[PATCH 2/2] serial: uartps: Use the same dynamin major number for all ports

From: Michal Simek
Date: Mon Jun 10 2019 - 04:49:30 EST


From: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>

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

Signed-off-by: Shubhrajyoti Datta <shubhrajyoti.datta@xxxxxxxxxx>
Signed-off-by: Michal Simek <michal.simek@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 6af2886f5ba7..a0b51c60faeb 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, 0444);
MODULE_PARM_DESC(rx_trigger_level, "Rx trigger level, 1-63 bytes");

@@ -1516,7 +1516,7 @@ 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;

@@ -1545,6 +1545,7 @@ 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;

/*
--
2.17.1