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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。
! k7 a, j' i% `% M' @5 m *** DaVinci Core Type *** | |5 ] y# P' S7 z8 Q
| | [ ] DaVinci 644x based system | |. W; W: T8 F8 X
| | [ ] DaVinci 355 based system | |
) u, t) q8 Z. ]/ z3 x | | [ ] DaVinci 646x based system | |4 ? ~* \ I* b7 b) j. A
| | [ ] DA830/OMAP-L137/AM17x based system | |
% U5 K/ p. W4 r1 w | | [*] DA850/OMAP-L138/AM18x based system | |
0 `* F7 { [ o& c | | [ ] Enable UART1 flow control | |
4 L/ X4 R/ M4 u1 s& J | | [ ] Enable UART0 RS485 funcation | |/ H$ Y" g! `4 o) {3 p5 I4 N
| | [*] Enable UART1 RS485 funcation
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5 k8 i- @- l: `想了解详细的功能实现,也可以查看8250.c文件里面的;
' V# I N, ^. w9 lvoid serial8250_tx_chars(struct uart_8250_port *up): J9 g9 Y7 m. c$ h2 J0 e. P. E
return;
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+#if 1
: d7 G# r; M# S' n+ /* The funcation with RS485 flow control */
& u& l& ^& }6 e0 t+ L+ if (up->port.private_data) {+ d" P: Y$ g: w: f) X. H) l
+ struct serial8250_flow_ctrl *flow_ctrl_p;4 Q' A) W9 X9 |. k* D( Y# l Y
+ flow_ctrl_p = up->port.private_data;0 w Z9 y/ \7 v9 m- ?) J5 W a9 w3 }$ O
+/ G6 t# `) j. Z4 f4 S: {
+ if (flow_ctrl_p->gpio) {5 j3 I0 K/ u9 z5 S5 l
+ gpio_set_value(flow_ctrl_p->gpio, 1);
9 M/ C3 P" t' G: v" [/ E7 i+ ndelay(50); /* Propagation delay >= 50ns */1 ]7 T7 g5 g. W% x+ w6 \6 m
+ }
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# k. X* }" ?3 P2 p$ ~; M$ A- q+#endif; Q2 W8 Q4 v" _8 s5 M0 i
希望对您有帮助。 [) r3 I$ D! }1 `3 ?( q
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