/*
* Copyright (C) 2010,2011 Google, Inc.
* Copyright (C) 2011-2012 NVIDIA CORPORATION. All Rights Reserved.
*
* Author:
* Colin Cross <ccross@google.com>
* Erik Gilling <konkers@google.com>
* Doug Anderson <dianders@chromium.org>
* Stephen Warren <swarren@nvidia.com>
*
* Portions based on mach-omap2's debug-macro.S
* Copyright (C) 1994-1999 Russell King
*
* This software is licensed under the terms of the GNU General Public
* License version 2, as published by the Free Software Foundation, and
* may be copied, distributed, and modified under those terms.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
*/
#include <linux/serial_reg.h>
#define UART_SHIFT 2
/* Physical addresses */
#define TEGRA_CLK_RESET_BASE 0x60006000
#define TEGRA_APB_MISC_BASE 0x70000000
#define TEGRA_UARTA_BASE 0x70006000
#define TEGRA_UARTB_BASE 0x70006040
#define TEGRA_UARTC_BASE 0x70006200
#define TEGRA_UARTD_BASE 0x70006300
#define TEGRA_UARTE_BASE 0x70006400
#define TEGRA_PMC_BASE 0x7000e400
#define TEGRA_CLK_RST_DEVICES_L (TEGRA_CLK_RESET_BASE + 0x04)
#define TEGRA_CLK_RST_DEVICES_H (TEGRA_CLK_RESET_BASE + 0x08)
#define TEGRA_CLK_RST_DEVICES_U (TEGRA_CLK_RESET_BASE + 0x0c)
#define TEGRA_CLK_OUT_ENB_L (TEGRA_CLK_RESET_BASE + 0x10)
#define TEGRA_CLK_OUT_ENB_H (TEGRA_CLK_RESET_BASE + 0x14)
#define TEGRA_CLK_OUT_ENB_U (TEGRA_CLK_RESET_BASE + 0x18)
#define TEGRA_PMC_SCRATCH20 (TEGRA_PMC_BASE + 0xa0)
#define TEGRA_APB_MISC_GP_HIDREV (TEGRA_APB_MISC_BASE + 0x804)
/*
* Must be section-aligned since a section mapping is used early on.
* Must not overlap with regions in mach-tegra/io.c:tegra_io_desc[].
*/
#define UART_VIRTUAL_BASE 0xfe800000
#define checkuart(rp, rv, lhu, bit, uart) \
/* Load address of CLK_RST register */ \
ldr rp, =TEGRA_CLK_RST_DEVICES_##lhu ; \
/* Load value from CLK_RST register */ \
ldr rp, [rp, #0] ; \
/* Test UART's reset bit */ \
tst rp, #(1 << bit) ; \
/* If set, can't use UART; jump to save no UART */ \
bne 90f ; \
/* Load address of CLK_OUT_ENB register */ \
ldr rp, =TEGRA_CLK_OUT_ENB_##lhu ; \
/* Load value from CLK_OUT_ENB register */ \
ldr rp, [rp, #0] ; \
/* Test UART's clock enable bit */ \
tst rp, #(1 << bit) ; \
/* If clear, can't use UART; jump to save no UART */ \
beq 90f ; \
/* Passed all tests, load address of UART registers */ \
ldr rp, =TEGRA_UART##uart##_BASE ; \
/* Jump to save UART address */ \
b 91f
.macro addruart, rp, rv, tmp
adr \rp, 99f @ actual addr of 99f
ldr \rv, [\rp] @ linked addr is stored there
sub \rv, \rv, \rp @ offset between the two
ldr \rp, [\rp, #4] @ linked tegra_uart_config
sub \tmp, \rp, \rv @ actual tegra_uart_config
ldr \rp, [\tmp] @ Load tegra_uart_config
cmp \rp, #1 @ needs initialization?
bne 100f @ no; go load the addresses
mov \rv, #0 @ yes; record init is done
str \rv, [\tmp]
#ifdef CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA
/* Check ODMDATA */
10: ldr \rp, =TEGRA_PMC_SCRATCH20
ldr \rp, [\rp, #0] @ Load PMC_SCRATCH20
lsr \rv, \rp, #18 @ 19:18 are console type
and \rv, \rv, #3
cmp \rv, #2 @ 2 and 3 mean DCC, UART
beq 11f @ some boards swap the meaning
cmp \rv, #3 @ so accept either
bne 90f
11: lsr \rv, \rp, #15 @ 17:15 are UART ID
and \rv, #7
cmp \rv, #0 @ UART 0?
beq 20f
cmp \rv, #1 @ UART 1?
beq 21f
cmp \rv, #2 @ UART 2?
beq 22f
cmp \rv, #3 @ UART 3?
beq 23f
cmp \rv, #4 @ UART 4?
beq 24f
b 90f @ invalid
#endif
#if defined(CONFIG_TEGRA_DEBUG_UARTA) || \
defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
/* Check UART A validity */
20: checkuart(\rp, \rv, L, 6, A)
#endif
#if defined(CONFIG_TEGRA_DEBUG_UARTB) || \
defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
/* Check UART B validity */
21: checkuart(\rp, \rv, L, 7, B)
#endif
#if defined(CONFIG_TEGRA_DEBUG_UARTC) || \
defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
/* Check UART C validity */
22: checkuart(\rp, \rv, H, 23, C)
#endif
#if defined(CONFIG_TEGRA_DEBUG_UARTD) || \
defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
/* Check UART D validity */
23: checkuart(\rp, \rv, U, 1, D)
#endif
#if defined(CONFIG_TEGRA_DEBUG_UARTE) || \
defined(CONFIG_TEGRA_DEBUG_UART_AUTO_ODMDATA)
/* Check UART E validity */
24:
checkuart(\rp, \rv, U, 2, E)
#endif
/* No valid UART found */
90: mov \rp, #0
/* fall through */
/* Record whichever UART we chose */
91: str \rp, [\tmp, #4] @ Store in tegra_uart_phys
cmp \rp, #0 @ Valid UART address?
bne 92f @ Yes, go process it
str \rp, [\tmp, #8] @ Store 0 in tegra_uart_virt
b 100f @ Done
92: and \rv, \rp, #0xffffff @ offset within 1MB section
add \rv, \rv, #UART_VIRTUAL_BASE
str \rv, [\tmp, #8] @ Store in tegra_uart_virt
b 100f
.align
99: .word .
.word tegra_uart_config
.ltorg
/* Load previously selected UART address */
100: ldr \rp, [\tmp, #4] @ Load tegra_uart_phys
ldr \rv, [\tmp, #8] @ Load tegra_uart_virt
.endm
/*
* Code below is swiped from <asm/hardware/debug-8250.S>, but add an extra
* check to make sure that the UART address is actually valid.
*/
.macro senduart, rd, rx
cmp \rx, #0
strneb \rd, [\rx, #UART_TX << UART_SHIFT]
1001:
.endm
.macro busyuart, rd, rx
cmp \rx, #0
beq 1002f
1001: ldrb \rd, [\rx, #UART_LSR << UART_SHIFT]
and \rd, \rd, #UART_LSR_THRE
teq \rd, #UART_LSR_THRE
bne 1001b
1002:
.endm
.macro waituart, rd, rx
#ifdef FLOW_CONTROL
cmp \rx, #0
beq 1002f
1001: ldrb \rd, [\rx, #UART_MSR << UART_SHIFT]
tst \rd, #UART_MSR_CTS
beq 1001b
1002:
#endif
.endm
/*
* Storage for the state maintained by the macros above.
*
* In the kernel proper, this data is located in arch/arm/mach-tegra/tegra.c.
* That's because this header is included from multiple files, and we only
* want a single copy of the data. In particular, the UART probing code above
* assumes it's running using physical addresses. This is true when this file
* is included from head.o, but not when included from debug.o. So we need
* to share the probe results between the two copies, rather than having
* to re-run the probing again later.
*
* In the decompressor, we put the symbol/storage right here, since common.c
* isn't included in the decompressor build. This symbol gets put in .text
* even though it's really data, since .data is discarded from the
* decompressor. Luckily, .text is writeable in the decompressor, unless
* CONFIG_ZBOOT_ROM. That dependency is handled in arch/arm/Kconfig.debug.
*/
#if defined(ZIMAGE)
tegra_uart_config:
/* Debug UART initialization required */
.word 1
/* Debug UART physical address */
.word 0
/* Debug UART virtual address */
.word 0
#endif