arch/metag/kernel/core_reg.c

   1 /*
   2  *  Support for reading and writing Meta core internal registers.
   3  *
   4  *  Copyright (C) 2011 Imagination Technologies Ltd.
   5  *
   6  */
   7
   8 #include <linux/delay.h>
   9 #include <linux/export.h>
  10
  11 #include <asm/core_reg.h>
  12 #include <asm/global_lock.h>
  13 #include <asm/hwthread.h>
  14 #include <asm/io.h>
  15 #include <asm/metag_mem.h>
  16 #include <asm/metag_regs.h>
  17
  18 #define UNIT_BIT_MASK           TXUXXRXRQ_UXX_BITS
  19 #define REG_BIT_MASK            TXUXXRXRQ_RX_BITS
  20 #define THREAD_BIT_MASK         TXUXXRXRQ_TX_BITS
  21
  22 #define UNIT_SHIFTS             TXUXXRXRQ_UXX_S
  23 #define REG_SHIFTS              TXUXXRXRQ_RX_S
  24 #define THREAD_SHIFTS           TXUXXRXRQ_TX_S
  25
  26 #define UNIT_VAL(x)             (((x) << UNIT_SHIFTS) & UNIT_BIT_MASK)
  27 #define REG_VAL(x)              (((x) << REG_SHIFTS) & REG_BIT_MASK)
  28 #define THREAD_VAL(x)           (((x) << THREAD_SHIFTS) & THREAD_BIT_MASK)
  29
  30 /*
  31  * core_reg_write() - modify the content of a register in a core unit.
  32  * @unit:       The unit to be modified.
  33  * @reg:        Register number within the unit.
  34  * @thread:     The thread we want to access.
  35  * @val:        The new value to write.
  36  *
  37  * Check asm/metag_regs.h for a list/defines of supported units (ie: TXUPC_ID,
  38  * TXUTR_ID, etc), and regnums within the units (ie: TXMASKI_REGNUM,
  39  * TXPOLLI_REGNUM, etc).
  40  */
  41 void core_reg_write(int unit, int reg, int thread, unsigned int val)
  42 {
  43         unsigned long flags;
  44
  45         /* TXUCT_ID has its own memory mapped registers */
  46         if (unit == TXUCT_ID) {
  47                 void __iomem *cu_reg = __CU_addr(thread, reg);
  48                 metag_out32(val, cu_reg);
  49                 return;
  50         }
  51
  52         __global_lock2(flags);
  53
  54         /* wait for ready */
  55         while (!(metag_in32(TXUXXRXRQ) & TXUXXRXRQ_DREADY_BIT))
  56                 udelay(10);
  57
  58         /* set the value to write */
  59         metag_out32(val, TXUXXRXDT);
  60
  61         /* set the register to write */
  62         val = UNIT_VAL(unit) | REG_VAL(reg) | THREAD_VAL(thread);
  63         metag_out32(val, TXUXXRXRQ);
  64
  65         /* wait for finish */
  66         while (!(metag_in32(TXUXXRXRQ) & TXUXXRXRQ_DREADY_BIT))
  67                 udelay(10);
  68
  69         __global_unlock2(flags);
  70 }
  71 EXPORT_SYMBOL(core_reg_write);
  72
  73 /*
  74  * core_reg_read() - read the content of a register in a core unit.
  75  * @unit:       The unit to be modified.
  76  * @reg:        Register number within the unit.
  77  * @thread:     The thread we want to access.
  78  *
  79  * Check asm/metag_regs.h for a list/defines of supported units (ie: TXUPC_ID,
  80  * TXUTR_ID, etc), and regnums within the units (ie: TXMASKI_REGNUM,
  81  * TXPOLLI_REGNUM, etc).
  82  */
  83 unsigned int core_reg_read(int unit, int reg, int thread)
  84 {
  85         unsigned long flags;
  86         unsigned int val;
  87
  88         /* TXUCT_ID has its own memory mapped registers */
  89         if (unit == TXUCT_ID) {
  90                 void __iomem *cu_reg = __CU_addr(thread, reg);
  91                 val = metag_in32(cu_reg);
  92                 return val;
  93         }
  94
  95         __global_lock2(flags);
  96
  97         /* wait for ready */
  98         while (!(metag_in32(TXUXXRXRQ) & TXUXXRXRQ_DREADY_BIT))
  99                 udelay(10);
 100
 101         /* set the register to read */
 102         val = (UNIT_VAL(unit) | REG_VAL(reg) | THREAD_VAL(thread) |
 103                                                         TXUXXRXRQ_RDnWR_BIT);
 104         metag_out32(val, TXUXXRXRQ);
 105
 106         /* wait for finish */
 107         while (!(metag_in32(TXUXXRXRQ) & TXUXXRXRQ_DREADY_BIT))
 108                 udelay(10);
 109
 110         /* read the register value */
 111         val = metag_in32(TXUXXRXDT);
 112
 113         __global_unlock2(flags);
 114
 115         return val;
 116 }
 117 EXPORT_SYMBOL(core_reg_read);