diff options
Diffstat (limited to 'drivers/tty/serial')
119 files changed, 97162 insertions, 0 deletions
diff --git a/drivers/tty/serial/21285.c b/drivers/tty/serial/21285.c new file mode 100644 index 000000000000..d89aa38c5cf0 --- /dev/null +++ b/drivers/tty/serial/21285.c @@ -0,0 +1,513 @@ +/* + * linux/drivers/serial/21285.c + * + * Driver for the serial port on the 21285 StrongArm-110 core logic chip. + * + * Based on drivers/char/serial.c + */ +#include <linux/module.h> +#include <linux/tty.h> +#include <linux/ioport.h> +#include <linux/init.h> +#include <linux/console.h> +#include <linux/device.h> +#include <linux/tty_flip.h> +#include <linux/serial_core.h> +#include <linux/serial.h> +#include <linux/io.h> + +#include <asm/irq.h> +#include <asm/mach-types.h> +#include <asm/hardware/dec21285.h> +#include <mach/hardware.h> + +#define BAUD_BASE (mem_fclk_21285/64) + +#define SERIAL_21285_NAME "ttyFB" +#define SERIAL_21285_MAJOR 204 +#define SERIAL_21285_MINOR 4 + +#define RXSTAT_DUMMY_READ 0x80000000 +#define RXSTAT_FRAME (1 << 0) +#define RXSTAT_PARITY (1 << 1) +#define RXSTAT_OVERRUN (1 << 2) +#define RXSTAT_ANYERR (RXSTAT_FRAME|RXSTAT_PARITY|RXSTAT_OVERRUN) + +#define H_UBRLCR_BREAK (1 << 0) +#define H_UBRLCR_PARENB (1 << 1) +#define H_UBRLCR_PAREVN (1 << 2) +#define H_UBRLCR_STOPB (1 << 3) +#define H_UBRLCR_FIFO (1 << 4) + +static const char serial21285_name[] = "Footbridge UART"; + +#define tx_enabled(port) ((port)->unused[0]) +#define rx_enabled(port) ((port)->unused[1]) + +/* + * The documented expression for selecting the divisor is: + * BAUD_BASE / baud - 1 + * However, typically BAUD_BASE is not divisible by baud, so + * we want to select the divisor that gives us the minimum + * error. Therefore, we want: + * int(BAUD_BASE / baud - 0.5) -> + * int(BAUD_BASE / baud - (baud >> 1) / baud) -> + * int((BAUD_BASE - (baud >> 1)) / baud) + */ + +static void serial21285_stop_tx(struct uart_port *port) +{ + if (tx_enabled(port)) { + disable_irq_nosync(IRQ_CONTX); + tx_enabled(port) = 0; + } +} + +static void serial21285_start_tx(struct uart_port *port) +{ + if (!tx_enabled(port)) { + enable_irq(IRQ_CONTX); + tx_enabled(port) = 1; + } +} + +static void serial21285_stop_rx(struct uart_port *port) +{ + if (rx_enabled(port)) { + disable_irq_nosync(IRQ_CONRX); + rx_enabled(port) = 0; + } +} + +static void serial21285_enable_ms(struct uart_port *port) +{ +} + +static irqreturn_t serial21285_rx_chars(int irq, void *dev_id) +{ + struct uart_port *port = dev_id; + struct tty_struct *tty = port->state->port.tty; + unsigned int status, ch, flag, rxs, max_count = 256; + + status = *CSR_UARTFLG; + while (!(status & 0x10) && max_count--) { + ch = *CSR_UARTDR; + flag = TTY_NORMAL; + port->icount.rx++; + + rxs = *CSR_RXSTAT | RXSTAT_DUMMY_READ; + if (unlikely(rxs & RXSTAT_ANYERR)) { + if (rxs & RXSTAT_PARITY) + port->icount.parity++; + else if (rxs & RXSTAT_FRAME) + port->icount.frame++; + if (rxs & RXSTAT_OVERRUN) + port->icount.overrun++; + + rxs &= port->read_status_mask; + + if (rxs & RXSTAT_PARITY) + flag = TTY_PARITY; + else if (rxs & RXSTAT_FRAME) + flag = TTY_FRAME; + } + + uart_insert_char(port, rxs, RXSTAT_OVERRUN, ch, flag); + + status = *CSR_UARTFLG; + } + tty_flip_buffer_push(tty); + + return IRQ_HANDLED; +} + +static irqreturn_t serial21285_tx_chars(int irq, void *dev_id) +{ + struct uart_port *port = dev_id; + struct circ_buf *xmit = &port->state->xmit; + int count = 256; + + if (port->x_char) { + *CSR_UARTDR = port->x_char; + port->icount.tx++; + port->x_char = 0; + goto out; + } + if (uart_circ_empty(xmit) || uart_tx_stopped(port)) { + serial21285_stop_tx(port); + goto out; + } + + do { + *CSR_UARTDR = xmit->buf[xmit->tail]; + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + if (uart_circ_empty(xmit)) + break; + } while (--count > 0 && !(*CSR_UARTFLG & 0x20)); + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(port); + + if (uart_circ_empty(xmit)) + serial21285_stop_tx(port); + + out: + return IRQ_HANDLED; +} + +static unsigned int serial21285_tx_empty(struct uart_port *port) +{ + return (*CSR_UARTFLG & 8) ? 0 : TIOCSER_TEMT; +} + +/* no modem control lines */ +static unsigned int serial21285_get_mctrl(struct uart_port *port) +{ + return TIOCM_CAR | TIOCM_DSR | TIOCM_CTS; +} + +static void serial21285_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ +} + +static void serial21285_break_ctl(struct uart_port *port, int break_state) +{ + unsigned long flags; + unsigned int h_lcr; + + spin_lock_irqsave(&port->lock, flags); + h_lcr = *CSR_H_UBRLCR; + if (break_state) + h_lcr |= H_UBRLCR_BREAK; + else + h_lcr &= ~H_UBRLCR_BREAK; + *CSR_H_UBRLCR = h_lcr; + spin_unlock_irqrestore(&port->lock, flags); +} + +static int serial21285_startup(struct uart_port *port) +{ + int ret; + + tx_enabled(port) = 1; + rx_enabled(port) = 1; + + ret = request_irq(IRQ_CONRX, serial21285_rx_chars, 0, + serial21285_name, port); + if (ret == 0) { + ret = request_irq(IRQ_CONTX, serial21285_tx_chars, 0, + serial21285_name, port); + if (ret) + free_irq(IRQ_CONRX, port); + } + + return ret; +} + +static void serial21285_shutdown(struct uart_port *port) +{ + free_irq(IRQ_CONTX, port); + free_irq(IRQ_CONRX, port); +} + +static void +serial21285_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + unsigned long flags; + unsigned int baud, quot, h_lcr, b; + < |