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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。
) c% ^* J9 m) v3 s D P P *** DaVinci Core Type *** | |8 S1 c3 ~& J2 T' {
| | [ ] DaVinci 644x based system | |
+ |* Q! o+ D. c | | [ ] DaVinci 355 based system | |8 {# K' ] t% ^6 f, J" x% |
| | [ ] DaVinci 646x based system | |9 j5 T# W$ I+ Y" r6 Z% @# _5 z
| | [ ] DA830/OMAP-L137/AM17x based system | |6 a4 j% v7 J: d. f c
| | [*] DA850/OMAP-L138/AM18x based system | |
0 ]& p7 Z' o1 x" J | | [ ] Enable UART1 flow control | |
4 ]8 n9 F% a. O: G+ g+ p9 t; [9 K | | [ ] Enable UART0 RS485 funcation | |
' d9 s5 P3 ]6 J# C& B# A2 b; j | | [*] Enable UART1 RS485 funcation
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1 \. F) {/ ]+ z, ?想了解详细的功能实现,也可以查看8250.c文件里面的;: |; y2 V, d6 s
void serial8250_tx_chars(struct uart_8250_port *up)+ e, p: y; y- e" _2 g" T2 _
return;
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+#if 1
2 Y" V0 q" H1 a( U8 O/ `+ /* The funcation with RS485 flow control */+ Y4 a6 g7 s9 T& w
+ if (up->port.private_data) {% o9 Y; ~# C. [$ ?9 C
+ struct serial8250_flow_ctrl *flow_ctrl_p;1 }- O& C2 e5 C$ `0 P J3 t' m; k
+ flow_ctrl_p = up->port.private_data;8 p9 r: e6 w7 t/ ^/ o
+( X7 @, g/ H6 N
+ if (flow_ctrl_p->gpio) {# E- }5 r6 q4 A6 r5 m: p
+ gpio_set_value(flow_ctrl_p->gpio, 1);
1 r* \4 Y! P& B/ ~+ ndelay(50); /* Propagation delay >= 50ns */, w: u5 |* {( M/ z+ R5 X
+ }
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, `* ]- ]$ C8 o1 d7 Q+#endif/ g1 S& Q& @) p6 b8 n) F
希望对您有帮助。
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