14e2277962
while others dislike them being extra commits, let's clean them up once and for all for the existing code. If it's ugly, let it only be ugly once :-) Signed-off-by: Stefan Reinauer <stepan@coresystems.de> Acked-by: Stefan Reinauer <stepan@coresystems.de> git-svn-id: svn://svn.coreboot.org/coreboot/trunk@5507 2b7e53f0-3cfb-0310-b3e9-8179ed1497e1
91 lines
2.0 KiB
C
91 lines
2.0 KiB
C
/* Should support 8250, 16450, 16550, 16550A type uarts */
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#include <arch/io.h>
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#include <uart8250.h>
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/* Data */
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#define UART_RBR 0x00
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#define UART_TBR 0x00
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/* Control */
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#define UART_IER 0x01
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#define UART_IIR 0x02
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#define UART_FCR 0x02
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#define UART_LCR 0x03
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#define UART_MCR 0x04
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#define UART_DLL 0x00
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#define UART_DLM 0x01
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/* Status */
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#define UART_LSR 0x05
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#define UART_MSR 0x06
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#define UART_SCR 0x07
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static inline int uart8250_can_tx_byte(unsigned base_port)
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{
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return inb(base_port + UART_LSR) & 0x20;
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}
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static inline void uart8250_wait_to_tx_byte(unsigned base_port)
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{
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while(!uart8250_can_tx_byte(base_port))
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;
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}
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static inline void uart8250_wait_until_sent(unsigned base_port)
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{
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while(!(inb(base_port + UART_LSR) & 0x40))
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;
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}
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void uart8250_tx_byte(unsigned base_port, unsigned char data)
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{
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uart8250_wait_to_tx_byte(base_port);
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outb(data, base_port + UART_TBR);
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/* Make certain the data clears the fifos */
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uart8250_wait_until_sent(base_port);
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}
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int uart8250_can_rx_byte(unsigned base_port)
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{
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return inb(base_port + UART_LSR) & 0x01;
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}
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unsigned char uart8250_rx_byte(unsigned base_port)
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{
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while(!uart8250_can_rx_byte(base_port))
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;
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return inb(base_port + UART_RBR);
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}
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void uart8250_init(unsigned base_port, unsigned divisor, unsigned lcs)
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{
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lcs &= 0x7f;
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/* disable interrupts */
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outb(0x0, base_port + UART_IER);
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/* enable fifo's */
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outb(0x01, base_port + UART_FCR);
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/* assert DTR and RTS so the other end is happy */
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outb(0x03, base_port + UART_MCR);
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/* Set Baud Rate Divisor to 12 ==> 115200 Baud */
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outb(0x80 | lcs, base_port + UART_LCR);
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outb(divisor & 0xFF, base_port + UART_DLL);
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outb((divisor >> 8) & 0xFF, base_port + UART_DLM);
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outb(lcs, base_port + UART_LCR);
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}
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/* Initialize a generic uart */
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void init_uart8250(unsigned base_port, struct uart8250 *uart)
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{
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int divisor;
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int lcs;
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divisor = 115200/(uart->baud ? uart->baud: 1);
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lcs = 3;
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if (base_port == CONFIG_TTYS0_BASE) {
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/* Don't reinitialize the console serial port,
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* This is espeically nasty in SMP.
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*/
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return;
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}
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uart8250_init(base_port, divisor, lcs);
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}
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