[PATCH] serial: 8250_pnp: Support configurable clock frequency

[PATCH] serial: 8250_pnp: Support configurable clock frequency

[Huacai Chen]

From: Jianmin Lv <lvjianmin@loongson.cn>

ACPI-based Loongson boards need configurable rather than fixed clock
frequency for serial ports.

Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---
 drivers/tty/serial/8250/8250_pnp.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/8250/8250_pnp.c b/drivers/tty/serial/8250/8250_pnp.c
index de90d681b64c..5f8fc724ba46 100644
--- a/drivers/tty/serial/8250/8250_pnp.c
+++ b/drivers/tty/serial/8250/8250_pnp.c
@@ -15,6 +15,7 @@
 #include <linux/kernel.h>
 #include <linux/serial_core.h>
 #include <linux/bitops.h>
+#include <linux/property.h>
 
 #include <asm/byteorder.h>
 
@@ -474,7 +475,9 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 	uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
 	if (pnp_irq_flags(dev, 0) & IORESOURCE_IRQ_SHAREABLE)
 		uart.port.flags |= UPF_SHARE_IRQ;
-	uart.port.uartclk = 1843200;
+	if (device_property_read_u32(&dev->dev, "clock-frequency", &uart.port.uartclk)) {
+		uart.port.uartclk = 1843200;
+	}
 	uart.port.dev = &dev->dev;
 
 	line = serial8250_register_8250_port(&uart);
-- 
2.27.0

Re: [PATCH] serial: 8250_pnp: Support configurable clock frequency

[Greg Kroah-Hartman]

On Mon, Jul 05, 2021 at 08:12:38PM +0800, Huacai Chen wrote:
> From: Jianmin Lv <lvjianmin@loongson.cn>
> 
> ACPI-based Loongson boards need configurable rather than fixed clock
> frequency for serial ports.
> 
> Signed-off-by: Jianmin Lv <lvjianmin@loongson.cn>
> Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
> ---
>  drivers/tty/serial/8250/8250_pnp.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/tty/serial/8250/8250_pnp.c b/drivers/tty/serial/8250/8250_pnp.c
> index de90d681b64c..5f8fc724ba46 100644
> --- a/drivers/tty/serial/8250/8250_pnp.c
> +++ b/drivers/tty/serial/8250/8250_pnp.c
> @@ -15,6 +15,7 @@
>  #include <linux/kernel.h>
>  #include <linux/serial_core.h>
>  #include <linux/bitops.h>
> +#include <linux/property.h>
>  
>  #include <asm/byteorder.h>
>  
> @@ -474,7 +475,9 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
>  	uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;
>  	if (pnp_irq_flags(dev, 0) & IORESOURCE_IRQ_SHAREABLE)
>  		uart.port.flags |= UPF_SHARE_IRQ;
> -	uart.port.uartclk = 1843200;
> +	if (device_property_read_u32(&dev->dev, "clock-frequency", &uart.port.uartclk)) {
> +		uart.port.uartclk = 1843200;
> +	}
>  	uart.port.dev = &dev->dev;
>  
>  	line = serial8250_register_8250_port(&uart);
> -- 
> 2.27.0
> 

Hi,

This is the friendly patch-bot of Greg Kroah-Hartman.  You have sent him
a patch that has triggered this response.  He used to manually respond
to these common problems, but in order to save his sanity (he kept
writing the same thing over and over, yet to different people), I was
created.  Hopefully you will not take offence and will fix the problem
in your patch and resubmit it so that it can be accepted into the Linux
kernel tree.

You are receiving this message because of the following common error(s)
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- Your patch contains warnings and/or errors noticed by the
  scripts/checkpatch.pl tool.

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thanks,

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