arch/arm/include/asm/arch_timer.h

   1 #ifndef __ASMARM_ARCH_TIMER_H
   2 #define __ASMARM_ARCH_TIMER_H
   3
   4 #include <asm/barrier.h>
   5 #include <asm/errno.h>
   6 #include <linux/clocksource.h>
   7 #include <linux/init.h>
   8 #include <linux/types.h>
   9
  10 #include <clocksource/arm_arch_timer.h>
  11
  12 #ifdef CONFIG_ARM_ARCH_TIMER
  13 int arch_timer_arch_init(void);
  14
  15 /*
  16  * These register accessors are marked inline so the compiler can
  17  * nicely work out which register we want, and chuck away the rest of
  18  * the code. At least it does so with a recent GCC (4.6.3).
  19  */
  20 static inline void arch_timer_reg_write(const int access, const int reg, u32 val)
  21 {
  22         if (access == ARCH_TIMER_PHYS_ACCESS) {
  23                 switch (reg) {
  24                 case ARCH_TIMER_REG_CTRL:
  25                         asm volatile("mcr p15, 0, %0, c14, c2, 1" : : "r" (val));
  26                         break;
  27                 case ARCH_TIMER_REG_TVAL:
  28                         asm volatile("mcr p15, 0, %0, c14, c2, 0" : : "r" (val));
  29                         break;
  30                 }
  31         }
  32
  33         if (access == ARCH_TIMER_VIRT_ACCESS) {
  34                 switch (reg) {
  35                 case ARCH_TIMER_REG_CTRL:
  36                         asm volatile("mcr p15, 0, %0, c14, c3, 1" : : "r" (val));
  37                         break;
  38                 case ARCH_TIMER_REG_TVAL:
  39                         asm volatile("mcr p15, 0, %0, c14, c3, 0" : : "r" (val));
  40                         break;
  41                 }
  42         }
  43
  44         isb();
  45 }
  46
  47 static inline u32 arch_timer_reg_read(const int access, const int reg)
  48 {
  49         u32 val = 0;
  50
  51         if (access == ARCH_TIMER_PHYS_ACCESS) {
  52                 switch (reg) {
  53                 case ARCH_TIMER_REG_CTRL:
  54                         asm volatile("mrc p15, 0, %0, c14, c2, 1" : "=r" (val));
  55                         break;
  56                 case ARCH_TIMER_REG_TVAL:
  57                         asm volatile("mrc p15, 0, %0, c14, c2, 0" : "=r" (val));
  58                         break;
  59                 }
  60         }
  61
  62         if (access == ARCH_TIMER_VIRT_ACCESS) {
  63                 switch (reg) {
  64                 case ARCH_TIMER_REG_CTRL:
  65                         asm volatile("mrc p15, 0, %0, c14, c3, 1" : "=r" (val));
  66                         break;
  67                 case ARCH_TIMER_REG_TVAL:
  68                         asm volatile("mrc p15, 0, %0, c14, c3, 0" : "=r" (val));
  69                         break;
  70                 }
  71         }
  72
  73         return val;
  74 }
  75
  76 static inline u32 arch_timer_get_cntfrq(void)
  77 {
  78         u32 val;
  79         asm volatile("mrc p15, 0, %0, c14, c0, 0" : "=r" (val));
  80         return val;
  81 }
  82
  83 static inline u64 arch_counter_get_cntvct(void)
  84 {
  85         u64 cval;
  86
  87         isb();
  88         asm volatile("mrrc p15, 1, %Q0, %R0, c14" : "=r" (cval));
  89         return cval;
  90 }
  91
  92 static inline void arch_counter_set_user_access(void)
  93 {
  94         u32 cntkctl;
  95
  96         asm volatile("mrc p15, 0, %0, c14, c1, 0" : "=r" (cntkctl));
  97
  98         /* disable user access to everything */
  99         cntkctl &= ~((3 << 8) | (7 << 0));
 100
 101         asm volatile("mcr p15, 0, %0, c14, c1, 0" : : "r" (cntkctl));
 102 }
 103 #endif
 104
 105 #endif