[PATCH AUTOSEL 5.1 050/141] serial: uartps: Use the same dynamic major number for all ports

[Sasha Levin]

From: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>

[ Upstream commit ab262666018de6f4e206b021386b93ed0c164316 ]

Let kernel to find out major number dynamically for the first device and
then reuse it for other instances.
This fixes the issue that each uart is registered with a
different major number.

After the patch:
crw-------    1 root     root      253,   0 Jun 10 08:31 /dev/ttyPS0
crw--w----    1 root     root      253,   1 Jan  1  1970 /dev/ttyPS1

Fixes: 024ca329bfb9 ("serial: uartps: Register own uart console and driver structures")
Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
Signed-off-by: Michal Simek <michal.simek@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/tty/serial/xilinx_uartps.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/tty/serial/xilinx_uartps.c b/drivers/tty/serial/xilinx_uartps.c
index 74089f5e5b53..fd0aa1e4e5ad 100644
--- a/drivers/tty/serial/xilinx_uartps.c
+++ b/drivers/tty/serial/xilinx_uartps.c
@@ -29,12 +29,12 @@
 
 #define CDNS_UART_TTY_NAME	"ttyPS"
 #define CDNS_UART_NAME		"xuartps"
-#define CDNS_UART_MAJOR		0	/* use dynamic node allocation */
 #define CDNS_UART_FIFO_SIZE	64	/* FIFO size */
 #define CDNS_UART_REGISTER_SPACE	0x1000
 
 /* Rx Trigger level */
 static int rx_trigger_level = 56;
+static int uartps_major;
 module_param(rx_trigger_level, uint, S_IRUGO);
 MODULE_PARM_DESC(rx_trigger_level, "Rx trigger level, 1-63 bytes");
 
@@ -1507,7 +1507,7 @@ static int cdns_uart_probe(struct platform_device *pdev)
 	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 = CDNS_UART_MAJOR;
+	cdns_uart_uart_driver->major = uartps_major;
 	cdns_uart_uart_driver->minor = cdns_uart_data->id;
 	cdns_uart_uart_driver->nr = 1;
 
@@ -1536,6 +1536,7 @@ static int cdns_uart_probe(struct platform_device *pdev)
 		goto err_out_id;
 	}
 
+	uartps_major = cdns_uart_uart_driver->tty_driver->major;
 	cdns_uart_data->cdns_uart_driver = cdns_uart_uart_driver;
 
 	/*
-- 
2.20.1