linux/drivers/misc/mic/bus/mic_bus.c
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   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
  28static 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}
  34static DEVICE_ATTR_RO(device);
  35
  36static 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}
  42static DEVICE_ATTR_RO(vendor);
  43
  44static 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}
  51static DEVICE_ATTR_RO(modalias);
  52
  53static struct attribute *mbus_dev_attrs[] = {
  54        &dev_attr_device.attr,
  55        &dev_attr_vendor.attr,
  56        &dev_attr_modalias.attr,
  57        NULL,
  58};
  59ATTRIBUTE_GROUPS(mbus_dev);
  60
  61static 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 */
  74static 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
  87static 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
  95static 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
 108static 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
 117static 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
 126int mbus_register_driver(struct mbus_driver *driver)
 127{
 128        driver->driver.bus = &mic_bus;
 129        return driver_register(&driver->driver);
 130}
 131EXPORT_SYMBOL_GPL(mbus_register_driver);
 132
 133void mbus_unregister_driver(struct mbus_driver *driver)
 134{
 135        driver_unregister(&driver->driver);
 136}
 137EXPORT_SYMBOL_GPL(mbus_unregister_driver);
 138
 139static void mbus_release_dev(struct device *d)
 140{
 141        struct mbus_device *mbdev = dev_to_mbus(d);
 142        kfree(mbdev);
 143}
 144
 145struct mbus_device *
 146mbus_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;
 177free_mbdev:
 178        put_device(&mbdev->dev);
 179        return ERR_PTR(ret);
 180}
 181EXPORT_SYMBOL_GPL(mbus_register_device);
 182
 183void mbus_unregister_device(struct mbus_device *mbdev)
 184{
 185        device_unregister(&mbdev->dev);
 186}
 187EXPORT_SYMBOL_GPL(mbus_unregister_device);
 188
 189static int __init mbus_init(void)
 190{
 191        return bus_register(&mic_bus);
 192}
 193
 194static void __exit mbus_exit(void)
 195{
 196        bus_unregister(&mic_bus);
 197}
 198
 199core_initcall(mbus_init);
 200module_exit(mbus_exit);
 201
 202MODULE_AUTHOR("Intel Corporation");
 203MODULE_DESCRIPTION("Intel(R) MIC Bus driver");
 204MODULE_LICENSE("GPL v2");
 205