[POWERPC] cpm: Describe multi-user ram in its own device node.

The way the current CPM binding describes available multi-user (a.k.a.
dual-ported) RAM doesn't work well when there are multiple free regions,
and it doesn't work at all if the region doesn't begin at the start of
the muram area (as the hardware needs to be programmed with offsets into
this area).  The latter situation can happen with SMC UARTs on CPM2, as its
parameter RAM is relocatable, u-boot puts it at zero, and the kernel doesn't
support moving it.

It is now described with a muram node, similar to QE.  The current CPM
binding is sufficiently recent (i.e. never appeared in an official release)
that compatibility with existing device trees is not an issue.

The code supporting the new binding is shared between cpm1 and cpm2, rather
than remain separated.  QE should be able to use this code as well, once
minor fixes are made to its device trees.

Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

1 files changed, 159 insertions, 0 deletions

diff --git a/arch/powerpc/sysdev/cpm_common.c b/arch/powerpc/sysdev/cpm_common.c
index 9daa6ac6767..66c8ad4cfce 100644
--- a/arch/powerpc/sysdev/cpm_common.c
+++ b/arch/powerpc/sysdev/cpm_common.c
@@ -5,15 +5,27 @@
  *
  * Copyright 2007 Freescale Semiconductor, Inc.
  *
+ * Some parts derived from commproc.c/cpm2_common.c, which is:
+ * Copyright (c) 1997 Dan error_act (dmalek@jlc.net)
+ * Copyright (c) 1999-2001 Dan Malek <dan@embeddedalley.com>
+ * Copyright (c) 2000 MontaVista Software, Inc (source@mvista.com)
+ * 2006 (c) MontaVista Software, Inc.
+ * Vitaly Bordug <vbordug@ru.mvista.com>
+ *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of version 2 of the GNU General Public License as
  * published by the Free Software Foundation.
  */
 
 #include <linux/init.h>
+#include <linux/of_device.h>
+
 #include <asm/udbg.h>
 #include <asm/io.h>
 #include <asm/system.h>
+#include <asm/rheap.h>
+#include <asm/cpm.h>
+
 #include <mm/mmu_decl.h>
 
 #ifdef CONFIG_PPC_EARLY_DEBUG_CPM
@@ -41,6 +53,153 @@ void __init udbg_init_cpm(void)
 		setbat(1, 0xf0000000, 0xf0000000, 1024*1024, _PAGE_IO);
 #endif
 		udbg_putc = udbg_putc_cpm;
+		udbg_putc('X');
 	}
 }
 #endif
+
+#ifdef CONFIG_PPC_CPM_NEW_BINDING
+static spinlock_t cpm_muram_lock;
+static rh_block_t cpm_boot_muram_rh_block[16];
+static rh_info_t cpm_muram_info;
+static u8 __iomem *muram_vbase;
+static phys_addr_t muram_pbase;
+
+/* Max address size we deal with */
+#define OF_MAX_ADDR_CELLS	4
+
+int __init cpm_muram_init(void)
+{
+	struct device_node *np;
+	struct resource r;
+	u32 zero[OF_MAX_ADDR_CELLS] = {};
+	resource_size_t max = 0;
+	int i = 0;
+	int ret = 0;
+
+	printk("cpm_muram_init\n");
+
+	spin_lock_init(&cpm_muram_lock);
+	/* initialize the info header */
+	rh_init(&cpm_muram_info, 1,
+	        sizeof(cpm_boot_muram_rh_block) /
+	        sizeof(cpm_boot_muram_rh_block[0]),
+	        cpm_boot_muram_rh_block);
+
+	np = of_find_compatible_node(NULL, NULL, "fsl,cpm-muram-data");
+	if (!np) {
+		printk(KERN_ERR "Cannot find CPM muram data node");
+		ret = -ENODEV;
+		goto out;
+	}
+
+	muram_pbase = of_translate_address(np, zero);
+	if (muram_pbase == (phys_addr_t)OF_BAD_ADDR) {
+		printk(KERN_ERR "Cannot translate zero through CPM muram node");
+		ret = -ENODEV;
+		goto out;
+	}
+
+	while (of_address_to_resource(np, i++, &r) == 0) {
+		if (r.end > max)
+			max = r.end;
+
+		rh_attach_region(&cpm_muram_info, r.start - muram_pbase,
+		                 r.end - r.start + 1);
+	}
+
+	muram_vbase = ioremap(muram_pbase, max - muram_pbase + 1);
+	if (!muram_vbase) {
+		printk(KERN_ERR "Cannot map CPM muram");
+		ret = -ENOMEM;
+	}
+
+out:
+	of_node_put(np);
+	return ret;
+}
+
+/**
+ * cpm_muram_alloc - allocate the requested size worth of multi-user ram
+ * @size: number of bytes to allocate
+ * @align: requested alignment, in bytes
+ *
+ * This function returns an offset into the muram area.
+ * Use cpm_dpram_addr() to get the virtual address of the area.
+ * Use cpm_muram_free() to free the allocation.
+ */
+unsigned long cpm_muram_alloc(unsigned long size, unsigned long align)
+{
+	unsigned long start;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cpm_muram_lock, flags);
+	cpm_muram_info.alignment = align;
+	start = rh_alloc(&cpm_muram_info, size, "commproc");
+	spin_unlock_irqrestore(&cpm_muram_lock, flags);
+
+	return start;
+}
+EXPORT_SYMBOL(cpm_muram_alloc);
+
+/**
+ * cpm_muram_free - free a chunk of multi-user ram
+ * @offset: The beginning of the chunk as returned by cpm_muram_alloc().
+ */
+int cpm_muram_free(unsigned long offset)
+{
+	int ret;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cpm_muram_lock, flags);
+	ret = rh_free(&cpm_muram_info, offset);
+	spin_unlock_irqrestore(&cpm_muram_lock, flags);
+
+	return ret;
+}
+EXPORT_SYMBOL(cpm_muram_free);
+
+/**
+ * cpm_muram_alloc_fixed - reserve a specific region of multi-user ram
+ * @offset: the offset into the muram area to reserve
+ * @size: the number of bytes to reserve
+ *
+ * This function returns "start" on success, -ENOMEM on failure.
+ * Use cpm_dpram_addr() to get the virtual address of the area.
+ * Use cpm_muram_free() to free the allocation.
+ */
+unsigned long cpm_muram_alloc_fixed(unsigned long offset, unsigned long size)
+{
+	unsigned long start;
+	unsigned long flags;
+
+	spin_lock_irqsave(&cpm_muram_lock, flags);
+	cpm_muram_info.alignment = 1;
+	start = rh_alloc_fixed(&cpm_muram_info, offset, size, "commproc");
+	spin_unlock_irqrestore(&cpm_muram_lock, flags);
+
+	return start;
+}
+EXPORT_SYMBOL(cpm_muram_alloc_fixed);
+
+/**
+ * cpm_muram_addr - turn a muram offset into a virtual address
+ * @offset: muram offset to convert
+ */
+void __iomem *cpm_muram_addr(unsigned long offset)
+{
+	return muram_vbase + offset;
+}
+EXPORT_SYMBOL(cpm_muram_addr);
+
+/**
+ * cpm_muram_phys - turn a muram virtual address into a DMA address
+ * @offset: virtual address from cpm_muram_addr() to convert
+ */
+dma_addr_t cpm_muram_dma(void __iomem *addr)
+{
+	return muram_pbase + ((u8 __iomem *)addr - muram_vbase);
+}
+EXPORT_SYMBOL(cpm_muram_dma);
+
+#endif /* CONFIG_PPC_CPM_NEW_BINDING */