From mboxrd@z Thu Jan 1 00:00:00 1970 From: Brian Masney Subject: [PATCH v2 5/7] pinctrl: qcom: spmi-gpio: fix gpio-hog related boot issues Date: Wed, 31 Oct 2018 20:11:47 -0400 Message-ID: <20181101001149.13453-6-masneyb@onstation.org> References: <20181101001149.13453-1-masneyb@onstation.org> Return-path: In-Reply-To: <20181101001149.13453-1-masneyb@onstation.org> Sender: linux-kernel-owner@vger.kernel.org To: sre@kernel.org, robh+dt@kernel.org, mark.rutland@arm.com, andy.gross@linaro.org, david.brown@linaro.org, bjorn.andersson@linaro.org, linus.walleij@linaro.org Cc: linux-pm@vger.kernel.org, devicetree@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-soc@vger.kernel.org, linux-gpio@vger.kernel.org, jonathan@marek.ca, masneyb@onstation.org List-Id: devicetree@vger.kernel.org When attempting to setup up a gpio hog, device probing would repeatedly fail with -EPROBE_DEFERED errors. It was caused by a circular dependency between the gpio and pinctrl frameworks. If the gpio-ranges property is present in device tree, then the gpio framework will handle the gpio pin registration and eliminate the circular dependency. See Christian Lamparter's commit a86caa9ba5d7 ("pinctrl: msm: fix gpio-hog related boot issues") for a detailed commit message that explains the issue in much more detail. The code comment in this commit came from Christian's commit. Signed-off-by: Brian Masney --- drivers/pinctrl/qcom/pinctrl-spmi-gpio.c | 21 +++++++++++++++++---- 1 file changed, 17 insertions(+), 4 deletions(-) diff --git a/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c b/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c index a29efbe08f48..4c1ff9a1d156 100644 --- a/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c +++ b/drivers/pinctrl/qcom/pinctrl-spmi-gpio.c @@ -1028,10 +1028,23 @@ static int pmic_gpio_probe(struct platform_device *pdev) return ret; } - ret = gpiochip_add_pin_range(&state->chip, dev_name(dev), 0, 0, npins); - if (ret) { - dev_err(dev, "failed to add pin range\n"); - goto err_range; + /* + * For DeviceTree-supported systems, the gpio core checks the + * pinctrl's device node for the "gpio-ranges" property. + * If it is present, it takes care of adding the pin ranges + * for the driver. In this case the driver can skip ahead. + * + * In order to remain compatible with older, existing DeviceTree + * files which don't set the "gpio-ranges" property or systems that + * utilize ACPI the driver has to call gpiochip_add_pin_range(). + */ + if (!of_property_read_bool(dev->of_node, "gpio-ranges")) { + ret = gpiochip_add_pin_range(&state->chip, dev_name(dev), 0, 0, + npins); + if (ret) { + dev_err(dev, "failed to add pin range\n"); + goto err_range; + } } return 0; -- 2.17.2