diff options
Diffstat (limited to 'drivers/tty/serial/zs.c')
| -rw-r--r-- | drivers/tty/serial/zs.c | 1307 |
1 files changed, 1307 insertions, 0 deletions
diff --git a/drivers/tty/serial/zs.c b/drivers/tty/serial/zs.c new file mode 100644 index 000000000..4b4f60464 --- /dev/null +++ b/drivers/tty/serial/zs.c @@ -0,0 +1,1307 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * zs.c: Serial port driver for IOASIC DECstations. + * + * Derived from drivers/sbus/char/sunserial.c by Paul Mackerras. + * Derived from drivers/macintosh/macserial.c by Harald Koerfgen. + * + * DECstation changes + * Copyright (C) 1998-2000 Harald Koerfgen + * Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2007 Maciej W. Rozycki + * + * For the rest of the code the original Copyright applies: + * Copyright (C) 1996 Paul Mackerras (Paul.Mackerras@cs.anu.edu.au) + * Copyright (C) 1995 David S. Miller (davem@caip.rutgers.edu) + * + * + * Note: for IOASIC systems the wiring is as follows: + * + * mouse/keyboard: + * DIN-7 MJ-4 signal SCC + * 2 1 TxD <- A.TxD + * 3 4 RxD -> A.RxD + * + * EIA-232/EIA-423: + * DB-25 MMJ-6 signal SCC + * 2 2 TxD <- B.TxD + * 3 5 RxD -> B.RxD + * 4 RTS <- ~A.RTS + * 5 CTS -> ~B.CTS + * 6 6 DSR -> ~A.SYNC + * 8 CD -> ~B.DCD + * 12 DSRS(DCE) -> ~A.CTS (*) + * 15 TxC -> B.TxC + * 17 RxC -> B.RxC + * 20 1 DTR <- ~A.DTR + * 22 RI -> ~A.DCD + * 23 DSRS(DTE) <- ~B.RTS + * + * (*) EIA-232 defines the signal at this pin to be SCD, while DSRS(DCE) + * is shared with DSRS(DTE) at pin 23. + * + * As you can immediately notice the wiring of the RTS, DTR and DSR signals + * is a bit odd. This makes the handling of port B unnecessarily + * complicated and prevents the use of some automatic modes of operation. + */ + +#include <linux/bug.h> +#include <linux/console.h> +#include <linux/delay.h> +#include <linux/errno.h> +#include <linux/init.h> +#include <linux/interrupt.h> +#include <linux/io.h> +#include <linux/ioport.h> +#include <linux/irqflags.h> +#include <linux/kernel.h> +#include <linux/module.h> +#include <linux/major.h> +#include <linux/serial.h> +#include <linux/serial_core.h> +#include <linux/spinlock.h> +#include <linux/sysrq.h> +#include <linux/tty.h> +#include <linux/tty_flip.h> +#include <linux/types.h> + +#include <linux/atomic.h> + +#include <asm/dec/interrupts.h> +#include <asm/dec/ioasic_addrs.h> +#include <asm/dec/system.h> + +#include "zs.h" + + +MODULE_AUTHOR("Maciej W. Rozycki <macro@linux-mips.org>"); +MODULE_DESCRIPTION("DECstation Z85C30 serial driver"); +MODULE_LICENSE("GPL"); + + +static char zs_name[] __initdata = "DECstation Z85C30 serial driver version "; +static char zs_version[] __initdata = "0.10"; + +/* + * It would be nice to dynamically allocate everything that + * depends on ZS_NUM_SCCS, so we could support any number of + * Z85C30s, but for now... + */ +#define ZS_NUM_SCCS 2 /* Max # of ZS chips supported. */ +#define ZS_NUM_CHAN 2 /* 2 channels per chip. */ +#define ZS_CHAN_A 0 /* Index of the channel A. */ +#define ZS_CHAN_B 1 /* Index of the channel B. */ +#define ZS_CHAN_IO_SIZE 8 /* IOMEM space size. */ +#define ZS_CHAN_IO_STRIDE 4 /* Register alignment. */ +#define ZS_CHAN_IO_OFFSET 1 /* The SCC resides on the high byte + of the 16-bit IOBUS. */ +#define ZS_CLOCK 7372800 /* Z85C30 PCLK input clock rate. */ + +#define to_zport(uport) container_of(uport, struct zs_port, port) + +struct zs_parms { + resource_size_t scc[ZS_NUM_SCCS]; + int irq[ZS_NUM_SCCS]; +}; + +static struct zs_scc zs_sccs[ZS_NUM_SCCS]; + +static u8 zs_init_regs[ZS_NUM_REGS] __initdata = { + 0, /* write 0 */ + PAR_SPEC, /* write 1 */ + 0, /* write 2 */ + 0, /* write 3 */ + X16CLK | SB1, /* write 4 */ + 0, /* write 5 */ + 0, 0, 0, /* write 6, 7, 8 */ + MIE | DLC | NV, /* write 9 */ + NRZ, /* write 10 */ + TCBR | RCBR, /* write 11 */ + 0, 0, /* BRG time constant, write 12 + 13 */ + BRSRC | BRENABL, /* write 14 */ + 0, /* write 15 */ +}; + +/* + * Debugging. + */ +#undef ZS_DEBUG_REGS + + +/* + * Reading and writing Z85C30 registers. + */ +static void recovery_delay(void) +{ + udelay(2); +} + +static u8 read_zsreg(struct zs_port *zport, int reg) +{ + void __iomem *control = zport->port.membase + ZS_CHAN_IO_OFFSET; + u8 retval; + + if (reg != 0) { + writeb(reg & 0xf, control); + fast_iob(); + recovery_delay(); + } + retval = readb(control); + recovery_delay(); + return retval; +} + +static void write_zsreg(struct zs_port *zport, int reg, u8 value) +{ + void __iomem *control = zport->port.membase + ZS_CHAN_IO_OFFSET; + + if (reg != 0) { + writeb(reg & 0xf, control); + fast_iob(); recovery_delay(); + } + writeb(value, control); + fast_iob(); + recovery_delay(); + return; +} + +static u8 read_zsdata(struct zs_port *zport) +{ + void __iomem *data = zport->port.membase + + ZS_CHAN_IO_STRIDE + ZS_CHAN_IO_OFFSET; + u8 retval; + + retval = readb(data); + recovery_delay(); + return retval; +} + +static void write_zsdata(struct zs_port *zport, u8 value) +{ + void __iomem *data = zport->port.membase + + ZS_CHAN_IO_STRIDE + ZS_CHAN_IO_OFFSET; + + writeb(value, data); + fast_iob(); + recovery_delay(); + return; +} + +#ifdef ZS_DEBUG_REGS +void zs_dump(void) +{ + struct zs_port *zport; + int i, j; + + for (i = 0; i < ZS_NUM_SCCS * ZS_NUM_CHAN; i++) { + zport = &zs_sccs[i / ZS_NUM_CHAN].zport[i % ZS_NUM_CHAN]; + + if (!zport->scc) + continue; + + for (j = 0; j < 16; j++) + printk("W%-2d = 0x%02x\t", j, zport->regs[j]); + printk("\n"); + for (j = 0; j < 16; j++) + printk("R%-2d = 0x%02x\t", j, read_zsreg(zport, j)); + printk("\n\n"); + } +} +#endif + + +static void zs_spin_lock_cond_irq(spinlock_t *lock, int irq) +{ + if (irq) + spin_lock_irq(lock); + else + spin_lock(lock); +} + +static void zs_spin_unlock_cond_irq(spinlock_t *lock, int irq) +{ + if (irq) + spin_unlock_irq(lock); + else + spin_unlock(lock); +} + +static int zs_receive_drain(struct zs_port *zport) +{ + int loops = 10000; + + while ((read_zsreg(zport, R0) & Rx_CH_AV) && --loops) + read_zsdata(zport); + return loops; +} + +static int zs_transmit_drain(struct zs_port *zport, int irq) +{ + struct zs_scc *scc = zport->scc; + int loops = 10000; + + while (!(read_zsreg(zport, R0) & Tx_BUF_EMP) && --loops) { + zs_spin_unlock_cond_irq(&scc->zlock, irq); + udelay(2); + zs_spin_lock_cond_irq(&scc->zlock, irq); + } + return loops; +} + +static int zs_line_drain(struct zs_port *zport, int irq) +{ + struct zs_scc *scc = zport->scc; + int loops = 10000; + + while (!(read_zsreg(zport, R1) & ALL_SNT) && --loops) { + zs_spin_unlock_cond_irq(&scc->zlock, irq); + udelay(2); + zs_spin_lock_cond_irq(&scc->zlock, irq); + } + return loops; +} + + +static void load_zsregs(struct zs_port *zport, u8 *regs, int irq) +{ + /* Let the current transmission finish. */ + zs_line_drain(zport, irq); + /* Load 'em up. */ + write_zsreg(zport, R3, regs[3] & ~RxENABLE); + write_zsreg(zport, R5, regs[5] & ~TxENAB); + write_zsreg(zport, R4, regs[4]); + write_zsreg(zport, R9, regs[9]); + write_zsreg(zport, R1, regs[1]); + write_zsreg(zport, R2, regs[2]); + write_zsreg(zport, R10, regs[10]); + write_zsreg(zport, R14, regs[14] & ~BRENABL); + write_zsreg(zport, R11, regs[11]); + write_zsreg(zport, R12, regs[12]); + write_zsreg(zport, R13, regs[13]); + write_zsreg(zport, R14, regs[14]); + write_zsreg(zport, R15, regs[15]); + if (regs[3] & RxENABLE) + write_zsreg(zport, R3, regs[3]); + if (regs[5] & TxENAB) + write_zsreg(zport, R5, regs[5]); + return; +} + + +/* + * Status handling routines. + */ + +/* + * zs_tx_empty() -- get the transmitter empty status + * + * Purpose: Let user call ioctl() to get info when the UART physically + * is emptied. On bus types like RS485, the transmitter must + * release the bus after transmitting. This must be done when + * the transmit shift register is empty, not be done when the + * transmit holding register is empty. This functionality + * allows an RS485 driver to be written in user space. + */ +static unsigned int zs_tx_empty(struct uart_port *uport) +{ + struct zs_port *zport = to_zport(uport); + struct zs_scc *scc = zport->scc; + unsigned long flags; + u8 status; + + spin_lock_irqsave(&scc->zlock, flags); + status = read_zsreg(zport, R1); + spin_unlock_irqrestore(&scc->zlock, flags); + + return status & ALL_SNT ? TIOCSER_TEMT : 0; +} + +static unsigned int zs_raw_get_ab_mctrl(struct zs_port *zport_a, + struct zs_port *zport_b) +{ + u8 status_a, status_b; + unsigned int mctrl; + + status_a = read_zsreg(zport_a, R0); + status_b = read_zsreg(zport_b, R0); + + mctrl = ((status_b & CTS) ? TIOCM_CTS : 0) | + ((status_b & DCD) ? TIOCM_CAR : 0) | + ((status_a & DCD) ? TIOCM_RNG : 0) | + ((status_a & SYNC_HUNT) ? TIOCM_DSR : 0); + + return mctrl; +} + +static unsigned int zs_raw_get_mctrl(struct zs_port *zport) +{ + struct zs_port *zport_a = &zport->scc->zport[ZS_CHAN_A]; + + return zport != zport_a ? zs_raw_get_ab_mctrl(zport_a, zport) : 0; +} + +static unsigned int zs_raw_xor_mctrl(struct zs_port *zport) +{ + struct zs_port *zport_a = &zport->scc->zport[ZS_CHAN_A]; + unsigned int mmask, mctrl, delta; + u8 mask_a, mask_b; + + if (zport == zport_a) + return 0; + + mask_a = zport_a->regs[15]; + mask_b = zport->regs[15]; + + mmask = ((mask_b & CTSIE) ? TIOCM_CTS : 0) | + ((mask_b & DCDIE) ? TIOCM_CAR : 0) | + ((mask_a & DCDIE) ? TIOCM_RNG : 0) | + ((mask_a & SYNCIE) ? TIOCM_DSR : 0); + + mctrl = zport->mctrl; + if (mmask) { + mctrl &= ~mmask; + mctrl |= zs_raw_get_ab_mctrl(zport_a, zport) & mmask; + } + + delta = mctrl ^ zport->mctrl; + if (delta) + zport->mctrl = mctrl; + + return delta; +} + +static unsigned int zs_get_mctrl(struct uart_port *uport) +{ + struct zs_port *zport = to_zport(uport); + struct zs_scc *scc = zport->scc; + unsigned int mctrl; + + spin_lock(&scc->zlock); + mctrl = zs_raw_get_mctrl(zport); + spin_unlock(&scc->zlock); + + return mctrl; +} + +static void zs_set_mctrl(struct uart_port *uport, unsigned int mctrl) +{ + struct zs_port *zport = to_zport(uport); + struct zs_scc *scc = zport->scc; + struct zs_port *zport_a = &scc->zport[ZS_CHAN_A]; + u8 oldloop, newloop; + + spin_lock(&scc->zlock); + if (zport != zport_a) { + if (mctrl & TIOCM_DTR) + zport_a->regs[5] |= DTR; + else + zport_a->regs[5] &= ~DTR; + if (mctrl & TIOCM_RTS) + zport_a->regs[5] |= RTS; + else + zport_a->regs[5] &= ~RTS; + write_zsreg(zport_a, R5, zport_a->regs[5]); + } + + /* Rarely modified, so don't poke at hardware unless necessary. */ + oldloop = zport->regs[14]; + newloop = oldloop; + if (mctrl & TIOCM_LOOP) + newloop |= LOOPBAK; + else + newloop &= ~LOOPBAK; + if (newloop != oldloop) { + zport->regs[14] = newloop; + write_zsreg(zport, R14, zport->regs[14]); + } + spin_unlock(&scc->zlock); +} + +static void zs_raw_stop_tx(struct zs_port *zport) +{ + write_zsreg(zport, R0, RES_Tx_P); + zport->tx_stopped = 1; +} + +static void zs_stop_tx(struct uart_port *uport) +{ + struct zs_port *zport = to_zport(uport); + struct zs_scc *scc = zport->scc; + + spin_lock(&scc->zlock); + zs_raw_stop_tx(zport); + spin_unlock(&scc->zlock); +} + +static void zs_raw_transmit_chars(struct zs_port *); + +static void zs_start_tx(struct uart_port *uport) +{ + struct zs_port *zport = to_zport(uport); + struct zs_scc *scc = zport->scc; + + spin_lock(&scc->zlock); + if (zport->tx_stopped) { + zs_transmit_drain(zport, 0); + zport->tx_stopped = 0; + zs_raw_transmit_chars(zport); + } + spin_unlock(&scc->zlock); +} + +static void zs_stop_rx(struct uart_port *uport) +{ + struct zs_port *zport = to_zport(uport); + struct zs_scc *scc = zport->scc; + struct zs_port *zport_a = &scc->zport[ZS_CHAN_A]; + + spin_lock(&scc->zlock); + zport->regs[15] &= ~BRKIE; + zport->regs[1] &= ~(RxINT_MASK | TxINT_ENAB); + zport->regs[1] |= RxINT_DISAB; + + if (zport != zport_a) { + /* A-side DCD tracks RI and SYNC tracks DSR. */ + zport_a->regs[15] &= ~(DCDIE | SYNCIE); + write_zsreg(zport_a, R15, zport_a->regs[15]); + if (!(zport_a->regs[15] & BRKIE)) { + zport_a->regs[1] &= ~EXT_INT_ENAB; + write_zsreg(zport_a, R1, zport_a->regs[1]); + } + + /* This-side DCD tracks DCD and CTS tracks CTS. */ + zport->regs[15] &= ~(DCDIE | CTSIE); + zport->regs[1] &= ~EXT_INT_ENAB; + } else { + /* DCD tracks RI and SYNC tracks DSR for the B side. */ + if (!(zport->regs[15] & (DCDIE | SYNCIE))) + zport->regs[1] &= ~EXT_INT_ENAB; + } + + write_zsreg(zport, R15, zport->regs[15]); + write_zsreg(zport, R1, zport->regs[1]); + spin_unlock(&scc->zlock); +} + +static void zs_enable_ms(struct uart_port *uport) +{ + struct zs_port *zport = to_zport(uport); + struct zs_scc *scc = zport->scc; + struct zs_port *zport_a = &scc->zport[ZS_CHAN_A]; + + if (zport == zport_a) + return; + + spin_lock(&scc->zlock); + + /* Clear Ext interrupts if not being handled already. */ + if (!(zport_a->regs[1] & EXT_INT_ENAB)) + write_zsreg(zport_a, R0, RES_EXT_INT); + + /* A-side DCD tracks RI and SYNC tracks DSR. */ + zport_a->regs[1] |= EXT_INT_ENAB; + zport_a->regs[15] |= DCDIE | SYNCIE; + + /* This-side DCD tracks DCD and CTS tracks CTS. */ + zport->regs[15] |= DCDIE | CTSIE; + + zs_raw_xor_mctrl(zport); + + write_zsreg(zport_a, R1, zport_a->regs[1]); + write_zsreg(zport_a, R15, zport_a->regs[15]); + write_zsreg(zport, R15, zport->regs[15]); + spin_unlock(&scc->zlock); +} + +static void zs_break_ctl(struct uart_port *uport, int break_state) +{ + struct zs_port *zport = to_zport(uport); + struct zs_scc *scc = zport->scc; + unsigned long flags; + + spin_lock_irqsave(&scc->zlock, flags); + if (break_state == -1) + zport->regs[5] |= SND_BRK; + else + zport->regs[5] &= ~SND_BRK; + write_zsreg(zport, R5, zport->regs[5]); + spin_unlock_irqrestore(&scc->zlock, flags); +} + + +/* + * Interrupt handling routines. + */ +#define Rx_BRK 0x0100 /* BREAK event software flag. */ +#define Rx_SYS 0x0200 /* SysRq event software flag. */ + +static void zs_receive_chars(struct zs_port *zport) +{ + struct uart_port *uport = &zport->port; + struct zs_scc *scc = zport->scc; + struct uart_icount *icount; + unsigned int avail, status, ch, flag; + int count; + + for (count = 16; count; count--) { + spin_lock(&scc->zlock); + avail = read_zsreg(zport, R0) & Rx_CH_AV; + spin_unlock(&scc->zlock); + if (!avail) + break; + + spin_lock(&scc->zlock); + status = read_zsreg(zport, R1) & (Rx_OVR | FRM_ERR | PAR_ERR); + ch = read_zsdata(zport); + spin_unlock(&scc->zlock); + + flag = TTY_NORMAL; + + icount = &uport->icount; + icount->rx++; + + /* Handle the null char got when BREAK is removed. */ + if (!ch) + status |= zport->tty_break; + if (unlikely(status & + (Rx_OVR | FRM_ERR | PAR_ERR | Rx_SYS | Rx_BRK))) { + zport->tty_break = 0; + + /* Reset the error indication. */ + if (status & (Rx_OVR | FRM_ERR | PAR_ERR)) { + spin_lock(&scc->zlock); + write_zsreg(zport, R0, ERR_RES); + spin_unlock(&scc->zlock); + } + + if (status & (Rx_SYS | Rx_BRK)) { + icount->brk++; + /* SysRq discards the null char. */ + if (status & Rx_SYS) + continue; + } else if (status & FRM_ERR) + icount->frame++; + else if (status & PAR_ERR) + icount->parity++; + if (status & Rx_OVR) + icount->overrun++; + + status &= uport->read_status_mask; + if (status & Rx_BRK) + flag = TTY_BREAK; + else if (status & FRM_ERR) + flag = TTY_FRAME; + else if (status & PAR_ERR) + flag = TTY_PARITY; + } + + if (uart_handle_sysrq_char(uport, ch)) + continue; + + uart_insert_char(uport, status, Rx_OVR, ch, flag); + } + + tty_flip_buffer_push(&uport->state->port); +} + +static void zs_raw_transmit_chars(struct zs_port *zport) +{ + struct circ_buf *xmit = &zport->port.state->xmit; + + /* XON/XOFF chars. */ + if (zport->port.x_char) { + write_zsdata(zport, zport->port.x_char); + zport->port.icount.tx++; + zport->port.x_char = 0; + return; + } + + /* If nothing to do or stopped or hardware stopped. */ + if (uart_circ_empty(xmit) || uart_tx_stopped(&zport->port)) { + zs_raw_stop_tx(zport); + return; + } + + /* Send char. */ + write_zsdata(zport, xmit->buf[xmit->tail]); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + zport->port.icount.tx++; + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&zport->port); + + /* Are we are done? */ + if (uart_circ_empty(xmit)) + zs_raw_stop_tx(zport); +} + +static void zs_transmit_chars(struct zs_port *zport) +{ + struct zs_scc *scc = zport->scc; + + spin_lock(&scc->zlock); + zs_raw_transmit_chars(zport); + spin_unlock(&scc->zlock); +} + +static void zs_status_handle(struct zs_port *zport, struct zs_port *zport_a) +{ + struct uart_port *uport = &zport->port; + struct zs_scc *scc = zport->scc; + unsigned int delta; + u8 status, brk; + + spin_lock(&scc->zlock); + + /* Get status from Read Register 0. */ + status = read_zsreg(zport, R0); + + if (zport->regs[15] & BRKIE) { + brk = status & BRK_ABRT; + if (brk && !zport->brk) { + spin_unlock(&scc->zlock); + if (uart_handle_break(uport)) + zport->tty_break = Rx_SYS; + else + zport->tty_break = Rx_BRK; + spin_lock(&scc->zlock); + } + zport->brk = brk; + } + + if (zport != zport_a) { + delta = zs_raw_xor_mctrl(zport); + spin_unlock(&scc->zlock); + + if (delta & TIOCM_CTS) + uart_handle_cts_change(uport, + zport->mctrl & TIOCM_CTS); + if (delta & TIOCM_CAR) + uart_handle_dcd_change(uport, + zport->mctrl & TIOCM_CAR); + if (delta & TIOCM_RNG) + uport->icount.dsr++; + if (delta & TIOCM_DSR) + uport->icount.rng++; + + if (delta) + wake_up_interruptible(&uport->state->port.delta_msr_wait); + + spin_lock(&scc->zlock); + } + + /* Clear the status condition... */ + write_zsreg(zport, R0, RES_EXT_INT); + + spin_unlock(&scc->zlock); +} + +/* + * This is the Z85C30 driver's generic interrupt routine. + */ +static irqreturn_t zs_interrupt(int irq, void *dev_id) +{ + struct zs_scc *scc = dev_id; + struct zs_port *zport_a = &scc->zport[ZS_CHAN_A]; + struct zs_port *zport_b = &scc->zport[ZS_CHAN_B]; + irqreturn_t status = IRQ_NONE; + u8 zs_intreg; + int count; + + /* + * NOTE: The read register 3, which holds the irq status, + * does so for both channels on each chip. Although + * the status value itself must be read from the A + * channel and is only valid when read from channel A. + * Yes... broken hardware... + */ + for (count = 16; count; count--) { + spin_lock(&scc->zlock); + zs_intreg = read_zsreg(zport_a, R3); + spin_unlock(&scc->zlock); + if (!zs_intreg) + break; + + /* + * We do not like losing characters, so we prioritise + * interrupt sources a little bit differently than + * the SCC would, was it allowed to. + */ + if (zs_intreg & CHBRxIP) + zs_receive_chars(zport_b); + if (zs_intreg & CHARxIP) + zs_receive_chars(zport_a); + if (zs_intreg & CHBEXT) + zs_status_handle(zport_b, zport_a); + if (zs_intreg & CHAEXT) + zs_status_handle(zport_a, zport_a); + if (zs_intreg & CHBTxIP) + zs_transmit_chars(zport_b); + if (zs_intreg & CHATxIP) + zs_transmit_chars(zport_a); + + status = IRQ_HANDLED; + } + + return status; +} + + +/* + * Finally, routines used to initialize the serial port. + */ +static int zs_startup(struct uart_port *uport) +{ + struct zs_port *zport = to_zport(uport); + struct zs_scc *scc = zport->scc; + unsigned long flags; + int irq_guard; + int ret; + + irq_guard = atomic_add_return(1, &scc->irq_guard); + if (irq_guard == 1) { + ret = request_irq(zport->port.irq, zs_interrupt, + IRQF_SHARED, "scc", scc); + if (ret) { + atomic_add(-1, &scc->irq_guard); + printk(KERN_ERR "zs: can't get irq %d\n", + zport->port.irq); + return ret; + } + } + + spin_lock_irqsave(&scc->zlock, flags); + + /* Clear the receive FIFO. */ + zs_receive_drain(zport); + + /* Clear the interrupt registers. */ + write_zsreg(zport, R0, ERR_RES); + write_zsreg(zport, R0, RES_Tx_P); + /* But Ext only if not being handled already. */ + if (!(zport->regs[1] & EXT_INT_ENAB)) + write_zsreg(zport, R0, RES_EXT_INT); + + /* Finally, enable sequencing and interrupts. */ + zport->regs[1] &= ~RxINT_MASK; + zport->regs[1] |= RxINT_ALL | TxINT_ENAB | EXT_INT_ENAB; + zport->regs[3] |= RxENABLE; + zport->regs[15] |= BRKIE; + write_zsreg(zport, R1, zport->regs[1]); + write_zsreg(zport, R3, zport->regs[3]); + write_zsreg(zport, R5, zport->regs[5]); + write_zsreg(zport, R15, zport->regs[15]); + + /* Record the current state of RR0. */ + zport->mctrl = zs_raw_get_mctrl(zport); + zport->brk = read_zsreg(zport, R0) & BRK_ABRT; + + zport->tx_stopped = 1; + + spin_unlock_irqrestore(&scc->zlock, flags); + + return 0; +} + +static void zs_shutdown(struct uart_port *uport) +{ + struct zs_port *zport = to_zport(uport); + struct zs_scc *scc = zport->scc; + unsigned long flags; + int irq_guard; + + spin_lock_irqsave(&scc->zlock, flags); + + zport->regs[3] &= ~RxENABLE; + write_zsreg(zport, R5, zport->regs[5]); + write_zsreg(zport, R3, zport->regs[3]); + + spin_unlock_irqrestore(&scc->zlock, flags); + + irq_guard = atomic_add_return(-1, &scc->irq_guard); + if (!irq_guard) + free_irq(zport->port.irq, scc); +} + + +static void zs_reset(struct zs_port *zport) +{ + struct zs_scc *scc = zport->scc; + int irq; + unsigned long flags; + + spin_lock_irqsave(&scc->zlock, flags); + irq = !irqs_disabled_flags(flags); + if (!scc->initialised) { + /* Reset the pointer first, just in case... */ + read_zsreg(zport, R0); + /* And let the current transmission finish. */ + zs_line_drain(zport, irq); + write_zsreg(zport, R9, FHWRES); + udelay(10); + write_zsreg(zport, R9, 0); + scc->initialised = 1; + } + load_zsregs(zport, zport->regs, irq); + spin_unlock_irqrestore(&scc->zlock, flags); +} + +static void zs_set_termios(struct uart_port *uport, struct ktermios *termios, + struct ktermios *old_termios) +{ + struct zs_port *zport = to_zport(uport); + struct zs_scc *scc = zport->scc; + struct zs_port *zport_a = &scc->zport[ZS_CHAN_A]; + int irq; + unsigned int baud, brg; + unsigned long flags; + + spin_lock_irqsave(&scc->zlock, flags); + irq = !irqs_disabled_flags(flags); + + /* Byte size. */ + zport->regs[3] &= ~RxNBITS_MASK; + zport->regs[5] &= ~TxNBITS_MASK; + switch (termios->c_cflag & CSIZE) { + case CS5: + zport->regs[3] |= Rx5; + zport->regs[5] |= Tx5; + break; + case CS6: + zport->regs[3] |= Rx6; + zport->regs[5] |= Tx6; + break; + case CS7: + zport->regs[3] |= Rx7; + zport->regs[5] |= Tx7; + break; + case CS8: + default: + zport->regs[3] |= Rx8; + zport->regs[5] |= Tx8; + break; + } + + /* Parity and stop bits. */ + zport->regs[4] &= ~(XCLK_MASK | SB_MASK | PAR_ENA | PAR_EVEN); + if (termios->c_cflag & CSTOPB) + zport->regs[4] |= SB2; + else + zport->regs[4] |= SB1; + if (termios->c_cflag & PARENB) + zport->regs[4] |= PAR_ENA; + if (!(termios->c_cflag & PARODD)) + zport->regs[4] |= PAR_EVEN; + switch (zport->clk_mode) { + case 64: + zport->regs[4] |= X64CLK; + break; + case 32: + zport->regs[4] |= X32CLK; + break; + case 16: + zport->regs[4] |= X16CLK; + break; + case 1: + zport->regs[4] |= X1CLK; + break; + default: + BUG(); + } + + baud = uart_get_baud_rate(uport, termios, old_termios, 0, + uport->uartclk / zport->clk_mode / 4); + + brg = ZS_BPS_TO_BRG(baud, uport->uartclk / zport->clk_mode); + zport->regs[12] = brg & 0xff; + zport->regs[13] = (brg >> 8) & 0xff; + + uart_update_timeout(uport, termios->c_cflag, baud); + + uport->read_status_mask = Rx_OVR; + if (termios->c_iflag & INPCK) + uport->read_status_mask |= FRM_ERR | PAR_ERR; + if (termios->c_iflag & (IGNBRK | BRKINT | PARMRK)) + uport->read_status_mask |= Rx_BRK; + + uport->ignore_status_mask = 0; + if (termios->c_iflag & IGNPAR) + uport->ignore_status_mask |= FRM_ERR | PAR_ERR; + if (termios->c_iflag & IGNBRK) { + uport->ignore_status_mask |= Rx_BRK; + if (termios->c_iflag & IGNPAR) + uport->ignore_status_mask |= Rx_OVR; + } + + if (termios->c_cflag & CREAD) + zport->regs[3] |= RxENABLE; + else + zport->regs[3] &= ~RxENABLE; + + if (zport != zport_a) { + if (!(termios->c_cflag & CLOCAL)) { + zport->regs[15] |= DCDIE; + } else + zport->regs[15] &= ~DCDIE; + if (termios->c_cflag & CRTSCTS) { + zport->regs[15] |= CTSIE; + } else + zport->regs[15] &= ~CTSIE; + zs_raw_xor_mctrl(zport); + } + + /* Load up the new values. */ + load_zsregs(zport, zport->regs, irq); + + spin_unlock_irqrestore(&scc->zlock, flags); +} + +/* + * Hack alert! + * Required solely so that the initial PROM-based console + * works undisturbed in parallel with this one. + */ +static void zs_pm(struct uart_port *uport, unsigned int state, + unsigned int oldstate) +{ + struct zs_port *zport = to_zport(uport); + + if (state < 3) + zport->regs[5] |= TxENAB; + else + zport->regs[5] &= ~TxENAB; + write_zsreg(zport, R5, zport->regs[5]); +} + + +static const char *zs_type(struct uart_port *uport) +{ + return "Z85C30 SCC"; +} + +static void zs_release_port(struct uart_port *uport) +{ + iounmap(uport->membase); + uport->membase = 0; + release_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE); +} + +static int zs_map_port(struct uart_port *uport) +{ + if (!uport->membase) + uport->membase = ioremap(uport->mapbase, + ZS_CHAN_IO_SIZE); + if (!uport->membase) { + printk(KERN_ERR "zs: Cannot map MMIO\n"); + return -ENOMEM; + } + return 0; +} + +static int zs_request_port(struct uart_port *uport) +{ + int ret; + + if (!request_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE, "scc")) { + printk(KERN_ERR "zs: Unable to reserve MMIO resource\n"); + return -EBUSY; + } + ret = zs_map_port(uport); + if (ret) { + release_mem_region(uport->mapbase, ZS_CHAN_IO_SIZE); + return ret; + } + return 0; +} + +static void zs_config_port(struct uart_port *uport, int flags) +{ + struct zs_port *zport = to_zport(uport); + + if (flags & UART_CONFIG_TYPE) { + if (zs_request_port(uport)) + return; + + uport->type = PORT_ZS; + + zs_reset(zport); + } +} + +static int zs_verify_port(struct uart_port *uport, struct serial_struct *ser) +{ + struct zs_port *zport = to_zport(uport); + int ret = 0; + + if (ser->type != PORT_UNKNOWN && ser->type != PORT_ZS) + ret = -EINVAL; + if (ser->irq != uport->irq) + ret = -EINVAL; + if (ser->baud_base != uport->uartclk / zport->clk_mode / 4) + ret = -EINVAL; + return ret; +} + + +static const struct uart_ops zs_ops = { + .tx_empty = zs_tx_empty, + .set_mctrl = zs_set_mctrl, + .get_mctrl = zs_get_mctrl, + .stop_tx = zs_stop_tx, + .start_tx = zs_start_tx, + .stop_rx = zs_stop_rx, + .enable_ms = zs_enable_ms, + .break_ctl = zs_break_ctl, + .startup = zs_startup, + .shutdown = zs_shutdown, + .set_termios = zs_set_termios, + .pm = zs_pm, + .type = zs_type, + .release_port = zs_release_port, + .request_port = zs_request_port, + .config_port = zs_config_port, + .verify_port = zs_verify_port, +}; + +/* + * Initialize Z85C30 port structures. + */ +static int __init zs_probe_sccs(void) +{ + static int probed; + struct zs_parms zs_parms; + int chip, side, irq; + int n_chips = 0; + int i; + + if (probed) + return 0; + + irq = dec_interrupt[DEC_IRQ_SCC0]; + if (irq >= 0) { + zs_parms.scc[n_chips] = IOASIC_SCC0; + zs_parms.irq[n_chips] = dec_interrupt[DEC_IRQ_SCC0]; + n_chips++; + } + irq = dec_interrupt[DEC_IRQ_SCC1]; + if (irq >= 0) { + zs_parms.scc[n_chips] = IOASIC_SCC1; + zs_parms.irq[n_chips] = dec_interrupt[DEC_IRQ_SCC1]; + n_chips++; + } + if (!n_chips) + return -ENXIO; + + probed = 1; + + for (chip = 0; chip < n_chips; chip++) { + spin_lock_init(&zs_sccs[chip].zlock); + for (side = 0; side < ZS_NUM_CHAN; side++) { + struct zs_port *zport = &zs_sccs[chip].zport[side]; + struct uart_port *uport = &zport->port; + + zport->scc = &zs_sccs[chip]; + zport->clk_mode = 16; + + uport->has_sysrq = IS_ENABLED(CONFIG_SERIAL_ZS_CONSOLE); + uport->irq = zs_parms.irq[chip]; + uport->uartclk = ZS_CLOCK; + uport->fifosize = 1; + uport->iotype = UPIO_MEM; + uport->flags = UPF_BOOT_AUTOCONF; + uport->ops = &zs_ops; + uport->line = chip * ZS_NUM_CHAN + side; + uport->mapbase = dec_kn_slot_base + + zs_parms.scc[chip] + + (side ^ ZS_CHAN_B) * ZS_CHAN_IO_SIZE; + + for (i = 0; i < ZS_NUM_REGS; i++) + zport->regs[i] = zs_init_regs[i]; + } + } + + return 0; +} + + +#ifdef CONFIG_SERIAL_ZS_CONSOLE +static void zs_console_putchar(struct uart_port *uport, int ch) +{ + struct zs_port *zport = to_zport(uport); + struct zs_scc *scc = zport->scc; + int irq; + unsigned long flags; + + spin_lock_irqsave(&scc->zlock, flags); + irq = !irqs_disabled_flags(flags); + if (zs_transmit_drain(zport, irq)) + write_zsdata(zport, ch); + spin_unlock_irqrestore(&scc->zlock, flags); +} + +/* + * Print a string to the serial port trying not to disturb + * any possible real use of the port... + */ +static void zs_console_write(struct console *co, const char *s, + unsigned int count) +{ + int chip = co->index / ZS_NUM_CHAN, side = co->index % ZS_NUM_CHAN; + struct zs_port *zport = &zs_sccs[chip].zport[side]; + struct zs_scc *scc = zport->scc; + unsigned long flags; + u8 txint, txenb; + int irq; + + /* Disable transmit interrupts and enable the transmitter. */ + spin_lock_irqsave(&scc->zlock, flags); + txint = zport->regs[1]; + txenb = zport->regs[5]; + if (txint & TxINT_ENAB) { + zport->regs[1] = txint & ~TxINT_ENAB; + write_zsreg(zport, R1, zport->regs[1]); + } + if (!(txenb & TxENAB)) { + zport->regs[5] = txenb | TxENAB; + write_zsreg(zport, R5, zport->regs[5]); + } + spin_unlock_irqrestore(&scc->zlock, flags); + + uart_console_write(&zport->port, s, count, zs_console_putchar); + + /* Restore transmit interrupts and the transmitter enable. */ + spin_lock_irqsave(&scc->zlock, flags); + irq = !irqs_disabled_flags(flags); + zs_line_drain(zport, irq); + if (!(txenb & TxENAB)) { + zport->regs[5] &= ~TxENAB; + write_zsreg(zport, R5, zport->regs[5]); + } + if (txint & TxINT_ENAB) { + zport->regs[1] |= TxINT_ENAB; + write_zsreg(zport, R1, zport->regs[1]); + + /* Resume any transmission as the TxIP bit won't be set. */ + if (!zport->tx_stopped) + zs_raw_transmit_chars(zport); + } + spin_unlock_irqrestore(&scc->zlock, flags); +} + +/* + * Setup serial console baud/bits/parity. We do two things here: + * - construct a cflag setting for the first uart_open() + * - initialise the serial port + * Return non-zero if we didn't find a serial port. + */ +static int __init zs_console_setup(struct console *co, char *options) +{ + int chip = co->index / ZS_NUM_CHAN, side = co->index % ZS_NUM_CHAN; + struct zs_port *zport = &zs_sccs[chip].zport[side]; + struct uart_port *uport = &zport->port; + int baud = 9600; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + int ret; + + ret = zs_map_port(uport); + if (ret) + return ret; + + zs_reset(zport); + zs_pm(uport, 0, -1); + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + return uart_set_options(uport, co, baud, parity, bits, flow); +} + +static struct uart_driver zs_reg; +static struct console zs_console = { + .name = "ttyS", + .write = zs_console_write, + .device = uart_console_device, + .setup = zs_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &zs_reg, +}; + +/* + * Register console. + */ +static int __init zs_serial_console_init(void) +{ + int ret; + + ret = zs_probe_sccs(); + if (ret) + return ret; + register_console(&zs_console); + + return 0; +} + +console_initcall(zs_serial_console_init); + +#define SERIAL_ZS_CONSOLE &zs_console +#else +#define SERIAL_ZS_CONSOLE NULL +#endif /* CONFIG_SERIAL_ZS_CONSOLE */ + +static struct uart_driver zs_reg = { + .owner = THIS_MODULE, + .driver_name = "serial", + .dev_name = "ttyS", + .major = TTY_MAJOR, + .minor = 64, + .nr = ZS_NUM_SCCS * ZS_NUM_CHAN, + .cons = SERIAL_ZS_CONSOLE, +}; + +/* zs_init inits the driver. */ +static int __init zs_init(void) +{ + int i, ret; + + pr_info("%s%s\n", zs_name, zs_version); + + /* Find out how many Z85C30 SCCs we have. */ + ret = zs_probe_sccs(); + if (ret) + return ret; + + ret = uart_register_driver(&zs_reg); + if (ret) + return ret; + + for (i = 0; i < ZS_NUM_SCCS * ZS_NUM_CHAN; i++) { + struct zs_scc *scc = &zs_sccs[i / ZS_NUM_CHAN]; + struct zs_port *zport = &scc->zport[i % ZS_NUM_CHAN]; + struct uart_port *uport = &zport->port; + + if (zport->scc) + uart_add_one_port(&zs_reg, uport); + } + + return 0; +} + +static void __exit zs_exit(void) +{ + int i; + + for (i = ZS_NUM_SCCS * ZS_NUM_CHAN - 1; i >= 0; i--) { + struct zs_scc *scc = &zs_sccs[i / ZS_NUM_CHAN]; + struct zs_port *zport = &scc->zport[i % ZS_NUM_CHAN]; + struct uart_port *uport = &zport->port; + + if (zport->scc) + uart_remove_one_port(&zs_reg, uport); + } + + uart_unregister_driver(&zs_reg); +} + +module_init(zs_init); +module_exit(zs_exit); |