diff options
Diffstat (limited to 'arch/ppc/boot/common/ns16550.c')
-rw-r--r-- | arch/ppc/boot/common/ns16550.c | 99 |
1 files changed, 99 insertions, 0 deletions
diff --git a/arch/ppc/boot/common/ns16550.c b/arch/ppc/boot/common/ns16550.c new file mode 100644 index 00000000000..9017c547a6f --- /dev/null +++ b/arch/ppc/boot/common/ns16550.c @@ -0,0 +1,99 @@ +/* + * COM1 NS16550 support + */ + +#include <linux/config.h> +#include <linux/types.h> +#include <linux/serial.h> +#include <linux/serial_reg.h> +#include <asm/serial.h> + +#include "nonstdio.h" +#include "serial.h" + +#define SERIAL_BAUD 9600 + +extern unsigned long ISA_io; + +static struct serial_state rs_table[RS_TABLE_SIZE] = { + SERIAL_PORT_DFNS /* Defined in <asm/serial.h> */ +}; + +static int shift; + +unsigned long serial_init(int chan, void *ignored) +{ + unsigned long com_port; + unsigned char lcr, dlm; + + /* We need to find out which type io we're expecting. If it's + * 'SERIAL_IO_PORT', we get an offset from the isa_io_base. + * If it's 'SERIAL_IO_MEM', we can the exact location. -- Tom */ + switch (rs_table[chan].io_type) { + case SERIAL_IO_PORT: + com_port = rs_table[chan].port; + break; + case SERIAL_IO_MEM: + com_port = (unsigned long)rs_table[chan].iomem_base; + break; + default: + /* We can't deal with it. */ + return -1; + } + + /* How far apart the registers are. */ + shift = rs_table[chan].iomem_reg_shift; + + /* save the LCR */ + lcr = inb(com_port + (UART_LCR << shift)); + /* Access baud rate */ + outb(com_port + (UART_LCR << shift), 0x80); + dlm = inb(com_port + (UART_DLM << shift)); + /* + * Test if serial port is unconfigured. + * We assume that no-one uses less than 110 baud or + * less than 7 bits per character these days. + * -- paulus. + */ + + if ((dlm <= 4) && (lcr & 2)) + /* port is configured, put the old LCR back */ + outb(com_port + (UART_LCR << shift), lcr); + else { + /* Input clock. */ + outb(com_port + (UART_DLL << shift), + (BASE_BAUD / SERIAL_BAUD) & 0xFF); + outb(com_port + (UART_DLM << shift), + (BASE_BAUD / SERIAL_BAUD) >> 8); + /* 8 data, 1 stop, no parity */ + outb(com_port + (UART_LCR << shift), 0x03); + /* RTS/DTR */ + outb(com_port + (UART_MCR << shift), 0x03); + } + /* Clear & enable FIFOs */ + outb(com_port + (UART_FCR << shift), 0x07); + + return (com_port); +} + +void +serial_putc(unsigned long com_port, unsigned char c) +{ + while ((inb(com_port + (UART_LSR << shift)) & UART_LSR_THRE) == 0) + ; + outb(com_port, c); +} + +unsigned char +serial_getc(unsigned long com_port) +{ + while ((inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) == 0) + ; + return inb(com_port); +} + +int +serial_tstc(unsigned long com_port) +{ + return ((inb(com_port + (UART_LSR << shift)) & UART_LSR_DR) != 0); +} |