Hi Marek,
On 09/13/2012 10:17 AM, Marek Vasut wrote:
Dear José Miguel Gonçalves,
Hi Marek,
On 09/12/2012 10:01 PM, Marek Vasut wrote:
Dear José Miguel Gonçalves,
Serial driver for the S3C24XX SoCs.
Signed-off-by: José Miguel Gonçalves jose.goncalves@inov.pt
drivers/serial/Makefile | 1 + drivers/serial/s3c24xx_serial.c | 146
+++++++++++++++++++++++++++++++++++++++ 2 files changed, 147 insertions(+)
create mode 100644 drivers/serial/s3c24xx_serial.c
diff --git a/drivers/serial/Makefile b/drivers/serial/Makefile index 65d0f23..2cbdaac 100644 --- a/drivers/serial/Makefile +++ b/drivers/serial/Makefile @@ -52,6 +52,7 @@ COBJS-$(CONFIG_PL011_SERIAL) += serial_pl01x.o
COBJS-$(CONFIG_PXA_SERIAL) += serial_pxa.o COBJS-$(CONFIG_SA1100_SERIAL) += serial_sa1100.o COBJS-$(CONFIG_S3C24X0_SERIAL) += serial_s3c24x0.o
+COBJS-$(CONFIG_S3C24XX_SERIAL) += s3c24xx_serial.o
What's the difference between those two drivers ?!
No substantial differences exists. The UART controller block is the same in all S3C24XX chips. One difference is the number of UARTs. The more recent chips (S3C2416 & S3C2450) have 4 instead of the 3 found on the old ones. Besides that, the driver that I submitted uses a more precise method for baudrate generation.
So we will have two drivers for the same hardware? No way ... Use the original one and apply incremental patches onto it to improve it.
+#ifdef CONFIG_SERIAL0 +#define UART_NR S3C24XX_UART0
+#elif defined(CONFIG_SERIAL1) +#define UART_NR S3C24XX_UART1
+#elif defined(CONFIG_SERIAL2) +#define UART_NR S3C24XX_UART2
+#elif defined(CONFIG_SERIAL3) +#define UART_NR S3C24XX_UART3
+#else +#error "Bad: you didn't configure serial ..."
Error itself is "Bad:" so remove it
OK.
+#endif
+#define barrier() asm volatile("" ::: "memory")
Is that even used ?
Yes. Without it the GCC optimization removes the loop at the end of the baurate generation routine.
So it's yet another accessor issue. [...]
But anyway, there's more. I'd like to teach you how to do things properly. So let's focus on the in-tree driver and fix that one. Incrementally and in small steps.
OK, I will figure out the best way to do this. If I have any doubts I'll be back to you...
Best regards, José Gonçalves