cachepc-linux

Fork of AMDESE/linux with modifications for CachePC side-channel attack
git clone https://git.sinitax.com/sinitax/cachepc-linux
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ssu100.c (12948B)


      1// SPDX-License-Identifier: GPL-2.0
      2/*
      3 * usb-serial driver for Quatech SSU-100
      4 *
      5 * based on ftdi_sio.c and the original serqt_usb.c from Quatech
      6 *
      7 */
      8
      9#include <linux/errno.h>
     10#include <linux/slab.h>
     11#include <linux/tty.h>
     12#include <linux/tty_driver.h>
     13#include <linux/tty_flip.h>
     14#include <linux/module.h>
     15#include <linux/serial.h>
     16#include <linux/usb.h>
     17#include <linux/usb/serial.h>
     18#include <linux/serial_reg.h>
     19#include <linux/uaccess.h>
     20
     21#define QT_OPEN_CLOSE_CHANNEL       0xca
     22#define QT_SET_GET_DEVICE           0xc2
     23#define QT_SET_GET_REGISTER         0xc0
     24#define QT_GET_SET_PREBUF_TRIG_LVL  0xcc
     25#define QT_SET_ATF                  0xcd
     26#define QT_GET_SET_UART             0xc1
     27#define QT_TRANSFER_IN              0xc0
     28#define QT_HW_FLOW_CONTROL_MASK     0xc5
     29#define QT_SW_FLOW_CONTROL_MASK     0xc6
     30
     31#define  SERIAL_MSR_MASK            0xf0
     32
     33#define  SERIAL_CRTSCTS ((UART_MCR_RTS << 8) | UART_MSR_CTS)
     34
     35#define  SERIAL_EVEN_PARITY         (UART_LCR_PARITY | UART_LCR_EPAR)
     36
     37#define  MAX_BAUD_RATE              460800
     38
     39#define ATC_DISABLED                0x00
     40#define DUPMODE_BITS        0xc0
     41#define RR_BITS             0x03
     42#define LOOPMODE_BITS       0x41
     43#define RS232_MODE          0x00
     44#define RTSCTS_TO_CONNECTOR 0x40
     45#define CLKS_X4             0x02
     46#define FULLPWRBIT          0x00000080
     47#define NEXT_BOARD_POWER_BIT        0x00000004
     48
     49#define DRIVER_DESC "Quatech SSU-100 USB to Serial Driver"
     50
     51#define	USB_VENDOR_ID_QUATECH	0x061d	/* Quatech VID */
     52#define QUATECH_SSU100	0xC020	/* SSU100 */
     53
     54static const struct usb_device_id id_table[] = {
     55	{USB_DEVICE(USB_VENDOR_ID_QUATECH, QUATECH_SSU100)},
     56	{}			/* Terminating entry */
     57};
     58MODULE_DEVICE_TABLE(usb, id_table);
     59
     60struct ssu100_port_private {
     61	spinlock_t status_lock;
     62	u8 shadowLSR;
     63	u8 shadowMSR;
     64};
     65
     66static inline int ssu100_control_msg(struct usb_device *dev,
     67				     u8 request, u16 data, u16 index)
     68{
     69	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
     70			       request, 0x40, data, index,
     71			       NULL, 0, 300);
     72}
     73
     74static inline int ssu100_setdevice(struct usb_device *dev, u8 *data)
     75{
     76	u16 x = ((u16)(data[1] << 8) | (u16)(data[0]));
     77
     78	return ssu100_control_msg(dev, QT_SET_GET_DEVICE, x, 0);
     79}
     80
     81
     82static inline int ssu100_getdevice(struct usb_device *dev, u8 *data)
     83{
     84	int ret;
     85
     86	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
     87			      QT_SET_GET_DEVICE, 0xc0, 0, 0,
     88			      data, 3, 300);
     89	if (ret < 3) {
     90		if (ret >= 0)
     91			ret = -EIO;
     92	}
     93
     94	return ret;
     95}
     96
     97static inline int ssu100_getregister(struct usb_device *dev,
     98				     unsigned short uart,
     99				     unsigned short reg,
    100				     u8 *data)
    101{
    102	int ret;
    103
    104	ret = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
    105			      QT_SET_GET_REGISTER, 0xc0, reg,
    106			      uart, data, sizeof(*data), 300);
    107	if (ret < (int)sizeof(*data)) {
    108		if (ret >= 0)
    109			ret = -EIO;
    110	}
    111
    112	return ret;
    113}
    114
    115
    116static inline int ssu100_setregister(struct usb_device *dev,
    117				     unsigned short uart,
    118				     unsigned short reg,
    119				     u16 data)
    120{
    121	u16 value = (data << 8) | reg;
    122
    123	return usb_control_msg(dev, usb_sndctrlpipe(dev, 0),
    124			       QT_SET_GET_REGISTER, 0x40, value, uart,
    125			       NULL, 0, 300);
    126
    127}
    128
    129#define set_mctrl(dev, set)		update_mctrl((dev), (set), 0)
    130#define clear_mctrl(dev, clear)	update_mctrl((dev), 0, (clear))
    131
    132/* these do not deal with device that have more than 1 port */
    133static inline int update_mctrl(struct usb_device *dev, unsigned int set,
    134			       unsigned int clear)
    135{
    136	unsigned urb_value;
    137	int result;
    138
    139	if (((set | clear) & (TIOCM_DTR | TIOCM_RTS)) == 0) {
    140		dev_dbg(&dev->dev, "%s - DTR|RTS not being set|cleared\n", __func__);
    141		return 0;	/* no change */
    142	}
    143
    144	clear &= ~set;	/* 'set' takes precedence over 'clear' */
    145	urb_value = 0;
    146	if (set & TIOCM_DTR)
    147		urb_value |= UART_MCR_DTR;
    148	if (set & TIOCM_RTS)
    149		urb_value |= UART_MCR_RTS;
    150
    151	result = ssu100_setregister(dev, 0, UART_MCR, urb_value);
    152	if (result < 0)
    153		dev_dbg(&dev->dev, "%s Error from MODEM_CTRL urb\n", __func__);
    154
    155	return result;
    156}
    157
    158static int ssu100_initdevice(struct usb_device *dev)
    159{
    160	u8 *data;
    161	int result = 0;
    162
    163	data = kzalloc(3, GFP_KERNEL);
    164	if (!data)
    165		return -ENOMEM;
    166
    167	result = ssu100_getdevice(dev, data);
    168	if (result < 0) {
    169		dev_dbg(&dev->dev, "%s - get_device failed %i\n", __func__, result);
    170		goto out;
    171	}
    172
    173	data[1] &= ~FULLPWRBIT;
    174
    175	result = ssu100_setdevice(dev, data);
    176	if (result < 0) {
    177		dev_dbg(&dev->dev, "%s - setdevice failed %i\n", __func__, result);
    178		goto out;
    179	}
    180
    181	result = ssu100_control_msg(dev, QT_GET_SET_PREBUF_TRIG_LVL, 128, 0);
    182	if (result < 0) {
    183		dev_dbg(&dev->dev, "%s - set prebuffer level failed %i\n", __func__, result);
    184		goto out;
    185	}
    186
    187	result = ssu100_control_msg(dev, QT_SET_ATF, ATC_DISABLED, 0);
    188	if (result < 0) {
    189		dev_dbg(&dev->dev, "%s - set ATFprebuffer level failed %i\n", __func__, result);
    190		goto out;
    191	}
    192
    193	result = ssu100_getdevice(dev, data);
    194	if (result < 0) {
    195		dev_dbg(&dev->dev, "%s - get_device failed %i\n", __func__, result);
    196		goto out;
    197	}
    198
    199	data[0] &= ~(RR_BITS | DUPMODE_BITS);
    200	data[0] |= CLKS_X4;
    201	data[1] &= ~(LOOPMODE_BITS);
    202	data[1] |= RS232_MODE;
    203
    204	result = ssu100_setdevice(dev, data);
    205	if (result < 0) {
    206		dev_dbg(&dev->dev, "%s - setdevice failed %i\n", __func__, result);
    207		goto out;
    208	}
    209
    210out:	kfree(data);
    211	return result;
    212
    213}
    214
    215
    216static void ssu100_set_termios(struct tty_struct *tty,
    217			       struct usb_serial_port *port,
    218			       struct ktermios *old_termios)
    219{
    220	struct usb_device *dev = port->serial->dev;
    221	struct ktermios *termios = &tty->termios;
    222	u16 baud, divisor, remainder;
    223	unsigned int cflag = termios->c_cflag;
    224	u16 urb_value = 0; /* will hold the new flags */
    225	int result;
    226
    227	if (cflag & PARENB) {
    228		if (cflag & PARODD)
    229			urb_value |= UART_LCR_PARITY;
    230		else
    231			urb_value |= SERIAL_EVEN_PARITY;
    232	}
    233
    234	urb_value |= UART_LCR_WLEN(tty_get_char_size(cflag));
    235
    236	baud = tty_get_baud_rate(tty);
    237	if (!baud)
    238		baud = 9600;
    239
    240	dev_dbg(&port->dev, "%s - got baud = %d\n", __func__, baud);
    241
    242
    243	divisor = MAX_BAUD_RATE / baud;
    244	remainder = MAX_BAUD_RATE % baud;
    245	if (((remainder * 2) >= baud) && (baud != 110))
    246		divisor++;
    247
    248	urb_value = urb_value << 8;
    249
    250	result = ssu100_control_msg(dev, QT_GET_SET_UART, divisor, urb_value);
    251	if (result < 0)
    252		dev_dbg(&port->dev, "%s - set uart failed\n", __func__);
    253
    254	if (cflag & CRTSCTS)
    255		result = ssu100_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
    256					    SERIAL_CRTSCTS, 0);
    257	else
    258		result = ssu100_control_msg(dev, QT_HW_FLOW_CONTROL_MASK,
    259					    0, 0);
    260	if (result < 0)
    261		dev_dbg(&port->dev, "%s - set HW flow control failed\n", __func__);
    262
    263	if (I_IXOFF(tty) || I_IXON(tty)) {
    264		u16 x = ((u16)(START_CHAR(tty) << 8) | (u16)(STOP_CHAR(tty)));
    265
    266		result = ssu100_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
    267					    x, 0);
    268	} else
    269		result = ssu100_control_msg(dev, QT_SW_FLOW_CONTROL_MASK,
    270					    0, 0);
    271
    272	if (result < 0)
    273		dev_dbg(&port->dev, "%s - set SW flow control failed\n", __func__);
    274
    275}
    276
    277
    278static int ssu100_open(struct tty_struct *tty, struct usb_serial_port *port)
    279{
    280	struct usb_device *dev = port->serial->dev;
    281	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
    282	u8 *data;
    283	int result;
    284	unsigned long flags;
    285
    286	data = kzalloc(2, GFP_KERNEL);
    287	if (!data)
    288		return -ENOMEM;
    289
    290	result = usb_control_msg(dev, usb_rcvctrlpipe(dev, 0),
    291				 QT_OPEN_CLOSE_CHANNEL,
    292				 QT_TRANSFER_IN, 0x01,
    293				 0, data, 2, 300);
    294	if (result < 2) {
    295		dev_dbg(&port->dev, "%s - open failed %i\n", __func__, result);
    296		if (result >= 0)
    297			result = -EIO;
    298		kfree(data);
    299		return result;
    300	}
    301
    302	spin_lock_irqsave(&priv->status_lock, flags);
    303	priv->shadowLSR = data[0];
    304	priv->shadowMSR = data[1];
    305	spin_unlock_irqrestore(&priv->status_lock, flags);
    306
    307	kfree(data);
    308
    309/* set to 9600 */
    310	result = ssu100_control_msg(dev, QT_GET_SET_UART, 0x30, 0x0300);
    311	if (result < 0)
    312		dev_dbg(&port->dev, "%s - set uart failed\n", __func__);
    313
    314	if (tty)
    315		ssu100_set_termios(tty, port, &tty->termios);
    316
    317	return usb_serial_generic_open(tty, port);
    318}
    319
    320static int ssu100_attach(struct usb_serial *serial)
    321{
    322	return ssu100_initdevice(serial->dev);
    323}
    324
    325static int ssu100_port_probe(struct usb_serial_port *port)
    326{
    327	struct ssu100_port_private *priv;
    328
    329	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
    330	if (!priv)
    331		return -ENOMEM;
    332
    333	spin_lock_init(&priv->status_lock);
    334
    335	usb_set_serial_port_data(port, priv);
    336
    337	return 0;
    338}
    339
    340static void ssu100_port_remove(struct usb_serial_port *port)
    341{
    342	struct ssu100_port_private *priv;
    343
    344	priv = usb_get_serial_port_data(port);
    345	kfree(priv);
    346}
    347
    348static int ssu100_tiocmget(struct tty_struct *tty)
    349{
    350	struct usb_serial_port *port = tty->driver_data;
    351	struct usb_device *dev = port->serial->dev;
    352	u8 *d;
    353	int r;
    354
    355	d = kzalloc(2, GFP_KERNEL);
    356	if (!d)
    357		return -ENOMEM;
    358
    359	r = ssu100_getregister(dev, 0, UART_MCR, d);
    360	if (r < 0)
    361		goto mget_out;
    362
    363	r = ssu100_getregister(dev, 0, UART_MSR, d+1);
    364	if (r < 0)
    365		goto mget_out;
    366
    367	r = (d[0] & UART_MCR_DTR ? TIOCM_DTR : 0) |
    368		(d[0] & UART_MCR_RTS ? TIOCM_RTS : 0) |
    369		(d[1] & UART_MSR_CTS ? TIOCM_CTS : 0) |
    370		(d[1] & UART_MSR_DCD ? TIOCM_CAR : 0) |
    371		(d[1] & UART_MSR_RI ? TIOCM_RI : 0) |
    372		(d[1] & UART_MSR_DSR ? TIOCM_DSR : 0);
    373
    374mget_out:
    375	kfree(d);
    376	return r;
    377}
    378
    379static int ssu100_tiocmset(struct tty_struct *tty,
    380			   unsigned int set, unsigned int clear)
    381{
    382	struct usb_serial_port *port = tty->driver_data;
    383	struct usb_device *dev = port->serial->dev;
    384
    385	return update_mctrl(dev, set, clear);
    386}
    387
    388static void ssu100_dtr_rts(struct usb_serial_port *port, int on)
    389{
    390	struct usb_device *dev = port->serial->dev;
    391
    392	/* Disable flow control */
    393	if (!on) {
    394		if (ssu100_setregister(dev, 0, UART_MCR, 0) < 0)
    395			dev_err(&port->dev, "error from flowcontrol urb\n");
    396	}
    397	/* drop RTS and DTR */
    398	if (on)
    399		set_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
    400	else
    401		clear_mctrl(dev, TIOCM_DTR | TIOCM_RTS);
    402}
    403
    404static void ssu100_update_msr(struct usb_serial_port *port, u8 msr)
    405{
    406	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
    407	unsigned long flags;
    408
    409	spin_lock_irqsave(&priv->status_lock, flags);
    410	priv->shadowMSR = msr;
    411	spin_unlock_irqrestore(&priv->status_lock, flags);
    412
    413	if (msr & UART_MSR_ANY_DELTA) {
    414		/* update input line counters */
    415		if (msr & UART_MSR_DCTS)
    416			port->icount.cts++;
    417		if (msr & UART_MSR_DDSR)
    418			port->icount.dsr++;
    419		if (msr & UART_MSR_DDCD)
    420			port->icount.dcd++;
    421		if (msr & UART_MSR_TERI)
    422			port->icount.rng++;
    423		wake_up_interruptible(&port->port.delta_msr_wait);
    424	}
    425}
    426
    427static void ssu100_update_lsr(struct usb_serial_port *port, u8 lsr,
    428			      char *tty_flag)
    429{
    430	struct ssu100_port_private *priv = usb_get_serial_port_data(port);
    431	unsigned long flags;
    432
    433	spin_lock_irqsave(&priv->status_lock, flags);
    434	priv->shadowLSR = lsr;
    435	spin_unlock_irqrestore(&priv->status_lock, flags);
    436
    437	*tty_flag = TTY_NORMAL;
    438	if (lsr & UART_LSR_BRK_ERROR_BITS) {
    439		/* we always want to update icount, but we only want to
    440		 * update tty_flag for one case */
    441		if (lsr & UART_LSR_BI) {
    442			port->icount.brk++;
    443			*tty_flag = TTY_BREAK;
    444			usb_serial_handle_break(port);
    445		}
    446		if (lsr & UART_LSR_PE) {
    447			port->icount.parity++;
    448			if (*tty_flag == TTY_NORMAL)
    449				*tty_flag = TTY_PARITY;
    450		}
    451		if (lsr & UART_LSR_FE) {
    452			port->icount.frame++;
    453			if (*tty_flag == TTY_NORMAL)
    454				*tty_flag = TTY_FRAME;
    455		}
    456		if (lsr & UART_LSR_OE) {
    457			port->icount.overrun++;
    458			tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
    459		}
    460	}
    461
    462}
    463
    464static void ssu100_process_read_urb(struct urb *urb)
    465{
    466	struct usb_serial_port *port = urb->context;
    467	char *packet = urb->transfer_buffer;
    468	char flag = TTY_NORMAL;
    469	u32 len = urb->actual_length;
    470	int i;
    471	char *ch;
    472
    473	if ((len >= 4) &&
    474	    (packet[0] == 0x1b) && (packet[1] == 0x1b) &&
    475	    ((packet[2] == 0x00) || (packet[2] == 0x01))) {
    476		if (packet[2] == 0x00)
    477			ssu100_update_lsr(port, packet[3], &flag);
    478		if (packet[2] == 0x01)
    479			ssu100_update_msr(port, packet[3]);
    480
    481		len -= 4;
    482		ch = packet + 4;
    483	} else
    484		ch = packet;
    485
    486	if (!len)
    487		return;	/* status only */
    488
    489	if (port->sysrq) {
    490		for (i = 0; i < len; i++, ch++) {
    491			if (!usb_serial_handle_sysrq_char(port, *ch))
    492				tty_insert_flip_char(&port->port, *ch, flag);
    493		}
    494	} else {
    495		tty_insert_flip_string_fixed_flag(&port->port, ch, flag, len);
    496	}
    497
    498	tty_flip_buffer_push(&port->port);
    499}
    500
    501static struct usb_serial_driver ssu100_device = {
    502	.driver = {
    503		.owner = THIS_MODULE,
    504		.name = "ssu100",
    505	},
    506	.description	     = DRIVER_DESC,
    507	.id_table	     = id_table,
    508	.num_ports	     = 1,
    509	.open		     = ssu100_open,
    510	.attach              = ssu100_attach,
    511	.port_probe          = ssu100_port_probe,
    512	.port_remove         = ssu100_port_remove,
    513	.dtr_rts             = ssu100_dtr_rts,
    514	.process_read_urb    = ssu100_process_read_urb,
    515	.tiocmget            = ssu100_tiocmget,
    516	.tiocmset            = ssu100_tiocmset,
    517	.tiocmiwait          = usb_serial_generic_tiocmiwait,
    518	.get_icount	     = usb_serial_generic_get_icount,
    519	.set_termios         = ssu100_set_termios,
    520};
    521
    522static struct usb_serial_driver * const serial_drivers[] = {
    523	&ssu100_device, NULL
    524};
    525
    526module_usb_serial_driver(serial_drivers, id_table);
    527
    528MODULE_DESCRIPTION(DRIVER_DESC);
    529MODULE_LICENSE("GPL v2");