pmac_zilog.c

Linux Kernel 2.6.9 for OMAP1710

/*
 * Called upon match with an escc node in the devive-tree.
 */
static int pmz_attach(struct macio_dev *mdev, const struct of_match *match)
{
	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.node) {
			struct uart_pmac_port *uap = &pmz_ports[i];

			uap->dev = mdev;
			dev_set_drvdata(&mdev->ofdev.dev, uap);
			if (macio_request_resources(uap->dev, "pmac_zilog"))
				printk(KERN_WARNING "%s: Failed to request resource"
				       ", port still active\n",
				       uap->node->name);
			else
				uap->flags |= PMACZILOG_FLAG_RSRC_REQUESTED;				
			return 0;
		}
	return -ENODEV;
}

/*
 * 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;

	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;
	
	return 0;
}


static int pmz_suspend(struct macio_dev *mdev, u32 pm_state)
{
	struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
	struct uart_state *state;
	unsigned long flags;

	if (uap == NULL) {
		printk("HRM... pmz_suspend with NULL uap\n");
		return 0;
	}

	if (pm_state == mdev->ofdev.dev.power_state || pm_state < 2)
		return 0;

	pmz_debug("suspend, switching to state %d\n", pm_state);

	state = pmz_uart_reg.state + uap->port.line;

	down(&pmz_irq_sem);
	down(&state->sem);

	spin_lock_irqsave(&uap->port.lock, flags);

	if (ZS_IS_OPEN(uap) || ZS_IS_CONS(uap)) {
		/* Disable receiver and transmitter.  */
		uap->curregs[R3] &= ~RxENABLE;
		uap->curregs[R5] &= ~TxENABLE;

		/* Disable all interrupts and BRK assertion.  */
		uap->curregs[R1] &= ~(EXT_INT_ENAB | TxINT_ENAB | RxINT_MASK);
		uap->curregs[R5] &= ~SND_BRK;
		pmz_load_zsregs(uap, uap->curregs);
		uap->flags |= PMACZILOG_FLAG_IS_ASLEEP;
		mb();
	}

	spin_unlock_irqrestore(&uap->port.lock, flags);

	if (ZS_IS_OPEN(uap) || ZS_IS_OPEN(uap->mate))
		if (ZS_IS_ASLEEP(uap->mate) && ZS_IS_IRQ_ON(pmz_get_port_A(uap))) {
			pmz_get_port_A(uap)->flags &= ~PMACZILOG_FLAG_IS_IRQ_ON;
			disable_irq(uap->port.irq);
		}

	if (ZS_IS_CONS(uap))
		uap->port.cons->flags &= ~CON_ENABLED;

	/* Shut the chip down */
	pmz_set_scc_power(uap, 0);

	up(&state->sem);
	up(&pmz_irq_sem);

	pmz_debug("suspend, switching complete\n");

	mdev->ofdev.dev.power_state = pm_state;

	return 0;
}


static int pmz_resume(struct macio_dev *mdev)
{
	struct uart_pmac_port *uap = dev_get_drvdata(&mdev->ofdev.dev);
	struct uart_state *state;
	unsigned long flags;
	int pwr_delay = 0;

	if (uap == NULL)
		return 0;

	if (mdev->ofdev.dev.power_state == 0)
		return 0;
	
	pmz_debug("resume, switching to state 0\n");

	state = pmz_uart_reg.state + uap->port.line;

	down(&pmz_irq_sem);
	down(&state->sem);

	spin_lock_irqsave(&uap->port.lock, flags);
	if (!ZS_IS_OPEN(uap) && !ZS_IS_CONS(uap)) {
		spin_unlock_irqrestore(&uap->port.lock, flags);
		goto bail;
	}
	pwr_delay = __pmz_startup(uap);

	/* Take care of config that may have changed while asleep */
	__pmz_set_termios(&uap->port, &uap->termios_cache, NULL);

	if (ZS_IS_OPEN(uap)) {
		/* Enable interrupts */		
		uap->curregs[R1] |= INT_ALL_Rx | TxINT_ENAB;
		if (!ZS_IS_EXTCLK(uap))
			uap->curregs[R1] |= EXT_INT_ENAB;
		write_zsreg(uap, R1, uap->curregs[R1]);
	}

	spin_unlock_irqrestore(&uap->port.lock, flags);

	if (ZS_IS_CONS(uap))
		uap->port.cons->flags |= CON_ENABLED;

	/* Re-enable IRQ on the controller */
	if (ZS_IS_OPEN(uap) && !ZS_IS_IRQ_ON(pmz_get_port_A(uap))) {
		pmz_get_port_A(uap)->flags |= PMACZILOG_FLAG_IS_IRQ_ON;
		enable_irq(uap->port.irq);
	}

 bail:
	up(&state->sem);
	up(&pmz_irq_sem);

	/* 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);
		set_current_state(TASK_UNINTERRUPTIBLE);
		schedule_timeout((pwr_delay * HZ)/1000);
	}

	pmz_debug("resume, switching complete\n");

	mdev->ofdev.dev.power_state = 0;

	return 0;
}

/*
 * Probe all ports in the system and build the ports array, we register
 * with the serial layer at this point, the macio-type probing is only
 * used later to "attach" to the sysfs tree so we get power management
 * events
 */
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
	 */
	node_p = of_find_node_by_name(NULL, "escc");
	while (node_p) {
		/*
		 * First get channel A/B node pointers
		 * 
		 * TODO: Add routines with proper locking to do that...
		 */
		node_a = node_b = NULL;
		for (np = NULL; (np = of_get_next_child(node_p, np)) != NULL;) {
			if (strncmp(np->name, "ch-a", 4) == 0)
				node_a = of_node_get(np);
			else if (strncmp(np->name, "ch-b", 4) == 0)
				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 %s\n",
				(!node_a) ? 'a' : 'b', node_p->full_name);
			goto next;
		}

		/*
		 * Fill basic fields in the port structures
		 */
		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));
			goto next;
		}
		count += 2;
next:
		node_p = of_find_node_by_name(node_p, "escc");
	}
	pmz_ports_count = count;

	return 0;
}

#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	=	"ttyS",
	.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)
{
	int i, rc;
	
	pmz_uart_reg.nr = pmz_ports_count;
	pmz_uart_reg.cons = PMACZILOG_CONSOLE;
	pmz_uart_reg.minor = 64;

	/*
	 * Register this driver with the serial core
	 */
	rc = uart_register_driver(&pmz_uart_reg);
	if (rc)
		return rc;

	/*
	 * Register each port with the serial core
	 */
	for (i = 0; i < pmz_ports_count; i++) {
		struct uart_pmac_port *uport = &pmz_ports[i];
		/* NULL node may happen on wallstreet */
		if (uport->node != NULL)
			rc = uart_add_one_port(&pmz_uart_reg, &uport->port);
		if (rc)
			goto err_out;
	}

	return 0;
err_out:
	while (i-- > 0) {
		struct uart_pmac_port *uport = &pmz_ports[i];
		uart_remove_one_port(&pmz_uart_reg, &uport->port);
	}
	uart_unregister_driver(&pmz_uart_reg);
	return rc;
}

static struct of_match pmz_match[] = 
{
	{
	.name 		= "ch-a",
	.type		= OF_ANY_MATCH,
	.compatible	= OF_ANY_MATCH
	},
	{
	.name 		= "ch-b",
	.type		= OF_ANY_MATCH,
	.compatible	= OF_ANY_MATCH
	},
	{},
};

static struct macio_driver pmz_driver = 
{
	.name 		= "pmac_zilog",
	.match_table	= pmz_match,
	.probe		= pmz_attach,
	.remove		= pmz_detach,
	.suspend	= pmz_suspend,
       	.resume		= pmz_resume,
};

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
	 */
	return macio_register_driver(&pmz_driver);
}

static void __exit exit_pmz(void)
{
	int i;

	/* Get rid of macio-driver (detach from macio) */
	macio_unregister_driver(&pmz_driver);

	for (i = 0; i < pmz_ports_count; i++) {
		struct uart_pmac_port *uport = &pmz_ports[i];
		if (uport->node != NULL) {
			uart_remove_one_port(&pmz_uart_reg, &uport->port);
			pmz_dispose_port(uport);
		}
	}
	/* Unregister UART driver */
	uart_unregister_driver(&pmz_uart_reg);
}

#ifdef CONFIG_SERIAL_PMACZILOG_CONSOLE

/*
 * 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;
	int i;

	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);

	for (i = 0; i < count; i++) {
		/* Wait for the transmit buffer to empty. */
		while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0)
			udelay(5);
		write_zsdata(uap, s[i]);
		if (s[i] == 10) {
			while ((read_zsreg(uap, R0) & Tx_BUF_EMP) == 0)
				udelay(5);
			write_zsdata(uap, R13);
		}
	}

	/* 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 (machine_is_compatible("RackMac1,1")
	    || machine_is_compatible("RackMac1,2")
	    || 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];
	if (uap->node == NULL)
		return -ENODEV;
	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();

	/* 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);