xref: /openbmc/linux/arch/arm/include/debug/brcmstb.S (revision b9b77222)
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_7260		REG_PHYS_ADDR(0x40c000)
30#define UARTA_7268		UARTA_7260
31#define UARTA_7271		UARTA_7268
32#define UARTA_7278		REG_PHYS_ADDR_V7(0x40c000)
33#define UARTA_7364		REG_PHYS_ADDR(0x40b000)
34#define UARTA_7366		UARTA_7364
35#define UARTA_74371		REG_PHYS_ADDR(0x406b00)
36#define UARTA_7439		REG_PHYS_ADDR(0x40a900)
37#define UARTA_7445		REG_PHYS_ADDR(0x40ab00)
38
39#define UART_SHIFT		2
40
41#define checkuart(rp, rv, family_id, family) \
42		/* Load family id */ \
43		ldr	rp, =family_id ; \
44		/* Compare SUN_TOP_CTRL value against it */ \
45		cmp	rp, rv ; \
46		/* Passed test, load address */ \
47		ldreq	rp, =UARTA_##family ; \
48		/* Jump to save UART address */ \
49		beq	91f
50
51		.macro  addruart, rp, rv, tmp
52		adr	\rp, 99f		@ actual addr of 99f
53		ldr	\rv, [\rp]		@ linked addr is stored there
54		sub	\rv, \rv, \rp		@ offset between the two
55		ldr	\rp, [\rp, #4]		@ linked brcmstb_uart_config
56		sub	\tmp, \rp, \rv		@ actual brcmstb_uart_config
57		ldr	\rp, [\tmp]		@ Load brcmstb_uart_config
58		cmp	\rp, #1			@ needs initialization?
59		bne	100f			@ no; go load the addresses
60		mov	\rv, #0			@ yes; record init is done
61		str	\rv, [\tmp]
62
63		/* Check for V7 memory map if B53 */
64		mrc	p15, 0, \rv, c0, c0, 0	@ get Main ID register
65		ldr	\rp, =ARM_CPU_PART_MASK
66		and	\rv, \rv, \rp
67		ldr	\rp, =ARM_CPU_PART_BRAHMA_B53	@ check for B53 CPU
68		cmp	\rv, \rp
69		bne	10f
70
71		/* if PERIPHBASE doesn't overlap REG_PHYS_BASE use V7 map */
72		mrc	p15, 1, \rv, c15, c3, 0	@ get PERIPHBASE from CBAR
73		ands	\rv, \rv, #REG_PHYS_BASE
74		ldreq	\rp, =SUN_TOP_CTRL_BASE_V7
75
76		/* Check SUN_TOP_CTRL base */
7710:		ldrne	\rp, =SUN_TOP_CTRL_BASE	@ load SUN_TOP_CTRL PA
78		ldr	\rv, [\rp, #0]		@ get register contents
79ARM_BE8(	rev	\rv, \rv )
80		and	\rv, \rv, #0xffffff00	@ strip revision bits [7:0]
81
82		/* Chip specific detection starts here */
8320:		checkuart(\rp, \rv, 0x33900000, 3390)
8421:		checkuart(\rp, \rv, 0x72500000, 7250)
8522:		checkuart(\rp, \rv, 0x72600000, 7260)
8623:		checkuart(\rp, \rv, 0x72680000, 7268)
8724:		checkuart(\rp, \rv, 0x72710000, 7271)
8825:		checkuart(\rp, \rv, 0x73640000, 7364)
8926:		checkuart(\rp, \rv, 0x73660000, 7366)
9027:		checkuart(\rp, \rv, 0x07437100, 74371)
9128:		checkuart(\rp, \rv, 0x74390000, 7439)
9229:		checkuart(\rp, \rv, 0x74450000, 7445)
9330:		checkuart(\rp, \rv, 0x72780000, 7278)
94
95		/* No valid UART found */
9690:		mov	\rp, #0
97		/* fall through */
98
99		/* Record whichever UART we chose */
10091:		str	\rp, [\tmp, #4]		@ Store in brcmstb_uart_phys
101		cmp	\rp, #0			@ Valid UART address?
102		bne	92f			@ Yes, go process it
103		str	\rp, [\tmp, #8]		@ Store 0 in brcmstb_uart_virt
104		b	100f			@ Done
10592:		and     \rv, \rp, #0xffffff	@ offset within 16MB section
106		add	\rv, \rv, #REG_VIRT_BASE
107		str	\rv, [\tmp, #8]		@ Store in brcmstb_uart_virt
108		b	100f
109
110		.align
11199:		.word	.
112		.word	brcmstb_uart_config
113		.ltorg
114
115		/* Load previously selected UART address */
116100:		ldr	\rp, [\tmp, #4]		@ Load brcmstb_uart_phys
117		ldr	\rv, [\tmp, #8]		@ Load brcmstb_uart_virt
118		.endm
119
120		.macro	store, rd, rx:vararg
121ARM_BE8(	rev	\rd, \rd )
122		str	\rd, \rx
123		.endm
124
125		.macro	load, rd, rx:vararg
126		ldr	\rd, \rx
127ARM_BE8(	rev	\rd, \rd )
128		.endm
129
130		.macro	senduart,rd,rx
131		store	\rd, [\rx, #UART_TX << UART_SHIFT]
132		.endm
133
134		.macro	busyuart,rd,rx
1351002:		load	\rd, [\rx, #UART_LSR << UART_SHIFT]
136		and	\rd, \rd, #UART_LSR_TEMT | UART_LSR_THRE
137		teq	\rd, #UART_LSR_TEMT | UART_LSR_THRE
138		bne	1002b
139		.endm
140
141		.macro	waituart,rd,rx
142		.endm
143
144/*
145 * Storage for the state maintained by the macros above.
146 *
147 * In the kernel proper, this data is located in arch/arm/mach-bcm/brcmstb.c.
148 * That's because this header is included from multiple files, and we only
149 * want a single copy of the data. In particular, the UART probing code above
150 * assumes it's running using physical addresses. This is true when this file
151 * is included from head.o, but not when included from debug.o. So we need
152 * to share the probe results between the two copies, rather than having
153 * to re-run the probing again later.
154 *
155 * In the decompressor, we put the symbol/storage right here, since common.c
156 * isn't included in the decompressor build. This symbol gets put in .text
157 * even though it's really data, since .data is discarded from the
158 * decompressor. Luckily, .text is writeable in the decompressor, unless
159 * CONFIG_ZBOOT_ROM. That dependency is handled in arch/arm/Kconfig.debug.
160 */
161#if defined(ZIMAGE)
162brcmstb_uart_config:
163	/* Debug UART initialization required */
164	.word 1
165	/* Debug UART physical address */
166	.word 0
167	/* Debug UART virtual address */
168	.word 0
169#endif
170