tty: goldfish: support platform_device with id -1

When the platform bus sets the platform_device id to -1 (PLATFORM_DEVID_NONE),
use an incrementing counter for the TTY index instead
Signed-off-by: NGreg Hackmann <ghackmann@google.com>
Signed-off-by: NJin Qian <jinqian@android.com>
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/goldfish.c

@@ -68,8 +68,7 @@ static void goldfish_tty_do_write(int line, const char *buf, unsigned count)
 
 static irqreturn_t goldfish_tty_interrupt(int irq, void *dev_id)
 {
-	struct platform_device *pdev = dev_id;
-	struct goldfish_tty *qtty = &goldfish_ttys[pdev->id];
+	struct goldfish_tty *qtty = dev_id;
 	void __iomem *base = qtty->base;
 	unsigned long irq_flags;
 	unsigned char *buf;
@@ -233,6 +232,7 @@ static int goldfish_tty_probe(struct platform_device *pdev)
 	struct device *ttydev;
 	void __iomem *base;
 	u32 irq;
+	unsigned int line;
 
 	r = platform_get_resource(pdev, IORESOURCE_MEM, 0);
 	if (r == NULL)
@@ -248,10 +248,16 @@ static int goldfish_tty_probe(struct platform_device *pdev)
 
 	irq = r->start;
 
-	if (pdev->id >= goldfish_tty_line_count)
-		goto err_unmap;
-
 	mutex_lock(&goldfish_tty_lock);
+
+	if (pdev->id == PLATFORM_DEVID_NONE)
+		line = goldfish_tty_current_line_count;
+	else
+		line = pdev->id;
+
+	if (line >= goldfish_tty_line_count)
+		goto err_create_driver_failed;
+
 	if (goldfish_tty_current_line_count == 0) {
 		ret = goldfish_tty_create_driver();
 		if (ret)
@@ -259,7 +265,7 @@ static int goldfish_tty_probe(struct platform_device *pdev)
 	}
 	goldfish_tty_current_line_count++;
 
-	qtty = &goldfish_ttys[pdev->id];
+	qtty = &goldfish_ttys[line];
 	spin_lock_init(&qtty->lock);
 	tty_port_init(&qtty->port);
 	qtty->port.ops = &goldfish_port_ops;
@@ -269,13 +275,13 @@ static int goldfish_tty_probe(struct platform_device *pdev)
 	writel(GOLDFISH_TTY_CMD_INT_DISABLE, base + GOLDFISH_TTY_CMD);
 
 	ret = request_irq(irq, goldfish_tty_interrupt, IRQF_SHARED,
-						"goldfish_tty", pdev);
+						"goldfish_tty", qtty);
 	if (ret)
 		goto err_request_irq_failed;
 
 
 	ttydev = tty_port_register_device(&qtty->port, goldfish_tty_driver,
-							pdev->id, &pdev->dev);
+							line, &pdev->dev);
 	if (IS_ERR(ttydev)) {
 		ret = PTR_ERR(ttydev);
 		goto err_tty_register_device_failed;
@@ -286,8 +292,9 @@ static int goldfish_tty_probe(struct platform_device *pdev)
 	qtty->console.device = goldfish_tty_console_device;
 	qtty->console.setup = goldfish_tty_console_setup;
 	qtty->console.flags = CON_PRINTBUFFER;
-	qtty->console.index = pdev->id;
+	qtty->console.index = line;
 	register_console(&qtty->console);
+	platform_set_drvdata(pdev, qtty);
 
 	mutex_unlock(&goldfish_tty_lock);
 	return 0;
@@ -307,13 +314,12 @@ static int goldfish_tty_probe(struct platform_device *pdev)
 
 static int goldfish_tty_remove(struct platform_device *pdev)
 {
-	struct goldfish_tty *qtty;
+	struct goldfish_tty *qtty = platform_get_drvdata(pdev);
 
 	mutex_lock(&goldfish_tty_lock);
 
-	qtty = &goldfish_ttys[pdev->id];
 	unregister_console(&qtty->console);
-	tty_unregister_device(goldfish_tty_driver, pdev->id);
+	tty_unregister_device(goldfish_tty_driver, qtty->console.index);
 	iounmap(qtty->base);
 	qtty->base = NULL;
 	free_irq(qtty->irq, pdev);