xref: /openbmc/linux/arch/arm/include/debug/omap2plus.S (revision 55fd7e02)
1/* SPDX-License-Identifier: GPL-2.0-only */
2/*
3 * Debugging macro include header
4 *
5 *  Copyright (C) 1994-1999 Russell King
6 *  Moved from linux/arch/arm/kernel/debug.S by Ben Dooks
7*/
8
9#include <linux/serial_reg.h>
10
11/* External port on Zoom2/3 */
12#define ZOOM_UART_BASE		0x10000000
13#define ZOOM_UART_VIRT		0xfa400000
14
15#define OMAP_PORT_SHIFT		2
16#define ZOOM_PORT_SHIFT		1
17
18#define UART_OFFSET(addr)	((addr) & 0x00ffffff)
19
20		.pushsection .data
21		.align	2
22omap_uart_phys:	.word	0
23omap_uart_virt:	.word	0
24omap_uart_lsr:	.word	0
25		.popsection
26
27		.macro	addruart, rp, rv, tmp
28
29		/* Use omap_uart_phys/virt if already configured */
3010:		adr	\rp, 99f		@ get effective addr of 99f
31		ldr	\rv, [\rp]		@ get absolute addr of 99f
32		sub	\rv, \rv, \rp		@ offset between the two
33		ldr	\rp, [\rp, #4]		@ abs addr of omap_uart_phys
34		sub	\tmp, \rp, \rv		@ make it effective
35		ldr	\rp, [\tmp, #0]		@ omap_uart_phys
36		ldr	\rv, [\tmp, #4]		@ omap_uart_virt
37		cmp	\rp, #0			@ is port configured?
38		cmpne	\rv, #0
39		bne	100f			@ already configured
40
41		/* Configure the UART offset from the phys/virt base */
42#ifdef CONFIG_DEBUG_ZOOM_UART
43		ldr	\rp, =ZOOM_UART_BASE
44		str	\rp, [\tmp, #0]		@ omap_uart_phys
45		ldr	\rp, =ZOOM_UART_VIRT
46		str	\rp, [\tmp, #4]		@ omap_uart_virt
47		mov	\rp, #(UART_LSR << ZOOM_PORT_SHIFT)
48		str	\rp, [\tmp, #8]		@ omap_uart_lsr
49#endif
50		b	10b
51
52		.align
5399:		.word	.
54		.word	omap_uart_phys
55		.ltorg
56
57100:		/* Pass the UART_LSR reg address */
58		ldr	\tmp, [\tmp, #8]	@ omap_uart_lsr
59		add	\rp, \rp, \tmp
60		add	\rv, \rv, \tmp
61		.endm
62
63		.macro	senduart,rd,rx
64		orr	\rd, \rd, \rx, lsl #24	@ preserve LSR reg offset
65		bic	\rx, \rx, #0xff		@ get base (THR) reg address
66		strb	\rd, [\rx]		@ send lower byte of rd
67		orr	\rx, \rx, \rd, lsr #24	@ restore original rx (LSR)
68		bic	\rd, \rd, #(0xff << 24)	@ restore original rd
69		.endm
70
71		.macro	busyuart,rd,rx
721001:		ldrb	\rd, [\rx]		@ rx contains UART_LSR address
73		and	\rd, \rd, #(UART_LSR_TEMT | UART_LSR_THRE)
74		teq	\rd, #(UART_LSR_TEMT | UART_LSR_THRE)
75		bne	1001b
76		.endm
77
78		.macro	waituart,rd,rx
79		.endm
80