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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。2 I T9 G; s: I; R O# q, _
*** DaVinci Core Type *** | |. z6 H7 y; t. i3 p* U
| | [ ] DaVinci 644x based system | |: p, v$ _3 N U; t
| | [ ] DaVinci 355 based system | |. N$ h. p/ |- M' g# E; _
| | [ ] DaVinci 646x based system | |
8 X# M( i5 b% g( F6 z" O | | [ ] DA830/OMAP-L137/AM17x based system | |
7 m$ N( C3 j" b) {. y5 l I; |- a | | [*] DA850/OMAP-L138/AM18x based system | |1 u! G/ O, |& `# Q4 {$ Y! t' u# W
| | [ ] Enable UART1 flow control | |
1 p( V9 |0 r3 @; V8 D, j' T | | [ ] Enable UART0 RS485 funcation | |2 S0 {4 Y4 ^2 k+ M( v
| | [*] Enable UART1 RS485 funcation ( S; M5 t5 A) i+ ]
4 x# d; d" y6 |" e想了解详细的功能实现，也可以查看8250.c文件里面的；
( q) n. o F# svoid serial8250_tx_chars(struct uart_8250_port *up) a4 H+ `0 k6 o! J8 w
return;
2 j) r8 V, i/ I' s/ y* y# d }
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+#if 1
% A" R' s k5 w! h+ /* The funcation with RS485 flow control */
; h2 F* H/ y& T" Q" W1 s+ if (up->port.private_data) {
( M8 _8 x$ Z, w+ t( a7 u% n6 Q+ struct serial8250_flow_ctrl *flow_ctrl_p;7 s% \$ y1 U% B2 y3 V/ S
+ flow_ctrl_p = up->port.private_data;3 O `3 |/ Q2 G8 A2 ]
+
" H; O* k& u' J+ if (flow_ctrl_p->gpio) {) }. v* b& ~" b F0 W X7 y0 ]
+ gpio_set_value(flow_ctrl_p->gpio, 1);9 x6 O" b9 Y( W. [; n! ?
+ ndelay(50); /* Propagation delay >= 50ns */9 |1 Q, F5 {$ V! v3 V: c$ W( V
+ }' y. A/ \/ x: S( O+ Z3 @0 W
+ }/ ^' D6 y; V! ^$ a- I: G/ h
+#endif" I- |0 i) ` v& B9 m; R
希望对您有帮助。
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|手机版|小黑屋|嵌入式开发者社区
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发表于 2014-10-31 17:01:26
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