From patchwork Mon May 4 14:14:24 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Shych X-Patchwork-Id: 11526245 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 D4739913 for ; Mon, 4 May 2020 14:14:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BCD0F2078C for ; Mon, 4 May 2020 14:14:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728917AbgEDOOi (ORCPT ); Mon, 4 May 2020 10:14:38 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:58135 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728728AbgEDOOi (ORCPT ); Mon, 4 May 2020 10:14:38 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from michaelsh@mellanox.com) with ESMTPS (AES256-SHA encrypted); 4 May 2020 17:14:32 +0300 Received: from r-build-lowlevel.mtr.labs.mlnx. (r-build-lowlevel.mtr.labs.mlnx [10.209.0.190]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id 044EEVtT022784; Mon, 4 May 2020 17:14:32 +0300 From: michaelsh@mellanox.com To: linux@roeck-us.net, wim@linux-watchdog.org, andy@infradead.org, dvhart@infradead.org Cc: linux-watchdog@vger.kernel.org, platform-driver-x86@vger.kernel.org, vadimp@mellanox.com, Michael Shych Subject: [PATCH v4 1/4] platform_data/mlxreg: support new watchdog type with longer timeout period Date: Mon, 4 May 2020 17:14:24 +0300 Message-Id: <20200504141427.17685-2-michaelsh@mellanox.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20200504141427.17685-1-michaelsh@mellanox.com> References: <20200504141427.17685-1-michaelsh@mellanox.com> Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org From: Michael Shych Add new watchdog type 3 with longer timeout period. Extend size of health_cntr field that that can be used to init watchdog timeout period. Signed-off-by: Michael Shych Reviewed-by: Vadim Pasternak Acked-by: Andy Shevchenko --- v3-v4 Platform driver part acknowledged by Andy Shevchenko --- include/linux/platform_data/mlxreg.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/include/linux/platform_data/mlxreg.h b/include/linux/platform_data/mlxreg.h index b8da8aef2446..2c5e58d1d77b 100644 --- a/include/linux/platform_data/mlxreg.h +++ b/include/linux/platform_data/mlxreg.h @@ -43,10 +43,13 @@ * * TYPE1 HW watchdog implementation exist in old systems. * All new systems have TYPE2 HW watchdog. + * TYPE3 HW watchdog can exist on all systems with new CPLD. + * TYPE3 is selected by WD capability bit. */ enum mlxreg_wdt_type { MLX_WDT_TYPE1, MLX_WDT_TYPE2, + MLX_WDT_TYPE3, }; /** @@ -90,7 +93,7 @@ struct mlxreg_core_data { umode_t mode; struct device_node *np; struct mlxreg_hotplug_device hpdev; - u8 health_cntr; + u32 health_cntr; bool attached; }; From patchwork Mon May 4 14:14:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Shych X-Patchwork-Id: 11526249 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 487E41862 for ; Mon, 4 May 2020 14:14:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3B85F2078C for ; Mon, 4 May 2020 14:14:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728728AbgEDOOi (ORCPT ); Mon, 4 May 2020 10:14:38 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:58138 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728855AbgEDOOi (ORCPT ); Mon, 4 May 2020 10:14:38 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from michaelsh@mellanox.com) with ESMTPS (AES256-SHA encrypted); 4 May 2020 17:14:33 +0300 Received: from r-build-lowlevel.mtr.labs.mlnx. (r-build-lowlevel.mtr.labs.mlnx [10.209.0.190]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id 044EEVtU022784; Mon, 4 May 2020 17:14:33 +0300 From: michaelsh@mellanox.com To: linux@roeck-us.net, wim@linux-watchdog.org, andy@infradead.org, dvhart@infradead.org Cc: linux-watchdog@vger.kernel.org, platform-driver-x86@vger.kernel.org, vadimp@mellanox.com, Michael Shych Subject: [PATCH v4 2/4] platform/x86: mlx-platform: support new watchdog type with longer timeout Date: Mon, 4 May 2020 17:14:25 +0300 Message-Id: <20200504141427.17685-3-michaelsh@mellanox.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20200504141427.17685-1-michaelsh@mellanox.com> References: <20200504141427.17685-1-michaelsh@mellanox.com> Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org From: Michael Shych Add verification of WD capability in order to distinguish between the existing WD types and new type, implemented in CPLD. Add configuration for a new WD type. Change access mode for watchdog registers. Signed-off-by: Michael Shych Reviewed-by: Vadim Pasternak Acked-by: Andy Shevchenko --- v3-v4 Platform driver part acknowledged by Andy Shevchenko --- drivers/platform/x86/mlx-platform.c | 106 ++++++++++++++++++++++++++++++++++++ 1 file changed, 106 insertions(+) diff --git a/drivers/platform/x86/mlx-platform.c b/drivers/platform/x86/mlx-platform.c index c27548fd386a..9d3371cd58d5 100644 --- a/drivers/platform/x86/mlx-platform.c +++ b/drivers/platform/x86/mlx-platform.c @@ -178,7 +178,9 @@ #define MLXPLAT_CPLD_WD_RESET_ACT_MASK GENMASK(7, 1) #define MLXPLAT_CPLD_WD_FAN_ACT_MASK (GENMASK(7, 0) & ~BIT(4)) #define MLXPLAT_CPLD_WD_COUNT_ACT_MASK (GENMASK(7, 0) & ~BIT(7)) +#define MLXPLAT_CPLD_WD_CPBLTY_MASK (GENMASK(7, 0) & ~BIT(6)) #define MLXPLAT_CPLD_WD_DFLT_TIMEOUT 30 +#define MLXPLAT_CPLD_WD3_DFLT_TIMEOUT 600 #define MLXPLAT_CPLD_WD_MAX_DEVS 2 /* mlxplat_priv - platform private data @@ -1959,6 +1961,84 @@ static struct mlxreg_core_platform_data mlxplat_mlxcpld_wd_set_type2[] = { }, }; +/* Watchdog type3: hardware implementation version 3 + * Can be on all systems. It's differentiated by WD capability bit. + * Old systems (MSN2700, MSN2410, MSN2740, MSN2100 and MSN2140) + * still have only one main watchdog. + */ +static struct mlxreg_core_data mlxplat_mlxcpld_wd_main_regs_type3[] = { + { + .label = "action", + .reg = MLXPLAT_CPLD_LPC_REG_WD2_ACT_OFFSET, + .mask = MLXPLAT_CPLD_WD_RESET_ACT_MASK, + .bit = 0, + }, + { + .label = "timeout", + .reg = MLXPLAT_CPLD_LPC_REG_WD2_TMR_OFFSET, + .mask = MLXPLAT_CPLD_WD_TYPE2_TO_MASK, + .health_cntr = MLXPLAT_CPLD_WD3_DFLT_TIMEOUT, + }, + { + .label = "timeleft", + .reg = MLXPLAT_CPLD_LPC_REG_WD2_TMR_OFFSET, + .mask = MLXPLAT_CPLD_WD_TYPE2_TO_MASK, + }, + { + .label = "ping", + .reg = MLXPLAT_CPLD_LPC_REG_WD2_ACT_OFFSET, + .mask = MLXPLAT_CPLD_WD_RESET_ACT_MASK, + .bit = 0, + }, + { + .label = "reset", + .reg = MLXPLAT_CPLD_LPC_REG_RESET_CAUSE_OFFSET, + .mask = GENMASK(7, 0) & ~BIT(6), + .bit = 6, + }, +}; + +static struct mlxreg_core_data mlxplat_mlxcpld_wd_aux_regs_type3[] = { + { + .label = "action", + .reg = MLXPLAT_CPLD_LPC_REG_WD3_ACT_OFFSET, + .mask = MLXPLAT_CPLD_WD_FAN_ACT_MASK, + .bit = 4, + }, + { + .label = "timeout", + .reg = MLXPLAT_CPLD_LPC_REG_WD3_TMR_OFFSET, + .mask = MLXPLAT_CPLD_WD_TYPE2_TO_MASK, + .health_cntr = MLXPLAT_CPLD_WD3_DFLT_TIMEOUT, + }, + { + .label = "timeleft", + .reg = MLXPLAT_CPLD_LPC_REG_WD3_TMR_OFFSET, + .mask = MLXPLAT_CPLD_WD_TYPE2_TO_MASK, + }, + { + .label = "ping", + .reg = MLXPLAT_CPLD_LPC_REG_WD3_ACT_OFFSET, + .mask = MLXPLAT_CPLD_WD_FAN_ACT_MASK, + .bit = 4, + }, +}; + +static struct mlxreg_core_platform_data mlxplat_mlxcpld_wd_set_type3[] = { + { + .data = mlxplat_mlxcpld_wd_main_regs_type3, + .counter = ARRAY_SIZE(mlxplat_mlxcpld_wd_main_regs_type3), + .version = MLX_WDT_TYPE3, + .identity = "mlx-wdt-main", + }, + { + .data = mlxplat_mlxcpld_wd_aux_regs_type3, + .counter = ARRAY_SIZE(mlxplat_mlxcpld_wd_aux_regs_type3), + .version = MLX_WDT_TYPE3, + .identity = "mlx-wdt-aux", + }, +}; + static bool mlxplat_mlxcpld_writeable_reg(struct device *dev, unsigned int reg) { switch (reg) { @@ -1989,8 +2069,10 @@ static bool mlxplat_mlxcpld_writeable_reg(struct device *dev, unsigned int reg) case MLXPLAT_CPLD_LPC_REG_WD1_TMR_OFFSET: case MLXPLAT_CPLD_LPC_REG_WD1_ACT_OFFSET: case MLXPLAT_CPLD_LPC_REG_WD2_TMR_OFFSET: + case MLXPLAT_CPLD_LPC_REG_WD2_TLEFT_OFFSET: case MLXPLAT_CPLD_LPC_REG_WD2_ACT_OFFSET: case MLXPLAT_CPLD_LPC_REG_WD3_TMR_OFFSET: + case MLXPLAT_CPLD_LPC_REG_WD3_TLEFT_OFFSET: case MLXPLAT_CPLD_LPC_REG_WD3_ACT_OFFSET: case MLXPLAT_CPLD_LPC_REG_PWM1_OFFSET: case MLXPLAT_CPLD_LPC_REG_PWM_CONTROL_OFFSET: @@ -2601,6 +2683,27 @@ static int mlxplat_mlxcpld_verify_bus_topology(int *nr) return 0; } +static int mlxplat_mlxcpld_check_wd_capability(void *regmap) +{ + u32 regval; + int i, rc; + + rc = regmap_read(regmap, MLXPLAT_CPLD_LPC_REG_PSU_I2C_CAP_OFFSET, + ®val); + if (rc) + return rc; + + if (!(regval & ~MLXPLAT_CPLD_WD_CPBLTY_MASK)) { + for (i = 0; i < ARRAY_SIZE(mlxplat_mlxcpld_wd_set_type3); i++) { + if (mlxplat_wd_data[i]) + mlxplat_wd_data[i] = + &mlxplat_mlxcpld_wd_set_type3[i]; + } + } + + return 0; +} + static int __init mlxplat_init(void) { struct mlxplat_priv *priv; @@ -2733,6 +2836,9 @@ static int __init mlxplat_init(void) } /* Add WD drivers. */ + err = mlxplat_mlxcpld_check_wd_capability(priv->regmap); + if (err) + goto fail_platform_wd_register; for (j = 0; j < MLXPLAT_CPLD_WD_MAX_DEVS; j++) { if (mlxplat_wd_data[j]) { mlxplat_wd_data[j]->regmap = priv->regmap; From patchwork Mon May 4 14:14:26 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Shych X-Patchwork-Id: 11526255 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 9FEB71986 for ; Mon, 4 May 2020 14:14:39 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 91B7E20757 for ; Mon, 4 May 2020 14:14:39 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728855AbgEDOOj (ORCPT ); Mon, 4 May 2020 10:14:39 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:56391 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728893AbgEDOOj (ORCPT ); Mon, 4 May 2020 10:14:39 -0400 Received: from Internal Mail-Server by MTLPINE2 (envelope-from michaelsh@mellanox.com) with ESMTPS (AES256-SHA encrypted); 4 May 2020 17:14:35 +0300 Received: from r-build-lowlevel.mtr.labs.mlnx. (r-build-lowlevel.mtr.labs.mlnx [10.209.0.190]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id 044EEVtV022784; Mon, 4 May 2020 17:14:35 +0300 From: michaelsh@mellanox.com To: linux@roeck-us.net, wim@linux-watchdog.org, andy@infradead.org, dvhart@infradead.org Cc: linux-watchdog@vger.kernel.org, platform-driver-x86@vger.kernel.org, vadimp@mellanox.com, Michael Shych Subject: [PATCH v4 3/4] watchdog: mlx-wdt: support new watchdog type with longer timeout period Date: Mon, 4 May 2020 17:14:26 +0300 Message-Id: <20200504141427.17685-4-michaelsh@mellanox.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20200504141427.17685-1-michaelsh@mellanox.com> References: <20200504141427.17685-1-michaelsh@mellanox.com> Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org From: Michael Shych New programmable logic device can have watchdog type 3 implementation. It's same as Type 2 with extended maximum timeout period. Maximum timeout is up-to 65535 sec. Type 3 HW watchdog implementation can exist on all Mellanox systems. It is differentiated by WD capability bit. Signed-off-by: Michael Shych Reviewed-by: Vadim Pasternak Acked-by: Guenter Roeck --- v1-v2: Make changes pointed out by Guenter: -Simplify bit operations -Consistency in registers access -Don't check irrelevant return code --- v2-v3 Remove unnecessary cpu_to_le16 and vice versa conversions --- drivers/watchdog/mlx_wdt.c | 73 +++++++++++++++++++++++++++++++++++++++------- 1 file changed, 62 insertions(+), 11 deletions(-) diff --git a/drivers/watchdog/mlx_wdt.c b/drivers/watchdog/mlx_wdt.c index 03b9ac4b99af..54193369e85c 100644 --- a/drivers/watchdog/mlx_wdt.c +++ b/drivers/watchdog/mlx_wdt.c @@ -21,6 +21,7 @@ #define MLXREG_WDT_CLOCK_SCALE 1000 #define MLXREG_WDT_MAX_TIMEOUT_TYPE1 32 #define MLXREG_WDT_MAX_TIMEOUT_TYPE2 255 +#define MLXREG_WDT_MAX_TIMEOUT_TYPE3 65535 #define MLXREG_WDT_MIN_TIMEOUT 1 #define MLXREG_WDT_OPTIONS_BASE (WDIOF_KEEPALIVEPING | WDIOF_MAGICCLOSE | \ WDIOF_SETTIMEOUT) @@ -49,6 +50,7 @@ struct mlxreg_wdt { int tleft_idx; int ping_idx; int reset_idx; + int regmap_val_sz; enum mlxreg_wdt_type wdt_type; }; @@ -111,7 +113,8 @@ static int mlxreg_wdt_set_timeout(struct watchdog_device *wdd, u32 regval, set_time, hw_timeout; int rc; - if (wdt->wdt_type == MLX_WDT_TYPE1) { + switch (wdt->wdt_type) { + case MLX_WDT_TYPE1: rc = regmap_read(wdt->regmap, reg_data->reg, ®val); if (rc) return rc; @@ -120,14 +123,32 @@ static int mlxreg_wdt_set_timeout(struct watchdog_device *wdd, regval = (regval & reg_data->mask) | hw_timeout; /* Rowndown to actual closest number of sec. */ set_time = BIT(hw_timeout) / MLXREG_WDT_CLOCK_SCALE; - } else { + rc = regmap_write(wdt->regmap, reg_data->reg, regval); + break; + case MLX_WDT_TYPE2: + set_time = timeout; + rc = regmap_write(wdt->regmap, reg_data->reg, timeout); + break; + case MLX_WDT_TYPE3: + /* WD_TYPE3 has 2B set time register */ set_time = timeout; - regval = timeout; + if (wdt->regmap_val_sz == 1) { + regval = timeout & 0xff; + rc = regmap_write(wdt->regmap, reg_data->reg, regval); + if (!rc) { + regval = (timeout & 0xff00) >> 8; + rc = regmap_write(wdt->regmap, + reg_data->reg + 1, regval); + } + } else { + rc = regmap_write(wdt->regmap, reg_data->reg, timeout); + } + break; + default: + return -EINVAL; } wdd->timeout = set_time; - rc = regmap_write(wdt->regmap, reg_data->reg, regval); - if (!rc) { /* * Restart watchdog with new timeout period @@ -147,10 +168,25 @@ static unsigned int mlxreg_wdt_get_timeleft(struct watchdog_device *wdd) { struct mlxreg_wdt *wdt = watchdog_get_drvdata(wdd); struct mlxreg_core_data *reg_data = &wdt->pdata->data[wdt->tleft_idx]; - u32 regval; + u32 regval, msb, lsb; int rc; - rc = regmap_read(wdt->regmap, reg_data->reg, ®val); + if (wdt->wdt_type == MLX_WDT_TYPE2) { + rc = regmap_read(wdt->regmap, reg_data->reg, ®val); + } else { + /* WD_TYPE3 has 2 byte timeleft register */ + if (wdt->regmap_val_sz == 1) { + rc = regmap_read(wdt->regmap, reg_data->reg, &lsb); + if (!rc) { + rc = regmap_read(wdt->regmap, + reg_data->reg + 1, &msb); + regval = (msb & 0xff) << 8 | (lsb & 0xff); + } + } else { + rc = regmap_read(wdt->regmap, reg_data->reg, ®val); + } + } + /* Return 0 timeleft in case of failure register read. */ return rc == 0 ? regval : 0; } @@ -212,13 +248,23 @@ static void mlxreg_wdt_config(struct mlxreg_wdt *wdt, wdt->wdd.info = &mlxreg_wdt_aux_info; wdt->wdt_type = pdata->version; - if (wdt->wdt_type == MLX_WDT_TYPE2) { - wdt->wdd.ops = &mlxreg_wdt_ops_type2; - wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE2; - } else { + switch (wdt->wdt_type) { + case MLX_WDT_TYPE1: wdt->wdd.ops = &mlxreg_wdt_ops_type1; wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE1; + break; + case MLX_WDT_TYPE2: + wdt->wdd.ops = &mlxreg_wdt_ops_type2; + wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE2; + break; + case MLX_WDT_TYPE3: + wdt->wdd.ops = &mlxreg_wdt_ops_type2; + wdt->wdd.max_timeout = MLXREG_WDT_MAX_TIMEOUT_TYPE3; + break; + default: + break; } + wdt->wdd.min_timeout = MLXREG_WDT_MIN_TIMEOUT; } @@ -249,6 +295,11 @@ static int mlxreg_wdt_probe(struct platform_device *pdev) wdt->wdd.parent = dev; wdt->regmap = pdata->regmap; + rc = regmap_get_val_bytes(wdt->regmap); + if (rc < 0) + return -EINVAL; + + wdt->regmap_val_sz = rc; mlxreg_wdt_config(wdt, pdata); if ((pdata->features & MLXREG_CORE_WD_FEATURE_NOWAYOUT)) From patchwork Mon May 4 14:14:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Shych X-Patchwork-Id: 11526259 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 0F441913 for ; Mon, 4 May 2020 14:14:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ECA582075B for ; Mon, 4 May 2020 14:14:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728943AbgEDOOn (ORCPT ); Mon, 4 May 2020 10:14:43 -0400 Received: from mail-il-dmz.mellanox.com ([193.47.165.129]:58151 "EHLO mellanox.co.il" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1728762AbgEDOOn (ORCPT ); Mon, 4 May 2020 10:14:43 -0400 Received: from Internal Mail-Server by MTLPINE1 (envelope-from michaelsh@mellanox.com) with ESMTPS (AES256-SHA encrypted); 4 May 2020 17:14:36 +0300 Received: from r-build-lowlevel.mtr.labs.mlnx. (r-build-lowlevel.mtr.labs.mlnx [10.209.0.190]) by labmailer.mlnx (8.13.8/8.13.8) with ESMTP id 044EEVtW022784; Mon, 4 May 2020 17:14:36 +0300 From: michaelsh@mellanox.com To: linux@roeck-us.net, wim@linux-watchdog.org, andy@infradead.org, dvhart@infradead.org Cc: linux-watchdog@vger.kernel.org, platform-driver-x86@vger.kernel.org, vadimp@mellanox.com, Michael Shych Subject: [PATCH v4 4/4] docs: watchdog: mlx-wdt: Add description of new watchdog type 3 Date: Mon, 4 May 2020 17:14:27 +0300 Message-Id: <20200504141427.17685-5-michaelsh@mellanox.com> X-Mailer: git-send-email 2.11.0 In-Reply-To: <20200504141427.17685-1-michaelsh@mellanox.com> References: <20200504141427.17685-1-michaelsh@mellanox.com> Sender: linux-watchdog-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org From: Michael Shych Add documentation with details of new type of Mellanox watchdog driver. Signed-off-by: Michael Shych Reviewed-by: Vadim Pasternak Acked-by: Guenter Roeck --- v1-v2: Add explanation about device registers order --- v2-v3: Remove note about cpu_to_le16 and vice versa conversion --- Documentation/watchdog/mlx-wdt.rst | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/Documentation/watchdog/mlx-wdt.rst b/Documentation/watchdog/mlx-wdt.rst index bf5bafac47f0..35e690dea9db 100644 --- a/Documentation/watchdog/mlx-wdt.rst +++ b/Documentation/watchdog/mlx-wdt.rst @@ -24,10 +24,19 @@ Type 2: Maximum timeout is 255 sec. Get time-left is supported. +Type 3: + Same as Type 2 with extended maximum timeout period. + Maximum timeout is 65535 sec. + Type 1 HW watchdog implementation exist in old systems and all new systems have type 2 HW watchdog. Two types of HW implementation have also different register map. +Type 3 HW watchdog implementation can exist on all Mellanox systems +with new programmer logic device. +It's differentiated by WD capability bit. +Old systems still have only one main watchdog. + Mellanox system can have 2 watchdogs: main and auxiliary. Main and auxiliary watchdog devices can be enabled together on the same system. @@ -54,3 +63,4 @@ The driver checks during initialization if the previous system reset was done by the watchdog. If yes, it makes a notification about this event. Access to HW registers is performed through a generic regmap interface. +Programmable logic device registers have little-endian order.