drivers/base/pinctrl.c

   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  * License terms: GNU General Public License (GPL) version 2
  12  */
  13
  14 #include <linux/device.h>
  15 #include <linux/pinctrl/devinfo.h>
  16 #include <linux/pinctrl/consumer.h>
  17 #include <linux/slab.h>
  18
  19 /**
  20  * pinctrl_bind_pins() - called by the device core before probe
  21  * @dev: the device that is just about to probe
  22  */
  23 int pinctrl_bind_pins(struct device *dev)
  24 {
  25         int ret;
  26
  27         if (dev->of_node_reused)
  28                 return 0;
  29
  30         dev->pins = devm_kzalloc(dev, sizeof(*(dev->pins)), GFP_KERNEL);
  31         if (!dev->pins)
  32                 return -ENOMEM;
  33
  34         dev->pins->p = devm_pinctrl_get(dev);
  35         if (IS_ERR(dev->pins->p)) {
  36                 dev_dbg(dev, "no pinctrl handle\n");
  37                 ret = PTR_ERR(dev->pins->p);
  38                 goto cleanup_alloc;
  39         }
  40
  41         dev->pins->default_state = pinctrl_lookup_state(dev->pins->p,
  42                                         PINCTRL_STATE_DEFAULT);
  43         if (IS_ERR(dev->pins->default_state)) {
  44                 dev_dbg(dev, "no default pinctrl state\n");
  45                 ret = 0;
  46                 goto cleanup_get;
  47         }
  48
  49         dev->pins->init_state = pinctrl_lookup_state(dev->pins->p,
  50                                         PINCTRL_STATE_INIT);
  51         if (IS_ERR(dev->pins->init_state)) {
  52                 /* Not supplying this state is perfectly legal */
  53                 dev_dbg(dev, "no init pinctrl state\n");
  54
  55                 ret = pinctrl_select_state(dev->pins->p,
  56                                            dev->pins->default_state);
  57         } else {
  58                 ret = pinctrl_select_state(dev->pins->p, dev->pins->init_state);
  59         }
  60
  61         if (ret) {
  62                 dev_dbg(dev, "failed to activate initial pinctrl state\n");
  63                 goto cleanup_get;
  64         }
  65
  66 #ifdef CONFIG_PM
  67         /*
  68          * If power management is enabled, we also look for the optional
  69          * sleep and idle pin states, with semantics as defined in
  70          * <linux/pinctrl/pinctrl-state.h>
  71          */
  72         dev->pins->sleep_state = pinctrl_lookup_state(dev->pins->p,
  73                                         PINCTRL_STATE_SLEEP);
  74         if (IS_ERR(dev->pins->sleep_state))
  75                 /* Not supplying this state is perfectly legal */
  76                 dev_dbg(dev, "no sleep pinctrl state\n");
  77
  78         dev->pins->idle_state = pinctrl_lookup_state(dev->pins->p,
  79                                         PINCTRL_STATE_IDLE);
  80         if (IS_ERR(dev->pins->idle_state))
  81                 /* Not supplying this state is perfectly legal */
  82                 dev_dbg(dev, "no idle pinctrl state\n");
  83 #endif
  84
  85         return 0;
  86
  87         /*
  88          * If no pinctrl handle or default state was found for this device,
  89          * let's explicitly free the pin container in the device, there is
  90          * no point in keeping it around.
  91          */
  92 cleanup_get:
  93         devm_pinctrl_put(dev->pins->p);
  94 cleanup_alloc:
  95         devm_kfree(dev, dev->pins);
  96         dev->pins = NULL;
  97
  98         /* Return deferrals */
  99         if (ret == -EPROBE_DEFER)
 100                 return ret;
 101         /* Return serious errors */
 102         if (ret == -EINVAL)
 103                 return ret;
 104         /* We ignore errors like -ENOENT meaning no pinctrl state */
 105
 106         return 0;
 107 }