1 files changed, 150 insertions, 230 deletions

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 98db9dc168ff..2eff7cff57c4 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -2,7 +2,7 @@
 /*
  * Cadence UART driver (found in Xilinx Zynq)
  *
- * 2011 - 2014 (C) Xilinx Inc.
+ * Copyright (c) 2011 - 2014 Xilinx, Inc.
  *
  * This driver has originally been pushed by Xilinx using a Zynq-branding. This
  * still shows in the naming of this file, the kconfig symbols and some symbols
@@ -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");
 
@@ -188,9 +190,9 @@ 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.
+ * @cts_override:	Modem control state override
  */
 struct cdns_uart {
 	struct uart_port	*port;
@@ -198,7 +200,6 @@ 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;
@@ -300,9 +301,8 @@ static void cdns_uart_handle_rx(void *dev_id, unsigned int isrstatus)
 		tty_insert_flip_char(&port->state->port, data, status);
 		isrstatus = 0;
 	}
-	spin_unlock(&port->lock);
+
 	tty_flip_buffer_push(&port->state->port);
-	spin_lock(&port->lock);
 }
 
 /**
@@ -313,41 +313,27 @@ static void cdns_uart_handle_rx(void *dev_id, unsigned int isrstatus)
 static void cdns_uart_handle_tx(void *dev_id)
 {
 	struct uart_port *port = (struct uart_port *)dev_id;
+	struct circ_buf *xmit = &port->state->xmit;
 	unsigned int numbytes;
 
-	if (uart_circ_empty(&port->state->xmit)) {
+	if (uart_circ_empty(xmit)) {
 		writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IDR);
-	} else {
-		numbytes = port->fifosize;
-		while (numbytes && !uart_circ_empty(&port->state->xmit) &&
-		       !(readl(port->membase + CDNS_UART_SR) &
-						CDNS_UART_SR_TXFULL)) {
-			/*
-			 * Get the data from the UART circular buffer
-			 * and write it to the cdns_uart's TX_FIFO
-			 * register.
-			 */
-			writel(
-				port->state->xmit.buf[port->state->xmit.tail],
-					port->membase + CDNS_UART_FIFO);
-
-			port->icount.tx++;
-
-			/*
-			 * Adjust the tail of the UART buffer and wrap
-			 * the buffer if it reaches limit.
-			 */
-			port->state->xmit.tail =
-				(port->state->xmit.tail + 1) &
-					(UART_XMIT_SIZE - 1);
-
-			numbytes--;
-		}
+		return;
+	}
 
-		if (uart_circ_chars_pending(
-				&port->state->xmit) < WAKEUP_CHARS)
-			uart_write_wakeup(port);
+	numbytes = port->fifosize;
+	while (numbytes && !uart_circ_empty(xmit) &&
+	       !(readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)) {
+
+		writel(xmit->buf[xmit->tail], port->membase + CDNS_UART_FIFO);
+
+		port->icount.tx++;
+		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
+		numbytes--;
 	}
+
+	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
+		uart_write_wakeup(port);
 }
 
 /**
@@ -375,6 +361,8 @@ static irqreturn_t cdns_uart_isr(int irq, void *dev_id)
 		isrstatus &= ~CDNS_UART_IXR_TXEMPTY;
 	}
 
+	isrstatus &= port->read_status_mask;
+	isrstatus &= ~port->ignore_status_mask;
 	/*
 	 * Skip RX processing if RX is disabled as RXEMPTY will never be set
 	 * as read bytes will not be removed from the FIFO.
@@ -484,7 +472,7 @@ static unsigned int cdns_uart_set_baud_rate(struct uart_port *port,
 
 #ifdef CONFIG_COMMON_CLK
 /**
- * cdns_uart_clk_notitifer_cb - Clock notifier callback
+ * cdns_uart_clk_notifier_cb - Clock notifier callback
  * @nb:		Notifier block
  * @event:	Notify event
  * @data:	Notifier data
@@ -497,8 +485,8 @@ static int cdns_uart_clk_notifier_cb(struct notifier_block *nb,
 	struct uart_port *port;
 	int locked = 0;
 	struct clk_notifier_data *ndata = data;
-	unsigned long flags = 0;
 	struct cdns_uart *cdns_uart = to_cdns_uart(nb);
+	unsigned long flags;
 
 	port = cdns_uart->port;
 	if (port->suspended)
@@ -544,7 +532,7 @@ static int cdns_uart_clk_notifier_cb(struct notifier_block *nb,
 
 		cdns_uart->baud = cdns_uart_set_baud_rate(cdns_uart->port,
 				cdns_uart->baud);
-		/* fall through */
+		fallthrough;
 	case ABORT_RATE_CHANGE:
 		if (!locked)
 			spin_lock_irqsave(&cdns_uart->port->lock, flags);
@@ -601,9 +589,10 @@ static void cdns_uart_start_tx(struct uart_port *port)
 	if (uart_circ_empty(&port->state->xmit))
 		return;
 
+	writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_ISR);
+
 	cdns_uart_handle_tx(port);
 
-	writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_ISR);
 	/* Enable the TX Empty interrupt */
 	writel(CDNS_UART_IXR_TXEMPTY, port->membase + CDNS_UART_IER);
 }
@@ -650,8 +639,8 @@ static unsigned int cdns_uart_tx_empty(struct uart_port *port)
 	unsigned int status;
 
 	status = readl(port->membase + CDNS_UART_SR) &
-				CDNS_UART_SR_TXEMPTY;
-	return status ? TIOCSER_TEMT : 0;
+		       (CDNS_UART_SR_TXEMPTY | CDNS_UART_SR_TACTIVE);
+	return (status == CDNS_UART_SR_TXEMPTY) ? TIOCSER_TEMT : 0;
 }
 
 /**
@@ -688,25 +677,14 @@ static void cdns_uart_break_ctl(struct uart_port *port, int ctl)
  * @old: Values of the previously saved termios structure
  */
 static void cdns_uart_set_termios(struct uart_port *port,
-				struct ktermios *termios, struct ktermios *old)
+				  struct ktermios *termios,
+				  const struct ktermios *old)
 {
 	u32 cval = 0;
 	unsigned int baud, minbaud, maxbaud;
 	unsigned long flags;
-	unsigned int ctrl_reg, mode_reg, val;
-	int err;
-
-	/* Wait for the transmit FIFO to empty before making changes */
-	if (!(readl(port->membase + CDNS_UART_CR) &
-				CDNS_UART_CR_TX_DIS)) {
-		err = readl_poll_timeout(port->membase + CDNS_UART_SR,
-					 val, (val & CDNS_UART_SR_TXEMPTY),
-					 1000, TX_TIMEOUT);
-		if (err) {
-			dev_err(port->dev, "timed out waiting for tx empty");
-			return;
-		}
-	}
+	unsigned int ctrl_reg, mode_reg;
+
 	spin_lock_irqsave(&port->lock, flags);
 
 	/* Disable the TX and RX to set baud rate */
@@ -1145,21 +1123,50 @@ 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
  * @port: Handle to the uart port structure
  * @ch: Character to be written
  */
-static void cdns_uart_console_putchar(struct uart_port *port, int ch)
+static void cdns_uart_console_putchar(struct uart_port *port, unsigned char ch)
 {
-	while (readl(port->membase + CDNS_UART_SR) & CDNS_UART_SR_TXFULL)
+	unsigned int ctrl_reg;
+	unsigned long timeout;
+
+	timeout = jiffies + msecs_to_jiffies(1000);
+	while (1) {
+		ctrl_reg = readl(port->membase + CDNS_UART_CR);
+		if (!(ctrl_reg & CDNS_UART_CR_TX_DIS))
+			break;
+		if (time_after(jiffies, timeout)) {
+			dev_warn(port->dev,
+				 "timeout waiting for Enable\n");
+			return;
+		}
+		cpu_relax();
+	}
+
+	timeout = jiffies + msecs_to_jiffies(1000);
+	while (1) {
+		ctrl_reg = readl(port->membase + CDNS_UART_SR);
+
+		if (!(ctrl_reg & CDNS_UART_SR_TXFULL))
+			break;
+		if (time_after(jiffies, timeout)) {
+			dev_warn(port->dev,
+				 "timeout waiting for TX fifo\n");
+			return;
+		}
 		cpu_relax();
+	}
 	writel(ch, port->membase + CDNS_UART_FIFO);
 }
 
 static void cdns_early_write(struct console *con, const char *s,
-				    unsigned n)
+				    unsigned int n)
 {
 	struct earlycon_device *dev = con->data;
 
@@ -1220,7 +1227,7 @@ static void cdns_uart_console_write(struct console *co, const char *s,
 				unsigned int count)
 {
 	struct uart_port *port = console_port;
-	unsigned long flags = 0;
+	unsigned long flags;
 	unsigned int imr, ctrl;
 	int locked = 1;
 
@@ -1245,9 +1252,7 @@ static void cdns_uart_console_write(struct console *co, const char *s,
 	writel(ctrl, port->membase + CDNS_UART_CR);
 
 	uart_console_write(port, s, count, cdns_uart_console_putchar);
-	while ((readl(port->membase + CDNS_UART_SR) &
-			(CDNS_UART_SR_TXEMPTY | CDNS_UART_SR_TACTIVE)) !=
-			CDNS_UART_SR_TXEMPTY)
+	while (cdns_uart_tx_empty(port) != TIOCSER_TEMT)
 		cpu_relax();
 
 	/* restore interrupt state */
@@ -1272,6 +1277,7 @@ static int cdns_uart_console_setup(struct console *co, char *options)
 	int bits = 8;
 	int parity = 'n';
 	int flow = 'n';
+	unsigned long time_out;
 
 	if (!port->membase) {
 		pr_debug("console on " CDNS_UART_TTY_NAME "%i not present\n",
@@ -1282,8 +1288,25 @@ static int cdns_uart_console_setup(struct console *co, char *options)
 	if (options)
 		uart_parse_options(options, &baud, &parity, &bits, &flow);
 
+	/* Wait for tx_empty before setting up the console */
+	time_out = jiffies + usecs_to_jiffies(TX_TIMEOUT);
+
+	while (time_before(jiffies, time_out) &&
+	       cdns_uart_tx_empty(port) != TIOCSER_TEMT)
+		cpu_relax();
+
 	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
@@ -1302,7 +1325,7 @@ static int cdns_uart_suspend(struct device *device)
 	may_wake = device_may_wakeup(device);
 
 	if (console_suspend_enabled && uart_console(port) && may_wake) {
-		unsigned long flags = 0;
+		unsigned long flags;
 
 		spin_lock_irqsave(&port->lock, flags);
 		/* Empty the receive FIFO 1st before making changes */
@@ -1333,15 +1356,23 @@ static int cdns_uart_resume(struct device *device)
 {
 	struct uart_port *port = dev_get_drvdata(device);
 	struct cdns_uart *cdns_uart = port->private_data;
-	unsigned long flags = 0;
+	unsigned long flags;
 	u32 ctrl_reg;
 	int may_wake;
+	int ret;
 
 	may_wake = device_may_wakeup(device);
 
 	if (console_suspend_enabled && uart_console(port) && !may_wake) {
-		clk_enable(cdns_uart->pclk);
-		clk_enable(cdns_uart->uartclk);
+		ret = clk_enable(cdns_uart->pclk);
+		if (ret)
+			return ret;
+
+		ret = clk_enable(cdns_uart->uartclk);
+		if (ret) {
+			clk_disable(cdns_uart->pclk);
+			return ret;
+		}
 
 		spin_lock_irqsave(&port->lock, flags);
 
@@ -1390,9 +1421,17 @@ static int __maybe_unused cdns_runtime_resume(struct device *dev)
 {
 	struct uart_port *port = dev_get_drvdata(dev);
 	struct cdns_uart *cdns_uart = port->private_data;
+	int ret;
+
+	ret = clk_enable(cdns_uart->pclk);
+	if (ret)
+		return ret;
 
-	clk_enable(cdns_uart->pclk);
-	clk_enable(cdns_uart->uartclk);
+	ret = clk_enable(cdns_uart->uartclk);
+	if (ret) {
+		clk_disable(cdns_uart->pclk);
+		return ret;
+	}
 	return 0;
 };
 
@@ -1415,89 +1454,8 @@ 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
@@ -1507,16 +1465,11 @@ 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);
@@ -1526,64 +1479,35 @@ 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) {
@@ -1661,6 +1585,7 @@ 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.
@@ -1672,6 +1597,8 @@ static int cdns_uart_probe(struct platform_device *pdev)
 	port->dev = &pdev->dev;
 	port->uartclk = clk_get_rate(cdns_uart_data->uartclk);
 	port->private_data = cdns_uart_data;
+	port->read_status_mask = CDNS_UART_IXR_TXEMPTY | CDNS_UART_IXR_RXTRIG |
+			CDNS_UART_IXR_OVERRUN | CDNS_UART_IXR_TOUT;
 	cdns_uart_data->port = port;
 	platform_set_drvdata(pdev, port);
 
@@ -1688,11 +1615,13 @@ static int cdns_uart_probe(struct platform_device *pdev)
 	 * If register_console() don't assign value, then console_port pointer
 	 * is cleanup.
 	 */
-	if (!console_port)
+	if (!console_port) {
+		cdns_uart_console.index = id;
 		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);
@@ -1702,13 +1631,17 @@ 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;
+		cdns_uart_console.index = -1;
+	}
 #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:
@@ -1724,12 +1657,8 @@ 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;
 }
 
@@ -1752,10 +1681,6 @@ 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);
@@ -1768,13 +1693,8 @@ 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;
 }