1// SPDX-License-Identifier: GPL-2.0
  2/*
  3 * Driver core interface to the pinctrl subsystem.
  4 *
  5 * Copyright (C) 2012 ST-Ericsson SA
  6 * Written on behalf of Linaro for ST-Ericsson
  7 * Based on bits of regulator core, gpio core and clk core
  8 *
  9 * Author: Linus Walleij <linus.walleij@linaro.org>
 10 */
 11
 12#include <linux/device.h>
 13#include <linux/pinctrl/devinfo.h>
 14#include <linux/pinctrl/consumer.h>
 15#include <linux/slab.h>
 16
 17/**
 18 * pinctrl_bind_pins() - called by the device core before probe
 19 * @dev: the device that is just about to probe
 20 */
 21int pinctrl_bind_pins(struct device *dev)
 22{
 23	int ret;
 24
 25	if (dev->of_node_reused)
 26		return 0;
 27
 28	dev->pins = devm_kzalloc(dev, sizeof(*(dev->pins)), GFP_KERNEL);
 29	if (!dev->pins)
 30		return -ENOMEM;
 31
 32	dev->pins->p = devm_pinctrl_get(dev);
 33	if (IS_ERR(dev->pins->p)) {
 34		dev_dbg(dev, "no pinctrl handle\n");
 35		ret = PTR_ERR(dev->pins->p);
 36		goto cleanup_alloc;
 37	}
 38
 39	dev->pins->default_state = pinctrl_lookup_state(dev->pins->p,
 40					PINCTRL_STATE_DEFAULT);
 41	if (IS_ERR(dev->pins->default_state)) {
 42		dev_dbg(dev, "no default pinctrl state\n");
 43		ret = 0;
 44		goto cleanup_get;
 45	}
 46
 47	dev->pins->init_state = pinctrl_lookup_state(dev->pins->p,
 48					PINCTRL_STATE_INIT);
 49	if (IS_ERR(dev->pins->init_state)) {
 50		/* Not supplying this state is perfectly legal */
 51		dev_dbg(dev, "no init pinctrl state\n");
 52
 53		ret = pinctrl_select_state(dev->pins->p,
 54					   dev->pins->default_state);
 55	} else {
 56		ret = pinctrl_select_state(dev->pins->p, dev->pins->init_state);
 57	}
 58
 59	if (ret) {
 60		dev_dbg(dev, "failed to activate initial pinctrl state\n");
 61		goto cleanup_get;
 62	}
 63
 64#ifdef CONFIG_PM
 65	/*
 66	 * If power management is enabled, we also look for the optional
 67	 * sleep and idle pin states, with semantics as defined in
 68	 * <linux/pinctrl/pinctrl-state.h>
 69	 */
 70	dev->pins->sleep_state = pinctrl_lookup_state(dev->pins->p,
 71					PINCTRL_STATE_SLEEP);
 72	if (IS_ERR(dev->pins->sleep_state))
 73		/* Not supplying this state is perfectly legal */
 74		dev_dbg(dev, "no sleep pinctrl state\n");
 75
 76	dev->pins->idle_state = pinctrl_lookup_state(dev->pins->p,
 77					PINCTRL_STATE_IDLE);
 78	if (IS_ERR(dev->pins->idle_state))
 79		/* Not supplying this state is perfectly legal */
 80		dev_dbg(dev, "no idle pinctrl state\n");
 81#endif
 82
 83	return 0;
 84
 85	/*
 86	 * If no pinctrl handle or default state was found for this device,
 87	 * let's explicitly free the pin container in the device, there is
 88	 * no point in keeping it around.
 89	 */
 90cleanup_get:
 91	devm_pinctrl_put(dev->pins->p);
 92cleanup_alloc:
 93	devm_kfree(dev, dev->pins);
 94	dev->pins = NULL;
 95
 96	/* Return deferrals */
 97	if (ret == -EPROBE_DEFER)
 98		return ret;
 99	/* Return serious errors */
100	if (ret == -EINVAL)
101		return ret;
102	/* We ignore errors like -ENOENT meaning no pinctrl state */
103
104	return 0;
105}