Commit d0cf9d8a authored by Florian Fainelli's avatar Florian Fainelli
Browse files

ARM: brcmstb: Add earlyprintk support using run-time checks 



The SUN_TOP_CTRL_FAMILY_ID register  is at a fixed absolute address for
all of our supported chips, so utilize its value to determine what the
UARTA base address should be based on the value we read.

Since the code is called both during decompressor when the MMU is off,
and after the MMU has been turned on in the kernel, and we want to do
the lookup only once, we use the same technique as tegra.S and have a
shared storage location between the decompressor and the kernel.

Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
parent 29b4817d

arch/arm/Kconfig.debug

+7 −7
Original line number Diff line number Diff line
@@ -186,10 +186,11 @@ choice 
	config DEBUG_BRCMSTB_UART

		bool "Use BRCMSTB UART for low-level debug"

		depends on ARCH_BRCMSTB

		select DEBUG_UART_8250

		help

		  Say Y here if you want the debug print routines to direct

		  their output to the first serial port on these devices.

		  their output to the first serial port on these devices. The

		  UART physical and virtual address is automatically provided

		  based on the chip identification register value.



		  If you have a Broadcom STB chip and would like early print

		  messages to appear over the UART, select this option.
@@ -1430,6 +1431,7 @@ config DEBUG_LL_INCLUDE 
	default "debug/zynq.S" if DEBUG_ZYNQ_UART0 || DEBUG_ZYNQ_UART1

	default "debug/bcm63xx.S" if DEBUG_BCM63XX_UART

	default "debug/digicolor.S" if DEBUG_DIGICOLOR_UA0

	default "debug/brcmstb.S" if DEBUG_BRCMSTB_UART

	default "mach/debug-macro.S"



# Compatibility options for PL01x
@@ -1520,7 +1522,6 @@ config DEBUG_UART_PHYS 
	default 0xe6e60000 if DEBUG_RCAR_GEN2_SCIF0

	default 0xe8008000 if DEBUG_R7S72100_SCIF2

	default 0xf0000be0 if ARCH_EBSA110

	default 0xf040ab00 if DEBUG_BRCMSTB_UART

	default 0xf1012000 if DEBUG_MVEBU_UART0_ALTERNATE

	default 0xf1012100 if DEBUG_MVEBU_UART1_ALTERNATE

	default 0xf7fc9000 if DEBUG_BERLIN_UART
@@ -1604,7 +1605,6 @@ config DEBUG_UART_VIRT 
	default 0xfb009000 if DEBUG_REALVIEW_STD_PORT

	default 0xfb00c000 if DEBUG_AT91_SAMA5D4_USART3

	default 0xfb10c000 if DEBUG_REALVIEW_PB1176_PORT

	default 0xfc40ab00 if DEBUG_BRCMSTB_UART

	default 0xfc705000 if DEBUG_ZTE_ZX

	default 0xfcfe8600 if DEBUG_BCM63XX_UART

	default 0xfd000000 if DEBUG_SPEAR3XX || DEBUG_SPEAR13XX
@@ -1677,8 +1677,7 @@ config DEBUG_UART_8250_WORD 
		DEBUG_ALPINE_UART0 || \

		DEBUG_DAVINCI_DMx_UART0 || DEBUG_DAVINCI_DA8XX_UART1 || \

		DEBUG_DAVINCI_DA8XX_UART2 || \

		DEBUG_BCM_KONA_UART || DEBUG_RK32_UART2 || \

		DEBUG_BRCMSTB_UART

		DEBUG_BCM_KONA_UART || DEBUG_RK32_UART2



config DEBUG_UART_8250_PALMCHIP

	bool "8250 UART is Palmchip BK-310x"
@@ -1697,7 +1696,8 @@ config DEBUG_UNCOMPRESS 
	bool

	depends on ARCH_MULTIPLATFORM || PLAT_SAMSUNG || ARM_SINGLE_ARMV7M

	default y if DEBUG_LL && !DEBUG_OMAP2PLUS_UART && \

		     (!DEBUG_TEGRA_UART || !ZBOOT_ROM)

		     (!DEBUG_TEGRA_UART || !ZBOOT_ROM) && \

		     !DEBUG_BRCMSTB_UART

	help

	  This option influences the normal decompressor output for

	  multiplatform kernels.  Normally, multiplatform kernels disable

arch/arm/include/debug/brcmstb.S

0 → 100644
+145 −0
Original line number Diff line number Diff line 
/*

 * 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

arch/arm/mach-bcm/brcmstb.c

+16 −0
Original line number Diff line number Diff line
@@ -19,6 +19,22 @@ 
#include <asm/mach-types.h>

#include <asm/mach/arch.h>



/*

 * Storage for debug-macro.S's state.

 *

 * This must be in .data not .bss so that it gets initialized each time the

 * kernel is loaded. The data is declared here rather than debug-macro.S so

 * that multiple inclusions of debug-macro.S point at the same data.

 */

u32 brcmstb_uart_config[3] = {

	/* Debug UART initialization required */

	1,

	/* Debug UART physical address */

	0,

	/* Debug UART virtual address */

	0,

};



static void __init brcmstb_init_irq(void)

{

	irqchip_init();

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