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[193.12.47.89]) by smtp.gmail.com with ESMTPSA id g10-20020a19ac0a000000b00441e497867fsm2321462lfc.93.2022.03.22.15.30.02 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Mar 2022 15:30:03 -0700 (PDT) From: Tobias Waldekranz To: Wim Van Sebroeck , Guenter Roeck Cc: linux-watchdog@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH] watchdog: gpio_wdt: Support GPO lines with the toggle algorithm Date: Tue, 22 Mar 2022 23:29:11 +0100 Message-Id: <20220322222911.519238-1-tobias@waldekranz.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 Organization: Westermo Precedence: bulk List-ID: X-Mailing-List: linux-watchdog@vger.kernel.org Support using GPO lines (i.e. GPIOs that are output-only) with gpio_wdt using the "toggle" algorithm. Since its inception, gpio_wdt has configured its GPIO line as an input when using the "toggle" algorithm, even though it is used as an output when kicking. This needlessly barred hardware with output-only pins from using the driver. Signed-off-by: Tobias Waldekranz --- Hi, This patch has been in our downstream tree for a long time. We need it because our kick GPIO can't be used as an input. What I really can't figure out is why the driver would request the pin as in input, when it's always going to end up being used as an output anyway. So I thought I'd send it upstream in the hopes of either getting it merged, or an explanation as to why it is needed. drivers/watchdog/gpio_wdt.c | 13 +++++-------- 1 file changed, 5 insertions(+), 8 deletions(-) diff --git a/drivers/watchdog/gpio_wdt.c b/drivers/watchdog/gpio_wdt.c index 0923201ce874..f7686688e0e2 100644 --- a/drivers/watchdog/gpio_wdt.c +++ b/drivers/watchdog/gpio_wdt.c @@ -108,7 +108,6 @@ static int gpio_wdt_probe(struct platform_device *pdev) struct device *dev = &pdev->dev; struct device_node *np = dev->of_node; struct gpio_wdt_priv *priv; - enum gpiod_flags gflags; unsigned int hw_margin; const char *algo; int ret; @@ -122,17 +121,15 @@ static int gpio_wdt_probe(struct platform_device *pdev) ret = of_property_read_string(np, "hw_algo", &algo); if (ret) return ret; - if (!strcmp(algo, "toggle")) { + + if (!strcmp(algo, "toggle")) priv->hw_algo = HW_ALGO_TOGGLE; - gflags = GPIOD_IN; - } else if (!strcmp(algo, "level")) { + else if (!strcmp(algo, "level")) priv->hw_algo = HW_ALGO_LEVEL; - gflags = GPIOD_OUT_LOW; - } else { + else return -EINVAL; - } - priv->gpiod = devm_gpiod_get(dev, NULL, gflags); + priv->gpiod = devm_gpiod_get(dev, NULL, GPIOD_OUT_LOW); if (IS_ERR(priv->gpiod)) return PTR_ERR(priv->gpiod);