/*
   * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
   *                    <benh@kernel.crashing.org>
   *
   *   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; either version 2 of the License, or
   *   (at your option) any later version.
   *
   *   This program is distributed in the hope that it will be useful,
   *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
   *   the GNU General Public License for more details.
   *
   *   You should have received a copy of the GNU General Public License
   *   along with this program;  if not, write to the Free Software
   *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
   */
  
  #undef DEBUG
  
  #include <linux/kernel.h>
  #include <linux/export.h>
  #include <asm/prom.h>
  #include <asm/dcr.h>
  
  #ifdef CONFIG_PPC_DCR_MMIO
  static struct device_node *find_dcr_parent(struct device_node *node)
  {
  	struct device_node *par, *tmp;
  	const u32 *p;
  
  	for (par = of_node_get(node); par;) {
  		if (of_get_property(par, "dcr-controller", NULL))
  			break;
  		p = of_get_property(par, "dcr-parent", NULL);
  		tmp = par;
  		if (p == NULL)
  			par = of_get_parent(par);
  		else
  			par = of_find_node_by_phandle(*p);
  		of_node_put(tmp);
  	}
  	return par;
  }
  #endif
  
  #if defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO)
  
  bool dcr_map_ok_generic(dcr_host_t host)
  {
  	if (host.type == DCR_HOST_NATIVE)
  		return dcr_map_ok_native(host.host.native);
  	else if (host.type == DCR_HOST_MMIO)
  		return dcr_map_ok_mmio(host.host.mmio);
  	else
  		return 0;
  }
  EXPORT_SYMBOL_GPL(dcr_map_ok_generic);
  
  dcr_host_t dcr_map_generic(struct device_node *dev,
  			   unsigned int dcr_n,
  			   unsigned int dcr_c)
  {
  	dcr_host_t host;
  	struct device_node *dp;
  	const char *prop;
  
  	host.type = DCR_HOST_INVALID;
  
  	dp = find_dcr_parent(dev);
  	if (dp == NULL)
  		return host;
  
  	prop = of_get_property(dp, "dcr-access-method", NULL);
  
  	pr_debug("dcr_map_generic(dcr-access-method = %s)
  ", prop);
  
  	if (!strcmp(prop, "native")) {
  		host.type = DCR_HOST_NATIVE;
  		host.host.native = dcr_map_native(dev, dcr_n, dcr_c);
  	} else if (!strcmp(prop, "mmio")) {
  		host.type = DCR_HOST_MMIO;
  		host.host.mmio = dcr_map_mmio(dev, dcr_n, dcr_c);
  	}
  
  	of_node_put(dp);
  	return host;
  }
  EXPORT_SYMBOL_GPL(dcr_map_generic);
  
  void dcr_unmap_generic(dcr_host_t host, unsigned int dcr_c)
  {
  	if (host.type == DCR_HOST_NATIVE)
  		dcr_unmap_native(host.host.native, dcr_c);
  	else if (host.type == DCR_HOST_MMIO)
  		dcr_unmap_mmio(host.host.mmio, dcr_c);
  	else /* host.type == DCR_HOST_INVALID */
  		WARN_ON(true);
  }
  EXPORT_SYMBOL_GPL(dcr_unmap_generic);
  
  u32 dcr_read_generic(dcr_host_t host, unsigned int dcr_n)
  {
  	if (host.type == DCR_HOST_NATIVE)
  		return dcr_read_native(host.host.native, dcr_n);
  	else if (host.type == DCR_HOST_MMIO)
  		return dcr_read_mmio(host.host.mmio, dcr_n);
  	else /* host.type == DCR_HOST_INVALID */
  		WARN_ON(true);
  	return 0;
  }
  EXPORT_SYMBOL_GPL(dcr_read_generic);
  
  void dcr_write_generic(dcr_host_t host, unsigned int dcr_n, u32 value)
  {
  	if (host.type == DCR_HOST_NATIVE)
  		dcr_write_native(host.host.native, dcr_n, value);
  	else if (host.type == DCR_HOST_MMIO)
  		dcr_write_mmio(host.host.mmio, dcr_n, value);
  	else /* host.type == DCR_HOST_INVALID */
  		WARN_ON(true);
  }
  EXPORT_SYMBOL_GPL(dcr_write_generic);
  
  #endif /* defined(CONFIG_PPC_DCR_NATIVE) && defined(CONFIG_PPC_DCR_MMIO) */
  
  unsigned int dcr_resource_start(const struct device_node *np,
  				unsigned int index)
  {
  	unsigned int ds;
  	const u32 *dr = of_get_property(np, "dcr-reg", &ds);
  
  	if (dr == NULL || ds & 1 || index >= (ds / 8))
  		return 0;
  
  	return dr[index * 2];
  }
  EXPORT_SYMBOL_GPL(dcr_resource_start);
  
  unsigned int dcr_resource_len(const struct device_node *np, unsigned int index)
  {
  	unsigned int ds;
  	const u32 *dr = of_get_property(np, "dcr-reg", &ds);
  
  	if (dr == NULL || ds & 1 || index >= (ds / 8))
  		return 0;
  
  	return dr[index * 2 + 1];
  }
  EXPORT_SYMBOL_GPL(dcr_resource_len);
  
  #ifdef CONFIG_PPC_DCR_MMIO
  
  u64 of_translate_dcr_address(struct device_node *dev,
  			     unsigned int dcr_n,
  			     unsigned int *out_stride)
  {
  	struct device_node *dp;
  	const u32 *p;
  	unsigned int stride;
  	u64 ret = OF_BAD_ADDR;
  
  	dp = find_dcr_parent(dev);
  	if (dp == NULL)
  		return OF_BAD_ADDR;
  
  	/* Stride is not properly defined yet, default to 0x10 for Axon */
  	p = of_get_property(dp, "dcr-mmio-stride", NULL);
  	stride = (p == NULL) ? 0x10 : *p;
  
  	/* XXX FIXME: Which property name is to use of the 2 following ? */
  	p = of_get_property(dp, "dcr-mmio-range", NULL);
  	if (p == NULL)
  		p = of_get_property(dp, "dcr-mmio-space", NULL);
  	if (p == NULL)
  		goto done;
  
  	/* Maybe could do some better range checking here */
  	ret = of_translate_address(dp, p);
  	if (ret != OF_BAD_ADDR)
  		ret += (u64)(stride) * (u64)dcr_n;
  	if (out_stride)
  		*out_stride = stride;
  
   done:
  	of_node_put(dp);
  	return ret;
  }
  
  dcr_host_mmio_t dcr_map_mmio(struct device_node *dev,
  			     unsigned int dcr_n,
  			     unsigned int dcr_c)
  {
  	dcr_host_mmio_t ret = { .token = NULL, .stride = 0, .base = dcr_n };
  	u64 addr;
  
  	pr_debug("dcr_map(%s, 0x%x, 0x%x)
  ",
  		 dev->full_name, dcr_n, dcr_c);
  
  	addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
  	pr_debug("translates to addr: 0x%llx, stride: 0x%x
  ",
  		 (unsigned long long) addr, ret.stride);
  	if (addr == OF_BAD_ADDR)
  		return ret;
  	pr_debug("mapping 0x%x bytes
  ", dcr_c * ret.stride);
  	ret.token = ioremap(addr, dcr_c * ret.stride);
  	if (ret.token == NULL)
  		return ret;
  	pr_debug("mapped at 0x%p -> base is 0x%p
  ",
  		 ret.token, ret.token - dcr_n * ret.stride);
  	ret.token -= dcr_n * ret.stride;
  	return ret;
  }
  EXPORT_SYMBOL_GPL(dcr_map_mmio);
  
  void dcr_unmap_mmio(dcr_host_mmio_t host, unsigned int dcr_c)
  {
  	dcr_host_mmio_t h = host;
  
  	if (h.token == NULL)
  		return;
  	h.token += host.base * h.stride;
  	iounmap(h.token);
  	h.token = NULL;
  }
  EXPORT_SYMBOL_GPL(dcr_unmap_mmio);
  
  #endif /* defined(CONFIG_PPC_DCR_MMIO) */
  
  #ifdef CONFIG_PPC_DCR_NATIVE
  DEFINE_SPINLOCK(dcr_ind_lock);
  #endif	/* defined(CONFIG_PPC_DCR_NATIVE) */