minix/lib/libclkconf/clkconf.c
Thomas Cort ba92d5219d clkconf: move clkconf from libgpio to it's own lib
Clock configuration will be needed by other/future subsystems such as i2c.
Extract the functionality from libgpio and put it into it's own library.

Change-Id: I6f6de0b3fb4d305ddfeac74123b78c983d1318dd
2013-06-18 09:09:23 +02:00

76 lines
1.4 KiB
C

/* kernel headers */
#include <minix/syslib.h>
#include <minix/drvlib.h>
#include <minix/log.h>
#include <minix/mmio.h>
#include <minix/clkconf.h>
/* system headers */
#include <sys/mman.h>
#include <sys/types.h>
/* usr headers */
#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>
#include <string.h>
#include <errno.h>
#include <assert.h>
/* used for logging */
static struct log log = {
.name = "omap_clkconf",
.log_level = LEVEL_INFO,
.log_func = default_log
};
#define CM_BASE 0x48004000
static u32_t base = 0;
static u32_t use_count = 0;
int
clkconf_init()
{
use_count++;
if (base != 0) {
/* when used in a library we can't guaranty we only call this
* method once */
log_trace(&log, "Called %d times\n", use_count);
return OK;
}
struct minix_mem_range mr;
mr.mr_base = CM_BASE;
mr.mr_limit = CM_BASE + 0x1000;
if (sys_privctl(SELF, SYS_PRIV_ADD_MEM, &mr) != 0) {
log_warn(&log, "Unable to request permission to map memory\n");
return EPERM;
}
base = (uint32_t) vm_map_phys(SELF, (void *) CM_BASE, 0x1000);
if (base == (uint32_t) MAP_FAILED) {
log_warn(&log, "Unable to map GPIO memory\n");
return EPERM;
}
return OK;
}
int
clkconf_set(u32_t clk, u32_t mask, u32_t value)
{
set32(base + clk, mask, value);
return OK;
}
int
clkconf_release()
{
assert(use_count > 0);
use_count--;
if (use_count == 0) {
vm_unmap_phys(SELF, (void *) base, 0x1000);
}
return OK;
}