pmu.c
2.06 KB
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/*
* Copyright (c) 2017 Intel Corporation
*
* SPDX-License-Identifier: GPL-2.0+
*/
#include <common.h>
#include <dm.h>
#include <regmap.h>
#include <syscon.h>
#include <asm/cpu.h>
#include <asm/pmu.h>
#include <linux/errno.h>
#include <linux/io.h>
/* Registers */
struct pmu_regs {
u32 sts;
u32 cmd;
u32 ics;
u32 reserved;
u32 wkc[4];
u32 wks[4];
u32 ssc[4];
u32 sss[4];
};
/* Bits in PMU_REGS_STS */
#define PMU_REGS_STS_BUSY (1 << 8)
struct pmu_mid {
struct pmu_regs *regs;
};
static int pmu_read_status(struct pmu_regs *regs)
{
int retry = 500000;
u32 val;
do {
val = readl(®s->sts);
if (!(val & PMU_REGS_STS_BUSY))
return 0;
udelay(1);
} while (--retry);
printf("WARNING: PMU still busy\n");
return -EBUSY;
}
static int pmu_power_lss(struct pmu_regs *regs, unsigned int lss, bool on)
{
unsigned int offset = (lss * 2) / 32;
unsigned int shift = (lss * 2) % 32;
u32 ssc;
int ret;
/* Check PMU status */
ret = pmu_read_status(regs);
if (ret)
return ret;
/* Read PMU values */
ssc = readl(®s->sss[offset]);
/* Modify PMU values */
if (on)
ssc &= ~(0x3 << shift); /* D0 */
else
ssc |= 0x3 << shift; /* D3hot */
/* Write modified PMU values */
writel(ssc, ®s->ssc[offset]);
/* Update modified PMU values */
writel(0x00002201, ®s->cmd);
/* Check PMU status */
return pmu_read_status(regs);
}
int pmu_turn_power(unsigned int lss, bool on)
{
struct pmu_mid *pmu;
struct udevice *dev;
int ret;
ret = syscon_get_by_driver_data(X86_SYSCON_PMU, &dev);
if (ret)
return ret;
pmu = dev_get_priv(dev);
return pmu_power_lss(pmu->regs, lss, on);
}
static int pmu_mid_probe(struct udevice *dev)
{
struct pmu_mid *pmu = dev_get_priv(dev);
pmu->regs = syscon_get_first_range(X86_SYSCON_PMU);
return 0;
}
static const struct udevice_id pmu_mid_match[] = {
{ .compatible = "intel,pmu-mid", .data = X86_SYSCON_PMU },
{ /* sentinel */ }
};
U_BOOT_DRIVER(intel_mid_pmu) = {
.name = "pmu_mid",
.id = UCLASS_SYSCON,
.of_match = pmu_mid_match,
.probe = pmu_mid_probe,
.priv_auto_alloc_size = sizeof(struct pmu_mid),
};