help!!! How can i use uart1(ttyS1) on DM365

jian zhang19638

i want to use ttyS1 to transmit and receive data.(my program worked very well by ttyS0)

in /dev, i can find ttyS0 and ttyS1

when boot the kernel, it shows :

Serial: 8250/16550 driver $Revision: 1.90 $ 2 ports, IRQ sharing disabled
serial8250.0: ttyS0 at MMIO map 0x1c20000 mem 0xfbc20000 (irq = 40) is a 16550A
serial8250.0: ttyS1 at MMIO map 0x1d06000 mem 0xfbd06000 (irq = 41) is a 16550A

when i transmit some data by ttyS1,it shows:

serinfo:1.0 driver revision:
0: uart:16550A mmio:0x01C20000 irq:40 membase 0xFBC20000 tx:5764 rx:53 RTS|CTS|D
TR|DSR
1: uart:16550A mmio:0x01D06000 irq:41 membase 0xFBD06000 tx:19104 rx:0 RTS|CTS|D
TR|DSR

it transmit some dates, but i receive nothing!!!

i using the default kernel, someone said maybe i must change the following file,

/ti-davinci/linux-2.6.18_pro500/arch/arm/mach-davinci/mux_cfg.c

in my system, it shows as follow:

265 MUX_CFG("UART0_RXD",             3,   20,    1,   1,     0)
266 MUX_CFG("UART0_TXD",             3,   19,    1,   1,     0)
267 MUX_CFG("UART1_RXD",           3,   17,    3,   2,     0)
269 MUX_CFG("UART1_TXD",           3,   15,    3,   2,     0)
271 MUX_CFG("UART1_RTS",             3,   23,    3,   1,     0)
272 MUX_CFG("UART1_CTS",             3,   21,    3,   1,     0)
273
274 MUX_CFG("EMAC_TX_EN",            3,   17,    3,   1,     0)
275 MUX_CFG("EMAC_TX_CLK",           3,   15,    3,   1,     0)

so who can tell me how to resolve this problem, how to use ttyS1

thx

over 14 years ago

0 John Anderson over 14 years ago

Genius 5240 points

You need to make sure the pins on your serial port match the MUX_CFG statements. There are two different locations that they can be assigned.

John A

0 jian zhang19638 over 14 years ago in reply to John Anderson

Intellectual 285 points

hi John, thank you for your reply

could you tell me more clearly about the two locations?

i find in the dm365 UART1 RXD muxed GIO034, UART1 TXD muxed GIO025, so how do i set the parameters in the MUX_CFG like MUX_CFG("UART1_TXD", 3, 15, 3, 2, 0).

thx

0 John Anderson over 14 years ago in reply to jian zhang19638

Genius 5240 points

I added these two statements to the init code for my board located in the kernel. This is necessary to make sure the pins are assigned and selected.

// Configure UART1
davinci_cfg_reg(DM365_UART1_TXD);
davinci_cfg_reg(DM365_UART1_RXD);

Of the top of my head I can't confirm that your MUX_CFG statement is correct for GIO034 and GIO025, so you might want to make sure that you are using the correct pins for your specific board.

John A

0 jian zhang19638 over 14 years ago in reply to John Anderson

Intellectual 285 points

thanks for your reply，

i have found the two location of uart1, and resolve this problem :)

0 Lokesh Kumar63254 over 14 years ago in reply to jian zhang19638

Prodigy 10 points

Can any one tell, how to configure UART1 so that i will be able to read and write through UART1. I have enabled the UART1 and also GIO16 and 17 pins as out and in respectively.

I have also set the UART1 Registers to work in FIFO mode.

can any one tell is some thing else i am missing in enabling the UART1 to read and write.

Thanks in advance,

Lokesh

0 John Anderson over 14 years ago in reply to Lokesh Kumar63254

Genius 5240 points

Lokesh,

Along with what's posted here, read this thread...

http://e2e.ti.com/support/embedded/f/354/p/75483/274257.aspx#274257

John A

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help!!! How can i use uart1(ttyS1) on DM365