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Commit 1917ac76 authored by Samium Gromoff's avatar Samium Gromoff Committed by Greg Kroah-Hartman
Browse files

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: default avatarSamium Gromoff <_deepfire@feelingofgreen.ru>
Signed-off-by: default avatarRandy Dunlap <randy.dunlap@oracle.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 0ac8382e

Documentation/kernel-parameters.txt

+3 −0
Original line number Diff line number Diff line
@@ -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]

drivers/serial/8250_early.c

+42 −15
Original line number Diff line number Diff line
@@ -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);
@@ -161,7 +182,6 @@ static int __init parse_options(struct early_serial8250_device *device, 
			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,

	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;

}