From patchwork Tue May 26 15:41:17 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 11570741 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 E661460D for ; Tue, 26 May 2020 15:42:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D7D7820663 for ; Tue, 26 May 2020 15:42:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729989AbgEZPle (ORCPT ); Tue, 26 May 2020 11:41:34 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:58516 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729212AbgEZPle (ORCPT ); Tue, 26 May 2020 11:41:34 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id 46050803086B; Tue, 26 May 2020 15:41:31 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id DHI_9ZiuWhHA; Tue, 26 May 2020 18:41:30 +0300 (MSK) From: Serge Semin To: Wim Van Sebroeck , Guenter Roeck , Rob Herring CC: Serge Semin , Serge Semin , Rob Herring , Alexey Malahov , Thomas Bogendoerfer , Arnd Bergmann , , , , Subject: [PATCH v3 1/7] dt-bindings: watchdog: Convert DW WDT binding to DT schema Date: Tue, 26 May 2020 18:41:17 +0300 Message-ID: <20200526154123.24402-2-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> References: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Modern device tree bindings are supposed to be created as YAML-files in accordance with dt-schema. This commit replaces the DW Watchdog legacy bare text bindings with YAML file. As before the binding states that the corresponding dts node is supposed to have a registers range, a watchdog timer references clock source, optional reset line and pre-timeout interrupt. Signed-off-by: Serge Semin Reviewed-by: Rob Herring Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Arnd Bergmann Cc: linux-mips@vger.kernel.org Reviewed-by: Guenter Roeck --- Changelog v2: - Rearrange SoBs. - Discard BE copyright header. - Replace "additionalProperties: false" with "unevaluatedProperties: false" property. - Discard interrupts property from the required properties list. - Remove a label definition from the binding example. - Move the asynchronous APB3 clock support into a dedicated patch. --- .../devicetree/bindings/watchdog/dw_wdt.txt | 24 --------- .../bindings/watchdog/snps,dw-wdt.yaml | 50 +++++++++++++++++++ 2 files changed, 50 insertions(+), 24 deletions(-) delete mode 100644 Documentation/devicetree/bindings/watchdog/dw_wdt.txt create mode 100644 Documentation/devicetree/bindings/watchdog/snps,dw-wdt.yaml diff --git a/Documentation/devicetree/bindings/watchdog/dw_wdt.txt b/Documentation/devicetree/bindings/watchdog/dw_wdt.txt deleted file mode 100644 index eb0914420c7c..000000000000 --- a/Documentation/devicetree/bindings/watchdog/dw_wdt.txt +++ /dev/null @@ -1,24 +0,0 @@ -Synopsys Designware Watchdog Timer - -Required Properties: - -- compatible : Should contain "snps,dw-wdt" -- reg : Base address and size of the watchdog timer registers. -- clocks : phandle + clock-specifier for the clock that drives the - watchdog timer. - -Optional Properties: - -- interrupts : The interrupt used for the watchdog timeout warning. -- resets : phandle pointing to the system reset controller with - line index for the watchdog. - -Example: - - watchdog0: wd@ffd02000 { - compatible = "snps,dw-wdt"; - reg = <0xffd02000 0x1000>; - interrupts = <0 171 4>; - clocks = <&per_base_clk>; - resets = <&rst WDT0_RESET>; - }; diff --git a/Documentation/devicetree/bindings/watchdog/snps,dw-wdt.yaml b/Documentation/devicetree/bindings/watchdog/snps,dw-wdt.yaml new file mode 100644 index 000000000000..4f6944756ab4 --- /dev/null +++ b/Documentation/devicetree/bindings/watchdog/snps,dw-wdt.yaml @@ -0,0 +1,50 @@ +# SPDX-License-Identifier: GPL-2.0-only +%YAML 1.2 +--- +$id: http://devicetree.org/schemas/watchdog/snps,dw-wdt.yaml# +$schema: http://devicetree.org/meta-schemas/core.yaml# + +title: Synopsys Designware Watchdog Timer + +allOf: + - $ref: "watchdog.yaml#" + +maintainers: + - Jamie Iles + +properties: + compatible: + const: snps,dw-wdt + + reg: + maxItems: 1 + + interrupts: + description: DW Watchdog pre-timeout interrupt + maxItems: 1 + + clocks: + items: + - description: Watchdog timer reference clock + + resets: + description: Phandle to the DW Watchdog reset lane + maxItems: 1 + +unevaluatedProperties: false + +required: + - compatible + - reg + - clocks + +examples: + - | + watchdog@ffd02000 { + compatible = "snps,dw-wdt"; + reg = <0xffd02000 0x1000>; + interrupts = <0 171 4>; + clocks = <&per_base_clk>; + resets = <&wdt_rst>; + }; +... From patchwork Tue May 26 15:41:18 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 11570715 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 AE7AF60D for ; Tue, 26 May 2020 15:41:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 94244207FB for ; Tue, 26 May 2020 15:41:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729652AbgEZPle (ORCPT ); Tue, 26 May 2020 11:41:34 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:58532 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729309AbgEZPle (ORCPT ); Tue, 26 May 2020 11:41:34 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id 5D814803086E; Tue, 26 May 2020 15:41:31 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id PIJ20QByC4TS; Tue, 26 May 2020 18:41:30 +0300 (MSK) From: Serge Semin To: Wim Van Sebroeck , Guenter Roeck , Rob Herring CC: Serge Semin , Serge Semin , Rob Herring , Alexey Malahov , Thomas Bogendoerfer , Arnd Bergmann , , , , Subject: [PATCH v3 2/7] dt-bindings: watchdog: dw-wdt: Support devices with asynch clocks Date: Tue, 26 May 2020 18:41:18 +0300 Message-ID: <20200526154123.24402-3-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> References: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org DW Watchdog IP core can be synthesised with asynchronous timer/APB clocks support (WDT_ASYNC_CLK_MODE_ENABLE == 1). In this case separate clock signals are supposed to be used to feed watchdog timer and APB interface of the device. Let's update the DW Watchdog DT node schema so it would support the optional APB3 bus clock specified along with the mandatory watchdog timer reference clock. Signed-off-by: Serge Semin Reviewed-by: Rob Herring Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Arnd Bergmann Cc: linux-mips@vger.kernel.org Reviewed-by: Guenter Roeck --- Changelog v2: - It's a new patch unpinned from the previous one. --- .../devicetree/bindings/watchdog/snps,dw-wdt.yaml | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/Documentation/devicetree/bindings/watchdog/snps,dw-wdt.yaml b/Documentation/devicetree/bindings/watchdog/snps,dw-wdt.yaml index 4f6944756ab4..5bf6dc6377f3 100644 --- a/Documentation/devicetree/bindings/watchdog/snps,dw-wdt.yaml +++ b/Documentation/devicetree/bindings/watchdog/snps,dw-wdt.yaml @@ -24,8 +24,16 @@ properties: maxItems: 1 clocks: + minItems: 1 items: - description: Watchdog timer reference clock + - description: APB3 interface clock + + clock-names: + minItems: 1 + items: + - const: tclk + - const: pclk resets: description: Phandle to the DW Watchdog reset lane From patchwork Tue May 26 15:41:19 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 11570735 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 6338560D for ; Tue, 26 May 2020 15:42:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 54FCA206D5 for ; Tue, 26 May 2020 15:42:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730166AbgEZPlg (ORCPT ); Tue, 26 May 2020 11:41:36 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:58552 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729478AbgEZPlf (ORCPT ); Tue, 26 May 2020 11:41:35 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id 10BC98030869; Tue, 26 May 2020 15:41:32 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 6TNrqTLnLn94; Tue, 26 May 2020 18:41:31 +0300 (MSK) From: Serge Semin To: Wim Van Sebroeck , Guenter Roeck , Rob Herring CC: Serge Semin , Serge Semin , Rob Herring , Alexey Malahov , Thomas Bogendoerfer , Arnd Bergmann , , , , Subject: [PATCH v3 3/7] dt-bindings: watchdog: dw-wdt: Add watchdog TOPs array property Date: Tue, 26 May 2020 18:41:19 +0300 Message-ID: <20200526154123.24402-4-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> References: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org In case if DW Watchdog IP core is built with WDT_USE_FIX_TOP == false, a custom timeout periods are used to preset the timer counter. In this case that periods should be specified in a new "snps,watchdog-tops" property of the DW watchdog dts node. Signed-off-by: Serge Semin Reviewed-by: Rob Herring Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Arnd Bergmann Cc: linux-mips@vger.kernel.org Reviewed-by: Guenter Roeck --- Changelog v2: - Rearrange SoBs. - Move $ref to the root level of the "snps,watchdog-tops" property so does the constraints. - Add default TOP values array. - Discard the label definition from the new bindings example. Changelog v3: - Remove items property and move the minItems and maxItems constraints to the root level of the snps,watchdog-tops property. --- .../bindings/watchdog/snps,dw-wdt.yaml | 32 +++++++++++++++++++ 1 file changed, 32 insertions(+) diff --git a/Documentation/devicetree/bindings/watchdog/snps,dw-wdt.yaml b/Documentation/devicetree/bindings/watchdog/snps,dw-wdt.yaml index 5bf6dc6377f3..d9fc7bb851b1 100644 --- a/Documentation/devicetree/bindings/watchdog/snps,dw-wdt.yaml +++ b/Documentation/devicetree/bindings/watchdog/snps,dw-wdt.yaml @@ -39,6 +39,23 @@ properties: description: Phandle to the DW Watchdog reset lane maxItems: 1 + snps,watchdog-tops: + $ref: /schemas/types.yaml#/definitions/uint32-array + description: | + DW APB Watchdog custom timer intervals - Timeout Period ranges (TOPs). + Each TOP is a number loaded into the watchdog counter at the moment of + the timer restart. The counter decrementing happens each tick of the + reference clock. Therefore the TOPs array is equivalent to an array of + the timer expiration intervals supported by the DW APB Watchdog. Note + DW APB Watchdog IP-core might be synthesized with fixed TOP values, + in which case this property is unnecessary with default TOPs utilized. + default: [0x0001000 0x0002000 0x0004000 0x0008000 + 0x0010000 0x0020000 0x0040000 0x0080000 + 0x0100000 0x0200000 0x0400000 0x0800000 + 0x1000000 0x2000000 0x4000000 0x8000000] + minItems: 16 + maxItems: 16 + unevaluatedProperties: false required: @@ -55,4 +72,19 @@ examples: clocks = <&per_base_clk>; resets = <&wdt_rst>; }; + + - | + watchdog@ffd02000 { + compatible = "snps,dw-wdt"; + reg = <0xffd02000 0x1000>; + interrupts = <0 171 4>; + clocks = <&per_base_clk>; + clock-names = "tclk"; + snps,watchdog-tops = <0x000000FF 0x000001FF 0x000003FF + 0x000007FF 0x0000FFFF 0x0001FFFF + 0x0003FFFF 0x0007FFFF 0x000FFFFF + 0x001FFFFF 0x003FFFFF 0x007FFFFF + 0x00FFFFFF 0x01FFFFFF 0x03FFFFFF + 0x07FFFFFF>; + }; ... From patchwork Tue May 26 15:41:20 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 11570733 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 A57B1166C for ; Tue, 26 May 2020 15:42:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9819F208B3 for ; Tue, 26 May 2020 15:42:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727898AbgEZPly (ORCPT ); Tue, 26 May 2020 11:41:54 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:58566 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729481AbgEZPlg (ORCPT ); Tue, 26 May 2020 11:41:36 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id 1786C803086F; Tue, 26 May 2020 15:41:33 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id P3liY5ESx7ym; Tue, 26 May 2020 18:41:32 +0300 (MSK) From: Serge Semin To: Wim Van Sebroeck , Guenter Roeck CC: Serge Semin , Serge Semin , Alexey Malahov , Thomas Bogendoerfer , Arnd Bergmann , Rob Herring , , , , Subject: [PATCH v3 4/7] watchdog: dw_wdt: Support devices with non-fixed TOP values Date: Tue, 26 May 2020 18:41:20 +0300 Message-ID: <20200526154123.24402-5-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> References: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org In case if the DW Watchdog IP core is synthesised with WDT_USE_FIX_TOP == false, the TOP interval indexes make the device to load a custom periods to the counter. These periods are hardwired at the IP synthesis stage and can be within [2^8, 2^(WDT_CNT_WIDTH - 1)]. Alas their values can't be detected at runtime and must be somehow supplied to the driver so one could properly determine the watchdog timeout intervals. For this purpose we suggest to have a vendor- specific dts property "snps,watchdog-tops" utilized, which would provide an array of sixteen counter values. At device probe stage they will be used to initialize the watchdog device timeouts determined from the array values and current clocks source rate. In order to have custom TOP values supported the driver must be altered in the following way. First of all the fixed-top values ready-to-use array must be determined for compatibility with currently supported devices, which were synthesised with WDT_USE_FIX_TOP == true. It will be used if either fixed TOP feature is detected being enabled or no custom TOPs are fetched from the device dt node. Secondly at the probe stage we must initialize an array of the watchdog timeouts corresponding to the detected TOPs list and the reference clock rate. For generality the procedure of initialization is designed in a way to support the TOPs array with no limitations on the items order or value. Finally the watchdog period search methods should be altered to support the new timeouts data structure. Signed-off-by: Serge Semin Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Arnd Bergmann Cc: Rob Herring Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Reviewed-by: Guenter Roeck --- Changelog v2: - Rearrange SoBs. - Add "ms" suffix to the methods returning msec and convert the methods with no "ms" suffix to return a timeout in sec. - Make sure minimum timeout is at least 1 sec. - Refactor the timeouts calculation procedure to retain the timeouts in the ascending order. - Make sure there is no integer overflow in milliseconds calculation. It is saved in a dedicated uint field of the timeout structure. --- drivers/watchdog/dw_wdt.c | 191 +++++++++++++++++++++++++++++++++----- 1 file changed, 167 insertions(+), 24 deletions(-) diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c index fba21de2bbad..693c0d1fd796 100644 --- a/drivers/watchdog/dw_wdt.c +++ b/drivers/watchdog/dw_wdt.c @@ -13,6 +13,8 @@ */ #include +#include +#include #include #include #include @@ -34,21 +36,40 @@ #define WDOG_CURRENT_COUNT_REG_OFFSET 0x08 #define WDOG_COUNTER_RESTART_REG_OFFSET 0x0c #define WDOG_COUNTER_RESTART_KICK_VALUE 0x76 +#define WDOG_COMP_PARAMS_1_REG_OFFSET 0xf4 +#define WDOG_COMP_PARAMS_1_USE_FIX_TOP BIT(6) -/* The maximum TOP (timeout period) value that can be set in the watchdog. */ -#define DW_WDT_MAX_TOP 15 +/* There are sixteen TOPs (timeout periods) that can be set in the watchdog. */ +#define DW_WDT_NUM_TOPS 16 +#define DW_WDT_FIX_TOP(_idx) (1U << (16 + _idx)) #define DW_WDT_DEFAULT_SECONDS 30 +static const u32 dw_wdt_fix_tops[DW_WDT_NUM_TOPS] = { + DW_WDT_FIX_TOP(0), DW_WDT_FIX_TOP(1), DW_WDT_FIX_TOP(2), + DW_WDT_FIX_TOP(3), DW_WDT_FIX_TOP(4), DW_WDT_FIX_TOP(5), + DW_WDT_FIX_TOP(6), DW_WDT_FIX_TOP(7), DW_WDT_FIX_TOP(8), + DW_WDT_FIX_TOP(9), DW_WDT_FIX_TOP(10), DW_WDT_FIX_TOP(11), + DW_WDT_FIX_TOP(12), DW_WDT_FIX_TOP(13), DW_WDT_FIX_TOP(14), + DW_WDT_FIX_TOP(15) +}; + static bool nowayout = WATCHDOG_NOWAYOUT; module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); +struct dw_wdt_timeout { + u32 top_val; + unsigned int sec; + unsigned int msec; +}; + struct dw_wdt { void __iomem *regs; struct clk *clk; unsigned long rate; + struct dw_wdt_timeout timeouts[DW_WDT_NUM_TOPS]; struct watchdog_device wdd; struct reset_control *rst; /* Save/restore */ @@ -64,20 +85,66 @@ static inline int dw_wdt_is_enabled(struct dw_wdt *dw_wdt) WDOG_CONTROL_REG_WDT_EN_MASK; } -static inline int dw_wdt_top_in_seconds(struct dw_wdt *dw_wdt, unsigned top) +static unsigned int dw_wdt_find_best_top(struct dw_wdt *dw_wdt, + unsigned int timeout, u32 *top_val) { + int idx; + /* - * There are 16 possible timeout values in 0..15 where the number of - * cycles is 2 ^ (16 + i) and the watchdog counts down. + * Find a TOP with timeout greater or equal to the requested number. + * Note we'll select a TOP with maximum timeout if the requested + * timeout couldn't be reached. */ - return (1U << (16 + top)) / dw_wdt->rate; + for (idx = 0; idx < DW_WDT_NUM_TOPS; ++idx) { + if (dw_wdt->timeouts[idx].sec >= timeout) + break; + } + + if (idx == DW_WDT_NUM_TOPS) + --idx; + + *top_val = dw_wdt->timeouts[idx].top_val; + + return dw_wdt->timeouts[idx].sec; } -static int dw_wdt_get_top(struct dw_wdt *dw_wdt) +static unsigned int dw_wdt_get_min_timeout(struct dw_wdt *dw_wdt) { - int top = readl(dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET) & 0xF; + int idx; + + /* + * We'll find a timeout greater or equal to one second anyway because + * the driver probe would have failed if there was none. + */ + for (idx = 0; idx < DW_WDT_NUM_TOPS; ++idx) { + if (dw_wdt->timeouts[idx].sec) + break; + } - return dw_wdt_top_in_seconds(dw_wdt, top); + return dw_wdt->timeouts[idx].sec; +} + +static unsigned int dw_wdt_get_max_timeout_ms(struct dw_wdt *dw_wdt) +{ + struct dw_wdt_timeout *timeout = &dw_wdt->timeouts[DW_WDT_NUM_TOPS - 1]; + u64 msec; + + msec = (u64)timeout->sec * MSEC_PER_SEC + timeout->msec; + + return msec < UINT_MAX ? msec : UINT_MAX; +} + +static unsigned int dw_wdt_get_timeout(struct dw_wdt *dw_wdt) +{ + int top_val = readl(dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET) & 0xF; + int idx; + + for (idx = 0; idx < DW_WDT_NUM_TOPS; ++idx) { + if (dw_wdt->timeouts[idx].top_val == top_val) + break; + } + + return dw_wdt->timeouts[idx].sec; } static int dw_wdt_ping(struct watchdog_device *wdd) @@ -93,17 +160,10 @@ static int dw_wdt_ping(struct watchdog_device *wdd) static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s) { struct dw_wdt *dw_wdt = to_dw_wdt(wdd); - int i, top_val = DW_WDT_MAX_TOP; + unsigned int timeout; + u32 top_val; - /* - * Iterate over the timeout values until we find the closest match. We - * always look for >=. - */ - for (i = 0; i <= DW_WDT_MAX_TOP; ++i) - if (dw_wdt_top_in_seconds(dw_wdt, i) >= top_s) { - top_val = i; - break; - } + timeout = dw_wdt_find_best_top(dw_wdt, top_s, &top_val); /* * Set the new value in the watchdog. Some versions of dw_wdt @@ -120,7 +180,7 @@ static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s) * wdd->max_hw_heartbeat_ms */ if (top_s * 1000 <= wdd->max_hw_heartbeat_ms) - wdd->timeout = dw_wdt_top_in_seconds(dw_wdt, top_val); + wdd->timeout = timeout; else wdd->timeout = top_s; @@ -238,6 +298,86 @@ static int dw_wdt_resume(struct device *dev) static SIMPLE_DEV_PM_OPS(dw_wdt_pm_ops, dw_wdt_suspend, dw_wdt_resume); +/* + * In case if DW WDT IP core is synthesized with fixed TOP feature disabled the + * TOPs array can be arbitrary ordered with nearly any sixteen uint numbers + * depending on the system engineer imagination. The next method handles the + * passed TOPs array to pre-calculate the effective timeouts and to sort the + * TOP items out in the ascending order with respect to the timeouts. + */ + +static void dw_wdt_handle_tops(struct dw_wdt *dw_wdt, const u32 *tops) +{ + struct dw_wdt_timeout tout, *dst; + int val, tidx; + u64 msec; + + /* + * We walk over the passed TOPs array and calculate corresponding + * timeouts in seconds and milliseconds. The milliseconds granularity + * is needed to distinguish the TOPs with very close timeouts and to + * set the watchdog max heartbeat setting further. + */ + for (val = 0; val < DW_WDT_NUM_TOPS; ++val) { + tout.top_val = val; + tout.sec = tops[val] / dw_wdt->rate; + msec = (u64)tops[val] * MSEC_PER_SEC; + do_div(msec, dw_wdt->rate); + tout.msec = msec - ((u64)tout.sec * MSEC_PER_SEC); + + /* + * Find a suitable place for the current TOP in the timeouts + * array so that the list is remained in the ascending order. + */ + for (tidx = 0; tidx < val; ++tidx) { + dst = &dw_wdt->timeouts[tidx]; + if (tout.sec > dst->sec || (tout.sec == dst->sec && + tout.msec >= dst->msec)) + continue; + else + swap(*dst, tout); + } + + dw_wdt->timeouts[val] = tout; + } +} + +static int dw_wdt_init_timeouts(struct dw_wdt *dw_wdt, struct device *dev) +{ + u32 data, of_tops[DW_WDT_NUM_TOPS]; + const u32 *tops; + int ret; + + /* + * Retrieve custom or fixed counter values depending on the + * WDT_USE_FIX_TOP flag found in the component specific parameters + * #1 register. + */ + data = readl(dw_wdt->regs + WDOG_COMP_PARAMS_1_REG_OFFSET); + if (data & WDOG_COMP_PARAMS_1_USE_FIX_TOP) { + tops = dw_wdt_fix_tops; + } else { + ret = of_property_read_variable_u32_array(dev_of_node(dev), + "snps,watchdog-tops", of_tops, DW_WDT_NUM_TOPS, + DW_WDT_NUM_TOPS); + if (ret < 0) { + dev_warn(dev, "No valid TOPs array specified\n"); + tops = dw_wdt_fix_tops; + } else { + tops = of_tops; + } + } + + /* Convert the specified TOPs into an array of watchdog timeouts. */ + dw_wdt_handle_tops(dw_wdt, tops); + if (!dw_wdt->timeouts[DW_WDT_NUM_TOPS - 1].sec) { + dev_err(dev, "No any valid TOP detected\n"); + return -EINVAL; + } + + return 0; +} + static int dw_wdt_drv_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -275,12 +415,15 @@ static int dw_wdt_drv_probe(struct platform_device *pdev) reset_control_deassert(dw_wdt->rst); + ret = dw_wdt_init_timeouts(dw_wdt, dev); + if (ret) + goto out_disable_clk; + wdd = &dw_wdt->wdd; wdd->info = &dw_wdt_ident; wdd->ops = &dw_wdt_ops; - wdd->min_timeout = 1; - wdd->max_hw_heartbeat_ms = - dw_wdt_top_in_seconds(dw_wdt, DW_WDT_MAX_TOP) * 1000; + wdd->min_timeout = dw_wdt_get_min_timeout(dw_wdt); + wdd->max_hw_heartbeat_ms = dw_wdt_get_max_timeout_ms(dw_wdt); wdd->parent = dev; watchdog_set_drvdata(wdd, dw_wdt); @@ -293,7 +436,7 @@ static int dw_wdt_drv_probe(struct platform_device *pdev) * devicetree. */ if (dw_wdt_is_enabled(dw_wdt)) { - wdd->timeout = dw_wdt_get_top(dw_wdt); + wdd->timeout = dw_wdt_get_timeout(dw_wdt); set_bit(WDOG_HW_RUNNING, &wdd->status); } else { wdd->timeout = DW_WDT_DEFAULT_SECONDS; From patchwork Tue May 26 15:41:21 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 11570727 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 2D93D60D for ; Tue, 26 May 2020 15:41:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1F593206D5 for ; Tue, 26 May 2020 15:41:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729519AbgEZPlj (ORCPT ); Tue, 26 May 2020 11:41:39 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:58594 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729309AbgEZPli (ORCPT ); Tue, 26 May 2020 11:41:38 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id 73C28803086D; Tue, 26 May 2020 15:41:33 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id obwMDeLfvhXk; Tue, 26 May 2020 18:41:32 +0300 (MSK) From: Serge Semin To: Wim Van Sebroeck , Guenter Roeck CC: Serge Semin , Serge Semin , Alexey Malahov , Thomas Bogendoerfer , Arnd Bergmann , Rob Herring , , , , Subject: [PATCH v3 5/7] watchdog: dw_wdt: Support devices with asynch clocks Date: Tue, 26 May 2020 18:41:21 +0300 Message-ID: <20200526154123.24402-6-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> References: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org DW Watchdog IP core can be synthesised with asynchronous timer/APB clocks support (WDT_ASYNC_CLK_MODE_ENABLE == 1). In this case separate clock signals are supposed to be used to feed watchdog timer and APB interface of the device. Currently the driver supports the synchronous mode only. Since there is no way to determine which mode was actually activated for device from its registers, we have to rely on the platform device configuration data. If optional "pclk" clock source is supplied, we consider the device working in asynchronous mode, otherwise the driver falls back to the synchronous configuration. Signed-off-by: Serge Semin Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Arnd Bergmann Cc: Rob Herring Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Reviewed-by: Guenter Roeck --- Changelog v2: - Rearrange SoBs. --- drivers/watchdog/dw_wdt.c | 48 +++++++++++++++++++++++++++++++++++---- 1 file changed, 43 insertions(+), 5 deletions(-) diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c index 693c0d1fd796..efbc36872670 100644 --- a/drivers/watchdog/dw_wdt.c +++ b/drivers/watchdog/dw_wdt.c @@ -68,6 +68,7 @@ struct dw_wdt_timeout { struct dw_wdt { void __iomem *regs; struct clk *clk; + struct clk *pclk; unsigned long rate; struct dw_wdt_timeout timeouts[DW_WDT_NUM_TOPS]; struct watchdog_device wdd; @@ -274,6 +275,7 @@ static int dw_wdt_suspend(struct device *dev) dw_wdt->control = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET); dw_wdt->timeout = readl(dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET); + clk_disable_unprepare(dw_wdt->pclk); clk_disable_unprepare(dw_wdt->clk); return 0; @@ -287,6 +289,12 @@ static int dw_wdt_resume(struct device *dev) if (err) return err; + err = clk_prepare_enable(dw_wdt->pclk); + if (err) { + clk_disable_unprepare(dw_wdt->clk); + return err; + } + writel(dw_wdt->timeout, dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET); writel(dw_wdt->control, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET); @@ -393,9 +401,18 @@ static int dw_wdt_drv_probe(struct platform_device *pdev) if (IS_ERR(dw_wdt->regs)) return PTR_ERR(dw_wdt->regs); - dw_wdt->clk = devm_clk_get(dev, NULL); - if (IS_ERR(dw_wdt->clk)) - return PTR_ERR(dw_wdt->clk); + /* + * Try to request the watchdog dedicated timer clock source. It must + * be supplied if asynchronous mode is enabled. Otherwise fallback + * to the common timer/bus clocks configuration, in which the very + * first found clock supply both timer and APB signals. + */ + dw_wdt->clk = devm_clk_get(dev, "tclk"); + if (IS_ERR(dw_wdt->clk)) { + dw_wdt->clk = devm_clk_get(dev, NULL); + if (IS_ERR(dw_wdt->clk)) + return PTR_ERR(dw_wdt->clk); + } ret = clk_prepare_enable(dw_wdt->clk); if (ret) @@ -407,10 +424,27 @@ static int dw_wdt_drv_probe(struct platform_device *pdev) goto out_disable_clk; } + /* + * Request APB clock if device is configured with async clocks mode. + * In this case both tclk and pclk clocks are supposed to be specified. + * Alas we can't know for sure whether async mode was really activated, + * so the pclk phandle reference is left optional. If it couldn't be + * found we consider the device configured in synchronous clocks mode. + */ + dw_wdt->pclk = devm_clk_get_optional(dev, "pclk"); + if (IS_ERR(dw_wdt->pclk)) { + ret = PTR_ERR(dw_wdt->pclk); + goto out_disable_clk; + } + + ret = clk_prepare_enable(dw_wdt->pclk); + if (ret) + goto out_disable_clk; + dw_wdt->rst = devm_reset_control_get_optional_shared(&pdev->dev, NULL); if (IS_ERR(dw_wdt->rst)) { ret = PTR_ERR(dw_wdt->rst); - goto out_disable_clk; + goto out_disable_pclk; } reset_control_deassert(dw_wdt->rst); @@ -449,10 +483,13 @@ static int dw_wdt_drv_probe(struct platform_device *pdev) ret = watchdog_register_device(wdd); if (ret) - goto out_disable_clk; + goto out_disable_pclk; return 0; +out_disable_pclk: + clk_disable_unprepare(dw_wdt->pclk); + out_disable_clk: clk_disable_unprepare(dw_wdt->clk); return ret; @@ -464,6 +501,7 @@ static int dw_wdt_drv_remove(struct platform_device *pdev) watchdog_unregister_device(&dw_wdt->wdd); reset_control_assert(dw_wdt->rst); + clk_disable_unprepare(dw_wdt->pclk); clk_disable_unprepare(dw_wdt->clk); return 0; From patchwork Tue May 26 15:41:22 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 11570723 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 1695C60D for ; Tue, 26 May 2020 15:41:48 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 07998206D5 for ; Tue, 26 May 2020 15:41:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729652AbgEZPlq (ORCPT ); Tue, 26 May 2020 11:41:46 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:58614 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729436AbgEZPlo (ORCPT ); Tue, 26 May 2020 11:41:44 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id 939278030875; Tue, 26 May 2020 15:41:37 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id sevAE6JIOsEL; Tue, 26 May 2020 18:41:33 +0300 (MSK) From: Serge Semin To: Wim Van Sebroeck , Guenter Roeck CC: Serge Semin , Serge Semin , Alexey Malahov , Thomas Bogendoerfer , Arnd Bergmann , Rob Herring , , , , Subject: [PATCH v3 6/7] watchdog: dw_wdt: Add pre-timeouts support Date: Tue, 26 May 2020 18:41:22 +0300 Message-ID: <20200526154123.24402-7-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> References: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org DW Watchdog can rise an interrupt in case if IRQ request mode is enabled and timer reaches the zero value. In this case the IRQ lane is left pending until either the next watchdog kick event (watchdog restart) or until the WDT_EOI register is read or the device/system reset. This interface can be used to implement the pre-timeout functionality optionally provided by the Linux kernel watchdog devices. IRQ mode provides a two stages timeout interface. It means the IRQ is raised when the counter reaches zero, while the system reset occurs only after subsequent timeout if the timer restart is not performed. Due to this peculiarity the pre-timeout value is actually set to the achieved hardware timeout, while the real watchdog timeout is considered to be twice as much of it. This applies a significant limitation on the pre-timeout values, so current implementation supports either zero value, which disables the pre-timeout events, or non-zero values, which imply the pre-timeout to be at least half of the current watchdog timeout. Note that we ask the interrupt controller to detect the rising-edge pre-timeout interrupts to prevent the high-level-IRQs flood, since if the pre-timeout happens, the IRQ lane will be left pending until it's cleared by the timer restart. Signed-off-by: Serge Semin Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Arnd Bergmann Cc: Rob Herring Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Reviewed-by: Guenter Roeck --- Changelog v2: - Rearrange SoBs. - Make the Pre-timeout IRQ being optionally supported. --- drivers/watchdog/dw_wdt.c | 138 +++++++++++++++++++++++++++++++++++--- 1 file changed, 130 insertions(+), 8 deletions(-) diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c index efbc36872670..3cd7c485cd70 100644 --- a/drivers/watchdog/dw_wdt.c +++ b/drivers/watchdog/dw_wdt.c @@ -22,6 +22,7 @@ #include #include #include +#include #include #include #include @@ -36,6 +37,8 @@ #define WDOG_CURRENT_COUNT_REG_OFFSET 0x08 #define WDOG_COUNTER_RESTART_REG_OFFSET 0x0c #define WDOG_COUNTER_RESTART_KICK_VALUE 0x76 +#define WDOG_INTERRUPT_STATUS_REG_OFFSET 0x10 +#define WDOG_INTERRUPT_CLEAR_REG_OFFSET 0x14 #define WDOG_COMP_PARAMS_1_REG_OFFSET 0xf4 #define WDOG_COMP_PARAMS_1_USE_FIX_TOP BIT(6) @@ -59,6 +62,11 @@ module_param(nowayout, bool, 0); MODULE_PARM_DESC(nowayout, "Watchdog cannot be stopped once started " "(default=" __MODULE_STRING(WATCHDOG_NOWAYOUT) ")"); +enum dw_wdt_rmod { + DW_WDT_RMOD_RESET = 1, + DW_WDT_RMOD_IRQ = 2 +}; + struct dw_wdt_timeout { u32 top_val; unsigned int sec; @@ -70,6 +78,7 @@ struct dw_wdt { struct clk *clk; struct clk *pclk; unsigned long rate; + enum dw_wdt_rmod rmod; struct dw_wdt_timeout timeouts[DW_WDT_NUM_TOPS]; struct watchdog_device wdd; struct reset_control *rst; @@ -86,6 +95,20 @@ static inline int dw_wdt_is_enabled(struct dw_wdt *dw_wdt) WDOG_CONTROL_REG_WDT_EN_MASK; } +static void dw_wdt_update_mode(struct dw_wdt *dw_wdt, enum dw_wdt_rmod rmod) +{ + u32 val; + + val = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET); + if (rmod == DW_WDT_RMOD_IRQ) + val |= WDOG_CONTROL_REG_RESP_MODE_MASK; + else + val &= ~WDOG_CONTROL_REG_RESP_MODE_MASK; + writel(val, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET); + + dw_wdt->rmod = rmod; +} + static unsigned int dw_wdt_find_best_top(struct dw_wdt *dw_wdt, unsigned int timeout, u32 *top_val) { @@ -145,7 +168,11 @@ static unsigned int dw_wdt_get_timeout(struct dw_wdt *dw_wdt) break; } - return dw_wdt->timeouts[idx].sec; + /* + * In IRQ mode due to the two stages counter, the actual timeout is + * twice greater than the TOP setting. + */ + return dw_wdt->timeouts[idx].sec * dw_wdt->rmod; } static int dw_wdt_ping(struct watchdog_device *wdd) @@ -164,7 +191,20 @@ static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s) unsigned int timeout; u32 top_val; - timeout = dw_wdt_find_best_top(dw_wdt, top_s, &top_val); + /* + * Note IRQ mode being enabled means having a non-zero pre-timeout + * setup. In this case we try to find a TOP as close to the half of the + * requested timeout as possible since DW Watchdog IRQ mode is designed + * in two stages way - first timeout rises the pre-timeout interrupt, + * second timeout performs the system reset. So basically the effective + * watchdog-caused reset happens after two watchdog TOPs elapsed. + */ + timeout = dw_wdt_find_best_top(dw_wdt, DIV_ROUND_UP(top_s, dw_wdt->rmod), + &top_val); + if (dw_wdt->rmod == DW_WDT_RMOD_IRQ) + wdd->pretimeout = timeout; + else + wdd->pretimeout = 0; /* * Set the new value in the watchdog. Some versions of dw_wdt @@ -175,25 +215,47 @@ static int dw_wdt_set_timeout(struct watchdog_device *wdd, unsigned int top_s) writel(top_val | top_val << WDOG_TIMEOUT_RANGE_TOPINIT_SHIFT, dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET); + /* Kick new TOP value into the watchdog counter if activated. */ + if (watchdog_active(wdd)) + dw_wdt_ping(wdd); + /* * In case users set bigger timeout value than HW can support, * kernel(watchdog_dev.c) helps to feed watchdog before * wdd->max_hw_heartbeat_ms */ if (top_s * 1000 <= wdd->max_hw_heartbeat_ms) - wdd->timeout = timeout; + wdd->timeout = timeout * dw_wdt->rmod; else wdd->timeout = top_s; return 0; } +static int dw_wdt_set_pretimeout(struct watchdog_device *wdd, unsigned int req) +{ + struct dw_wdt *dw_wdt = to_dw_wdt(wdd); + + /* + * We ignore actual value of the timeout passed from user-space + * using it as a flag whether the pretimeout functionality is intended + * to be activated. + */ + dw_wdt_update_mode(dw_wdt, req ? DW_WDT_RMOD_IRQ : DW_WDT_RMOD_RESET); + dw_wdt_set_timeout(wdd, wdd->timeout); + + return 0; +} + static void dw_wdt_arm_system_reset(struct dw_wdt *dw_wdt) { u32 val = readl(dw_wdt->regs + WDOG_CONTROL_REG_OFFSET); - /* Disable interrupt mode; always perform system reset. */ - val &= ~WDOG_CONTROL_REG_RESP_MODE_MASK; + /* Disable/enable interrupt mode depending on the RMOD flag. */ + if (dw_wdt->rmod == DW_WDT_RMOD_IRQ) + val |= WDOG_CONTROL_REG_RESP_MODE_MASK; + else + val &= ~WDOG_CONTROL_REG_RESP_MODE_MASK; /* Enable watchdog. */ val |= WDOG_CONTROL_REG_WDT_EN_MASK; writel(val, dw_wdt->regs + WDOG_CONTROL_REG_OFFSET); @@ -231,6 +293,7 @@ static int dw_wdt_restart(struct watchdog_device *wdd, struct dw_wdt *dw_wdt = to_dw_wdt(wdd); writel(0, dw_wdt->regs + WDOG_TIMEOUT_RANGE_REG_OFFSET); + dw_wdt_update_mode(dw_wdt, DW_WDT_RMOD_RESET); if (dw_wdt_is_enabled(dw_wdt)) writel(WDOG_COUNTER_RESTART_KICK_VALUE, dw_wdt->regs + WDOG_COUNTER_RESTART_REG_OFFSET); @@ -246,9 +309,19 @@ static int dw_wdt_restart(struct watchdog_device *wdd, static unsigned int dw_wdt_get_timeleft(struct watchdog_device *wdd) { struct dw_wdt *dw_wdt = to_dw_wdt(wdd); + unsigned int sec; + u32 val; + + val = readl(dw_wdt->regs + WDOG_CURRENT_COUNT_REG_OFFSET); + sec = val / dw_wdt->rate; - return readl(dw_wdt->regs + WDOG_CURRENT_COUNT_REG_OFFSET) / - dw_wdt->rate; + if (dw_wdt->rmod == DW_WDT_RMOD_IRQ) { + val = readl(dw_wdt->regs + WDOG_INTERRUPT_STATUS_REG_OFFSET); + if (!val) + sec += wdd->pretimeout; + } + + return sec; } static const struct watchdog_info dw_wdt_ident = { @@ -257,16 +330,41 @@ static const struct watchdog_info dw_wdt_ident = { .identity = "Synopsys DesignWare Watchdog", }; +static const struct watchdog_info dw_wdt_pt_ident = { + .options = WDIOF_KEEPALIVEPING | WDIOF_SETTIMEOUT | + WDIOF_PRETIMEOUT | WDIOF_MAGICCLOSE, + .identity = "Synopsys DesignWare Watchdog", +}; + static const struct watchdog_ops dw_wdt_ops = { .owner = THIS_MODULE, .start = dw_wdt_start, .stop = dw_wdt_stop, .ping = dw_wdt_ping, .set_timeout = dw_wdt_set_timeout, + .set_pretimeout = dw_wdt_set_pretimeout, .get_timeleft = dw_wdt_get_timeleft, .restart = dw_wdt_restart, }; +static irqreturn_t dw_wdt_irq(int irq, void *devid) +{ + struct dw_wdt *dw_wdt = devid; + u32 val; + + /* + * We don't clear the IRQ status. It's supposed to be done by the + * following ping operations. + */ + val = readl(dw_wdt->regs + WDOG_INTERRUPT_STATUS_REG_OFFSET); + if (!val) + return IRQ_NONE; + + watchdog_notify_pretimeout(&dw_wdt->wdd); + + return IRQ_HANDLED; +} + #ifdef CONFIG_PM_SLEEP static int dw_wdt_suspend(struct device *dev) { @@ -447,6 +545,31 @@ static int dw_wdt_drv_probe(struct platform_device *pdev) goto out_disable_pclk; } + /* Enable normal reset without pre-timeout by default. */ + dw_wdt_update_mode(dw_wdt, DW_WDT_RMOD_RESET); + + /* + * Pre-timeout IRQ is optional, since some hardware may lack support + * of it. Note we must request rising-edge IRQ, since the lane is left + * pending either until the next watchdog kick event or up to the + * system reset. + */ + ret = platform_get_irq_optional(pdev, 0); + if (ret >= 0) { + ret = devm_request_irq(dev, ret, dw_wdt_irq, + IRQF_SHARED | IRQF_TRIGGER_RISING, + pdev->name, dw_wdt); + if (ret) + goto out_disable_pclk; + + dw_wdt->wdd.info = &dw_wdt_pt_ident; + } else { + if (ret == -EPROBE_DEFER) + goto out_disable_pclk; + + dw_wdt->wdd.info = &dw_wdt_ident; + } + reset_control_deassert(dw_wdt->rst); ret = dw_wdt_init_timeouts(dw_wdt, dev); @@ -454,7 +577,6 @@ static int dw_wdt_drv_probe(struct platform_device *pdev) goto out_disable_clk; wdd = &dw_wdt->wdd; - wdd->info = &dw_wdt_ident; wdd->ops = &dw_wdt_ops; wdd->min_timeout = dw_wdt_get_min_timeout(dw_wdt); wdd->max_hw_heartbeat_ms = dw_wdt_get_max_timeout_ms(dw_wdt); From patchwork Tue May 26 15:41:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 11570717 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 54E1B60D for ; Tue, 26 May 2020 15:41:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 47761206D5 for ; Tue, 26 May 2020 15:41:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729631AbgEZPln (ORCPT ); Tue, 26 May 2020 11:41:43 -0400 Received: from mail.baikalelectronics.com ([87.245.175.226]:58606 "EHLO mail.baikalelectronics.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730135AbgEZPlj (ORCPT ); Tue, 26 May 2020 11:41:39 -0400 Received: from localhost (unknown [127.0.0.1]) by mail.baikalelectronics.ru (Postfix) with ESMTP id C3E1E8030878; Tue, 26 May 2020 15:41:34 +0000 (UTC) X-Virus-Scanned: amavisd-new at baikalelectronics.ru Received: from mail.baikalelectronics.ru ([127.0.0.1]) by localhost (mail.baikalelectronics.ru [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id 499XuFg3cxQM; Tue, 26 May 2020 18:41:34 +0300 (MSK) From: Serge Semin To: Wim Van Sebroeck , Guenter Roeck CC: Serge Semin , Serge Semin , Alexey Malahov , Thomas Bogendoerfer , Arnd Bergmann , Rob Herring , , , , Subject: [PATCH v3 7/7] watchdog: dw_wdt: Add DebugFS files Date: Tue, 26 May 2020 18:41:23 +0300 Message-ID: <20200526154123.24402-8-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> References: <20200526154123.24402-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org For the sake of the easier device-driver debug procedure, we added a DebugFS file with the controller registers state. It's available only if kernel is configured with DebugFS support. Signed-off-by: Serge Semin Cc: Alexey Malahov Cc: Thomas Bogendoerfer Cc: Arnd Bergmann Cc: Rob Herring Cc: linux-mips@vger.kernel.org Cc: devicetree@vger.kernel.org Reviewed-by: Guenter Roeck --- Changelog v2: - Rearrange SoBs. - Discard timeout/pretimeout/ping/enable DebugFS nodes. Registers state dump node is only left. --- drivers/watchdog/dw_wdt.c | 68 +++++++++++++++++++++++++++++++++++++++ 1 file changed, 68 insertions(+) diff --git a/drivers/watchdog/dw_wdt.c b/drivers/watchdog/dw_wdt.c index 3cd7c485cd70..012681baaa6d 100644 --- a/drivers/watchdog/dw_wdt.c +++ b/drivers/watchdog/dw_wdt.c @@ -28,6 +28,7 @@ #include #include #include +#include #define WDOG_CONTROL_REG_OFFSET 0x00 #define WDOG_CONTROL_REG_WDT_EN_MASK 0x01 @@ -39,8 +40,14 @@ #define WDOG_COUNTER_RESTART_KICK_VALUE 0x76 #define WDOG_INTERRUPT_STATUS_REG_OFFSET 0x10 #define WDOG_INTERRUPT_CLEAR_REG_OFFSET 0x14 +#define WDOG_COMP_PARAMS_5_REG_OFFSET 0xe4 +#define WDOG_COMP_PARAMS_4_REG_OFFSET 0xe8 +#define WDOG_COMP_PARAMS_3_REG_OFFSET 0xec +#define WDOG_COMP_PARAMS_2_REG_OFFSET 0xf0 #define WDOG_COMP_PARAMS_1_REG_OFFSET 0xf4 #define WDOG_COMP_PARAMS_1_USE_FIX_TOP BIT(6) +#define WDOG_COMP_VERSION_REG_OFFSET 0xf8 +#define WDOG_COMP_TYPE_REG_OFFSET 0xfc /* There are sixteen TOPs (timeout periods) that can be set in the watchdog. */ #define DW_WDT_NUM_TOPS 16 @@ -85,6 +92,10 @@ struct dw_wdt { /* Save/restore */ u32 control; u32 timeout; + +#ifdef CONFIG_DEBUG_FS + struct dentry *dbgfs_dir; +#endif }; #define to_dw_wdt(wdd) container_of(wdd, struct dw_wdt, wdd) @@ -484,6 +495,59 @@ static int dw_wdt_init_timeouts(struct dw_wdt *dw_wdt, struct device *dev) return 0; } +#ifdef CONFIG_DEBUG_FS + +#define DW_WDT_DBGFS_REG(_name, _off) \ +{ \ + .name = _name, \ + .offset = _off \ +} + +static const struct debugfs_reg32 dw_wdt_dbgfs_regs[] = { + DW_WDT_DBGFS_REG("cr", WDOG_CONTROL_REG_OFFSET), + DW_WDT_DBGFS_REG("torr", WDOG_TIMEOUT_RANGE_REG_OFFSET), + DW_WDT_DBGFS_REG("ccvr", WDOG_CURRENT_COUNT_REG_OFFSET), + DW_WDT_DBGFS_REG("crr", WDOG_COUNTER_RESTART_REG_OFFSET), + DW_WDT_DBGFS_REG("stat", WDOG_INTERRUPT_STATUS_REG_OFFSET), + DW_WDT_DBGFS_REG("param5", WDOG_COMP_PARAMS_5_REG_OFFSET), + DW_WDT_DBGFS_REG("param4", WDOG_COMP_PARAMS_4_REG_OFFSET), + DW_WDT_DBGFS_REG("param3", WDOG_COMP_PARAMS_3_REG_OFFSET), + DW_WDT_DBGFS_REG("param2", WDOG_COMP_PARAMS_2_REG_OFFSET), + DW_WDT_DBGFS_REG("param1", WDOG_COMP_PARAMS_1_REG_OFFSET), + DW_WDT_DBGFS_REG("version", WDOG_COMP_VERSION_REG_OFFSET), + DW_WDT_DBGFS_REG("type", WDOG_COMP_TYPE_REG_OFFSET) +}; + +static void dw_wdt_dbgfs_init(struct dw_wdt *dw_wdt) +{ + struct device *dev = dw_wdt->wdd.parent; + struct debugfs_regset32 *regset; + + regset = devm_kzalloc(dev, sizeof(*regset), GFP_KERNEL); + if (!regset) + return; + + regset->regs = dw_wdt_dbgfs_regs; + regset->nregs = ARRAY_SIZE(dw_wdt_dbgfs_regs); + regset->base = dw_wdt->regs; + + dw_wdt->dbgfs_dir = debugfs_create_dir(dev_name(dev), NULL); + + debugfs_create_regset32("registers", 0444, dw_wdt->dbgfs_dir, regset); +} + +static void dw_wdt_dbgfs_clear(struct dw_wdt *dw_wdt) +{ + debugfs_remove_recursive(dw_wdt->dbgfs_dir); +} + +#else /* !CONFIG_DEBUG_FS */ + +static void dw_wdt_dbgfs_init(struct dw_wdt *dw_wdt) {} +static void dw_wdt_dbgfs_clear(struct dw_wdt *dw_wdt) {} + +#endif /* !CONFIG_DEBUG_FS */ + static int dw_wdt_drv_probe(struct platform_device *pdev) { struct device *dev = &pdev->dev; @@ -607,6 +671,8 @@ static int dw_wdt_drv_probe(struct platform_device *pdev) if (ret) goto out_disable_pclk; + dw_wdt_dbgfs_init(dw_wdt); + return 0; out_disable_pclk: @@ -621,6 +687,8 @@ static int dw_wdt_drv_remove(struct platform_device *pdev) { struct dw_wdt *dw_wdt = platform_get_drvdata(pdev); + dw_wdt_dbgfs_clear(dw_wdt); + watchdog_unregister_device(&dw_wdt->wdd); reset_control_assert(dw_wdt->rst); clk_disable_unprepare(dw_wdt->pclk);