From nobody Mon Nov 25 05:12:22 2024 Received: from TWMBX01.aspeed.com (mail.aspeedtech.com [211.20.114.72]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 0E84A1E765C; Wed, 30 Oct 2024 10:47:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=211.20.114.72 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730285256; cv=none; b=f6x2WAb2ugEbKCaFOfqmMjh81YtQvWo/KVfv1YyS7Rp4kp1HcSjkUfDvNmkmI8EcEeAK5Y2HOWPDCdLm9uyAR9d2DNz5M0sVqjcLJaO06dluGDEFuN2mJgiwZEfz5HpFV9iSALAVXBJ9c60GDnD2vlNYlloGkqRjiqiXkq+59Mg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730285256; c=relaxed/simple; bh=NfdECQjhLdCrDtfug5grGVQRxCB3pq6AgqaEH3NDC6g=; h=From:To:CC:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=Gh0GXwHeXX0E9t48Qq+FT0F+QJlYkLj6Z+4zIVoC98Al+fm1YtlF+mTlchKmOHjfirdNi2pw4JWrFP9wtHiRcAIcHOPthyAtm4X2IOagz4+APTgR/FnPi7N8p0ieF4KDyfkh1N1uaF6PmEQ2OZRVcG4PAOaKb1j2R6MT7wMIMNk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=aspeedtech.com; spf=pass smtp.mailfrom=aspeedtech.com; arc=none smtp.client-ip=211.20.114.72 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=aspeedtech.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=aspeedtech.com Received: from TWMBX01.aspeed.com (192.168.0.62) by TWMBX01.aspeed.com (192.168.0.62) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.2.1258.12; Wed, 30 Oct 2024 18:47:18 +0800 Received: from aspeedtech.com (192.168.10.152) by TWMBX01.aspeed.com (192.168.0.62) with Microsoft SMTP Server id 15.2.1258.12 via Frontend Transport; Wed, 30 Oct 2024 18:47:18 +0800 From: Chin-Ting Kuo To: , , , , , , , , , , , CC: , , , , , Subject: [PATCH v3 2/2] watchdog: aspeed: Add support for SW restart Date: Wed, 30 Oct 2024 18:47:17 +0800 Message-ID: <20241030104717.168324-3-chin-ting_kuo@aspeedtech.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20241030104717.168324-1-chin-ting_kuo@aspeedtech.com> References: <20241030104717.168324-1-chin-ting_kuo@aspeedtech.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Since AST2600, except for HW WDT counter timeout, HW WDT reset can also be triggered by just cinfiguring some HW registers by SW directly. We named it "SW restart". Although it is "SW" restart, its mechanism is implemented by HW. Originally, system can only know it is reset by WDT through a reset flag. However, since AST2600, SW can trigger the reset event consciously and directly without wait for WDT timeout. WDT counter is not enabled when SW restart is adopted. After that, an independent reset event flag will be set after systemis reset by SW. Signed-off-by: Chin-Ting Kuo --- drivers/watchdog/aspeed_wdt.c | 40 +++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) diff --git a/drivers/watchdog/aspeed_wdt.c b/drivers/watchdog/aspeed_wdt.c index add76be3ee42..1e9808d42023 100644 --- a/drivers/watchdog/aspeed_wdt.c +++ b/drivers/watchdog/aspeed_wdt.c @@ -42,6 +42,9 @@ MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped on= ce started (default=3D" =20 #define WDT_REG_OFFSET_MASK 0x00000fff =20 +/* WDT behavior control flag */ +#define WDT_RESTART_SYSTEM_SW_SUPPORT 0x00000001 + struct aspeed_wdt_scu { const char *compatible; u32 reset_status_reg; @@ -55,6 +58,7 @@ struct aspeed_wdt_config { u32 irq_shift; u32 irq_mask; u32 reg_size; + u32 flags; struct aspeed_wdt_scu scu; }; =20 @@ -71,6 +75,7 @@ static const struct aspeed_wdt_config ast2400_config =3D { .irq_shift =3D 0, .irq_mask =3D 0, .reg_size =3D 0x20, + .flags =3D 0, .scu =3D { .compatible =3D "aspeed,ast2400-scu", .reset_status_reg =3D AST2400_SCU_SYS_RESET_STATUS, @@ -85,6 +90,7 @@ static const struct aspeed_wdt_config ast2500_config =3D { .irq_shift =3D 12, .irq_mask =3D GENMASK(31, 12), .reg_size =3D 0x20, + .flags =3D 0, .scu =3D { .compatible =3D "aspeed,ast2500-scu", .reset_status_reg =3D AST2400_SCU_SYS_RESET_STATUS, @@ -99,6 +105,7 @@ static const struct aspeed_wdt_config ast2600_config =3D= { .irq_shift =3D 0, .irq_mask =3D GENMASK(31, 10), .reg_size =3D 0x40, + .flags =3D WDT_RESTART_SYSTEM_SW_SUPPORT, .scu =3D { .compatible =3D "aspeed,ast2600-scu", .reset_status_reg =3D AST2600_SCU_SYS_RESET_STATUS, @@ -136,6 +143,11 @@ MODULE_DEVICE_TABLE(of, aspeed_wdt_of_table); #define WDT_CLEAR_TIMEOUT_AND_BOOT_CODE_SELECTION BIT(0) #define WDT_RESET_MASK1 0x1c #define WDT_RESET_MASK2 0x20 +#define WDT_SW_RESET_CTRL 0x24 +#define WDT_SW_RESET_COUNT_CLEAR 0xDEADDEAD +#define WDT_SW_RESET_ENABLE 0xAEEDF123 +#define WDT_SW_RESET_MASK1 0x28 +#define WDT_SW_RESET_MASK2 0x2c =20 /* * WDT_RESET_WIDTH controls the characteristics of the external pulse (if @@ -255,10 +267,31 @@ static int aspeed_wdt_set_pretimeout(struct watchdog_= device *wdd, return 0; } =20 +static void aspeed_wdt_sw_reset(struct watchdog_device *wdd) +{ + struct aspeed_wdt *wdt =3D to_aspeed_wdt(wdd); + u32 ctrl =3D WDT_CTRL_RESET_MODE_SOC | + WDT_CTRL_RESET_SYSTEM; + + writel(ctrl, wdt->base + WDT_CTRL); + writel(WDT_SW_RESET_COUNT_CLEAR, + wdt->base + WDT_SW_RESET_CTRL); + writel(WDT_SW_RESET_ENABLE, wdt->base + WDT_SW_RESET_CTRL); + + /* system must be reset immediately */ + mdelay(1000); +} + static int aspeed_wdt_restart(struct watchdog_device *wdd, unsigned long action, void *data) { struct aspeed_wdt *wdt =3D to_aspeed_wdt(wdd); + const struct aspeed_wdt_config *cfg =3D wdt->cfg; + + if (cfg->flags & WDT_RESTART_SYSTEM_SW_SUPPORT) { + aspeed_wdt_sw_reset(wdd); + return 0; + } =20 wdt->ctrl &=3D ~WDT_CTRL_BOOT_SECONDARY; aspeed_wdt_enable(wdt, 128 * WDT_RATE_1MHZ / 1000); @@ -529,6 +562,13 @@ static int aspeed_wdt_probe(struct platform_device *pd= ev) if (nrstmask > 1) writel(reset_mask[1], wdt->base + WDT_RESET_MASK2); } + + if (wdt->cfg->flags & WDT_RESTART_SYSTEM_SW_SUPPORT) { + reg =3D readl(wdt->base + WDT_RESET_MASK1); + writel(reg, wdt->base + WDT_SW_RESET_MASK1); + reg =3D readl(wdt->base + WDT_RESET_MASK2); + writel(reg, wdt->base + WDT_SW_RESET_MASK2); + } } =20 if (!of_property_read_u32(np, "aspeed,ext-pulse-duration", &duration)) { --=20 2.34.1