lib/libgpio/clkconf.c

   1 /* kernel headers */
   2 #include <minix/syslib.h>
   3 #include <minix/drvlib.h>
   4 #include <minix/log.h>
   5 #include <minix/mmio.h>
   6
   7 /* system headers */
   8 #include <sys/mman.h>
   9 #include <sys/types.h>
  10
  11 /* usr headers */
  12 #include <stdio.h>
  13 #include <stdlib.h>
  14 #include <stdarg.h>
  15 #include <string.h>
  16 #include <errno.h>
  17 #include <assert.h>
  18
  19 /* local headers */
  20 #include "clkconf.h"
  21
  22 /* used for logging */
  23 static struct log log = {
  24         .name = "omap_clkconf",
  25         .log_level = LEVEL_INFO,
  26         .log_func = default_log
  27 };
  28
  29 #define CM_BASE 0x48004000
  30 static u32_t base = 0;
  31 static u32_t use_count = 0;
  32
  33 int
  34 clkconf_init()
  35 {
  36         use_count++;
  37
  38         if (base != 0) {
  39                 /* when used in a library we can't guaranty we only call this
  40                  * method once */
  41                 log_trace(&log, "Called %d times\n", use_count);
  42                 return OK;
  43         }
  44         struct minix_mem_range mr;
  45         mr.mr_base = CM_BASE;
  46         mr.mr_limit = CM_BASE + 0x1000;
  47
  48         if (sys_privctl(SELF, SYS_PRIV_ADD_MEM, &mr) != 0) {
  49                 log_warn(&log, "Unable to request permission to map memory\n");
  50                 return EPERM;
  51         }
  52
  53         base = (uint32_t) vm_map_phys(SELF, (void *) CM_BASE, 0x1000);
  54
  55         if (base == (uint32_t) MAP_FAILED) {
  56                 log_warn(&log, "Unable to map GPIO memory\n");
  57                 return EPERM;
  58         }
  59         return OK;
  60 }
  61
  62 int
  63 clkconf_set(u32_t clk, u32_t mask, u32_t value)
  64 {
  65         set32(base + clk, mask, value);
  66         return OK;
  67 }
  68
  69 int
  70 clkconf_release()
  71 {
  72         assert(use_count > 0);
  73         use_count--;
  74         if (use_count == 0) {
  75                 vm_unmap_phys(SELF, (void *) base, 0x1000);
  76         }
  77         return OK;
  78 }