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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。9 b$ P/ J v D P, M( C8 Z
*** DaVinci Core Type *** | |
" L3 u# C. a. r3 a# u | | [ ] DaVinci 644x based system | |5 M6 l7 J5 w, m. t4 z& h
| | [ ] DaVinci 355 based system | |
* h9 y( L) x) r( y1 z | | [ ] DaVinci 646x based system | |# ^9 Z. a4 v% ?0 I3 J; z6 }
| | [ ] DA830/OMAP-L137/AM17x based system | |3 Z1 G0 k& H) t- Z# K9 i0 e: L& I$ ?
| | [*] DA850/OMAP-L138/AM18x based system | |
" X1 f" W$ I+ g5 u" g! \ | | [ ] Enable UART1 flow control | |& T4 |/ g7 [' |0 W1 G1 L
| | [ ] Enable UART0 RS485 funcation | |
$ _# Y: P& U7 F& V5 W | | [*] Enable UART1 RS485 funcation 1 @; o# E3 Y4 H
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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；
% J. U+ Z# z2 x0 [0 K+ A- @void serial8250_tx_chars(struct uart_8250_port *up)/ A- J9 h. }) Z. f. }
return;
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0 l/ j2 J, P! z. n9 o5 j* j! m+ t+#if 1
4 C/ H7 w. ]; s8 H5 U+ /* The funcation with RS485 flow control */
- {0 f. v$ v I9 I5 q+ if (up->port.private_data) {
k- _/ ?. ^9 s0 {' d6 q, w/ N+ struct serial8250_flow_ctrl *flow_ctrl_p;
# c8 ]- ?% Z8 T+ flow_ctrl_p = up->port.private_data;
# {- ? z0 P) H! i# H' l+
! b9 q3 ~" y/ [$ A+ if (flow_ctrl_p->gpio) {
# \" f. |7 t; L+ gpio_set_value(flow_ctrl_p->gpio, 1);- g/ l8 ?0 k/ D& R/ N; x
+ ndelay(50); /* Propagation delay >= 50ns */
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+ }- I8 x. Y; w5 ~% |5 |2 O# M( {
+#endif
9 G( V& v0 O' o) W希望对您有帮助。; Q6 C$ Q( K5 W- V5 C, z
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发表于 2014-10-31 17:01:26
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