serial: earlycon: Refactor parse_options into serial core

Prepare to support console-defined matching; refactor the command
line parameter string processing from parse_options() into a
new core function, uart_parse_earlycon(), which decodes command line
parameters of the form:
   earlycon=<name>,io|mmio|mmio32,<addr>,<options>
   console=<name>,io|mmio|mmio32,<addr>,<options>
   earlycon=<name>,0x<addr>,<options>
   console=<name>,0x<addr>,<options>

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Peter Hurley 2015-03-01 11:05:46 -05:00 committed by Greg Kroah-Hartman
parent 1e1257860f
commit 73abaf87f0
3 changed files with 61 additions and 26 deletions

View File

@ -54,44 +54,31 @@ static void __iomem * __init earlycon_map(unsigned long paddr, size_t size)
return base;
}
static int __init parse_options(struct earlycon_device *device,
char *options)
static int __init parse_options(struct earlycon_device *device, char *options)
{
struct uart_port *port = &device->port;
int mmio, mmio32, length;
int length;
unsigned long addr;
if (!options)
return -ENODEV;
if (uart_parse_earlycon(options, &port->iotype, &addr, &options))
return -EINVAL;
mmio = !strncmp(options, "mmio,", 5);
mmio32 = !strncmp(options, "mmio32,", 7);
if (mmio || mmio32) {
port->iotype = (mmio ? UPIO_MEM : UPIO_MEM32);
options += mmio ? 5 : 7;
addr = simple_strtoul(options, NULL, 0);
switch (port->iotype) {
case UPIO_MEM32:
port->regshift = 2; /* fall-through */
case UPIO_MEM:
port->mapbase = addr;
if (mmio32)
port->regshift = 2;
} else if (!strncmp(options, "io,", 3)) {
port->iotype = UPIO_PORT;
options += 3;
addr = simple_strtoul(options, NULL, 0);
break;
case UPIO_PORT:
port->iobase = addr;
mmio = 0;
} else if (!strncmp(options, "0x", 2)) {
port->iotype = UPIO_MEM;
addr = simple_strtoul(options, NULL, 0);
port->mapbase = addr;
} else {
break;
default:
return -EINVAL;
}
port->uartclk = BASE_BAUD * 16;
options = strchr(options, ',');
if (options) {
options++;
device->baud = simple_strtoul(options, NULL, 0);
length = min(strcspn(options, " ") + 1,
(size_t)(sizeof(device->options)));
@ -100,7 +87,7 @@ static int __init parse_options(struct earlycon_device *device,
if (port->iotype == UPIO_MEM || port->iotype == UPIO_MEM32)
pr_info("Early serial console at MMIO%s 0x%llx (options '%s')\n",
mmio32 ? "32" : "",
(port->iotype == UPIO_MEM32) ? "32" : "",
(unsigned long long)port->mapbase,
device->options);
else

View File

@ -1808,6 +1808,52 @@ uart_get_console(struct uart_port *ports, int nr, struct console *co)
return ports + idx;
}
/**
* uart_parse_earlycon - Parse earlycon options
* @p: ptr to 2nd field (ie., just beyond '<name>,')
* @iotype: ptr for decoded iotype (out)
* @addr: ptr for decoded mapbase/iobase (out)
* @options: ptr for <options> field; NULL if not present (out)
*
* Decodes earlycon kernel command line parameters of the form
* earlycon=<name>,io|mmio|mmio32,<addr>,<options>
* console=<name>,io|mmio|mmio32,<addr>,<options>
*
* The optional form
* earlycon=<name>,0x<addr>,<options>
* console=<name>,0x<addr>,<options>
* is also accepted; the returned @iotype will be UPIO_MEM.
*
* Returns 0 on success or -EINVAL on failure
*/
int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
char **options)
{
if (strncmp(p, "mmio,", 5) == 0) {
*iotype = UPIO_MEM;
p += 5;
} else if (strncmp(p, "mmio32,", 7) == 0) {
*iotype = UPIO_MEM32;
p += 7;
} else if (strncmp(p, "io,", 3) == 0) {
*iotype = UPIO_PORT;
p += 3;
} else if (strncmp(p, "0x", 2) == 0) {
*iotype = UPIO_MEM;
} else {
return -EINVAL;
}
*addr = simple_strtoul(p, NULL, 0);
p = strchr(p, ',');
if (p)
p++;
*options = p;
return 0;
}
EXPORT_SYMBOL_GPL(uart_parse_earlycon);
/**
* uart_parse_options - Parse serial port baud/parity/bits/flow control.
* @options: pointer to option string

View File

@ -354,6 +354,8 @@ early_param("earlycon", name ## _setup_earlycon);
struct uart_port *uart_get_console(struct uart_port *ports, int nr,
struct console *c);
int uart_parse_earlycon(char *p, unsigned char *iotype, unsigned long *addr,
char **options);
void uart_parse_options(char *options, int *baud, int *parity, int *bits,
int *flow);
int uart_set_options(struct uart_port *port, struct console *co, int baud,