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/*
* GRUB -- GRand Unified Bootloader
* Copyright (C) 2016 Free Software Foundation, Inc.
*
* GRUB is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* GRUB is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with GRUB. If not, see <http://www.gnu.org/licenses/>.
*/
#include <grub/mm.h>
#include <grub/machine/kernel.h>
#include <grub/types.h>
#include <grub/err.h>
#include <grub/time.h>
#include <grub/fdtbus.h>
#include <grub/misc.h>
grub_uint64_t
grub_armv7_get_timer_value(void);
grub_uint32_t
grub_armv7_get_timer_frequency(void);
grub_uint32_t
grub_arm_pfr1(void);
static int have_timer = 0;
static volatile grub_uint32_t *sp804_regs;
static grub_uint64_t
sp804_get_time_ms (void)
{
static grub_uint32_t high, last_low;
grub_uint32_t low = ~sp804_regs[1];
if (last_low > low)
high++;
last_low = low;
return grub_divmod64 ((((grub_uint64_t) high) << 32) | low,
1000, 0);
}
static grub_err_t
sp804_attach(const struct grub_fdtbus_dev *dev)
{
if (have_timer)
return GRUB_ERR_NONE;
sp804_regs = grub_fdtbus_map_reg (dev, 0, 0);
if (!grub_fdtbus_is_mapping_valid (sp804_regs))
return grub_error (GRUB_ERR_IO, "could not map sp804: %p", sp804_regs);
grub_install_get_time_ms (sp804_get_time_ms);
have_timer = 1;
return GRUB_ERR_NONE;
}
struct grub_fdtbus_driver sp804 =
{
.compatible = "arm,sp804",
.attach = sp804_attach
};
static grub_uint32_t timer_frequency_in_khz;
static grub_uint64_t
generic_get_time_ms (void)
{
return grub_divmod64 (grub_armv7_get_timer_value(), timer_frequency_in_khz, 0);
}
static int
try_generic_timer (void)
{
if (((grub_arm_pfr1 () >> 16) & 0xf) != 1)
return 0;
grub_printf ("freq = %x\n", grub_armv7_get_timer_frequency());
timer_frequency_in_khz = 0x016e3600 / 1000; //grub_armv7_get_timer_frequency() / 1000;
if (timer_frequency_in_khz == 0)
return 0;
grub_install_get_time_ms (generic_get_time_ms);
have_timer = 1;
return 1;
}
void
grub_machine_timer_init (void)
{
grub_fdtbus_register (&sp804);
if (!have_timer)
try_generic_timer ();
if (!have_timer)
grub_fatal ("No timer found");
}
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