diff options
author | Andrew Donnellan <ajd@linux.ibm.com> | 2019-05-09 08:11:15 +0300 |
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committer | Michael Ellerman <mpe@ellerman.id.au> | 2019-08-05 11:53:03 +0300 |
commit | 08a456aa643776757e07adfdebe7f7681117d144 (patch) | |
tree | ae477a0ad078276e74c99e5ee02b82b5bbeb56de /arch/powerpc/include/asm/scom.h | |
parent | 0df3e42167caaf9f8c7b64de3da40a459979afe8 (diff) | |
download | linux-08a456aa643776757e07adfdebe7f7681117d144.tar.xz |
powerpc/powernv: Move SCOM access code into powernv platform
The powernv platform is the only one that directly accesses SCOMs.
Move the support code to platforms/powernv, and get rid of the
PPC_SCOM Kconfig option, as SCOM support is always selected when
compiling for powernv.
This also means that the Kconfig item for CONFIG_SCOM_DEBUGFS will
show up in menuconfig in the platform menu, rather than at the root,
which is a much better location.
Signed-off-by: Andrew Donnellan <ajd@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20190509051119.7694-1-ajd@linux.ibm.com
Diffstat (limited to 'arch/powerpc/include/asm/scom.h')
-rw-r--r-- | arch/powerpc/include/asm/scom.h | 154 |
1 files changed, 0 insertions, 154 deletions
diff --git a/arch/powerpc/include/asm/scom.h b/arch/powerpc/include/asm/scom.h deleted file mode 100644 index 08c44396e54a..000000000000 --- a/arch/powerpc/include/asm/scom.h +++ /dev/null @@ -1,154 +0,0 @@ -/* SPDX-License-Identifier: GPL-2.0-or-later */ -/* - * Copyright 2010 Benjamin Herrenschmidt, IBM Corp - * <benh@kernel.crashing.org> - * and David Gibson, IBM Corporation. - */ - -#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); - - int (*read)(scom_map_t map, u64 reg, u64 *value); - int (*write)(scom_map_t map, u64 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 - * @value: Updated with the value read - * - * Returns 0 (success) or a negative error code - */ -static inline int scom_read(scom_map_t map, u64 reg, u64 *value) -{ - int rc; - - rc = scom_controller->read(map, reg, value); - if (rc) - *value = 0xfffffffffffffffful; - return rc; -} - -/** - * scom_write - Write to a SCOM register - * @map: Result of scom_map - * @reg: Register index within that map - * @value: Value to write - * - * Returns 0 (success) or a negative error code - */ -static inline int scom_write(scom_map_t map, u64 reg, u64 value) -{ - return scom_controller->write(map, reg, value); -} - - -#endif /* CONFIG_PPC_SCOM */ -#endif /* __ASSEMBLY__ */ -#endif /* __KERNEL__ */ -#endif /* _ASM_POWERPC_SCOM_H */ |