path: root/arch/arm/mach-tegra/sleep-tegra20.S

/* SPDX-License-Identifier: GPL-2.0-only */
/*
 * Copyright (c) 2010-2012, NVIDIA Corporation. All rights reserved.
 * Copyright (c) 2011, Google, Inc.
 *
 * Author: Colin Cross <ccross@android.com>
 *         Gary King <gking@nvidia.com>
 */

#include <linux/linkage.h>

#include <soc/tegra/flowctrl.h>

#include <asm/assembler.h>
#include <asm/proc-fns.h>
#include <asm/cp15.h>
#include <asm/cache.h>

#include "irammap.h"
#include "reset.h"
#include "sleep.h"

#define EMC_CFG				0xc
#define EMC_ADR_CFG			0x10
#define EMC_NOP				0xdc
#define EMC_SELF_REF			0xe0
#define EMC_REQ_CTRL			0x2b0
#define EMC_EMC_STATUS			0x2b4

#define CLK_RESET_CCLK_BURST		0x20
#define CLK_RESET_CCLK_DIVIDER		0x24
#define CLK_RESET_SCLK_BURST		0x28
#define CLK_RESET_SCLK_DIVIDER		0x2c
#define CLK_RESET_PLLC_BASE		0x80
#define CLK_RESET_PLLM_BASE		0x90
#define CLK_RESET_PLLP_BASE		0xa0

#define APB_MISC_XM2CFGCPADCTRL		0x8c8
#define APB_MISC_XM2CFGDPADCTRL		0x8cc
#define APB_MISC_XM2CLKCFGPADCTRL	0x8d0
#define APB_MISC_XM2COMPPADCTRL		0x8d4
#define APB_MISC_XM2VTTGENPADCTRL	0x8d8
#define APB_MISC_XM2CFGCPADCTRL2	0x8e4
#define APB_MISC_XM2CFGDPADCTRL2	0x8e8

#define __tegra20_cpu1_resettable_status_offset \
	(__tegra_cpu_reset_handler_data_offset + RESET_DATA(RESETTABLE_STATUS))

.macro pll_enable, rd, r_car_base, pll_base
	ldr	\rd, [\r_car_base, #\pll_base]
	tst	\rd, #(1 << 30)
	orreq	\rd, \rd, #(1 << 30)
	streq	\rd, [\r_car_base, #\pll_base]
.endm

.macro emc_device_mask, rd, base
	ldr	\rd, [\base, #EMC_ADR_CFG]
	tst	\rd, #(0x3 << 24)
	moveq	\rd, #(0x1 << 8)		@ just 1 device
	movne	\rd, #(0x3 << 8)		@ 2 devices
.endm

#if defined(CONFIG_HOTPLUG_CPU) || defined(CONFIG_PM_SLEEP)
/*
 * tegra20_hotplug_shutdown(void)
 *
 * puts the current cpu in reset
 * should never return
 */
ENTRY(tegra20_hotplug_shutdown)
	/* Put this CPU down */
	cpu_id	r0
	bl	tegra20_cpu_shutdown
	ret	lr			@ should never get here
ENDPROC(tegra20_hotplug_shutdown)

/*
 * tegra20_cpu_shutdown(int cpu)
 *
 * r0 is cpu to reset
 *
 * puts the specified CPU in wait-for-event mode on the flow controller
 * and puts the CPU in reset
 * can be called on the current cpu or another cpu
 * if called on the current cpu, does not return
 * MUST NOT BE CALLED FOR CPU 0.
 *
 * corrupts r0-r3, r12
 */
ENTRY(tegra20_cpu_shutdown)
	cmp	r0, #0
	reteq	lr			@ must not be called for CPU 0
	mov32	r1, TEGRA_IRAM_RESET_BASE_VIRT
	ldr	r2, =__tegra20_cpu1_resettable_status_offset
	mov	r12, #CPU_RESETTABLE
	strb	r12, [r1, r2]

	cpu_to_halt_reg r1, r0
	ldr	r3, =TEGRA_FLOW_CTRL_VIRT
	mov	r2, #FLOW_CTRL_WAITEVENT | FLOW_CTRL_JTAG_RESUME
	str	r2, [r3, r1]		@ put flow controller in wait event mode
	ldr	r2, [r3, r1]
	isb
	dsb
	movw	r1, 0x1011
	mov	r1, r1, lsl r0
	ldr	r3, =TEGRA_CLK_RESET_VIRT
	str	r1, [r3, #0x340]	@ put slave CPU in reset
	isb
	dsb
	cpu_id	r3
	cmp	r3, r0
	beq	.
	ret	lr
ENDPROC(tegra20_cpu_shutdown)
#endif

#ifdef CONFIG_PM_SLEEP
/*
 * tegra_pen_lock
 *
 * spinlock implementation with no atomic test-and-set and no coherence
 * using Peterson's algorithm on strongly-ordered registers
 * used to synchronize a cpu waking up from wfi with entering lp2 on idle
 *
 * The reference link of Peterson's algorithm:
 * http://en.wikipedia.org/wiki/Peterson's_algorithm
 *
 * SCRATCH37 = r1 = !turn (inverted from Peterson's algorithm)
 * on cpu 0:
 * r2 = flag[0] (in SCRATCH38)
 * r3 = flag[1] (in SCRATCH39)
 * on cpu1:
 * r2 = flag[1] (in SCRATCH39)
 * r3 = flag[0] (in SCRATCH38)
 *
 * must be called with MMU on
 * corrupts r0-r3, r12
 */
ENTRY(tegra_pen_lock)
	mov32	r3, TEGRA_PMC_VIRT
	cpu_id	r0
	add	r1, r3, #PMC_SCRATCH37
	cmp	r0, #0
	addeq	r2, r3, #PMC_SCRATCH38
	addeq	r3, r3, #PMC_SCRATCH39
	addne	r2, r3, #PMC_SCRATCH39
	addne	r3, r3, #PMC_SCRATCH38

	mov	r12, #1
	str	r12, [r2]		@ flag[cpu] = 1
	dsb
	str	r12, [r1]		@ !turn = cpu
1:	dsb
	ldr	r12, [r3]
	cmp	r12, #1			@ flag[!cpu] == 1?
	ldreq	r12, [r1]
	cmpeq	r12, r0			@ !turn == cpu?
	beq	1b			@ while !turn == cpu && flag[!cpu] == 1

	ret	lr			@ locked
ENDPROC(tegra_pen_lock)

ENTRY(tegra_pen_unlock)
	dsb
	mov32	r3, TEGRA_PMC_VIRT
	cpu_id	r0
	cmp	r0, #0
	addeq	r2, r3, #PMC_SCRATCH38
	addne	r2, r3, #PMC_SCRATCH39
	mov	r12, #0
	str	r12, [r2]
	ret     lr
ENDPROC(tegra_pen_unlock)

/*
 * tegra20_cpu_clear_resettable(void)
 *
 * Called to clear the "resettable soon" flag in IRAM variable when
 * it is expected that the secondary CPU will be idle soon.
 */
ENTRY(tegra20_cpu_clear_resettable)
	mov32	r1, TEGRA_IRAM_RESET_BASE_VIRT
	ldr	r2, =__tegra20_cpu1_resettable_status_offset
	mov	r12, #CPU_NOT_RESETTABLE
	strb	r12, [r1, r2]
	ret	lr
ENDPROC(tegra20_cpu_clear_resettable)

/*
 * tegra20_cpu_set_resettable_soon(void)
 *
 * Called to set the "resettable soon" flag in IRAM variable when
 * it is expected that the secondary CPU will be idle soon.
 */
ENTRY(tegra20_cpu_set_resettable_soon)
	mov32	r1, TEGRA_IRAM_RESET_BASE_VIRT
	ldr	r2, =__tegra20_cpu1_resettable_status_offset
	mov	r12, #CPU_RESETTABLE_SOON
	strb	r12, [r1, r2]
	ret	lr
ENDPROC(tegra20_cpu_set_resettable_soon)

/*
 * tegra20_cpu_is_resettable_soon(void)
 *
 * Returns true if the "resettable soon" flag in IRAM variable has been
 * set because it is expected that the secondary CPU will be idle soon.
 */
ENTRY(tegra20_cpu_is_resettable_soon)
	mov32	r1, TEGRA_IRAM_RESET_BASE_VIRT
	ldr	r2, =__tegra20_cpu1_resettable_status_offset
	ldrb	r12, [r1, r2]
	cmp	r12, #CPU_RESETTABLE_SOON
	moveq	r0, #1
	movne	r0, #0
	ret	lr
ENDPROC(tegra20_cpu_is_resettable_soon)

/*
 * tegra20_sleep_core_finish(unsigned long v2p)
 *
 * Enters suspend in LP0 or LP1 by turning off the mmu and jumping to
 * tegra20_tear_down_core in IRAM
 */
ENTRY(tegra20_sleep_core_finish)
	mov     r4, r0
	/* Flush, disable the L1 data cache and exit SMP */
	mov     r0, #TEGRA_FLUSH_CACHE_ALL
	bl	tegra_disable_clean_inv_dcache
	mov     r0, r4

	mov32	r3, tegra_shut_off_mmu
	add	r3, r3, r0

	mov32	r0, tegra20_tear_down_core
	mov32	r1, tegra20_iram_start
	sub	r0, r0, r1
	mov32	r1, TEGRA_IRAM_LPx_RESUME_AREA
	add	r0, r0, r1

	ret	r3
ENDPROC(tegra20_sleep_core_finish)

/*
 * tegra20_sleep_cpu_secondary_finish(unsigned long v2p)
 *
 * Enters WFI on secondary CPU by exiting coherency.
 */
ENTRY(tegra20_sleep_cpu_secondary_finish)
	stmfd	sp!, {r4-r11, lr}

	mrc	p15, 0, r11, c1, c0, 1  @ save actlr before exiting coherency

	/* Flush and disable the L1 data cache */
	mov	r0, #TEGRA_FLUSH_CACHE_LOUIS
	bl	tegra_disable_clean_inv_dcache

	mov32	r0, TEGRA_IRAM_RESET_BASE_VIRT
	ldr	r4, =__tegra20_cpu1_resettable_status_offset
	mov	r3, #CPU_RESETTABLE
	strb	r3, [r0, r4]

	bl	tegra_cpu_do_idle

	/*
	 * cpu may be reset while in wfi, which will return through
	 * tegra_resume to cpu_resume
	 * or interrupt may wake wfi, which will return here
	 * cpu state is unchanged - MMU is on, cache is on, coherency
	 * is off, and the data cache is off
	 *
	 * r11 contains the original actlr
	 */

	bl	tegra_pen_lock

	mov32	r0, TEGRA_IRAM_RESET_BASE_VIRT
	ldr	r4, =__tegra20_cpu1_resettable_status_offset
	mov	r3, #CPU_NOT_RESETTABLE
	strb	r3, [r0, r4]

	bl	tegra_pen_unlock

	/* Re-enable the data cache */
	mrc	p15, 0, r10, c1, c0, 0
	orr	r10, r10, #CR_C
	mcr	p15, 0, r10, c1, c0, 0
	isb

	mcr	p15, 0, r11, c1, c0, 1	@ reenable coherency

	/* Invalidate the TLBs & BTAC */
	mov	r1, #0
	mcr	p15, 0, r1, c8, c3, 0	@ invalidate shared TLBs
	mcr	p15