[PATCH v3] serial: 8250_pnp: Support configurable reg shift property

[Guanbing Huang]

From: Guanbing Huang <albanhuang@xxxxxxxxxxx>

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@xxxxxxxxxxx>
Reviewed-by: Bing Fan <tombinfan@xxxxxxxxxxx>
Tested-by: Linheng Du <dylanlhdu@xxxxxxxxxxx>
---
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 | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/drivers/tty/serial/8250/8250_pnp.c b/drivers/tty/serial/8250/8250_pnp.c
index 1974bbadc975..aafddede783a 100644
--- a/drivers/tty/serial/8250/8250_pnp.c
+++ b/drivers/tty/serial/8250/8250_pnp.c
@@ -443,25 +443,22 @@ 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;
 	} else if (pnp_port_valid(dev, 0)) {
 		uart.port.iobase = pnp_port_start(dev, 0);
-		uart.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.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);
+	if (ret < 0)
+		return ret;
 
 	if (flags & CIR_PORT) {
 		uart.port.flags |= UPF_FIXED_PORT | UPF_FIXED_TYPE;
@@ -469,11 +466,11 @@ 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;
+
+	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);
 
 	line = serial8250_register_8250_port(&uart);
 	if (line < 0 || (flags & CIR_PORT))
-- 
2.17.1