Hi Gururaja,

For our upcoming SOC, we have a situation where in we need to configure UART console at runtime. Our SOC makes use of NS16550.

I looked through the u-boot tree & found several references for doing the same.

hebbar@linux- server:~/projects/u-boot-git$ gr NS16550_init * board/sheldon/simpc8313/simpc8313.c:145: NS16550_init((NS16550_t)(CONFIG_SYS_IMMR + 0x4500), board/ml2/serial.c:45: (void) NS16550_init (COM_PORTS[0], clock_divisor); board/ml2/serial.c:48: (void) NS16550_init (COM_PORTS[1], clock_divisor); board/MAI/AmigaOneG3SE/serial.c:157: NS16550_init (Com0, clock_divisor); board/MAI/AmigaOneG3SE/serial.c:244: NS16550_init (Com0, clock_divisor); board/freescale/mpc8313erdb/mpc8313erdb.c:138: NS16550_init((NS16550_t)(CONFIG_SYS_IMMR + 0x4500), board/freescale/mpc8315erdb/mpc8315erdb.c:239: NS16550_init((NS16550_t)(CONFIG_SYS_IMMR + 0x4500), board/bmw/serial.c:45: NS16550_init (CONFIG_CONS_INDEX - 1, clock_divisor); board/bmw/ns16550.c:16:volatile struct NS16550 *NS16550_init (int chan, int baud_divisor) board/mvblue/mvblue.c:45: NS16550_init (console, clock_divisor); board/Marvell/common/serial.c:101: (void) NS16550_init (0, clock_divisor); board/Marvell/common/serial.c:104: (void) NS16550_init (1, clock_divisor); board/Marvell/common/ns16550.c:20:volatile struct NS16550 *NS16550_init (int chan, int baud_divisor) board/Marvell/common/ns16550.h:92:volatile struct NS16550 * NS16550_init(int chan, int baud_divisor); board/amirix/ap1000/serial.c:43: (void) NS16550_init (COM_PORTS[0], clock_divisor); board/evb64260/serial.c:103: (void)NS16550_init(COM_PORTS[0], clock_divisor); board/evb64260/serial.c:106: (void)NS16550_init(COM_PORTS[1], clock_divisor);

I would like to know whether this approach is correct and whether this approach is still allowed in current u-boot.

We know that this situation is really, ahem, far from perfect but no one took the time to rewrite that to use only common infrastructure.

If not, what is the correct approach? I am also looking at CONFIG_SERIAL_MULTI.

We should strive to handle _all_ 16550 compatible parts with only one driver. Actually this should be drivers/serial/ns16550.c. Please try to fit this into your upcoming port. (Only recently we did indeed remove some more duplicates of this code.)

Thanks (also in advance) Detlev