drivers/misc/mic/bus/mic_bus.c

   1 /*
   2  * Intel MIC Platform Software Stack (MPSS)
   3  *
   4  * Copyright(c) 2014 Intel Corporation.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License, version 2, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  13  * General Public License for more details.
  14  *
  15  * The full GNU General Public License is included in this distribution in
  16  * the file called "COPYING".
  17  *
  18  * Intel MIC Bus driver.
  19  *
  20  * This implementation is very similar to the the virtio bus driver
  21  * implementation @ drivers/virtio/virtio.c
  22  */
  23 #include <linux/slab.h>
  24 #include <linux/module.h>
  25 #include <linux/idr.h>
  26 #include <linux/mic_bus.h>
  27
  28 static ssize_t device_show(struct device *d,
  29                            struct device_attribute *attr, char *buf)
  30 {
  31         struct mbus_device *dev = dev_to_mbus(d);
  32         return sprintf(buf, "0x%04x\n", dev->id.device);
  33 }
  34 static DEVICE_ATTR_RO(device);
  35
  36 static ssize_t vendor_show(struct device *d,
  37                            struct device_attribute *attr, char *buf)
  38 {
  39         struct mbus_device *dev = dev_to_mbus(d);
  40         return sprintf(buf, "0x%04x\n", dev->id.vendor);
  41 }
  42 static DEVICE_ATTR_RO(vendor);
  43
  44 static ssize_t modalias_show(struct device *d,
  45                              struct device_attribute *attr, char *buf)
  46 {
  47         struct mbus_device *dev = dev_to_mbus(d);
  48         return sprintf(buf, "mbus:d%08Xv%08X\n",
  49                        dev->id.device, dev->id.vendor);
  50 }
  51 static DEVICE_ATTR_RO(modalias);
  52
  53 static struct attribute *mbus_dev_attrs[] = {
  54         &dev_attr_device.attr,
  55         &dev_attr_vendor.attr,
  56         &dev_attr_modalias.attr,
  57         NULL,
  58 };
  59 ATTRIBUTE_GROUPS(mbus_dev);
  60
  61 static inline int mbus_id_match(const struct mbus_device *dev,
  62                                 const struct mbus_device_id *id)
  63 {
  64         if (id->device != dev->id.device && id->device != MBUS_DEV_ANY_ID)
  65                 return 0;
  66
  67         return id->vendor == MBUS_DEV_ANY_ID || id->vendor == dev->id.vendor;
  68 }
  69
  70 /*
  71  * This looks through all the IDs a driver claims to support.  If any of them
  72  * match, we return 1 and the kernel will call mbus_dev_probe().
  73  */
  74 static int mbus_dev_match(struct device *dv, struct device_driver *dr)
  75 {
  76         unsigned int i;
  77         struct mbus_device *dev = dev_to_mbus(dv);
  78         const struct mbus_device_id *ids;
  79
  80         ids = drv_to_mbus(dr)->id_table;
  81         for (i = 0; ids[i].device; i++)
  82                 if (mbus_id_match(dev, &ids[i]))
  83                         return 1;
  84         return 0;
  85 }
  86
  87 static int mbus_uevent(struct device *dv, struct kobj_uevent_env *env)
  88 {
  89         struct mbus_device *dev = dev_to_mbus(dv);
  90
  91         return add_uevent_var(env, "MODALIAS=mbus:d%08Xv%08X",
  92                               dev->id.device, dev->id.vendor);
  93 }
  94
  95 static int mbus_dev_probe(struct device *d)
  96 {
  97         int err;
  98         struct mbus_device *dev = dev_to_mbus(d);
  99         struct mbus_driver *drv = drv_to_mbus(dev->dev.driver);
 100
 101         err = drv->probe(dev);
 102         if (!err)
 103                 if (drv->scan)
 104                         drv->scan(dev);
 105         return err;
 106 }
 107
 108 static int mbus_dev_remove(struct device *d)
 109 {
 110         struct mbus_device *dev = dev_to_mbus(d);
 111         struct mbus_driver *drv = drv_to_mbus(dev->dev.driver);
 112
 113         drv->remove(dev);
 114         return 0;
 115 }
 116
 117 static struct bus_type mic_bus = {
 118         .name  = "mic_bus",
 119         .match = mbus_dev_match,
 120         .dev_groups = mbus_dev_groups,
 121         .uevent = mbus_uevent,
 122         .probe = mbus_dev_probe,
 123         .remove = mbus_dev_remove,
 124 };
 125
 126 int mbus_register_driver(struct mbus_driver *driver)
 127 {
 128         driver->driver.bus = &mic_bus;
 129         return driver_register(&driver->driver);
 130 }
 131 EXPORT_SYMBOL_GPL(mbus_register_driver);
 132
 133 void mbus_unregister_driver(struct mbus_driver *driver)
 134 {
 135         driver_unregister(&driver->driver);
 136 }
 137 EXPORT_SYMBOL_GPL(mbus_unregister_driver);
 138
 139 static void mbus_release_dev(struct device *d)
 140 {
 141         struct mbus_device *mbdev = dev_to_mbus(d);
 142         kfree(mbdev);
 143 }
 144
 145 struct mbus_device *
 146 mbus_register_device(struct device *pdev, int id, const struct dma_map_ops *dma_ops,
 147                      struct mbus_hw_ops *hw_ops, int index,
 148                      void __iomem *mmio_va)
 149 {
 150         int ret;
 151         struct mbus_device *mbdev;
 152
 153         mbdev = kzalloc(sizeof(*mbdev), GFP_KERNEL);
 154         if (!mbdev)
 155                 return ERR_PTR(-ENOMEM);
 156
 157         mbdev->mmio_va = mmio_va;
 158         mbdev->dev.parent = pdev;
 159         mbdev->id.device = id;
 160         mbdev->id.vendor = MBUS_DEV_ANY_ID;
 161         mbdev->dev.dma_ops = dma_ops;
 162         mbdev->dev.dma_mask = &mbdev->dev.coherent_dma_mask;
 163         dma_set_mask(&mbdev->dev, DMA_BIT_MASK(64));
 164         mbdev->dev.release = mbus_release_dev;
 165         mbdev->hw_ops = hw_ops;
 166         mbdev->dev.bus = &mic_bus;
 167         mbdev->index = index;
 168         dev_set_name(&mbdev->dev, "mbus-dev%u", mbdev->index);
 169         /*
 170          * device_register() causes the bus infrastructure to look for a
 171          * matching driver.
 172          */
 173         ret = device_register(&mbdev->dev);
 174         if (ret)
 175                 goto free_mbdev;
 176         return mbdev;
 177 free_mbdev:
 178         put_device(&mbdev->dev);
 179         return ERR_PTR(ret);
 180 }
 181 EXPORT_SYMBOL_GPL(mbus_register_device);
 182
 183 void mbus_unregister_device(struct mbus_device *mbdev)
 184 {
 185         device_unregister(&mbdev->dev);
 186 }
 187 EXPORT_SYMBOL_GPL(mbus_unregister_device);
 188
 189 static int __init mbus_init(void)
 190 {
 191         return bus_register(&mic_bus);
 192 }
 193
 194 static void __exit mbus_exit(void)
 195 {
 196         bus_unregister(&mic_bus);
 197 }
 198
 199 core_initcall(mbus_init);
 200 module_exit(mbus_exit);
 201
 202 MODULE_AUTHOR("Intel Corporation");
 203 MODULE_DESCRIPTION("Intel(R) MIC Bus driver");
 204 MODULE_LICENSE("GPL v2");