[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>

9 files changed, 263 insertions, 42 deletions

diff --git a/arch/powerpc/Kconfig.debug b/arch/powerpc/Kconfig.debug
index f4e5d22..464f9b4 100644
--- a/arch/powerpc/Kconfig.debug
+++ b/arch/powerpc/Kconfig.debug
@@ -245,9 +245,9 @@ config PPC_EARLY_DEBUG_44x_PHYSHIGH
 config PPC_EARLY_DEBUG_CPM_ADDR
 	hex "CPM UART early debug transmit descriptor address"
 	depends on PPC_EARLY_DEBUG_CPM
-	default "0xfa202808" if PPC_EP88XC
-	default "0xf0000808" if CPM2
-	default "0xff002808" if CPM1
+	default "0xfa202008" if PPC_EP88XC
+	default "0xf0000008" if CPM2
+	default "0xff002008" if CPM1
 	help
 	  This specifies the address of the transmit descriptor
 	  used for early debug output.  Because it is needed before
diff --git a/arch/powerpc/boot/cpm-serial.c b/arch/powerpc/boot/cpm-serial.c
index fcb8b5e..28296fa 100644
--- a/arch/powerpc/boot/cpm-serial.c
+++ b/arch/powerpc/boot/cpm-serial.c
@@ -56,7 +56,8 @@ static struct cpm_smc *smc;
 static struct cpm_scc *scc;
 struct cpm_bd *tbdf, *rbdf;
 static u32 cpm_cmd;
-static u8 *dpram_start;
+static u8 *muram_start;
+static u32 muram_offset;
 
 static void (*do_cmd)(int op);
 static void (*enable_port)(void);
@@ -114,13 +115,12 @@ static void scc_enable_port(void)
 
 static int cpm_serial_open(void)
 {
-	int dpaddr = 0x800;
 	disable_port();
 
 	out_8(&param->rfcr, 0x10);
 	out_8(&param->tfcr, 0x10);
 
-	rbdf = (struct cpm_bd *)(dpram_start + dpaddr);
+	rbdf = (struct cpm_bd *)muram_start;
 	rbdf->addr = (u8 *)(rbdf + 2);
 	rbdf->sc = 0xa000;
 	rbdf->len = 1;
@@ -131,8 +131,8 @@ static int cpm_serial_open(void)
 	tbdf->len = 1;
 
 	sync();
-	out_be16(&param->rbase, dpaddr);
-	out_be16(&param->tbase, dpaddr + sizeof(struct cpm_bd));
+	out_be16(&param->rbase, muram_offset);
+	out_be16(&param->tbase, muram_offset + sizeof(struct cpm_bd));
 
 	do_cmd(CPM_CMD_INIT_RX_TX);
 
@@ -178,7 +178,7 @@ int cpm_console_init(void *devp, struct serial_console_data *scdp)
 	void *reg_virt[2];
 	int is_smc = 0, is_cpm2 = 0, n;
 	unsigned long reg_phys;
-	void *parent;
+	void *parent, *muram;
 
 	if (dt_is_compatible(devp, "fsl,cpm1-smc-uart")) {
 		is_smc = 1;
@@ -229,16 +229,36 @@ int cpm_console_init(void *devp, struct serial_console_data *scdp)
 
 	n = getprop(parent, "virtual-reg", reg_virt, sizeof(reg_virt));
 	if (n < (int)sizeof(reg_virt)) {
-		for (n = 0; n < 2; n++) {
-			if (!dt_xlate_reg(parent, n, &reg_phys, NULL))
-				return -1;
+		if (!dt_xlate_reg(parent, 0, &reg_phys, NULL))
+			return -1;
 
-			reg_virt[n] = (void *)reg_phys;
-		}
+		reg_virt[0] = (void *)reg_phys;
 	}
 
 	cpcr = reg_virt[0];
-	dpram_start = reg_virt[1];
+
+	muram = finddevice("/soc/cpm/muram/data");
+	if (!muram)
+		return -1;
+
+	/* For bootwrapper-compatible device trees, we assume that the first
+	 * entry has at least 18 bytes, and that #address-cells/#data-cells
+	 * is one for both parent and child.
+	 */
+
+	n = getprop(muram, "virtual-reg", reg_virt, sizeof(reg_virt));
+	if (n < (int)sizeof(reg_virt)) {
+		if (!dt_xlate_reg(muram, 0, &reg_phys, NULL))
+			return -1;
+
+		reg_virt[0] = (void *)reg_phys;
+	}
+
+	muram_start = reg_virt[0];
+
+	n = getprop(muram, "reg", &muram_offset, 4);
+	if (n < 4)
+		return -1;
 
 	scdp->open = cpm_serial_open;
 	scdp->putc = cpm_serial_putc;
diff --git a/arch/powerpc/boot/dts/ep88xc.dts b/arch/powerpc/boot/dts/ep88xc.dts
index 0406fc5..02705f2 100644
--- a/arch/powerpc/boot/dts/ep88xc.dts
+++ b/arch/powerpc/boot/dts/ep88xc.dts
@@ -142,9 +142,20 @@
 			command-proc = <9c0>;
 			interrupts = <0>;	// cpm error interrupt
 			interrupt-parent = <&CPM_PIC>;
-			reg = <9c0 40 2000 1c00>;
+			reg = <9c0 40>;
 			ranges;
 
+			muram@2000 {
+				#address-cells = <1>;
+				#size-cells = <1>;
+				ranges = <0 2000 2000>;
+
+				data@0 {
+					compatible = "fsl,cpm-muram-data";
+					reg = <0 1c00>;
+				};
+			};
+
 			brg@9f0 {
 				compatible = "fsl,mpc885-brg",
 				             "fsl,cpm1-brg",
diff --git a/arch/powerpc/boot/dts/mpc8272ads.dts b/arch/powerpc/boot/dts/mpc8272ads.dts
index 3fe991d..188179d 100644
--- a/arch/powerpc/boot/dts/mpc8272ads.dts
+++ b/arch/powerpc/boot/dts/mpc8272ads.dts
@@ -124,6 +124,17 @@
 			reg = <119c0 30 0 2000>;
 			ranges;
 
+			muram@0 {
+				#address-cells = <1>;
+				#size-cells = <1>;
+				ranges = <0 0 10000>;
+
+				data@0 {
+					compatible = "fsl,cpm-muram-data";
+					reg = <0 2000 9800 800>;
+				};
+			};
+
 			brg@119f0 {
 				compatible = "fsl,mpc8272-brg",
 				             "fsl,cpm2-brg",
diff --git a/arch/powerpc/boot/dts/mpc885ads.dts b/arch/powerpc/boot/dts/mpc885ads.dts
index cbcd16f..8848e63 100644
--- a/arch/powerpc/boot/dts/mpc885ads.dts
+++ b/arch/powerpc/boot/dts/mpc885ads.dts
@@ -148,9 +148,20 @@
 			command-proc = <9c0>;
 			interrupts = <0>;	// cpm error interrupt
 			interrupt-parent = <&CPM_PIC>;
-			reg = <9c0 40 2000 1c00>;
+			reg = <9c0 40>;
 			ranges;
 
+			muram@2000 {
+				#address-cells = <1>;
+				#size-cells = <1>;
+				ranges = <0 2000 2000>;
+
+				data@0 {
+					compatible = "fsl,cpm-muram-data";
+					reg = <0 1c00>;
+				};
+			};
+
 			brg@9f0 {
 				compatible = "fsl,mpc885-brg",
 				             "fsl,cpm1-brg",
diff --git a/arch/powerpc/boot/dts/pq2fads.dts b/arch/powerpc/boot/dts/pq2fads.dts
index 54e8bd1..2d564921 100644
--- a/arch/powerpc/boot/dts/pq2fads.dts
+++ b/arch/powerpc/boot/dts/pq2fads.dts
@@ -119,9 +119,20 @@
 			#size-cells = <1>;
 			#interrupt-cells = <2>;
 			compatible = "fsl,mpc8280-cpm", "fsl,cpm2";
-			reg = <119c0 30 0 2000>;
+			reg = <119c0 30>;
 			ranges;
 
+			muram@0 {
+				#address-cells = <1>;
+				#size-cells = <1>;
+				ranges = <0 0 10000>;
+
+				data@0 {
+					compatible = "fsl,cpm-muram-data";
+					reg = <0 2000 9800 800>;
+				};
+			};
+
 			brg@119f0 {
 				compatible = "fsl,mpc8280-brg",
 				             "fsl,cpm2-brg",
diff --git a/arch/powerpc/sysdev/commproc.c b/arch/powerpc/sysdev/commproc.c
index 428eb8c..f6a6378 100644
--- a/arch/powerpc/sysdev/commproc.c
+++ b/arch/powerpc/sysdev/commproc.c
@@ -39,12 +39,15 @@
 #include <asm/tlbflush.h>
 #include <asm/rheap.h>
 #include <asm/prom.h>
+#include <asm/cpm.h>
 
 #include <asm/fs_pd.h>
 
 #define CPM_MAP_SIZE    (0x4000)
 
+#ifndef CONFIG_PPC_CPM_NEW_BINDING
 static void m8xx_cpm_dpinit(void);
+#endif
 static uint host_buffer; /* One page of host buffer */
 static uint host_end;    /* end + 1 */
 cpm8xx_t __iomem *cpmp;  /* Pointer to comm processor space */
@@ -193,7 +196,7 @@ end:
 	return sirq;
 }
 
-void cpm_reset(void)
+void __init cpm_reset(void)
 {
 	sysconf8xx_t __iomem *siu_conf;
 
@@ -229,8 +232,12 @@ void cpm_reset(void)
 	out_be32(&siu_conf->sc_sdcr, 1);
 	immr_unmap(siu_conf);
 
+#ifdef CONFIG_PPC_CPM_NEW_BINDING
+	cpm_muram_init();
+#else
 	/* Reclaim the DP memory for our use. */
 	m8xx_cpm_dpinit();
+#endif
 }
 
 /* We used to do this earlier, but have to postpone as long as possible
@@ -296,6 +303,7 @@ cpm_setbrg(uint brg, uint rate)
 		             CPM_BRG_EN | CPM_BRG_DIV16);
 }
 
+#ifndef CONFIG_PPC_CPM_NEW_BINDING
 /*
  * dpalloc / dpfree bits.
  */
@@ -397,6 +405,7 @@ uint cpm_dpram_phys(u8 *addr)
 	return (dpram_pbase + (uint)(addr - dpram_vbase));
 }
 EXPORT_SYMBOL(cpm_dpram_phys);
+#endif /* !CONFIG_PPC_CPM_NEW_BINDING */
 
 struct cpm_ioport16 {
 	__be16 dir, par, sor, dat, intr;
diff --git a/arch/powerpc/sysdev/cpm2_common.c b/arch/powerpc/sysdev/cpm2_common.c
index fc4c995..859362f 100644
--- a/arch/powerpc/sysdev/cpm2_common.c
+++ b/arch/powerpc/sysdev/cpm2_common.c
@@ -46,7 +46,10 @@
 
 #include <sysdev/fsl_soc.h>
 
+#ifndef CONFIG_PPC_CPM_NEW_BINDING
 static void cpm2_dpinit(void);
+#endif
+
 cpm_cpm2_t __iomem *cpmp; /* Pointer to comm processor space */
 
 /* We allocate this here because it is used almost exclusively for
@@ -69,7 +72,11 @@ cpm2_reset(void)
 
 	/* Reclaim the DP memory for our use.
 	 */
+#ifdef CONFIG_PPC_CPM_NEW_BINDING
+	cpm_muram_init();
+#else
 	cpm2_dpinit();
+#endif
 
 	/* Tell everyone where the comm processor resides.
 	 */
@@ -316,6 +323,7 @@ int cpm2_smc_clk_setup(enum cpm_clk_target target, int clock)
 	return ret;
 }
 
+#ifndef CONFIG_PPC_CPM_NEW_BINDING
 /*
  * dpalloc / dpfree bits.
  */
@@ -328,28 +336,6 @@ static u8 __iomem *im_dprambase;
 
 static void cpm2_dpinit(void)
 {
-	struct resource r;
-
-#ifdef CONFIG_PPC_CPM_NEW_BINDING
-	struct device_node *np;
-
-	np = of_find_compatible_node(NULL, NULL, "fsl,cpm2");
-	if (!np)
-		panic("Cannot find CPM2 node");
-
-	if (of_address_to_resource(np, 1, &r))
-		panic("Cannot get CPM2 resource 1");
-
-	of_node_put(np);
-#else
-	r.start = CPM_MAP_ADDR;
-	r.end = r.start + CPM_DATAONLY_BASE + CPM_DATAONLY_SIZE - 1;
-#endif
-
-	im_dprambase = ioremap(r.start, r.end - r.start + 1);
-	if (!im_dprambase)
-		panic("Cannot map DPRAM");
-
 	spin_lock_init(&cpm_dpmem_lock);
 
 	/* initialize the info header */
@@ -358,13 +344,15 @@ static void cpm2_dpinit(void)
 			sizeof(cpm_boot_dpmem_rh_block[0]),
 			cpm_boot_dpmem_rh_block);
 
+	im_dprambase = cpm2_immr;
+
 	/* Attach the usable dpmem area */
 	/* XXX: This is actually crap. CPM_DATAONLY_BASE and
 	 * CPM_DATAONLY_SIZE is only a subset of the available dpram. It
 	 * varies with the processor and the microcode patches activated.
 	 * But the following should be at least safe.
 	 */
-	rh_attach_region(&cpm_dpmem_info, 0, r.end - r.start + 1);
+	rh_attach_region(&cpm_dpmem_info, CPM_DATAONLY_BASE, CPM_DATAONLY_SIZE);
 }
 
 /* This function returns an index into the DPRAM area.
@@ -422,6 +410,7 @@ void *cpm_dpram_addr(unsigned long offset)
 	return (void *)(im_dprambase + offset);
 }
 EXPORT_SYMBOL(cpm_dpram_addr);
+#endif /* !CONFIG_PPC_CPM_NEW_BINDING */
 
 struct cpm2_ioports {
 	u32 dir, par, sor, odr, dat;
diff --git a/arch/powerpc/sysdev/cpm_common.c b/arch/powerpc/sysdev/cpm_common.c
index 9daa6ac..66c8ad4 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 */