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您好！tronlong提供的最新的linux3.3内核已经对uart0和uart1做了rs485功能的支持，uart2默认为启动串口。如何想使能uart0和uart1 rs485的功能，只需在menuconfig将485使能。" W+ w0 e: `" A4 ]/ h8 ?
*** DaVinci Core Type *** | |
/ S6 G6 y' H% [$ t; R | | [ ] DaVinci 644x based system | |
& F0 p+ J Y: n8 ` | | [ ] DaVinci 355 based system | |
2 `2 ~0 M |( b | | [ ] DaVinci 646x based system | |
1 Y2 K6 Z3 U+ f. G3 B8 D' M e6 K3 Z; M | | [ ] DA830/OMAP-L137/AM17x based system | |
# z- S# Y' D+ v! w0 u( o | | [*] DA850/OMAP-L138/AM18x based system | |
; `9 h. u0 d8 J8 f# @" R) O | | [ ] Enable UART1 flow control | |5 t( s/ | c9 _, N$ Y+ c
| | [ ] Enable UART0 RS485 funcation | |# H2 S, U& c, B
| | [*] Enable UART1 RS485 funcation ; U4 z4 G5 {' W! @+ M z
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想了解详细的功能实现，也可以查看8250.c文件里面的；
( ?1 ?$ d; M& zvoid serial8250_tx_chars(struct uart_8250_port *up)
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}
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+#if 17 E: u+ e! _6 c& ]' o$ Q
+ /* The funcation with RS485 flow control */
! T" b7 i+ D, \* N3 v+ if (up->port.private_data) {
`/ G0 M) W( C' }% c+ struct serial8250_flow_ctrl *flow_ctrl_p;8 ]! H: f. i1 G8 s: I
+ flow_ctrl_p = up->port.private_data;4 a# g# L4 m# V8 {; n- \# h
+
- U) k3 ?! X& K+ if (flow_ctrl_p->gpio) {" Q7 h& b* s9 J3 ]% r
+ gpio_set_value(flow_ctrl_p->gpio, 1);' u9 c5 h" E0 k2 i
+ ndelay(50); /* Propagation delay >= 50ns */" Y9 G [% `4 e: t* B; O7 w1 r
+ }
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+#endif4 `& y. M8 ]% V3 D/ E, y. e
希望对您有帮助。. x' H7 B m. e9 E
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发表于 2014-10-31 17:21:45