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>

diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt
index 44f6b19..d529b13 100644 (file)
--- a/Documentation/kernel-parameters.txt
+++ b/Documentation/kernel-parameters.txt
@@ -681,8 +681,11 @@ and is between 256 and 4096 characters. It is defined in the file
        earlycon=       [KNL] Output early console device and options.
                uart[8250],io,<addr>[,options]
                uart[8250],mmio,<addr>[,options]
+               uart[8250],mmio32,<addr>[,options]
                        Start an early, polled-mode console on the 8250/16550
                        UART at the specified I/O port or MMIO address.
+                       MMIO inter-register address stride is either 8bit (mmio)
+                        or 32bit (mmio32).
                        The options are the same as for ttyS, above.
 
        earlyprintk=    [X86,SH,BLACKFIN]

diff --git a/drivers/serial/8250_early.c b/drivers/serial/8250_early.c
index f279745..b745792 100644 (file)
--- 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;
 }