cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
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ipoctal.c (19568B)


      1// SPDX-License-Identifier: GPL-2.0-only
      2/*
      3 * driver for the GE IP-OCTAL boards
      4 *
      5 * Copyright (C) 2009-2012 CERN (www.cern.ch)
      6 * Author: Nicolas Serafini, EIC2 SA
      7 * Author: Samuel Iglesias Gonsalvez <siglesias@igalia.com>
      8 */
      9
     10#include <linux/device.h>
     11#include <linux/module.h>
     12#include <linux/interrupt.h>
     13#include <linux/sched.h>
     14#include <linux/tty.h>
     15#include <linux/serial.h>
     16#include <linux/tty_flip.h>
     17#include <linux/slab.h>
     18#include <linux/io.h>
     19#include <linux/ipack.h>
     20#include "ipoctal.h"
     21#include "scc2698.h"
     22
     23#define IP_OCTAL_ID_SPACE_VECTOR    0x41
     24#define IP_OCTAL_NB_BLOCKS          4
     25
     26static const struct tty_operations ipoctal_fops;
     27
     28struct ipoctal_channel {
     29	struct ipoctal_stats		stats;
     30	unsigned int			nb_bytes;
     31	wait_queue_head_t		queue;
     32	spinlock_t			lock;
     33	unsigned int			pointer_read;
     34	unsigned int			pointer_write;
     35	struct tty_port			tty_port;
     36	bool				tty_registered;
     37	union scc2698_channel __iomem	*regs;
     38	union scc2698_block __iomem	*block_regs;
     39	unsigned int			board_id;
     40	u8				isr_rx_rdy_mask;
     41	u8				isr_tx_rdy_mask;
     42	unsigned int			rx_enable;
     43};
     44
     45struct ipoctal {
     46	struct ipack_device		*dev;
     47	unsigned int			board_id;
     48	struct ipoctal_channel		channel[NR_CHANNELS];
     49	struct tty_driver		*tty_drv;
     50	u8 __iomem			*mem8_space;
     51	u8 __iomem			*int_space;
     52};
     53
     54static inline struct ipoctal *chan_to_ipoctal(struct ipoctal_channel *chan,
     55					      unsigned int index)
     56{
     57	return container_of(chan, struct ipoctal, channel[index]);
     58}
     59
     60static void ipoctal_reset_channel(struct ipoctal_channel *channel)
     61{
     62	iowrite8(CR_DISABLE_RX | CR_DISABLE_TX, &channel->regs->w.cr);
     63	channel->rx_enable = 0;
     64	iowrite8(CR_CMD_RESET_RX, &channel->regs->w.cr);
     65	iowrite8(CR_CMD_RESET_TX, &channel->regs->w.cr);
     66	iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
     67	iowrite8(CR_CMD_RESET_MR, &channel->regs->w.cr);
     68}
     69
     70static int ipoctal_port_activate(struct tty_port *port, struct tty_struct *tty)
     71{
     72	struct ipoctal_channel *channel;
     73
     74	channel = dev_get_drvdata(tty->dev);
     75
     76	/*
     77	 * Enable RX. TX will be enabled when
     78	 * there is something to send
     79	 */
     80	iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
     81	channel->rx_enable = 1;
     82	return 0;
     83}
     84
     85static int ipoctal_install(struct tty_driver *driver, struct tty_struct *tty)
     86{
     87	struct ipoctal_channel *channel = dev_get_drvdata(tty->dev);
     88	struct ipoctal *ipoctal = chan_to_ipoctal(channel, tty->index);
     89	int res;
     90
     91	if (!ipack_get_carrier(ipoctal->dev))
     92		return -EBUSY;
     93
     94	res = tty_standard_install(driver, tty);
     95	if (res)
     96		goto err_put_carrier;
     97
     98	tty->driver_data = channel;
     99
    100	return 0;
    101
    102err_put_carrier:
    103	ipack_put_carrier(ipoctal->dev);
    104
    105	return res;
    106}
    107
    108static int ipoctal_open(struct tty_struct *tty, struct file *file)
    109{
    110	struct ipoctal_channel *channel = tty->driver_data;
    111
    112	return tty_port_open(&channel->tty_port, tty, file);
    113}
    114
    115static void ipoctal_reset_stats(struct ipoctal_stats *stats)
    116{
    117	stats->tx = 0;
    118	stats->rx = 0;
    119	stats->rcv_break = 0;
    120	stats->framing_err = 0;
    121	stats->overrun_err = 0;
    122	stats->parity_err = 0;
    123}
    124
    125static void ipoctal_free_channel(struct ipoctal_channel *channel)
    126{
    127	ipoctal_reset_stats(&channel->stats);
    128	channel->pointer_read = 0;
    129	channel->pointer_write = 0;
    130	channel->nb_bytes = 0;
    131}
    132
    133static void ipoctal_close(struct tty_struct *tty, struct file *filp)
    134{
    135	struct ipoctal_channel *channel = tty->driver_data;
    136
    137	tty_port_close(&channel->tty_port, tty, filp);
    138	ipoctal_free_channel(channel);
    139}
    140
    141static int ipoctal_get_icount(struct tty_struct *tty,
    142			      struct serial_icounter_struct *icount)
    143{
    144	struct ipoctal_channel *channel = tty->driver_data;
    145
    146	icount->cts = 0;
    147	icount->dsr = 0;
    148	icount->rng = 0;
    149	icount->dcd = 0;
    150	icount->rx = channel->stats.rx;
    151	icount->tx = channel->stats.tx;
    152	icount->frame = channel->stats.framing_err;
    153	icount->parity = channel->stats.parity_err;
    154	icount->brk = channel->stats.rcv_break;
    155	return 0;
    156}
    157
    158static void ipoctal_irq_rx(struct ipoctal_channel *channel, u8 sr)
    159{
    160	struct tty_port *port = &channel->tty_port;
    161	unsigned char value;
    162	unsigned char flag;
    163	u8 isr;
    164
    165	do {
    166		value = ioread8(&channel->regs->r.rhr);
    167		flag = TTY_NORMAL;
    168		/* Error: count statistics */
    169		if (sr & SR_ERROR) {
    170			iowrite8(CR_CMD_RESET_ERR_STATUS, &channel->regs->w.cr);
    171
    172			if (sr & SR_OVERRUN_ERROR) {
    173				channel->stats.overrun_err++;
    174				/* Overrun doesn't affect the current character*/
    175				tty_insert_flip_char(port, 0, TTY_OVERRUN);
    176			}
    177			if (sr & SR_PARITY_ERROR) {
    178				channel->stats.parity_err++;
    179				flag = TTY_PARITY;
    180			}
    181			if (sr & SR_FRAMING_ERROR) {
    182				channel->stats.framing_err++;
    183				flag = TTY_FRAME;
    184			}
    185			if (sr & SR_RECEIVED_BREAK) {
    186				channel->stats.rcv_break++;
    187				flag = TTY_BREAK;
    188			}
    189		}
    190		tty_insert_flip_char(port, value, flag);
    191
    192		/* Check if there are more characters in RX FIFO
    193		 * If there are more, the isr register for this channel
    194		 * has enabled the RxRDY|FFULL bit.
    195		 */
    196		isr = ioread8(&channel->block_regs->r.isr);
    197		sr = ioread8(&channel->regs->r.sr);
    198	} while (isr & channel->isr_rx_rdy_mask);
    199
    200	tty_flip_buffer_push(port);
    201}
    202
    203static void ipoctal_irq_tx(struct ipoctal_channel *channel)
    204{
    205	unsigned char value;
    206	unsigned int *pointer_write = &channel->pointer_write;
    207
    208	if (channel->nb_bytes == 0)
    209		return;
    210
    211	spin_lock(&channel->lock);
    212	value = channel->tty_port.xmit_buf[*pointer_write];
    213	iowrite8(value, &channel->regs->w.thr);
    214	channel->stats.tx++;
    215	(*pointer_write)++;
    216	*pointer_write = *pointer_write % PAGE_SIZE;
    217	channel->nb_bytes--;
    218	spin_unlock(&channel->lock);
    219}
    220
    221static void ipoctal_irq_channel(struct ipoctal_channel *channel)
    222{
    223	u8 isr, sr;
    224
    225	/* The HW is organized in pair of channels.  See which register we need
    226	 * to read from */
    227	isr = ioread8(&channel->block_regs->r.isr);
    228	sr = ioread8(&channel->regs->r.sr);
    229
    230	if (isr & (IMR_DELTA_BREAK_A | IMR_DELTA_BREAK_B))
    231		iowrite8(CR_CMD_RESET_BREAK_CHANGE, &channel->regs->w.cr);
    232
    233	if ((sr & SR_TX_EMPTY) && (channel->nb_bytes == 0)) {
    234		iowrite8(CR_DISABLE_TX, &channel->regs->w.cr);
    235		/* In case of RS-485, change from TX to RX when finishing TX.
    236		 * Half-duplex. */
    237		if (channel->board_id == IPACK1_DEVICE_ID_SBS_OCTAL_485) {
    238			iowrite8(CR_CMD_NEGATE_RTSN, &channel->regs->w.cr);
    239			iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
    240			channel->rx_enable = 1;
    241		}
    242	}
    243
    244	/* RX data */
    245	if ((isr & channel->isr_rx_rdy_mask) && (sr & SR_RX_READY))
    246		ipoctal_irq_rx(channel, sr);
    247
    248	/* TX of each character */
    249	if ((isr & channel->isr_tx_rdy_mask) && (sr & SR_TX_READY))
    250		ipoctal_irq_tx(channel);
    251}
    252
    253static irqreturn_t ipoctal_irq_handler(void *arg)
    254{
    255	unsigned int i;
    256	struct ipoctal *ipoctal = (struct ipoctal *) arg;
    257
    258	/* Clear the IPack device interrupt */
    259	readw(ipoctal->int_space + ACK_INT_REQ0);
    260	readw(ipoctal->int_space + ACK_INT_REQ1);
    261
    262	/* Check all channels */
    263	for (i = 0; i < NR_CHANNELS; i++)
    264		ipoctal_irq_channel(&ipoctal->channel[i]);
    265
    266	return IRQ_HANDLED;
    267}
    268
    269static const struct tty_port_operations ipoctal_tty_port_ops = {
    270	.dtr_rts = NULL,
    271	.activate = ipoctal_port_activate,
    272};
    273
    274static int ipoctal_inst_slot(struct ipoctal *ipoctal, unsigned int bus_nr,
    275			     unsigned int slot)
    276{
    277	int res;
    278	int i;
    279	struct tty_driver *drv;
    280	struct ipoctal_channel *channel;
    281	struct ipack_region *region;
    282	void __iomem *addr;
    283	union scc2698_channel __iomem *chan_regs;
    284	union scc2698_block __iomem *block_regs;
    285
    286	ipoctal->board_id = ipoctal->dev->id_device;
    287
    288	region = &ipoctal->dev->region[IPACK_IO_SPACE];
    289	addr = devm_ioremap(&ipoctal->dev->dev,
    290				    region->start, region->size);
    291	if (!addr) {
    292		dev_err(&ipoctal->dev->dev,
    293			"Unable to map slot [%d:%d] IO space!\n",
    294			bus_nr, slot);
    295		return -EADDRNOTAVAIL;
    296	}
    297	/* Save the virtual address to access the registers easily */
    298	chan_regs =
    299		(union scc2698_channel __iomem *) addr;
    300	block_regs =
    301		(union scc2698_block __iomem *) addr;
    302
    303	region = &ipoctal->dev->region[IPACK_INT_SPACE];
    304	ipoctal->int_space =
    305		devm_ioremap(&ipoctal->dev->dev,
    306				     region->start, region->size);
    307	if (!ipoctal->int_space) {
    308		dev_err(&ipoctal->dev->dev,
    309			"Unable to map slot [%d:%d] INT space!\n",
    310			bus_nr, slot);
    311		return -EADDRNOTAVAIL;
    312	}
    313
    314	region = &ipoctal->dev->region[IPACK_MEM8_SPACE];
    315	ipoctal->mem8_space =
    316		devm_ioremap(&ipoctal->dev->dev,
    317				     region->start, 0x8000);
    318	if (!ipoctal->mem8_space) {
    319		dev_err(&ipoctal->dev->dev,
    320			"Unable to map slot [%d:%d] MEM8 space!\n",
    321			bus_nr, slot);
    322		return -EADDRNOTAVAIL;
    323	}
    324
    325
    326	/* Disable RX and TX before touching anything */
    327	for (i = 0; i < NR_CHANNELS ; i++) {
    328		struct ipoctal_channel *channel = &ipoctal->channel[i];
    329		channel->regs = chan_regs + i;
    330		channel->block_regs = block_regs + (i >> 1);
    331		channel->board_id = ipoctal->board_id;
    332		if (i & 1) {
    333			channel->isr_tx_rdy_mask = ISR_TxRDY_B;
    334			channel->isr_rx_rdy_mask = ISR_RxRDY_FFULL_B;
    335		} else {
    336			channel->isr_tx_rdy_mask = ISR_TxRDY_A;
    337			channel->isr_rx_rdy_mask = ISR_RxRDY_FFULL_A;
    338		}
    339
    340		ipoctal_reset_channel(channel);
    341		iowrite8(MR1_CHRL_8_BITS | MR1_ERROR_CHAR | MR1_RxINT_RxRDY,
    342			 &channel->regs->w.mr); /* mr1 */
    343		iowrite8(0, &channel->regs->w.mr); /* mr2 */
    344		iowrite8(TX_CLK_9600  | RX_CLK_9600, &channel->regs->w.csr);
    345	}
    346
    347	for (i = 0; i < IP_OCTAL_NB_BLOCKS; i++) {
    348		iowrite8(ACR_BRG_SET2, &block_regs[i].w.acr);
    349		iowrite8(OPCR_MPP_OUTPUT | OPCR_MPOa_RTSN | OPCR_MPOb_RTSN,
    350			 &block_regs[i].w.opcr);
    351		iowrite8(IMR_TxRDY_A | IMR_RxRDY_FFULL_A | IMR_DELTA_BREAK_A |
    352			 IMR_TxRDY_B | IMR_RxRDY_FFULL_B | IMR_DELTA_BREAK_B,
    353			 &block_regs[i].w.imr);
    354	}
    355
    356	/* Dummy write */
    357	iowrite8(1, ipoctal->mem8_space + 1);
    358
    359	/* Register the TTY device */
    360
    361	/* Each IP-OCTAL channel is a TTY port */
    362	drv = tty_alloc_driver(NR_CHANNELS, TTY_DRIVER_REAL_RAW |
    363			TTY_DRIVER_DYNAMIC_DEV);
    364	if (IS_ERR(drv))
    365		return PTR_ERR(drv);
    366
    367	/* Fill struct tty_driver with ipoctal data */
    368	drv->owner = THIS_MODULE;
    369	drv->driver_name = KBUILD_MODNAME;
    370	drv->name = kasprintf(GFP_KERNEL, KBUILD_MODNAME ".%d.%d.", bus_nr, slot);
    371	if (!drv->name) {
    372		res = -ENOMEM;
    373		goto err_put_driver;
    374	}
    375	drv->major = 0;
    376
    377	drv->minor_start = 0;
    378	drv->type = TTY_DRIVER_TYPE_SERIAL;
    379	drv->subtype = SERIAL_TYPE_NORMAL;
    380	drv->init_termios = tty_std_termios;
    381	drv->init_termios.c_cflag = B9600 | CS8 | CREAD | HUPCL | CLOCAL;
    382	drv->init_termios.c_ispeed = 9600;
    383	drv->init_termios.c_ospeed = 9600;
    384
    385	tty_set_operations(drv, &ipoctal_fops);
    386	res = tty_register_driver(drv);
    387	if (res) {
    388		dev_err(&ipoctal->dev->dev, "Can't register tty driver.\n");
    389		goto err_free_name;
    390	}
    391
    392	/* Save struct tty_driver for use it when uninstalling the device */
    393	ipoctal->tty_drv = drv;
    394
    395	for (i = 0; i < NR_CHANNELS; i++) {
    396		struct device *tty_dev;
    397
    398		channel = &ipoctal->channel[i];
    399		tty_port_init(&channel->tty_port);
    400		res = tty_port_alloc_xmit_buf(&channel->tty_port);
    401		if (res)
    402			continue;
    403		channel->tty_port.ops = &ipoctal_tty_port_ops;
    404
    405		ipoctal_reset_stats(&channel->stats);
    406		channel->nb_bytes = 0;
    407		spin_lock_init(&channel->lock);
    408		channel->pointer_read = 0;
    409		channel->pointer_write = 0;
    410		tty_dev = tty_port_register_device_attr(&channel->tty_port, drv,
    411							i, NULL, channel, NULL);
    412		if (IS_ERR(tty_dev)) {
    413			dev_err(&ipoctal->dev->dev, "Failed to register tty device.\n");
    414			tty_port_free_xmit_buf(&channel->tty_port);
    415			tty_port_destroy(&channel->tty_port);
    416			continue;
    417		}
    418		channel->tty_registered = true;
    419	}
    420
    421	/*
    422	 * IP-OCTAL has different addresses to copy its IRQ vector.
    423	 * Depending of the carrier these addresses are accesible or not.
    424	 * More info in the datasheet.
    425	 */
    426	ipoctal->dev->bus->ops->request_irq(ipoctal->dev,
    427				       ipoctal_irq_handler, ipoctal);
    428
    429	return 0;
    430
    431err_free_name:
    432	kfree(drv->name);
    433err_put_driver:
    434	tty_driver_kref_put(drv);
    435
    436	return res;
    437}
    438
    439static inline int ipoctal_copy_write_buffer(struct ipoctal_channel *channel,
    440					    const unsigned char *buf,
    441					    int count)
    442{
    443	unsigned long flags;
    444	int i;
    445	unsigned int *pointer_read = &channel->pointer_read;
    446
    447	/* Copy the bytes from the user buffer to the internal one */
    448	for (i = 0; i < count; i++) {
    449		if (i <= (PAGE_SIZE - channel->nb_bytes)) {
    450			spin_lock_irqsave(&channel->lock, flags);
    451			channel->tty_port.xmit_buf[*pointer_read] = buf[i];
    452			*pointer_read = (*pointer_read + 1) % PAGE_SIZE;
    453			channel->nb_bytes++;
    454			spin_unlock_irqrestore(&channel->lock, flags);
    455		} else {
    456			break;
    457		}
    458	}
    459	return i;
    460}
    461
    462static int ipoctal_write_tty(struct tty_struct *tty,
    463			     const unsigned char *buf, int count)
    464{
    465	struct ipoctal_channel *channel = tty->driver_data;
    466	unsigned int char_copied;
    467
    468	char_copied = ipoctal_copy_write_buffer(channel, buf, count);
    469
    470	/* As the IP-OCTAL 485 only supports half duplex, do it manually */
    471	if (channel->board_id == IPACK1_DEVICE_ID_SBS_OCTAL_485) {
    472		iowrite8(CR_DISABLE_RX, &channel->regs->w.cr);
    473		channel->rx_enable = 0;
    474		iowrite8(CR_CMD_ASSERT_RTSN, &channel->regs->w.cr);
    475	}
    476
    477	/*
    478	 * Send a packet and then disable TX to avoid failure after several send
    479	 * operations
    480	 */
    481	iowrite8(CR_ENABLE_TX, &channel->regs->w.cr);
    482	return char_copied;
    483}
    484
    485static unsigned int ipoctal_write_room(struct tty_struct *tty)
    486{
    487	struct ipoctal_channel *channel = tty->driver_data;
    488
    489	return PAGE_SIZE - channel->nb_bytes;
    490}
    491
    492static unsigned int ipoctal_chars_in_buffer(struct tty_struct *tty)
    493{
    494	struct ipoctal_channel *channel = tty->driver_data;
    495
    496	return channel->nb_bytes;
    497}
    498
    499static void ipoctal_set_termios(struct tty_struct *tty,
    500				struct ktermios *old_termios)
    501{
    502	unsigned int cflag;
    503	unsigned char mr1 = 0;
    504	unsigned char mr2 = 0;
    505	unsigned char csr = 0;
    506	struct ipoctal_channel *channel = tty->driver_data;
    507	speed_t baud;
    508
    509	cflag = tty->termios.c_cflag;
    510
    511	/* Disable and reset everything before change the setup */
    512	ipoctal_reset_channel(channel);
    513
    514	/* Set Bits per chars */
    515	switch (cflag & CSIZE) {
    516	case CS6:
    517		mr1 |= MR1_CHRL_6_BITS;
    518		break;
    519	case CS7:
    520		mr1 |= MR1_CHRL_7_BITS;
    521		break;
    522	case CS8:
    523	default:
    524		mr1 |= MR1_CHRL_8_BITS;
    525		/* By default, select CS8 */
    526		tty->termios.c_cflag = (cflag & ~CSIZE) | CS8;
    527		break;
    528	}
    529
    530	/* Set Parity */
    531	if (cflag & PARENB)
    532		if (cflag & PARODD)
    533			mr1 |= MR1_PARITY_ON | MR1_PARITY_ODD;
    534		else
    535			mr1 |= MR1_PARITY_ON | MR1_PARITY_EVEN;
    536	else
    537		mr1 |= MR1_PARITY_OFF;
    538
    539	/* Mark or space parity is not supported */
    540	tty->termios.c_cflag &= ~CMSPAR;
    541
    542	/* Set stop bits */
    543	if (cflag & CSTOPB)
    544		mr2 |= MR2_STOP_BITS_LENGTH_2;
    545	else
    546		mr2 |= MR2_STOP_BITS_LENGTH_1;
    547
    548	/* Set the flow control */
    549	switch (channel->board_id) {
    550	case IPACK1_DEVICE_ID_SBS_OCTAL_232:
    551		if (cflag & CRTSCTS) {
    552			mr1 |= MR1_RxRTS_CONTROL_ON;
    553			mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_ON;
    554		} else {
    555			mr1 |= MR1_RxRTS_CONTROL_OFF;
    556			mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_OFF;
    557		}
    558		break;
    559	case IPACK1_DEVICE_ID_SBS_OCTAL_422:
    560		mr1 |= MR1_RxRTS_CONTROL_OFF;
    561		mr2 |= MR2_TxRTS_CONTROL_OFF | MR2_CTS_ENABLE_TX_OFF;
    562		break;
    563	case IPACK1_DEVICE_ID_SBS_OCTAL_485:
    564		mr1 |= MR1_RxRTS_CONTROL_OFF;
    565		mr2 |= MR2_TxRTS_CONTROL_ON | MR2_CTS_ENABLE_TX_OFF;
    566		break;
    567	default:
    568		return;
    569	}
    570
    571	baud = tty_get_baud_rate(tty);
    572	tty_termios_encode_baud_rate(&tty->termios, baud, baud);
    573
    574	/* Set baud rate */
    575	switch (baud) {
    576	case 75:
    577		csr |= TX_CLK_75 | RX_CLK_75;
    578		break;
    579	case 110:
    580		csr |= TX_CLK_110 | RX_CLK_110;
    581		break;
    582	case 150:
    583		csr |= TX_CLK_150 | RX_CLK_150;
    584		break;
    585	case 300:
    586		csr |= TX_CLK_300 | RX_CLK_300;
    587		break;
    588	case 600:
    589		csr |= TX_CLK_600 | RX_CLK_600;
    590		break;
    591	case 1200:
    592		csr |= TX_CLK_1200 | RX_CLK_1200;
    593		break;
    594	case 1800:
    595		csr |= TX_CLK_1800 | RX_CLK_1800;
    596		break;
    597	case 2000:
    598		csr |= TX_CLK_2000 | RX_CLK_2000;
    599		break;
    600	case 2400:
    601		csr |= TX_CLK_2400 | RX_CLK_2400;
    602		break;
    603	case 4800:
    604		csr |= TX_CLK_4800  | RX_CLK_4800;
    605		break;
    606	case 9600:
    607		csr |= TX_CLK_9600  | RX_CLK_9600;
    608		break;
    609	case 19200:
    610		csr |= TX_CLK_19200 | RX_CLK_19200;
    611		break;
    612	case 38400:
    613	default:
    614		csr |= TX_CLK_38400 | RX_CLK_38400;
    615		/* In case of default, we establish 38400 bps */
    616		tty_termios_encode_baud_rate(&tty->termios, 38400, 38400);
    617		break;
    618	}
    619
    620	mr1 |= MR1_ERROR_CHAR;
    621	mr1 |= MR1_RxINT_RxRDY;
    622
    623	/* Write the control registers */
    624	iowrite8(mr1, &channel->regs->w.mr);
    625	iowrite8(mr2, &channel->regs->w.mr);
    626	iowrite8(csr, &channel->regs->w.csr);
    627
    628	/* Enable again the RX, if it was before */
    629	if (channel->rx_enable)
    630		iowrite8(CR_ENABLE_RX, &channel->regs->w.cr);
    631}
    632
    633static void ipoctal_hangup(struct tty_struct *tty)
    634{
    635	unsigned long flags;
    636	struct ipoctal_channel *channel = tty->driver_data;
    637
    638	if (channel == NULL)
    639		return;
    640
    641	spin_lock_irqsave(&channel->lock, flags);
    642	channel->nb_bytes = 0;
    643	channel->pointer_read = 0;
    644	channel->pointer_write = 0;
    645	spin_unlock_irqrestore(&channel->lock, flags);
    646
    647	tty_port_hangup(&channel->tty_port);
    648
    649	ipoctal_reset_channel(channel);
    650	tty_port_set_initialized(&channel->tty_port, 0);
    651	wake_up_interruptible(&channel->tty_port.open_wait);
    652}
    653
    654static void ipoctal_shutdown(struct tty_struct *tty)
    655{
    656	struct ipoctal_channel *channel = tty->driver_data;
    657
    658	if (channel == NULL)
    659		return;
    660
    661	ipoctal_reset_channel(channel);
    662	tty_port_set_initialized(&channel->tty_port, 0);
    663}
    664
    665static void ipoctal_cleanup(struct tty_struct *tty)
    666{
    667	struct ipoctal_channel *channel = tty->driver_data;
    668	struct ipoctal *ipoctal = chan_to_ipoctal(channel, tty->index);
    669
    670	/* release the carrier driver */
    671	ipack_put_carrier(ipoctal->dev);
    672}
    673
    674static const struct tty_operations ipoctal_fops = {
    675	.ioctl =		NULL,
    676	.install =		ipoctal_install,
    677	.open =			ipoctal_open,
    678	.close =		ipoctal_close,
    679	.write =		ipoctal_write_tty,
    680	.set_termios =		ipoctal_set_termios,
    681	.write_room =		ipoctal_write_room,
    682	.chars_in_buffer =	ipoctal_chars_in_buffer,
    683	.get_icount =		ipoctal_get_icount,
    684	.hangup =		ipoctal_hangup,
    685	.shutdown =		ipoctal_shutdown,
    686	.cleanup =              ipoctal_cleanup,
    687};
    688
    689static int ipoctal_probe(struct ipack_device *dev)
    690{
    691	int res;
    692	struct ipoctal *ipoctal;
    693
    694	ipoctal = kzalloc(sizeof(struct ipoctal), GFP_KERNEL);
    695	if (ipoctal == NULL)
    696		return -ENOMEM;
    697
    698	ipoctal->dev = dev;
    699	res = ipoctal_inst_slot(ipoctal, dev->bus->bus_nr, dev->slot);
    700	if (res)
    701		goto out_uninst;
    702
    703	dev_set_drvdata(&dev->dev, ipoctal);
    704	return 0;
    705
    706out_uninst:
    707	kfree(ipoctal);
    708	return res;
    709}
    710
    711static void __ipoctal_remove(struct ipoctal *ipoctal)
    712{
    713	int i;
    714
    715	ipoctal->dev->bus->ops->free_irq(ipoctal->dev);
    716
    717	for (i = 0; i < NR_CHANNELS; i++) {
    718		struct ipoctal_channel *channel = &ipoctal->channel[i];
    719
    720		if (!channel->tty_registered)
    721			continue;
    722
    723		tty_unregister_device(ipoctal->tty_drv, i);
    724		tty_port_free_xmit_buf(&channel->tty_port);
    725		tty_port_destroy(&channel->tty_port);
    726	}
    727
    728	tty_unregister_driver(ipoctal->tty_drv);
    729	kfree(ipoctal->tty_drv->name);
    730	tty_driver_kref_put(ipoctal->tty_drv);
    731	kfree(ipoctal);
    732}
    733
    734static void ipoctal_remove(struct ipack_device *idev)
    735{
    736	__ipoctal_remove(dev_get_drvdata(&idev->dev));
    737}
    738
    739static DEFINE_IPACK_DEVICE_TABLE(ipoctal_ids) = {
    740	{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
    741			IPACK1_DEVICE_ID_SBS_OCTAL_232) },
    742	{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
    743			IPACK1_DEVICE_ID_SBS_OCTAL_422) },
    744	{ IPACK_DEVICE(IPACK_ID_VERSION_1, IPACK1_VENDOR_ID_SBS,
    745			IPACK1_DEVICE_ID_SBS_OCTAL_485) },
    746	{ 0, },
    747};
    748
    749MODULE_DEVICE_TABLE(ipack, ipoctal_ids);
    750
    751static const struct ipack_driver_ops ipoctal_drv_ops = {
    752	.probe  = ipoctal_probe,
    753	.remove = ipoctal_remove,
    754};
    755
    756static struct ipack_driver driver = {
    757	.ops      = &ipoctal_drv_ops,
    758	.id_table = ipoctal_ids,
    759};
    760
    761static int __init ipoctal_init(void)
    762{
    763	return ipack_driver_register(&driver, THIS_MODULE, KBUILD_MODNAME);
    764}
    765
    766static void __exit ipoctal_exit(void)
    767{
    768	ipack_driver_unregister(&driver);
    769}
    770
    771MODULE_DESCRIPTION("IP-Octal 232, 422 and 485 device driver");
    772MODULE_LICENSE("GPL");
    773
    774module_init(ipoctal_init);
    775module_exit(ipoctal_exit);