diff options
Diffstat (limited to 'drivers/tty/serial/pmac_zilog.c')
| -rw-r--r-- | drivers/tty/serial/pmac_zilog.c | 2058 |
1 files changed, 2058 insertions, 0 deletions
diff --git a/drivers/tty/serial/pmac_zilog.c b/drivers/tty/serial/pmac_zilog.c new file mode 100644 index 000000000..d6aef8a1f --- /dev/null +++ b/drivers/tty/serial/pmac_zilog.c @@ -0,0 +1,2058 @@ +// SPDX-License-Identifier: GPL-2.0+ +/* + * Driver for PowerMac Z85c30 based ESCC cell found in the + * "macio" ASICs of various PowerMac models + * + * Copyright (C) 2003 Ben. Herrenschmidt (benh@kernel.crashing.org) + * + * Derived from drivers/macintosh/macserial.c by Paul Mackerras + * and drivers/serial/sunzilog.c by David S. Miller + * + * Hrm... actually, I ripped most of sunzilog (Thanks David !) and + * adapted special tweaks needed for us. I don't think it's worth + * merging back those though. The DMA code still has to get in + * and once done, I expect that driver to remain fairly stable in + * the long term, unless we change the driver model again... + * + * 2004-08-06 Harald Welte <laforge@gnumonks.org> + * - Enable BREAK interrupt + * - Add support for sysreq + * + * TODO: - Add DMA support + * - Defer port shutdown to a few seconds after close + * - maybe put something right into uap->clk_divisor + */ + +#undef DEBUG +#undef DEBUG_HARD +#undef USE_CTRL_O_SYSRQ + +#include <linux/module.h> +#include <linux/tty.h> + +#include <linux/tty_flip.h> +#include <linux/major.h> +#include <linux/string.h> +#include <linux/fcntl.h> +#include <linux/mm.h> +#include <linux/kernel.h> +#include <linux/delay.h> +#include <linux/init.h> +#include <linux/console.h> +#include <linux/adb.h> +#include <linux/pmu.h> +#include <linux/bitops.h> +#include <linux/sysrq.h> +#include <linux/mutex.h> +#include <linux/of_address.h> +#include <linux/of_irq.h> +#include <asm/sections.h> +#include <asm/io.h> +#include <asm/irq.h> + +#ifdef CONFIG_PPC_PMAC +#include <asm/prom.h> +#include <asm/machdep.h> +#include <asm/pmac_feature.h> +#include <asm/dbdma.h> +#include <asm/macio.h> +#else +#include <linux/platform_device.h> +#define of_machine_is_compatible(x) (0) +#endif + +#include <linux/serial.h> +#include <linux/serial_core.h> + +#include "pmac_zilog.h" + +/* Not yet implemented */ +#undef HAS_DBDMA + +static char version[] __initdata = "pmac_zilog: 0.6 (Benjamin Herrenschmidt <benh@kernel.crashing.org>)"; +MODULE_AUTHOR("Benjamin Herrenschmidt <benh@kernel.crashing.org>"); +MODULE_DESCRIPTION("Driver for the Mac and PowerMac serial ports."); +MODULE_LICENSE("GPL"); + +#ifdef CONFIG_SERIAL_PMACZILOG_TTYS +#define PMACZILOG_MAJOR TTY_MAJOR +#define PMACZILOG_MINOR 64 +#define PMACZILOG_NAME "ttyS" +#else +#define PMACZILOG_MAJOR 204 +#define PMACZILOG_MINOR 192 +#define PMACZILOG_NAME "ttyPZ" +#endif + +#define pmz_debug(fmt, arg...) pr_debug("ttyPZ%d: " fmt, uap->port.line, ## arg) +#define pmz_error(fmt, arg...) pr_err("ttyPZ%d: " fmt, uap->port.line, ## arg) +#define pmz_info(fmt, arg...) pr_info("ttyPZ%d: " fmt, uap->port.line, ## arg) + +/* + * For the sake of early serial console, we can do a pre-probe + * (optional) of the ports at rather early boot time. + */ +static struct uart_pmac_port pmz_ports[MAX_ZS_PORTS]; +static int pmz_ports_count; + +static struct uart_driver pmz_uart_reg = { + .owner = THIS_MODULE, + .driver_name = PMACZILOG_NAME, + .dev_name = PMACZILOG_NAME, + .major = PMACZILOG_MAJOR, + .minor = PMACZILOG_MINOR, +}; + + +/* + * Load all registers to reprogram the port + * This function must only be called when the TX is not busy. The UART + * port lock must be held and local interrupts disabled. + */ +static void pmz_load_zsregs(struct uart_pmac_port *uap, u8 *regs) +{ + int i; + + /* Let pending transmits finish. */ + for (i = 0; i < 1000; i++) { + unsigned char stat = read_zsreg(uap, R1); + if (stat & ALL_SNT) + break; + udelay(100); + } + + ZS_CLEARERR(uap); + zssync(uap); + ZS_CLEARFIFO(uap); + zssync(uap); + ZS_CLEARERR(uap); + + /* Disable all interrupts. */ + write_zsreg(uap, R1, + regs[R1] & ~(RxINT_MASK | TxINT_ENAB | EXT_INT_ENAB)); + + /* Set parity, sync config, stop bits, and clock divisor. */ + write_zsreg(uap, R4, regs[R4]); + + /* Set misc. TX/RX control bits. */ + write_zsreg(uap, R10, regs[R10]); + + /* Set TX/RX controls sans the enable bits. */ + write_zsreg(uap, R3, regs[R3] & ~RxENABLE); + write_zsreg(uap, R5, regs[R5] & ~TxENABLE); + + /* now set R7 "prime" on ESCC */ + write_zsreg(uap, R15, regs[R15] | EN85C30); + write_zsreg(uap, R7, regs[R7P]); + + /* make sure we use R7 "non-prime" on ESCC */ + write_zsreg(uap, R15, regs[R15] & ~EN85C30); + + /* Synchronous mode config. */ + write_zsreg(uap, R6, regs[R6]); + write_zsreg(uap, R7, regs[R7]); + + /* Disable baud generator. */ + write_zsreg(uap, R14, regs[R14] & ~BRENAB); + + /* Clock mode control. */ + write_zsreg(uap, R11, regs[R11]); + + /* Lower and upper byte of baud rate generator divisor. */ + write_zsreg(uap, R12, regs[R12]); + write_zsreg(uap, R13, regs[R13]); + + /* Now rewrite R14, with BRENAB (if set). */ + write_zsreg(uap, R14, regs[R14]); + + /* Reset external status interrupts. */ + write_zsreg(uap, R0, RES_EXT_INT); + write_zsreg(uap, R0, RES_EXT_INT); + + /* Rewrite R3/R5, this time without enables masked. */ + write_zsreg(uap, R3, regs[R3]); + write_zsreg(uap, R5, regs[R5]); + + /* Rewrite R1, this time without IRQ enabled masked. */ + write_zsreg(uap, R1, regs[R1]); + + /* Enable interrupts */ + write_zsreg(uap, R9, regs[R9]); +} + +/* + * We do like sunzilog to avoid disrupting pending Tx + * Reprogram the Zilog channel HW registers with the copies found in the + * software state struct. If the transmitter is busy, we defer this update + * until the next TX complete interrupt. Else, we do it right now. + * + * The UART port lock must be held and local interrupts disabled. + */ +static void pmz_maybe_update_regs(struct uart_pmac_port *uap) +{ + if (!ZS_REGS_HELD(uap)) { + if (ZS_TX_ACTIVE(uap)) { + uap->flags |= PMACZILOG_FLAG_REGS_HELD; + } else { + pmz_debug("pmz: maybe_update_regs: updating\n"); + pmz_load_zsregs(uap, uap->curregs); + } + } +} + +static void pmz_interrupt_control(struct uart_pmac_port *uap, int enable) +{ + if (enable) { + uap->curregs[1] |= INT_ALL_Rx | TxINT_ENAB; + if (!ZS_IS_EXTCLK(uap)) + uap->curregs[1] |= EXT_INT_ENAB; + } else { + uap->curregs[1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK); + } + write_zsreg(uap, R1, uap->curregs[1]); +} + +static bool pmz_receive_chars(struct uart_pmac_port *uap) + __must_hold(&uap->port.lock) +{ + struct tty_port *port; + unsigned char ch, r1, drop, flag; + int loops = 0; + + /* Sanity check, make sure the old bug is no longer happening */ + if (uap->port.state == NULL) { + WARN_ON(1); + (void)read_zsdata(uap); + return false; + } + port = &uap->port.state->port; + + while (1) { + drop = 0; + + r1 = read_zsreg(uap, R1); + ch = read_zsdata(uap); + + if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR)) { + write_zsreg(uap, R0, ERR_RES); + zssync(uap); + } + + ch &= uap->parity_mask; + if (ch == 0 && uap->flags & PMACZILOG_FLAG_BREAK) { + uap->flags &= ~PMACZILOG_FLAG_BREAK; + } + +#if defined(CONFIG_MAGIC_SYSRQ) && defined(CONFIG_SERIAL_CORE_CONSOLE) +#ifdef USE_CTRL_O_SYSRQ + /* Handle the SysRq ^O Hack */ + if (ch == '\x0f') { + uap->port.sysrq = jiffies + HZ*5; + goto next_char; + } +#endif /* USE_CTRL_O_SYSRQ */ + if (uap->port.sysrq) { + int swallow; + spin_unlock(&uap->port.lock); + swallow = uart_handle_sysrq_char(&uap->port, ch); + spin_lock(&uap->port.lock); + if (swallow) + goto next_char; + } +#endif /* CONFIG_MAGIC_SYSRQ && CONFIG_SERIAL_CORE_CONSOLE */ + + /* A real serial line, record the character and status. */ + if (drop) + goto next_char; + + flag = TTY_NORMAL; + uap->port.icount.rx++; + + if (r1 & (PAR_ERR | Rx_OVR | CRC_ERR | BRK_ABRT)) { + if (r1 & BRK_ABRT) { + pmz_debug("pmz: got break !\n"); + r1 &= ~(PAR_ERR | CRC_ERR); + uap->port.icount.brk++; + if (uart_handle_break(&uap->port)) + goto next_char; + } + else if (r1 & PAR_ERR) + uap->port.icount.parity++; + else if (r1 & CRC_ERR) + uap->port.icount.frame++; + if (r1 & Rx_OVR) + uap->port.icount.overrun++; + r1 &= uap->port.read_status_mask; + if (r1 & BRK_ABRT) + flag = TTY_BREAK; + else if (r1 & PAR_ERR) + flag = TTY_PARITY; + else if (r1 & CRC_ERR) + flag = TTY_FRAME; + } + + if (uap->port.ignore_status_mask == 0xff || + (r1 & uap->port.ignore_status_mask) == 0) { + tty_insert_flip_char(port, ch, flag); + } + if (r1 & Rx_OVR) + tty_insert_flip_char(port, 0, TTY_OVERRUN); + next_char: + /* We can get stuck in an infinite loop getting char 0 when the + * line is in a wrong HW state, we break that here. + * When that happens, I disable the receive side of the driver. + * Note that what I've been experiencing is a real irq loop where + * I'm getting flooded regardless of the actual port speed. + * Something strange is going on with the HW + */ + if ((++loops) > 1000) + goto flood; + ch = read_zsreg(uap, R0); + if (!(ch & Rx_CH_AV)) + break; + } + + return true; + flood: + pmz_interrupt_control(uap, 0); + pmz_error("pmz: rx irq flood !\n"); + return true; +} + +static void pmz_status_handle(struct uart_pmac_port *uap) +{ + unsigned char status; + + status = read_zsreg(uap, R0); + write_zsreg(uap, R0, RES_EXT_INT); + zssync(uap); + + if (ZS_IS_OPEN(uap) && ZS_WANTS_MODEM_STATUS(uap)) { + if (status & SYNC_HUNT) + uap->port.icount.dsr++; + + /* The Zilog just gives us an interrupt when DCD/CTS/etc. change. + * But it does not tell us which bit has changed, we have to keep + * track of this ourselves. + * The CTS input is inverted for some reason. -- paulus + */ + if ((status ^ uap->prev_status) & DCD) + uart_handle_dcd_change(&uap->port, + (status & DCD)); + if ((status ^ uap->prev_status) & CTS) + uart_handle_cts_change(&uap->port, + !(status & CTS)); + + wake_up_interruptible(&uap->port.state->port.delta_msr_wait); + } + + if (status & BRK_ABRT) + uap->flags |= PMACZILOG_FLAG_BREAK; + + uap->prev_status = status; +} + +static void pmz_transmit_chars(struct uart_pmac_port *uap) +{ + struct circ_buf *xmit; + + if (ZS_IS_CONS(uap)) { + unsigned char status = read_zsreg(uap, R0); + + /* TX still busy? Just wait for the next TX done interrupt. + * + * It can occur because of how we do serial console writes. It would + * be nice to transmit console writes just like we normally would for + * a TTY line. (ie. buffered and TX interrupt driven). That is not + * easy because console writes cannot sleep. One solution might be + * to poll on enough port->xmit space becoming free. -DaveM + */ + if (!(status & Tx_BUF_EMP)) + return; + } + + uap->flags &= ~PMACZILOG_FLAG_TX_ACTIVE; + + if (ZS_REGS_HELD(uap)) { + pmz_load_zsregs(uap, uap->curregs); + uap->flags &= ~PMACZILOG_FLAG_REGS_HELD; + } + + if (ZS_TX_STOPPED(uap)) { + uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED; + goto ack_tx_int; + } + + /* Under some circumstances, we see interrupts reported for + * a closed channel. The interrupt mask in R1 is clear, but + * R3 still signals the interrupts and we see them when taking + * an interrupt for the other channel (this could be a qemu + * bug but since the ESCC doc doesn't specify precsiely whether + * R3 interrup status bits are masked by R1 interrupt enable + * bits, better safe than sorry). --BenH. + */ + if (!ZS_IS_OPEN(uap)) + goto ack_tx_int; + + if (uap->port.x_char) { + uap->flags |= PMACZILOG_FLAG_TX_ACTIVE; + write_zsdata(uap, uap->port.x_char); + zssync(uap); + uap->port.icount.tx++; + uap->port.x_char = 0; + return; + } + + if (uap->port.state == NULL) + goto ack_tx_int; + xmit = &uap->port.state->xmit; + if (uart_circ_empty(xmit)) { + uart_write_wakeup(&uap->port); + goto ack_tx_int; + } + if (uart_tx_stopped(&uap->port)) + goto ack_tx_int; + + uap->flags |= PMACZILOG_FLAG_TX_ACTIVE; + write_zsdata(uap, xmit->buf[xmit->tail]); + zssync(uap); + + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + uap->port.icount.tx++; + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&uap->port); + + return; + +ack_tx_int: + write_zsreg(uap, R0, RES_Tx_P); + zssync(uap); +} + +/* Hrm... we register that twice, fixme later.... */ +static irqreturn_t pmz_interrupt(int irq, void *dev_id) +{ + struct uart_pmac_port *uap = dev_id; + struct uart_pmac_port *uap_a; + struct uart_pmac_port *uap_b; + int rc = IRQ_NONE; + bool push; + u8 r3; + + uap_a = pmz_get_port_A(uap); + uap_b = uap_a->mate; + + spin_lock(&uap_a->port.lock); + r3 = read_zsreg(uap_a, R3); + +#ifdef DEBUG_HARD + pmz_debug("irq, r3: %x\n", r3); +#endif + /* Channel A */ + push = false; + if (r3 & (CHAEXT | CHATxIP | CHARxIP)) { + if (!ZS_IS_OPEN(uap_a)) { + pmz_debug("ChanA interrupt while not open !\n"); + goto skip_a; + } + write_zsreg(uap_a, R0, RES_H_IUS); + zssync(uap_a); + if (r3 & CHAEXT) + pmz_status_handle(uap_a); + if (r3 & CHARxIP) + push = pmz_receive_chars(uap_a); + if (r3 & CHATxIP) + pmz_transmit_chars(uap_a); + rc = IRQ_HANDLED; + } + skip_a: + spin_unlock(&uap_a->port.lock); + if (push) + tty_flip_buffer_push(&uap->port.state->port); + + if (!uap_b) + goto out; + + spin_lock(&uap_b->port.lock); + push = false; + if (r3 & (CHBEXT | CHBTxIP | CHBRxIP)) { + if (!ZS_IS_OPEN(uap_b)) { + pmz_debug("ChanB interrupt while not open !\n"); + goto skip_b; + } + write_zsreg(uap_b, R0, RES_H_IUS); + zssync(uap_b); + if (r3 & CHBEXT) + pmz_status_handle(uap_b); + if (r3 & CHBRxIP) + push = pmz_receive_chars(uap_b); + if (r3 & CHBTxIP) + pmz_transmit_chars(uap_b); + rc = IRQ_HANDLED; + } + skip_b: + spin_unlock(&uap_b->port.lock); + if (push) + tty_flip_buffer_push(&uap->port.state->port); + + out: + return rc; +} + +/* + * Peek the status register, lock not held by caller + */ +static inline u8 pmz_peek_status(struct uart_pmac_port *uap) +{ + unsigned long flags; + u8 status; + + spin_lock_irqsave(&uap->port.lock, flags); + status = read_zsreg(uap, R0); + spin_unlock_irqrestore(&uap->port.lock, flags); + + return status; +} + +/* + * Check if transmitter is empty + * The port lock is not held. + */ +static unsigned int pmz_tx_empty(struct uart_port *port) +{ + unsigned char status; + + status = pmz_peek_status(to_pmz(port)); + if (status & Tx_BUF_EMP) + return TIOCSER_TEMT; + return 0; +} + +/* + * Set Modem Control (RTS & DTR) bits + * The port lock is held and interrupts are disabled. + * Note: Shall we really filter out RTS on external ports or + * should that be dealt at higher level only ? + */ +static void pmz_set_mctrl(struct uart_port *port, unsigned int mctrl) +{ + struct uart_pmac_port *uap = to_pmz(port); + unsigned char set_bits, clear_bits; + + /* Do nothing for irda for now... */ + if (ZS_IS_IRDA(uap)) + return; + /* We get called during boot with a port not up yet */ + if (!(ZS_IS_OPEN(uap) || ZS_IS_CONS(uap))) + return; + + set_bits = clear_bits = 0; + + if (ZS_IS_INTMODEM(uap)) { + if (mctrl & TIOCM_RTS) + set_bits |= RTS; + else + clear_bits |= RTS; + } + if (mctrl & TIOCM_DTR) + set_bits |= DTR; + else + clear_bits |= DTR; + + /* NOTE: Not subject to 'transmitter active' rule. */ + uap->curregs[R5] |= set_bits; + uap->curregs[R5] &= ~clear_bits; + + write_zsreg(uap, R5, uap->curregs[R5]); + pmz_debug("pmz_set_mctrl: set bits: %x, clear bits: %x -> %x\n", + set_bits, clear_bits, uap->curregs[R5]); + zssync(uap); +} + +/* + * Get Modem Control bits (only the input ones, the core will + * or that with a cached value of the control ones) + * The port lock is held and interrupts are disabled. + */ +static unsigned int pmz_get_mctrl(struct uart_port *port) +{ + struct uart_pmac_port *uap = to_pmz(port); + unsigned char status; + unsigned int ret; + + status = read_zsreg(uap, R0); + + ret = 0; + if (status & DCD) + ret |= TIOCM_CAR; + if (status & SYNC_HUNT) + ret |= TIOCM_DSR; + if (!(status & CTS)) + ret |= TIOCM_CTS; + + return ret; +} + +/* + * Stop TX side. Dealt like sunzilog at next Tx interrupt, + * though for DMA, we will have to do a bit more. + * The port lock is held and interrupts are disabled. + */ +static void pmz_stop_tx(struct uart_port *port) +{ + to_pmz(port)->flags |= PMACZILOG_FLAG_TX_STOPPED; +} + +/* + * Kick the Tx side. + * The port lock is held and interrupts are disabled. + */ +static void pmz_start_tx(struct uart_port *port) +{ + struct uart_pmac_port *uap = to_pmz(port); + unsigned char status; + + pmz_debug("pmz: start_tx()\n"); + + uap->flags |= PMACZILOG_FLAG_TX_ACTIVE; + uap->flags &= ~PMACZILOG_FLAG_TX_STOPPED; + + status = read_zsreg(uap, R0); + + /* TX busy? Just wait for the TX done interrupt. */ + if (!(status & Tx_BUF_EMP)) + return; + + /* Send the first character to jump-start the TX done + * IRQ sending engine. + */ + if (port->x_char) { + write_zsdata(uap, port->x_char); + zssync(uap); + port->icount.tx++; + port->x_char = 0; + } else { + struct circ_buf *xmit = &port->state->xmit; + + if (uart_circ_empty(xmit)) + goto out; + write_zsdata(uap, xmit->buf[xmit->tail]); + zssync(uap); + xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1); + port->icount.tx++; + + if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS) + uart_write_wakeup(&uap->port); + } + out: + pmz_debug("pmz: start_tx() done.\n"); +} + +/* + * Stop Rx side, basically disable emitting of + * Rx interrupts on the port. We don't disable the rx + * side of the chip proper though + * The port lock is held. + */ +static void pmz_stop_rx(struct uart_port *port) +{ + struct uart_pmac_port *uap = to_pmz(port); + + pmz_debug("pmz: stop_rx()()\n"); + + /* Disable all RX interrupts. */ + uap->curregs[R1] &= ~RxINT_MASK; + pmz_maybe_update_regs(uap); + + pmz_debug("pmz: stop_rx() done.\n"); +} + +/* + * Enable modem status change interrupts + * The port lock is held. + */ +static void pmz_enable_ms(struct uart_port *port) +{ + struct uart_pmac_port *uap = to_pmz(port); + unsigned char new_reg; + + if (ZS_IS_IRDA(uap)) + return; + new_reg = uap->curregs[R15] | (DCDIE | SYNCIE | CTSIE); + if (new_reg != uap->curregs[R15]) { + uap->curregs[R15] = new_reg; + + /* NOTE: Not subject to 'transmitter active' rule. */ + write_zsreg(uap, R15, uap->curregs[R15]); + } +} + +/* + * Control break state emission + * The port lock is not held. + */ +static void pmz_break_ctl(struct uart_port *port, int break_state) +{ + struct uart_pmac_port *uap = to_pmz(port); + unsigned char set_bits, clear_bits, new_reg; + unsigned long flags; + + set_bits = clear_bits = 0; + + if (break_state) + set_bits |= SND_BRK; + else + clear_bits |= SND_BRK; + + spin_lock_irqsave(&port->lock, flags); + + new_reg = (uap->curregs[R5] | set_bits) & ~clear_bits; + if (new_reg != uap->curregs[R5]) { + uap->curregs[R5] = new_reg; + write_zsreg(uap, R5, uap->curregs[R5]); + } + + spin_unlock_irqrestore(&port->lock, flags); +} + +#ifdef CONFIG_PPC_PMAC + +/* + * Turn power on or off to the SCC and associated stuff + * (port drivers, modem, IR port, etc.) + * Returns the number of milliseconds we should wait before + * trying to use the port. + */ +static int pmz_set_scc_power(struct uart_pmac_port *uap, int state) +{ + int delay = 0; + int rc; + + if (state) { + rc = pmac_call_feature( + PMAC_FTR_SCC_ENABLE, uap->node, uap->port_type, 1); + pmz_debug("port power on result: %d\n", rc); + if (ZS_IS_INTMODEM(uap)) { + rc = pmac_call_feature( + PMAC_FTR_MODEM_ENABLE, uap->node, 0, 1); + delay = 2500; /* wait for 2.5s before using */ + pmz_debug("modem power result: %d\n", rc); + } + } else { + /* TODO: Make that depend on a timer, don't power down + * immediately + */ + if (ZS_IS_INTMODEM(uap)) { + rc = pmac_call_feature( + PMAC_FTR_MODEM_ENABLE, uap->node, 0, 0); + pmz_debug("port power off result: %d\n", rc); + } + pmac_call_feature(PMAC_FTR_SCC_ENABLE, uap->node, uap->port_type, 0); + } + return delay; +} + +#else + +static int pmz_set_scc_power(struct uart_pmac_port *uap, int state) +{ + return 0; +} + +#endif /* !CONFIG_PPC_PMAC */ + +/* + * FixZeroBug....Works around a bug in the SCC receiving channel. + * Inspired from Darwin code, 15 Sept. 2000 -DanM + * + * The following sequence prevents a problem that is seen with O'Hare ASICs + * (most versions -- also with some Heathrow and Hydra ASICs) where a zero + * at the input to the receiver becomes 'stuck' and locks up the receiver. + * This problem can occur as a result of a zero bit at the receiver input + * coincident with any of the following events: + * + * The SCC is initialized (hardware or software). + * A framing error is detected. + * The clocking option changes from synchronous or X1 asynchronous + * clocking to X16, X32, or X64 asynchronous clocking. + * The decoding mode is changed among NRZ, NRZI, FM0, or FM1. + * + * This workaround attempts to recover from the lockup condition by placing + * the SCC in synchronous loopback mode with a fast clock before programming + * any of the asynchronous modes. + */ +static void pmz_fix_zero_bug_scc(struct uart_pmac_port *uap) +{ + write_zsreg(uap, 9, ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB); + zssync(uap); + udelay(10); + write_zsreg(uap, 9, (ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB) | NV); + zssync(uap); + + write_zsreg(uap, 4, X1CLK | MONSYNC); + write_zsreg(uap, 3, Rx8); + write_zsreg(uap, 5, Tx8 | RTS); + write_zsreg(uap, 9, NV); /* Didn't we already do this? */ + write_zsreg(uap, 11, RCBR | TCBR); + write_zsreg(uap, 12, 0); + write_zsreg(uap, 13, 0); + write_zsreg(uap, 14, (LOOPBAK | BRSRC)); + write_zsreg(uap, 14, (LOOPBAK | BRSRC | BRENAB)); + write_zsreg(uap, 3, Rx8 | RxENABLE); + write_zsreg(uap, 0, RES_EXT_INT); + write_zsreg(uap, 0, RES_EXT_INT); + write_zsreg(uap, 0, RES_EXT_INT); /* to kill some time */ + + /* The channel should be OK now, but it is probably receiving + * loopback garbage. + * Switch to asynchronous mode, disable the receiver, + * and discard everything in the receive buffer. + */ + write_zsreg(uap, 9, NV); + write_zsreg(uap, 4, X16CLK | SB_MASK); + write_zsreg(uap, 3, Rx8); + + while (read_zsreg(uap, 0) & Rx_CH_AV) { + (void)read_zsreg(uap, 8); + write_zsreg(uap, 0, RES_EXT_INT); + write_zsreg(uap, 0, ERR_RES); + } +} + +/* + * Real startup routine, powers up the hardware and sets up + * the SCC. Returns a delay in ms where you need to wait before + * actually using the port, this is typically the internal modem + * powerup delay. This routine expect the lock to be taken. + */ +static int __pmz_startup(struct uart_pmac_port *uap) +{ + int pwr_delay = 0; + + memset(&uap->curregs, 0, sizeof(uap->curregs)); + + /* Power up the SCC & underlying hardware (modem/irda) */ + pwr_delay = pmz_set_scc_power(uap, 1); + + /* Nice buggy HW ... */ + pmz_fix_zero_bug_scc(uap); + + /* Reset the channel */ + uap->curregs[R9] = 0; + write_zsreg(uap, 9, ZS_IS_CHANNEL_A(uap) ? CHRA : CHRB); + zssync(uap); + udelay(10); + write_zsreg(uap, 9, 0); + zssync(uap); + + /* Clear the interrupt registers */ + write_zsreg(uap, R1, 0); + write_zsreg(uap, R0, ERR_RES); + write_zsreg(uap, R0, ERR_RES); + write_zsreg(uap, R0, RES_H_IUS); + write_zsreg(uap, R0, RES_H_IUS); + + /* Setup some valid baud rate */ + uap->curregs[R4] = X16CLK | SB1; + uap->curregs[R3] = Rx8; + uap->curregs[R5] = Tx8 | RTS; + if (!ZS_IS_IRDA(uap)) + uap->curregs[R5] |= DTR; + uap->curregs[R12] = 0; + uap->curregs[R13] = 0; + uap->curregs[R14] = BRENAB; + + /* Clear handshaking, enable BREAK interrupts */ + uap->curregs[R15] = BRKIE; + + /* Master interrupt enable */ + uap->curregs[R9] |= NV | MIE; + + pmz_load_zsregs(uap, uap->curregs); + + /* Enable receiver and transmitter. */ + write_zsreg(uap, R3, uap->curregs[R3] |= RxENABLE); + write_zsreg(uap, R5, uap->curregs[R5] |= TxENABLE); + + /* Remember status for DCD/CTS changes */ + uap->prev_status = read_zsreg(uap, R0); + + return pwr_delay; +} + +static void pmz_irda_reset(struct uart_pmac_port *uap) +{ + unsigned long flags; + + spin_lock_irqsave(&uap->port.lock, flags); + uap->curregs[R5] |= DTR; + write_zsreg(uap, R5, uap->curregs[R5]); + zssync(uap); + spin_unlock_irqrestore(&uap->port.lock, flags); + msleep(110); + + spin_lock_irqsave(&uap->port.lock, flags); + uap->curregs[R5] &= ~DTR; + write_zsreg(uap, R5, uap->curregs[R5]); + zssync(uap); + spin_unlock_irqrestore(&uap->port.lock, flags); + msleep(10); +} + +/* + * This is the "normal" startup routine, using the above one + * wrapped with the lock and doing a schedule delay + */ +static int pmz_startup(struct uart_port *port) +{ + struct uart_pmac_port *uap = to_pmz(port); + unsigned long flags; + int pwr_delay = 0; + + pmz_debug("pmz: startup()\n"); + + uap->flags |= PMACZILOG_FLAG_IS_OPEN; + + /* A console is never powered down. Else, power up and + * initialize the chip + */ + if (!ZS_IS_CONS(uap)) { + spin_lock_irqsave(&port->lock, flags); + pwr_delay = __pmz_startup(uap); + spin_unlock_irqrestore(&port->lock, flags); + } + sprintf(uap->irq_name, PMACZILOG_NAME"%d", uap->port.line); + if (request_irq(uap->port.irq, pmz_interrupt, IRQF_SHARED, + uap->irq_name, uap)) { + pmz_error("Unable to register zs interrupt handler.\n"); + pmz_set_scc_power(uap, 0); + return -ENXIO; + } + + /* Right now, we deal with delay by blocking here, I'll be + * smarter later on + */ + if (pwr_delay != 0) { + pmz_debug("pmz: delaying %d ms\n", pwr_delay); + msleep(pwr_delay); + } + + /* IrDA reset is done now */ + if (ZS_IS_IRDA(uap)) + pmz_irda_reset(uap); + + /* Enable interrupt requests for the channel */ + spin_lock_irqsave(&port->lock, flags); + pmz_interrupt_control(uap, 1); + spin_unlock_irqrestore(&port->lock, flags); + + pmz_debug("pmz: startup() done.\n"); + + return 0; +} + +static void pmz_shutdown(struct uart_port *port) +{ + struct uart_pmac_port *uap = to_pmz(port); + unsigned long flags; + + pmz_debug("pmz: shutdown()\n"); + + spin_lock_irqsave(&port->lock, flags); + + /* Disable interrupt requests for the channel */ + pmz_interrupt_control(uap, 0); + + if (!ZS_IS_CONS(uap)) { + /* Disable receiver and transmitter */ + uap->curregs[R3] &= ~RxENABLE; + uap->curregs[R5] &= ~TxENABLE; + + /* Disable break assertion */ + uap->curregs[R5] &= ~SND_BRK; + pmz_maybe_update_regs(uap); + } + + spin_unlock_irqrestore(&port->lock, flags); + + /* Release interrupt handler */ + free_irq(uap->port.irq, uap); + + spin_lock_irqsave(&port->lock, flags); + + uap->flags &= ~PMACZILOG_FLAG_IS_OPEN; + + if (!ZS_IS_CONS(uap)) + pmz_set_scc_power(uap, 0); /* Shut the chip down */ + + spin_unlock_irqrestore(&port->lock, flags); + + pmz_debug("pmz: shutdown() done.\n"); +} + +/* Shared by TTY driver and serial console setup. The port lock is held + * and local interrupts are disabled. + */ +static void pmz_convert_to_zs(struct uart_pmac_port *uap, unsigned int cflag, + unsigned int iflag, unsigned long baud) +{ + int brg; + + /* Switch to external clocking for IrDA high clock rates. That + * code could be re-used for Midi interfaces with different + * multipliers + */ + if (baud >= 115200 && ZS_IS_IRDA(uap)) { + uap->curregs[R4] = X1CLK; + uap->curregs[R11] = RCTRxCP | TCTRxCP; + uap->curregs[R14] = 0; /* BRG off */ + uap->curregs[R12] = 0; + uap->curregs[R13] = 0; + uap->flags |= PMACZILOG_FLAG_IS_EXTCLK; + } else { + switch (baud) { + case ZS_CLOCK/16: /* 230400 */ + uap->curregs[R4] = X16CLK; + uap->curregs[R11] = 0; + uap->curregs[R14] = 0; + break; + case ZS_CLOCK/32: /* 115200 */ + uap->curregs[R4] = X32CLK; + uap->curregs[R11] = 0; + uap->curregs[R14] = 0; + break; + default: + uap->curregs[R4] = X16CLK; + uap->curregs[R11] = TCBR | RCBR; + brg = BPS_TO_BRG(baud, ZS_CLOCK / 16); + uap->curregs[R12] = (brg & 255); + uap->curregs[R13] = ((brg >> 8) & 255); + uap->curregs[R14] = BRENAB; + } + uap->flags &= ~PMACZILOG_FLAG_IS_EXTCLK; + } + + /* Character size, stop bits, and parity. */ + uap->curregs[3] &= ~RxN_MASK; + uap->curregs[5] &= ~TxN_MASK; + + switch (cflag & CSIZE) { + case CS5: + uap->curregs[3] |= Rx5; + uap->curregs[5] |= Tx5; + uap->parity_mask = 0x1f; + break; + case CS6: + uap->curregs[3] |= Rx6; + uap->curregs[5] |= Tx6; + uap->parity_mask = 0x3f; + break; + case CS7: + uap->curregs[3] |= Rx7; + uap->curregs[5] |= Tx7; + uap->parity_mask = 0x7f; + break; + case CS8: + default: + uap->curregs[3] |= Rx8; + uap->curregs[5] |= Tx8; + uap->parity_mask = 0xff; + break; + } + uap->curregs[4] &= ~(SB_MASK); + if (cflag & CSTOPB) + uap->curregs[4] |= SB2; + else + uap->curregs[4] |= SB1; + if (cflag & PARENB) + uap->curregs[4] |= PAR_ENAB; + else + uap->curregs[4] &= ~PAR_ENAB; + if (!(cflag & PARODD)) + uap->curregs[4] |= PAR_EVEN; + else + uap->curregs[4] &= ~PAR_EVEN; + + uap->port.read_status_mask = Rx_OVR; + if (iflag & INPCK) + uap->port.read_status_mask |= CRC_ERR | PAR_ERR; + if (iflag & (IGNBRK | BRKINT | PARMRK)) + uap->port.read_status_mask |= BRK_ABRT; + + uap->port.ignore_status_mask = 0; + if (iflag & IGNPAR) + uap->port.ignore_status_mask |= CRC_ERR | PAR_ERR; + if (iflag & IGNBRK) { + uap->port.ignore_status_mask |= BRK_ABRT; + if (iflag & IGNPAR) + uap->port.ignore_status_mask |= Rx_OVR; + } + + if ((cflag & CREAD) == 0) + uap->port.ignore_status_mask = 0xff; +} + + +/* + * Set the irda codec on the imac to the specified baud rate. + */ +static void pmz_irda_setup(struct uart_pmac_port *uap, unsigned long *baud) +{ + u8 cmdbyte; + int t, version; + + switch (*baud) { + /* SIR modes */ + case 2400: + cmdbyte = 0x53; + break; + case 4800: + cmdbyte = 0x52; + break; + case 9600: + cmdbyte = 0x51; + break; + case 19200: + cmdbyte = 0x50; + break; + case 38400: + cmdbyte = 0x4f; + break; + case 57600: + cmdbyte = 0x4e; + break; + case 115200: + cmdbyte = 0x4d; + break; + /* The FIR modes aren't really supported at this point, how + * do we select the speed ? via the FCR on KeyLargo ? + */ + case 1152000: + cmdbyte = 0; + break; + case 4000000: + cmdbyte = 0; + break; + default: /* 9600 */ + cmdbyte = 0x51; + *baud = 9600; + break; + } + + /* Wait for transmitter to drain */ + t = 10000; + while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0 + || (read_zsreg(uap, R1) & ALL_SNT) == 0) { + if (--t <= 0) { + pmz_error("transmitter didn't drain\n"); + return; + } + udelay(10); + } + + /* Drain the receiver too */ + t = 100; + (void)read_zsdata(uap); + (void)read_zsdata(uap); + (void)read_zsdata(uap); + mdelay(10); + while (read_zsreg(uap, R0) & Rx_CH_AV) { + read_zsdata(uap); + mdelay(10); + if (--t <= 0) { + pmz_error("receiver didn't drain\n"); + return; + } + } + + /* Switch to command mode */ + uap->curregs[R5] |= DTR; + write_zsreg(uap, R5, uap->curregs[R5]); + zssync(uap); + mdelay(1); + + /* Switch SCC to 19200 */ + pmz_convert_to_zs(uap, CS8, 0, 19200); + pmz_load_zsregs(uap, uap->curregs); + mdelay(1); + + /* Write get_version command byte */ + write_zsdata(uap, 1); + t = 5000; + while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) { + if (--t <= 0) { + pmz_error("irda_setup timed out on get_version byte\n"); + goto out; + } + udelay(10); + } + version = read_zsdata(uap); + + if (version < 4) { + pmz_info("IrDA: dongle version %d not supported\n", version); + goto out; + } + + /* Send speed mode */ + write_zsdata(uap, cmdbyte); + t = 5000; + while ((read_zsreg(uap, R0) & Rx_CH_AV) == 0) { + if (--t <= 0) { + pmz_error("irda_setup timed out on speed mode byte\n"); + goto out; + } + udelay(10); + } + t = read_zsdata(uap); + if (t != cmdbyte) + pmz_error("irda_setup speed mode byte = %x (%x)\n", t, cmdbyte); + + pmz_info("IrDA setup for %ld bps, dongle version: %d\n", + *baud, version); + + (void)read_zsdata(uap); + (void)read_zsdata(uap); + (void)read_zsdata(uap); + + out: + /* Switch back to data mode */ + uap->curregs[R5] &= ~DTR; + write_zsreg(uap, R5, uap->curregs[R5]); + zssync(uap); + + (void)read_zsdata(uap); + (void)read_zsdata(uap); + (void)read_zsdata(uap); +} + + +static void __pmz_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + struct uart_pmac_port *uap = to_pmz(port); + unsigned long baud; + + pmz_debug("pmz: set_termios()\n"); + + memcpy(&uap->termios_cache, termios, sizeof(struct ktermios)); + + /* XXX Check which revs of machines actually allow 1 and 4Mb speeds + * on the IR dongle. Note that the IRTTY driver currently doesn't know + * about the FIR mode and high speed modes. So these are unused. For + * implementing proper support for these, we should probably add some + * DMA as well, at least on the Rx side, which isn't a simple thing + * at this point. + */ + if (ZS_IS_IRDA(uap)) { + /* Calc baud rate */ + baud = uart_get_baud_rate(port, termios, old, 1200, 4000000); + pmz_debug("pmz: switch IRDA to %ld bauds\n", baud); + /* Cet the irda codec to the right rate */ + pmz_irda_setup(uap, &baud); + /* Set final baud rate */ + pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud); + pmz_load_zsregs(uap, uap->curregs); + zssync(uap); + } else { + baud = uart_get_baud_rate(port, termios, old, 1200, 230400); + pmz_convert_to_zs(uap, termios->c_cflag, termios->c_iflag, baud); + /* Make sure modem status interrupts are correctly configured */ + if (UART_ENABLE_MS(&uap->port, termios->c_cflag)) { + uap->curregs[R15] |= DCDIE | SYNCIE | CTSIE; + uap->flags |= PMACZILOG_FLAG_MODEM_STATUS; + } else { + uap->curregs[R15] &= ~(DCDIE | SYNCIE | CTSIE); + uap->flags &= ~PMACZILOG_FLAG_MODEM_STATUS; + } + + /* Load registers to the chip */ + pmz_maybe_update_regs(uap); + } + uart_update_timeout(port, termios->c_cflag, baud); + + pmz_debug("pmz: set_termios() done.\n"); +} + +/* The port lock is not held. */ +static void pmz_set_termios(struct uart_port *port, struct ktermios *termios, + struct ktermios *old) +{ + struct uart_pmac_port *uap = to_pmz(port); + unsigned long flags; + + spin_lock_irqsave(&port->lock, flags); + + /* Disable IRQs on the port */ + pmz_interrupt_control(uap, 0); + + /* Setup new port configuration */ + __pmz_set_termios(port, termios, old); + + /* Re-enable IRQs on the port */ + if (ZS_IS_OPEN(uap)) + pmz_interrupt_control(uap, 1); + + spin_unlock_irqrestore(&port->lock, flags); +} + +static const char *pmz_type(struct uart_port *port) +{ + struct uart_pmac_port *uap = to_pmz(port); + + if (ZS_IS_IRDA(uap)) + return "Z85c30 ESCC - Infrared port"; + else if (ZS_IS_INTMODEM(uap)) + return "Z85c30 ESCC - Internal modem"; + return "Z85c30 ESCC - Serial port"; +} + +/* We do not request/release mappings of the registers here, this + * happens at early serial probe time. + */ +static void pmz_release_port(struct uart_port *port) +{ +} + +static int pmz_request_port(struct uart_port *port) +{ + return 0; +} + +/* These do not need to do anything interesting either. */ +static void pmz_config_port(struct uart_port *port, int flags) +{ +} + +/* We do not support letting the user mess with the divisor, IRQ, etc. */ +static int pmz_verify_port(struct uart_port *port, struct serial_struct *ser) +{ + return -EINVAL; +} + +#ifdef CONFIG_CONSOLE_POLL + +static int pmz_poll_get_char(struct uart_port *port) +{ + struct uart_pmac_port *uap = + container_of(port, struct uart_pmac_port, port); + int tries = 2; + + while (tries) { + if ((read_zsreg(uap, R0) & Rx_CH_AV) != 0) + return read_zsdata(uap); + if (tries--) + udelay(5); + } + + return NO_POLL_CHAR; +} + +static void pmz_poll_put_char(struct uart_port *port, unsigned char c) +{ + struct uart_pmac_port *uap = + container_of(port, struct uart_pmac_port, port); + + /* Wait for the transmit buffer to empty. */ + while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0) + udelay(5); + write_zsdata(uap, c); +} + +#endif /* CONFIG_CONSOLE_POLL */ + +static const struct uart_ops pmz_pops = { + .tx_empty = pmz_tx_empty, + .set_mctrl = pmz_set_mctrl, + .get_mctrl = pmz_get_mctrl, + .stop_tx = pmz_stop_tx, + .start_tx = pmz_start_tx, + .stop_rx = pmz_stop_rx, + .enable_ms = pmz_enable_ms, + .break_ctl = pmz_break_ctl, + .startup = pmz_startup, + .shutdown = pmz_shutdown, + .set_termios = pmz_set_termios, + .type = pmz_type, + .release_port = pmz_release_port, + .request_port = pmz_request_port, + .config_port = pmz_config_port, + .verify_port = pmz_verify_port, +#ifdef CONFIG_CONSOLE_POLL + .poll_get_char = pmz_poll_get_char, + .poll_put_char = pmz_poll_put_char, +#endif +}; + +#ifdef CONFIG_PPC_PMAC + +/* + * Setup one port structure after probing, HW is down at this point, + * Unlike sunzilog, we don't need to pre-init the spinlock as we don't + * register our console before uart_add_one_port() is called + */ +static int __init pmz_init_port(struct uart_pmac_port *uap) +{ + struct device_node *np = uap->node; + const char *conn; + const struct slot_names_prop { + int count; + char name[1]; + } *slots; + int len; + struct resource r_ports, r_rxdma, r_txdma; + + /* + * Request & map chip registers + */ + if (of_address_to_resource(np, 0, &r_ports)) + return -ENODEV; + uap->port.mapbase = r_ports.start; + uap->port.membase = ioremap(uap->port.mapbase, 0x1000); + + uap->control_reg = uap->port.membase; + uap->data_reg = uap->control_reg + 0x10; + + /* + * Request & map DBDMA registers + */ +#ifdef HAS_DBDMA + if (of_address_to_resource(np, 1, &r_txdma) == 0 && + of_address_to_resource(np, 2, &r_rxdma) == 0) + uap->flags |= PMACZILOG_FLAG_HAS_DMA; +#else + memset(&r_txdma, 0, sizeof(struct resource)); + memset(&r_rxdma, 0, sizeof(struct resource)); +#endif + if (ZS_HAS_DMA(uap)) { + uap->tx_dma_regs = ioremap(r_txdma.start, 0x100); + if (uap->tx_dma_regs == NULL) { + uap->flags &= ~PMACZILOG_FLAG_HAS_DMA; + goto no_dma; + } + uap->rx_dma_regs = ioremap(r_rxdma.start, 0x100); + if (uap->rx_dma_regs == NULL) { + iounmap(uap->tx_dma_regs); + uap->tx_dma_regs = NULL; + uap->flags &= ~PMACZILOG_FLAG_HAS_DMA; + goto no_dma; + } + uap->tx_dma_irq = irq_of_parse_and_map(np, 1); + uap->rx_dma_irq = irq_of_parse_and_map(np, 2); + } +no_dma: + + /* + * Detect port type + */ + if (of_device_is_compatible(np, "cobalt")) + uap->flags |= PMACZILOG_FLAG_IS_INTMODEM; + conn = of_get_property(np, "AAPL,connector", &len); + if (conn && (strcmp(conn, "infrared") == 0)) + uap->flags |= PMACZILOG_FLAG_IS_IRDA; + uap->port_type = PMAC_SCC_ASYNC; + /* 1999 Powerbook G3 has slot-names property instead */ + slots = of_get_property(np, "slot-names", &len); + if (slots && slots->count > 0) { + if (strcmp(slots->name, "IrDA") == 0) + uap->flags |= PMACZILOG_FLAG_IS_IRDA; + else if (strcmp(slots->name, "Modem") == 0) + uap->flags |= PMACZILOG_FLAG_IS_INTMODEM; + } + if (ZS_IS_IRDA(uap)) + uap->port_type = PMAC_SCC_IRDA; + if (ZS_IS_INTMODEM(uap)) { + struct device_node* i2c_modem = + of_find_node_by_name(NULL, "i2c-modem"); + if (i2c_modem) { + const char* mid = + of_get_property(i2c_modem, "modem-id", NULL); + if (mid) switch(*mid) { + case 0x04 : + case 0x05 : + case 0x07 : + case 0x08 : + case 0x0b : + case 0x0c : + uap->port_type = PMAC_SCC_I2S1; + } + printk(KERN_INFO "pmac_zilog: i2c-modem detected, id: %d\n", + mid ? (*mid) : 0); + of_node_put(i2c_modem); + } else { + printk(KERN_INFO "pmac_zilog: serial modem detected\n"); + } + } + + /* + * Init remaining bits of "port" structure + */ + uap->port.iotype = UPIO_MEM; + uap->port.irq = irq_of_parse_and_map(np, 0); + uap->port.uartclk = ZS_CLOCK; + uap->port.fifosize = 1; + uap->port.ops = &pmz_pops; + uap->port.type = PORT_PMAC_ZILOG; + uap->port.flags = 0; + + /* + * Fixup for the port on Gatwick for which the device-tree has + * missing interrupts. Normally, the macio_dev would contain + * fixed up interrupt info, but we use the device-tree directly + * here due to early probing so we need the fixup too. + */ + if (uap->port.irq == 0 && + np->parent && np->parent->parent && + of_device_is_compatible(np->parent->parent, "gatwick")) { + /* IRQs on gatwick are offset by 64 */ + uap->port.irq = irq_create_mapping(NULL, 64 + 15); + uap->tx_dma_irq = irq_create_mapping(NULL, 64 + 4); + uap->rx_dma_irq = irq_create_mapping(NULL, 64 + 5); + } + + /* Setup some valid baud rate information in the register + * shadows so we don't write crap there before baud rate is + * first initialized. + */ + pmz_convert_to_zs(uap, CS8, 0, 9600); + + return 0; +} + +/* + * Get rid of a port on module removal + */ +static void pmz_dispose_port(struct uart_pmac_port *uap) +{ + struct device_node *np; + + np = uap->node; + iounmap(uap->rx_dma_regs); + iounmap(uap->tx_dma_regs); + iounmap(uap->control_reg); + uap->node = NULL; + of_node_put(np); + memset(uap, 0, sizeof(struct uart_pmac_port)); +} + +/* + * Called upon match with an escc node in the device-tree. + */ +static int pmz_attach(struct macio_dev *mdev, const struct of_device_id *match) +{ + struct uart_pmac_port *uap; + int i; + + /* Iterate the pmz_ports array to find a matching entry + */ + for (i = 0; i < MAX_ZS_PORTS; i++) + if (pmz_ports[i].node == mdev->ofdev.dev.of_node) + break; + if (i >= MAX_ZS_PORTS) + return -ENODEV; + + + uap = &pmz_ports[i]; + uap->dev = mdev; + uap->port.dev = &mdev->ofdev.dev; + dev_set_drvdata(&mdev->ofdev.dev, uap); + + /* We still activate the port even when failing to request resources + * to work around bugs in ancient Apple device-trees + */ + if (macio_request_resources(uap->dev, "pmac_zilog")) + printk(KERN_WARNING "%pOFn: Failed to request resource" + ", port still active\n", + uap->node); + else + uap->flags |= PMACZILOG_FLAG_RSRC_REQUESTED; + + return uart_add_one_port(&pmz_uart_reg, &uap->port); +} + +/* + * That one should not be called, macio isn't really a hotswap device, + * we don't expect one of those serial ports to go away... + */ +static int pmz_detach(struct macio_dev *mdev) +{ + struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev); + + if (!uap) + return -ENODEV; + + uart_remove_one_port(&pmz_uart_reg, &uap->port); + + if (uap->flags & PMACZILOG_FLAG_RSRC_REQUESTED) { + macio_release_resources(uap->dev); + uap->flags &= ~PMACZILOG_FLAG_RSRC_REQUESTED; + } + dev_set_drvdata(&mdev->ofdev.dev, NULL); + uap->dev = NULL; + uap->port.dev = NULL; + + return 0; +} + + +static int pmz_suspend(struct macio_dev *mdev, pm_message_t pm_state) +{ + struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev); + + if (uap == NULL) { + printk("HRM... pmz_suspend with NULL uap\n"); + return 0; + } + + uart_suspend_port(&pmz_uart_reg, &uap->port); + + return 0; +} + + +static int pmz_resume(struct macio_dev *mdev) +{ + struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev); + + if (uap == NULL) + return 0; + + uart_resume_port(&pmz_uart_reg, &uap->port); + + return 0; +} + +/* + * Probe all ports in the system and build the ports array, we register + * with the serial layer later, so we get a proper struct device which + * allows the tty to attach properly. This is later than it used to be + * but the tty layer really wants it that way. + */ +static int __init pmz_probe(void) +{ + struct device_node *node_p, *node_a, *node_b, *np; + int count = 0; + int rc; + + /* + * Find all escc chips in the system + */ + for_each_node_by_name(node_p, "escc") { + /* + * First get channel A/B node pointers + * + * TODO: Add routines with proper locking to do that... + */ + node_a = node_b = NULL; + for_each_child_of_node(node_p, np) { + if (of_node_name_prefix(np, "ch-a")) + node_a = of_node_get(np); + else if (of_node_name_prefix(np, "ch-b")) + node_b = of_node_get(np); + } + if (!node_a && !node_b) { + of_node_put(node_a); + of_node_put(node_b); + printk(KERN_ERR "pmac_zilog: missing node %c for escc %pOF\n", + (!node_a) ? 'a' : 'b', node_p); + continue; + } + + /* + * Fill basic fields in the port structures + */ + if (node_b != NULL) { + pmz_ports[count].mate = &pmz_ports[count+1]; + pmz_ports[count+1].mate = &pmz_ports[count]; + } + pmz_ports[count].flags = PMACZILOG_FLAG_IS_CHANNEL_A; + pmz_ports[count].node = node_a; + pmz_ports[count+1].node = node_b; + pmz_ports[count].port.line = count; + pmz_ports[count+1].port.line = count+1; + + /* + * Setup the ports for real + */ + rc = pmz_init_port(&pmz_ports[count]); + if (rc == 0 && node_b != NULL) + rc = pmz_init_port(&pmz_ports[count+1]); + if (rc != 0) { + of_node_put(node_a); + of_node_put(node_b); + memset(&pmz_ports[count], 0, sizeof(struct uart_pmac_port)); + memset(&pmz_ports[count+1], 0, sizeof(struct uart_pmac_port)); + continue; + } + count += 2; + } + pmz_ports_count = count; + + return 0; +} + +#else + +/* On PCI PowerMacs, pmz_probe() does an explicit search of the OpenFirmware + * tree to obtain the device_nodes needed to start the console before the + * macio driver. On Macs without OpenFirmware, global platform_devices take + * the place of those device_nodes. + */ +extern struct platform_device scc_a_pdev, scc_b_pdev; + +static int __init pmz_init_port(struct uart_pmac_port *uap) +{ + struct resource *r_ports, *r_irq; + + r_ports = platform_get_resource(uap->pdev, IORESOURCE_MEM, 0); + r_irq = platform_get_resource(uap->pdev, IORESOURCE_IRQ, 0); + if (!r_ports || !r_irq) + return -ENODEV; + + uap->port.mapbase = r_ports->start; + uap->port.membase = (unsigned char __iomem *) r_ports->start; + uap->port.iotype = UPIO_MEM; + uap->port.irq = r_irq->start; + uap->port.uartclk = ZS_CLOCK; + uap->port.fifosize = 1; + uap->port.ops = &pmz_pops; + uap->port.type = PORT_PMAC_ZILOG; + uap->port.flags = 0; + + uap->control_reg = uap->port.membase; + uap->data_reg = uap->control_reg + 4; + uap->port_type = 0; + uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_PMACZILOG_CONSOLE); + + pmz_convert_to_zs(uap, CS8, 0, 9600); + + return 0; +} + +static int __init pmz_probe(void) +{ + int err; + + pmz_ports_count = 0; + + pmz_ports[0].port.line = 0; + pmz_ports[0].flags = PMACZILOG_FLAG_IS_CHANNEL_A; + pmz_ports[0].pdev = &scc_a_pdev; + err = pmz_init_port(&pmz_ports[0]); + if (err) + return err; + pmz_ports_count++; + + pmz_ports[0].mate = &pmz_ports[1]; + pmz_ports[1].mate = &pmz_ports[0]; + pmz_ports[1].port.line = 1; + pmz_ports[1].flags = 0; + pmz_ports[1].pdev = &scc_b_pdev; + err = pmz_init_port(&pmz_ports[1]); + if (err) + return err; + pmz_ports_count++; + + return 0; +} + +static void pmz_dispose_port(struct uart_pmac_port *uap) +{ + memset(uap, 0, sizeof(struct uart_pmac_port)); +} + +static int __init pmz_attach(struct platform_device *pdev) +{ + struct uart_pmac_port *uap; + int i; + + /* Iterate the pmz_ports array to find a matching entry */ + for (i = 0; i < pmz_ports_count; i++) + if (pmz_ports[i].pdev == pdev) + break; + if (i >= pmz_ports_count) + return -ENODEV; + + uap = &pmz_ports[i]; + uap->port.dev = &pdev->dev; + platform_set_drvdata(pdev, uap); + + return uart_add_one_port(&pmz_uart_reg, &uap->port); +} + +static int __exit pmz_detach(struct platform_device *pdev) +{ + struct uart_pmac_port *uap = platform_get_drvdata(pdev); + + if (!uap) + return -ENODEV; + + uart_remove_one_port(&pmz_uart_reg, &uap->port); + + uap->port.dev = NULL; + + return 0; +} + +#endif /* !CONFIG_PPC_PMAC */ + +#ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE + +static void pmz_console_write(struct console *con, const char *s, unsigned int count); +static int __init pmz_console_setup(struct console *co, char *options); + +static struct console pmz_console = { + .name = PMACZILOG_NAME, + .write = pmz_console_write, + .device = uart_console_device, + .setup = pmz_console_setup, + .flags = CON_PRINTBUFFER, + .index = -1, + .data = &pmz_uart_reg, +}; + +#define PMACZILOG_CONSOLE &pmz_console +#else /* CONFIG_SERIAL_PMACZILOG_CONSOLE */ +#define PMACZILOG_CONSOLE (NULL) +#endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */ + +/* + * Register the driver, console driver and ports with the serial + * core + */ +static int __init pmz_register(void) +{ + pmz_uart_reg.nr = pmz_ports_count; + pmz_uart_reg.cons = PMACZILOG_CONSOLE; + + /* + * Register this driver with the serial core + */ + return uart_register_driver(&pmz_uart_reg); +} + +#ifdef CONFIG_PPC_PMAC + +static const struct of_device_id pmz_match[] = +{ + { + .name = "ch-a", + }, + { + .name = "ch-b", + }, + {}, +}; +MODULE_DEVICE_TABLE (of, pmz_match); + +static struct macio_driver pmz_driver = { + .driver = { + .name = "pmac_zilog", + .owner = THIS_MODULE, + .of_match_table = pmz_match, + }, + .probe = pmz_attach, + .remove = pmz_detach, + .suspend = pmz_suspend, + .resume = pmz_resume, +}; + +#else + +static struct platform_driver pmz_driver = { + .remove = __exit_p(pmz_detach), + .driver = { + .name = "scc", + }, +}; + +#endif /* !CONFIG_PPC_PMAC */ + +static int __init init_pmz(void) +{ + int rc, i; + printk(KERN_INFO "%s\n", version); + + /* + * First, we need to do a direct OF-based probe pass. We + * do that because we want serial console up before the + * macio stuffs calls us back, and since that makes it + * easier to pass the proper number of channels to + * uart_register_driver() + */ + if (pmz_ports_count == 0) + pmz_probe(); + + /* + * Bail early if no port found + */ + if (pmz_ports_count == 0) + return -ENODEV; + + /* + * Now we register with the serial layer + */ + rc = pmz_register(); + if (rc) { + printk(KERN_ERR + "pmac_zilog: Error registering serial device, disabling pmac_zilog.\n" + "pmac_zilog: Did another serial driver already claim the minors?\n"); + /* effectively "pmz_unprobe()" */ + for (i=0; i < pmz_ports_count; i++) + pmz_dispose_port(&pmz_ports[i]); + return rc; + } + + /* + * Then we register the macio driver itself + */ +#ifdef CONFIG_PPC_PMAC + return macio_register_driver(&pmz_driver); +#else + return platform_driver_probe(&pmz_driver, pmz_attach); +#endif +} + +static void __exit exit_pmz(void) +{ + int i; + +#ifdef CONFIG_PPC_PMAC + /* Get rid of macio-driver (detach from macio) */ + macio_unregister_driver(&pmz_driver); +#else + platform_driver_unregister(&pmz_driver); +#endif + + for (i = 0; i < pmz_ports_count; i++) { + struct uart_pmac_port *uport = &pmz_ports[i]; +#ifdef CONFIG_PPC_PMAC + if (uport->node != NULL) + pmz_dispose_port(uport); +#else + if (uport->pdev != NULL) + pmz_dispose_port(uport); +#endif + } + /* Unregister UART driver */ + uart_unregister_driver(&pmz_uart_reg); +} + +#ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE + +static void pmz_console_putchar(struct uart_port *port, int ch) +{ + struct uart_pmac_port *uap = + container_of(port, struct uart_pmac_port, port); + + /* Wait for the transmit buffer to empty. */ + while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0) + udelay(5); + write_zsdata(uap, ch); +} + +/* + * Print a string to the serial port trying not to disturb + * any possible real use of the port... + */ +static void pmz_console_write(struct console *con, const char *s, unsigned int count) +{ + struct uart_pmac_port *uap = &pmz_ports[con->index]; + unsigned long flags; + + spin_lock_irqsave(&uap->port.lock, flags); + + /* Turn of interrupts and enable the transmitter. */ + write_zsreg(uap, R1, uap->curregs[1] & ~TxINT_ENAB); + write_zsreg(uap, R5, uap->curregs[5] | TxENABLE | RTS | DTR); + + uart_console_write(&uap->port, s, count, pmz_console_putchar); + + /* Restore the values in the registers. */ + write_zsreg(uap, R1, uap->curregs[1]); + /* Don't disable the transmitter. */ + + spin_unlock_irqrestore(&uap->port.lock, flags); +} + +/* + * Setup the serial console + */ +static int __init pmz_console_setup(struct console *co, char *options) +{ + struct uart_pmac_port *uap; + struct uart_port *port; + int baud = 38400; + int bits = 8; + int parity = 'n'; + int flow = 'n'; + unsigned long pwr_delay; + + /* + * XServe's default to 57600 bps + */ + if (of_machine_is_compatible("RackMac1,1") + || of_machine_is_compatible("RackMac1,2") + || of_machine_is_compatible("MacRISC4")) + baud = 57600; + + /* + * Check whether an invalid uart number has been specified, and + * if so, search for the first available port that does have + * console support. + */ + if (co->index >= pmz_ports_count) + co->index = 0; + uap = &pmz_ports[co->index]; +#ifdef CONFIG_PPC_PMAC + if (uap->node == NULL) + return -ENODEV; +#else + if (uap->pdev == NULL) + return -ENODEV; +#endif + port = &uap->port; + + /* + * Mark port as beeing a console + */ + uap->flags |= PMACZILOG_FLAG_IS_CONS; + + /* + * Temporary fix for uart layer who didn't setup the spinlock yet + */ + spin_lock_init(&port->lock); + + /* + * Enable the hardware + */ + pwr_delay = __pmz_startup(uap); + if (pwr_delay) + mdelay(pwr_delay); + + if (options) + uart_parse_options(options, &baud, &parity, &bits, &flow); + + return uart_set_options(port, co, baud, parity, bits, flow); +} + +static int __init pmz_console_init(void) +{ + /* Probe ports */ + pmz_probe(); + + if (pmz_ports_count == 0) + return -ENODEV; + + /* TODO: Autoprobe console based on OF */ + /* pmz_console.index = i; */ + register_console(&pmz_console); + + return 0; + +} +console_initcall(pmz_console_init); +#endif /* CONFIG_SERIAL_PMACZILOG_CONSOLE */ + +module_init(init_pmz); +module_exit(exit_pmz); |