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[209.132.180.67]) by mx.google.com with ESMTP id w2si6242978pgb.564.2017.09.26.12.36.12; Tue, 26 Sep 2017 12:36:12 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-gpio-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=neutral (body hash did not verify) header.i=@linaro.org header.s=google header.b=ZZz0qn9K; spf=pass (google.com: best guess record for domain of linux-gpio-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-gpio-owner@vger.kernel.org; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031911AbdIZTgL (ORCPT + 5 others); Tue, 26 Sep 2017 15:36:11 -0400 Received: from mail-pf0-f177.google.com ([209.85.192.177]:46448 "EHLO mail-pf0-f177.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1030327AbdIZTgJ (ORCPT ); Tue, 26 Sep 2017 15:36:09 -0400 Received: by mail-pf0-f177.google.com with SMTP id r68so6031318pfj.3 for ; Tue, 26 Sep 2017 12:36:09 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id; bh=vX4qVmHesDJpHEMf7ddfIxUjenp5wZaLHwi5XMYbons=; b=ZZz0qn9Kb//TmHIGImG9BSImRMNZTTxwkCrIisY3OcG4d/tQ3WO17od6T1X7T9GNOC L1LXYgoGmFUw1Ji4uZolflMRnWqZmdSPxXaFEWIzcmaskQW1vka6T+s+tNkhSrckIl6v CohMVd8+B/ssLsX7Prp/KuyPir6R62tq9qm2s= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=vX4qVmHesDJpHEMf7ddfIxUjenp5wZaLHwi5XMYbons=; b=CTUWSa4LF42PcXPoHyMmqwd6AoJfTBdv7STD/MUsltYEiSISntNb4LCLZEEl1FRD+/ NEW6L8I2m3Hna2HkCxG4OL7s82os4+rI/5Jh9QCofSLg1BJyKfScmE41ZLvksQYsBxEI e5b7EKNfWVf3mAsskqi3c3umcdTtvvefDQepRElpsFF309Md8EGwiDB+rwZc9uXSEKPF GzZ79h6uVRhaz7WFGLN862gAwsOrnTehy9xMTvL1Ls/Sg7bWlHww0pVj7JJQsoegnRZJ x6joKkiDjEmAKfCp4sfFT9ES5LS0OsJixEglldLb70v/a9kuu5NLdqfmvfLhiGoPyhrK 6U2w== X-Gm-Message-State: AHPjjUjceXaYJhbA/mLB3FTVr8rDrkXxt6M0EZg8sPN1+gIs+B3c6mlT wPQatS2IO5bWxBeUyD8dOTxPInI38CI= X-Google-Smtp-Source: AOwi7QA9TX6/+oSjCBJYQSU0S2DddpXHU2sjLXynqeQAsQD70M5UwJ8m+8izmRSFJUK+iG4j3TTAKg== X-Received: by 10.101.83.72 with SMTP id w8mr11941960pgr.226.1506454569223; Tue, 26 Sep 2017 12:36:09 -0700 (PDT) Received: from localhost.localdomain ([70.35.39.2]) by smtp.gmail.com with ESMTPSA id n10sm17511310pfh.121.2017.09.26.12.36.07 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Tue, 26 Sep 2017 12:36:08 -0700 (PDT) From: Linus Walleij To: linux-gpio@vger.kernel.org Cc: Linus Walleij Subject: [PATCH 2/2] gpio: Alter semantics of *raw* operations to actually be raw Date: Tue, 26 Sep 2017 21:36:03 +0200 Message-Id: <20170926193603.21859-1-linus.walleij@linaro.org> X-Mailer: git-send-email 2.13.5 Sender: linux-gpio-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Currently calls to: gpiod_direction_output_raw() gpiod_set_raw_value() gpiod_set_raw_array_value() gpiod_set_raw_value_cansleep() gpiod_set_raw_array_value_cansleep() Respect that we do not want to invert the value written, but will still apply special open drain/open source semantics if the line has an open drain/open source flag. It also forbids us from driving an output marked as an interrupt line. This does not fit with the function name and expected semantics. In the w1 host driver (for example) we need to handle a line as open drain but sometimes force it to pull up, which means we should be able to use the gpiod_set_raw_value() for this, but it currently does not work. There are also use cases where users actually want to drive a line used by an interrupt. This is what they should be expected to use the *raw* accessors for. I have looked over the current users of this API and they do not seem to be using the *raw* accessors with open drain or open source so let's augment this behaviour before we have users expecting the inconsistent semantic. Signed-off-by: Linus Walleij --- drivers/gpio/gpiolib.c | 90 ++++++++++++++++++++++++++------------------------ 1 file changed, 47 insertions(+), 43 deletions(-) -- 2.13.5 -- To unsubscribe from this list: send the line "unsubscribe linux-gpio" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/drivers/gpio/gpiolib.c b/drivers/gpio/gpiolib.c index 3c2065d0aed1..f50518d61c81 100644 --- a/drivers/gpio/gpiolib.c +++ b/drivers/gpio/gpiolib.c @@ -2297,38 +2297,6 @@ static int gpiod_direction_output_raw_commit(struct gpio_desc *desc, int value) int val = !!value; int ret; - /* GPIOs used for IRQs shall not be set as output */ - if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) { - gpiod_err(desc, - "%s: tried to set a GPIO tied to an IRQ as output\n", - __func__); - return -EIO; - } - - if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) { - /* First see if we can enable open drain in hardware */ - ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc), - PIN_CONFIG_DRIVE_OPEN_DRAIN); - if (!ret) - goto set_output_value; - /* Emulate open drain by not actively driving the line high */ - if (val) - return gpiod_direction_input(desc); - } - else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) { - ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc), - PIN_CONFIG_DRIVE_OPEN_SOURCE); - if (!ret) - goto set_output_value; - /* Emulate open source by not actively driving the line low */ - if (!val) - return gpiod_direction_input(desc); - } else { - gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc), - PIN_CONFIG_DRIVE_PUSH_PULL); - } - -set_output_value: if (!gc->set || !gc->direction_output) { gpiod_warn(desc, "%s: missing set() or direction_output() operations\n", @@ -2376,11 +2344,47 @@ EXPORT_SYMBOL_GPL(gpiod_direction_output_raw); */ int gpiod_direction_output(struct gpio_desc *desc, int value) { + struct gpio_chip *gc = desc->gdev->chip; + int ret; + VALIDATE_DESC(desc); if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; else value = !!value; + + /* GPIOs used for IRQs shall not be set as output */ + if (test_bit(FLAG_USED_AS_IRQ, &desc->flags)) { + gpiod_err(desc, + "%s: tried to set a GPIO tied to an IRQ as output\n", + __func__); + return -EIO; + } + + if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) { + /* First see if we can enable open drain in hardware */ + ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc), + PIN_CONFIG_DRIVE_OPEN_DRAIN); + if (!ret) + goto set_output_value; + /* Emulate open drain by not actively driving the line high */ + if (value) + return gpiod_direction_input(desc); + } + else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) { + ret = gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc), + PIN_CONFIG_DRIVE_OPEN_SOURCE); + if (!ret) + goto set_output_value; + /* Emulate open source by not actively driving the line low */ + if (!value) + return gpiod_direction_input(desc); + } else { + gpio_set_drive_single_ended(gc, gpio_chip_hwgpio(desc), + PIN_CONFIG_DRIVE_PUSH_PULL); + } + +set_output_value: return gpiod_direction_output_raw_commit(desc, value); } EXPORT_SYMBOL_GPL(gpiod_direction_output); @@ -2570,12 +2574,7 @@ static void gpiod_set_raw_value_commit(struct gpio_desc *desc, bool value) chip = desc->gdev->chip; trace_gpio_value(desc_to_gpio(desc), 0, value); - if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) - gpio_set_open_drain_value_commit(desc, value); - else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) - gpio_set_open_source_value_commit(desc, value); - else - chip->set(chip, gpio_chip_hwgpio(desc), value); + chip->set(chip, gpio_chip_hwgpio(desc), value); } /* @@ -2630,9 +2629,9 @@ void gpiod_set_array_value_complex(bool raw, bool can_sleep, * collect all normal outputs belonging to the same chip * open drain and open source outputs are set individually */ - if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) { + if (test_bit(FLAG_OPEN_DRAIN, &desc->flags) && !raw) { gpio_set_open_drain_value_commit(desc, value); - } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) { + } else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags) && !raw) { gpio_set_open_source_value_commit(desc, value); } else { __set_bit(hwgpio, mask); @@ -2676,8 +2675,8 @@ EXPORT_SYMBOL_GPL(gpiod_set_raw_value); * @desc: gpio whose value will be assigned * @value: value to assign * - * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW status into - * account + * Set the logical value of the GPIO, i.e. taking its ACTIVE_LOW, + * OPEN_DRAIN and OPEN_SOURCE flags into account. * * This function should be called from contexts where we cannot sleep, and will * complain if the GPIO chip functions potentially sleep. @@ -2689,7 +2688,12 @@ void gpiod_set_value(struct gpio_desc *desc, int value) WARN_ON(desc->gdev->chip->can_sleep); if (test_bit(FLAG_ACTIVE_LOW, &desc->flags)) value = !value; - gpiod_set_raw_value_commit(desc, value); + if (test_bit(FLAG_OPEN_DRAIN, &desc->flags)) + gpio_set_open_drain_value_commit(desc, value); + else if (test_bit(FLAG_OPEN_SOURCE, &desc->flags)) + gpio_set_open_source_value_commit(desc, value); + else + gpiod_set_raw_value_commit(desc, value); } EXPORT_SYMBOL_GPL(gpiod_set_value);