ARM: sunxi: Add sun6i specific PSCI implementation

This adds PSCI support for sun6i. So far it only supports
the PWR_ON method.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>

arch/arm/cpu/armv7/sunxi/Makefile

@@ -35,6 +35,7 @@ obj-$(CONFIG_AXP221_POWER)	+= pmic_bus.o
 
 ifndef CONFIG_SPL_BUILD
 ifdef CONFIG_ARMV7_PSCI
+obj-$(CONFIG_MACH_SUN6I)	+= psci_sun6i.o
 obj-$(CONFIG_MACH_SUN7I)	+= psci_sun7i.o
 endif
 endif

arch/arm/cpu/armv7/sunxi/psci_sun6i.S

@@ -0,0 +1,276 @@
+/*
+ * Copyright (C) 2015 - Chen-Yu Tsai
+ * Author: Chen-Yu Tsai <wens@csie.org>
+ *
+ * Based on psci_sun7i.S by Marc Zyngier <marc.zyngier@arm.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope that 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 <config.h>
+#include <asm/gic.h>
+#include <asm/macro.h>
+#include <asm/psci.h>
+#include <asm/arch/cpu.h>
+
+/*
+ * Memory layout:
+ *
+ * SECURE_RAM to text_end :
+ *	._secure_text section
+ * text_end to ALIGN_PAGE(text_end):
+ *	nothing
+ * ALIGN_PAGE(text_end) to ALIGN_PAGE(text_end) + 0x1000)
+ *	1kB of stack per CPU (4 CPUs max).
+ */
+
+	.pushsection ._secure.text, "ax"
+
+	.arch_extension sec
+
+#define	ONE_MS			(CONFIG_TIMER_CLK_FREQ / 1000)
+#define	TEN_MS			(10 * ONE_MS)
+#define	GICD_BASE		0x1c81000
+#define	GICC_BASE		0x1c82000
+
+.macro	timer_wait	reg, ticks
+	@ Program CNTP_TVAL
+	movw	\reg, #(\ticks & 0xffff)
+	movt	\reg, #(\ticks >> 16)
+	mcr	p15, 0, \reg, c14, c2, 0
+	isb
+	@ Enable physical timer, mask interrupt
+	mov	\reg, #3
+	mcr	p15, 0, \reg, c14, c2, 1
+	@ Poll physical timer until ISTATUS is on
+1:	isb
+	mrc	p15, 0, \reg, c14, c2, 1
+	ands	\reg, \reg, #4
+	bne	1b
+	@ Disable timer
+	mov	\reg, #0
+	mcr	p15, 0, \reg, c14, c2, 1
+	isb
+.endm
+
+.globl	psci_fiq_enter
+psci_fiq_enter:
+	push	{r0-r12}
+
+	@ Switch to secure
+	mrc	p15, 0, r7, c1, c1, 0
+	bic	r8, r7, #1
+	mcr	p15, 0, r8, c1, c1, 0
+	isb
+
+	@ Validate reason based on IAR and acknowledge
+	movw	r8, #(GICC_BASE & 0xffff)
+	movt	r8, #(GICC_BASE >> 16)
+	ldr	r9, [r8, #GICC_IAR]
+	movw	r10, #0x3ff
+	movt	r10, #0
+	cmp	r9, r10			@ skip spurious interrupt 1023
+	beq	out
+	movw	r10, #0x3fe		@ ...and 1022
+	cmp	r9, r10
+	beq	out
+	str	r9, [r8, #GICC_EOIR]	@ acknowledge the interrupt
+	dsb
+
+	@ Compute CPU number
+	lsr	r9, r9, #10
+	and	r9, r9, #0xf
+
+	movw	r8, #(SUN6I_CPUCFG_BASE & 0xffff)
+	movt	r8, #(SUN6I_CPUCFG_BASE >> 16)
+
+	@ Wait for the core to enter WFI
+	lsl	r11, r9, #6		@ x64
+	add	r11, r11, r8
+
+1:	ldr	r10, [r11, #0x48]
+	tst	r10, #(1 << 2)
+	bne	2f
+	timer_wait r10, ONE_MS
+	b	1b
+
+	@ Reset CPU
+2:	mov	r10, #0
+	str	r10, [r11, #0x40]
+
+	@ Lock CPU
+	mov	r10, #1
+	lsl	r11, r10, r9		@ r11 is now CPU mask
+	ldr	r10, [r8, #0x1e4]
+	bic	r10, r10, r11
+	str	r10, [r8, #0x1e4]
+
+	movw	r8, #(SUNXI_PRCM_BASE & 0xffff)
+	movt	r8, #(SUNXI_PRCM_BASE >> 16)
+
+	@ Set power gating
+	ldr	r10, [r8, #0x100]
+	orr	r10, r10, r11
+	str	r10, [r8, #0x100]
+	timer_wait r10, ONE_MS
+
+	@ Activate power clamp
+	lsl	r12, r9, #2		@ x4
+	add	r12, r12, r8
+	mov	r10, #0xff
+	str	r10, [r12, #0x140]
+
+	movw	r8, #(SUN6I_CPUCFG_BASE & 0xffff)
+	movt	r8, #(SUN6I_CPUCFG_BASE >> 16)
+
+	@ Unlock CPU
+	ldr	r10, [r8, #0x1e4]
+	orr	r10, r10, r11
+	str	r10, [r8, #0x1e4]
+
+	@ Restore security level
+out:	mcr	p15, 0, r7, c1, c1, 0
+
+	pop	{r0-r12}
+	subs    pc, lr, #4
+
+	@ r1 = target CPU
+	@ r2 = target PC
+.globl	psci_cpu_on
+psci_cpu_on:
+	push	{lr}
+
+	mov	r0, r1
+	bl	psci_get_cpu_stack_top	@ get stack top of target CPU
+	str	r2, [r0]		@ store target PC at stack top
+	dsb
+
+	movw	r0, #(SUN6I_CPUCFG_BASE & 0xffff)
+	movt	r0, #(SUN6I_CPUCFG_BASE >> 16)
+
+	@ CPU mask
+	and	r1, r1, #3	@ only care about first cluster
+	mov	r4, #1
+	lsl	r4, r4, r1
+
+	ldr	r6, =psci_cpu_entry
+	str	r6, [r0, #0x1a4] @ PRIVATE_REG (boot vector)
+
+	@ Assert reset on target CPU
+	mov	r6, #0
+	lsl	r5, r1, #6	@ 64 bytes per CPU
+	add	r5, r5, #0x40	@ Offset from base
+	add	r5, r5, r0	@ CPU control block
+	str	r6, [r5]	@ Reset CPU
+
+	@ l1 invalidate
+	ldr	r6, [r0, #0x184] @ CPUCFG_GEN_CTRL_REG
+	bic	r6, r6, r4
+	str	r6, [r0, #0x184]
+
+	@ Lock CPU (Disable external debug access)
+	ldr	r6, [r0, #0x1e4] @ CPUCFG_DBG_CTL1_REG
+	bic	r6, r6, r4
+	str	r6, [r0, #0x1e4]
+
+	movw	r0, #(SUNXI_PRCM_BASE & 0xffff)
+	movt	r0, #(SUNXI_PRCM_BASE >> 16)
+
+	@ Release power clamp
+	lsl	r5, r1, #2	@ 1 register per CPU
+	add	r5, r5, r0	@ PRCM
+	movw	r6, #0x1ff
+	movt	r6, #0
+1:	lsrs	r6, r6, #1
+	str	r6, [r5, #0x140] @ CPUx_PWR_CLAMP
+	bne	1b
+
+	timer_wait r6, TEN_MS
+
+	@ Clear power gating
+	ldr	r6, [r0, #0x100] @ CPU_PWROFF_GATING
+	bic	r6, r6, r4
+	str	r6, [r0, #0x100]
+
+	@ re-calculate CPU control register address
+	movw	r0, #(SUN6I_CPUCFG_BASE & 0xffff)
+	movt	r0, #(SUN6I_CPUCFG_BASE >> 16)
+
+	@ Deassert reset on target CPU
+	mov	r6, #3
+	lsl	r5, r1, #6	@ 64 bytes per CPU
+	add	r5, r5, #0x40	@ Offset from base
+	add	r5, r5, r0	@ CPU control block
+	str	r6, [r5]
+
+	@ Unlock CPU (Enable external debug access)
+	ldr	r6, [r0, #0x1e4] @ CPUCFG_DBG_CTL1_REG
+	orr	r6, r6, r4
+	str	r6, [r0, #0x1e4]
+
+	mov	r0, #ARM_PSCI_RET_SUCCESS	@ Return PSCI_RET_SUCCESS
+	pop	{pc}
+
+.globl	psci_cpu_off
+psci_cpu_off:
+	bl	psci_cpu_off_common
+
+	@ Ask CPU0 to pull the rug...
+	movw	r0, #(GICD_BASE & 0xffff)
+	movt	r0, #(GICD_BASE >> 16)
+	movw	r1, #15				@ SGI15
+	movt	r1, #1				@ Target is CPU0
+	str	r1, [r0, #GICD_SGIR]
+	dsb
+
+1:	wfi
+	b	1b
+
+.globl	psci_arch_init
+psci_arch_init:
+	mov	r6, lr
+
+	movw	r4, #(GICD_BASE & 0xffff)
+	movt	r4, #(GICD_BASE >> 16)
+
+	ldr	r5, [r4, #GICD_IGROUPRn]
+	bic	r5, r5, #(1 << 15) 	@ SGI15 as Group-0
+	str	r5, [r4, #GICD_IGROUPRn]
+
+	mov	r5, #0			@ Set SGI15 priority to 0
+	strb	r5, [r4, #(GICD_IPRIORITYRn + 15)]
+
+	add	r4, r4, #0x1000		@ GICC address
+
+	mov	r5, #0xff
+	str	r5, [r4, #GICC_PMR]	@ Be cool with non-secure
+
+	ldr	r5, [r4, #GICC_CTLR]
+	orr	r5, r5, #(1 << 3)	@ Switch FIQEn on
+	str	r5, [r4, #GICC_CTLR]
+
+	mrc	p15, 0, r5, c1, c1, 0	@ Read SCR
+	orr	r5, r5, #4		@ Enable FIQ in monitor mode
+	bic	r5, r5, #1		@ Secure mode
+	mcr	p15, 0, r5, c1, c1, 0	@ Write SCR
+	isb
+
+	bl	psci_get_cpu_id		@ CPU ID => r0
+	bl	psci_get_cpu_stack_top	@ stack top => r0
+	mov	sp, r0
+
+	bx	r6
+
+	.globl psci_text_end
+psci_text_end:
+	.popsection