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path: root/drivers/serial/8250_early.c
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Diffstat (limited to 'drivers/serial/8250_early.c')
-rw-r--r--drivers/serial/8250_early.c117
1 files changed, 59 insertions, 58 deletions
diff --git a/drivers/serial/8250_early.c b/drivers/serial/8250_early.c
index 7e511199b4c..947c20507e1 100644
--- a/drivers/serial/8250_early.c
+++ b/drivers/serial/8250_early.c
@@ -17,13 +17,11 @@
* 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>
@@ -32,17 +30,21 @@
#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);
generated by cgit v1.2.3 (git 2.25.1) at 2024-11-21 12:19:02 +0000