xref: /openbmc/linux/arch/arm/include/debug/brcmstb.S (revision b830f94f)
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_7364		REG_PHYS_ADDR(0x40b000)
35#define UARTA_7366		UARTA_7364
36#define UARTA_74371		REG_PHYS_ADDR(0x406b00)
37#define UARTA_7439		REG_PHYS_ADDR(0x40a900)
38#define UARTA_7445		REG_PHYS_ADDR(0x40ab00)
39
40#define UART_SHIFT		2
41
42#define checkuart(rp, rv, family_id, family) \
43		/* Load family id */ \
44		ldr	rp, =family_id ; \
45		/* Compare SUN_TOP_CTRL value against it */ \
46		cmp	rp, rv ; \
47		/* Passed test, load address */ \
48		ldreq	rp, =UARTA_##family ; \
49		/* Jump to save UART address */ \
50		beq	91f
51
52		.macro  addruart, rp, rv, tmp
53		adr	\rp, 99f		@ actual addr of 99f
54		ldr	\rv, [\rp]		@ linked addr is stored there
55		sub	\rv, \rv, \rp		@ offset between the two
56		ldr	\rp, [\rp, #4]		@ linked brcmstb_uart_config
57		sub	\tmp, \rp, \rv		@ actual brcmstb_uart_config
58		ldr	\rp, [\tmp]		@ Load brcmstb_uart_config
59		cmp	\rp, #1			@ needs initialization?
60		bne	100f			@ no; go load the addresses
61		mov	\rv, #0			@ yes; record init is done
62		str	\rv, [\tmp]
63
64		/* Check for V7 memory map if B53 */
65		mrc	p15, 0, \rv, c0, c0, 0	@ get Main ID register
66		ldr	\rp, =ARM_CPU_PART_MASK
67		and	\rv, \rv, \rp
68		ldr	\rp, =ARM_CPU_PART_BRAHMA_B53	@ check for B53 CPU
69		cmp	\rv, \rp
70		bne	10f
71
72		/* if PERIPHBASE doesn't overlap REG_PHYS_BASE use V7 map */
73		mrc	p15, 1, \rv, c15, c3, 0	@ get PERIPHBASE from CBAR
74		ands	\rv, \rv, #REG_PHYS_BASE
75		ldreq	\rp, =SUN_TOP_CTRL_BASE_V7
76
77		/* Check SUN_TOP_CTRL base */
7810:		ldrne	\rp, =SUN_TOP_CTRL_BASE	@ load SUN_TOP_CTRL PA
79		ldr	\rv, [\rp, #0]		@ get register contents
80ARM_BE8(	rev	\rv, \rv )
81		and	\rv, \rv, #0xffffff00	@ strip revision bits [7:0]
82
83		/* Chip specific detection starts here */
8420:		checkuart(\rp, \rv, 0x33900000, 3390)
8521:		checkuart(\rp, \rv, 0x72500000, 7250)
8622:		checkuart(\rp, \rv, 0x72550000, 7255)
8723:		checkuart(\rp, \rv, 0x72600000, 7260)
8824:		checkuart(\rp, \rv, 0x72680000, 7268)
8925:		checkuart(\rp, \rv, 0x72710000, 7271)
9026:		checkuart(\rp, \rv, 0x72780000, 7278)
9127:		checkuart(\rp, \rv, 0x73640000, 7364)
9228:		checkuart(\rp, \rv, 0x73660000, 7366)
9329:		checkuart(\rp, \rv, 0x07437100, 74371)
9430:		checkuart(\rp, \rv, 0x74390000, 7439)
9531:		checkuart(\rp, \rv, 0x74450000, 7445)
96
97		/* No valid UART found */
9890:		mov	\rp, #0
99		/* fall through */
100
101		/* Record whichever UART we chose */
10291:		str	\rp, [\tmp, #4]		@ Store in brcmstb_uart_phys
103		cmp	\rp, #0			@ Valid UART address?
104		bne	92f			@ Yes, go process it
105		str	\rp, [\tmp, #8]		@ Store 0 in brcmstb_uart_virt
106		b	100f			@ Done
10792:		and     \rv, \rp, #0xffffff	@ offset within 16MB section
108		add	\rv, \rv, #REG_VIRT_BASE
109		str	\rv, [\tmp, #8]		@ Store in brcmstb_uart_virt
110		b	100f
111
112		.align
11399:		.word	.
114		.word	brcmstb_uart_config
115		.ltorg
116
117		/* Load previously selected UART address */
118100:		ldr	\rp, [\tmp, #4]		@ Load brcmstb_uart_phys
119		ldr	\rv, [\tmp, #8]		@ Load brcmstb_uart_virt
120		.endm
121
122		.macro	store, rd, rx:vararg
123ARM_BE8(	rev	\rd, \rd )
124		str	\rd, \rx
125		.endm
126
127		.macro	load, rd, rx:vararg
128		ldr	\rd, \rx
129ARM_BE8(	rev	\rd, \rd )
130		.endm
131
132		.macro	senduart,rd,rx
133		store	\rd, [\rx, #UART_TX << UART_SHIFT]
134		.endm
135
136		.macro	busyuart,rd,rx
1371002:		load	\rd, [\rx, #UART_LSR << UART_SHIFT]
138		and	\rd, \rd, #UART_LSR_TEMT | UART_LSR_THRE
139		teq	\rd, #UART_LSR_TEMT | UART_LSR_THRE
140		bne	1002b
141		.endm
142
143		.macro	waituart,rd,rx
144		.endm
145
146/*
147 * Storage for the state maintained by the macros above.
148 *
149 * In the kernel proper, this data is located in arch/arm/mach-bcm/brcmstb.c.
150 * That's because this header is included from multiple files, and we only
151 * want a single copy of the data. In particular, the UART probing code above
152 * assumes it's running using physical addresses. This is true when this file
153 * is included from head.o, but not when included from debug.o. So we need
154 * to share the probe results between the two copies, rather than having
155 * to re-run the probing again later.
156 *
157 * In the decompressor, we put the symbol/storage right here, since common.c
158 * isn't included in the decompressor build. This symbol gets put in .text
159 * even though it's really data, since .data is discarded from the
160 * decompressor. Luckily, .text is writeable in the decompressor, unless
161 * CONFIG_ZBOOT_ROM. That dependency is handled in arch/arm/Kconfig.debug.
162 */
163#if defined(ZIMAGE)
164brcmstb_uart_config:
165	/* Debug UART initialization required */
166	.word 1
167	/* Debug UART physical address */
168	.word 0
169	/* Debug UART virtual address */
170	.word 0
171#endif
172