xref: /linux/arch/arm/include/debug/brcmstb.S (revision 0d3b051adbb72ed81956447d0d1e54d5943ee6f5)
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_72164		UARTA_7278
36#define UARTA_72165		UARTA_7278
37#define UARTA_7364		REG_PHYS_ADDR(0x40b000)
38#define UARTA_7366		UARTA_7364
39#define UARTA_74371		REG_PHYS_ADDR(0x406b00)
40#define UARTA_7439		REG_PHYS_ADDR(0x40a900)
41#define UARTA_7445		REG_PHYS_ADDR(0x40ab00)
42
43#define UART_SHIFT		2
44
45#define checkuart(rp, rv, family_id, family) \
46		/* Load family id */ \
47		ldr	rp, =family_id ; \
48		/* Compare SUN_TOP_CTRL value against it */ \
49		cmp	rp, rv ; \
50		/* Passed test, load address */ \
51		ldreq	rp, =UARTA_##family ; \
52		/* Jump to save UART address */ \
53		beq	91f
54
55		.macro  addruart, rp, rv, tmp
56		adr	\rp, 99f		@ actual addr of 99f
57		ldr	\rv, [\rp]		@ linked addr is stored there
58		sub	\rv, \rv, \rp		@ offset between the two
59		ldr	\rp, [\rp, #4]		@ linked brcmstb_uart_config
60		sub	\tmp, \rp, \rv		@ actual brcmstb_uart_config
61		ldr	\rp, [\tmp]		@ Load brcmstb_uart_config
62		cmp	\rp, #1			@ needs initialization?
63		bne	100f			@ no; go load the addresses
64		mov	\rv, #0			@ yes; record init is done
65		str	\rv, [\tmp]
66
67		/* Check for V7 memory map if B53 */
68		mrc	p15, 0, \rv, c0, c0, 0	@ get Main ID register
69		ldr	\rp, =ARM_CPU_PART_MASK
70		and	\rv, \rv, \rp
71		ldr	\rp, =ARM_CPU_PART_BRAHMA_B53	@ check for B53 CPU
72		cmp	\rv, \rp
73		bne	10f
74
75		/* if PERIPHBASE doesn't overlap REG_PHYS_BASE use V7 map */
76		mrc	p15, 1, \rv, c15, c3, 0	@ get PERIPHBASE from CBAR
77		ands	\rv, \rv, #REG_PHYS_BASE
78		ldreq	\rp, =SUN_TOP_CTRL_BASE_V7
79
80		/* Check SUN_TOP_CTRL base */
8110:		ldrne	\rp, =SUN_TOP_CTRL_BASE	@ load SUN_TOP_CTRL PA
82		ldr	\rv, [\rp, #0]		@ get register contents
83ARM_BE8(	rev	\rv, \rv )
84		and	\rv, \rv, #0xffffff00	@ strip revision bits [7:0]
85
86		/* Chip specific detection starts here */
8720:		checkuart(\rp, \rv, 0x33900000, 3390)
8821:		checkuart(\rp, \rv, 0x72160000, 7216)
8922:		checkuart(\rp, \rv, 0x07216400, 72164)
9023:		checkuart(\rp, \rv, 0x07216500, 72165)
9124:		checkuart(\rp, \rv, 0x72500000, 7250)
9225:		checkuart(\rp, \rv, 0x72550000, 7255)
9326:		checkuart(\rp, \rv, 0x72600000, 7260)
9427:		checkuart(\rp, \rv, 0x72680000, 7268)
9528:		checkuart(\rp, \rv, 0x72710000, 7271)
9629:		checkuart(\rp, \rv, 0x72780000, 7278)
9730:		checkuart(\rp, \rv, 0x73640000, 7364)
9831:		checkuart(\rp, \rv, 0x73660000, 7366)
9932:		checkuart(\rp, \rv, 0x07437100, 74371)
10033:		checkuart(\rp, \rv, 0x74390000, 7439)
10134:		checkuart(\rp, \rv, 0x74450000, 7445)
102
103		/* No valid UART found */
10490:		mov	\rp, #0
105		/* fall through */
106
107		/* Record whichever UART we chose */
10891:		str	\rp, [\tmp, #4]		@ Store in brcmstb_uart_phys
109		cmp	\rp, #0			@ Valid UART address?
110		bne	92f			@ Yes, go process it
111		str	\rp, [\tmp, #8]		@ Store 0 in brcmstb_uart_virt
112		b	100f			@ Done
11392:		and     \rv, \rp, #0xffffff	@ offset within 16MB section
114		add	\rv, \rv, #REG_VIRT_BASE
115		str	\rv, [\tmp, #8]		@ Store in brcmstb_uart_virt
116		b	100f
117
118		.align
11999:		.word	.
120		.word	brcmstb_uart_config
121		.ltorg
122
123		/* Load previously selected UART address */
124100:		ldr	\rp, [\tmp, #4]		@ Load brcmstb_uart_phys
125		ldr	\rv, [\tmp, #8]		@ Load brcmstb_uart_virt
126		.endm
127
128		.macro	store, rd, rx:vararg
129ARM_BE8(	rev	\rd, \rd )
130		str	\rd, \rx
131		.endm
132
133		.macro	load, rd, rx:vararg
134		ldr	\rd, \rx
135ARM_BE8(	rev	\rd, \rd )
136		.endm
137
138		.macro	senduart,rd,rx
139		store	\rd, [\rx, #UART_TX << UART_SHIFT]
140		.endm
141
142		.macro	busyuart,rd,rx
1431002:		load	\rd, [\rx, #UART_LSR << UART_SHIFT]
144		and	\rd, \rd, #UART_LSR_TEMT | UART_LSR_THRE
145		teq	\rd, #UART_LSR_TEMT | UART_LSR_THRE
146		bne	1002b
147		.endm
148
149		.macro	waituarttxrdy,rd,rx
150		.endm
151
152		.macro	waituartcts,rd,rx
153		.endm
154
155/*
156 * Storage for the state maintained by the macros above.
157 *
158 * In the kernel proper, this data is located in arch/arm/mach-bcm/brcmstb.c.
159 * That's because this header is included from multiple files, and we only
160 * want a single copy of the data. In particular, the UART probing code above
161 * assumes it's running using physical addresses. This is true when this file
162 * is included from head.o, but not when included from debug.o. So we need
163 * to share the probe results between the two copies, rather than having
164 * to re-run the probing again later.
165 *
166 * In the decompressor, we put the symbol/storage right here, since common.c
167 * isn't included in the decompressor build. This symbol gets put in .text
168 * even though it's really data, since .data is discarded from the
169 * decompressor. Luckily, .text is writeable in the decompressor, unless
170 * CONFIG_ZBOOT_ROM. That dependency is handled in arch/arm/Kconfig.debug.
171 */
172#if defined(ZIMAGE)
173brcmstb_uart_config:
174	/* Debug UART initialization required */
175	.word 1
176	/* Debug UART physical address */
177	.word 0
178	/* Debug UART virtual address */
179	.word 0
180#endif
181