xref: /openbmc/linux/arch/arm/mach-tegra/reset-handler.S (revision 840ef8b7cc584a23c4f9d05352f4dbaf8e56e5ab)
1/*
2 * Copyright (c) 2012, NVIDIA Corporation. All rights reserved.
3 *
4 * This program is free software; you can redistribute it and/or modify it
5 * under the terms and conditions of the GNU General Public License,
6 * version 2, as published by the Free Software Foundation.
7 *
8 * This program is distributed in the hope it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
11 * more details.
12 *
13 * You should have received a copy of the GNU General Public License
14 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
15 */
16
17#include <linux/linkage.h>
18#include <linux/init.h>
19
20#include <asm/cache.h>
21#include <asm/asm-offsets.h>
22#include <asm/hardware/cache-l2x0.h>
23
24#include "flowctrl.h"
25#include "iomap.h"
26#include "reset.h"
27#include "sleep.h"
28
29#define APB_MISC_GP_HIDREV	0x804
30#define PMC_SCRATCH41	0x140
31
32#define RESET_DATA(x)	((TEGRA_RESET_##x)*4)
33
34#ifdef CONFIG_PM_SLEEP
35/*
36 *	tegra_resume
37 *
38 *	  CPU boot vector when restarting the a CPU following
39 *	  an LP2 transition. Also branched to by LP0 and LP1 resume after
40 *	  re-enabling sdram.
41 */
42ENTRY(tegra_resume)
43	bl	v7_invalidate_l1
44	/* Enable coresight */
45	mov32	r0, 0xC5ACCE55
46	mcr	p14, 0, r0, c7, c12, 6
47
48	cpu_id	r0
49	cmp	r0, #0				@ CPU0?
50	bne	cpu_resume			@ no
51
52#ifdef CONFIG_ARCH_TEGRA_3x_SOC
53	/* Are we on Tegra20? */
54	mov32	r6, TEGRA_APB_MISC_BASE
55	ldr	r0, [r6, #APB_MISC_GP_HIDREV]
56	and	r0, r0, #0xff00
57	cmp	r0, #(0x20 << 8)
58	beq	1f				@ Yes
59	/* Clear the flow controller flags for this CPU. */
60	mov32	r2, TEGRA_FLOW_CTRL_BASE + FLOW_CTRL_CPU0_CSR	@ CPU0 CSR
61	ldr	r1, [r2]
62	/* Clear event & intr flag */
63	orr	r1, r1, \
64		#FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG
65	movw	r0, #0x0FFD	@ enable, cluster_switch, immed, & bitmaps
66	bic	r1, r1, r0
67	str	r1, [r2]
681:
69#endif
70
71#ifdef CONFIG_HAVE_ARM_SCU
72	/* enable SCU */
73	mov32	r0, TEGRA_ARM_PERIF_BASE
74	ldr	r1, [r0]
75	orr	r1, r1, #1
76	str	r1, [r0]
77#endif
78
79	/* L2 cache resume & re-enable */
80	l2_cache_resume r0, r1, r2, l2x0_saved_regs_addr
81
82	b	cpu_resume
83ENDPROC(tegra_resume)
84#endif
85
86#ifdef CONFIG_CACHE_L2X0
87	.globl	l2x0_saved_regs_addr
88l2x0_saved_regs_addr:
89	.long	0
90#endif
91
92	.align L1_CACHE_SHIFT
93ENTRY(__tegra_cpu_reset_handler_start)
94
95/*
96 * __tegra_cpu_reset_handler:
97 *
98 * Common handler for all CPU reset events.
99 *
100 * Register usage within the reset handler:
101 *
102 *      R7  = CPU present (to the OS) mask
103 *      R8  = CPU in LP1 state mask
104 *      R9  = CPU in LP2 state mask
105 *      R10 = CPU number
106 *      R11 = CPU mask
107 *      R12 = pointer to reset handler data
108 *
109 * NOTE: This code is copied to IRAM. All code and data accesses
110 *       must be position-independent.
111 */
112
113	.align L1_CACHE_SHIFT
114ENTRY(__tegra_cpu_reset_handler)
115
116	cpsid	aif, 0x13			@ SVC mode, interrupts disabled
117	mrc	p15, 0, r10, c0, c0, 5		@ MPIDR
118	and	r10, r10, #0x3			@ R10 = CPU number
119	mov	r11, #1
120	mov	r11, r11, lsl r10  		@ R11 = CPU mask
121	adr	r12, __tegra_cpu_reset_handler_data
122
123#ifdef CONFIG_SMP
124	/* Does the OS know about this CPU? */
125	ldr	r7, [r12, #RESET_DATA(MASK_PRESENT)]
126	tst	r7, r11 			@ if !present
127	bleq	__die				@ CPU not present (to OS)
128#endif
129
130#ifdef CONFIG_ARCH_TEGRA_2x_SOC
131	/* Are we on Tegra20? */
132	mov32	r6, TEGRA_APB_MISC_BASE
133	ldr	r0, [r6, #APB_MISC_GP_HIDREV]
134	and	r0, r0, #0xff00
135	cmp	r0, #(0x20 << 8)
136	bne	1f
137	/* If not CPU0, don't let CPU0 reset CPU1 now that CPU1 is coming up. */
138	mov32	r6, TEGRA_PMC_BASE
139	mov	r0, #0
140	cmp	r10, #0
141	strne	r0, [r6, #PMC_SCRATCH41]
1421:
143#endif
144
145	/* Waking up from LP2? */
146	ldr	r9, [r12, #RESET_DATA(MASK_LP2)]
147	tst	r9, r11				@ if in_lp2
148	beq	__is_not_lp2
149	ldr	lr, [r12, #RESET_DATA(STARTUP_LP2)]
150	cmp	lr, #0
151	bleq	__die				@ no LP2 startup handler
152	bx	lr
153
154__is_not_lp2:
155
156#ifdef CONFIG_SMP
157	/*
158	 * Can only be secondary boot (initial or hotplug) but CPU 0
159	 * cannot be here.
160	 */
161	cmp	r10, #0
162	bleq	__die				@ CPU0 cannot be here
163	ldr	lr, [r12, #RESET_DATA(STARTUP_SECONDARY)]
164	cmp	lr, #0
165	bleq	__die				@ no secondary startup handler
166	bx	lr
167#endif
168
169/*
170 * We don't know why the CPU reset. Just kill it.
171 * The LR register will contain the address we died at + 4.
172 */
173
174__die:
175	sub	lr, lr, #4
176	mov32	r7, TEGRA_PMC_BASE
177	str	lr, [r7, #PMC_SCRATCH41]
178
179	mov32	r7, TEGRA_CLK_RESET_BASE
180
181	/* Are we on Tegra20? */
182	mov32	r6, TEGRA_APB_MISC_BASE
183	ldr	r0, [r6, #APB_MISC_GP_HIDREV]
184	and	r0, r0, #0xff00
185	cmp	r0, #(0x20 << 8)
186	bne	1f
187
188#ifdef CONFIG_ARCH_TEGRA_2x_SOC
189	mov32	r0, 0x1111
190	mov	r1, r0, lsl r10
191	str	r1, [r7, #0x340]		@ CLK_RST_CPU_CMPLX_SET
192#endif
1931:
194#ifdef CONFIG_ARCH_TEGRA_3x_SOC
195	mov32	r6, TEGRA_FLOW_CTRL_BASE
196
197	cmp	r10, #0
198	moveq	r1, #FLOW_CTRL_HALT_CPU0_EVENTS
199	moveq	r2, #FLOW_CTRL_CPU0_CSR
200	movne	r1, r10, lsl #3
201	addne	r2, r1, #(FLOW_CTRL_CPU1_CSR-8)
202	addne	r1, r1, #(FLOW_CTRL_HALT_CPU1_EVENTS-8)
203
204	/* Clear CPU "event" and "interrupt" flags and power gate
205	   it when halting but not before it is in the "WFI" state. */
206	ldr	r0, [r6, +r2]
207	orr	r0, r0, #FLOW_CTRL_CSR_INTR_FLAG | FLOW_CTRL_CSR_EVENT_FLAG
208	orr	r0, r0, #FLOW_CTRL_CSR_ENABLE
209	str	r0, [r6, +r2]
210
211	/* Unconditionally halt this CPU */
212	mov	r0, #FLOW_CTRL_WAITEVENT
213	str	r0, [r6, +r1]
214	ldr	r0, [r6, +r1]			@ memory barrier
215
216	dsb
217	isb
218	wfi					@ CPU should be power gated here
219
220	/* If the CPU didn't power gate above just kill it's clock. */
221
222	mov	r0, r11, lsl #8
223	str	r0, [r7, #348]			@ CLK_CPU_CMPLX_SET
224#endif
225
226	/* If the CPU still isn't dead, just spin here. */
227	b	.
228ENDPROC(__tegra_cpu_reset_handler)
229
230	.align L1_CACHE_SHIFT
231	.type	__tegra_cpu_reset_handler_data, %object
232	.globl	__tegra_cpu_reset_handler_data
233__tegra_cpu_reset_handler_data:
234	.rept	TEGRA_RESET_DATA_SIZE
235	.long	0
236	.endr
237	.align L1_CACHE_SHIFT
238
239ENTRY(__tegra_cpu_reset_handler_end)
240