Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
tjh.dev
kernel
os
linux
1/*
2 * Copyright (C) 2010,2011 Google, Inc.
3 * Copyright (C) 2011-2012 NVIDIA CORPORATION. All Rights Reserved.
4 *
5 * Author:
6 * Colin Cross <ccross@google.com>
7 * Erik Gilling <konkers@google.com>
8 * Doug Anderson <dianders@chromium.org>
9 * Stephen Warren <swarren@nvidia.com>
10 *
11 * Portions based on mach-omap2's debug-macro.S
12 * Copyright (C) 1994-1999 Russell King
13 *
14 * This software is licensed under the terms of the GNU General Public
15 * License version 2, as published by the Free Software Foundation, and
16 * may be copied, distributed, and modified under those terms.
17 *
18 * This program is distributed in the hope that it will be useful,
19 * but WITHOUT ANY WARRANTY; without even the implied warranty of
20 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
21 * GNU General Public License for more details.
22 *
23 */
24
25#include <linux/serial_reg.h>
26
27#define UART_SHIFT 2
28
29/* Physical addresses */
30#define TEGRA_CLK_RESET_BASE 0x60006000
31#define TEGRA_APB_MISC_BASE 0x70000000
32#define TEGRA_UARTA_BASE 0x70006000
33#define TEGRA_UARTB_BASE 0x70006040
34#define TEGRA_UARTC_BASE 0x70006200
35#define TEGRA_UARTD_BASE 0x70006300
36#define TEGRA_UARTE_BASE 0x70006400
37#define TEGRA_PMC_BASE 0x7000e400
38
39#define TEGRA_CLK_RST_DEVICES_L (TEGRA_CLK_RESET_BASE + 0x04)
40#define TEGRA_CLK_RST_DEVICES_H (TEGRA_CLK_RESET_BASE + 0x08)
41#define TEGRA_CLK_RST_DEVICES_U (TEGRA_CLK_RESET_BASE + 0x0c)
42#define TEGRA_CLK_OUT_ENB_L (TEGRA_CLK_RESET_BASE + 0x10)
43#define TEGRA_CLK_OUT_ENB_H (TEGRA_CLK_RESET_BASE + 0x14)
44#define TEGRA_CLK_OUT_ENB_U (TEGRA_CLK_RESET_BASE + 0x18)
45#define TEGRA_PMC_SCRATCH20 (TEGRA_PMC_BASE + 0xa0)
46#define TEGRA_APB_MISC_GP_HIDREV (TEGRA_APB_MISC_BASE + 0x804)
47
48/*
49 * Must be section-aligned since a section mapping is used early on.
50 * Must not overlap with regions in mach-tegra/io.c:tegra_io_desc[].
51 */
52#define UART_VIRTUAL_BASE 0xfe800000
53
54#define checkuart(rp, rv, lhu, bit, uart) \
55 /* Load address of CLK_RST register */ \
56 movw rp, #TEGRA_CLK_RST_DEVICES_##lhu & 0xffff ; \
57 movt rp, #TEGRA_CLK_RST_DEVICES_##lhu >> 16 ; \
58 /* Load value from CLK_RST register */ \
59 ldr rp, [rp, #0] ; \
60 /* Test UART's reset bit */ \
61 tst rp, #(1 << bit) ; \
62 /* If set, can't use UART; jump to save no UART */ \
63 bne 90f ; \
64 /* Load address of CLK_OUT_ENB register */ \
65 movw rp, #TEGRA_CLK_OUT_ENB_##lhu & 0xffff ; \
66 movt rp, #TEGRA_CLK_OUT_ENB_##lhu >> 16 ; \
67 /* Load value from CLK_OUT_ENB register */ \
68 ldr rp, [rp, #0] ; \
69 /* Test UART's clock enable bit */ \
70 tst rp, #(1 << bit) ; \
71 /* If clear, can't use UART; jump to save no UART */ \
72 beq 90f ; \
73 /* Passed all tests, load address of UART registers */ \
74 movw rp, #TEGRA_UART##uart##_BASE & 0xffff ; \
75 movt rp, #TEGRA_UART##uart##_BASE >> 16 ; \
76 /* Jump to save UART address */ \
77 b 91f
78
79 .macro addruart, rp, rv, tmp
80 adr \rp, 99f @ actual addr of 99f
81 ldr \rv, [\rp] @ linked addr is stored there
82 sub \rv, \rv, \rp @ offset between the two
83 ldr \rp, [\rp, #4] @ linked tegra_uart_config
84 sub \tmp, \rp, \rv @ actual tegra_uart_config
85 ldr \rp, [\tmp] @ Load tegra_uart_config
86 cmp \rp, #1 @ needs initialization?
87 bne 100f @ no; go load the addresses
88 mov \rv, #0 @ yes; record init is done
89 str \rv, [\tmp]
90
91#ifdef CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA
92 /* Check ODMDATA */
9310: movw \rp, #TEGRA_PMC_SCRATCH20 & 0xffff
94 movt \rp, #TEGRA_PMC_SCRATCH20 >> 16
95 ldr \rp, [\rp, #0] @ Load PMC_SCRATCH20
96 ubfx \rv, \rp, #18, #2 @ 19:18 are console type
97 cmp \rv, #2 @ 2 and 3 mean DCC, UART
98 beq 11f @ some boards swap the meaning
99 cmp \rv, #3 @ so accept either
100 bne 90f
10111: ubfx \rv, \rp, #15, #3 @ 17:15 are UART ID
102 cmp \rv, #0 @ UART 0?
103 beq 20f
104 cmp \rv, #1 @ UART 1?
105 beq 21f
106 cmp \rv, #2 @ UART 2?
107 beq 22f
108 cmp \rv, #3 @ UART 3?
109 beq 23f
110 cmp \rv, #4 @ UART 4?
111 beq 24f
112 b 90f @ invalid
113#endif
114
115#if defined(CONFIG_TEGRA_DEBUG_UARTA) || \
116 defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
117 /* Check UART A validity */
11820: checkuart(\rp, \rv, L, 6, A)
119#endif
120
121#if defined(CONFIG_TEGRA_DEBUG_UARTB) || \
122 defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
123 /* Check UART B validity */
12421: checkuart(\rp, \rv, L, 7, B)
125#endif
126
127#if defined(CONFIG_TEGRA_DEBUG_UARTC) || \
128 defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
129 /* Check UART C validity */
13022: checkuart(\rp, \rv, H, 23, C)
131#endif
132
133#if defined(CONFIG_TEGRA_DEBUG_UARTD) || \
134 defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
135 /* Check UART D validity */
13623: checkuart(\rp, \rv, U, 1, D)
137#endif
138
139#if defined(CONFIG_TEGRA_DEBUG_UARTE) || \
140 defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
141 /* Check UART E validity */
14224:
143 checkuart(\rp, \rv, U, 2, E)
144#endif
145
146 /* No valid UART found */
14790: mov \rp, #0
148 /* fall through */
149
150 /* Record whichever UART we chose */
15191: str \rp, [\tmp, #4] @ Store in tegra_uart_phys
152 cmp \rp, #0 @ Valid UART address?
153 bne 92f @ Yes, go process it
154 str \rp, [\tmp, #8] @ Store 0 in tegra_uart_virt
155 b 100f @ Done
15692: and \rv, \rp, #0xffffff @ offset within 1MB section
157 add \rv, \rv, #UART_VIRTUAL_BASE
158 str \rv, [\tmp, #8] @ Store in tegra_uart_virt
159 b 100f
160
161 .align
16299: .word .
163 .word tegra_uart_config
164 .ltorg
165
166 /* Load previously selected UART address */
167100: ldr \rp, [\tmp, #4] @ Load tegra_uart_phys
168 ldr \rv, [\tmp, #8] @ Load tegra_uart_virt
169 .endm
170
171/*
172 * Code below is swiped from <asm/hardware/debug-8250.S>, but add an extra
173 * check to make sure that the UART address is actually valid.
174 */
175
176 .macro senduart, rd, rx
177 cmp \rx, #0
178 strneb \rd, [\rx, #UART_TX << UART_SHIFT]
1791001:
180 .endm
181
182 .macro busyuart, rd, rx
183 cmp \rx, #0
184 beq 1002f
1851001: ldrb \rd, [\rx, #UART_LSR << UART_SHIFT]
186 and \rd, \rd, #UART_LSR_THRE
187 teq \rd, #UART_LSR_THRE
188 bne 1001b
1891002:
190 .endm
191
192 .macro waituart, rd, rx
193#ifdef FLOW_CONTROL
194 cmp \rx, #0
195 beq 1002f
1961001: ldrb \rd, [\rx, #UART_MSR << UART_SHIFT]
197 tst \rd, #UART_MSR_CTS
198 beq 1001b
1991002:
200#endif
201 .endm
202
203/*
204 * Storage for the state maintained by the macros above.
205 *
206 * In the kernel proper, this data is located in arch/arm/mach-tegra/tegra.c.
207 * That's because this header is included from multiple files, and we only
208 * want a single copy of the data. In particular, the UART probing code above
209 * assumes it's running using physical addresses. This is true when this file
210 * is included from head.o, but not when included from debug.o. So we need
211 * to share the probe results between the two copies, rather than having
212 * to re-run the probing again later.
213 *
214 * In the decompressor, we put the symbol/storage right here, since common.c
215 * isn't included in the decompressor build. This symbol gets put in .text
216 * even though it's really data, since .data is discarded from the
217 * decompressor. Luckily, .text is writeable in the decompressor, unless
218 * CONFIG_ZBOOT_ROM. That dependency is handled in arch/arm/Kconfig.debug.
219 */
220#if defined(ZIMAGE)
221tegra_uart_config:
222 /* Debug UART initialization required */
223 .word 1
224 /* Debug UART physical address */
225 .word 0
226 /* Debug UART virtual address */
227 .word 0
228#endif