Messages in this thread | | | Subject | Re: [PATCH] MIPS: Loongson: Add support for serial console | From | Tiezhu Yang <> | Date | Mon, 18 May 2020 09:08:14 +0800 |
| |
On 05/16/2020 07:09 PM, WANG Xuerui wrote: > On 5/16/20 3:03 PM, Tiezhu Yang wrote: > >> After commit 87fcfa7b7fe6 ("MIPS: Loongson64: Add generic dts"), >> there already exists the node and property of Loongson CPU UART0 >> in loongson3-package.dtsi: >> >> cpu_uart0: serial@1fe001e0 { >> compatible = "ns16550a"; >> reg = <0 0x1fe001e0 0x8>; >> clock-frequency = <33000000>; >> interrupt-parent = <&liointc>; >> interrupts = <10 IRQ_TYPE_LEVEL_HIGH>; >> no-loopback-test; >> }; >> >> In order to support for serial console on the Loongson platform, >> add CONFIG_SERIAL_OF_PLATFORM=y to loongson3_defconfig. >> >> With this patch, we can see the following boot message: >> >> [ 1.877745] printk: console [ttyS0] disabled >> [ 1.881979] 1fe001e0.serial: ttyS0 at MMIO 0x1fe001e0 (irq = 16, >> base_baud = 2062500) is a 16550A >> [ 1.890838] printk: console [ttyS0] enabled >> >> And also, we can login normally from the serial console. >> >> Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn> >> --- >> >> Hi Jiaxun, >> >> Thank you very much for your suggestion. >> >> arch/mips/configs/loongson3_defconfig | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/arch/mips/configs/loongson3_defconfig >> b/arch/mips/configs/loongson3_defconfig >> index 6768c16..cd95f08 100644 >> --- a/arch/mips/configs/loongson3_defconfig >> +++ b/arch/mips/configs/loongson3_defconfig >> @@ -217,6 +217,7 @@ CONFIG_SERIAL_8250_EXTENDED=y >> CONFIG_SERIAL_8250_MANY_PORTS=y >> CONFIG_SERIAL_8250_SHARE_IRQ=y >> CONFIG_SERIAL_8250_RSA=y >> +CONFIG_SERIAL_OF_PLATFORM=y >> CONFIG_HW_RANDOM=y >> CONFIG_RAW_DRIVER=m >> CONFIG_I2C_CHARDEV=y > > Hi, > > The patch title is again exaggerating things. This is a defconfig > change, so please refer to `git log` output of `arch/mips/configs` and > use something like "MIPS: Loongson: loongson3_defconfig: enable serial > console" or "MIPS: Loongson: enable serial console in defconfig". The > current title reads as if Loongson kernels never were able to use a > serial console in the past.
Hi Xuerui,
Thanks for your suggestion.
We can not use the serial console without this patch, so I use the current patch subject.
Anyway, let me modify the patch subject to make it more accurate, I think the following is better: "MIPS: Loongson: Enable devicetree based probing for 8250 ports"
drivers/tty/serial/8250/Kconfig: config SERIAL_OF_PLATFORM tristate "Devicetree based probing for 8250 ports"
I will send v2 later.
Thanks, Tiezhu Yang
| |