xref: /openbmc/linux/arch/arm/include/debug/brcmstb.S (revision 15d5761a)
1/*
2 * Copyright (C) 2016 Broadcom
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License as
6 * published by the Free Software Foundation version 2.
7 *
8 * This program is distributed "as is" WITHOUT ANY WARRANTY of any
9 * kind, whether express or implied; without even the implied warranty
10 * of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
11 * GNU General Public License for more details.
12 */
13#include <linux/serial_reg.h>
14#include <asm/cputype.h>
15
16/* Physical register offset and virtual register offset */
17#define REG_PHYS_BASE		0xf0000000
18#define REG_PHYS_BASE_V7	0x08000000
19#define REG_VIRT_BASE		0xfc000000
20#define REG_PHYS_ADDR(x)	((x) + REG_PHYS_BASE)
21#define REG_PHYS_ADDR_V7(x)	((x) + REG_PHYS_BASE_V7)
22
23/* Product id can be read from here */
24#define SUN_TOP_CTRL_BASE	REG_PHYS_ADDR(0x404000)
25#define SUN_TOP_CTRL_BASE_V7	REG_PHYS_ADDR_V7(0x404000)
26
27#define UARTA_3390		REG_PHYS_ADDR(0x40a900)
28#define UARTA_7250		REG_PHYS_ADDR(0x40b400)
29#define UARTA_7255		REG_PHYS_ADDR(0x40c000)
30#define UARTA_7260		UARTA_7255
31#define UARTA_7268		UARTA_7255
32#define UARTA_7271		UARTA_7268
33#define UARTA_7278		REG_PHYS_ADDR_V7(0x40c000)
34#define UARTA_7216		UARTA_7278
35#define UARTA_7364		REG_PHYS_ADDR(0x40b000)
36#define UARTA_7366		UARTA_7364
37#define UARTA_74371		REG_PHYS_ADDR(0x406b00)
38#define UARTA_7439		REG_PHYS_ADDR(0x40a900)
39#define UARTA_7445		REG_PHYS_ADDR(0x40ab00)
40
41#define UART_SHIFT		2
42
43#define checkuart(rp, rv, family_id, family) \
44		/* Load family id */ \
45		ldr	rp, =family_id ; \
46		/* Compare SUN_TOP_CTRL value against it */ \
47		cmp	rp, rv ; \
48		/* Passed test, load address */ \
49		ldreq	rp, =UARTA_##family ; \
50		/* Jump to save UART address */ \
51		beq	91f
52
53		.macro  addruart, rp, rv, tmp
54		adr	\rp, 99f		@ actual addr of 99f
55		ldr	\rv, [\rp]		@ linked addr is stored there
56		sub	\rv, \rv, \rp		@ offset between the two
57		ldr	\rp, [\rp, #4]		@ linked brcmstb_uart_config
58		sub	\tmp, \rp, \rv		@ actual brcmstb_uart_config
59		ldr	\rp, [\tmp]		@ Load brcmstb_uart_config
60		cmp	\rp, #1			@ needs initialization?
61		bne	100f			@ no; go load the addresses
62		mov	\rv, #0			@ yes; record init is done
63		str	\rv, [\tmp]
64
65		/* Check for V7 memory map if B53 */
66		mrc	p15, 0, \rv, c0, c0, 0	@ get Main ID register
67		ldr	\rp, =ARM_CPU_PART_MASK
68		and	\rv, \rv, \rp
69		ldr	\rp, =ARM_CPU_PART_BRAHMA_B53	@ check for B53 CPU
70		cmp	\rv, \rp
71		bne	10f
72
73		/* if PERIPHBASE doesn't overlap REG_PHYS_BASE use V7 map */
74		mrc	p15, 1, \rv, c15, c3, 0	@ get PERIPHBASE from CBAR
75		ands	\rv, \rv, #REG_PHYS_BASE
76		ldreq	\rp, =SUN_TOP_CTRL_BASE_V7
77
78		/* Check SUN_TOP_CTRL base */
7910:		ldrne	\rp, =SUN_TOP_CTRL_BASE	@ load SUN_TOP_CTRL PA
80		ldr	\rv, [\rp, #0]		@ get register contents
81ARM_BE8(	rev	\rv, \rv )
82		and	\rv, \rv, #0xffffff00	@ strip revision bits [7:0]
83
84		/* Chip specific detection starts here */
8520:		checkuart(\rp, \rv, 0x33900000, 3390)
8621:		checkuart(\rp, \rv, 0x72160000, 7216)
8722:		checkuart(\rp, \rv, 0x72500000, 7250)
8823:		checkuart(\rp, \rv, 0x72550000, 7255)
8924:		checkuart(\rp, \rv, 0x72600000, 7260)
9025:		checkuart(\rp, \rv, 0x72680000, 7268)
9126:		checkuart(\rp, \rv, 0x72710000, 7271)
9227:		checkuart(\rp, \rv, 0x72780000, 7278)
9328:		checkuart(\rp, \rv, 0x73640000, 7364)
9429:		checkuart(\rp, \rv, 0x73660000, 7366)
9530:		checkuart(\rp, \rv, 0x07437100, 74371)
9631:		checkuart(\rp, \rv, 0x74390000, 7439)
9732:		checkuart(\rp, \rv, 0x74450000, 7445)
98
99		/* No valid UART found */
10090:		mov	\rp, #0
101		/* fall through */
102
103		/* Record whichever UART we chose */
10491:		str	\rp, [\tmp, #4]		@ Store in brcmstb_uart_phys
105		cmp	\rp, #0			@ Valid UART address?
106		bne	92f			@ Yes, go process it
107		str	\rp, [\tmp, #8]		@ Store 0 in brcmstb_uart_virt
108		b	100f			@ Done
10992:		and     \rv, \rp, #0xffffff	@ offset within 16MB section
110		add	\rv, \rv, #REG_VIRT_BASE
111		str	\rv, [\tmp, #8]		@ Store in brcmstb_uart_virt
112		b	100f
113
114		.align
11599:		.word	.
116		.word	brcmstb_uart_config
117		.ltorg
118
119		/* Load previously selected UART address */
120100:		ldr	\rp, [\tmp, #4]		@ Load brcmstb_uart_phys
121		ldr	\rv, [\tmp, #8]		@ Load brcmstb_uart_virt
122		.endm
123
124		.macro	store, rd, rx:vararg
125ARM_BE8(	rev	\rd, \rd )
126		str	\rd, \rx
127		.endm
128
129		.macro	load, rd, rx:vararg
130		ldr	\rd, \rx
131ARM_BE8(	rev	\rd, \rd )
132		.endm
133
134		.macro	senduart,rd,rx
135		store	\rd, [\rx, #UART_TX << UART_SHIFT]
136		.endm
137
138		.macro	busyuart,rd,rx
1391002:		load	\rd, [\rx, #UART_LSR << UART_SHIFT]
140		and	\rd, \rd, #UART_LSR_TEMT | UART_LSR_THRE
141		teq	\rd, #UART_LSR_TEMT | UART_LSR_THRE
142		bne	1002b
143		.endm
144
145		.macro	waituart,rd,rx
146		.endm
147
148/*
149 * Storage for the state maintained by the macros above.
150 *
151 * In the kernel proper, this data is located in arch/arm/mach-bcm/brcmstb.c.
152 * That's because this header is included from multiple files, and we only
153 * want a single copy of the data. In particular, the UART probing code above
154 * assumes it's running using physical addresses. This is true when this file
155 * is included from head.o, but not when included from debug.o. So we need
156 * to share the probe results between the two copies, rather than having
157 * to re-run the probing again later.
158 *
159 * In the decompressor, we put the symbol/storage right here, since common.c
160 * isn't included in the decompressor build. This symbol gets put in .text
161 * even though it's really data, since .data is discarded from the
162 * decompressor. Luckily, .text is writeable in the decompressor, unless
163 * CONFIG_ZBOOT_ROM. That dependency is handled in arch/arm/Kconfig.debug.
164 */
165#if defined(ZIMAGE)
166brcmstb_uart_config:
167	/* Debug UART initialization required */
168	.word 1
169	/* Debug UART physical address */
170	.word 0
171	/* Debug UART virtual address */
172	.word 0
173#endif
174