Atmosphere/exosphere/warmboot/source/warmboot_clkrst.cpp

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2020-06-11 08:30:30 +00:00
/*
* Copyright (c) Atmosphère-NX
2020-06-11 08:30:30 +00:00
*
* This program is free software; you can redistribute it and/or modify it
* under the terms and conditions of the GNU General Public License,
* version 2, as published by the Free Software Foundation.
*
* This program is distributed in the hope 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 this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include <exosphere.hpp>
#include "warmboot_clkrst.hpp"
namespace ams::warmboot {
namespace {
constexpr inline const uintptr_t CLKRST = secmon::MemoryRegionPhysicalDeviceClkRst.GetAddress();
constexpr inline const uintptr_t PMC = secmon::MemoryRegionPhysicalDevicePmc.GetAddress();
constexpr inline const uintptr_t TIMER = secmon::MemoryRegionPhysicalDeviceTimer.GetAddress();
}
void ConfigureOscillators() {
/* Enable the crystal oscillator, and copy the drive strength from pmc. */
const auto xofs = reg::GetValue(PMC + APBDEV_PMC_OSC_EDPD_OVER, PMC_REG_BITS_MASK(OSC_EDPD_OVER_XOFS));
reg::ReadWrite(CLKRST + CLK_RST_CONTROLLER_OSC_CTRL, CLK_RST_REG_BITS_ENUM (OSC_CTRL_XOE, ENABLE),
CLK_RST_REG_BITS_VALUE(OSC_CTRL_XOFS, xofs));
/* Configure CLK_M_DIVISOR to 2. */
reg::Write(CLKRST + CLK_RST_CONTROLLER_SPARE_REG0, CLK_RST_REG_BITS_ENUM(SPARE_REG0_CLK_M_DIVISOR, CLK_M_DIVISOR2));
reg::Read(CLKRST + CLK_RST_CONTROLLER_SPARE_REG0);
/* Restore TIMERUS config to 19.2 MHz. */
reg::Write(TIMER + TIMERUS_USEC_CFG, TIMER_REG_BITS_VALUE(USEC_CFG_USEC_DIVIDEND, 5 - 1),
TIMER_REG_BITS_VALUE(USEC_CFG_USEC_DIVISOR, 96 - 1));
}
}