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Commitab78029ecc("drivers/pinctrl: grab default handles from device core") added automatic pin-control management to driver core by looking up and setting any default pinctrl state found in device tree while a device is being probed. This obviously runs into problems as soon as device-tree nodes are reused for child devices which are later also probed as pins would already have been claimed by the ancestor device. For example if a USB host controller claims a pin, its root hub would consequently fail to probe when its device-tree node is set to the node of the controller: pinctrl-single 48002030.pinmux: pin PIN204 already requested by 48064800.ehci; cannot claim for usb1 pinctrl-single 48002030.pinmux: pin-204 (usb1) status -22 pinctrl-single 48002030.pinmux: could not request pin 204 (PIN204) from group usb_dbg_pins on device pinctrl-single usb usb1: Error applying setting, reverse things back usb: probe of usb1 failed with error -22 Fix this by checking the new of_node_reused flag and skipping automatic pinctrl configuration during probe if set. Note that the flag is checked in driver core rather than in pinctrl (e.g. in pinctrl_dt_to_map()) which would specifically have prevented intentional use of a parent's pinctrl properties by a child device (should such a need ever arise). Fixes:ab78029ecc("drivers/pinctrl: grab default handles from device core") Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Johan Hovold <johan@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
107 lines
2.7 KiB
C
107 lines
2.7 KiB
C
/*
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* Driver core interface to the pinctrl subsystem.
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*
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* Copyright (C) 2012 ST-Ericsson SA
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* Written on behalf of Linaro for ST-Ericsson
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* Based on bits of regulator core, gpio core and clk core
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*
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* Author: Linus Walleij <linus.walleij@linaro.org>
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*
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* License terms: GNU General Public License (GPL) version 2
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*/
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#include <linux/device.h>
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#include <linux/pinctrl/devinfo.h>
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#include <linux/pinctrl/consumer.h>
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#include <linux/slab.h>
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/**
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* pinctrl_bind_pins() - called by the device core before probe
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* @dev: the device that is just about to probe
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*/
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int pinctrl_bind_pins(struct device *dev)
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{
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int ret;
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if (dev->of_node_reused)
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return 0;
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dev->pins = devm_kzalloc(dev, sizeof(*(dev->pins)), GFP_KERNEL);
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if (!dev->pins)
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return -ENOMEM;
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dev->pins->p = devm_pinctrl_get(dev);
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if (IS_ERR(dev->pins->p)) {
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dev_dbg(dev, "no pinctrl handle\n");
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ret = PTR_ERR(dev->pins->p);
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goto cleanup_alloc;
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}
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dev->pins->default_state = pinctrl_lookup_state(dev->pins->p,
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PINCTRL_STATE_DEFAULT);
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if (IS_ERR(dev->pins->default_state)) {
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dev_dbg(dev, "no default pinctrl state\n");
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ret = 0;
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goto cleanup_get;
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}
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dev->pins->init_state = pinctrl_lookup_state(dev->pins->p,
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PINCTRL_STATE_INIT);
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if (IS_ERR(dev->pins->init_state)) {
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/* Not supplying this state is perfectly legal */
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dev_dbg(dev, "no init pinctrl state\n");
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ret = pinctrl_select_state(dev->pins->p,
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dev->pins->default_state);
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} else {
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ret = pinctrl_select_state(dev->pins->p, dev->pins->init_state);
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}
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if (ret) {
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dev_dbg(dev, "failed to activate initial pinctrl state\n");
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goto cleanup_get;
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}
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#ifdef CONFIG_PM
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/*
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* If power management is enabled, we also look for the optional
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* sleep and idle pin states, with semantics as defined in
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* <linux/pinctrl/pinctrl-state.h>
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*/
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dev->pins->sleep_state = pinctrl_lookup_state(dev->pins->p,
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PINCTRL_STATE_SLEEP);
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if (IS_ERR(dev->pins->sleep_state))
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/* Not supplying this state is perfectly legal */
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dev_dbg(dev, "no sleep pinctrl state\n");
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dev->pins->idle_state = pinctrl_lookup_state(dev->pins->p,
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PINCTRL_STATE_IDLE);
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if (IS_ERR(dev->pins->idle_state))
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/* Not supplying this state is perfectly legal */
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dev_dbg(dev, "no idle pinctrl state\n");
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#endif
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return 0;
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/*
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* If no pinctrl handle or default state was found for this device,
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* let's explicitly free the pin container in the device, there is
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* no point in keeping it around.
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*/
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cleanup_get:
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devm_pinctrl_put(dev->pins->p);
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cleanup_alloc:
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devm_kfree(dev, dev->pins);
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dev->pins = NULL;
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/* Return deferrals */
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if (ret == -EPROBE_DEFER)
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return ret;
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/* Return serious errors */
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if (ret == -EINVAL)
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return ret;
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/* We ignore errors like -ENOENT meaning no pinctrl state */
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return 0;
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}
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