From e7ac471d5ceb955c050c9330afd56d1cdb0da52f Mon Sep 17 00:00:00 2001 From: Chen Baozi Date: Tue, 13 Aug 2013 19:14:22 +0800 Subject: xen/arm: add 8250 compatible UART support for early_printk Both OMAP5 and sun6i/sun7i SoCs share this UART driver for early_printk. Signed-off-by: Chen Baozi Acked-by: Ian Campbell --- docs/misc/arm/early-printk.txt | 3 +++ xen/arch/arm/Rules.mk | 16 +++++++++++++++ xen/arch/arm/arm32/debug-8250.inc | 41 +++++++++++++++++++++++++++++++++++++++ 3 files changed, 60 insertions(+) create mode 100644 xen/arch/arm/arm32/debug-8250.inc diff --git a/docs/misc/arm/early-printk.txt b/docs/misc/arm/early-printk.txt index fbc32087d8..14317519ff 100644 --- a/docs/misc/arm/early-printk.txt +++ b/docs/misc/arm/early-printk.txt @@ -13,6 +13,9 @@ where mach is the name of the machine: - exynos5250: printk with the second UART - midway: printk with the pl011 on Calxeda Midway processors - fastmodel: printk on ARM Fastmodel software emulators + - omap5432: printk with UART3 on TI OMAP5432 processors + - sun6i: printk with 8250 on Allwinner A31 processors + - sun7i: printk with 8250 on Allwinner A20 processors The base address and baud rate is hardcoded in xen/arch/arm/Rules.mk, see there when adding support for new machines. diff --git a/xen/arch/arm/Rules.mk b/xen/arch/arm/Rules.mk index d80dfce584..bd79b269af 100644 --- a/xen/arch/arm/Rules.mk +++ b/xen/arch/arm/Rules.mk @@ -62,6 +62,21 @@ EARLY_PRINTK_INC := pl011 EARLY_PRINTK_BAUD := 115200 EARLY_UART_BASE_ADDRESS := 0xfff36000 endif +ifeq ($(CONFIG_EARLY_PRINTK), omap5432) +EARLY_PRINTK_INC := 8250 +EARLY_UART_BASE_ADDRESS := 0x48020000 +EARLY_UART_REG_SHIFT := 2 +endif +ifeq ($(CONFIG_EARLY_PRINTK), sun6i) +EARLY_PRINTK_INC := 8250 +EARLY_UART_BASE_ADDRESS := 0x01c28000 +EARLY_UART_REG_SHIFT := 2 +endif +ifeq ($(CONFIG_EARLY_PRINTK), sun7i) +EARLY_PRINTK_INC := 8250 +EARLY_UART_BASE_ADDRESS := 0x01c28000 +EARLY_UART_REG_SHIFT := 2 +endif ifneq ($(EARLY_PRINTK_INC),) EARLY_PRINTK := y @@ -72,4 +87,5 @@ CFLAGS-$(EARLY_PRINTK_INIT_UART) += -DEARLY_PRINTK_INIT_UART CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK_INC=\"debug-$(EARLY_PRINTK_INC).inc\" CFLAGS-$(EARLY_PRINTK) += -DEARLY_PRINTK_BAUD=$(EARLY_PRINTK_BAUD) CFLAGS-$(EARLY_PRINTK) += -DEARLY_UART_BASE_ADDRESS=$(EARLY_UART_BASE_ADDRESS) +CFLAGS-$(EARLY_PRINTK) += -DEARLY_UART_REG_SHIFT=$(EARLY_UART_REG_SHIFT) endif diff --git a/xen/arch/arm/arm32/debug-8250.inc b/xen/arch/arm/arm32/debug-8250.inc new file mode 100644 index 0000000000..eb25882400 --- /dev/null +++ b/xen/arch/arm/arm32/debug-8250.inc @@ -0,0 +1,41 @@ +/* + * xen/arch/arm/arm32/debug-8250.inc + * + * 8250 specific debug code + * + * 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; either version 2 of the License, or + * (at your option) any later version. + * + * 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 + +/* 8250 UART wait UART to be ready to transmit + * rb: register which contains the UART base address + * rc: scratch register */ +.macro early_uart_ready rb rc +1: + ldr \rc, [\rb, #(UART_LSR << EARLY_UART_REG_SHIFT)] /* Read LSR */ + tst \rc, #UART_LSR_THRE /* Check Xmit holding register flag */ + beq 1b /* Wait for the UART to be ready */ +.endm + +/* 8250 UART transmit character + * rb: register which contains the UART base address + * rt: register which contains the character to transmit */ +.macro early_uart_transmit rb rt + str \rt, [\rb, #UART_THR] /* Write Transmit buffer */ +.endm + +/* + * Local variables: + * mode: ASM + * indent-tabs-mode: nil + * End: + */ -- cgit v1.2.3