git.mutantstargoat.com Git - rpikern/blob - src/rpi.c

   1 #include "rpi.h"
   2 #include "asm.h"
   3
   4 #define IOREG(offs)             (*(volatile uint32_t*)(rpi_iobase | offs))
   5
   6 /* System timer */
   7 #define STM_CTL_REG             IOREG(0x3000)
   8 #define STM_STAT_REG    STM_CTL_REG
   9 #define STM_LCNT_REG    IOREG(0x3004)
  10 #define STM_HCNT_REG    IOREG(0x3008)
  11 #define STM_CMP0_REG    IOREG(0x300c)
  12 #define STM_CMP1_REG    IOREG(0x3010)
  13 #define STM_CMP2_REG    IOREG(0x3014)
  14 #define STM_CMP3_REG    IOREG(0x3018)
  15
  16 #define STMCTL_M0               1
  17 #define STMCTL_M1               2
  18 #define STMCTL_M2               4
  19 #define STMCTL_M3               8
  20
  21 /* TIMER */
  22 #define TM_LOAD_REG             IOREG(0xb400)
  23 #define TM_VALUE_REG    IOREG(0xb404)
  24 #define TM_CTL_REG              IOREG(0xb408)
  25 #define TM_ICLR_REG             IOREG(0xb40c)
  26 #define TM_IRAW_REG             IOREG(0xb410)
  27 #define TM_IMSK_REG             IOREG(0xb414)
  28 #define TM_RELOAD_REG   IOREG(0xb418)
  29 #define TM_PREDIV_REG   IOREG(0xb41c)
  30 #define TM_COUNT_REG    IOREG(0xb420)
  31
  32 #define TMCTL_23BIT             0x000002
  33 #define TMCTL_DIV16             0x000004
  34 #define TMCTL_DIV256    0x000008
  35 #define TMCTL_DIV1              0x00000c
  36 #define TMCTL_IEN               0x000020
  37 #define TMCTL_EN                0x000080
  38 #define TMCTL_DBGHALT   0x000100
  39 #define TMCTL_CNTEN             0x000200
  40
  41 #define TMCTL_PRESCALER(x)      (((uint32_t)(x) & 0xff) << 16)
  42
  43
  44 /* MAILBOX */
  45 #define MBOX_READ_REG   IOREG(0xb880)
  46 #define MBOX_POLL_REG   IOREG(0xb890)
  47 #define MBOX_SENDER_REG IOREG(0xb894)
  48 #define MBOX_STATUS_REG IOREG(0xb898)
  49 #define MBOX_CFG_REG    IOREG(0xb89c)
  50 #define MBOX_WRITE_REG  IOREG(0xb8a0)
  51
  52 /* the full bit is set when there's no space to append messages */
  53 #define MBOX_STAT_FULL  0x80000000
  54 /* the empty bit is set when there are no pending messages to be read */
  55 #define MBOX_STAT_EMPTY 0x40000000
  56
  57 static int detect(void);
  58
  59 int rpi_model;
  60 uint32_t rpi_iobase;
  61 uint32_t rpi_memsize, rpi_vc_memsize;
  62
  63 void rpi_init(void)
  64 {
  65         if((rpi_model = detect()) == -1) {
  66                 for(;;) halt_cpu();
  67         }
  68
  69         /* TODO */
  70 }
  71
  72 static int detect(void)
  73 {
  74         int i, j;
  75         uint32_t tm0, tm1;
  76         static uint32_t base[] = {0x20000000, 0x3f000000, 0xfe000000};
  77
  78         for(i=0; i<3; i++) {
  79                 rpi_iobase = base[i];
  80                 tm0 = STM_LCNT_REG;
  81                 for(j=0; j<256; j++) {
  82                         tm1 = STM_LCNT_REG;
  83                 }
  84                 if(tm0 != tm1) {
  85                         return i + 1;
  86                 }
  87         }
  88         return -1;
  89 }
  90
  91
  92 void rpi_mbox_send(int chan, uint32_t msg)
  93 {
  94         while(MBOX_STATUS_REG & MBOX_STAT_FULL);
  95         MBOX_WRITE_REG = (msg & 0xfffffff0) | chan;
  96 }
  97
  98 uint32_t rpi_mbox_recv(int chan)
  99 {
 100         uint32_t msg;
 101         do {
 102                 while(MBOX_STATUS_REG & MBOX_STAT_EMPTY);
 103                 msg = MBOX_READ_REG;
 104         } while((msg & 0xf) != chan);
 105         return msg & 0xfffffff0;
 106 }
 107
 108 int rpi_mbox_pending(int chan)
 109 {
 110         return (MBOX_STATUS_REG & MBOX_STAT_EMPTY) == 0;
 111 }