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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。5 Y* o K. Y$ P7 F
*** DaVinci Core Type *** | |
& s3 {/ @% X, w; y- l) V' @0 C | | [ ] DaVinci 644x based system | |
, \! T% b/ o; x3 `% c8 K4 @ | | [ ] DaVinci 355 based system | |; Z. b! @ x9 z6 m
| | [ ] DaVinci 646x based system | |
' l1 G& u2 t9 @* Y. i6 Z, a Z | | [ ] DA830/OMAP-L137/AM17x based system | |) N" z6 m6 W" G: u
| | [*] DA850/OMAP-L138/AM18x based system | |% X8 b x3 `5 x5 w' [$ L9 o
| | [ ] Enable UART1 flow control | |
0 ?& Q. o% j$ N1 U6 g5 B0 V | | [ ] Enable UART0 RS485 funcation | |; V* ?# T4 C3 f" [) Y2 ?
| | [*] 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;! _1 V) Q$ l+ I/ z) ~" C, i
void serial8250_tx_chars(struct uart_8250_port *up)% W0 A1 a5 Y$ V
return;
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0 b5 C- A9 A& L0 L- u9 W6 `+#if 1! O7 s4 [3 l( j; |$ n$ K P1 V% u. L
+ /* The funcation with RS485 flow control */# u) c& L1 ~# F; |2 b7 A) C
+ if (up->port.private_data) {
1 J! w0 b6 }1 n+ R1 p5 J+ struct serial8250_flow_ctrl *flow_ctrl_p;$ Z! F! h( C! L
+ flow_ctrl_p = up->port.private_data;' g6 j. n" u- g8 ~6 \1 a# K
+
4 F, I; l: }/ T) S0 L0 S a+ if (flow_ctrl_p->gpio) {
. C6 _+ l# V2 d9 M8 k+ gpio_set_value(flow_ctrl_p->gpio, 1);3 ?8 I% X' Z: a9 v% Y% n1 x2 K ~+ V
+ ndelay(50); /* Propagation delay >= 50ns */
' Q. I9 B3 E+ _1 N( ?! F" n6 F+ }
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+#endif
3 L# o0 [8 w& h* r8 I希望对您有帮助。
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