forked from ~ljy/RK356X_SDK_RELEASE
blame | history | patch | commit | commitdiff
hc
2023-12-09 95099d4622f8cb224d94e314c7a8e0df60b13f87 
 kernel/drivers/usb/serial/cp210x.c
....@@ -50,6 +50,9 @@
5050 static int cp210x_port_probe(struct usb_serial_port *);
5151 static int cp210x_port_remove(struct usb_serial_port *);
5252 static void cp210x_dtr_rts(struct usb_serial_port *p, int on);
53
+static void cp210x_process_read_urb(struct urb *urb);
54
+static void cp210x_enable_event_mode(struct usb_serial_port *port);
55
+static void cp210x_disable_event_mode(struct usb_serial_port *port);
5356 
5457 static const struct usb_device_id id_table[] = {
5558 	{ USB_DEVICE(0x0404, 0x034C) },	/* NCR Retail IO Box */
....@@ -131,6 +134,7 @@
131134 	{ USB_DEVICE(0x10C4, 0x83AA) }, /* Mark-10 Digital Force Gauge */
132135 	{ USB_DEVICE(0x10C4, 0x83D8) }, /* DekTec DTA Plus VHF/UHF Booster/Attenuator */
133136 	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
137
+	{ USB_DEVICE(0x10C4, 0x8414) }, /* Decagon USB Cable Adapter */
134138 	{ USB_DEVICE(0x10C4, 0x8418) }, /* IRZ Automation Teleport SG-10 GSM/GPRS Modem */
135139 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
136140 	{ USB_DEVICE(0x10C4, 0x8470) }, /* Juniper Networks BX Series System Console */
....@@ -195,6 +199,10 @@
195199 	{ USB_DEVICE(0x16DC, 0x0015) }, /* W-IE-NE-R Plein & Baus GmbH CML Control, Monitoring and Data Logger */
196200 	{ USB_DEVICE(0x17A8, 0x0001) }, /* Kamstrup Optical Eye/3-wire */
197201 	{ USB_DEVICE(0x17A8, 0x0005) }, /* Kamstrup M-Bus Master MultiPort 250D */
202
+	{ USB_DEVICE(0x17A8, 0x0011) }, /* Kamstrup 444 MHz RF sniffer */
203
+	{ USB_DEVICE(0x17A8, 0x0013) }, /* Kamstrup 870 MHz RF sniffer */
204
+	{ USB_DEVICE(0x17A8, 0x0101) }, /* Kamstrup 868 MHz wM-Bus C-Mode Meter Reader (Int Ant) */
205
+	{ USB_DEVICE(0x17A8, 0x0102) }, /* Kamstrup 868 MHz wM-Bus C-Mode Meter Reader (Ext Ant) */
198206 	{ USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
199207 	{ USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
200208 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
....@@ -257,13 +265,27 @@
257265 	u8			gpio_input;
258266 #endif
259267 	u8			partnum;
268
+	speed_t			min_speed;
260269 	speed_t			max_speed;
261270 	bool			use_actual_rate;
271
+	bool			no_event_mode;
272
+};
273
+
274
+enum cp210x_event_state {
275
+	ES_DATA,
276
+	ES_ESCAPE,
277
+	ES_LSR,
278
+	ES_LSR_DATA_0,
279
+	ES_LSR_DATA_1,
280
+	ES_MSR
262281 };
263282 
264283 struct cp210x_port_private {
265
-	__u8			bInterfaceNumber;
284
+	u8			bInterfaceNumber;
266285 	bool			has_swapped_line_ctl;
286
+	bool			event_mode;
287
+	enum cp210x_event_state event_state;
288
+	u8 lsr;
267289 };
268290 
269291 static struct usb_serial_driver cp210x_device = {
....@@ -284,12 +306,14 @@
284306 	.unthrottle		= usb_serial_generic_unthrottle,
285307 	.tiocmget		= cp210x_tiocmget,
286308 	.tiocmset		= cp210x_tiocmset,
309
+	.get_icount		= usb_serial_generic_get_icount,
287310 	.attach			= cp210x_attach,
288311 	.disconnect		= cp210x_disconnect,
289312 	.release		= cp210x_release,
290313 	.port_probe		= cp210x_port_probe,
291314 	.port_remove		= cp210x_port_remove,
292
-	.dtr_rts		= cp210x_dtr_rts
315
+	.dtr_rts		= cp210x_dtr_rts,
316
+	.process_read_urb	= cp210x_process_read_urb,
293317 };
294318 
295319 static struct usb_serial_driver * const serial_drivers[] = {
....@@ -411,13 +435,22 @@
411435  */
412436 #define PURGE_ALL		0x000f
413437 
438
+/* CP210X_EMBED_EVENTS */
439
+#define CP210X_ESCCHAR		0xec
440
+
441
+#define CP210X_LSR_OVERRUN	BIT(1)
442
+#define CP210X_LSR_PARITY	BIT(2)
443
+#define CP210X_LSR_FRAME	BIT(3)
444
+#define CP210X_LSR_BREAK	BIT(4)
445
+
446
+
414447 /* CP210X_GET_FLOW/CP210X_SET_FLOW read/write these 0x10 bytes */
415448 struct cp210x_flow_ctl {
416449 	__le32	ulControlHandshake;
417450 	__le32	ulFlowReplace;
418451 	__le32	ulXonLimit;
419452 	__le32	ulXoffLimit;
420
-} __packed;
453
+};
421454 
422455 /* cp210x_flow_ctl::ulControlHandshake */
423456 #define CP210X_SERIAL_DTR_MASK		GENMASK(1, 0)
....@@ -451,16 +484,16 @@
451484 struct cp210x_pin_mode {
452485 	u8	eci;
453486 	u8	sci;
454
-} __packed;
487
+};
455488 
456489 #define CP210X_PIN_MODE_MODEM		0
457490 #define CP210X_PIN_MODE_GPIO		BIT(0)
458491 
459492 /*
460
- * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 0xf bytes.
461
- * Structure needs padding due to unused/unspecified bytes.
493
+ * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 0xf bytes
494
+ * on a CP2105 chip. Structure needs padding due to unused/unspecified bytes.
462495  */
463
-struct cp210x_config {
496
+struct cp210x_dual_port_config {
464497 	__le16	gpio_mode;
465498 	u8	__pad0[2];
466499 	__le16	reset_state;
....@@ -471,6 +504,19 @@
471504 	u8	device_cfg;
472505 } __packed;
473506 
507
+/*
508
+ * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 0xd bytes
509
+ * on a CP2104 chip. Structure needs padding due to unused/unspecified bytes.
510
+ */
511
+struct cp210x_single_port_config {
512
+	__le16	gpio_mode;
513
+	u8	__pad0[2];
514
+	__le16	reset_state;
515
+	u8	__pad1[4];
516
+	__le16	suspend_state;
517
+	u8	device_cfg;
518
+} __packed;
519
+
474520 /* GPIO modes */
475521 #define CP210X_SCI_GPIO_MODE_OFFSET	9
476522 #define CP210X_SCI_GPIO_MODE_MASK	GENMASK(11, 9)
....@@ -478,10 +524,18 @@
478524 #define CP210X_ECI_GPIO_MODE_OFFSET	2
479525 #define CP210X_ECI_GPIO_MODE_MASK	GENMASK(3, 2)
480526 
527
+#define CP210X_GPIO_MODE_OFFSET		8
528
+#define CP210X_GPIO_MODE_MASK		GENMASK(11, 8)
529
+
481530 /* CP2105 port configuration values */
482531 #define CP2105_GPIO0_TXLED_MODE		BIT(0)
483532 #define CP2105_GPIO1_RXLED_MODE		BIT(1)
484533 #define CP2105_GPIO1_RS485_MODE		BIT(2)
534
+
535
+/* CP2104 port configuration values */
536
+#define CP2104_GPIO0_TXLED_MODE		BIT(0)
537
+#define CP2104_GPIO1_RXLED_MODE		BIT(1)
538
+#define CP2104_GPIO2_RS485_MODE		BIT(2)
485539 
486540 /* CP2102N configuration array indices */
487541 #define CP210X_2NCONFIG_CONFIG_VERSION_IDX	2
....@@ -499,7 +553,7 @@
499553 struct cp210x_gpio_write {
500554 	u8	mask;
501555 	u8	state;
502
-} __packed;
556
+};
503557 
504558 /*
505559  * Helper to get interface number when we only have struct usb_serial.
....@@ -802,6 +856,7 @@
802856 
803857 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
804858 {
859
+	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
805860 	int result;
806861 
807862 	result = cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_ENABLE);
....@@ -813,21 +868,144 @@
813868 	/* Configure the termios structure */
814869 	cp210x_get_termios(tty, port);
815870 
816
-	/* The baud rate must be initialised on cp2104 */
817
-	if (tty)
871
+	if (tty) {
872
+		/* The baud rate must be initialised on cp2104 */
818873 		cp210x_change_speed(tty, port, NULL);
819874 
820
-	return usb_serial_generic_open(tty, port);
875
+		if (I_INPCK(tty))
876
+			cp210x_enable_event_mode(port);
877
+	}
878
+
879
+	result = usb_serial_generic_open(tty, port);
880
+	if (result)
881
+		goto err_disable;
882
+
883
+	return 0;
884
+
885
+err_disable:
886
+	cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_DISABLE);
887
+	port_priv->event_mode = false;
888
+
889
+	return result;
821890 }
822891 
823892 static void cp210x_close(struct usb_serial_port *port)
824893 {
894
+	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
895
+
825896 	usb_serial_generic_close(port);
826897 
827898 	/* Clear both queues; cp2108 needs this to avoid an occasional hang */
828899 	cp210x_write_u16_reg(port, CP210X_PURGE, PURGE_ALL);
829900 
830901 	cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_DISABLE);
902
+
903
+	/* Disabling the interface disables event-insertion mode. */
904
+	port_priv->event_mode = false;
905
+}
906
+
907
+static void cp210x_process_lsr(struct usb_serial_port *port, unsigned char lsr, char *flag)
908
+{
909
+	if (lsr & CP210X_LSR_BREAK) {
910
+		port->icount.brk++;
911
+		*flag = TTY_BREAK;
912
+	} else if (lsr & CP210X_LSR_PARITY) {
913
+		port->icount.parity++;
914
+		*flag = TTY_PARITY;
915
+	} else if (lsr & CP210X_LSR_FRAME) {
916
+		port->icount.frame++;
917
+		*flag = TTY_FRAME;
918
+	}
919
+
920
+	if (lsr & CP210X_LSR_OVERRUN) {
921
+		port->icount.overrun++;
922
+		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
923
+	}
924
+}
925
+
926
+static bool cp210x_process_char(struct usb_serial_port *port, unsigned char *ch, char *flag)
927
+{
928
+	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
929
+
930
+	switch (port_priv->event_state) {
931
+	case ES_DATA:
932
+		if (*ch == CP210X_ESCCHAR) {
933
+			port_priv->event_state = ES_ESCAPE;
934
+			break;
935
+		}
936
+		return false;
937
+	case ES_ESCAPE:
938
+		switch (*ch) {
939
+		case 0:
940
+			dev_dbg(&port->dev, "%s - escape char\n", __func__);
941
+			*ch = CP210X_ESCCHAR;
942
+			port_priv->event_state = ES_DATA;
943
+			return false;
944
+		case 1:
945
+			port_priv->event_state = ES_LSR_DATA_0;
946
+			break;
947
+		case 2:
948
+			port_priv->event_state = ES_LSR;
949
+			break;
950
+		case 3:
951
+			port_priv->event_state = ES_MSR;
952
+			break;
953
+		default:
954
+			dev_err(&port->dev, "malformed event 0x%02x\n", *ch);
955
+			port_priv->event_state = ES_DATA;
956
+			break;
957
+		}
958
+		break;
959
+	case ES_LSR_DATA_0:
960
+		port_priv->lsr = *ch;
961
+		port_priv->event_state = ES_LSR_DATA_1;
962
+		break;
963
+	case ES_LSR_DATA_1:
964
+		dev_dbg(&port->dev, "%s - lsr = 0x%02x, data = 0x%02x\n",
965
+				__func__, port_priv->lsr, *ch);
966
+		cp210x_process_lsr(port, port_priv->lsr, flag);
967
+		port_priv->event_state = ES_DATA;
968
+		return false;
969
+	case ES_LSR:
970
+		dev_dbg(&port->dev, "%s - lsr = 0x%02x\n", __func__, *ch);
971
+		port_priv->lsr = *ch;
972
+		cp210x_process_lsr(port, port_priv->lsr, flag);
973
+		port_priv->event_state = ES_DATA;
974
+		break;
975
+	case ES_MSR:
976
+		dev_dbg(&port->dev, "%s - msr = 0x%02x\n", __func__, *ch);
977
+		/* unimplemented */
978
+		port_priv->event_state = ES_DATA;
979
+		break;
980
+	}
981
+
982
+	return true;
983
+}
984
+
985
+static void cp210x_process_read_urb(struct urb *urb)
986
+{
987
+	struct usb_serial_port *port = urb->context;
988
+	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
989
+	unsigned char *ch = urb->transfer_buffer;
990
+	char flag;
991
+	int i;
992
+
993
+	if (!urb->actual_length)
994
+		return;
995
+
996
+	if (port_priv->event_mode) {
997
+		for (i = 0; i < urb->actual_length; i++, ch++) {
998
+			flag = TTY_NORMAL;
999
+
1000
+			if (cp210x_process_char(port, ch, &flag))
1001
+				continue;
1002
+
1003
+			tty_insert_flip_char(&port->port, *ch, flag);
1004
+		}
1005
+	} else {
1006
+		tty_insert_flip_string(&port->port, ch, urb->actual_length);
1007
+	}
1008
+	tty_flip_buffer_push(&port->port);
8311009 }
8321010 
8331011 /*
....@@ -1088,13 +1266,10 @@
10881266 	return cp210x_an205_table1[i].rate;
10891267 }
10901268 
1091
-static speed_t cp210x_get_actual_rate(struct usb_serial *serial, speed_t baud)
1269
+static speed_t cp210x_get_actual_rate(speed_t baud)
10921270 {
1093
-	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
10941271 	unsigned int prescale = 1;
10951272 	unsigned int div;
1096
-
1097
-	baud = clamp(baud, 300u, priv->max_speed);
10981273 
10991274 	if (baud <= 365)
11001275 		prescale = 4;
....@@ -1138,20 +1313,18 @@
11381313 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
11391314 	u32 baud;
11401315 
1141
-	baud = tty->termios.c_ospeed;
1142
-
11431316 	/*
11441317 	 * This maps the requested rate to the actual rate, a valid rate on
11451318 	 * cp2102 or cp2103, or to an arbitrary rate in [1M, max_speed].
11461319 	 *
11471320 	 * NOTE: B0 is not implemented.
11481321 	 */
1322
+	baud = clamp(tty->termios.c_ospeed, priv->min_speed, priv->max_speed);
1323
+
11491324 	if (priv->use_actual_rate)
1150
-		baud = cp210x_get_actual_rate(serial, baud);
1325
+		baud = cp210x_get_actual_rate(baud);
11511326 	else if (baud < 1000000)
11521327 		baud = cp210x_get_an205_rate(baud);
1153
-	else if (baud > priv->max_speed)
1154
-		baud = priv->max_speed;
11551328 
11561329 	dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
11571330 	if (cp210x_write_u32_reg(port, CP210X_SET_BAUDRATE, baud)) {
....@@ -1163,6 +1336,45 @@
11631336 	}
11641337 
11651338 	tty_encode_baud_rate(tty, baud, baud);
1339
+}
1340
+
1341
+static void cp210x_enable_event_mode(struct usb_serial_port *port)
1342
+{
1343
+	struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
1344
+	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
1345
+	int ret;
1346
+
1347
+	if (port_priv->event_mode)
1348
+		return;
1349
+
1350
+	if (priv->no_event_mode)
1351
+		return;
1352
+
1353
+	port_priv->event_state = ES_DATA;
1354
+	port_priv->event_mode = true;
1355
+
1356
+	ret = cp210x_write_u16_reg(port, CP210X_EMBED_EVENTS, CP210X_ESCCHAR);
1357
+	if (ret) {
1358
+		dev_err(&port->dev, "failed to enable events: %d\n", ret);
1359
+		port_priv->event_mode = false;
1360
+	}
1361
+}
1362
+
1363
+static void cp210x_disable_event_mode(struct usb_serial_port *port)
1364
+{
1365
+	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
1366
+	int ret;
1367
+
1368
+	if (!port_priv->event_mode)
1369
+		return;
1370
+
1371
+	ret = cp210x_write_u16_reg(port, CP210X_EMBED_EVENTS, 0);
1372
+	if (ret) {
1373
+		dev_err(&port->dev, "failed to disable events: %d\n", ret);
1374
+		return;
1375
+	}
1376
+
1377
+	port_priv->event_mode = false;
11661378 }
11671379 
11681380 static void cp210x_set_termios(struct tty_struct *tty,
....@@ -1287,6 +1499,14 @@
12871499 				sizeof(flow_ctl));
12881500 	}
12891501 
1502
+	/*
1503
+	 * Enable event-insertion mode only if input parity checking is
1504
+	 * enabled for now.
1505
+	 */
1506
+	if (I_INPCK(tty))
1507
+		cp210x_enable_event_mode(port);
1508
+	else
1509
+		cp210x_disable_event_mode(port);
12901510 }
12911511 
12921512 static int cp210x_tiocmset(struct tty_struct *tty,
....@@ -1518,7 +1738,7 @@
15181738 {
15191739 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
15201740 	struct cp210x_pin_mode mode;
1521
-	struct cp210x_config config;
1741
+	struct cp210x_dual_port_config config;
15221742 	u8 intf_num = cp210x_interface_num(serial);
15231743 	u8 iface_config;
15241744 	int result;
....@@ -1579,6 +1799,56 @@
15791799 	return 0;
15801800 }
15811801 
1802
+static int cp2104_gpioconf_init(struct usb_serial *serial)
1803
+{
1804
+	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1805
+	struct cp210x_single_port_config config;
1806
+	u8 iface_config;
1807
+	u8 gpio_latch;
1808
+	int result;
1809
+	u8 i;
1810
+
1811
+	result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
1812
+					  CP210X_GET_PORTCONFIG, &config,
1813
+					  sizeof(config));
1814
+	if (result < 0)
1815
+		return result;
1816
+
1817
+	priv->gc.ngpio = 4;
1818
+
1819
+	iface_config = config.device_cfg;
1820
+	priv->gpio_pushpull = (u8)((le16_to_cpu(config.gpio_mode) &
1821
+					CP210X_GPIO_MODE_MASK) >>
1822
+					CP210X_GPIO_MODE_OFFSET);
1823
+	gpio_latch = (u8)((le16_to_cpu(config.reset_state) &
1824
+					CP210X_GPIO_MODE_MASK) >>
1825
+					CP210X_GPIO_MODE_OFFSET);
1826
+
1827
+	/* mark all pins which are not in GPIO mode */
1828
+	if (iface_config & CP2104_GPIO0_TXLED_MODE)	/* GPIO 0 */
1829
+		priv->gpio_altfunc |= BIT(0);
1830
+	if (iface_config & CP2104_GPIO1_RXLED_MODE)	/* GPIO 1 */
1831
+		priv->gpio_altfunc |= BIT(1);
1832
+	if (iface_config & CP2104_GPIO2_RS485_MODE)	/* GPIO 2 */
1833
+		priv->gpio_altfunc |= BIT(2);
1834
+
1835
+	/*
1836
+	 * Like CP2102N, CP2104 has also no strict input and output pin
1837
+	 * modes.
1838
+	 * Do the same input mode emulation as CP2102N.
1839
+	 */
1840
+	for (i = 0; i < priv->gc.ngpio; ++i) {
1841
+		/*
1842
+		 * Set direction to "input" iff pin is open-drain and reset
1843
+		 * value is 1.
1844
+		 */
1845
+		if (!(priv->gpio_pushpull & BIT(i)) && (gpio_latch & BIT(i)))
1846
+			priv->gpio_input |= BIT(i);
1847
+	}
1848
+
1849
+	return 0;
1850
+}
1851
+
15821852 static int cp2102n_gpioconf_init(struct usb_serial *serial)
15831853 {
15841854 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
....@@ -1624,12 +1894,6 @@
16241894 	if (config_version != 0x01)
16251895 		return -ENOTSUPP;
16261896 
1627
-	/*
1628
-	 * We only support 4 GPIOs even on the QFN28 package, because
1629
-	 * config locations of GPIOs 4-6 determined using reverse
1630
-	 * engineering revealed conflicting offsets with other
1631
-	 * documented functions. So we'll just play it safe for now.
1632
-	 */
16331897 	priv->gc.ngpio = 4;
16341898 
16351899 	/*
....@@ -1654,6 +1918,19 @@
16541918 			priv->gpio_altfunc |= BIT(3);
16551919 	} else {
16561920 		priv->gpio_altfunc = (gpio_ctrl >> 2) & 0x0f;
1921
+	}
1922
+
1923
+	if (priv->partnum == CP210X_PARTNUM_CP2102N_QFN28) {
1924
+		/*
1925
+		 * For the QFN28 package, GPIO4-6 are controlled by
1926
+		 * the low three bits of the mode/latch fields.
1927
+		 * Contrary to the document linked above, the bits for
1928
+		 * the SUSPEND pins are elsewhere.  No alternate
1929
+		 * function is available for these pins.
1930
+		 */
1931
+		priv->gc.ngpio = 7;
1932
+		gpio_latch |= (gpio_rst_latch & 7) << 4;
1933
+		priv->gpio_pushpull |= (gpio_pushpull & 7) << 4;
16571934 	}
16581935 
16591936 	/*
....@@ -1682,6 +1959,9 @@
16821959 	int result;
16831960 
16841961 	switch (priv->partnum) {
1962
+	case CP210X_PARTNUM_CP2104:
1963
+		result = cp2104_gpioconf_init(serial);
1964
+		break;
16851965 	case CP210X_PARTNUM_CP2105:
16861966 		result = cp2105_gpioconf_init(serial);
16871967 		break;
....@@ -1778,6 +2058,7 @@
17782058 {
17792059 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
17802060 	bool use_actual_rate = false;
2061
+	speed_t min = 300;
17812062 	speed_t max;
17822063 
17832064 	switch (priv->partnum) {
....@@ -1800,6 +2081,7 @@
18002081 			use_actual_rate = true;
18012082 			max = 2000000;	/* ECI */
18022083 		} else {
2084
+			min = 2400;
18032085 			max = 921600;	/* SCI */
18042086 		}
18052087 		break;
....@@ -1814,8 +2096,49 @@
18142096 		break;
18152097 	}
18162098 
2099
+	priv->min_speed = min;
18172100 	priv->max_speed = max;
18182101 	priv->use_actual_rate = use_actual_rate;
2102
+}
2103
+
2104
+static void cp2102_determine_quirks(struct usb_serial *serial)
2105
+{
2106
+	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
2107
+	u8 *buf;
2108
+	int ret;
2109
+
2110
+	buf = kmalloc(2, GFP_KERNEL);
2111
+	if (!buf)
2112
+		return;
2113
+	/*
2114
+	 * Some (possibly counterfeit) CP2102 do not support event-insertion
2115
+	 * mode and respond differently to malformed vendor requests.
2116
+	 * Specifically, they return one instead of two bytes when sent a
2117
+	 * two-byte part-number request.
2118
+	 */
2119
+	ret = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
2120
+			CP210X_VENDOR_SPECIFIC, REQTYPE_DEVICE_TO_HOST,
2121
+			CP210X_GET_PARTNUM, 0, buf, 2, USB_CTRL_GET_TIMEOUT);
2122
+	if (ret == 1) {
2123
+		dev_dbg(&serial->interface->dev,
2124
+				"device does not support event-insertion mode\n");
2125
+		priv->no_event_mode = true;
2126
+	}
2127
+
2128
+	kfree(buf);
2129
+}
2130
+
2131
+static void cp210x_determine_quirks(struct usb_serial *serial)
2132
+{
2133
+	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
2134
+
2135
+	switch (priv->partnum) {
2136
+	case CP210X_PARTNUM_CP2102:
2137
+		cp2102_determine_quirks(serial);
2138
+		break;
2139
+	default:
2140
+		break;
2141
+	}
18192142 }
18202143 
18212144 static int cp210x_attach(struct usb_serial *serial)
....@@ -1838,6 +2161,7 @@
18382161 
18392162 	usb_set_serial_data(serial, priv);
18402163 
2164
+	cp210x_determine_quirks(serial);
18412165 	cp210x_init_max_speed(serial);
18422166 
18432167 	result = cp210x_gpio_init(serial);