serial: MMIO32 support for 8250_early.c

Provide MMIO32 support in 8250_early (aka earlycon)

[randy.dunlap@oracle.com: fix printk format warnings]
[akpm@linux-foundation.org: fix printk args some more]
Signed-off-by: Samium Gromoff <_deepfire@feelingofgreen.ru>
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 42 insertions, 15 deletions

diff --git a/drivers/serial/8250_early.c b/drivers/serial/8250_early.c
index f279745e9fef..b745792ec25a 100644
--- a/drivers/serial/8250_early.c
+++ b/drivers/serial/8250_early.c
@@ -19,9 +19,11 @@
  * The user can specify the device directly, e.g.,
  *      earlycon=uart8250,io,0x3f8,9600n8
  *      earlycon=uart8250,mmio,0xff5e0000,115200n8
+ *      earlycon=uart8250,mmio32,0xff5e0000,115200n8
  * or
  *      console=uart8250,io,0x3f8,9600n8
  *      console=uart8250,mmio,0xff5e0000,115200n8
+ *      console=uart8250,mmio32,0xff5e0000,115200n8
  */
 
 #include <linux/tty.h>
@@ -48,18 +50,31 @@ static struct early_serial8250_device early_device;
 
 static unsigned int __init serial_in(struct uart_port *port, int offset)
 {
-        if (port->iotype == UPIO_MEM)
+        switch (port->iotype) {
+        case UPIO_MEM:
                 return readb(port->membase + offset);
-        else
+        case UPIO_MEM32:
+                return readl(port->membase + (offset << 2));
+        case UPIO_PORT:
                 return inb(port->iobase + offset);
+        default:
+                return 0;
+        }
 }
 
 static void __init serial_out(struct uart_port *port, int offset, int value)
 {
-        if (port->iotype == UPIO_MEM)
+        switch (port->iotype) {
+        case UPIO_MEM:
                 writeb(value, port->membase + offset);
-        else
+                break;
+        case UPIO_MEM32:
+                writel(value, port->membase + (offset << 2));
+                break;
+        case UPIO_PORT:
                 outb(value, port->iobase + offset);
+                break;
+        }
 }
 
 #define BOTH_EMPTY (UART_LSR_TEMT | UART_LSR_THRE)
@@ -137,15 +152,21 @@ static int __init parse_options(struct early_serial8250_device *device,
                                                                 char *options)
 {
         struct uart_port *port = &device->port;
-        int mmio, length;
+        int mmio, mmio32, length;
 
         if (!options)
                 return -ENODEV;
 
         port->uartclk = BASE_BAUD * 16;
-        if (!strncmp(options, "mmio,", 5)) {
-                port->iotype = UPIO_MEM;
-                port->mapbase = simple_strtoul(options + 5, &options, 0);
+
+        mmio = !strncmp(options, "mmio,", 5);
+        mmio32 = !strncmp(options, "mmio32,", 7);
+        if (mmio || mmio32) {
+                port->iotype = (mmio ? UPIO_MEM : UPIO_MEM32);
+                port->mapbase = simple_strtoul(options + (mmio ? 5 : 7),
+                                               &options, 0);
+                if (mmio32)
+                        port->regshift = 2;
 #ifdef CONFIG_FIX_EARLYCON_MEM
                 set_fixmap_nocache(FIX_EARLYCON_MEM_BASE,
                                         port->mapbase & PAGE_MASK);
@@ -157,11 +178,10 @@ static int __init parse_options(struct early_serial8250_device *device,
                 if (!port->membase) {
                         printk(KERN_ERR "%s: Couldn't ioremap 0x%llx\n",
                                 __func__,
-                               (unsigned long long)port->mapbase);
+                               (unsigned long long) port->mapbase);
                         return -ENOMEM;
                 }
 #endif
-                mmio = 1;
         } else if (!strncmp(options, "io,", 3)) {
                 port->iotype = UPIO_PORT;
                 port->iobase = simple_strtoul(options + 3, &options, 0);
@@ -181,11 +201,18 @@ static int __init parse_options(struct early_serial8250_device *device,
                         device->baud);
         }
 
-        printk(KERN_INFO "Early serial console at %s 0x%llx (options '%s')\n",
-                mmio ? "MMIO" : "I/O port",
-                mmio ? (unsigned long long) port->mapbase
-                     : (unsigned long long) port->iobase,
-                device->options);
+        if (mmio || mmio32)
+                printk(KERN_INFO
+                       "Early serial console at MMIO%s 0x%llu (options '%s')\n",
+                        mmio32 ? "32" : "",
+                        (unsigned long long)port->mapbase,
+                        device->options);
+        else
+                printk(KERN_INFO
+                      "Early serial console at I/O port 0x%lu (options '%s')\n",
+                        port->iobase,
+                        device->options);
+
         return 0;
 }