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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。 W6 B% X$ v* X% n# Q& `# o$ ?
*** DaVinci Core Type *** | |
9 e' T6 h9 w) c# b5 A9 I | | [ ] DaVinci 644x based system | |! Y2 }/ y$ R9 T6 R
| | [ ] DaVinci 355 based system | |
, F) e* n$ `% v8 z4 G1 p7 F | | [ ] DaVinci 646x based system | |- _) E! ]+ ?* c: B! y9 h: @
| | [ ] DA830/OMAP-L137/AM17x based system | |
$ V2 }; v' e" ^! ~+ ~& A/ x | | [*] DA850/OMAP-L138/AM18x based system | |
7 V1 \2 n4 u3 X8 M* c$ S | | [ ] Enable UART1 flow control | |
: V* q/ o6 V" o | | [ ] Enable UART0 RS485 funcation | |
, E2 |! _2 F7 N3 z1 E | | [*] Enable UART1 RS485 funcation
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4 y$ k9 ~ H, P/ [: ]: a: ^: [1 E想了解详细的功能实现,也可以查看8250.c文件里面的;& \5 v& U9 b- Z2 u6 l& ^
void serial8250_tx_chars(struct uart_8250_port *up)* [7 C6 r% b. {
return;+ D* }2 p6 k8 y) F: N
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+#if 1. ^- M7 ]/ z* W0 U
+ /* The funcation with RS485 flow control */% Y& L+ J. w1 B
+ if (up->port.private_data) {
$ ]% n! D7 R" G8 w4 h+ struct serial8250_flow_ctrl *flow_ctrl_p;4 F* s2 z0 A/ C& y9 R
+ flow_ctrl_p = up->port.private_data;2 i; G" H! j& `, g& W/ s7 C
+7 D7 _$ F% i. H0 O" @! |/ t
+ if (flow_ctrl_p->gpio) {
: O, o7 p1 x$ `" k, t! m( i+ Q+ gpio_set_value(flow_ctrl_p->gpio, 1);# G; V3 g/ g3 Z5 a$ e1 g6 Y
+ ndelay(50); /* Propagation delay >= 50ns */" Y, `+ p4 t2 y4 H% R% \
+ }
9 Y, w& ~8 V0 G" u( }$ U7 r3 w+ }
+ k3 R' D- v# k4 m& [" P- _( s+#endif
, K7 D, R5 x7 l3 K) U希望对您有帮助。
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