tty/serial: atmel_serial: auto-enumerate ports

If no platform data provided to enumerate ports, use a bit field
to choose port number and check if port is already initialized.
Use this mechanism for both console and plain serial ports.

Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Acked-by: Grant Likely <grant.likely@secretlab.ca>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 36 insertions, 8 deletions

diff --git a/drivers/tty/serial/atmel_serial.c b/drivers/tty/serial/atmel_serial.c
index bb723542ad24..10743297a001 100644
--- a/drivers/tty/serial/atmel_serial.c
+++ b/drivers/tty/serial/atmel_serial.c
@@ -157,6 +157,7 @@ struct atmel_uart_port {
 };
 
 static struct atmel_uart_port atmel_ports[ATMEL_MAX_UART];
+static unsigned long atmel_ports_in_use;
 
 #ifdef SUPPORT_SYSRQ
 static struct console atmel_console;
@@ -1423,7 +1424,6 @@ static void __devinit atmel_init_port(struct atmel_uart_port *atmel_port,
         port->flags             = UPF_BOOT_AUTOCONF;
         port->ops               = &atmel_pops;
         port->fifosize          = 1;
-        port->line              = pdata->num;
         port->dev               = &pdev->dev;
         port->mapbase   = pdev->resource[0].start;
         port->irq       = pdev->resource[1].start;
@@ -1613,10 +1613,15 @@ static struct console atmel_console = {
 static int __init atmel_console_init(void)
 {
         if (atmel_default_console_device) {
-                add_preferred_console(ATMEL_DEVICENAME,
-                                      atmel_default_console_device->id, NULL);
-                atmel_init_port(&atmel_ports[atmel_default_console_device->id],
-                                atmel_default_console_device);
+                int id = atmel_default_console_device->id;
+                struct atmel_uart_port *port = &atmel_ports[id];
+
+                set_bit(id, &atmel_ports_in_use);
+                port->backup_imr = 0;
+                port->uart.line = id;
+
+                add_preferred_console(ATMEL_DEVICENAME, id, NULL);
+                atmel_init_port(port, atmel_default_console_device);
                 register_console(&atmel_console);
         }
 
@@ -1715,12 +1720,33 @@ static int __devinit atmel_serial_probe(struct platform_device *pdev)
         struct atmel_uart_port *port;
         struct atmel_uart_data *pdata = pdev->dev.platform_data;
         void *data;
-        int ret;
+        int ret = -ENODEV;
 
         BUILD_BUG_ON(ATMEL_SERIAL_RINGSIZE & (ATMEL_SERIAL_RINGSIZE - 1));
 
-        port = &atmel_ports[pdata->num];
+        if (pdata)
+                ret = pdata->num;
+
+        if (ret < 0)
+                /* port id not found in platform data:
+                 * auto-enumerate it */
+                ret = find_first_zero_bit(&atmel_ports_in_use,
+                                sizeof(atmel_ports_in_use));
+
+        if (ret > ATMEL_MAX_UART) {
+                ret = -ENODEV;
+                goto err;
+        }
+
+        if (test_and_set_bit(ret, &atmel_ports_in_use)) {
+                /* port already in use */
+                ret = -EBUSY;
+                goto err;
+        }
+
+        port = &atmel_ports[ret];
         port->backup_imr = 0;
+        port->uart.line = ret;
 
         atmel_init_port(port, pdev);
 
@@ -1766,7 +1792,7 @@ err_alloc_ring:
                 clk_put(port->clk);
                 port->clk = NULL;
         }
-
+err:
         return ret;
 }
 
@@ -1786,6 +1812,8 @@ static int __devexit atmel_serial_remove(struct platform_device *pdev)
 
         /* "port" is allocated statically, so we shouldn't free it */
 
+        clear_bit(port->line, &atmel_ports_in_use);
+
         clk_put(atmel_port->clk);
 
         return ret;