[PATCH v4 1/3] pnp: Add dev_is_pnp() macro

[PATCH v4 1/3] pnp: Add dev_is_pnp() macro

[Guanbing Huang]

From: Guanbing Huang <albanhuang@tencent.com>

Add dev_is_pnp() macro to determine whether the device is a pnp device.

Signed-off-by: Guanbing Huang <albanhuang@tencent.com>
Reviewed-by: Bing Fan <tombinfan@tencent.com>
Tested-by: Linheng Du <dylanlhdu@tencent.com>
---
 include/linux/pnp.h | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/include/linux/pnp.h b/include/linux/pnp.h
index ddbe7c3ca4ce..792921c06594 100644
--- a/include/linux/pnp.h
+++ b/include/linux/pnp.h
@@ -502,6 +502,8 @@ static inline void pnp_unregister_driver(struct pnp_driver *drv) { }
 
 #endif /* CONFIG_PNP */
 
+#define dev_is_pnp(d) ((d)->bus == &pnp_bus_type)
+
 /**
  * module_pnp_driver() - Helper macro for registering a PnP driver
  * @__pnp_driver: pnp_driver struct
-- 
2.17.1

Re: [PATCH v4 1/3] pnp: Add dev_is_pnp() macro

[Andy Shevchenko]

On Wed, Apr 03, 2024 at 03:41:28PM +0800, Guanbing Huang wrote:
> From: Guanbing Huang <albanhuang@tencent.com>
> 
> Add dev_is_pnp() macro to determine whether the device is a pnp device.

PNP

Suggested-by?

-- 
With Best Regards,
Andy Shevchenko

[PATCH v4 2/3] serial: 8250_port: Add support of pnp irq to __uart_read_properties()

[Guanbing Huang]

From: Guanbing Huang <albanhuang@tencent.com>

The function __uart_read_properties doesn't cover pnp devices, so add irq
processing for pnp devices in the branch.

Signed-off-by: Guanbing Huang <albanhuang@tencent.com>
Reviewed-by: Bing Fan <tombinfan@tencent.com>
Tested-by: Linheng Du <dylanlhdu@tencent.com>
---
 drivers/tty/serial/serial_port.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/tty/serial/serial_port.c b/drivers/tty/serial/serial_port.c
index 22b9eeb23e68..6ed072d61b88 100644
--- a/drivers/tty/serial/serial_port.c
+++ b/drivers/tty/serial/serial_port.c
@@ -14,6 +14,7 @@
 #include <linux/property.h>
 #include <linux/serial_core.h>
 #include <linux/spinlock.h>
+#include <linux/pnp.h>
 
 #include "serial_base.h"
 
@@ -221,7 +222,11 @@ static int __uart_read_properties(struct uart_port *port, bool use_defaults)
 
 	if (dev_is_platform(dev))
 		ret = platform_get_irq(to_platform_device(dev), 0);
-	else
+	else if (dev_is_pnp(dev)) {
+		ret = pnp_irq(to_pnp_dev(dev), 0);
+		if (ret < 0)
+			ret = -ENXIO;
+	} else
 		ret = fwnode_irq_get(dev_fwnode(dev), 0);
 	if (ret == -EPROBE_DEFER)
 		return ret;
-- 
2.17.1

Re: [PATCH v4 2/3] serial: 8250_port: Add support of pnp irq to __uart_read_properties()

[Andy Shevchenko]

On Wed, Apr 03, 2024 at 03:41:29PM +0800, Guanbing Huang wrote:
> From: Guanbing Huang <albanhuang@tencent.com>
> 
> The function __uart_read_properties doesn't cover pnp devices, so add irq

__uart_read_properties()

PNP
IRQ

> processing for pnp devices in the branch.

PNP

...

>  #include <linux/property.h>
>  #include <linux/serial_core.h>
>  #include <linux/spinlock.h>
> +#include <linux/pnp.h>

Keep it ordered (in this context it should go before property.h).

-- 
With Best Regards,
Andy Shevchenko

Re: [PATCH v4 2/3] serial: 8250_port: Add support of pnp irq to __uart_read_properties()

[Andy Shevchenko]

On Wed, Apr 03, 2024 at 12:54:19PM +0300, Andy Shevchenko wrote:
> On Wed, Apr 03, 2024 at 03:41:29PM +0800, Guanbing Huang wrote:


One more thing, the Subject should start with "serial: port: ..."
And also should have PNP IRQ (capitalized).

> > The function __uart_read_properties doesn't cover pnp devices, so add irq
> 
> __uart_read_properties()
> 
> PNP
> IRQ
> 
> > processing for pnp devices in the branch.
> 
> PNP
> 
> ...
> 
> >  #include <linux/property.h>
> >  #include <linux/serial_core.h>
> >  #include <linux/spinlock.h>
> > +#include <linux/pnp.h>
> 
> Keep it ordered (in this context it should go before property.h).

-- 
With Best Regards,
Andy Shevchenko

[PATCH v4 3/3] serial: 8250_pnp: Support configurable reg shift property

[Guanbing Huang]

From: Guanbing Huang <albanhuang@tencent.com>

The 16550a serial port based on the ACPI table requires obtaining the
reg-shift attribute. In the ACPI scenario, If the reg-shift property
is not configured like in DTS, the 16550a serial driver cannot read or
write controller registers properly during initialization.

Signed-off-by: Guanbing Huang <albanhuang@tencent.com>
Reviewed-by: Bing Fan <tombinfan@tencent.com>
Tested-by: Linheng Du <dylanlhdu@tencent.com>
---
v3 -> v4: dependent on two pre patches: "pnp: Add dev_is_pnp() macro" and
          "serial: 8250_port: Add support of pnp irq to  __uart_read_properties()",
          the iotype is reserved, the mapsize is initialized, fix the UPF_SHARE_IRQ
	  flag, check for IRQ being absent
v2 -> v3: switch to use uart_read_port_properties(), change "Signed-off-by" to "Reviewed-by" and "Tested-by"
v1 -> v2: change the names after "Signed off by" to the real names

 drivers/tty/serial/8250/8250_pnp.c | 36 ++++++++++++++++++++----------
 1 file changed, 24 insertions(+), 12 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_pnp.c b/drivers/tty/serial/8250/8250_pnp.c
index 1974bbadc975..292cb8e84b37 100644
--- a/drivers/tty/serial/8250/8250_pnp.c
+++ b/drivers/tty/serial/8250/8250_pnp.c
@@ -435,6 +435,7 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 {
 	struct uart_8250_port uart, *port;
 	int ret, line, flags = dev_id->driver_data;
+	unsigned char iotype;
 
 	if (flags & UNKNOWN_DEV) {
 		ret = serial_pnp_guess_board(dev);
@@ -443,25 +444,31 @@ serial_pnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
 	}
 
 	memset(&uart, 0, sizeof(uart));
-	if (pnp_irq_valid(dev, 0))
-		uart.port.irq = pnp_irq(dev, 0);
 	if ((flags & CIR_PORT) && pnp_port_valid(dev, 2)) {
 		uart.port.iobase = pnp_port_start(dev, 2);
-		uart.port.iotype = UPIO_PORT;
+		iotype = UPIO_PORT;
 	} else if (pnp_port_valid(dev, 0)) {
 		uart.port.iobase = pnp_port_start(dev, 0);
-		uart.port.iotype = UPIO_PORT;
+		iotype = UPIO_PORT;
 	} else if (pnp_mem_valid(dev, 0)) {
 		uart.port.mapbase = pnp_mem_start(dev, 0);
-		uart.port.iotype = UPIO_MEM;
+		uart.port.mapsize = pnp_mem_end(dev, 0) - pnp_mem_start(dev, 0);
+		iotype = UPIO_MEM;
 		uart.port.flags = UPF_IOREMAP;
 	} else
 		return -ENODEV;
 
-	dev_dbg(&dev->dev,
-		 "Setup PNP port: port %#lx, mem %#llx, irq %u, type %u\n",
-		 uart.port.iobase, (unsigned long long)uart.port.mapbase,
-		 uart.port.irq, uart.port.iotype);
+	uart.port.uartclk = 1843200;
+	uart.port.dev = &dev->dev;
+
+	ret = uart_read_port_properties(&uart.port);
+	/* no interrupt -> fall back to polling */
+	if (ret == -ENXIO)
+		ret = 0;
+	if (ret)
+		return ret;
+
+	uart.port.iotype = iotype;
 
 	if (flags & CIR_PORT) {
 		uart.port.flags |= UPF_FIXED_PORT | UPF_FIXED_TYPE;
@@ -471,9 +478,14 @@ 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;
-	device_property_read_u32(&dev->dev, "clock-frequency", &uart.port.uartclk);
-	uart.port.dev = &dev->dev;
+	else
+		uart.port.flags &= ~UPF_SHARE_IRQ;
+
+
+	dev_dbg(&dev->dev,
+		 "Setup PNP port: port %#lx, mem %#llx, size %#llx, irq %u, type %u\n",
+		 uart.port.iobase, (unsigned long long)uart.port.mapbase,
+		 (unsigned long long)uart.port.mapsize, uart.port.irq, uart.port.iotype);
 
 	line = serial8250_register_8250_port(&uart);
 	if (line < 0 || (flags & CIR_PORT))
-- 
2.17.1

Re: [PATCH v4 3/3] serial: 8250_pnp: Support configurable reg shift property

[Andy Shevchenko]

On Wed, Apr 03, 2024 at 03:41:30PM +0800, Guanbing Huang wrote:
> From: Guanbing Huang <albanhuang@tencent.com>
> 
> The 16550a serial port based on the ACPI table requires obtaining the
> reg-shift attribute. In the ACPI scenario, If the reg-shift property
> is not configured like in DTS, the 16550a serial driver cannot read or
> write controller registers properly during initialization.

...

>  		uart.port.mapbase = pnp_mem_start(dev, 0);
> +		uart.port.mapsize = pnp_mem_end(dev, 0) - pnp_mem_start(dev, 0);

pnp_mem_len()

...

Add a comment here to explain that

	/*
	 * The previous call may not set iotype correctly when reg-io-width
	 * property is absent and it doesn't support IO port resource.
	 */

> +	uart.port.iotype = iotype;


>  	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;
> -	device_property_read_u32(&dev->dev, "clock-frequency", &uart.port.uartclk);
> -	uart.port.dev = &dev->dev;
> +	else
> +		uart.port.flags &= ~UPF_SHARE_IRQ;

This is not needed, just move

	uart.port.flags |= UPF_SKIP_TEST | UPF_BOOT_AUTOCONF;

to be before uart_read_properties().

-- 
With Best Regards,
Andy Shevchenko