powerpc: Add SCOM infrastructure (ab814b93) · Commits · 戴 / test

arch/powerpc/include/asm/scom.h

0 → 100644

+156 −0

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		/*
		* Copyright 2010 Benjamin Herrenschmidt, IBM Corp
		* <benh@kernel.crashing.org>
		* and David Gibson, IBM Corporation.
		*
		* 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
		*/

		#ifndef _ASM_POWERPC_SCOM_H
		#define _ASM_POWERPC_SCOM_H

		#ifdef __KERNEL__
		#ifndef __ASSEMBLY__
		#ifdef CONFIG_PPC_SCOM

		/*
		* The SCOM bus is a sideband bus used for accessing various internal
		* registers of the processor or the chipset. The implementation details
		* differ between processors and platforms, and the access method as
		* well.
		*
		* This API allows to "map" ranges of SCOM register numbers associated
		* with a given SCOM controller. The later must be represented by a
		* device node, though some implementations might support NULL if there
		* is no possible ambiguity
		*
		* Then, scom_read/scom_write can be used to accesses registers inside
		* that range. The argument passed is a register number relative to
		* the beginning of the range mapped.
		*/

		typedef void *scom_map_t;

		/* Value for an invalid SCOM map */
		#define SCOM_MAP_INVALID (NULL)

		/* The scom_controller data structure is what the platform passes
		* to the core code in scom_init, it provides the actual implementation
		* of all the SCOM functions
		*/
		struct scom_controller {
		scom_map_t (map)(struct device_node ctrl_dev, u64 reg, u64 count);
		void (*unmap)(scom_map_t map);

		u64 (*read)(scom_map_t map, u32 reg);
		void (*write)(scom_map_t map, u32 reg, u64 value);
		};

		extern const struct scom_controller *scom_controller;

		/**
		* scom_init - Initialize the SCOM backend, called by the platform
		* @controller: The platform SCOM controller
		*/
		static inline void scom_init(const struct scom_controller *controller)
		{
		scom_controller = controller;
		}

		/**
		* scom_map_ok - Test is a SCOM mapping is successful
		* @map: The result of scom_map to test
		*/
		static inline int scom_map_ok(scom_map_t map)
		{
		return map != SCOM_MAP_INVALID;
		}

		/**
		* scom_map - Map a block of SCOM registers
		* @ctrl_dev: Device node of the SCOM controller
		* some implementations allow NULL here
		* @reg: first SCOM register to map
		* @count: Number of SCOM registers to map
		*/

		static inline scom_map_t scom_map(struct device_node *ctrl_dev,
		u64 reg, u64 count)
		{
		return scom_controller->map(ctrl_dev, reg, count);
		}

		/**
		* scom_find_parent - Find the SCOM controller for a device
		* @dev: OF node of the device
		*
		* This is not meant for general usage, but in combination with
		* scom_map() allows to map registers not represented by the
		* device own scom-reg property. Useful for applying HW workarounds
		* on things not properly represented in the device-tree for example.
		*/
		struct device_node scom_find_parent(struct device_node dev);


		/**
		* scom_map_device - Map a device's block of SCOM registers
		* @dev: OF node of the device
		* @index: Register bank index (index in "scom-reg" property)
		*
		* This function will use the device-tree binding for SCOM which
		* is to follow "scom-parent" properties until it finds a node with
		* a "scom-controller" property to find the controller. It will then
		* use the "scom-reg" property which is made of reg/count pairs,
		* each of them having a size defined by the controller's #scom-cells
		* property
		*/
		extern scom_map_t scom_map_device(struct device_node *dev, int index);


		/**
		* scom_unmap - Unmap a block of SCOM registers
		* @map: Result of scom_map is to be unmapped
		*/
		static inline void scom_unmap(scom_map_t map)
		{
		if (scom_map_ok(map))
		scom_controller->unmap(map);
		}

		/**
		* scom_read - Read a SCOM register
		* @map: Result of scom_map
		* @reg: Register index within that map
		*/
		static inline u64 scom_read(scom_map_t map, u32 reg)
		{
		return scom_controller->read(map, reg);
		}

		/**
		* scom_write - Write to a SCOM register
		* @map: Result of scom_map
		* @reg: Register index within that map
		* @value: Value to write
		*/
		static inline void scom_write(scom_map_t map, u32 reg, u64 value)
		{
		scom_controller->write(map, reg, value);
		}

		#endif /* CONFIG_PPC_SCOM */
		#endif /* __ASSEMBLY__ */
		#endif /* __KERNEL__ */
		#endif /* _ASM_POWERPC_SCOM_H */

arch/powerpc/sysdev/Kconfig

+7 −0

Original line number	Diff line number	Diff line
		@@ -15,3 +15,10 @@ config PPC_MSI_BITMAP

		source "arch/powerpc/sysdev/xics/Kconfig"

		config PPC_SCOM
		bool

		config SCOM_DEBUGFS
		bool "Expose SCOM controllers via debugfs"
		depends on PPC_SCOM
		default n

arch/powerpc/sysdev/Makefile

+2 −0

Original line number	Diff line number	Diff line
		@@ -58,6 +58,8 @@ ifeq ($(CONFIG_SUSPEND),y)
		obj-$(CONFIG_6xx) += 6xx-suspend.o
		endif

		obj-$(CONFIG_PPC_SCOM) += scom.o

		subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror

		obj-$(CONFIG_PPC_XICS) += xics/

arch/powerpc/sysdev/scom.c

0 → 100644

+192 −0

Original line number	Diff line number	Diff line
		/*
		* Copyright 2010 Benjamin Herrenschmidt, IBM Corp
		* <benh@kernel.crashing.org>
		* and David Gibson, IBM Corporation.
		*
		* 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
		*/

		#include <linux/kernel.h>
		#include <linux/debugfs.h>
		#include <linux/slab.h>
		#include <asm/prom.h>
		#include <asm/scom.h>

		const struct scom_controller *scom_controller;
		EXPORT_SYMBOL_GPL(scom_controller);

		struct device_node scom_find_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, "scom-controller", NULL))
		break;
		p = of_get_property(par, "scom-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;
		}
		EXPORT_SYMBOL_GPL(scom_find_parent);

		scom_map_t scom_map_device(struct device_node *dev, int index)
		{
		struct device_node *parent;
		unsigned int cells, size;
		const u32 *prop;
		u64 reg, cnt;
		scom_map_t ret;

		parent = scom_find_parent(dev);

		if (parent == NULL)
		return 0;

		prop = of_get_property(parent, "#scom-cells", NULL);
		cells = prop ? *prop : 1;

		prop = of_get_property(dev, "scom-reg", &size);
		if (!prop)
		return 0;
		size >>= 2;

		if (index >= (size / (2*cells)))
		return 0;

		reg = of_read_number(&prop[index * cells * 2], cells);
		cnt = of_read_number(&prop[index * cells * 2 + cells], cells);

		ret = scom_map(parent, reg, cnt);
		of_node_put(parent);

		return ret;
		}
		EXPORT_SYMBOL_GPL(scom_map_device);

		#ifdef CONFIG_SCOM_DEBUGFS
		struct scom_debug_entry {
		struct device_node *dn;
		unsigned long addr;
		scom_map_t map;
		spinlock_t lock;
		char name[8];
		struct debugfs_blob_wrapper blob;
		};

		static int scom_addr_set(void *data, u64 val)
		{
		struct scom_debug_entry *ent = data;

		ent->addr = 0;
		scom_unmap(ent->map);

		ent->map = scom_map(ent->dn, val, 1);
		if (scom_map_ok(ent->map))
		ent->addr = val;
		else
		return -EFAULT;

		return 0;
		}

		static int scom_addr_get(void data, u64 val)
		{
		struct scom_debug_entry *ent = data;
		*val = ent->addr;
		return 0;
		}
		DEFINE_SIMPLE_ATTRIBUTE(scom_addr_fops, scom_addr_get, scom_addr_set,
		"0x%llx\n");

		static int scom_val_set(void *data, u64 val)
		{
		struct scom_debug_entry *ent = data;

		if (!scom_map_ok(ent->map))
		return -EFAULT;

		scom_write(ent->map, 0, val);

		return 0;
		}

		static int scom_val_get(void data, u64 val)
		{
		struct scom_debug_entry *ent = data;

		if (!scom_map_ok(ent->map))
		return -EFAULT;

		*val = scom_read(ent->map, 0);
		return 0;
		}
		DEFINE_SIMPLE_ATTRIBUTE(scom_val_fops, scom_val_get, scom_val_set,
		"0x%llx\n");

		static int scom_debug_init_one(struct dentry root, struct device_node dn,
		int i)
		{
		struct scom_debug_entry *ent;
		struct dentry *dir;

		ent = kzalloc(sizeof(*ent), GFP_KERNEL);
		if (!ent)
		return -ENOMEM;

		ent->dn = of_node_get(dn);
		ent->map = SCOM_MAP_INVALID;
		spin_lock_init(&ent->lock);
		snprintf(ent->name, 8, "scom%d", i);
		ent->blob.data = dn->full_name;
		ent->blob.size = strlen(dn->full_name);

		dir = debugfs_create_dir(ent->name, root);
		if (!dir) {
		of_node_put(dn);
		kfree(ent);
		return -1;
		}

		debugfs_create_file("addr", 0600, dir, ent, &scom_addr_fops);
		debugfs_create_file("value", 0600, dir, ent, &scom_val_fops);
		debugfs_create_blob("path", 0400, dir, &ent->blob);

		return 0;
		}

		static int scom_debug_init(void)
		{
		struct device_node *dn;
		struct dentry *root;
		int i, rc;

		root = debugfs_create_dir("scom", powerpc_debugfs_root);
		if (!root)
		return -1;

		i = rc = 0;
		for_each_node_with_property(dn, "scom-controller")
		rc \|= scom_debug_init_one(root, dn, i++);

		return rc;
		}
		device_initcall(scom_debug_init);
		#endif /* CONFIG_SCOM_DEBUGFS */

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