* [PATCH] MIPS: loongson1: enable to run from spi flash
@ 2020-09-11 12:33 Du Huanpeng
2020-09-11 12:33 ` [PATCH] MIPS: DEBUG_LL_UART_DIVISOR is 0, use a0 instead Du Huanpeng
0 siblings, 1 reply; 7+ messages in thread
From: Du Huanpeng @ 2020-09-11 12:33 UTC (permalink / raw)
To: barebox; +Cc: Du Huanpeng
initial pll, ddr2 controller, calculate perscale divisor for uart.
Signed-off-by: Du Huanpeng <u74147@gmail.com>
---
arch/mips/boards/loongson-ls1b/lowlevel.S | 33 ++++-
arch/mips/mach-loongson/include/mach/debug_ll.h | 1 +
.../include/mach/debug_ll_loongson1.h | 15 ++
.../include/mach/pbl_ll_init_loongson1.h | 162 +++++++++++++++++++++
arch/mips/mach-loongson/include/mach/pbl_macros.h | 81 +++++++++++
5 files changed, 291 insertions(+), 1 deletion(-)
create mode 100644 arch/mips/mach-loongson/include/mach/debug_ll_loongson1.h
create mode 100644 arch/mips/mach-loongson/include/mach/pbl_ll_init_loongson1.h
create mode 100644 arch/mips/mach-loongson/include/mach/pbl_macros.h
diff --git a/arch/mips/boards/loongson-ls1b/lowlevel.S b/arch/mips/boards/loongson-ls1b/lowlevel.S
index c533df3..af6ad54 100644
--- a/arch/mips/boards/loongson-ls1b/lowlevel.S
+++ b/arch/mips/boards/loongson-ls1b/lowlevel.S
@@ -1,6 +1,7 @@
/* SPDX-License-Identifier: GPL-2.0-only */
/*
* Copyright (C) 2014 Antony Pavlov <antonynpavlov@gmail.com>
+ * Copyright (C) 2020 Du Huanpeng <duhuanpegn@gmail.com>
*/
#define BOARD_PBL_START start_loongson_ls1b
@@ -11,15 +12,45 @@
#include <asm/pbl_nmon.h>
#include <linux/sizes.h>
+#include <mach/pbl_macros.h>
+#include <mach/pbl_ll_init_loongson1.h>
+
+
ENTRY_FUNCTION(BOARD_PBL_START)
mips_barebox_10h
mips_disable_interrupts
- debug_ll_ns16550_init
+ pbl_blt 0xbf000000 168f t0
+ pbl_loongson1_pll
+
+ pbl_loongson1_uart_enable
+ pbl_loongson1_calc_prescale 115200
+ move a0, v0
+ debug_ll_ns16550_init
+ debug_ll_ns16550_outnl
debug_ll_outc '.'
debug_ll_ns16550_outnl
+ debug_ll_outc '1'
+
+ pbl_loongson1_remap
+ debug_ll_outc '2'
+
+ pbl_loongson1_ddr2_init
+ pbl_probe_mem t0, t1, KSEG1
+ bne t0, t1, .
+ nop
+
+ debug_ll_outc '3'
+
+ mips_cache_reset
+ dcache_enable
+ debug_ll_outc '4'
+
+168:
+ debug_ll_outc '5'
+ debug_ll_ns16550_outnl
ENTRY_FUNCTION_END(BOARD_PBL_START, loongson_ls1b, SZ_64M)
diff --git a/arch/mips/mach-loongson/include/mach/debug_ll.h b/arch/mips/mach-loongson/include/mach/debug_ll.h
index c2d6edb..39d791a 100644
--- a/arch/mips/mach-loongson/include/mach/debug_ll.h
+++ b/arch/mips/mach-loongson/include/mach/debug_ll.h
@@ -9,6 +9,7 @@
/** @file
* This File contains declaration for early output support
*/
+#include <mach/debug_ll_loongson1.h>
#include <asm/debug_ll_ns16550.h>
#endif /* __MACH_LOONGSON_DEBUG_LL__ */
diff --git a/arch/mips/mach-loongson/include/mach/debug_ll_loongson1.h b/arch/mips/mach-loongson/include/mach/debug_ll_loongson1.h
new file mode 100644
index 0000000..6043690
--- /dev/null
+++ b/arch/mips/mach-loongson/include/mach/debug_ll_loongson1.h
@@ -0,0 +1,15 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+/*
+ * Copyright (C) 2020 Du Huanpeng <u74147@gmail.com>
+ */
+
+#ifndef __INCLUDE_DEBUG_LL_LOONGSON1_H__
+#define __INCLUDE_DEBUG_LL_LOONGSON1_H__
+
+#include <mach/loongson1.h>
+
+#define DEBUG_LL_UART_ADDR 0xBFE48000
+#define DEBUG_LL_UART_SHIFT 0
+#define DEBUG_LL_UART_DIVISOR 0
+
+#endif /* __INCLUDE_DEBUG_LL_LOONGSON1_H__ */
diff --git a/arch/mips/mach-loongson/include/mach/pbl_ll_init_loongson1.h b/arch/mips/mach-loongson/include/mach/pbl_ll_init_loongson1.h
new file mode 100644
index 0000000..e0cca5c
--- /dev/null
+++ b/arch/mips/mach-loongson/include/mach/pbl_ll_init_loongson1.h
@@ -0,0 +1,162 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Copyright (C) 2020 Du Huanpeng <u74147@gmail.com>
+ */
+
+#ifndef __ASM_MACH_LOONGSON1_PBL_LL_INIT_LOONGSON1_H
+#define __ASM_MACH_LOONGSON1_PBL_LL_INIT_LOONGSON1_H
+
+#include <asm/addrspace.h>
+#include <asm/regdef.h>
+
+/*
+ * (12 * 1024 + N) 33 * 625
+ * prescale = ----------------- * ----------
+ * DIV * (baud/25) 1024
+ */
+
+.macro pbl_loongson1_calc_prescale baud
+ .set push
+ .set noreorder
+
+ li a0, \baud
+
+ /* PLL_FREQ -> t8 */
+ li t8, 0xbfe78030
+ lw t8, 0 (t8)
+
+ /* N -> t9, t8 -> X */
+ sra t9, t8, 8
+ andi t9, 0x3f
+ sll t8, 10
+ andi t9, 0x3ff
+ or t9, t8
+
+ /* t9 += 12 * 1024 */
+ li t8, 12288
+ add t9, t8
+ /* DIV -> t8 */
+ li t8, 0xbfe78030
+ lw t8, 4 (t8)
+ sra t8, 14
+ andi t8, 0xf
+
+ multu t8, a0
+ mflo t8
+ li v0, 25
+ divu t8, v0
+ /* t9 = a / b */
+ divu t9, t8
+ mflo t9
+
+ li t8, 20955 /* 33 * 625 */
+ multu t9, t8
+ mflo t9
+
+ sra v0, t9, 10
+
+ .set pop
+.endm
+
+.macro __pbl_loongson1_ddr2_init
+ .set push
+ .set noreorder
+
+ pbl_reg_writel 0x00000101, 0xAFFFFE00
+ pbl_reg_writel 0x01000100, 0xAFFFFE04
+ pbl_reg_writel 0x00000000, 0xAFFFFE10
+ pbl_reg_writel 0x01000000, 0xAFFFFE14
+ pbl_reg_writel 0x00000000, 0xAFFFFE20
+ pbl_reg_writel 0x01000101, 0xAFFFFE24
+ pbl_reg_writel 0x01000100, 0xAFFFFE30
+ pbl_reg_writel 0x01010000, 0xAFFFFE34
+ pbl_reg_writel 0x01010101, 0xAFFFFE40
+ pbl_reg_writel 0x01000202, 0xAFFFFE44
+ pbl_reg_writel 0x04030201, 0xAFFFFE50
+ pbl_reg_writel 0x07000000, 0xAFFFFE54
+ pbl_reg_writel 0x02020203, 0xAFFFFE60
+ pbl_reg_writel 0x0a020203, 0xAFFFFE64
+ pbl_reg_writel 0x00010506, 0xAFFFFE70
+ pbl_reg_writel 0x00000400, 0xAFFFFE74
+ pbl_reg_writel 0x08040201, 0xAFFFFE80
+ pbl_reg_writel 0x08040201, 0xAFFFFE84
+ pbl_reg_writel 0x00000000, 0xAFFFFE90
+ pbl_reg_writel 0x00000306, 0xAFFFFE94
+ pbl_reg_writel 0x3f0b020a, 0xAFFFFEA0
+ pbl_reg_writel 0x0000003f, 0xAFFFFEA4
+ pbl_reg_writel 0x00000000, 0xAFFFFEB0
+ pbl_reg_writel 0x37570000, 0xAFFFFEB4
+ pbl_reg_writel 0x08000000, 0xAFFFFEC0
+ pbl_reg_writel 0x002a1503, 0xAFFFFEC4
+ pbl_reg_writel 0x002a002a, 0xAFFFFED0
+ pbl_reg_writel 0x002a002a, 0xAFFFFED4
+ pbl_reg_writel 0x002a002a, 0xAFFFFEE0
+ pbl_reg_writel 0x002a002a, 0xAFFFFEE4
+ pbl_reg_writel 0x00000002, 0xAFFFFEF0
+ pbl_reg_writel 0x00b40020, 0xAFFFFEF4
+ pbl_reg_writel 0x00000087, 0xAFFFFF00
+ pbl_reg_writel 0x000007ff, 0xAFFFFF04
+ pbl_reg_writel 0x44240618, 0xAFFFFF10
+ pbl_reg_writel 0x80808080, 0xAFFFFF14
+ pbl_reg_writel 0x80808080, 0xAFFFFF20
+ pbl_reg_writel 0x001c8080, 0xAFFFFF24
+ pbl_reg_writel 0x00c8006b, 0xAFFFFF30
+ pbl_reg_writel 0x36b00002, 0xAFFFFF34
+ pbl_reg_writel 0x00c80017, 0xAFFFFF40
+ pbl_reg_writel 0x00000000, 0xAFFFFF44
+ pbl_reg_writel 0x00009c40, 0xAFFFFF50
+ pbl_reg_writel 0x00000000, 0xAFFFFF54
+ pbl_reg_writel 0x00000000, 0xAFFFFF60
+ pbl_reg_writel 0x00000000, 0xAFFFFF64
+ pbl_reg_writel 0x00000000, 0xAFFFFF70
+ pbl_reg_writel 0x00000000, 0xAFFFFF74
+ pbl_reg_writel 0x00000000, 0xAFFFFF80
+ pbl_reg_writel 0x00000000, 0xAFFFFF84
+ pbl_reg_writel 0x00000000, 0xAFFFFF90
+ pbl_reg_writel 0x00000000, 0xAFFFFF94
+ pbl_reg_writel 0x00000000, 0xAFFFFFA0
+ pbl_reg_writel 0x00000000, 0xAFFFFFA4
+ pbl_reg_writel 0x00000000, 0xAFFFFFB0
+ pbl_reg_writel 0x00000000, 0xAFFFFFB4
+ pbl_reg_writel 0x00000000, 0xAFFFFFC0
+ pbl_reg_writel 0x00000000, 0xAFFFFFC4
+
+ .set pop
+.endm
+
+.macro pbl_loongson1_ddr2_init
+ .set push
+ .set noreorder
+
+ /* initial ddr2 controller */
+ pbl_reg_writel 0xfc000000, 0xbfd010c8
+ pbl_reg_writel 0x14000000, 0xbfd010f8
+
+ __pbl_loongson1_ddr2_init
+10:
+ pbl_reg_writel 0x01010100, 0xaffffe34
+
+9: /* not_locked */
+ li t0, 0xaffffe00
+ lw t1, 0x10 (t0)
+ andi t1, t1, 1
+ beqz t1, 9b
+ nop
+
+ lh t1, 0xf2 (t0)
+ sltiu t1, t1, 5
+ beqz t1, 1f
+ nop
+
+ lw t1, 0xf4 (t0)
+ addiu t1, t1, 4
+ sw t1, 0xf4 (t0)
+ b 10b
+ nop
+1:
+ /* 16bit ddr and disable conf */
+ pbl_reg_set 0x110000, 0xbfd00424
+ .set pop
+.endm
+
+#endif /* __ASM_MACH_LOONGSON1_PBL_LL_INIT_LOONGSON1_H */
diff --git a/arch/mips/mach-loongson/include/mach/pbl_macros.h b/arch/mips/mach-loongson/include/mach/pbl_macros.h
new file mode 100644
index 0000000..93402d1
--- /dev/null
+++ b/arch/mips/mach-loongson/include/mach/pbl_macros.h
@@ -0,0 +1,81 @@
+#ifndef __ASM_MACH_LOONGSON1_PBL_MACROS_H
+#define __ASM_MACH_LOONGSON1_PBL_MACROS_H
+
+#include <asm/addrspace.h>
+#include <asm/regdef.h>
+#include <mach/loongson1.h>
+
+#define PLL_FREQ 0xBFE78030
+#define PLL_DIV_PARAM 0xBFE78034
+
+#define CONFIG_CPU_DIV 3
+#define CONFIG_DDR_DIV 4
+#define CONFIG_DC_DIV 4
+#define CONFIG_PLL_FREQ 0x1C
+#define CONFIG_PLL_DIV_PARAM 0x92392a00
+
+.macro pbl_loongson1_pll
+ .set push
+ .set noreorder
+
+ pbl_reg_writel 0x92392a00, PLL_DIV_PARAM
+ pbl_reg_writel 0x0000001c, PLL_FREQ
+ pbl_sleep t8, 40
+
+ .set pop
+.endm
+
+.macro set_cpu_window id, base, mask, mmap
+ .set push
+ .set noreorder
+
+ li t8, 0xbfd00000
+ sw $0, 0x80 + \id * 8 (t8)
+ li t9, \base
+ sw t9, 0x00 + \id * 8 (t8)
+ sw $0, 0x04 + \id * 8 (t8)
+ li t9, \mask
+ sw t9, 0x40 + \id * 8 (t8)
+ sw $0, 0x44 + \id * 8 (t8)
+ li t9, \mmap
+ sw t9, 0x80 + \id * 8 (t8)
+ sw $0, 0x84 + \id * 8 (t8)
+
+ .set pop
+.endm
+
+.macro pbl_loongson1_remap
+ .set push
+
+ set_cpu_window 0, 0x1c300000, 0xfff00000, 0x1c3000d2
+ set_cpu_window 1, 0x1fe10000, 0xffffe000, 0x1fe100d3
+ set_cpu_window 2, 0x1fe20000, 0xffffe000, 0x1fe200d3
+ set_cpu_window 3, 0x1fe10000, 0xffff0000, 0x1fe100d0
+ set_cpu_window 4, 0x1fe20000, 0xffff0000, 0x1fe200d0
+ set_cpu_window 5, 0x1ff00000, 0xfff00000, 0x1ff000d0
+ set_cpu_window 6, 0x1f000000, 0xff000000, 0x1f0000d3
+ set_cpu_window 7, 0x00000000, 0x00000000, 0x000000f0
+ li t8, 0xbfd000e0
+ lw t9, 0x0 (t8)
+ and t9, t9, 0xffffff00
+ ori t9, t9, 0xd0
+ sw t9, 0x0 (t8)
+
+ lw t9, 0x8 (t8)
+ and t9, t9, 0xffffff00
+ ori t9, t9, 0xd0
+ sw t9, 0x8 (t8)
+
+ .set pop
+.endm
+
+#define GPIOCFG1 0xbfd010C4
+.macro pbl_loongson1_uart_enable
+ .set push
+
+ pbl_reg_clr 0x00C00000, GPIOCFG1
+
+ .set pop
+.endm
+
+#endif /* __ASM_MACH_LOONGSON1_PBL_MACROS_H */
--
2.7.4
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^ permalink raw reply [flat|nested] 7+ messages in thread
* [PATCH] MIPS: DEBUG_LL_UART_DIVISOR is 0, use a0 instead
2020-09-11 12:33 [PATCH] MIPS: loongson1: enable to run from spi flash Du Huanpeng
@ 2020-09-11 12:33 ` Du Huanpeng
2020-09-11 14:07 ` Ahmad Fatoum
0 siblings, 1 reply; 7+ messages in thread
From: Du Huanpeng @ 2020-09-11 12:33 UTC (permalink / raw)
To: barebox; +Cc: Du Huanpeng
this make it possiable pass a0 as divisor to calculate uart baudrate
in run time on boot.
Signed-off-by: Du Huanpeng <u74147@gmail.com>
---
arch/mips/include/asm/debug_ll_ns16550.h | 3 +++
1 file changed, 3 insertions(+)
diff --git a/arch/mips/include/asm/debug_ll_ns16550.h b/arch/mips/include/asm/debug_ll_ns16550.h
index df58c4c..a33587a 100644
--- a/arch/mips/include/asm/debug_ll_ns16550.h
+++ b/arch/mips/include/asm/debug_ll_ns16550.h
@@ -66,6 +66,9 @@ static inline void PUTC_LL(char ch)
sb t1, UART_LCR(t0) /* Write it out */
li t1, DEBUG_LL_UART_DIVISOR
+#if DEBUG_LL_UART_DIVISOR == 0
+ move t1, a0
+#endif
sb t1, UART_DLL(t0) /* write low order byte */
srl t1, t1, 8
sb t1, UART_DLM(t0) /* write high order byte */
--
2.7.4
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] MIPS: DEBUG_LL_UART_DIVISOR is 0, use a0 instead
2020-09-11 12:33 ` [PATCH] MIPS: DEBUG_LL_UART_DIVISOR is 0, use a0 instead Du Huanpeng
@ 2020-09-11 14:07 ` Ahmad Fatoum
2020-09-17 13:56 ` Du Huanpeng
0 siblings, 1 reply; 7+ messages in thread
From: Ahmad Fatoum @ 2020-09-11 14:07 UTC (permalink / raw)
To: Du Huanpeng, barebox
On 9/11/20 2:33 PM, Du Huanpeng wrote:
> this make it possiable pass a0 as divisor to calculate uart baudrate
> in run time on boot.
This is not Ok. Your last commit has your board pass the divisor in a0 now, but other
boards, like the netgear-wg102, don't. Your change might break their UART because the
code there doesn't expect that a0 needs to have a valid value. If you want to do this,
you should migrate all users of this function all at once to supply a valid divisor
(probably `move a0, DEBUG_LL_UART_DIVISOR`).
It's same thing in C. You don't add a new parameter to a function without checking
that all callsites handle this correctly.
>
> Signed-off-by: Du Huanpeng <u74147@gmail.com>
> ---
> arch/mips/include/asm/debug_ll_ns16550.h | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/arch/mips/include/asm/debug_ll_ns16550.h b/arch/mips/include/asm/debug_ll_ns16550.h
> index df58c4c..a33587a 100644
> --- a/arch/mips/include/asm/debug_ll_ns16550.h
> +++ b/arch/mips/include/asm/debug_ll_ns16550.h
> @@ -66,6 +66,9 @@ static inline void PUTC_LL(char ch)
> sb t1, UART_LCR(t0) /* Write it out */
>
> li t1, DEBUG_LL_UART_DIVISOR
> +#if DEBUG_LL_UART_DIVISOR == 0
> + move t1, a0
> +#endif
> sb t1, UART_DLL(t0) /* write low order byte */
> srl t1, t1, 8
> sb t1, UART_DLM(t0) /* write high order byte */
>
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] MIPS: DEBUG_LL_UART_DIVISOR is 0, use a0 instead
2020-09-11 14:07 ` Ahmad Fatoum
@ 2020-09-17 13:56 ` Du Huanpeng
2020-09-17 17:42 ` Ahmad Fatoum
0 siblings, 1 reply; 7+ messages in thread
From: Du Huanpeng @ 2020-09-17 13:56 UTC (permalink / raw)
To: Ahmad Fatoum; +Cc: barebox
Hi, this patch should not intoduce any regression to existing boards,
because:
1. pass divisor by DEBUG_LL_UART_DIVISOR
#define DEBUG_LL_UART_DIVISOR NUMBER
which the ``NUMBER'' is not ``0'' (zero). In this case, this patch
has no effect and this line of code will be removed by preprocessor,
before compile :)
move t1, a0
2. Pass divisor by a0
#define DEBUG_LL_UART_DIVISOR 0
recalculate the divisor is needed when the pll/div setting is changed
outside of barebox. e.g. ejtag. and load barebox and run in ram.
Because 0 maybe an invalid value for a divisor, so I take this value for
a hint to pass a0 as divisor. this will not conflict with other boards
which pass divisor by defining DEBUG_LL_UART_DIVISOR with a valied value.
> you should migrate all users of this function all at once to supply a valid divisor
> (probably `move a0, DEBUG_LL_UART_DIVISOR`).
MIPS use ``li'' load immediate, and move to copy inter registers.
so, maybe change my patch to:
#if DEBUG_LL_UART_DIVISOR
li t1, DEBUG_LL_UART_DIVISOR
#else
move t1, a0
#endif
- - -
or even do a bit tricky:
--- a/arch/mips/include/asm/debug_ll_ns16550.h
+++ b/arch/mips/include/asm/debug_ll_ns16550.h
@@ -65,7 +65,7 @@ static inline void PUTC_LL(char ch)
li t1, UART_LCR_DLAB /* DLAB on */
sb t1, UART_LCR(t0) /* Write it out */
- li t1, DEBUG_LL_UART_DIVISOR
+ add t1, zero, DEBUG_LL_UART_DIVISOR
sb t1, UART_DLL(t0) /* write low order byte */
srl t1, t1, 8
sb t1, UART_DLM(t0) /* write high order byte */
--
2.7.4
this will allow to pass divisor by a number or a register.
add is a pseudo insertion can be compile to addi or add depends
on the DEBUG_LL_UART_DIVISOR is a number or a register.
On Fri, Sep 11, 2020 at 04:07:43PM +0200, Ahmad Fatoum wrote:
> On 9/11/20 2:33 PM, Du Huanpeng wrote:
> > this make it possiable pass a0 as divisor to calculate uart baudrate
> > in run time on boot.
>
> This is not Ok. Your last commit has your board pass the divisor in a0 now, but other
> boards, like the netgear-wg102, don't. Your change might break their UART because the
> code there doesn't expect that a0 needs to have a valid value. If you want to do this,
> you should migrate all users of this function all at once to supply a valid divisor
> (probably `move a0, DEBUG_LL_UART_DIVISOR`).
>
> It's same thing in C. You don't add a new parameter to a function without checking
> that all callsites handle this correctly.
>
> >
> > Signed-off-by: Du Huanpeng <u74147@gmail.com>
> > ---
> > arch/mips/include/asm/debug_ll_ns16550.h | 3 +++
> > 1 file changed, 3 insertions(+)
> >
> > diff --git a/arch/mips/include/asm/debug_ll_ns16550.h b/arch/mips/include/asm/debug_ll_ns16550.h
> > index df58c4c..a33587a 100644
> > --- a/arch/mips/include/asm/debug_ll_ns16550.h
> > +++ b/arch/mips/include/asm/debug_ll_ns16550.h
> > @@ -66,6 +66,9 @@ static inline void PUTC_LL(char ch)
> > sb t1, UART_LCR(t0) /* Write it out */
> >
> > li t1, DEBUG_LL_UART_DIVISOR
> > +#if DEBUG_LL_UART_DIVISOR == 0
> > + move t1, a0
> > +#endif
> > sb t1, UART_DLL(t0) /* write low order byte */
> > srl t1, t1, 8
> > sb t1, UART_DLM(t0) /* write high order byte */
> >
>
> --
> Pengutronix e.K. | |
> Steuerwalder Str. 21 | http://www.pengutronix.de/ |
> 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
> Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
Regards,
duhuanpeng
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^ permalink raw reply [flat|nested] 7+ messages in thread* Re: [PATCH] MIPS: DEBUG_LL_UART_DIVISOR is 0, use a0 instead
2020-09-17 13:56 ` Du Huanpeng
@ 2020-09-17 17:42 ` Ahmad Fatoum
2020-09-25 16:42 ` Du Huanpeng
0 siblings, 1 reply; 7+ messages in thread
From: Ahmad Fatoum @ 2020-09-17 17:42 UTC (permalink / raw)
To: Du Huanpeng; +Cc: barebox
Hello,
On 9/17/20 3:56 PM, Du Huanpeng wrote:
> Hi, this patch should not intoduce any regression to existing boards,
> because:
>
> 1. pass divisor by DEBUG_LL_UART_DIVISOR
>
> #define DEBUG_LL_UART_DIVISOR NUMBER
>
> which the ``NUMBER'' is not ``0'' (zero). In this case, this patch
> has no effect and this line of code will be removed by preprocessor,
> before compile :)
> move t1, a0
>
> 2. Pass divisor by a0
>
> #define DEBUG_LL_UART_DIVISOR 0
>
> recalculate the divisor is needed when the pll/div setting is changed
> outside of barebox. e.g. ejtag. and load barebox and run in ram.
>
> Because 0 maybe an invalid value for a divisor, so I take this value for
> a hint to pass a0 as divisor. this will not conflict with other boards
> which pass divisor by defining DEBUG_LL_UART_DIVISOR with a valied value.
I guess we can agree that
debug_ll_ns16550_init(
#if DEBUG_LL_UART_DIVISOR
int a0
#endif
);
is not the best way to go about it, so why do its equivalent in assembly?
>> you should migrate all users of this function all at once to supply a valid divisor
>> (probably `move a0, DEBUG_LL_UART_DIVISOR`).
>
> MIPS use ``li'' load immediate, and move to copy inter registers.
> so, maybe change my patch to:
>
> #if DEBUG_LL_UART_DIVISOR
> li t1, DEBUG_LL_UART_DIVISOR
> #else
> move t1, a0
> #endif
I'd prefer you keep it as move t1, a0 without an ifdef and move the argument
passing out of debug_ll_ns16550_init.
Cheers
Ahmad
>
> - - -
> or even do a bit tricky:
>
> --- a/arch/mips/include/asm/debug_ll_ns16550.h
> +++ b/arch/mips/include/asm/debug_ll_ns16550.h
> @@ -65,7 +65,7 @@ static inline void PUTC_LL(char ch)
> li t1, UART_LCR_DLAB /* DLAB on */
> sb t1, UART_LCR(t0) /* Write it out */
>
> - li t1, DEBUG_LL_UART_DIVISOR
> + add t1, zero, DEBUG_LL_UART_DIVISOR
> sb t1, UART_DLL(t0) /* write low order byte */
> srl t1, t1, 8
> sb t1, UART_DLM(t0) /* write high order byte */
>
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] MIPS: DEBUG_LL_UART_DIVISOR is 0, use a0 instead
2020-09-17 17:42 ` Ahmad Fatoum
@ 2020-09-25 16:42 ` Du Huanpeng
2020-09-25 17:54 ` Ahmad Fatoum
0 siblings, 1 reply; 7+ messages in thread
From: Du Huanpeng @ 2020-09-25 16:42 UTC (permalink / raw)
To: Ahmad Fatoum; +Cc: barebox
Hi, How about this, I send this for review, if it is ok,
I will send a patch later.
I add a argument to the macro, and set a default parameter.
+.macro debug_ll_ns16550_init divisor=DEBUG_LL_UART_DIVISOR
+ /* three forms for ``call'' the macro */
pass a register name
+ debug_ll_ns16550_init v0
pass a immediate number
+ debug_ll_ns16550_init 888
use this macro as usual before
+ debug_ll_ns16550_init
----8<-----
diff --git a/arch/mips/boards/loongson-ls1b/lowlevel.S b/arch/mips/boards/loongson-ls1b/lowlevel.S
index af6ad54e1..7120d80ef 100644
--- a/arch/mips/boards/loongson-ls1b/lowlevel.S
+++ b/arch/mips/boards/loongson-ls1b/lowlevel.S
@@ -28,8 +28,14 @@ ENTRY_FUNCTION(BOARD_PBL_START)
pbl_loongson1_uart_enable
pbl_loongson1_calc_prescale 115200
- move a0, v0
+
+ /* three forms for ``call'' the macro */
+ debug_ll_ns16550_init v0
+ debug_ll_ns16550_init 888
+ debug_ll_ns16550_init
+
debug_ll_ns16550_init
+
debug_ll_ns16550_outnl
debug_ll_outc '.'
debug_ll_ns16550_outnl
diff --git a/arch/mips/include/asm/debug_ll_ns16550.h b/arch/mips/include/asm/debug_ll_ns16550.h
index a33587a15..44f3d5976 100644
--- a/arch/mips/include/asm/debug_ll_ns16550.h
+++ b/arch/mips/include/asm/debug_ll_ns16550.h
@@ -58,17 +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
-#if DEBUG_LL_UART_DIVISOR == 0
- move t1, a0
-#endif
+ add t1, zero, \divisor
sb t1, UART_DLL(t0) /* write low order byte */
srl t1, t1, 8
sb t1, UART_DLM(t0) /* write high order byte */
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^ permalink raw reply [flat|nested] 7+ messages in thread
* Re: [PATCH] MIPS: DEBUG_LL_UART_DIVISOR is 0, use a0 instead
2020-09-25 16:42 ` Du Huanpeng
@ 2020-09-25 17:54 ` Ahmad Fatoum
0 siblings, 0 replies; 7+ messages in thread
From: Ahmad Fatoum @ 2020-09-25 17:54 UTC (permalink / raw)
To: Du Huanpeng; +Cc: barebox
Hello Du,
On 9/25/20 6:42 PM, Du Huanpeng wrote:
> Hi, How about this, I send this for review, if it is ok,
> I will send a patch later.
>
> I add a argument to the macro, and set a default parameter.
>
> +.macro debug_ll_ns16550_init divisor=DEBUG_LL_UART_DIVISOR
Sounds great! Much less error prone IMO.
>
>
> + /* three forms for ``call'' the macro */
> pass a register name
> + debug_ll_ns16550_init v0
>
> pass a immediate number
> + debug_ll_ns16550_init 888
>
> use this macro as usual before
> + debug_ll_ns16550_init
>
> ----8<-----
>
> diff --git a/arch/mips/boards/loongson-ls1b/lowlevel.S b/arch/mips/boards/loongson-ls1b/lowlevel.S
> index af6ad54e1..7120d80ef 100644
> --- a/arch/mips/boards/loongson-ls1b/lowlevel.S
> +++ b/arch/mips/boards/loongson-ls1b/lowlevel.S
> @@ -28,8 +28,14 @@ ENTRY_FUNCTION(BOARD_PBL_START)
>
> pbl_loongson1_uart_enable
> pbl_loongson1_calc_prescale 115200
> - move a0, v0
> +
> + /* three forms for ``call'' the macro */
> + debug_ll_ns16550_init v0
> + debug_ll_ns16550_init 888
> + debug_ll_ns16550_init
> +
> debug_ll_ns16550_init
> +
> debug_ll_ns16550_outnl
> debug_ll_outc '.'
> debug_ll_ns16550_outnl
> diff --git a/arch/mips/include/asm/debug_ll_ns16550.h b/arch/mips/include/asm/debug_ll_ns16550.h
> index a33587a15..44f3d5976 100644
> --- a/arch/mips/include/asm/debug_ll_ns16550.h
> +++ b/arch/mips/include/asm/debug_ll_ns16550.h
> @@ -58,17 +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
> -#if DEBUG_LL_UART_DIVISOR == 0
> - move t1, a0
> -#endif
> + add t1, zero, \divisor
> sb t1, UART_DLL(t0) /* write low order byte */
> srl t1, t1, 8
> sb t1, UART_DLM(t0) /* write high order byte */
>
--
Pengutronix e.K. | |
Steuerwalder Str. 21 | http://www.pengutronix.de/ |
31137 Hildesheim, Germany | Phone: +49-5121-206917-0 |
Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 |
_______________________________________________
barebox mailing list
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^ permalink raw reply [flat|nested] 7+ messages in thread
end of thread, other threads:[~2020-09-25 17:54 UTC | newest]
Thread overview: 7+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2020-09-11 12:33 [PATCH] MIPS: loongson1: enable to run from spi flash Du Huanpeng
2020-09-11 12:33 ` [PATCH] MIPS: DEBUG_LL_UART_DIVISOR is 0, use a0 instead Du Huanpeng
2020-09-11 14:07 ` Ahmad Fatoum
2020-09-17 13:56 ` Du Huanpeng
2020-09-17 17:42 ` Ahmad Fatoum
2020-09-25 16:42 ` Du Huanpeng
2020-09-25 17:54 ` Ahmad Fatoum
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