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Diffstat (limited to 'arch/arm/include/debug/tegra.S')
| -rw-r--r-- | arch/arm/include/debug/tegra.S | 226 |
1 files changed, 226 insertions, 0 deletions
diff --git a/arch/arm/include/debug/tegra.S b/arch/arm/include/debug/tegra.S new file mode 100644 index 000000000..3bc80599c --- /dev/null +++ b/arch/arm/include/debug/tegra.S @@ -0,0 +1,226 @@ +/* + * 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 |