[mirror_ubuntu-artful-kernel.git] / drivers / tty / serial / sunhv.c

/* sunhv.c: Serial driver for SUN4V hypervisor console.
 *
 * Copyright (C) 2006, 2007 David S. Miller (davem@davemloft.net)
 */

#include <linux/kernel.h>
#include <linux/errno.h>
#include <linux/tty.h>
#include <linux/tty_flip.h>
#include <linux/major.h>
#include <linux/circ_buf.h>
#include <linux/serial.h>
#include <linux/sysrq.h>
#include <linux/console.h>
#include <linux/spinlock.h>
#include <linux/slab.h>
#include <linux/delay.h>
#include <linux/init.h>
#include <linux/of_device.h>

#include <asm/hypervisor.h>
#include <asm/spitfire.h>
#include <asm/prom.h>
#include <asm/irq.h>
#include <asm/setup.h>

#if defined(CONFIG_MAGIC_SYSRQ)
#define SUPPORT_SYSRQ
#endif

#include <linux/serial_core.h>
#include <linux/sunserialcore.h>

#define CON_BREAK	((long)-1)
#define CON_HUP		((long)-2)

#define IGNORE_BREAK	0x1
#define IGNORE_ALL	0x2

static char *con_write_page;
static char *con_read_page;

static int hung_up = 0;

static void transmit_chars_putchar(struct uart_port *port, struct circ_buf *xmit)
{
	while (!uart_circ_empty(xmit)) {
		long status = sun4v_con_putchar(xmit->buf[xmit->tail]);

		if (status != HV_EOK)
			break;

		xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
		port->icount.tx++;
	}
}

static void transmit_chars_write(struct uart_port *port, struct circ_buf *xmit)
{
	while (!uart_circ_empty(xmit)) {
		unsigned long ra = __pa(xmit->buf + xmit->tail);
		unsigned long len, status, sent;

		len = CIRC_CNT_TO_END(xmit->head, xmit->tail,
				      UART_XMIT_SIZE);
		status = sun4v_con_write(ra, len, &sent);
		if (status != HV_EOK)
			break;
		xmit->tail = (xmit->tail + sent) & (UART_XMIT_SIZE - 1);
		port->icount.tx += sent;
	}
}

static int receive_chars_getchar(struct uart_port *port)
{
	int saw_console_brk = 0;
	int limit = 10000;

	while (limit-- > 0) {
		long status;
		long c = sun4v_con_getchar(&status);

		if (status == HV_EWOULDBLOCK)
			break;

		if (c == CON_BREAK) {
			if (uart_handle_break(port))
				continue;
			saw_console_brk = 1;
			c = 0;
		}

		if (c == CON_HUP) {
			hung_up = 1;
			uart_handle_dcd_change(port, 0);
		} else if (hung_up) {
			hung_up = 0;
			uart_handle_dcd_change(port, 1);
		}

		if (port->state == NULL) {
			uart_handle_sysrq_char(port, c);
			continue;
		}

		port->icount.rx++;

		if (uart_handle_sysrq_char(port, c))
			continue;

		tty_insert_flip_char(&port->state->port, c, TTY_NORMAL);
	}

	return saw_console_brk;
}

static int receive_chars_read(struct uart_port *port)
{
	int saw_console_brk = 0;
	int limit = 10000;

	while (limit-- > 0) {
		unsigned long ra = __pa(con_read_page);
		unsigned long bytes_read, i;
		long stat = sun4v_con_read(ra, PAGE_SIZE, &bytes_read);

		if (stat != HV_EOK) {
			bytes_read = 0;

			if (stat == CON_BREAK) {
				if (uart_handle_break(port))
					continue;
				saw_console_brk = 1;
				*con_read_page = 0;
				bytes_read = 1;
			} else if (stat == CON_HUP) {
				hung_up = 1;
				uart_handle_dcd_change(port, 0);
				continue;
			} else {
				/* HV_EWOULDBLOCK, etc.  */
				break;
			}
		}

		if (hung_up) {
			hung_up = 0;
			uart_handle_dcd_change(port, 1);
		}

		if (port->sysrq != 0 &&  *con_read_page) {
			for (i = 0; i < bytes_read; i++)
				uart_handle_sysrq_char(port, con_read_page[i]);
		}

		if (port->state == NULL)
			continue;

		port->icount.rx += bytes_read;

		tty_insert_flip_string(&port->state->port, con_read_page,
				bytes_read);
	}

	return saw_console_brk;
}

struct sunhv_ops {
	void (*transmit_chars)(struct uart_port *port, struct circ_buf *xmit);
	int (*receive_chars)(struct uart_port *port);
};

static const struct sunhv_ops bychar_ops = {
	.transmit_chars = transmit_chars_putchar,
	.receive_chars = receive_chars_getchar,
};

static const struct sunhv_ops bywrite_ops = {
	.transmit_chars = transmit_chars_write,
	.receive_chars = receive_chars_read,
};

static const struct sunhv_ops *sunhv_ops = &bychar_ops;

static struct tty_port *receive_chars(struct uart_port *port)
{
	struct tty_port *tport = NULL;

	if (port->state != NULL)		/* Unopened serial console */
		tport = &port->state->port;

	if (sunhv_ops->receive_chars(port))
		sun_do_break();

	return tport;
}

static void transmit_chars(struct uart_port *port)
{
	struct circ_buf *xmit;

	if (!port->state)
		return;

	xmit = &port->state->xmit;
	if (uart_circ_empty(xmit) || uart_tx_stopped(port))
		return;

	sunhv_ops->transmit_chars(port, xmit);

	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
		uart_write_wakeup(port);
}

static irqreturn_t sunhv_interrupt(int irq, void *dev_id)
{
	struct uart_port *port = dev_id;
	struct tty_port *tport;
	unsigned long flags;

	spin_lock_irqsave(&port->lock, flags);
	tport = receive_chars(port);
	transmit_chars(port);
	spin_unlock_irqrestore(&port->lock, flags);

	if (tport)
		tty_flip_buffer_push(tport);

	return IRQ_HANDLED;
}

/* port->lock is not held.  */
static unsigned int sunhv_tx_empty(struct uart_port *port)
{
	/* Transmitter is always empty for us.  If the circ buffer
	 * is non-empty or there is an x_char pending, our caller
	 * will do the right thing and ignore what we return here.
	 */
	return TIOCSER_TEMT;
}

/* port->lock held by caller.  */
static void sunhv_set_mctrl(struct uart_port *port, unsigned int mctrl)
{
	return;
}

/* port->lock is held by caller and interrupts are disabled.  */
static unsigned int sunhv_get_mctrl(struct uart_port *port)
{
	return TIOCM_DSR | TIOCM_CAR | TIOCM_CTS;
}

/* port->lock held by caller.  */
static void sunhv_stop_tx(struct uart_port *port)
{
	return;
}

/* port->lock held by caller.  */
static void sunhv_start_tx(struct uart_port *port)
{
	transmit_chars(port);
}

/* port->lock is not held.  */
static void sunhv_send_xchar(struct uart_port *port, char ch)
{
	unsigned long flags;
	int limit = 10000;

	if (ch == __DISABLED_CHAR)
		return;

	spin_lock_irqsave(&port->lock, flags);

	while (limit-- > 0) {
		long status = sun4v_con_putchar(ch);
		if (status == HV_EOK)
			break;
		udelay(1);
	}

	spin_unlock_irqrestore(&port->lock, flags);
}

/* port->lock held by caller.  */
static void sunhv_stop_rx(struct uart_port *port)
{
}

/* port->lock is not held.  */
static void sunhv_break_ctl(struct uart_port *port, int break_state)
{
	if (break_state) {
		unsigned long flags;
		int limit = 10000;

		spin_lock_irqsave(&port->lock, flags);

		while (limit-- > 0) {
			long status = sun4v_con_putchar(CON_BREAK);
			if (status == HV_EOK)
				break;
			udelay(1);
		}

		spin_unlock_irqrestore(&port->lock, flags);
	}
}

/* port->lock is not held.  */
static int sunhv_startup(struct uart_port *port)
{
	return 0;
}

/* port->lock is not held.  */
static void sunhv_shutdown(struct uart_port *port)
{
}

/* port->lock is not held.  */
static void sunhv_set_termios(struct uart_port *port, struct ktermios *termios,
			      struct ktermios *old)
{
	unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
	unsigned int quot = uart_get_divisor(port, baud);
	unsigned int iflag, cflag;
	unsigned long flags;

	spin_lock_irqsave(&port->lock, flags);

	iflag = termios->c_iflag;
	cflag = termios->c_cflag;

	port->ignore_status_mask = 0;
	if (iflag & IGNBRK)
		port->ignore_status_mask |= IGNORE_BREAK;
	if ((cflag & CREAD) == 0)
		port->ignore_status_mask |= IGNORE_ALL;

	/* XXX */
	uart_update_timeout(port, cflag,
			    (port->uartclk / (16 * quot)));

	spin_unlock_irqrestore(&port->lock, flags);
}

static const char *sunhv_type(struct uart_port *port)
{
	return "SUN4V HCONS";
}

static void sunhv_release_port(struct uart_port *port)
{
}

static int sunhv_request_port(struct uart_port *port)
{
	return 0;
}

static void sunhv_config_port(struct uart_port *port, int flags)
{
}

static int sunhv_verify_port(struct uart_port *port, struct serial_struct *ser)
{
	return -EINVAL;
}

static struct uart_ops sunhv_pops = {
	.tx_empty	= sunhv_tx_empty,
	.set_mctrl	= sunhv_set_mctrl,
	.get_mctrl	= sunhv_get_mctrl,
	.stop_tx	= sunhv_stop_tx,
	.start_tx	= sunhv_start_tx,
	.send_xchar	= sunhv_send_xchar,
	.stop_rx	= sunhv_stop_rx,
	.break_ctl	= sunhv_break_ctl,
	.startup	= sunhv_startup,
	.shutdown	= sunhv_shutdown,
	.set_termios	= sunhv_set_termios,
	.type		= sunhv_type,
	.release_port	= sunhv_release_port,
	.request_port	= sunhv_request_port,
	.config_port	= sunhv_config_port,
	.verify_port	= sunhv_verify_port,
};

static struct uart_driver sunhv_reg = {
	.owner			= THIS_MODULE,
	.driver_name		= "sunhv",
	.dev_name		= "ttyS",
	.major			= TTY_MAJOR,
};

static struct uart_port *sunhv_port;

/* Copy 's' into the con_write_page, decoding "\n" into
 * "\r\n" along the way.  We have to return two lengths
 * because the caller needs to know how much to advance
 * 's' and also how many bytes to output via con_write_page.
 */
static int fill_con_write_page(const char *s, unsigned int n,
			       unsigned long *page_bytes)
{
	const char *orig_s = s;
	char *p = con_write_page;
	int left = PAGE_SIZE;

	while (n--) {
		if (*s == '\n') {
			if (left < 2)
				break;
			*p++ = '\r';
			left--;
		} else if (left < 1)
			break;
		*p++ = *s++;
		left--;
	}
	*page_bytes = p - con_write_page;
	return s - orig_s;
}

static void sunhv_console_write_paged(struct console *con, const char *s, unsigned n)
{
	struct uart_port *port = sunhv_port;
	unsigned long flags;
	int locked = 1;

	if (port->sysrq || oops_in_progress)
		locked = spin_trylock_irqsave(&port->lock, flags);
	else
		spin_lock_irqsave(&port->lock, flags);

	while (n > 0) {
		unsigned long ra = __pa(con_write_page);
		unsigned long page_bytes;
		unsigned int cpy = fill_con_write_page(s, n,
						       &page_bytes);

		n -= cpy;
		s += cpy;
		while (page_bytes > 0) {
			unsigned long written;
			int limit = 1000000;

			while (limit--) {
				unsigned long stat;

				stat = sun4v_con_write(ra, page_bytes,
						       &written);
				if (stat == HV_EOK)
					break;
				udelay(1);
			}
			if (limit < 0)
				break;
			page_bytes -= written;
			ra += written;
		}
	}

	if (locked)
		spin_unlock_irqrestore(&port->lock, flags);
}

static inline void sunhv_console_putchar(struct uart_port *port, char c)
{
	int limit = 1000000;

	while (limit-- > 0) {
		long status = sun4v_con_putchar(c);
		if (status == HV_EOK)
			break;
		udelay(1);
	}
}

static void sunhv_console_write_bychar(struct console *con, const char *s, unsigned n)
{
	struct uart_port *port = sunhv_port;
	unsigned long flags;
	int i, locked = 1;

	if (port->sysrq || oops_in_progress)
		locked = spin_trylock_irqsave(&port->lock, flags);
	else
		spin_lock_irqsave(&port->lock, flags);

	for (i = 0; i < n; i++) {
		if (*s == '\n')
			sunhv_console_putchar(port, '\r');
		sunhv_console_putchar(port, *s++);
	}

	if (locked)
		spin_unlock_irqrestore(&port->lock, flags);
}

static struct console sunhv_console = {
	.name	=	"ttyHV",
	.write	=	sunhv_console_write_bychar,
	.device	=	uart_console_device,
	.flags	=	CON_PRINTBUFFER,
	.index	=	-1,
	.data	=	&sunhv_reg,
};

static int hv_probe(struct platform_device *op)
{
	struct uart_port *port;
	unsigned long minor;
	int err;

	if (op->archdata.irqs[0] == 0xffffffff)
		return -ENODEV;

	port = kzalloc(sizeof(struct uart_port), GFP_KERNEL);
	if (unlikely(!port))
		return -ENOMEM;

	minor = 1;
	if (sun4v_hvapi_register(HV_GRP_CORE, 1, &minor) == 0 &&
	    minor >= 1) {
		err = -ENOMEM;
		con_write_page = kzalloc(PAGE_SIZE, GFP_KERNEL);
		if (!con_write_page)
			goto out_free_port;

		con_read_page = kzalloc(PAGE_SIZE, GFP_KERNEL);
		if (!con_read_page)
			goto out_free_con_write_page;

		sunhv_console.write = sunhv_console_write_paged;
		sunhv_ops = &bywrite_ops;
	}

	sunhv_port = port;

	port->line = 0;
	port->ops = &sunhv_pops;
	port->type = PORT_SUNHV;
	port->uartclk = ( 29491200 / 16 ); /* arbitrary */

	port->membase = (unsigned char __iomem *) __pa(port);

	port->irq = op->archdata.irqs[0];

	port->dev = &op->dev;

	err = sunserial_register_minors(&sunhv_reg, 1);
	if (err)
		goto out_free_con_read_page;

	sunserial_console_match(&sunhv_console, op->dev.of_node,
				&sunhv_reg, port->line, false);

	err = uart_add_one_port(&sunhv_reg, port);
	if (err)
		goto out_unregister_driver;

	err = request_irq(port->irq, sunhv_interrupt, 0, "hvcons", port);
	if (err)
		goto out_remove_port;

	platform_set_drvdata(op, port);

	return 0;

out_remove_port:
	uart_remove_one_port(&sunhv_reg, port);

out_unregister_driver:
	sunserial_unregister_minors(&sunhv_reg, 1);

out_free_con_read_page:
	kfree(con_read_page);

out_free_con_write_page:
	kfree(con_write_page);

out_free_port:
	kfree(port);
	sunhv_port = NULL;
	return err;
}

static int hv_remove(struct platform_device *dev)
{
	struct uart_port *port = platform_get_drvdata(dev);

	free_irq(port->irq, port);

	uart_remove_one_port(&sunhv_reg, port);

	sunserial_unregister_minors(&sunhv_reg, 1);

	kfree(port);
	sunhv_port = NULL;

	return 0;
}

static const struct of_device_id hv_match[] = {
	{
		.name = "console",
		.compatible = "qcn",
	},
	{
		.name = "console",
		.compatible = "SUNW,sun4v-console",
	},
	{},
};

static struct platform_driver hv_driver = {
	.driver = {
		.name = "hv",
		.of_match_table = hv_match,
	},
	.probe		= hv_probe,
	.remove		= hv_remove,
};

static int __init sunhv_init(void)
{
	if (tlb_type != hypervisor)
		return -ENODEV;

	return platform_driver_register(&hv_driver);
}
device_initcall(sunhv_init);

#if 0 /* ...def MODULE ; never supported as such */
MODULE_AUTHOR("David S. Miller");
MODULE_DESCRIPTION("SUN4V Hypervisor console driver");
MODULE_VERSION("2.0");
MODULE_LICENSE("GPL");
#endif
Commit	Line	Data
02fd473b DM	1	/* sunhv.c: Serial driver for SUN4V hypervisor console.
02fd473b DM	2	*
c7754d46	3	* Copyright (C) 2006, 2007 David S. Miller (davem@davemloft.net)
02fd473b DM	4	*/
02fd473b DM	5
02fd473b DM	6	#include <linux/kernel.h>
	7	#include <linux/errno.h>
	8	#include <linux/tty.h>
	9	#include <linux/tty_flip.h>
	10	#include <linux/major.h>
	11	#include <linux/circ_buf.h>
	12	#include <linux/serial.h>
	13	#include <linux/sysrq.h>
	14	#include <linux/console.h>
	15	#include <linux/spinlock.h>
	16	#include <linux/slab.h>
	17	#include <linux/delay.h>
	18	#include <linux/init.h>
c6ed413d	19	#include <linux/of_device.h>
02fd473b DM	20
	21	#include <asm/hypervisor.h>
	22	#include <asm/spitfire.h>
93872ba2	23	#include <asm/prom.h>
f4266ab4	24	#include <asm/irq.h>
d550bbd4	25	#include <asm/setup.h>
02fd473b DM	26
	27	#if defined(CONFIG_MAGIC_SYSRQ)
	28	#define SUPPORT_SYSRQ
	29	#endif
	30
	31	#include <linux/serial_core.h>
6816383a	32	#include <linux/sunserialcore.h>
02fd473b DM	33
	34	#define CON_BREAK ((long)-1)
	35	#define CON_HUP ((long)-2)
	36
c7754d46 DM	37	#define IGNORE_BREAK 0x1
c7754d46 DM	38	#define IGNORE_ALL 0x2
02fd473b	39
c7754d46 DM	40	static char *con_write_page;
c7754d46 DM	41	static char *con_read_page;
02fd473b	42
c7754d46	43	static int hung_up = 0;
02fd473b	44
c7754d46	45	static void transmit_chars_putchar(struct uart_port port, struct circ_buf xmit)
02fd473b	46	{
c7754d46 DM	47	while (!uart_circ_empty(xmit)) {
c7754d46 DM	48	long status = sun4v_con_putchar(xmit->buf[xmit->tail]);
02fd473b	49
c7754d46 DM	50	if (status != HV_EOK)
c7754d46 DM	51	break;
02fd473b	52
c7754d46 DM	53	xmit->tail = (xmit->tail + 1) & (UART_XMIT_SIZE - 1);
	54	port->icount.tx++;
	55	}
02fd473b DM	56	}
02fd473b DM	57
c7754d46 DM	58	static void transmit_chars_write(struct uart_port port, struct circ_buf xmit)
	59	{
	60	while (!uart_circ_empty(xmit)) {
	61	unsigned long ra = __pa(xmit->buf + xmit->tail);
	62	unsigned long len, status, sent;
02fd473b	63
c7754d46 DM	64	len = CIRC_CNT_TO_END(xmit->head, xmit->tail,
	65	UART_XMIT_SIZE);
	66	status = sun4v_con_write(ra, len, &sent);
	67	if (status != HV_EOK)
	68	break;
	69	xmit->tail = (xmit->tail + sent) & (UART_XMIT_SIZE - 1);
	70	port->icount.tx += sent;
	71	}
	72	}
02fd473b	73
05c7cd39	74	static int receive_chars_getchar(struct uart_port *port)
02fd473b	75	{
02fd473b DM	76	int saw_console_brk = 0;
	77	int limit = 10000;
	78
02fd473b DM	79	while (limit-- > 0) {
02fd473b DM	80	long status;
c7754d46	81	long c = sun4v_con_getchar(&status);
02fd473b DM	82
	83	if (status == HV_EWOULDBLOCK)
	84	break;
	85
	86	if (c == CON_BREAK) {
135066a2 DM	87	if (uart_handle_break(port))
135066a2 DM	88	continue;
02fd473b DM	89	saw_console_brk = 1;
	90	c = 0;
	91	}
	92
	93	if (c == CON_HUP) {
	94	hung_up = 1;
	95	uart_handle_dcd_change(port, 0);
	96	} else if (hung_up) {
	97	hung_up = 0;
	98	uart_handle_dcd_change(port, 1);
	99	}
	100
92a19f9c	101	if (port->state == NULL) {
7d12e780	102	uart_handle_sysrq_char(port, c);
02fd473b DM	103	continue;
	104	}
	105
02fd473b	106	port->icount.rx++;
02fd473b	107
7d12e780	108	if (uart_handle_sysrq_char(port, c))
02fd473b DM	109	continue;
02fd473b DM	110
92a19f9c	111	tty_insert_flip_char(&port->state->port, c, TTY_NORMAL);
c7754d46 DM	112	}
	113
	114	return saw_console_brk;
	115	}
	116
05c7cd39	117	static int receive_chars_read(struct uart_port *port)
c7754d46 DM	118	{
	119	int saw_console_brk = 0;
	120	int limit = 10000;
	121
	122	while (limit-- > 0) {
	123	unsigned long ra = __pa(con_read_page);
	124	unsigned long bytes_read, i;
	125	long stat = sun4v_con_read(ra, PAGE_SIZE, &bytes_read);
	126
	127	if (stat != HV_EOK) {
	128	bytes_read = 0;
	129
	130	if (stat == CON_BREAK) {
	131	if (uart_handle_break(port))
	132	continue;
	133	saw_console_brk = 1;
	134	*con_read_page = 0;
	135	bytes_read = 1;
	136	} else if (stat == CON_HUP) {
	137	hung_up = 1;
	138	uart_handle_dcd_change(port, 0);
	139	continue;
	140	} else {
	141	/* HV_EWOULDBLOCK, etc. */
	142	break;
	143	}
	144	}
	145
	146	if (hung_up) {
	147	hung_up = 0;
	148	uart_handle_dcd_change(port, 1);
	149	}
	150
079317a6 VK	151	if (port->sysrq != 0 && *con_read_page) {
	152	for (i = 0; i < bytes_read; i++)
	153	uart_handle_sysrq_char(port, con_read_page[i]);
	154	}
c7754d46	155
05c7cd39	156	if (port->state == NULL)
02fd473b DM	157	continue;
02fd473b DM	158
c7754d46 DM	159	port->icount.rx += bytes_read;
c7754d46 DM	160
05c7cd39 JS	161	tty_insert_flip_string(&port->state->port, con_read_page,
05c7cd39 JS	162	bytes_read);
02fd473b DM	163	}
02fd473b DM	164
c7754d46 DM	165	return saw_console_brk;
	166	}
	167
	168	struct sunhv_ops {
	169	void (transmit_chars)(struct uart_port port, struct circ_buf *xmit);
05c7cd39	170	int (receive_chars)(struct uart_port port);
c7754d46 DM	171	};
c7754d46 DM	172
01fd3c27	173	static const struct sunhv_ops bychar_ops = {
c7754d46 DM	174	.transmit_chars = transmit_chars_putchar,
	175	.receive_chars = receive_chars_getchar,
	176	};
	177
01fd3c27	178	static const struct sunhv_ops bywrite_ops = {
c7754d46 DM	179	.transmit_chars = transmit_chars_write,
	180	.receive_chars = receive_chars_read,
	181	};
	182
01fd3c27	183	static const struct sunhv_ops *sunhv_ops = &bychar_ops;
c7754d46	184
2e124b4a	185	static struct tty_port receive_chars(struct uart_port port)
c7754d46	186	{
2e124b4a	187	struct tty_port *tport = NULL;
c7754d46	188
ebd2c8f6	189	if (port->state != NULL) /* Unopened serial console */
2e124b4a	190	tport = &port->state->port;
c7754d46	191
05c7cd39	192	if (sunhv_ops->receive_chars(port))
02fd473b DM	193	sun_do_break();
02fd473b DM	194
2e124b4a	195	return tport;
02fd473b DM	196	}
	197
	198	static void transmit_chars(struct uart_port *port)
	199	{
db33f9bc DM	200	struct circ_buf *xmit;
db33f9bc DM	201
ebd2c8f6	202	if (!port->state)
db33f9bc	203	return;
02fd473b	204
ebd2c8f6	205	xmit = &port->state->xmit;
02fd473b DM	206	if (uart_circ_empty(xmit) \|\| uart_tx_stopped(port))
	207	return;
	208
c7754d46	209	sunhv_ops->transmit_chars(port, xmit);
02fd473b DM	210
	211	if (uart_circ_chars_pending(xmit) < WAKEUP_CHARS)
	212	uart_write_wakeup(port);
	213	}
	214
7d12e780	215	static irqreturn_t sunhv_interrupt(int irq, void *dev_id)
02fd473b DM	216	{
02fd473b DM	217	struct uart_port *port = dev_id;
2e124b4a	218	struct tty_port *tport;
02fd473b DM	219	unsigned long flags;
	220
	221	spin_lock_irqsave(&port->lock, flags);
2e124b4a	222	tport = receive_chars(port);
02fd473b DM	223	transmit_chars(port);
	224	spin_unlock_irqrestore(&port->lock, flags);
	225
2e124b4a JS	226	if (tport)
2e124b4a JS	227	tty_flip_buffer_push(tport);
02fd473b DM	228
	229	return IRQ_HANDLED;
	230	}
	231
	232	/* port->lock is not held. */
	233	static unsigned int sunhv_tx_empty(struct uart_port *port)
	234	{
	235	/* Transmitter is always empty for us. If the circ buffer
	236	* is non-empty or there is an x_char pending, our caller
	237	* will do the right thing and ignore what we return here.
	238	*/
	239	return TIOCSER_TEMT;
	240	}
	241
	242	/* port->lock held by caller. */
	243	static void sunhv_set_mctrl(struct uart_port *port, unsigned int mctrl)
	244	{
	245	return;
	246	}
	247
	248	/* port->lock is held by caller and interrupts are disabled. */
	249	static unsigned int sunhv_get_mctrl(struct uart_port *port)
	250	{
	251	return TIOCM_DSR \| TIOCM_CAR \| TIOCM_CTS;
	252	}
	253
	254	/* port->lock held by caller. */
	255	static void sunhv_stop_tx(struct uart_port *port)
	256	{
	257	return;
	258	}
	259
	260	/* port->lock held by caller. */
	261	static void sunhv_start_tx(struct uart_port *port)
	262	{
f798634d	263	transmit_chars(port);
02fd473b DM	264	}
	265
	266	/* port->lock is not held. */
	267	static void sunhv_send_xchar(struct uart_port *port, char ch)
	268	{
	269	unsigned long flags;
	270	int limit = 10000;
	271
db106df3 PH	272	if (ch == __DISABLED_CHAR)
	273	return;
	274
02fd473b DM	275	spin_lock_irqsave(&port->lock, flags);
	276
	277	while (limit-- > 0) {
c7754d46	278	long status = sun4v_con_putchar(ch);
02fd473b DM	279	if (status == HV_EOK)
02fd473b DM	280	break;
c7754d46	281	udelay(1);
02fd473b DM	282	}
	283
	284	spin_unlock_irqrestore(&port->lock, flags);
	285	}
	286
	287	/* port->lock held by caller. */
	288	static void sunhv_stop_rx(struct uart_port *port)
	289	{
	290	}
	291
02fd473b DM	292	/* port->lock is not held. */
	293	static void sunhv_break_ctl(struct uart_port *port, int break_state)
	294	{
	295	if (break_state) {
	296	unsigned long flags;
c7754d46	297	int limit = 10000;
02fd473b DM	298
	299	spin_lock_irqsave(&port->lock, flags);
	300
	301	while (limit-- > 0) {
c7754d46	302	long status = sun4v_con_putchar(CON_BREAK);
02fd473b DM	303	if (status == HV_EOK)
02fd473b DM	304	break;
c7754d46	305	udelay(1);
02fd473b DM	306	}
	307
	308	spin_unlock_irqrestore(&port->lock, flags);
	309	}
	310	}
	311
	312	/* port->lock is not held. */
	313	static int sunhv_startup(struct uart_port *port)
	314	{
	315	return 0;
	316	}
	317
	318	/* port->lock is not held. */
	319	static void sunhv_shutdown(struct uart_port *port)
	320	{
	321	}
	322
	323	/* port->lock is not held. */
606d099c AC	324	static void sunhv_set_termios(struct uart_port port, struct ktermios termios,
606d099c AC	325	struct ktermios *old)
02fd473b DM	326	{
	327	unsigned int baud = uart_get_baud_rate(port, termios, old, 0, 4000000);
	328	unsigned int quot = uart_get_divisor(port, baud);
	329	unsigned int iflag, cflag;
	330	unsigned long flags;
	331
	332	spin_lock_irqsave(&port->lock, flags);
	333
	334	iflag = termios->c_iflag;
	335	cflag = termios->c_cflag;
	336
	337	port->ignore_status_mask = 0;
	338	if (iflag & IGNBRK)
	339	port->ignore_status_mask \|= IGNORE_BREAK;
	340	if ((cflag & CREAD) == 0)
	341	port->ignore_status_mask \|= IGNORE_ALL;
	342
	343	/* XXX */
	344	uart_update_timeout(port, cflag,
	345	(port->uartclk / (16 * quot)));
	346
	347	spin_unlock_irqrestore(&port->lock, flags);
	348	}
	349
	350	static const char sunhv_type(struct uart_port port)
	351	{
	352	return "SUN4V HCONS";
	353	}
	354
	355	static void sunhv_release_port(struct uart_port *port)
	356	{
	357	}
	358
	359	static int sunhv_request_port(struct uart_port *port)
	360	{
	361	return 0;
	362	}
	363
	364	static void sunhv_config_port(struct uart_port *port, int flags)
	365	{
	366	}
	367
	368	static int sunhv_verify_port(struct uart_port port, struct serial_struct ser)
	369	{
	370	return -EINVAL;
	371	}
	372
	373	static struct uart_ops sunhv_pops = {
	374	.tx_empty = sunhv_tx_empty,
	375	.set_mctrl = sunhv_set_mctrl,
	376	.get_mctrl = sunhv_get_mctrl,
	377	.stop_tx = sunhv_stop_tx,
	378	.start_tx = sunhv_start_tx,
	379	.send_xchar = sunhv_send_xchar,
	380	.stop_rx = sunhv_stop_rx,
02fd473b DM	381	.break_ctl = sunhv_break_ctl,
	382	.startup = sunhv_startup,
	383	.shutdown = sunhv_shutdown,
	384	.set_termios = sunhv_set_termios,
	385	.type = sunhv_type,
	386	.release_port = sunhv_release_port,
	387	.request_port = sunhv_request_port,
	388	.config_port = sunhv_config_port,
	389	.verify_port = sunhv_verify_port,
	390	};
	391
	392	static struct uart_driver sunhv_reg = {
	393	.owner = THIS_MODULE,
32039f49	394	.driver_name = "sunhv",
02fd473b DM	395	.dev_name = "ttyS",
	396	.major = TTY_MAJOR,
	397	};
	398
	399	static struct uart_port *sunhv_port;
	400
c7754d46 DM	401	/* Copy 's' into the con_write_page, decoding "\n" into
	402	* "\r\n" along the way. We have to return two lengths
	403	* because the caller needs to know how much to advance
	404	* 's' and also how many bytes to output via con_write_page.
	405	*/
	406	static int fill_con_write_page(const char *s, unsigned int n,
	407	unsigned long *page_bytes)
	408	{
	409	const char *orig_s = s;
	410	char *p = con_write_page;
	411	int left = PAGE_SIZE;
	412
	413	while (n--) {
	414	if (*s == '\n') {
	415	if (left < 2)
	416	break;
	417	*p++ = '\r';
	418	left--;
	419	} else if (left < 1)
	420	break;
	421	p++ = s++;
	422	left--;
	423	}
	424	*page_bytes = p - con_write_page;
	425	return s - orig_s;
	426	}
	427
	428	static void sunhv_console_write_paged(struct console con, const char s, unsigned n)
02fd473b	429	{
c7754d46	430	struct uart_port *port = sunhv_port;
02fd473b	431	unsigned long flags;
f3c681c0 DM	432	int locked = 1;
f3c681c0 DM	433
e58e241c DM	434	if (port->sysrq \|\| oops_in_progress)
	435	locked = spin_trylock_irqsave(&port->lock, flags);
	436	else
	437	spin_lock_irqsave(&port->lock, flags);
02fd473b	438
c7754d46 DM	439	while (n > 0) {
	440	unsigned long ra = __pa(con_write_page);
	441	unsigned long page_bytes;
	442	unsigned int cpy = fill_con_write_page(s, n,
	443	&page_bytes);
	444
	445	n -= cpy;
	446	s += cpy;
	447	while (page_bytes > 0) {
	448	unsigned long written;
	449	int limit = 1000000;
	450
	451	while (limit--) {
	452	unsigned long stat;
	453
	454	stat = sun4v_con_write(ra, page_bytes,
	455	&written);
	456	if (stat == HV_EOK)
	457	break;
	458	udelay(1);
	459	}
52e3632e	460	if (limit < 0)
c7754d46 DM	461	break;
	462	page_bytes -= written;
	463	ra += written;
	464	}
	465	}
f3c681c0 DM	466
f3c681c0 DM	467	if (locked)
e58e241c	468	spin_unlock_irqrestore(&port->lock, flags);
c7754d46 DM	469	}
	470
	471	static inline void sunhv_console_putchar(struct uart_port *port, char c)
	472	{
	473	int limit = 1000000;
02fd473b DM	474
02fd473b DM	475	while (limit-- > 0) {
c7754d46	476	long status = sun4v_con_putchar(c);
02fd473b DM	477	if (status == HV_EOK)
02fd473b DM	478	break;
c7754d46	479	udelay(1);
02fd473b	480	}
02fd473b DM	481	}
02fd473b DM	482
c7754d46	483	static void sunhv_console_write_bychar(struct console con, const char s, unsigned n)
02fd473b DM	484	{
02fd473b DM	485	struct uart_port *port = sunhv_port;
c7754d46	486	unsigned long flags;
f3c681c0 DM	487	int i, locked = 1;
f3c681c0 DM	488
e58e241c DM	489	if (port->sysrq \|\| oops_in_progress)
	490	locked = spin_trylock_irqsave(&port->lock, flags);
	491	else
	492	spin_lock_irqsave(&port->lock, flags);
02fd473b DM	493
	494	for (i = 0; i < n; i++) {
	495	if (*s == '\n')
	496	sunhv_console_putchar(port, '\r');
	497	sunhv_console_putchar(port, *s++);
	498	}
f3c681c0 DM	499
f3c681c0 DM	500	if (locked)
e58e241c	501	spin_unlock_irqrestore(&port->lock, flags);
02fd473b DM	502	}
02fd473b DM	503
02fd473b	504	static struct console sunhv_console = {
d5a2aa24	505	.name = "ttyHV",
c7754d46	506	.write = sunhv_console_write_bychar,
02fd473b	507	.device = uart_console_device,
02fd473b DM	508	.flags = CON_PRINTBUFFER,
	509	.index = -1,
	510	.data = &sunhv_reg,
	511	};
	512
9671f099	513	static int hv_probe(struct platform_device *op)
02fd473b DM	514	{
02fd473b DM	515	struct uart_port *port;
c7754d46	516	unsigned long minor;
93872ba2	517	int err;
02fd473b	518
1636f8ac	519	if (op->archdata.irqs[0] == 0xffffffff)
02fd473b DM	520	return -ENODEV;
02fd473b DM	521
93872ba2	522	port = kzalloc(sizeof(struct uart_port), GFP_KERNEL);
02fd473b DM	523	if (unlikely(!port))
	524	return -ENOMEM;
	525
c7754d46 DM	526	minor = 1;
	527	if (sun4v_hvapi_register(HV_GRP_CORE, 1, &minor) == 0 &&
	528	minor >= 1) {
	529	err = -ENOMEM;
	530	con_write_page = kzalloc(PAGE_SIZE, GFP_KERNEL);
	531	if (!con_write_page)
	532	goto out_free_port;
	533
	534	con_read_page = kzalloc(PAGE_SIZE, GFP_KERNEL);
	535	if (!con_read_page)
	536	goto out_free_con_write_page;
	537
	538	sunhv_console.write = sunhv_console_write_paged;
	539	sunhv_ops = &bywrite_ops;
	540	}
	541
93872ba2	542	sunhv_port = port;
db33f9bc	543
02fd473b DM	544	port->line = 0;
	545	port->ops = &sunhv_pops;
	546	port->type = PORT_SUNHV;
	547	port->uartclk = ( 29491200 / 16 ); /* arbitrary */
	548
db33f9bc DM	549	port->membase = (unsigned char __iomem *) __pa(port);
db33f9bc DM	550
1636f8ac	551	port->irq = op->archdata.irqs[0];
93872ba2 DM	552
93872ba2 DM	553	port->dev = &op->dev;
02fd473b	554
58d784a5	555	err = sunserial_register_minors(&sunhv_reg, 1);
93872ba2	556	if (err)
c7754d46	557	goto out_free_con_read_page;
02fd473b	558
61c7a080	559	sunserial_console_match(&sunhv_console, op->dev.of_node,
457931de	560	&sunhv_reg, port->line, false);
d5a2aa24	561
93872ba2 DM	562	err = uart_add_one_port(&sunhv_reg, port);
	563	if (err)
	564	goto out_unregister_driver;
02fd473b	565
93872ba2 DM	566	err = request_irq(port->irq, sunhv_interrupt, 0, "hvcons", port);
	567	if (err)
	568	goto out_remove_port;
db33f9bc	569
696faedd	570	platform_set_drvdata(op, port);
02fd473b DM	571
02fd473b DM	572	return 0;
93872ba2 DM	573
	574	out_remove_port:
	575	uart_remove_one_port(&sunhv_reg, port);
	576
	577	out_unregister_driver:
58d784a5	578	sunserial_unregister_minors(&sunhv_reg, 1);
93872ba2	579
c7754d46 DM	580	out_free_con_read_page:
	581	kfree(con_read_page);
	582
	583	out_free_con_write_page:
	584	kfree(con_write_page);
	585
93872ba2 DM	586	out_free_port:
	587	kfree(port);
	588	sunhv_port = NULL;
	589	return err;
02fd473b DM	590	}
02fd473b DM	591
ae8d8a14	592	static int hv_remove(struct platform_device *dev)
02fd473b	593	{
696faedd	594	struct uart_port *port = platform_get_drvdata(dev);
02fd473b	595
db33f9bc DM	596	free_irq(port->irq, port);
db33f9bc DM	597
02fd473b	598	uart_remove_one_port(&sunhv_reg, port);
02fd473b	599
58d784a5	600	sunserial_unregister_minors(&sunhv_reg, 1);
02fd473b	601
93872ba2	602	kfree(port);
02fd473b	603	sunhv_port = NULL;
93872ba2	604
93872ba2 DM	605	return 0;
	606	}
	607
fd098316	608	static const struct of_device_id hv_match[] = {
93872ba2 DM	609	{
	610	.name = "console",
	611	.compatible = "qcn",
	612	},
7a05b591 DM	613	{
	614	.name = "console",
	615	.compatible = "SUNW,sun4v-console",
	616	},
93872ba2 DM	617	{},
93872ba2 DM	618	};
93872ba2	619
793218df	620	static struct platform_driver hv_driver = {
4018294b GL	621	.driver = {
4018294b GL	622	.name = "hv",
4018294b GL	623	.of_match_table = hv_match,
4018294b GL	624	},
93872ba2	625	.probe = hv_probe,
2d47b716	626	.remove = hv_remove,
93872ba2 DM	627	};
	628
	629	static int __init sunhv_init(void)
	630	{
	631	if (tlb_type != hypervisor)
	632	return -ENODEV;
	633
793218df	634	return platform_driver_register(&hv_driver);
93872ba2	635	}
4fef5351	636	device_initcall(sunhv_init);
93872ba2	637
4fef5351	638	#if 0 /* ...def MODULE ; never supported as such */
02fd473b	639	MODULE_AUTHOR("David S. Miller");
93872ba2 DM	640	MODULE_DESCRIPTION("SUN4V Hypervisor console driver");
93872ba2 DM	641	MODULE_VERSION("2.0");
02fd473b	642	MODULE_LICENSE("GPL");
4fef5351	643	#endif