]> bbs.cooldavid.org Git - net-next-2.6.git/blobdiff - drivers/serial/8250_early.c
serial: convert early_uart to earlycon for 8250
[net-next-2.6.git] / drivers / serial / 8250_early.c
index 7e511199b4c5c91f09fcde69ced030c7ca15043d..947c20507e1f2a4bee47d64d918e9b3ecb167c45 100644 (file)
  * we locate the device directly by its MMIO or I/O port address.
  *
  * The user can specify the device directly, e.g.,
- *     console=uart,io,0x3f8,9600n8
- *     console=uart,mmio,0xff5e0000,115200n8
- * or platform code can call early_uart_console_init() to set
- * the early UART device.
- *
- * After the normal serial driver starts, we try to locate the
- * matching ttyS device and start a console there.
+ *     earlycon=uart8250,io,0x3f8,9600n8
+ *     earlycon=uart8250,mmio,0xff5e0000,115200n8
+ * or
+ *     console=uart8250,io,0x3f8,9600n8
+ *     console=uart8250,mmio,0xff5e0000,115200n8
  */
 
 #include <linux/tty.h>
 #include <linux/serial_core.h>
 #include <linux/serial_reg.h>
 #include <linux/serial.h>
+#include <linux/serial_8250.h>
 #include <asm/io.h>
 #include <asm/serial.h>
+#ifdef CONFIG_FIX_EARLYCON_MEM
+#include <asm/pgtable.h>
+#include <asm/fixmap.h>
+#endif
 
-struct early_uart_device {
+struct early_serial8250_device {
        struct uart_port port;
        char options[16];               /* e.g., 115200n8 */
        unsigned int baud;
 };
 
-static struct early_uart_device early_device __initdata;
-static int early_uart_registered __initdata;
+static struct early_serial8250_device early_device;
 
 static unsigned int __init serial_in(struct uart_port *port, int offset)
 {
@@ -80,7 +82,7 @@ static void __init putc(struct uart_port *port, int c)
        serial_out(port, UART_TX, c);
 }
 
-static void __init early_uart_write(struct console *console, const char *s, unsigned int count)
+static void __init early_serial8250_write(struct console *console, const char *s, unsigned int count)
 {
        struct uart_port *port = &early_device.port;
        unsigned int ier;
@@ -111,7 +113,7 @@ static unsigned int __init probe_baud(struct uart_port *port)
        return (port->uartclk / 16) / quot;
 }
 
-static void __init init_port(struct early_uart_device *device)
+static void __init init_port(struct early_serial8250_device *device)
 {
        struct uart_port *port = &device->port;
        unsigned int divisor;
@@ -130,10 +132,9 @@ static void __init init_port(struct early_uart_device *device)
        serial_out(port, UART_LCR, c & ~UART_LCR_DLAB);
 }
 
-static int __init parse_options(struct early_uart_device *device, char *options)
+static int __init parse_options(struct early_serial8250_device *device, char *options)
 {
        struct uart_port *port = &device->port;
-       int mapsize = 64;
        int mmio, length;
 
        if (!options)
@@ -143,12 +144,18 @@ static int __init parse_options(struct early_uart_device *device, char *options)
        if (!strncmp(options, "mmio,", 5)) {
                port->iotype = UPIO_MEM;
                port->mapbase = simple_strtoul(options + 5, &options, 0);
-               port->membase = ioremap(port->mapbase, mapsize);
+#ifdef CONFIG_FIX_EARLYCON_MEM
+               set_fixmap_nocache(FIX_EARLYCON_MEM_BASE, port->mapbase & PAGE_MASK);
+               port->membase = (void __iomem *)__fix_to_virt(FIX_EARLYCON_MEM_BASE);
+               port->membase += port->mapbase & ~PAGE_MASK;
+#else
+               port->membase = ioremap(port->mapbase, 64);
                if (!port->membase) {
                        printk(KERN_ERR "%s: Couldn't ioremap 0x%lx\n",
                                __FUNCTION__, port->mapbase);
                        return -ENOMEM;
                }
+#endif
                mmio = 1;
        } else if (!strncmp(options, "io,", 3)) {
                port->iotype = UPIO_PORT;
@@ -175,9 +182,16 @@ static int __init parse_options(struct early_uart_device *device, char *options)
        return 0;
 }
 
-static int __init early_uart_setup(struct console *console, char *options)
+static struct console early_serial8250_console __initdata = {
+       .name   = "uart",
+       .write  = early_serial8250_write,
+       .flags  = CON_PRINTBUFFER | CON_BOOT,
+       .index  = -1,
+};
+
+static int __init early_serial8250_setup(char *options)
 {
-       struct early_uart_device *device = &early_device;
+       struct early_serial8250_device *device = &early_device;
        int err;
 
        if (device->port.membase || device->port.iobase)
@@ -190,61 +204,48 @@ static int __init early_uart_setup(struct console *console, char *options)
        return 0;
 }
 
-static struct console early_uart_console __initdata = {
-       .name   = "uart",
-       .write  = early_uart_write,
-       .setup  = early_uart_setup,
-       .flags  = CON_PRINTBUFFER,
-       .index  = -1,
-};
-
-static int __init early_uart_console_init(void)
-{
-       if (!early_uart_registered) {
-               register_console(&early_uart_console);
-               early_uart_registered = 1;
-       }
-       return 0;
-}
-console_initcall(early_uart_console_init);
-
-int __init early_serial_console_init(char *cmdline)
+int __init setup_early_serial8250_console(char *cmdline)
 {
        char *options;
        int err;
 
-       options = strstr(cmdline, "console=uart,");
-       if (!options)
-               return -ENODEV;
+       options = strstr(cmdline, "uart8250,");
+       if (!options) {
+               options = strstr(cmdline, "uart,");
+               if (!options)
+                       return 0;
+       }
 
        options = strchr(cmdline, ',') + 1;
-       if ((err = early_uart_setup(NULL, options)) < 0)
+       if ((err = early_serial8250_setup(options)) < 0)
                return err;
-       return early_uart_console_init();
+
+       register_console(&early_serial8250_console);
+
+       return 0;
 }
 
-static int __init early_uart_console_switch(void)
+int __init serial8250_find_port_for_earlycon(void)
 {
-       struct early_uart_device *device = &early_device;
+       struct early_serial8250_device *device = &early_device;
        struct uart_port *port = &device->port;
-       int mmio, line;
+       int line;
+       int ret;
 
-       if (!(early_uart_console.flags & CON_ENABLED))
-               return 0;
+       if (!device->port.membase && !device->port.iobase)
+               return -ENODEV;
 
-       /* Try to start the normal driver on a matching line.  */
-       mmio = (port->iotype == UPIO_MEM);
-       line = serial8250_start_console(port, device->options);
+       line = serial8250_find_port(port);
        if (line < 0)
-               printk("No ttyS device at %s 0x%lx for console\n",
-                       mmio ? "MMIO" : "I/O port",
-                       mmio ? port->mapbase :
-                           (unsigned long) port->iobase);
+               return -ENODEV;
 
-       unregister_console(&early_uart_console);
-       if (mmio)
-               iounmap(port->membase);
+       ret = update_console_cmdline("uart", 8250,
+                            "ttyS", line, device->options);
+       if (ret < 0)
+               ret = update_console_cmdline("uart", 0,
+                                    "ttyS", line, device->options);
 
-       return 0;
+       return ret;
 }
-late_initcall(early_uart_console_switch);
+
+early_param("earlycon", setup_early_serial8250_console);