); @@ -201,12 +257,47 @@ static int rti_wdt_probe(struct platform_device *pdev) goto err_iomap; } + if (readl(wdt->base + RTIDWDCTRL) == WDENABLE_KEY) { + u32 time_left_ms; + u64 heartbeat_ms; + u32 wsize; + + set_bit(WDOG_HW_RUNNING, &wdd->status); + time_left_ms = rti_wdt_get_timeleft_ms(wdd); + heartbeat_ms = readl(wdt->base + RTIDWDPRLD); + heartbeat_ms <<= WDT_PRELOAD_SHIFT; + heartbeat_ms *= 1000; + heartbeat_ms /= wdt->freq; + if (heartbeat_ms / 1000 != heartbeat) + dev_warn(dev, "watchdog already running, ignoring heartbeat config!\n"); + + heartbeat = heartbeat_ms / 1000; + + wsize = readl(wdt->base + RTIWWDSIZECTRL); + ret = rti_wdt_setup_hw_hb(wdd, wsize); + if (ret) { + dev_err(dev, "bad window size.\n"); + goto err_iomap; + } + + last_ping = heartbeat_ms - time_left_ms; + if (time_left_ms > heartbeat_ms) { + dev_warn(dev, "time_left > heartbeat? Assuming last ping just before now.\n"); + last_ping = 0; + } + } + + watchdog_init_timeout(wdd, heartbeat, dev); + ret = watchdog_register_device(wdd); if (ret) { dev_err(dev, "cannot register watchdog device\n"); goto err_iomap; } + if (last_ping) + watchdog_set_last_hw_keepalive(wdd, last_ping); + return 0; err_iomap: