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>

diff --git a/drivers/tty/serial/earlycon.c b/drivers/tty/serial/earlycon.c
index 64fe25a4285c2d1fe0f13c9ea9c91880fdd40ad9..58d6bcdaf31c9c879824d30402a57987c96ea614 100644 (file)
--- a/drivers/tty/serial/earlycon.c
+++ b/drivers/tty/serial/earlycon.c
@@ -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

diff --git a/drivers/tty/serial/serial_core.c b/drivers/tty/serial/serial_core.c
index 63d29473c703ddfeedce7b24137fe234981f01ff..8379e3fa01625d14ae69f63053d0da26d53b3276 100644 (file)
--- a/drivers/tty/serial/serial_core.c
+++ b/drivers/tty/serial/serial_core.c
@@ -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

diff --git a/include/linux/serial_core.h b/include/linux/serial_core.h
index baf3e1d08416faaf34edd51bca72c2801e7e7e06..cc5c506f07dd3ccb21a53076000a36fb38243ae3 100644 (file)
--- a/include/linux/serial_core.h
+++ b/include/linux/serial_core.h
@@ -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,