1Interface for registering and calling firmware-specific operations for ARM. 2---- 3Written by Tomasz Figa <t.figa@samsung.com> 4 5Some boards are running with secure firmware running in TrustZone secure 6world, which changes the way some things have to be initialized. This makes 7a need to provide an interface for such platforms to specify available firmware 8operations and call them when needed. 9 10Firmware operations can be specified using struct firmware_ops 11 12 struct firmware_ops { 13 /* 14 * Enters CPU idle mode 15 */ 16 int (*do_idle)(void); 17 /* 18 * Sets boot address of specified physical CPU 19 */ 20 int (*set_cpu_boot_addr)(int cpu, unsigned long boot_addr); 21 /* 22 * Boots specified physical CPU 23 */ 24 int (*cpu_boot)(int cpu); 25 /* 26 * Initializes L2 cache 27 */ 28 int (*l2x0_init)(void); 29 }; 30 31and then registered with register_firmware_ops function 32 33 void register_firmware_ops(const struct firmware_ops *ops) 34 35the ops pointer must be non-NULL. 36 37There is a default, empty set of operations provided, so there is no need to 38set anything if platform does not require firmware operations. 39 40To call a firmware operation, a helper macro is provided 41 42 #define call_firmware_op(op, ...) \ 43 ((firmware_ops->op) ? firmware_ops->op(__VA_ARGS__) : (-ENOSYS)) 44 45the macro checks if the operation is provided and calls it or otherwise returns 46-ENOSYS to signal that given operation is not available (for example, to allow 47fallback to legacy operation). 48 49Example of registering firmware operations: 50 51 /* board file */ 52 53 static int platformX_do_idle(void) 54 { 55 /* tell platformX firmware to enter idle */ 56 return 0; 57 } 58 59 static int platformX_cpu_boot(int i) 60 { 61 /* tell platformX firmware to boot CPU i */ 62 return 0; 63 } 64 65 static const struct firmware_ops platformX_firmware_ops = { 66 .do_idle = exynos_do_idle, 67 .cpu_boot = exynos_cpu_boot, 68 /* other operations not available on platformX */ 69 }; 70 71 /* init_early callback of machine descriptor */ 72 static void __init board_init_early(void) 73 { 74 register_firmware_ops(&platformX_firmware_ops); 75 } 76 77Example of using a firmware operation: 78 79 /* some platform code, e.g. SMP initialization */ 80 81 __raw_writel(virt_to_phys(exynos4_secondary_startup), 82 CPU1_BOOT_REG); 83 84 /* Call Exynos specific smc call */ 85 if (call_firmware_op(cpu_boot, cpu) == -ENOSYS) 86 cpu_boot_legacy(...); /* Try legacy way */ 87 88 gic_raise_softirq(cpumask_of(cpu), 1); 89