u-boot/arch/x86/cpu/apollolake/punit.c

95 lines
2.1 KiB
C
Raw Normal View History

// SPDX-License-Identifier: GPL-2.0
/*
* Copyright 2019 Google LLC
*/
#include <common.h>
#include <dm.h>
#include <spl.h>
#include <asm/cpu.h>
#include <asm/cpu_common.h>
#include <asm/intel_regs.h>
#include <asm/io.h>
#include <asm/pci.h>
#include <asm/arch/systemagent.h>
/*
* Punit Initialisation code. This all isn't documented, but
* this is the recipe.
*/
static int punit_init(struct udevice *dev)
{
struct udevice *cpu;
u32 reg;
ulong start;
int ret;
/* Thermal throttle activation offset */
ret = uclass_first_device_err(UCLASS_CPU, &cpu);
if (ret)
return log_msg_ret("Cannot find CPU", ret);
cpu_configure_thermal_target(cpu);
/*
* Software Core Disable Mask (P_CR_CORE_DISABLE_MASK_0_0_0_MCHBAR).
* Enable all cores here.
*/
writel(0, MCHBAR_REG(CORE_DISABLE_MASK));
/* P-Unit bring up */
reg = readl(MCHBAR_REG(BIOS_RESET_CPL));
if (reg == 0xffffffff) {
/* P-unit not found */
debug("Punit MMIO not available\n");
return -ENOENT;
}
/* Set Punit interrupt pin IPIN offset 3D */
dm_pci_write_config8(dev, PCI_INTERRUPT_PIN, 0x2);
/* Set PUINT IRQ to 24 and INTPIN LOCK */
writel(PUINT_THERMAL_DEVICE_IRQ_VEC_NUMBER |
PUINT_THERMAL_DEVICE_IRQ_LOCK,
MCHBAR_REG(PUNIT_THERMAL_DEVICE_IRQ));
/* Stage0 BIOS Reset Complete (RST_CPL) */
enable_bios_reset_cpl();
/*
* Poll for bit 8 to check if PCODE has completed its action in response
* to BIOS Reset complete. We wait here till 1 ms for the bit to get
* set.
*/
start = get_timer(0);
while (!(readl(MCHBAR_REG(BIOS_RESET_CPL)) & PCODE_INIT_DONE)) {
if (get_timer(start) > 1) {
debug("PCODE Init Done timeout\n");
return -ETIMEDOUT;
}
udelay(100);
}
debug("PUNIT init complete\n");
return 0;
}
static int apl_punit_probe(struct udevice *dev)
{
if (spl_phase() == PHASE_SPL)
return punit_init(dev);
return 0;
}
static const struct udevice_id apl_syscon_ids[] = {
{ .compatible = "intel,apl-punit", .data = X86_SYSCON_PUNIT },
{ }
};
U_BOOT_DRIVER(syscon_intel_punit) = {
.name = "intel_punit_syscon",
.id = UCLASS_SYSCON,
.of_match = apl_syscon_ids,
.probe = apl_punit_probe,
};