drivers/misc/mic/bus/mic_bus.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * Intel MIC Platform Software Stack (MPSS)
   4  *
   5  * Copyright(c) 2014 Intel Corporation.
   6  *
   7  * Intel MIC Bus driver.
   8  *
   9  * This implementation is very similar to the the virtio bus driver
  10  * implementation @ drivers/virtio/virtio.c
  11  */
  12 #include <linux/slab.h>
  13 #include <linux/module.h>
  14 #include <linux/idr.h>
  15 #include <linux/mic_bus.h>
  16
  17 static ssize_t device_show(struct device *d,
  18                            struct device_attribute *attr, char *buf)
  19 {
  20         struct mbus_device *dev = dev_to_mbus(d);
  21         return sprintf(buf, "0x%04x\n", dev->id.device);
  22 }
  23 static DEVICE_ATTR_RO(device);
  24
  25 static ssize_t vendor_show(struct device *d,
  26                            struct device_attribute *attr, char *buf)
  27 {
  28         struct mbus_device *dev = dev_to_mbus(d);
  29         return sprintf(buf, "0x%04x\n", dev->id.vendor);
  30 }
  31 static DEVICE_ATTR_RO(vendor);
  32
  33 static ssize_t modalias_show(struct device *d,
  34                              struct device_attribute *attr, char *buf)
  35 {
  36         struct mbus_device *dev = dev_to_mbus(d);
  37         return sprintf(buf, "mbus:d%08Xv%08X\n",
  38                        dev->id.device, dev->id.vendor);
  39 }
  40 static DEVICE_ATTR_RO(modalias);
  41
  42 static struct attribute *mbus_dev_attrs[] = {
  43         &dev_attr_device.attr,
  44         &dev_attr_vendor.attr,
  45         &dev_attr_modalias.attr,
  46         NULL,
  47 };
  48 ATTRIBUTE_GROUPS(mbus_dev);
  49
  50 static inline int mbus_id_match(const struct mbus_device *dev,
  51                                 const struct mbus_device_id *id)
  52 {
  53         if (id->device != dev->id.device && id->device != MBUS_DEV_ANY_ID)
  54                 return 0;
  55
  56         return id->vendor == MBUS_DEV_ANY_ID || id->vendor == dev->id.vendor;
  57 }
  58
  59 /*
  60  * This looks through all the IDs a driver claims to support.  If any of them
  61  * match, we return 1 and the kernel will call mbus_dev_probe().
  62  */
  63 static int mbus_dev_match(struct device *dv, struct device_driver *dr)
  64 {
  65         unsigned int i;
  66         struct mbus_device *dev = dev_to_mbus(dv);
  67         const struct mbus_device_id *ids;
  68
  69         ids = drv_to_mbus(dr)->id_table;
  70         for (i = 0; ids[i].device; i++)
  71                 if (mbus_id_match(dev, &ids[i]))
  72                         return 1;
  73         return 0;
  74 }
  75
  76 static int mbus_uevent(struct device *dv, struct kobj_uevent_env *env)
  77 {
  78         struct mbus_device *dev = dev_to_mbus(dv);
  79
  80         return add_uevent_var(env, "MODALIAS=mbus:d%08Xv%08X",
  81                               dev->id.device, dev->id.vendor);
  82 }
  83
  84 static int mbus_dev_probe(struct device *d)
  85 {
  86         int err;
  87         struct mbus_device *dev = dev_to_mbus(d);
  88         struct mbus_driver *drv = drv_to_mbus(dev->dev.driver);
  89
  90         err = drv->probe(dev);
  91         if (!err)
  92                 if (drv->scan)
  93                         drv->scan(dev);
  94         return err;
  95 }
  96
  97 static int mbus_dev_remove(struct device *d)
  98 {
  99         struct mbus_device *dev = dev_to_mbus(d);
 100         struct mbus_driver *drv = drv_to_mbus(dev->dev.driver);
 101
 102         drv->remove(dev);
 103         return 0;
 104 }
 105
 106 static struct bus_type mic_bus = {
 107         .name  = "mic_bus",
 108         .match = mbus_dev_match,
 109         .dev_groups = mbus_dev_groups,
 110         .uevent = mbus_uevent,
 111         .probe = mbus_dev_probe,
 112         .remove = mbus_dev_remove,
 113 };
 114
 115 int mbus_register_driver(struct mbus_driver *driver)
 116 {
 117         driver->driver.bus = &mic_bus;
 118         return driver_register(&driver->driver);
 119 }
 120 EXPORT_SYMBOL_GPL(mbus_register_driver);
 121
 122 void mbus_unregister_driver(struct mbus_driver *driver)
 123 {
 124         driver_unregister(&driver->driver);
 125 }
 126 EXPORT_SYMBOL_GPL(mbus_unregister_driver);
 127
 128 static void mbus_release_dev(struct device *d)
 129 {
 130         struct mbus_device *mbdev = dev_to_mbus(d);
 131         kfree(mbdev);
 132 }
 133
 134 struct mbus_device *
 135 mbus_register_device(struct device *pdev, int id, const struct dma_map_ops *dma_ops,
 136                      struct mbus_hw_ops *hw_ops, int index,
 137                      void __iomem *mmio_va)
 138 {
 139         int ret;
 140         struct mbus_device *mbdev;
 141
 142         mbdev = kzalloc(sizeof(*mbdev), GFP_KERNEL);
 143         if (!mbdev)
 144                 return ERR_PTR(-ENOMEM);
 145
 146         mbdev->mmio_va = mmio_va;
 147         mbdev->dev.parent = pdev;
 148         mbdev->id.device = id;
 149         mbdev->id.vendor = MBUS_DEV_ANY_ID;
 150         mbdev->dev.dma_ops = dma_ops;
 151         mbdev->dev.dma_mask = &mbdev->dev.coherent_dma_mask;
 152         dma_set_mask(&mbdev->dev, DMA_BIT_MASK(64));
 153         mbdev->dev.release = mbus_release_dev;
 154         mbdev->hw_ops = hw_ops;
 155         mbdev->dev.bus = &mic_bus;
 156         mbdev->index = index;
 157         dev_set_name(&mbdev->dev, "mbus-dev%u", mbdev->index);
 158         /*
 159          * device_register() causes the bus infrastructure to look for a
 160          * matching driver.
 161          */
 162         ret = device_register(&mbdev->dev);
 163         if (ret)
 164                 goto free_mbdev;
 165         return mbdev;
 166 free_mbdev:
 167         put_device(&mbdev->dev);
 168         return ERR_PTR(ret);
 169 }
 170 EXPORT_SYMBOL_GPL(mbus_register_device);
 171
 172 void mbus_unregister_device(struct mbus_device *mbdev)
 173 {
 174         device_unregister(&mbdev->dev);
 175 }
 176 EXPORT_SYMBOL_GPL(mbus_unregister_device);
 177
 178 static int __init mbus_init(void)
 179 {
 180         return bus_register(&mic_bus);
 181 }
 182
 183 static void __exit mbus_exit(void)
 184 {
 185         bus_unregister(&mic_bus);
 186 }
 187
 188 core_initcall(mbus_init);
 189 module_exit(mbus_exit);
 190
 191 MODULE_AUTHOR("Intel Corporation");
 192 MODULE_DESCRIPTION("Intel(R) MIC Bus driver");
 193 MODULE_LICENSE("GPL v2");