From 0b05ac6e24807f0c26f763b3a546c0bcbf84125f Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Mon, 4 Apr 2011 13:46:58 +1000 Subject: powerpc/xics: Rewrite XICS driver This is a significant rework of the XICS driver, too significant to conveniently break it up into a series of smaller patches to be honest. The driver is moved to a more generic location to allow new platforms to use it, and is broken up into separate ICP and ICS "backends". For now we have the native and "hypervisor" ICP backends and one common RTAS ICS backend. The driver supports one ICP backend instanciation, and many ICS ones, in order to accomodate future platforms with multiple possibly different interrupt "sources" mechanisms. Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/sysdev/Makefile | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'arch/powerpc/sysdev/Makefile') diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile index 1e0c933ef77..9516e759857 100644 --- a/arch/powerpc/sysdev/Makefile +++ b/arch/powerpc/sysdev/Makefile @@ -57,3 +57,7 @@ obj-$(CONFIG_PPC_MPC52xx) += mpc5xxx_clocks.o ifeq ($(CONFIG_SUSPEND),y) obj-$(CONFIG_6xx) += 6xx-suspend.o endif + +subdir-ccflags-$(CONFIG_PPC_WERROR) := -Werror + +obj-$(CONFIG_PPC_XICS) += xics/ -- cgit v1.2.3-70-g09d2 From ab814b938d1d372bd2ac6268c15d4e0e6a5245c4 Mon Sep 17 00:00:00 2001 From: Benjamin Herrenschmidt Date: Thu, 14 Apr 2011 22:31:58 +0000 Subject: powerpc: Add SCOM infrastructure SCOM is a side-band configuration bus implemented on some processors. This code provides a way for code to map and operate on devices via SCOM, while the details of how that is implemented is left up to a SCOM "controller" in the platform code. Signed-off-by: Benjamin Herrenschmidt Signed-off-by: Michael Ellerman Signed-off-by: Benjamin Herrenschmidt --- arch/powerpc/include/asm/scom.h | 156 ++++++++++++++++++++++++++++++++ arch/powerpc/sysdev/Kconfig | 7 ++ arch/powerpc/sysdev/Makefile | 2 + arch/powerpc/sysdev/scom.c | 192 ++++++++++++++++++++++++++++++++++++++++ 4 files changed, 357 insertions(+) create mode 100644 arch/powerpc/include/asm/scom.h create mode 100644 arch/powerpc/sysdev/scom.c (limited to 'arch/powerpc/sysdev/Makefile') diff --git a/arch/powerpc/include/asm/scom.h b/arch/powerpc/include/asm/scom.h new file mode 100644 index 00000000000..0cabfd7bc2d --- /dev/null +++ b/arch/powerpc/include/asm/scom.h @@ -0,0 +1,156 @@ +/* + * Copyright 2010 Benjamin Herrenschmidt, IBM Corp + * + * 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 */ diff --git a/arch/powerpc/sysdev/Kconfig b/arch/powerpc/sysdev/Kconfig index cfc18770af7..d775fd148d1 100644 --- a/arch/powerpc/sysdev/Kconfig +++ b/arch/powerpc/sysdev/Kconfig @@ -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 diff --git a/arch/powerpc/sysdev/Makefile b/arch/powerpc/sysdev/Makefile index 9516e759857..6076e0074a8 100644 --- a/arch/powerpc/sysdev/Makefile +++ b/arch/powerpc/sysdev/Makefile @@ -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/ diff --git a/arch/powerpc/sysdev/scom.c b/arch/powerpc/sysdev/scom.c new file mode 100644 index 00000000000..b2593ce30c9 --- /dev/null +++ b/arch/powerpc/sysdev/scom.c @@ -0,0 +1,192 @@ +/* + * Copyright 2010 Benjamin Herrenschmidt, IBM Corp + * + * 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 +#include +#include +#include +#include + +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 */ -- cgit v1.2.3-70-g09d2