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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。
( @4 }4 `0 O- c9 x3 I *** DaVinci Core Type *** | |# z: _2 V' \" ^4 @
| | [ ] DaVinci 644x based system | |
4 g4 H' B* Y# X5 m$ J | | [ ] DaVinci 355 based system | |
X) \( C0 u6 Z1 {4 B! a | | [ ] DaVinci 646x based system | |
, D, u! \: f7 t, M2 Y | | [ ] DA830/OMAP-L137/AM17x based system | |5 Q3 S( y) ~- \" v* E4 }) u
| | [*] DA850/OMAP-L138/AM18x based system | |1 ~6 e- \+ \: a$ \0 q
| | [ ] Enable UART1 flow control | |
) Y, y- h# s9 I8 m* T | | [ ] Enable UART0 RS485 funcation | |
! e! Q8 ?" x3 { | | [*] Enable UART1 RS485 funcation V4 q3 q( M% r5 ^9 s
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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; \0 o: c# W! |8 Q1 Y- f z3 n* h
void serial8250_tx_chars(struct uart_8250_port *up)2 i- B" t$ a* s2 Z1 v& f
return;- r+ G; w& q4 K, V3 j& e
}
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+#if 1 \$ K7 |6 p: B0 p" R6 ^
+ /* The funcation with RS485 flow control */9 n5 W* J* M1 O
+ if (up->port.private_data) {
, W! R W& m' F- r4 a$ L+ struct serial8250_flow_ctrl *flow_ctrl_p;* b/ y; Y, z. B( f8 V8 r+ j
+ flow_ctrl_p = up->port.private_data;) U/ J3 A) |" p* Q* B- ~# n
+
1 w% | d- I2 p1 y# Z5 g9 H. I4 e5 a+ if (flow_ctrl_p->gpio) {
3 H Y6 k2 h7 r" Z+ gpio_set_value(flow_ctrl_p->gpio, 1);8 O; @* J4 N/ ~( D: x, t
+ ndelay(50); /* Propagation delay >= 50ns */; D2 A2 l& y4 q% l( j" y
+ }
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+#endif
- ]$ ]9 e- {3 D' c* J9 } N& t希望对您有帮助。
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