1 files changed, 49 insertions, 162 deletions

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 6b26f767768e..ac137b6a1dc1 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -26,13 +26,15 @@
 
 #define CDNS_UART_TTY_NAME	"ttyPS"
 #define CDNS_UART_NAME		"xuartps"
+#define CDNS_UART_MAJOR		0	/* use dynamic node allocation */
+#define CDNS_UART_MINOR		0	/* works best with devtmpfs */
+#define CDNS_UART_NR_PORTS	16
 #define CDNS_UART_FIFO_SIZE	64	/* FIFO size */
 #define CDNS_UART_REGISTER_SPACE	0x1000
 #define TX_TIMEOUT		500000
 
 /* Rx Trigger level */
 static int rx_trigger_level = 56;
-static int uartps_major;
 module_param(rx_trigger_level, uint, 0444);
 MODULE_PARM_DESC(rx_trigger_level, "Rx trigger level, 1-63 bytes");
 
@@ -188,7 +190,6 @@ MODULE_PARM_DESC(rx_timeout, "Rx timeout, 1-255");
  * @pclk:		APB clock
  * @cdns_uart_driver:	Pointer to UART driver
  * @baud:		Current baud rate
- * @id:			Port ID
  * @clk_rate_change_nb:	Notifier block for clock changes
  * @quirks:		Flags for RXBS support.
  */
@@ -198,7 +199,6 @@ struct cdns_uart {
 	struct clk		*pclk;
 	struct uart_driver	*cdns_uart_driver;
 	unsigned int		baud;
-	int			id;
 	struct notifier_block	clk_rate_change_nb;
 	u32			quirks;
 	bool cts_override;
@@ -1133,6 +1133,8 @@ static const struct uart_ops cdns_uart_ops = {
 #endif
 };
 
+static struct uart_driver cdns_uart_uart_driver;
+
 #ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
 /**
  * cdns_uart_console_putchar - write the character to the FIFO buffer
@@ -1272,6 +1274,16 @@ static int cdns_uart_console_setup(struct console *co, char *options)
 
 	return uart_set_options(port, co, baud, parity, bits, flow);
 }
+
+static struct console cdns_uart_console = {
+	.name	= CDNS_UART_TTY_NAME,
+	.write	= cdns_uart_console_write,
+	.device	= uart_console_device,
+	.setup	= cdns_uart_console_setup,
+	.flags	= CON_PRINTBUFFER,
+	.index	= -1, /* Specified on the cmdline (e.g. console=ttyPS ) */
+	.data	= &cdns_uart_uart_driver,
+};
 #endif /* CONFIG_SERIAL_XILINX_PS_UART_CONSOLE */
 
 #ifdef CONFIG_PM_SLEEP
@@ -1403,89 +1415,8 @@ static const struct of_device_id cdns_uart_of_match[] = {
 };
 MODULE_DEVICE_TABLE(of, cdns_uart_of_match);
 
-/*
- * Maximum number of instances without alias IDs but if there is alias
- * which target "< MAX_UART_INSTANCES" range this ID can't be used.
- */
-#define MAX_UART_INSTANCES	32
-
-/* Stores static aliases list */
-static DECLARE_BITMAP(alias_bitmap, MAX_UART_INSTANCES);
-static int alias_bitmap_initialized;
-
-/* Stores actual bitmap of allocated IDs with alias IDs together */
-static DECLARE_BITMAP(bitmap, MAX_UART_INSTANCES);
-/* Protect bitmap operations to have unique IDs */
-static DEFINE_MUTEX(bitmap_lock);
-
-static int cdns_get_id(struct platform_device *pdev)
-{
-	int id, ret;
-
-	mutex_lock(&bitmap_lock);
-
-	/* Alias list is stable that's why get alias bitmap only once */
-	if (!alias_bitmap_initialized) {
-		ret = of_alias_get_alias_list(cdns_uart_of_match, "serial",
-					      alias_bitmap, MAX_UART_INSTANCES);
-		if (ret && ret != -EOVERFLOW) {
-			mutex_unlock(&bitmap_lock);
-			return ret;
-		}
-
-		alias_bitmap_initialized++;
-	}
-
-	/* Make sure that alias ID is not taken by instance without alias */
-	bitmap_or(bitmap, bitmap, alias_bitmap, MAX_UART_INSTANCES);
-
-	dev_dbg(&pdev->dev, "Alias bitmap: %*pb\n",
-		MAX_UART_INSTANCES, bitmap);
-
-	/* Look for a serialN alias */
-	id = of_alias_get_id(pdev->dev.of_node, "serial");
-	if (id < 0) {
-		dev_warn(&pdev->dev,
-			 "No serial alias passed. Using the first free id\n");
-
-		/*
-		 * Start with id 0 and check if there is no serial0 alias
-		 * which points to device which is compatible with this driver.
-		 * If alias exists then try next free position.
-		 */
-		id = 0;
-
-		for (;;) {
-			dev_info(&pdev->dev, "Checking id %d\n", id);
-			id = find_next_zero_bit(bitmap, MAX_UART_INSTANCES, id);
-
-			/* No free empty instance */
-			if (id == MAX_UART_INSTANCES) {
-				dev_err(&pdev->dev, "No free ID\n");
-				mutex_unlock(&bitmap_lock);
-				return -EINVAL;
-			}
-
-			dev_dbg(&pdev->dev, "The empty id is %d\n", id);
-			/* Check if ID is empty */
-			if (!test_and_set_bit(id, bitmap)) {
-				/* Break the loop if bit is taken */
-				dev_dbg(&pdev->dev,
-					"Selected ID %d allocation passed\n",
-					id);
-				break;
-			}
-			dev_dbg(&pdev->dev,
-				"Selected ID %d allocation failed\n", id);
-			/* if taking bit fails then try next one */
-			id++;
-		}
-	}
-
-	mutex_unlock(&bitmap_lock);
-
-	return id;
-}
+/* Temporary variable for storing number of instances */
+static int instances;
 
 /**
  * cdns_uart_probe - Platform driver probe
@@ -1495,16 +1426,11 @@ static int cdns_get_id(struct platform_device *pdev)
  */
 static int cdns_uart_probe(struct platform_device *pdev)
 {
-	int rc, irq;
+	int rc, id, irq;
 	struct uart_port *port;
 	struct resource *res;
 	struct cdns_uart *cdns_uart_data;
 	const struct of_device_id *match;
-	struct uart_driver *cdns_uart_uart_driver;
-	char *driver_name;
-#ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
-	struct console *cdns_uart_console;
-#endif
 
 	cdns_uart_data = devm_kzalloc(&pdev->dev, sizeof(*cdns_uart_data),
 			GFP_KERNEL);
@@ -1514,64 +1440,35 @@ static int cdns_uart_probe(struct platform_device *pdev)
 	if (!port)
 		return -ENOMEM;
 
-	cdns_uart_uart_driver = devm_kzalloc(&pdev->dev,
-					     sizeof(*cdns_uart_uart_driver),
-					     GFP_KERNEL);
-	if (!cdns_uart_uart_driver)
-		return -ENOMEM;
-
-	cdns_uart_data->id = cdns_get_id(pdev);
-	if (cdns_uart_data->id < 0)
-		return cdns_uart_data->id;
+	/* Look for a serialN alias */
+	id = of_alias_get_id(pdev->dev.of_node, "serial");
+	if (id < 0)
+		id = 0;
 
-	/* There is a need to use unique driver name */
-	driver_name = devm_kasprintf(&pdev->dev, GFP_KERNEL, "%s%d",
-				     CDNS_UART_NAME, cdns_uart_data->id);
-	if (!driver_name) {
-		rc = -ENOMEM;
-		goto err_out_id;
+	if (id >= CDNS_UART_NR_PORTS) {
+		dev_err(&pdev->dev, "Cannot get uart_port structure\n");
+		return -ENODEV;
 	}
 
-	cdns_uart_uart_driver->owner = THIS_MODULE;
-	cdns_uart_uart_driver->driver_name = driver_name;
-	cdns_uart_uart_driver->dev_name	= CDNS_UART_TTY_NAME;
-	cdns_uart_uart_driver->major = uartps_major;
-	cdns_uart_uart_driver->minor = cdns_uart_data->id;
-	cdns_uart_uart_driver->nr = 1;
-
+	if (!cdns_uart_uart_driver.state) {
+		cdns_uart_uart_driver.owner = THIS_MODULE;
+		cdns_uart_uart_driver.driver_name = CDNS_UART_NAME;
+		cdns_uart_uart_driver.dev_name = CDNS_UART_TTY_NAME;
+		cdns_uart_uart_driver.major = CDNS_UART_MAJOR;
+		cdns_uart_uart_driver.minor = CDNS_UART_MINOR;
+		cdns_uart_uart_driver.nr = CDNS_UART_NR_PORTS;
 #ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
-	cdns_uart_console = devm_kzalloc(&pdev->dev, sizeof(*cdns_uart_console),
-					 GFP_KERNEL);
-	if (!cdns_uart_console) {
-		rc = -ENOMEM;
-		goto err_out_id;
-	}
-
-	strncpy(cdns_uart_console->name, CDNS_UART_TTY_NAME,
-		sizeof(cdns_uart_console->name));
-	cdns_uart_console->index = cdns_uart_data->id;
-	cdns_uart_console->write = cdns_uart_console_write;
-	cdns_uart_console->device = uart_console_device;
-	cdns_uart_console->setup = cdns_uart_console_setup;
-	cdns_uart_console->flags = CON_PRINTBUFFER;
-	cdns_uart_console->data = cdns_uart_uart_driver;
-	cdns_uart_uart_driver->cons = cdns_uart_console;
+		cdns_uart_uart_driver.cons = &cdns_uart_console;
 #endif
 
-	rc = uart_register_driver(cdns_uart_uart_driver);
-	if (rc < 0) {
-		dev_err(&pdev->dev, "Failed to register driver\n");
-		goto err_out_id;
+		rc = uart_register_driver(&cdns_uart_uart_driver);
+		if (rc < 0) {
+			dev_err(&pdev->dev, "Failed to register driver\n");
+			return rc;
+		}
 	}
 
-	cdns_uart_data->cdns_uart_driver = cdns_uart_uart_driver;
-
-	/*
-	 * Setting up proper name_base needs to be done after uart
-	 * registration because tty_driver structure is not filled.
-	 * name_base is 0 by default.
-	 */
-	cdns_uart_uart_driver->tty_driver->name_base = cdns_uart_data->id;
+	cdns_uart_data->cdns_uart_driver = &cdns_uart_uart_driver;
 
 	match = of_match_node(cdns_uart_of_match, pdev->dev.of_node);
 	if (match && match->data) {
@@ -1649,6 +1546,7 @@ static int cdns_uart_probe(struct platform_device *pdev)
 	port->ops	= &cdns_uart_ops;
 	port->fifosize	= CDNS_UART_FIFO_SIZE;
 	port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_XILINX_PS_UART_CONSOLE);
+	port->line	= id;
 
 	/*
 	 * Register the port.
@@ -1680,7 +1578,7 @@ static int cdns_uart_probe(struct platform_device *pdev)
 		console_port = port;
 #endif
 
-	rc = uart_add_one_port(cdns_uart_uart_driver, port);
+	rc = uart_add_one_port(&cdns_uart_uart_driver, port);
 	if (rc) {
 		dev_err(&pdev->dev,
 			"uart_add_one_port() failed; err=%i\n", rc);
@@ -1690,13 +1588,15 @@ static int cdns_uart_probe(struct platform_device *pdev)
 #ifdef CONFIG_SERIAL_XILINX_PS_UART_CONSOLE
 	/* This is not port which is used for console that's why clean it up */
 	if (console_port == port &&
-	    !(cdns_uart_uart_driver->cons->flags & CON_ENABLED))
+	    !(cdns_uart_uart_driver.cons->flags & CON_ENABLED))
 		console_port = NULL;
 #endif
 
-	uartps_major = cdns_uart_uart_driver->tty_driver->major;
 	cdns_uart_data->cts_override = of_property_read_bool(pdev->dev.of_node,
 							     "cts-override");
+
+	instances++;
+
 	return 0;
 
 err_out_pm_disable:
@@ -1712,12 +1612,8 @@ err_out_clk_disable:
 err_out_clk_dis_pclk:
 	clk_disable_unprepare(cdns_uart_data->pclk);
 err_out_unregister_driver:
-	uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
-err_out_id:
-	mutex_lock(&bitmap_lock);
-	if (cdns_uart_data->id < MAX_UART_INSTANCES)
-		clear_bit(cdns_uart_data->id, bitmap);
-	mutex_unlock(&bitmap_lock);
+	if (!instances)
+		uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
 	return rc;
 }
 
@@ -1740,10 +1636,6 @@ static int cdns_uart_remove(struct platform_device *pdev)
 #endif
 	rc = uart_remove_one_port(cdns_uart_data->cdns_uart_driver, port);
 	port->mapbase = 0;
-	mutex_lock(&bitmap_lock);
-	if (cdns_uart_data->id < MAX_UART_INSTANCES)
-		clear_bit(cdns_uart_data->id, bitmap);
-	mutex_unlock(&bitmap_lock);
 	clk_disable_unprepare(cdns_uart_data->uartclk);
 	clk_disable_unprepare(cdns_uart_data->pclk);
 	pm_runtime_disable(&pdev->dev);
@@ -1756,13 +1648,8 @@ static int cdns_uart_remove(struct platform_device *pdev)
 		console_port = NULL;
 #endif
 
-	/* If this is last instance major number should be initialized */
-	mutex_lock(&bitmap_lock);
-	if (bitmap_empty(bitmap, MAX_UART_INSTANCES))
-		uartps_major = 0;
-	mutex_unlock(&bitmap_lock);
-
-	uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
+	if (!--instances)
+		uart_unregister_driver(cdns_uart_data->cdns_uart_driver);
 	return rc;
 }