serial: 8250_of: Add IO space support

Currently the 8250_of driver only supports MEM IO type
accesses.

Some development boards (Huawei D03, specifically) require
IO space access for 8250-compatible OF driver support, so
add it.

The modification is quite simple: just set the port iotype
and associated flags depending on the device address
resource type.

Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 35 insertions, 27 deletions

diff --git a/drivers/tty/serial/8250/8250_of.c b/drivers/tty/serial/8250/8250_of.c
index 3de8d6a41246..bfb37f0be22f 100644
--- a/drivers/tty/serial/8250/8250_of.c
+++ b/drivers/tty/serial/8250/8250_of.c
@@ -92,13 +92,43 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
                 goto err_unprepare;
         }
 
+        port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_FIXED_PORT |
+                                  UPF_FIXED_TYPE;
         spin_lock_init(&port->lock);
-        port->mapbase = resource.start;
-        port->mapsize = resource_size(&resource);
 
-        /* Check for shifted address mapping */
-        if (of_property_read_u32(np, "reg-offset", &prop) == 0)
-                port->mapbase += prop;
+        if (resource_type(&resource) == IORESOURCE_IO) {
+                port->iotype = UPIO_PORT;
+                port->iobase = resource.start;
+        } else {
+                port->mapbase = resource.start;
+                port->mapsize = resource_size(&resource);
+
+                /* Check for shifted address mapping */
+                if (of_property_read_u32(np, "reg-offset", &prop) == 0)
+                        port->mapbase += prop;
+
+                port->iotype = UPIO_MEM;
+                if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
+                        switch (prop) {
+                        case 1:
+                                port->iotype = UPIO_MEM;
+                                break;
+                        case 2:
+                                port->iotype = UPIO_MEM16;
+                                break;
+                        case 4:
+                                port->iotype = of_device_is_big_endian(np) ?
+                                               UPIO_MEM32BE : UPIO_MEM32;
+                                break;
+                        default:
+                                dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
+                                         prop);
+                                ret = -EINVAL;
+                                goto err_dispose;
+                        }
+                }
+                port->flags |= UPF_IOREMAP;
+        }
 
         /* Check for registers offset within the devices address range */
         if (of_property_read_u32(np, "reg-shift", &prop) == 0)
@@ -114,26 +144,6 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
                 port->line = ret;
 
         port->irq = irq_of_parse_and_map(np, 0);
-        port->iotype = UPIO_MEM;
-        if (of_property_read_u32(np, "reg-io-width", &prop) == 0) {
-                switch (prop) {
-                case 1:
-                        port->iotype = UPIO_MEM;
-                        break;
-                case 2:
-                        port->iotype = UPIO_MEM16;
-                        break;
-                case 4:
-                        port->iotype = of_device_is_big_endian(np) ?
-                                       UPIO_MEM32BE : UPIO_MEM32;
-                        break;
-                default:
-                        dev_warn(&ofdev->dev, "unsupported reg-io-width (%d)\n",
-                                 prop);
-                        ret = -EINVAL;
-                        goto err_dispose;
-                }
-        }
 
         info->rst = devm_reset_control_get_optional_shared(&ofdev->dev, NULL);
         if (IS_ERR(info->rst)) {
@@ -147,8 +157,6 @@ static int of_platform_serial_setup(struct platform_device *ofdev,
 
         port->type = type;
         port->uartclk = clk;
-        port->flags = UPF_SHARE_IRQ | UPF_BOOT_AUTOCONF | UPF_IOREMAP
-                | UPF_FIXED_PORT | UPF_FIXED_TYPE;
         port->irqflags |= IRQF_SHARED;
 
         if (of_property_read_bool(np, "no-loopback-test"))