linux/drivers/base/pinctrl.c
<<
>>
Prefs
   1/*
   2 * Driver core interface to the pinctrl subsystem.
   3 *
   4 * Copyright (C) 2012 ST-Ericsson SA
   5 * Written on behalf of Linaro for ST-Ericsson
   6 * Based on bits of regulator core, gpio core and clk core
   7 *
   8 * Author: Linus Walleij <linus.walleij@linaro.org>
   9 *
  10 * License terms: GNU General Public License (GPL) version 2
  11 */
  12
  13#include <linux/device.h>
  14#include <linux/pinctrl/devinfo.h>
  15#include <linux/pinctrl/consumer.h>
  16#include <linux/slab.h>
  17
  18/**
  19 * pinctrl_bind_pins() - called by the device core before probe
  20 * @dev: the device that is just about to probe
  21 */
  22int pinctrl_bind_pins(struct device *dev)
  23{
  24        int ret;
  25
  26        dev->pins = devm_kzalloc(dev, sizeof(*(dev->pins)), GFP_KERNEL);
  27        if (!dev->pins)
  28                return -ENOMEM;
  29
  30        dev->pins->p = devm_pinctrl_get(dev);
  31        if (IS_ERR(dev->pins->p)) {
  32                dev_dbg(dev, "no pinctrl handle\n");
  33                ret = PTR_ERR(dev->pins->p);
  34                goto cleanup_alloc;
  35        }
  36
  37        dev->pins->default_state = pinctrl_lookup_state(dev->pins->p,
  38                                        PINCTRL_STATE_DEFAULT);
  39        if (IS_ERR(dev->pins->default_state)) {
  40                dev_dbg(dev, "no default pinctrl state\n");
  41                ret = 0;
  42                goto cleanup_get;
  43        }
  44
  45        ret = pinctrl_select_state(dev->pins->p, dev->pins->default_state);
  46        if (ret) {
  47                dev_dbg(dev, "failed to activate default pinctrl state\n");
  48                goto cleanup_get;
  49        }
  50
  51#ifdef CONFIG_PM
  52        /*
  53         * If power management is enabled, we also look for the optional
  54         * sleep and idle pin states, with semantics as defined in
  55         * <linux/pinctrl/pinctrl-state.h>
  56         */
  57        dev->pins->sleep_state = pinctrl_lookup_state(dev->pins->p,
  58                                        PINCTRL_STATE_SLEEP);
  59        if (IS_ERR(dev->pins->sleep_state))
  60                /* Not supplying this state is perfectly legal */
  61                dev_dbg(dev, "no sleep pinctrl state\n");
  62
  63        dev->pins->idle_state = pinctrl_lookup_state(dev->pins->p,
  64                                        PINCTRL_STATE_IDLE);
  65        if (IS_ERR(dev->pins->idle_state))
  66                /* Not supplying this state is perfectly legal */
  67                dev_dbg(dev, "no idle pinctrl state\n");
  68#endif
  69
  70        return 0;
  71
  72        /*
  73         * If no pinctrl handle or default state was found for this device,
  74         * let's explicitly free the pin container in the device, there is
  75         * no point in keeping it around.
  76         */
  77cleanup_get:
  78        devm_pinctrl_put(dev->pins->p);
  79cleanup_alloc:
  80        devm_kfree(dev, dev->pins);
  81        dev->pins = NULL;
  82
  83        /* Only return deferrals */
  84        if (ret != -EPROBE_DEFER)
  85                ret = 0;
  86
  87        return ret;
  88}
  89
lxr.linux.no kindly hosted by Redpill Linpro AS, provider of Linux consulting and operations services since 1995.