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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 R6 j; P+ e9 {; x *** DaVinci Core Type *** | |3 N# T, b1 {$ Q% {! D
| | [ ] DaVinci 644x based system | |. _$ X+ b5 L- A
| | [ ] DaVinci 355 based system | |
5 m- c' f( o0 j$ E8 Z6 o | | [ ] DaVinci 646x based system | |' Z6 |' G; G0 h4 j5 Y; i. A2 X2 a
| | [ ] DA830/OMAP-L137/AM17x based system | |
; }2 ]( k! X; J | | [*] DA850/OMAP-L138/AM18x based system | |' t$ D- Y. @3 ?, K3 G) e; U2 o; u8 V3 \
| | [ ] Enable UART1 flow control | |# F) ~5 K. Y4 P$ d! C
| | [ ] Enable UART0 RS485 funcation | |
3 ?! w4 M6 ^ u! z* g2 ? | | [*] Enable UART1 RS485 funcation ) W, a; e# y% j6 v7 W4 A
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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;( n- ?0 X1 v$ T4 r3 [3 p
void serial8250_tx_chars(struct uart_8250_port *up)( e, J, b7 b. Z" j3 v. d
return;
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" N \! s3 b2 A9 i: d& H8 z+#if 1* i3 E" o+ C9 D
+ /* The funcation with RS485 flow control */; b4 a9 Z+ \" W6 L& m- O
+ if (up->port.private_data) {9 x3 V9 ?& ~: V I7 x4 k2 p+ W
+ struct serial8250_flow_ctrl *flow_ctrl_p;, X, o: O( F% n, o
+ flow_ctrl_p = up->port.private_data;
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& n7 c1 p B" J; N% W+ if (flow_ctrl_p->gpio) {3 S( b0 @: w3 o8 K$ K3 ~' F8 l
+ gpio_set_value(flow_ctrl_p->gpio, 1);
& o, n$ U' R& u; J2 V! [4 B+ ndelay(50); /* Propagation delay >= 50ns */
, |& `/ m5 D& Z/ Q$ A+ }
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* d7 T. u0 x1 y5 M8 m+#endif
0 X( K2 c% t( j0 B' N希望对您有帮助。
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