[PATCH v2 2/5] ARM: BCM63XX: add low-level UART debug support

Florian Fainelli
2014-08-15T00:11:24Z

Broadcom BCM63xx DSL SoCs have a different UART implementation for which
we need specially crafted low-level debug assembly code to support. Add
support for this using the standard definitions provided in
include/linux/serial_bcm63xx.h (shared with their MIPS counterparts).

Signed-off-by: Florian Fainelli <f.fainelli-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org>
---
Changes in v2:
- rebased

arch/arm/Kconfig.debug | 18 ++++++++++++++++--
arch/arm/include/debug/bcm63xx.S | 33 +++++++++++++++++++++++++++++++++
2 files changed, 49 insertions(+), 2 deletions(-)
create mode 100644 arch/arm/include/debug/bcm63xx.S

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index b11ad54f8d17..07e9dd5eda26 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -122,6 +122,11 @@ choice
mobile SoCs in the Kona family of chips (e.g. bcm28155,
bcm11351, etc...)

+ config DEBUG_BCM63XX
+ bool "Kernel low-level debugging on BCM63XX UART"
+ depends on ARCH_BCM_63XX
+ select DEBUG_UART_BCM63XX
+
config DEBUG_BERLIN_UART
bool "Marvell Berlin SoC Debug UART"
depends on ARCH_BERLIN
@@ -1038,6 +1043,7 @@ config DEBUG_LL_INCLUDE
default "debug/vf.S" if DEBUG_VF_UART
default "debug/vt8500.S" if DEBUG_VT8500_UART0
default "debug/zynq.S" if DEBUG_ZYNQ_UART0 || DEBUG_ZYNQ_UART1
+ default "debug/bcm63xx.S" if DEBUG_UART_BCM63XX
default "mach/debug-macro.S"

# Compatibility options for PL01x
@@ -1057,6 +1063,10 @@ config DEBUG_UART_8250
ARCH_IOP33X || ARCH_IXP4XX || \
ARCH_LPC32XX || ARCH_MV78XX0 || ARCH_ORION5X || ARCH_RPC

+# Compatibility options for BCM63xx
+config DEBUG_UART_BCM63XX
+ def_bool ARCH_BCM_63XX
+
config DEBUG_UART_PHYS
hex "Physical base address of debug UART"
default 0x01c20000 if DEBUG_DAVINCI_DMx_UART0
@@ -1122,11 +1132,13 @@ config DEBUG_UART_PHYS
default 0xffc02000 if DEBUG_SOCFPGA_UART
default 0xffd82340 if ARCH_IOP13XX
default 0xfff36000 if DEBUG_HIGHBANK_UART
+ default 0xfffe8600 if DEBUG_UART_BCM63XX
default 0xfffff700 if ARCH_IOP33X
depends on DEBUG_LL_UART_8250 || DEBUG_LL_UART_PL01X || \
DEBUG_LL_UART_EFM32 || \
DEBUG_UART_8250 || DEBUG_UART_PL01X || \
- DEBUG_MSM_UART || DEBUG_QCOM_UARTDM || DEBUG_S3C24XX_UART
+ DEBUG_MSM_UART || DEBUG_QCOM_UARTDM || DEBUG_S3C24XX_UART || \
+ DEBUG_UART_BCM63XX

config DEBUG_UART_VIRT
hex "Virtual base address of debug UART"
@@ -1157,6 +1169,7 @@ config DEBUG_UART_VIRT
default 0xfa71e000 if DEBUG_QCOM_UARTDM
default 0xfb009000 if DEBUG_REALVIEW_STD_PORT
default 0xfb10c000 if DEBUG_REALVIEW_PB1176_PORT
+ default 0xfcfe8600 if DEBUG_UART_BCM63XX
default 0xfd000000 if ARCH_SPEAR3XX || ARCH_SPEAR6XX
default 0xfd000000 if ARCH_SPEAR13XX
default 0xfd012000 if ARCH_MV78XX0
@@ -1194,7 +1207,8 @@ config DEBUG_UART_VIRT
default DEBUG_UART_PHYS if !MMU
depends on DEBUG_LL_UART_8250 || DEBUG_LL_UART_PL01X || \
DEBUG_UART_8250 || DEBUG_UART_PL01X || \
- DEBUG_MSM_UART || DEBUG_QCOM_UARTDM || DEBUG_S3C24XX_UART
+ DEBUG_MSM_UART || DEBUG_QCOM_UARTDM || DEBUG_S3C24XX_UART || \
+ DEBUG_UART_BCM63XX

config DEBUG_UART_8250_SHIFT
int "Register offset shift for the 8250 debug UART"
diff --git a/arch/arm/include/debug/bcm63xx.S b/arch/arm/include/debug/bcm63xx.S
new file mode 100644
index 000000000000..e7164d570f44
--- /dev/null
+++ b/arch/arm/include/debug/bcm63xx.S
@@ -0,0 +1,33 @@
+/*
+ * Broadcom BCM63xx low-level UART debug
+ *
+ * Copyright (C) 2014 Broadcom Corporation
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/serial_bcm63xx.h>
+
+ .macro addruart, rp, rv, tmp
+ ldr \rp, =CONFIG_DEBUG_UART_PHYS
+ ldr \rv, =CONFIG_DEBUG_UART_VIRT
+ .endm
+
+ .macro senduart, rd, rx
+ /* word access do not work */
+ strb \rd, [\rx, #UART_FIFO_REG]
+ .endm
+
+ .macro waituart, rd, rx
+1001: ldr \rd, [\rx, #UART_IR_REG]
+ tst \rd, #(1 << UART_IR_TXEMPTY)
+ beq 1001b
+ .endm
+
+ .macro busyuart, rd, rx
+1002: ldr \rd, [\rx, #UART_IR_REG]
+ tst \rd, #(1 << UART_IR_TXTRESH)
+ beq 1002b
+ .endm