1 files changed, 222 insertions, 0 deletions
diff --git a/arch/powerpc/sysdev/dcr.c b/arch/powerpc/sysdev/dcr.c
new file mode 100644
index 000000000..22991e112
--- /dev/null
+++ b/arch/powerpc/sysdev/dcr.c
@@ -0,0 +1,222 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * (c) Copyright 2006 Benjamin Herrenschmidt, IBM Corp.
+ *                    <benh@kernel.crashing.org>
+ */
+
+#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 false;
+}
+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)\n", 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
+
+static 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(%pOF, 0x%x, 0x%x)\n",
+		 dev, dcr_n, dcr_c);
+
+	addr = of_translate_dcr_address(dev, dcr_n, &ret.stride);
+	pr_debug("translates to addr: 0x%llx, stride: 0x%x\n",
+		 (unsigned long long) addr, ret.stride);
+	if (addr == OF_BAD_ADDR)
+		return ret;
+	pr_debug("mapping 0x%x bytes\n", 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\n",
+		 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);
+EXPORT_SYMBOL_GPL(dcr_ind_lock);
+#endif	/* defined(CONFIG_PPC_DCR_NATIVE) */
+