Update ttyUL major number allocation details in documentation.
Use dynamic allocation for major number when uart ports > 4.
---
Changes for V2:
Introduce 1/2 patch.
Update driver to use either static or dynamic major allocation.
Update commit description.
Update description of SERIAL_UARTLITE_NR_UARTS in Kconfig.
Changes for V3:
Fix typo.
Move description to above of ttyUL.
Remove parentheses.
Changes for V4:
Fix typo.
Manikanta Guntupalli (2):
Documentation: devices.txt: Update ttyUL major number allocation
details
serial: uartlite: Use dynamic allocation for major number when uart
ports > 4
Documentation/admin-guide/devices.txt | 3 +++
drivers/tty/serial/Kconfig | 3 +++
drivers/tty/serial/uartlite.c | 5 +++++
3 files changed, 11 insertions(+)
--
2.25.1
Device number 204 has a range of minors on major number.
uart_register_driver is failing due to lack of minor numbers
when more number of uart ports used. So, to avoid minor number
limitation on 204 major number use dynamic major allocation
when more than 4 uart ports used otherwise use static major
allocation.
https://docs.kernel.org/arch/arm/sa1100/serial_uart.html
Signed-off-by: Manikanta Guntupalli <[email protected]>
---
Changes for V2:
Update logic to use either static or dynamic major allocation.
Update commit description.
Update description of SERIAL_UARTLITE_NR_UARTS in Kconfig.
Changes for V3:
Fix typo.
Remove parentheses.
Changes for V4:
Fix typo.
---
drivers/tty/serial/Kconfig | 3 +++
drivers/tty/serial/uartlite.c | 5 +++++
2 files changed, 8 insertions(+)
diff --git a/drivers/tty/serial/Kconfig b/drivers/tty/serial/Kconfig
index 732c893c8d16..8b1f5756002f 100644
--- a/drivers/tty/serial/Kconfig
+++ b/drivers/tty/serial/Kconfig
@@ -532,6 +532,9 @@ config SERIAL_UARTLITE_NR_UARTS
help
Set this to the number of uartlites in your system, or the number
you think you might implement.
+ If maximum number of uartlite serial ports is more than 4, then the
+ driver uses dynamic allocation instead of static allocation for major
+ number.
config SERIAL_SUNCORE
bool
diff --git a/drivers/tty/serial/uartlite.c b/drivers/tty/serial/uartlite.c
index 404c14acafa5..66d751edcf45 100644
--- a/drivers/tty/serial/uartlite.c
+++ b/drivers/tty/serial/uartlite.c
@@ -24,8 +24,13 @@
#include <linux/pm_runtime.h>
#define ULITE_NAME "ttyUL"
+#if CONFIG_SERIAL_UARTLITE_NR_UARTS > 4
+#define ULITE_MAJOR 0 /* use dynamic node allocation */
+#define ULITE_MINOR 0
+#else
#define ULITE_MAJOR 204
#define ULITE_MINOR 187
+#endif
#define ULITE_NR_UARTS CONFIG_SERIAL_UARTLITE_NR_UARTS
/* ---------------------------------------------------------------------
--
2.25.1
Describe when uartlite driver uses static/dynamic allocation for major
number based on maximum number of uartlite serial ports.
Signed-off-by: Manikanta Guntupalli <[email protected]>
---
Changes for V2:
This patch introduced in V2.
Changes for V3:
Fix typo.
Move description to above of ttyUL.
Changes for V4:
Fix typo.
---
Documentation/admin-guide/devices.txt | 3 +++
1 file changed, 3 insertions(+)
diff --git a/Documentation/admin-guide/devices.txt b/Documentation/admin-guide/devices.txt
index 839054923530..94c98be1329a 100644
--- a/Documentation/admin-guide/devices.txt
+++ b/Documentation/admin-guide/devices.txt
@@ -2704,6 +2704,9 @@
...
185 = /dev/ttyNX15 Hilscher netX serial port 15
186 = /dev/ttyJ0 JTAG1 DCC protocol based serial port emulation
+
+ If maximum number of uartlite serial ports is more than 4, then the driver
+ uses dynamic allocation instead of static allocation for major number.
187 = /dev/ttyUL0 Xilinx uartlite - port 0
...
190 = /dev/ttyUL3 Xilinx uartlite - port 3
--
2.25.1