drivers/misc/mic/bus/cosm_bus.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Intel MIC Platform Software Stack (MPSS)
   4  *
   5  * Copyright(c) 2015 Intel Corporation.
   6  *
   7  * Intel MIC COSM Bus Driver
   8  */
   9 #include <linux/slab.h>
  10 #include <linux/module.h>
  11 #include <linux/idr.h>
  12 #include "cosm_bus.h"
  13
  14 /* Unique numbering for cosm devices. */
  15 static DEFINE_IDA(cosm_index_ida);
  16
  17 static int cosm_dev_probe(struct device *d)
  18 {
  19         struct cosm_device *dev = dev_to_cosm(d);
  20         struct cosm_driver *drv = drv_to_cosm(dev->dev.driver);
  21
  22         return drv->probe(dev);
  23 }
  24
  25 static int cosm_dev_remove(struct device *d)
  26 {
  27         struct cosm_device *dev = dev_to_cosm(d);
  28         struct cosm_driver *drv = drv_to_cosm(dev->dev.driver);
  29
  30         drv->remove(dev);
  31         return 0;
  32 }
  33
  34 static struct bus_type cosm_bus = {
  35         .name  = "cosm_bus",
  36         .probe = cosm_dev_probe,
  37         .remove = cosm_dev_remove,
  38 };
  39
  40 int cosm_register_driver(struct cosm_driver *driver)
  41 {
  42         driver->driver.bus = &cosm_bus;
  43         return driver_register(&driver->driver);
  44 }
  45 EXPORT_SYMBOL_GPL(cosm_register_driver);
  46
  47 void cosm_unregister_driver(struct cosm_driver *driver)
  48 {
  49         driver_unregister(&driver->driver);
  50 }
  51 EXPORT_SYMBOL_GPL(cosm_unregister_driver);
  52
  53 static inline void cosm_release_dev(struct device *d)
  54 {
  55         struct cosm_device *cdev = dev_to_cosm(d);
  56
  57         kfree(cdev);
  58 }
  59
  60 struct cosm_device *
  61 cosm_register_device(struct device *pdev, struct cosm_hw_ops *hw_ops)
  62 {
  63         struct cosm_device *cdev;
  64         int ret;
  65
  66         cdev = kzalloc(sizeof(*cdev), GFP_KERNEL);
  67         if (!cdev)
  68                 return ERR_PTR(-ENOMEM);
  69
  70         cdev->dev.parent = pdev;
  71         cdev->dev.release = cosm_release_dev;
  72         cdev->hw_ops = hw_ops;
  73         dev_set_drvdata(&cdev->dev, cdev);
  74         cdev->dev.bus = &cosm_bus;
  75
  76         /* Assign a unique device index and hence name */
  77         ret = ida_simple_get(&cosm_index_ida, 0, 0, GFP_KERNEL);
  78         if (ret < 0)
  79                 goto free_cdev;
  80
  81         cdev->index = ret;
  82         cdev->dev.id = ret;
  83         dev_set_name(&cdev->dev, "cosm-dev%u", cdev->index);
  84
  85         ret = device_register(&cdev->dev);
  86         if (ret)
  87                 goto ida_remove;
  88         return cdev;
  89 ida_remove:
  90         ida_simple_remove(&cosm_index_ida, cdev->index);
  91 free_cdev:
  92         put_device(&cdev->dev);
  93         return ERR_PTR(ret);
  94 }
  95 EXPORT_SYMBOL_GPL(cosm_register_device);
  96
  97 void cosm_unregister_device(struct cosm_device *dev)
  98 {
  99         int index = dev->index; /* save for after device release */
 100
 101         device_unregister(&dev->dev);
 102         ida_simple_remove(&cosm_index_ida, index);
 103 }
 104 EXPORT_SYMBOL_GPL(cosm_unregister_device);
 105
 106 struct cosm_device *cosm_find_cdev_by_id(int id)
 107 {
 108         struct device *dev = subsys_find_device_by_id(&cosm_bus, id, NULL);
 109
 110         return dev ? container_of(dev, struct cosm_device, dev) : NULL;
 111 }
 112 EXPORT_SYMBOL_GPL(cosm_find_cdev_by_id);
 113
 114 static int __init cosm_init(void)
 115 {
 116         return bus_register(&cosm_bus);
 117 }
 118
 119 static void __exit cosm_exit(void)
 120 {
 121         bus_unregister(&cosm_bus);
 122         ida_destroy(&cosm_index_ida);
 123 }
 124
 125 core_initcall(cosm_init);
 126 module_exit(cosm_exit);
 127
 128 MODULE_AUTHOR("Intel Corporation");
 129 MODULE_DESCRIPTION("Intel(R) MIC card OS state management bus driver");
 130 MODULE_LICENSE("GPL v2");