u-boot/arch/arm/cpu/armv7/sunxi/psci.c

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/*
* Copyright (C) 2016
* Author: Chen-Yu Tsai <wens@csie.org>
*
* Based on assembly code by Marc Zyngier <marc.zyngier@arm.com>,
* which was based on code by Carl van Schaik <carl@ok-labs.com>.
*
* SPDX-License-Identifier: GPL-2.0
*/
#include <config.h>
#include <common.h>
#include <asm/arch/cpu.h>
#include <asm/arch/cpucfg.h>
#include <asm/arch/prcm.h>
#include <asm/armv7.h>
#include <asm/gic.h>
#include <asm/io.h>
#include <asm/psci.h>
#include <asm/secure.h>
#include <asm/system.h>
#include <linux/bitops.h>
#define __irq __attribute__ ((interrupt ("IRQ")))
#define GICD_BASE (SUNXI_GIC400_BASE + GIC_DIST_OFFSET)
#define GICC_BASE (SUNXI_GIC400_BASE + GIC_CPU_OFFSET_A15)
static void __secure cp15_write_cntp_tval(u32 tval)
{
asm volatile ("mcr p15, 0, %0, c14, c2, 0" : : "r" (tval));
}
static void __secure cp15_write_cntp_ctl(u32 val)
{
asm volatile ("mcr p15, 0, %0, c14, c2, 1" : : "r" (val));
}
static u32 __secure cp15_read_cntp_ctl(void)
{
u32 val;
asm volatile ("mrc p15, 0, %0, c14, c2, 1" : "=r" (val));
return val;
}
#define ONE_MS (CONFIG_TIMER_CLK_FREQ / 1000)
static void __secure __mdelay(u32 ms)
{
u32 reg = ONE_MS * ms;
cp15_write_cntp_tval(reg);
isb();
cp15_write_cntp_ctl(3);
do {
isb();
reg = cp15_read_cntp_ctl();
} while (!(reg & BIT(2)));
cp15_write_cntp_ctl(0);
isb();
}
static void __secure clamp_release(u32 __maybe_unused *clamp)
{
#if defined(CONFIG_MACH_SUN6I) || defined(CONFIG_MACH_SUN7I) || \
defined(CONFIG_MACH_SUN8I_H3)
u32 tmp = 0x1ff;
do {
tmp >>= 1;
writel(tmp, clamp);
} while (tmp);
__mdelay(10);
#endif
}
static void __secure clamp_set(u32 __maybe_unused *clamp)
{
#if defined(CONFIG_MACH_SUN6I) || defined(CONFIG_MACH_SUN7I) || \
defined(CONFIG_MACH_SUN8I_H3)
writel(0xff, clamp);
#endif
}
static void __secure sunxi_power_switch(u32 *clamp, u32 *pwroff, bool on,
int cpu)
{
if (on) {
/* Release power clamp */
clamp_release(clamp);
/* Clear power gating */
clrbits_le32(pwroff, BIT(cpu));
} else {
/* Set power gating */
setbits_le32(pwroff, BIT(cpu));
/* Activate power clamp */
clamp_set(clamp);
}
}
#ifdef CONFIG_MACH_SUN7I
/* sun7i (A20) is different from other single cluster SoCs */
static void __secure sunxi_cpu_set_power(int __always_unused cpu, bool on)
{
struct sunxi_cpucfg_reg *cpucfg =
(struct sunxi_cpucfg_reg *)SUNXI_CPUCFG_BASE;
sunxi_power_switch(&cpucfg->cpu1_pwr_clamp, &cpucfg->cpu1_pwroff,
on, 0);
}
#else /* ! CONFIG_MACH_SUN7I */
static void __secure sunxi_cpu_set_power(int cpu, bool on)
{
struct sunxi_prcm_reg *prcm =
(struct sunxi_prcm_reg *)SUNXI_PRCM_BASE;
sunxi_power_switch(&prcm->cpu_pwr_clamp[cpu], &prcm->cpu_pwroff,
on, cpu);
}
#endif /* CONFIG_MACH_SUN7I */
void __secure sunxi_cpu_power_off(u32 cpuid)
{
struct sunxi_cpucfg_reg *cpucfg =
(struct sunxi_cpucfg_reg *)SUNXI_CPUCFG_BASE;
u32 cpu = cpuid & 0x3;
/* Wait for the core to enter WFI */
while (1) {
if (readl(&cpucfg->cpu[cpu].status) & BIT(2))
break;
__mdelay(1);
}
/* Assert reset on target CPU */
writel(0, &cpucfg->cpu[cpu].rst);
/* Lock CPU (Disable external debug access) */
clrbits_le32(&cpucfg->dbg_ctrl1, BIT(cpu));
/* Power down CPU */
sunxi_cpu_set_power(cpuid, false);
/* Unlock CPU (Disable external debug access) */
setbits_le32(&cpucfg->dbg_ctrl1, BIT(cpu));
}
static u32 __secure cp15_read_scr(void)
{
u32 scr;
asm volatile ("mrc p15, 0, %0, c1, c1, 0" : "=r" (scr));
return scr;
}
static void __secure cp15_write_scr(u32 scr)
{
asm volatile ("mcr p15, 0, %0, c1, c1, 0" : : "r" (scr));
isb();
}
/*
* Although this is an FIQ handler, the FIQ is processed in monitor mode,
* which means there's no FIQ banked registers. This is the same as IRQ
* mode, so use the IRQ attribute to ask the compiler to handler entry
* and return.
*/
void __secure __irq psci_fiq_enter(void)
{
u32 scr, reg, cpu;
/* Switch to secure mode */
scr = cp15_read_scr();
cp15_write_scr(scr & ~BIT(0));
/* Validate reason based on IAR and acknowledge */
reg = readl(GICC_BASE + GICC_IAR);
/* Skip spurious interrupts 1022 and 1023 */
if (reg == 1023 || reg == 1022)
goto out;
/* End of interrupt */
writel(reg, GICC_BASE + GICC_EOIR);
dsb();
/* Get CPU number */
cpu = (reg >> 10) & 0x7;
/* Power off the CPU */
sunxi_cpu_power_off(cpu);
out:
/* Restore security level */
cp15_write_scr(scr);
}
int __secure psci_cpu_on(u32 __always_unused unused, u32 mpidr, u32 pc)
{
struct sunxi_cpucfg_reg *cpucfg =
(struct sunxi_cpucfg_reg *)SUNXI_CPUCFG_BASE;
u32 cpu = (mpidr & 0x3);
/* store target PC */
psci_save_target_pc(cpu, pc);
/* Set secondary core power on PC */
writel((u32)&psci_cpu_entry, &cpucfg->priv0);
/* Assert reset on target CPU */
writel(0, &cpucfg->cpu[cpu].rst);
/* Invalidate L1 cache */
clrbits_le32(&cpucfg->gen_ctrl, BIT(cpu));
/* Lock CPU (Disable external debug access) */
clrbits_le32(&cpucfg->dbg_ctrl1, BIT(cpu));
/* Power up target CPU */
sunxi_cpu_set_power(cpu, true);
/* De-assert reset on target CPU */
writel(BIT(1) | BIT(0), &cpucfg->cpu[cpu].rst);
/* Unlock CPU (Disable external debug access) */
setbits_le32(&cpucfg->dbg_ctrl1, BIT(cpu));
return ARM_PSCI_RET_SUCCESS;
}
void __secure psci_cpu_off(void)
{
psci_cpu_off_common();
/* Ask CPU0 via SGI15 to pull the rug... */
writel(BIT(16) | 15, GICD_BASE + GICD_SGIR);
dsb();
/* Wait to be turned off */
while (1)
wfi();
}
void __secure psci_arch_init(void)
{
u32 reg;
/* SGI15 as Group-0 */
clrbits_le32(GICD_BASE + GICD_IGROUPRn, BIT(15));
/* Set SGI15 priority to 0 */
writeb(0, GICD_BASE + GICD_IPRIORITYRn + 15);
/* Be cool with non-secure */
writel(0xff, GICC_BASE + GICC_PMR);
/* Switch FIQEn on */
setbits_le32(GICC_BASE + GICC_CTLR, BIT(3));
reg = cp15_read_scr();
reg |= BIT(2); /* Enable FIQ in monitor mode */
reg &= ~BIT(0); /* Secure mode */
cp15_write_scr(reg);
}