text: /*
   * Industry-pack bus support functions.
   *
   * (C) 2011 Samuel Iglesias Gonsalvez <siglesia@cern.ch>, CERN
   * (C) 2012 Samuel Iglesias Gonsalvez <siglesias@igalia.com>, Igalia
   *
   * This program is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License as published by the Free
   * Software Foundation; version 2 of the License.
   */
  
  #include <linux/module.h>
  #include <linux/slab.h>
  #include <linux/idr.h>
  #include <asm/io.h>
  #include "ipack.h"
  
  #define to_ipack_dev(device) container_of(device, struct ipack_device, dev)
  #define to_ipack_driver(drv) container_of(drv, struct ipack_driver, driver)
  
  static DEFINE_IDA(ipack_ida);
  
  static void ipack_device_release(struct device *dev)
  {
  	struct ipack_device *device = to_ipack_dev(dev);
  	kfree(device->id);
  	kfree(device);
  }
  
  static inline const struct ipack_device_id *
  ipack_match_one_device(const struct ipack_device_id *id,
  		       const struct ipack_device *device)
  {
  	if ((id->format == IPACK_ANY_FORMAT ||
  				id->format == device->id_format) &&
  	    (id->vendor == IPACK_ANY_ID || id->vendor == device->id_vendor) &&
  	    (id->device == IPACK_ANY_ID || id->device == device->id_device))
  		return id;
  	return NULL;
  }
  
  static const struct ipack_device_id *
  ipack_match_id(const struct ipack_device_id *ids, struct ipack_device *idev)
  {
  	if (ids) {
  		while (ids->vendor || ids->device) {
  			if (ipack_match_one_device(ids, idev))
  				return ids;
  			ids++;
  		}
  	}
  	return NULL;
  }
  
  static int ipack_bus_match(struct device *dev, struct device_driver *drv)
  {
  	struct ipack_device *idev = to_ipack_dev(dev);
  	struct ipack_driver *idrv = to_ipack_driver(drv);
  	const struct ipack_device_id *found_id;
  
  	found_id = ipack_match_id(idrv->id_table, idev);
  	return found_id ? 1 : 0;
  }
  
  static int ipack_bus_probe(struct device *device)
  {
  	struct ipack_device *dev = to_ipack_dev(device);
  	struct ipack_driver *drv = to_ipack_driver(device->driver);
  
  	if (!drv->ops->probe)
  		return -EINVAL;
  
  	return drv->ops->probe(dev);
  }
  
  static int ipack_bus_remove(struct device *device)
  {
  	struct ipack_device *dev = to_ipack_dev(device);
  	struct ipack_driver *drv = to_ipack_driver(device->driver);
  
  	if (!drv->ops->remove)
  		return -EINVAL;
  
  	drv->ops->remove(dev);
  	return 0;
  }
  
  #ifdef CONFIG_HOTPLUG
  
  static int ipack_uevent(struct device *dev, struct kobj_uevent_env *env)
  {
  	struct ipack_device *idev;
  
  	if (!dev)
  		return -ENODEV;
  
  	idev = to_ipack_dev(dev);
  
  	if (add_uevent_var(env,
  			   "MODALIAS=ipack:f%02Xv%08Xd%08X", idev->id_format,
  			   idev->id_vendor, idev->id_device))
  		return -ENOMEM;
  
  	return 0;
  }
  
  #else /* !CONFIG_HOTPLUG */
  
  #define ipack_uevent NULL
  
  #endif /* !CONFIG_HOTPLUG */
  
  #define ipack_device_attr(field, format_string)				\
  static ssize_t								\
  field##_show(struct device *dev, struct device_attribute *attr,		\
  		char *buf)						\
  {									\
  	struct ipack_device *idev = to_ipack_dev(dev);			\
  	return sprintf(buf, format_string, idev->field);		\
  }
  
  static ssize_t id_show(struct device *dev,
  		       struct device_attribute *attr, char *buf)
  {
  	unsigned int i, c, l, s;
  	struct ipack_device *idev = to_ipack_dev(dev);
  
  
  	switch (idev->id_format) {
  	case IPACK_ID_VERSION_1:
  		l = 0x7; s = 1; break;
  	case IPACK_ID_VERSION_2:
  		l = 0xf; s = 2; break;
  	default:
  		return -EIO;
  	}
  	c = 0;
  	for (i = 0; i < idev->id_avail; i++) {
  		if (i > 0) {
  			if ((i & l) == 0)
  				buf[c++] = '\n';
  			else if ((i & s) == 0)
  				buf[c++] = ' ';
  		}
  		sprintf(&buf[c], "%02x", idev->id[i]);
  		c += 2;
  	}
  	buf[c++] = '\n';
  	return c;
  }
  
  static ssize_t
  id_vendor_show(struct device *dev, struct device_attribute *attr, char *buf)
  {
  	struct ipack_device *idev = to_ipack_dev(dev);
  	switch (idev->id_format) {
  	case IPACK_ID_VERSION_1:
  		return sprintf(buf, "0x%02x\n", idev->id_vendor);
  	case IPACK_ID_VERSION_2:
  		return sprintf(buf, "0x%06x\n", idev->id_vendor);
  	default:
  		return -EIO;
  	}
  }
  
  static ssize_t
  id_device_show(struct device *dev, struct device_attribute *attr, char *buf)
  {
  	struct ipack_device *idev = to_ipack_dev(dev);
  	switch (idev->id_format) {
  	case IPACK_ID_VERSION_1:
  		return sprintf(buf, "0x%02x\n", idev->id_device);
  	case IPACK_ID_VERSION_2:
  		return sprintf(buf, "0x%04x\n", idev->id_device);
  	default:
  		return -EIO;
  	}
  }
  
  static ssize_t modalias_show(struct device *dev, struct device_attribute *attr,
  			     char *buf)
  {
  	struct ipack_device *idev = to_ipack_dev(dev);
  
  	return sprintf(buf, "ipac:f%02Xv%08Xd%08X", idev->id_format,
  		       idev->id_vendor, idev->id_device);
  }
  
  ipack_device_attr(id_format, "0x%hhu\n");
  
  static struct device_attribute ipack_dev_attrs[] = {
  	__ATTR_RO(id),
  	__ATTR_RO(id_device),
  	__ATTR_RO(id_format),
  	__ATTR_RO(id_vendor),
  	__ATTR_RO(modalias),
  };
  
  static struct bus_type ipack_bus_type = {
  	.name      = "ipack",
  	.probe     = ipack_bus_probe,
  	.match     = ipack_bus_match,
  	.remove    = ipack_bus_remove,
  	.dev_attrs = ipack_dev_attrs,
  	.uevent	   = ipack_uevent,
  };
  
  struct ipack_bus_device *ipack_bus_register(struct device *parent, int slots,
  					    const struct ipack_bus_ops *ops)
  {
  	int bus_nr;
  	struct ipack_bus_device *bus;
  
  	bus = kzalloc(sizeof(struct ipack_bus_device), GFP_KERNEL);
  	if (!bus)
  		return NULL;
  
  	bus_nr = ida_simple_get(&ipack_ida, 0, 0, GFP_KERNEL);
  	if (bus_nr < 0) {
  		kfree(bus);
  		return NULL;
  	}
  
  	bus->bus_nr = bus_nr;
  	bus->parent = parent;
  	bus->slots = slots;
  	bus->ops = ops;
  	return bus;
  }
  EXPORT_SYMBOL_GPL(ipack_bus_register);
  
  static int ipack_unregister_bus_member(struct device *dev, void *data)
  {
  	struct ipack_device *idev = to_ipack_dev(dev);
  	struct ipack_bus_device *bus = data;
  
  	if (idev->bus_nr == bus->bus_nr)
  		ipack_device_unregister(idev);
  
  	return 1;
  }
  
  int ipack_bus_unregister(struct ipack_bus_device *bus)
  {
  	bus_for_each_dev(&ipack_bus_type, NULL, bus, ipack_unregister_bus_member);
  	ida_simple_remove(&ipack_ida, bus->bus_nr);
  	kfree(bus);
  	return 0;
  }
  EXPORT_SYMBOL_GPL(ipack_bus_unregister);
  
  int ipack_driver_register(struct ipack_driver *edrv, struct module *owner,
  			  const char *name)
  {
  	edrv->driver.owner = owner;
  	edrv->driver.name = name;
  	edrv->driver.bus = &ipack_bus_type;
  	return driver_register(&edrv->driver);
  }
  EXPORT_SYMBOL_GPL(ipack_driver_register);
  
  void ipack_driver_unregister(struct ipack_driver *edrv)
  {
  	driver_unregister(&edrv->driver);
  }
  EXPORT_SYMBOL_GPL(ipack_driver_unregister);
  
  static u16 ipack_crc_byte(u16 crc, u8 c)
  {
  	int i;
  
  	crc ^= c << 8;
  	for (i = 0; i < 8; i++)
  		crc = (crc << 1) ^ ((crc & 0x8000) ? 0x1021 : 0);
  	return crc;
  }
  
  /*
   * The algorithm in lib/crc-ccitt.c does not seem to apply since it uses the
   * opposite bit ordering.
   */
  static u8 ipack_calc_crc1(struct ipack_device *dev)
  {
  	u8 c;
  	u16 crc;
  	unsigned int i;
  
  	crc = 0xffff;
  	for (i = 0; i < dev->id_avail; i++) {
  		c = (i != 11) ? dev->id[i] : 0;
  		crc = ipack_crc_byte(crc, c);
  	}
  	crc = ~crc;
  	return crc & 0xff;
  }
  
  static u16 ipack_calc_crc2(struct ipack_device *dev)
  {
  	u8 c;
  	u16 crc;
  	unsigned int i;
  
  	crc = 0xffff;
  	for (i = 0; i < dev->id_avail; i++) {
  		c = ((i != 0x18) && (i != 0x19)) ? dev->id[i] : 0;
  		crc = ipack_crc_byte(crc, c);
  	}
  	crc = ~crc;
  	return crc;
  }
  
  static void ipack_parse_id1(struct ipack_device *dev)
  {
  	u8 *id = dev->id;
  	u8 crc;
  
  	dev->id_vendor = id[4];
  	dev->id_device = id[5];
  	dev->speed_8mhz = 1;
  	dev->speed_32mhz = (id[7] == 'H');
  	crc = ipack_calc_crc1(dev);
  	dev->id_crc_correct = (crc == id[11]);
  	if (!dev->id_crc_correct) {
  		dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
  				id[11], crc);
  	}
  }
  
  static void ipack_parse_id2(struct ipack_device *dev)
  {
  	__be16 *id = (__be16 *) dev->id;
  	u16 flags, crc;
  
  	dev->id_vendor = ((be16_to_cpu(id[3]) & 0xff) << 16)
  			 + be16_to_cpu(id[4]);
  	dev->id_device = be16_to_cpu(id[5]);
  	flags = be16_to_cpu(id[10]);
  	dev->speed_8mhz = !!(flags & 2);
  	dev->speed_32mhz = !!(flags & 4);
  	crc = ipack_calc_crc2(dev);
  	dev->id_crc_correct = (crc == be16_to_cpu(id[12]));
  	if (!dev->id_crc_correct) {
  		dev_warn(&dev->dev, "ID CRC invalid found 0x%x, expected 0x%x.\n",
  				id[11], crc);
  	}
  }
  
  static int ipack_device_read_id(struct ipack_device *dev)
  {
  	u8 __iomem *idmem;
  	int i;
  	int ret = 0;
  
  	ret = dev->bus->ops->map_space(dev, 0, IPACK_ID_SPACE);
  	if (ret) {
  		dev_err(&dev->dev, "error mapping memory\n");
  		return ret;
  	}
  	idmem = dev->id_space.address;
  
  	/* Determine ID PROM Data Format.  If we find the ids "IPAC" or "IPAH"
  	 * we are dealing with a IndustryPack  format 1 device.  If we detect
  	 * "VITA4 " (16 bit big endian formatted) we are dealing with a
  	 * IndustryPack format 2 device */
  	if ((ioread8(idmem + 1) == 'I') &&
  			(ioread8(idmem + 3) == 'P') &&
  			(ioread8(idmem + 5) == 'A') &&
  			((ioread8(idmem + 7) == 'C') ||
  			 (ioread8(idmem + 7) == 'H'))) {
  		dev->id_format = IPACK_ID_VERSION_1;
  		dev->id_avail = ioread8(idmem + 0x15);
  		if ((dev->id_avail < 0x0c) || (dev->id_avail > 0x40)) {
  			dev_warn(&dev->dev, "invalid id size");
  			dev->id_avail = 0x0c;
  		}
  	} else if ((ioread8(idmem + 0) == 'I') &&
  			(ioread8(idmem + 1) == 'V') &&
  			(ioread8(idmem + 2) == 'A') &&
  			(ioread8(idmem + 3) == 'T') &&
  			(ioread8(idmem + 4) == ' ') &&
  			(ioread8(idmem + 5) == '4')) {
  		dev->id_format = IPACK_ID_VERSION_2;
  		dev->id_avail = ioread16be(idmem + 0x16);
  		if ((dev->id_avail < 0x1a) || (dev->id_avail > 0x40)) {
  			dev_warn(&dev->dev, "invalid id size");
  			dev->id_avail = 0x1a;
  		}
  	} else {
  		dev->id_format = IPACK_ID_VERSION_INVALID;
  		dev->id_avail = 0;
  	}
  
  	if (!dev->id_avail) {
  		ret = -ENODEV;
  		goto out;
  	}
  
  	/* Obtain the amount of memory required to store a copy of the complete
  	 * ID ROM contents */
  	dev->id = kmalloc(dev->id_avail, GFP_KERNEL);
  	if (!dev->id) {
  		dev_err(&dev->dev, "dev->id alloc failed.\n");
  		ret = -ENOMEM;
  		goto out;
  	}
  	for (i = 0; i < dev->id_avail; i++) {
  		if (dev->id_format == IPACK_ID_VERSION_1)
  			dev->id[i] = ioread8(idmem + (i << 1) + 1);
  		else
  			dev->id[i] = ioread8(idmem + i);
  	}
  
  	/* now we can finally work with the copy */
  	switch (dev->id_format) {
  	case IPACK_ID_VERSION_1:
  		ipack_parse_id1(dev);
  		break;
  	case IPACK_ID_VERSION_2:
  		ipack_parse_id2(dev);
  		break;
  	}
  
  out:
  	dev->bus->ops->unmap_space(dev, IPACK_ID_SPACE);
  
  	return ret;
  }
  
  struct ipack_device *ipack_device_register(struct ipack_bus_device *bus,
  					   int slot)
  {
  	int ret;
  	struct ipack_device *dev;
  
  	dev = kzalloc(sizeof(struct ipack_device), GFP_KERNEL);
  	if (!dev)
  		return NULL;
  
  	dev->dev.bus = &ipack_bus_type;
  	dev->dev.release = ipack_device_release;
  	dev->dev.parent = bus->parent;
  	dev->slot = slot;
  	dev->bus_nr = bus->bus_nr;
  	dev->bus = bus;
  	dev_set_name(&dev->dev,
  		     "ipack-dev.%u.%u", dev->bus_nr, dev->slot);
  
  	if (bus->ops->set_clockrate(dev, 8))
  		dev_warn(&dev->dev, "failed to switch to 8 MHz operation for reading of device ID.\n");
  	if (bus->ops->reset_timeout(dev))
  		dev_warn(&dev->dev, "failed to reset potential timeout.");
  
  	ret = ipack_device_read_id(dev);
  	if (ret < 0) {
  		dev_err(&dev->dev, "error reading device id section.\n");
  		kfree(dev);
  		return NULL;
  	}
  
  	/* if the device supports 32 MHz operation, use it. */
  	if (dev->speed_32mhz) {
  		ret = bus->ops->set_clockrate(dev, 32);
  		if (ret < 0)
  			dev_err(&dev->dev, "failed to switch to 32 MHz operation.\n");
  	}
  
  	ret = device_register(&dev->dev);
  	if (ret < 0) {
  		kfree(dev->id);
  		kfree(dev);
  		return NULL;
  	}
  
  	return dev;
  }
  EXPORT_SYMBOL_GPL(ipack_device_register);
  
  void ipack_device_unregister(struct ipack_device *dev)
  {
  	device_unregister(&dev->dev);
  }
  EXPORT_SYMBOL_GPL(ipack_device_unregister);
  
  static int __init ipack_init(void)
  {
  	ida_init(&ipack_ida);
  	return bus_register(&ipack_bus_type);
  }
  
  static void __exit ipack_exit(void)
  {
  	bus_unregister(&ipack_bus_type);
  	ida_destroy(&ipack_ida);
  }
  
  module_init(ipack_init);
  module_exit(ipack_exit);
  
  MODULE_AUTHOR("Samuel Iglesias Gonsalvez <siglesias@igalia.com>");
  MODULE_LICENSE("GPL");
  MODULE_DESCRIPTION("Industry-pack bus core");
  