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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。
8 n T5 A2 q; F *** DaVinci Core Type *** | |+ k5 z# R( \( A! T- M
| | [ ] DaVinci 644x based system | |6 L5 B U% f+ A/ Y9 v/ Y+ w7 D
| | [ ] DaVinci 355 based system | |# J8 n4 @+ `) { s9 H; Y8 c
| | [ ] DaVinci 646x based system | |
/ U0 M9 j% X5 T& x4 ]' J | | [ ] DA830/OMAP-L137/AM17x based system | |9 f! h/ I: x/ p: m( V; Y+ I
| | [*] DA850/OMAP-L138/AM18x based system | |- G& l& o# E$ P+ m5 g: R8 [+ ?! A2 ~
| | [ ] Enable UART1 flow control | |
* n$ @3 P4 X( j l | | [ ] Enable UART0 RS485 funcation | |, ~. d+ r3 a& f$ l. v5 h! b
| | [*] Enable UART1 RS485 funcation
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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；5 ^2 _+ w: H4 X7 E, o2 L& s! c
void serial8250_tx_chars(struct uart_8250_port *up)/ M' i/ E5 }& \
return;
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+#if 1
! u1 A' P% Q8 P( [8 U2 ^! e+ /* The funcation with RS485 flow control */' S. t# O! k' K7 u
+ if (up->port.private_data) {
7 L4 \. ]. P1 N8 y. }+ struct serial8250_flow_ctrl *flow_ctrl_p;
- n2 i S( X6 E1 F# `+ l+ flow_ctrl_p = up->port.private_data;: \, c z! T; P+ w% T; g
+
7 c! d" j; `+ q5 U+ if (flow_ctrl_p->gpio) {6 D$ P& H5 g5 k" l/ @- V
+ gpio_set_value(flow_ctrl_p->gpio, 1);2 r, v: A& M: W4 e% I9 D
+ ndelay(50); /* Propagation delay >= 50ns */8 f6 s- R% Z6 K, [. D8 T4 u Y
+ }: Z; R+ y0 r) u7 U' n- ?
+ }
& }; q% x4 Z; d" G+#endif
, O* X# {3 [+ D2 s9 s6 \8 f希望对您有帮助。5 W7 _$ E4 c {1 x* X( W
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发表于 2014-10-31 17:01:26
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