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Diffstat (limited to 'arch/arm/include/debug/brcmstb.S')
| -rw-r--r-- | arch/arm/include/debug/brcmstb.S | 145 |
1 files changed, 145 insertions, 0 deletions
diff --git a/arch/arm/include/debug/brcmstb.S b/arch/arm/include/debug/brcmstb.S new file mode 100644 index 000000000000..9113d7b33ae0 --- /dev/null +++ b/arch/arm/include/debug/brcmstb.S @@ -0,0 +1,145 @@ +/* + * Copyright (C) 2016 Broadcom + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation version 2. + * + * This program is distributed "as is" WITHOUT ANY WARRANTY of any + * kind, whether express or implied; 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> + +/* Physical register offset and virtual register offset */ +#define REG_PHYS_BASE 0xf0000000 +#define REG_VIRT_BASE 0xfc000000 +#define REG_PHYS_ADDR(x) ((x) + REG_PHYS_BASE) + +/* Product id can be read from here */ +#define SUN_TOP_CTRL_BASE REG_PHYS_ADDR(0x404000) + +#define UARTA_3390 REG_PHYS_ADDR(0x40a900) +#define UARTA_7250 REG_PHYS_ADDR(0x40b400) +#define UARTA_7268 REG_PHYS_ADDR(0x40c000) +#define UARTA_7271 UARTA_7268 +#define UARTA_7364 REG_PHYS_ADDR(0x40b000) +#define UARTA_7366 UARTA_7364 +#define UARTA_74371 REG_PHYS_ADDR(0x406b00) +#define UARTA_7439 REG_PHYS_ADDR(0x40a900) +#define UARTA_7445 REG_PHYS_ADDR(0x40ab00) + +#define UART_SHIFT 2 + +#define checkuart(rp, rv, family_id, family) \ + /* Load family id */ \ + ldr rp, =family_id ; \ + /* Compare SUN_TOP_CTRL value against it */ \ + cmp rp, rv ; \ + /* Passed test, load address */ \ + ldreq rp, =UARTA_##family ; \ + /* Jump to save UART address */ \ + beq 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 brcmstb_uart_config + sub \tmp, \rp, \rv @ actual brcmstb_uart_config + ldr \rp, [\tmp] @ Load brcmstb_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] + + /* Check SUN_TOP_CTRL base */ + ldr \rp, =SUN_TOP_CTRL_BASE @ load SUN_TOP_CTRL PA + ldr \rv, [\rp, #0] @ get register contents + and \rv, \rv, #0xffffff00 @ strip revision bits [7:0] + + /* Chip specific detection starts here */ +20: checkuart(\rp, \rv, 0x33900000, 3390) +21: checkuart(\rp, \rv, 0x72500000, 7250) +22: checkuart(\rp, \rv, 0x72680000, 7268) +23: checkuart(\rp, \rv, 0x72710000, 7271) +24: checkuart(\rp, \rv, 0x73640000, 7364) +25: checkuart(\rp, \rv, 0x73660000, 7366) +26: checkuart(\rp, \rv, 0x07437100, 74371) +27: checkuart(\rp, \rv, 0x74390000, 7439) +28: checkuart(\rp, \rv, 0x74450000, 7445) + + /* No valid UART found */ +90: mov \rp, #0 + /* fall through */ + + /* Record whichever UART we chose */ +91: str \rp, [\tmp, #4] @ Store in brcmstb_uart_phys + cmp \rp, #0 @ Valid UART address? + bne 92f @ Yes, go process it + str \rp, [\tmp, #8] @ Store 0 in brcmstb_uart_virt + b 100f @ Done +92: and \rv, \rp, #0xffffff @ offset within 16MB section + add \rv, \rv, #REG_VIRT_BASE + str \rv, [\tmp, #8] @ Store in brcmstb_uart_virt + b 100f + + .align +99: .word . + .word brcmstb_uart_config + .ltorg + + /* Load previously selected UART address */ +100: ldr \rp, [\tmp, #4] @ Load brcmstb_uart_phys + ldr \rv, [\tmp, #8] @ Load brcmstb_uart_virt + .endm + + .macro store, rd, rx:vararg + str \rd, \rx + .endm + + .macro load, rd, rx:vararg + ldr \rd, \rx + .endm + + .macro senduart,rd,rx + store \rd, [\rx, #UART_TX << UART_SHIFT] + .endm + + .macro busyuart,rd,rx +1002: load \rd, [\rx, #UART_LSR << UART_SHIFT] + and \rd, \rd, #UART_LSR_TEMT | UART_LSR_THRE + teq \rd, #UART_LSR_TEMT | UART_LSR_THRE + bne 1002b + .endm + + .macro waituart,rd,rx + .endm + +/* + * Storage for the state maintained by the macros above. + * + * In the kernel proper, this data is located in arch/arm/mach-bcm/brcmstb.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) +brcmstb_uart_config: + /* Debug UART initialization required */ + .word 1 + /* Debug UART physical address */ + .word 0 + /* Debug UART virtual address */ + .word 0 +#endif |