[PATCH v2] asm/debug_ll_ns16550.h: add parament divisor

[PATCH v2] asm/debug_ll_ns16550.h: add parament divisor

[Du Huanpeng]

From: duhuanpeng <u74147@gmail.com>

add a parameters for the assembly version for passing divisor,
and set the default value to DEBUG_LL_UART_ADDR when no parameter
is given.
now it is possiable to recalculate divisor in runtime to keep
the baudrate unchanged. when pll settings changed outside of barebox.
e.g. jtag.

Signed-off-by: duhuanpeng <u74147@gmail.com>
---
 arch/mips/include/asm/debug_ll_ns16550.h  | 4 ++--
 arch/riscv/include/asm/debug_ll_ns16550.h | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/mips/include/asm/debug_ll_ns16550.h b/arch/mips/include/asm/debug_ll_ns16550.h
index df58c4c..703bfae 100644
--- a/arch/mips/include/asm/debug_ll_ns16550.h
+++ b/arch/mips/include/asm/debug_ll_ns16550.h
@@ -58,14 +58,14 @@ static inline void PUTC_LL(char ch)
  * Macros for use in assembly language code
  */
 
-.macro	debug_ll_ns16550_init
+.macro	debug_ll_ns16550_init divisor=DEBUG_LL_UART_DIVISOR
 #ifdef CONFIG_DEBUG_LL
 	la	t0, DEBUG_LL_UART_ADDR
 
 	li	t1, UART_LCR_DLAB		/* DLAB on */
 	sb	t1, UART_LCR(t0)		/* Write it out */
 
-	li	t1, DEBUG_LL_UART_DIVISOR
+	li	t1, \divisor
 	sb	t1, UART_DLL(t0)		/* write low order byte */
 	srl	t1, t1, 8
 	sb	t1, UART_DLM(t0)		/* write high order byte */
diff --git a/arch/riscv/include/asm/debug_ll_ns16550.h b/arch/riscv/include/asm/debug_ll_ns16550.h
index e891cbd..f1c2ccb 100644
--- a/arch/riscv/include/asm/debug_ll_ns16550.h
+++ b/arch/riscv/include/asm/debug_ll_ns16550.h
@@ -88,14 +88,14 @@ static inline void debug_ll_ns16550_init(void)
  * Macros for use in assembly language code
  */
 
-.macro	debug_ll_ns16550_init
+.macro	debug_ll_ns16550_init divisor=DEBUG_LL_UART_DIVISOR
 #ifdef CONFIG_DEBUG_LL
 	li	t0, DEBUG_LL_UART_ADDR
 
 	li	t1, UART_LCR_DLAB		/* DLAB on */
 	UART_REG_S	t1, UART_LCR(t0)		/* Write it out */
 
-	li	t1, DEBUG_LL_UART_DIVISOR
+	li	t1, \divisor
 	UART_REG_S	t1, UART_DLL(t0)		/* write low order byte */
 	srl	t1, t1, 8
 	UART_REG_S	t1, UART_DLM(t0)		/* write high order byte */
-- 
2.7.4


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Re: [PATCH v2] asm/debug_ll_ns16550.h: add parament divisor

[Sascha Hauer]

On Sun, Sep 27, 2020 at 05:32:57PM +0800, Du Huanpeng wrote:
> From: duhuanpeng <u74147@gmail.com>
> 
> add a parameters for the assembly version for passing divisor,
> and set the default value to DEBUG_LL_UART_ADDR when no parameter
> is given.
> now it is possiable to recalculate divisor in runtime to keep
> the baudrate unchanged. when pll settings changed outside of barebox.
> e.g. jtag.
> 
> Signed-off-by: duhuanpeng <u74147@gmail.com>
> ---
>  arch/mips/include/asm/debug_ll_ns16550.h  | 4 ++--
>  arch/riscv/include/asm/debug_ll_ns16550.h | 4 ++--
>  2 files changed, 4 insertions(+), 4 deletions(-)

Applied, thanks

Sascha

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