diff mbox

[02/10] ARM: zx: add low level debug support

Message ID 1426333785-3952-3-git-send-email-jun.nie@linaro.org (mailing list archive)
State New, archived
Headers show

Commit Message

Jun Nie March 14, 2015, 11:49 a.m. UTC 
Use the UART0 peripheral for low level debug. Only the UART port 0 is
currently supported.

Signed-off-by: Jun Nie <jun.nie@linaro.org>
---
 arch/arm/Kconfig.debug      | 12 ++++++++++++
 arch/arm/include/debug/zx.S | 35 +++++++++++++++++++++++++++++++++++
 2 files changed, 47 insertions(+)
 create mode 100644 arch/arm/include/debug/zx.S

Comments

Matthias Brugger March 15, 2015, 10:44 p.m. UTC | #1 
On 14/03/15 12:49, Jun Nie wrote:
> Use the UART0 peripheral for low level debug. Only the UART port 0 is
> currently supported.
> 
> Signed-off-by: Jun Nie <jun.nie@linaro.org>
> ---
>  arch/arm/Kconfig.debug      | 12 ++++++++++++
>  arch/arm/include/debug/zx.S | 35 +++++++++++++++++++++++++++++++++++
>  2 files changed, 47 insertions(+)
>  create mode 100644 arch/arm/include/debug/zx.S
> 
> diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
> index 970de75..b2a0e9a 100644
> --- a/arch/arm/Kconfig.debug
> +++ b/arch/arm/Kconfig.debug
> @@ -1169,6 +1169,17 @@ choice
>  		  For more details about semihosting, please see
>  		  chapter 8 of DUI0203I_rvct_developer_guide.pdf from ARM Ltd.
>  
> +	config DEBUG_ZTE_ZX
> +		bool "Use ZTE ZX UART"
> +		depends on ARCH_ZX
> +		help
> +		  Say Y here if you are enabling ZTE ZX296702 SOC and need
> +		  debug uart support.
> +
> +		  This option is preferred over the platform specific
> +		  options; the platform specific options are deprecated
> +		  and will be soon removed.
> +
>  	config DEBUG_LL_UART_8250
>  		bool "Kernel low-level debugging via 8250 UART"
>  		help
> @@ -1315,6 +1326,7 @@ config DEBUG_LL_INCLUDE
>  	default "debug/vexpress.S" if DEBUG_VEXPRESS_UART0_DETECT
>  	default "debug/vf.S" if DEBUG_VF_UART
>  	default "debug/vt8500.S" if DEBUG_VT8500_UART0
> +	default "debug/zx.S" if DEBUG_ZTE_ZX
>  	default "debug/zynq.S" if DEBUG_ZYNQ_UART0 || DEBUG_ZYNQ_UART1
>  	default "debug/bcm63xx.S" if DEBUG_UART_BCM63XX
>  	default "debug/digicolor.S" if DEBUG_DIGICOLOR_UA0
> diff --git a/arch/arm/include/debug/zx.S b/arch/arm/include/debug/zx.S
> new file mode 100644
> index 0000000..aa745ac
> --- /dev/null
> +++ b/arch/arm/include/debug/zx.S
> @@ -0,0 +1,35 @@
> +/*
> + * Debugging macro include header
> + *
> + * 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.
> + *
> + */
> +
> +#define UART01x_DR              0x04    /* Data read or write */
> +#define UART01x_FR              0x14    /* Flag register (Read only) */
> +
> +#define UART01x_FR_TXFF         0x020
> +
> +
> +#define UART0_PADDR		0x09405000
> +#define UART0_VADDR		0xfc705000

Why don't you use CONFIG_DEBUG_UART_VIRT and CONFIG_DEBUG_UART_PHYS?

> +
> +		.macro	addruart, rp, rv, tmp
> +		ldr	\rp, =UART0_PADDR	@ physical
> +		ldr	\rv, =UART0_VADDR	@ virtual
> +		.endm
> +
> +		.macro	senduart,rd,rx
> +		strb	\rd, [\rx, #UART01x_DR]
> +		.endm
> +
> +		.macro	waituart,rd,rx
> +		.endm
> +
> +		.macro  busyuart,rd,rx
> +1001:		ldr	\rd, [\rx, #UART01x_FR]
> +		tst	\rd, #UART01x_FR_TXFF
> +		bne	1001b
> +		.endm
>
Russell King - ARM Linux March 15, 2015, 10:48 p.m. UTC | #2 
On Sat, Mar 14, 2015 at 07:49:37PM +0800, Jun Nie wrote:
> Use the UART0 peripheral for low level debug. Only the UART port 0 is
> currently supported.

None of this code is necessary - in fact, you don't have to add one line
of assembly code what so ever.

We have generic PL011 debug support.  Please use that, you only need to
ensure that the phys and virtual addresses are properly configured in
arch/arm/Kconfig.debug and that the appropriate symbol is selected.

Thanks.
diff mbox

Patch

diff --git a/arch/arm/Kconfig.debug b/arch/arm/Kconfig.debug
index 970de75..b2a0e9a 100644
--- a/arch/arm/Kconfig.debug
+++ b/arch/arm/Kconfig.debug
@@ -1169,6 +1169,17 @@  choice
 		  For more details about semihosting, please see
 		  chapter 8 of DUI0203I_rvct_developer_guide.pdf from ARM Ltd.
 
+	config DEBUG_ZTE_ZX
+		bool "Use ZTE ZX UART"
+		depends on ARCH_ZX
+		help
+		  Say Y here if you are enabling ZTE ZX296702 SOC and need
+		  debug uart support.
+
+		  This option is preferred over the platform specific
+		  options; the platform specific options are deprecated
+		  and will be soon removed.
+
 	config DEBUG_LL_UART_8250
 		bool "Kernel low-level debugging via 8250 UART"
 		help
@@ -1315,6 +1326,7 @@  config DEBUG_LL_INCLUDE
 	default "debug/vexpress.S" if DEBUG_VEXPRESS_UART0_DETECT
 	default "debug/vf.S" if DEBUG_VF_UART
 	default "debug/vt8500.S" if DEBUG_VT8500_UART0
+	default "debug/zx.S" if DEBUG_ZTE_ZX
 	default "debug/zynq.S" if DEBUG_ZYNQ_UART0 || DEBUG_ZYNQ_UART1
 	default "debug/bcm63xx.S" if DEBUG_UART_BCM63XX
 	default "debug/digicolor.S" if DEBUG_DIGICOLOR_UA0
diff --git a/arch/arm/include/debug/zx.S b/arch/arm/include/debug/zx.S
new file mode 100644
index 0000000..aa745ac
--- /dev/null
+++ b/arch/arm/include/debug/zx.S
@@ -0,0 +1,35 @@ 
+/*
+ * Debugging macro include header
+ *
+ * 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.
+ *
+ */
+
+#define UART01x_DR              0x04    /* Data read or write */
+#define UART01x_FR              0x14    /* Flag register (Read only) */
+
+#define UART01x_FR_TXFF         0x020
+
+
+#define UART0_PADDR		0x09405000
+#define UART0_VADDR		0xfc705000
+
+		.macro	addruart, rp, rv, tmp
+		ldr	\rp, =UART0_PADDR	@ physical
+		ldr	\rv, =UART0_VADDR	@ virtual
+		.endm
+
+		.macro	senduart,rd,rx
+		strb	\rd, [\rx, #UART01x_DR]
+		.endm
+
+		.macro	waituart,rd,rx
+		.endm
+
+		.macro  busyuart,rd,rx
+1001:		ldr	\rd, [\rx, #UART01x_FR]
+		tst	\rd, #UART01x_FR_TXFF
+		bne	1001b
+		.endm