diff options
| -rw-r--r-- | Documentation/arm/firmware.txt | 88 | ||||
| -rw-r--r-- | arch/arm/common/Makefile | 2 | ||||
| -rw-r--r-- | arch/arm/common/firmware.c | 18 | ||||
| -rw-r--r-- | arch/arm/include/asm/firmware.h | 66 |
4 files changed, 174 insertions, 0 deletions
diff --git a/Documentation/arm/firmware.txt b/Documentation/arm/firmware.txt new file mode 100644 index 0000000..c2e468f --- /dev/null +++ b/Documentation/arm/firmware.txt @@ -0,0 +1,88 @@ +Interface for registering and calling firmware-specific operations for ARM. +---- +Written by Tomasz Figa <t.figa@samsung.com> + +Some boards are running with secure firmware running in TrustZone secure +world, which changes the way some things have to be initialized. This makes +a need to provide an interface for such platforms to specify available firmware +operations and call them when needed. + +Firmware operations can be specified using struct firmware_ops + + struct firmware_ops { + /* + * Enters CPU idle mode + */ + int (*do_idle)(void); + /* + * Sets boot address of specified physical CPU + */ + int (*set_cpu_boot_addr)(int cpu, unsigned long boot_addr); + /* + * Boots specified physical CPU + */ + int (*cpu_boot)(int cpu); + /* + * Initializes L2 cache + */ + int (*l2x0_init)(void); + }; + +and then registered with register_firmware_ops function + + void register_firmware_ops(const struct firmware_ops *ops) + +the ops pointer must be non-NULL. + +There is a default, empty set of operations provided, so there is no need to +set anything if platform does not require firmware operations. + +To call a firmware operation, a helper macro is provided + + #define call_firmware_op(op, ...) \ + ((firmware_ops->op) ? firmware_ops->op(__VA_ARGS__) : (-ENOSYS)) + +the macro checks if the operation is provided and calls it or otherwise returns +-ENOSYS to signal that given operation is not available (for example, to allow +fallback to legacy operation). + +Example of registering firmware operations: + + /* board file */ + + static int platformX_do_idle(void) + { + /* tell platformX firmware to enter idle */ + return 0; + } + + static int platformX_cpu_boot(int i) + { + /* tell platformX firmware to boot CPU i */ + return 0; + } + + static const struct firmware_ops platformX_firmware_ops = { + .do_idle = exynos_do_idle, + .cpu_boot = exynos_cpu_boot, + /* other operations not available on platformX */ + }; + + /* init_early callback of machine descriptor */ + static void __init board_init_early(void) + { + register_firmware_ops(&platformX_firmware_ops); + } + +Example of using a firmware operation: + + /* some platform code, e.g. SMP initialization */ + + __raw_writel(virt_to_phys(exynos4_secondary_startup), + CPU1_BOOT_REG); + + /* Call Exynos specific smc call */ + if (call_firmware_op(cpu_boot, cpu) == -ENOSYS) + cpu_boot_legacy(...); /* Try legacy way */ + + gic_raise_softirq(cpumask_of(cpu), 1); diff --git a/arch/arm/common/Makefile b/arch/arm/common/Makefile index dc8dd0d..45f7eae 100644 --- a/arch/arm/common/Makefile +++ b/arch/arm/common/Makefile @@ -2,6 +2,8 @@ # Makefile for the linux kernel. # +obj-y += firmware.o + obj-$(CONFIG_ICST) += icst.o obj-$(CONFIG_SA1111) += sa1111.o obj-$(CONFIG_PCI_HOST_VIA82C505) += via82c505.o diff --git a/arch/arm/common/firmware.c b/arch/arm/common/firmware.c new file mode 100644 index 0000000..27ddccb --- /dev/null +++ b/arch/arm/common/firmware.c @@ -0,0 +1,18 @@ +/* + * Copyright (C) 2012 Samsung Electronics. + * Kyungmin Park <kyungmin.park@samsung.com> + * Tomasz Figa <t.figa@samsung.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#include <linux/kernel.h> +#include <linux/suspend.h> + +#include <asm/firmware.h> + +static const struct firmware_ops default_firmware_ops; + +const struct firmware_ops *firmware_ops = &default_firmware_ops; diff --git a/arch/arm/include/asm/firmware.h b/arch/arm/include/asm/firmware.h new file mode 100644 index 0000000..1563130 --- /dev/null +++ b/arch/arm/include/asm/firmware.h @@ -0,0 +1,66 @@ +/* + * Copyright (C) 2012 Samsung Electronics. + * Kyungmin Park <kyungmin.park@samsung.com> + * Tomasz Figa <t.figa@samsung.com> + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License version 2 as + * published by the Free Software Foundation. + */ + +#ifndef __ASM_ARM_FIRMWARE_H +#define __ASM_ARM_FIRMWARE_H + +#include <linux/bug.h> + +/* + * struct firmware_ops + * + * A structure to specify available firmware operations. + * + * A filled up structure can be registered with register_firmware_ops(). + */ +struct firmware_ops { + /* + * Enters CPU idle mode + */ + int (*do_idle)(void); + /* + * Sets boot address of specified physical CPU + */ + int (*set_cpu_boot_addr)(int cpu, unsigned long boot_addr); + /* + * Boots specified physical CPU + */ + int (*cpu_boot)(int cpu); + /* + * Initializes L2 cache + */ + int (*l2x0_init)(void); +}; + +/* Global pointer for current firmware_ops structure, can't be NULL. */ +extern const struct firmware_ops *firmware_ops; + +/* + * call_firmware_op(op, ...) + * + * Checks if firmware operation is present and calls it, + * otherwise returns -ENOSYS + */ +#define call_firmware_op(op, ...) \ + ((firmware_ops->op) ? firmware_ops->op(__VA_ARGS__) : (-ENOSYS)) + +/* + * register_firmware_ops(ops) + * + * A function to register platform firmware_ops struct. + */ +static inline void register_firmware_ops(const struct firmware_ops *ops) +{ + BUG_ON(!ops); + + firmware_ops = ops; +} + +#endif |
