xref: /linux/drivers/usb/serial/cp210x.c (revision 83b67041f3eaf33f98a075249aa7f4c7617c2f85)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Silicon Laboratories CP210x USB to RS232 serial adaptor driver
4  *
5  * Copyright (C) 2005 Craig Shelley (craig@microtron.org.uk)
6  * Copyright (C) 2010-2021 Johan Hovold (johan@kernel.org)
7  *
8  * Support to set flow control line levels using TIOCMGET and TIOCMSET
9  * thanks to Karl Hiramoto karl@hiramoto.org. RTSCTS hardware flow
10  * control thanks to Munir Nassar nassarmu@real-time.com
11  *
12  */
13 
14 #include <linux/kernel.h>
15 #include <linux/errno.h>
16 #include <linux/slab.h>
17 #include <linux/tty.h>
18 #include <linux/tty_flip.h>
19 #include <linux/module.h>
20 #include <linux/usb.h>
21 #include <linux/usb/serial.h>
22 #include <linux/gpio/driver.h>
23 #include <linux/bitops.h>
24 #include <linux/mutex.h>
25 
26 #define DRIVER_DESC "Silicon Labs CP210x RS232 serial adaptor driver"
27 
28 /*
29  * Function Prototypes
30  */
31 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *);
32 static void cp210x_close(struct usb_serial_port *);
33 static void cp210x_change_speed(struct tty_struct *, struct usb_serial_port *,
34 							struct ktermios *);
35 static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
36 							struct ktermios*);
37 static bool cp210x_tx_empty(struct usb_serial_port *port);
38 static int cp210x_tiocmget(struct tty_struct *);
39 static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
40 static int cp210x_tiocmset_port(struct usb_serial_port *port,
41 		unsigned int, unsigned int);
42 static void cp210x_break_ctl(struct tty_struct *, int);
43 static int cp210x_attach(struct usb_serial *);
44 static void cp210x_disconnect(struct usb_serial *);
45 static void cp210x_release(struct usb_serial *);
46 static int cp210x_port_probe(struct usb_serial_port *);
47 static void cp210x_port_remove(struct usb_serial_port *);
48 static void cp210x_dtr_rts(struct usb_serial_port *port, int on);
49 static void cp210x_process_read_urb(struct urb *urb);
50 static void cp210x_enable_event_mode(struct usb_serial_port *port);
51 static void cp210x_disable_event_mode(struct usb_serial_port *port);
52 
53 static const struct usb_device_id id_table[] = {
54 	{ USB_DEVICE(0x045B, 0x0053) }, /* Renesas RX610 RX-Stick */
55 	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
56 	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
57 	{ USB_DEVICE(0x0489, 0xE003) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
58 	{ USB_DEVICE(0x0745, 0x1000) }, /* CipherLab USB CCD Barcode Scanner 1000 */
59 	{ USB_DEVICE(0x0846, 0x1100) }, /* NetGear Managed Switch M4100 series, M5300 series, M7100 series */
60 	{ USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
61 	{ USB_DEVICE(0x08FD, 0x000A) }, /* Digianswer A/S , ZigBee/802.15.4 MAC Device */
62 	{ USB_DEVICE(0x0908, 0x01FF) }, /* Siemens RUGGEDCOM USB Serial Console */
63 	{ USB_DEVICE(0x0988, 0x0578) }, /* Teraoka AD2000 */
64 	{ USB_DEVICE(0x0B00, 0x3070) }, /* Ingenico 3070 */
65 	{ USB_DEVICE(0x0BED, 0x1100) }, /* MEI (TM) Cashflow-SC Bill/Voucher Acceptor */
66 	{ USB_DEVICE(0x0BED, 0x1101) }, /* MEI series 2000 Combo Acceptor */
67 	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
68 	{ USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
69 	{ USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
70 	{ USB_DEVICE(0x0FDE, 0xCA05) }, /* OWL Wireless Electricity Monitor CM-160 */
71 	{ USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
72 	{ USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
73 	{ USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
74 	{ USB_DEVICE(0x10C4, 0x0F91) }, /* Vstabi */
75 	{ USB_DEVICE(0x10C4, 0x1101) }, /* Arkham Technology DS101 Bus Monitor */
76 	{ USB_DEVICE(0x10C4, 0x1601) }, /* Arkham Technology DS101 Adapter */
77 	{ USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
78 	{ USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
79 	{ USB_DEVICE(0x10C4, 0x8044) }, /* Cygnal Debug Adapter */
80 	{ USB_DEVICE(0x10C4, 0x804E) }, /* Software Bisque Paramount ME build-in converter */
81 	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
82 	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
83 	{ USB_DEVICE(0x10C4, 0x8056) }, /* Lorenz Messtechnik devices */
84 	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
85 	{ USB_DEVICE(0x10C4, 0x806F) }, /* IMS USB to RS422 Converter Cable */
86 	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
87 	{ USB_DEVICE(0x10C4, 0x80C4) }, /* Cygnal Integrated Products, Inc., Optris infrared thermometer */
88 	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
89 	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
90 	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
91 	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
92 	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
93 	{ USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
94 	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
95 	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
96 	{ USB_DEVICE(0x2405, 0x0003) }, /* West Mountain Radio RIGblaster Advantage */
97 	{ USB_DEVICE(0x10C4, 0x8156) }, /* B&G H3000 link cable */
98 	{ USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
99 	{ USB_DEVICE(0x10C4, 0x815F) }, /* Timewave HamLinkUSB */
100 	{ USB_DEVICE(0x10C4, 0x817C) }, /* CESINEL MEDCAL N Power Quality Monitor */
101 	{ USB_DEVICE(0x10C4, 0x817D) }, /* CESINEL MEDCAL NT Power Quality Monitor */
102 	{ USB_DEVICE(0x10C4, 0x817E) }, /* CESINEL MEDCAL S Power Quality Monitor */
103 	{ USB_DEVICE(0x10C4, 0x818B) }, /* AVIT Research USB to TTL */
104 	{ USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
105 	{ USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
106 	{ USB_DEVICE(0x10C4, 0x81A9) }, /* Multiplex RC Interface */
107 	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
108 	{ USB_DEVICE(0x10C4, 0x81AD) }, /* INSYS USB Modem */
109 	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
110 	{ USB_DEVICE(0x10C4, 0x81D7) }, /* IAI Corp. RCB-CV-USB USB to RS485 Adaptor */
111 	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
112 	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
113 	{ USB_DEVICE(0x10C4, 0x81E8) }, /* Zephyr Bioharness */
114 	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
115 	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
116 	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
117 	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demonstration module */
118 	{ USB_DEVICE(0x10C4, 0x8281) }, /* Nanotec Plug & Drive */
119 	{ USB_DEVICE(0x10C4, 0x8293) }, /* Telegesis ETRX2USB */
120 	{ USB_DEVICE(0x10C4, 0x82EF) }, /* CESINEL FALCO 6105 AC Power Supply */
121 	{ USB_DEVICE(0x10C4, 0x82F1) }, /* CESINEL MEDCAL EFD Earth Fault Detector */
122 	{ USB_DEVICE(0x10C4, 0x82F2) }, /* CESINEL MEDCAL ST Network Analyzer */
123 	{ USB_DEVICE(0x10C4, 0x82F4) }, /* Starizona MicroTouch */
124 	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
125 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
126 	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
127 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
128 	{ USB_DEVICE(0x10C4, 0x83AA) }, /* Mark-10 Digital Force Gauge */
129 	{ USB_DEVICE(0x10C4, 0x83D8) }, /* DekTec DTA Plus VHF/UHF Booster/Attenuator */
130 	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
131 	{ USB_DEVICE(0x10C4, 0x8418) }, /* IRZ Automation Teleport SG-10 GSM/GPRS Modem */
132 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
133 	{ USB_DEVICE(0x10C4, 0x8470) }, /* Juniper Networks BX Series System Console */
134 	{ USB_DEVICE(0x10C4, 0x8477) }, /* Balluff RFID */
135 	{ USB_DEVICE(0x10C4, 0x84B6) }, /* Starizona Hyperion */
136 	{ USB_DEVICE(0x10C4, 0x851E) }, /* CESINEL MEDCAL PT Network Analyzer */
137 	{ USB_DEVICE(0x10C4, 0x85A7) }, /* LifeScan OneTouch Verio IQ */
138 	{ USB_DEVICE(0x10C4, 0x85B8) }, /* CESINEL ReCon T Energy Logger */
139 	{ USB_DEVICE(0x10C4, 0x85EA) }, /* AC-Services IBUS-IF */
140 	{ USB_DEVICE(0x10C4, 0x85EB) }, /* AC-Services CIS-IBUS */
141 	{ USB_DEVICE(0x10C4, 0x85F8) }, /* Virtenio Preon32 */
142 	{ USB_DEVICE(0x10C4, 0x8664) }, /* AC-Services CAN-IF */
143 	{ USB_DEVICE(0x10C4, 0x8665) }, /* AC-Services OBD-IF */
144 	{ USB_DEVICE(0x10C4, 0x8856) },	/* CEL EM357 ZigBee USB Stick - LR */
145 	{ USB_DEVICE(0x10C4, 0x8857) },	/* CEL EM357 ZigBee USB Stick */
146 	{ USB_DEVICE(0x10C4, 0x88A4) }, /* MMB Networks ZigBee USB Device */
147 	{ USB_DEVICE(0x10C4, 0x88A5) }, /* Planet Innovation Ingeni ZigBee USB Device */
148 	{ USB_DEVICE(0x10C4, 0x88D8) }, /* Acuity Brands nLight Air Adapter */
149 	{ USB_DEVICE(0x10C4, 0x88FB) }, /* CESINEL MEDCAL STII Network Analyzer */
150 	{ USB_DEVICE(0x10C4, 0x8938) }, /* CESINEL MEDCAL S II Network Analyzer */
151 	{ USB_DEVICE(0x10C4, 0x8946) }, /* Ketra N1 Wireless Interface */
152 	{ USB_DEVICE(0x10C4, 0x8962) }, /* Brim Brothers charging dock */
153 	{ USB_DEVICE(0x10C4, 0x8977) },	/* CEL MeshWorks DevKit Device */
154 	{ USB_DEVICE(0x10C4, 0x8998) }, /* KCF Technologies PRN */
155 	{ USB_DEVICE(0x10C4, 0x89A4) }, /* CESINEL FTBC Flexible Thyristor Bridge Controller */
156 	{ USB_DEVICE(0x10C4, 0x89FB) }, /* Qivicon ZigBee USB Radio Stick */
157 	{ USB_DEVICE(0x10C4, 0x8A2A) }, /* HubZ dual ZigBee and Z-Wave dongle */
158 	{ USB_DEVICE(0x10C4, 0x8A5B) }, /* CEL EM3588 ZigBee USB Stick */
159 	{ USB_DEVICE(0x10C4, 0x8A5E) }, /* CEL EM3588 ZigBee USB Stick Long Range */
160 	{ USB_DEVICE(0x10C4, 0x8B34) }, /* Qivicon ZigBee USB Radio Stick */
161 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
162 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
163 	{ USB_DEVICE(0x10C4, 0xEA63) }, /* Silicon Labs Windows Update (CP2101-4/CP2102N) */
164 	{ USB_DEVICE(0x10C4, 0xEA70) }, /* Silicon Labs factory default */
165 	{ USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
166 	{ USB_DEVICE(0x10C4, 0xEA7A) }, /* Silicon Labs Windows Update (CP2105) */
167 	{ USB_DEVICE(0x10C4, 0xEA7B) }, /* Silicon Labs Windows Update (CP2108) */
168 	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
169 	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
170 	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
171 	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
172 	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
173 	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
174 	{ USB_DEVICE(0x12B8, 0xEC60) }, /* Link G4 ECU */
175 	{ USB_DEVICE(0x12B8, 0xEC62) }, /* Link G4+ ECU */
176 	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
177 	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
178 	{ USB_DEVICE(0x155A, 0x1006) },	/* ELDAT Easywave RX09 */
179 	{ USB_DEVICE(0x166A, 0x0201) }, /* Clipsal 5500PACA C-Bus Pascal Automation Controller */
180 	{ USB_DEVICE(0x166A, 0x0301) }, /* Clipsal 5800PC C-Bus Wireless PC Interface */
181 	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
182 	{ USB_DEVICE(0x166A, 0x0304) }, /* Clipsal 5000CT2 C-Bus Black and White Touchscreen */
183 	{ USB_DEVICE(0x166A, 0x0305) }, /* Clipsal C-5000CT2 C-Bus Spectrum Colour Touchscreen */
184 	{ USB_DEVICE(0x166A, 0x0401) }, /* Clipsal L51xx C-Bus Architectural Dimmer */
185 	{ USB_DEVICE(0x166A, 0x0101) }, /* Clipsal 5560884 C-Bus Multi-room Audio Matrix Switcher */
186 	{ USB_DEVICE(0x16C0, 0x09B0) }, /* Lunatico Seletek */
187 	{ USB_DEVICE(0x16C0, 0x09B1) }, /* Lunatico Seletek */
188 	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
189 	{ USB_DEVICE(0x16DC, 0x0010) }, /* W-IE-NE-R Plein & Baus GmbH PL512 Power Supply */
190 	{ USB_DEVICE(0x16DC, 0x0011) }, /* W-IE-NE-R Plein & Baus GmbH RCM Remote Control for MARATON Power Supply */
191 	{ USB_DEVICE(0x16DC, 0x0012) }, /* W-IE-NE-R Plein & Baus GmbH MPOD Multi Channel Power Supply */
192 	{ USB_DEVICE(0x16DC, 0x0015) }, /* W-IE-NE-R Plein & Baus GmbH CML Control, Monitoring and Data Logger */
193 	{ USB_DEVICE(0x17A8, 0x0001) }, /* Kamstrup Optical Eye/3-wire */
194 	{ USB_DEVICE(0x17A8, 0x0005) }, /* Kamstrup M-Bus Master MultiPort 250D */
195 	{ USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
196 	{ USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
197 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
198 	{ USB_DEVICE(0x18EF, 0xE025) }, /* ELV Marble Sound Board 1 */
199 	{ USB_DEVICE(0x18EF, 0xE030) }, /* ELV ALC 8xxx Battery Charger */
200 	{ USB_DEVICE(0x18EF, 0xE032) }, /* ELV TFD500 Data Logger */
201 	{ USB_DEVICE(0x1901, 0x0190) }, /* GE B850 CP2105 Recorder interface */
202 	{ USB_DEVICE(0x1901, 0x0193) }, /* GE B650 CP2104 PMC interface */
203 	{ USB_DEVICE(0x1901, 0x0194) },	/* GE Healthcare Remote Alarm Box */
204 	{ USB_DEVICE(0x1901, 0x0195) },	/* GE B850/B650/B450 CP2104 DP UART interface */
205 	{ USB_DEVICE(0x1901, 0x0196) },	/* GE B850 CP2105 DP UART interface */
206 	{ USB_DEVICE(0x1901, 0x0197) }, /* GE CS1000 M.2 Key E serial interface */
207 	{ USB_DEVICE(0x1901, 0x0198) }, /* GE CS1000 Display serial interface */
208 	{ USB_DEVICE(0x199B, 0xBA30) }, /* LORD WSDA-200-USB */
209 	{ USB_DEVICE(0x19CF, 0x3000) }, /* Parrot NMEA GPS Flight Recorder */
210 	{ USB_DEVICE(0x1ADB, 0x0001) }, /* Schweitzer Engineering C662 Cable */
211 	{ USB_DEVICE(0x1B1C, 0x1C00) }, /* Corsair USB Dongle */
212 	{ USB_DEVICE(0x1BA4, 0x0002) },	/* Silicon Labs 358x factory default */
213 	{ USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */
214 	{ USB_DEVICE(0x1D6F, 0x0010) }, /* Seluxit ApS RF Dongle */
215 	{ USB_DEVICE(0x1E29, 0x0102) }, /* Festo CPX-USB */
216 	{ USB_DEVICE(0x1E29, 0x0501) }, /* Festo CMSP */
217 	{ USB_DEVICE(0x1FB9, 0x0100) }, /* Lake Shore Model 121 Current Source */
218 	{ USB_DEVICE(0x1FB9, 0x0200) }, /* Lake Shore Model 218A Temperature Monitor */
219 	{ USB_DEVICE(0x1FB9, 0x0201) }, /* Lake Shore Model 219 Temperature Monitor */
220 	{ USB_DEVICE(0x1FB9, 0x0202) }, /* Lake Shore Model 233 Temperature Transmitter */
221 	{ USB_DEVICE(0x1FB9, 0x0203) }, /* Lake Shore Model 235 Temperature Transmitter */
222 	{ USB_DEVICE(0x1FB9, 0x0300) }, /* Lake Shore Model 335 Temperature Controller */
223 	{ USB_DEVICE(0x1FB9, 0x0301) }, /* Lake Shore Model 336 Temperature Controller */
224 	{ USB_DEVICE(0x1FB9, 0x0302) }, /* Lake Shore Model 350 Temperature Controller */
225 	{ USB_DEVICE(0x1FB9, 0x0303) }, /* Lake Shore Model 371 AC Bridge */
226 	{ USB_DEVICE(0x1FB9, 0x0400) }, /* Lake Shore Model 411 Handheld Gaussmeter */
227 	{ USB_DEVICE(0x1FB9, 0x0401) }, /* Lake Shore Model 425 Gaussmeter */
228 	{ USB_DEVICE(0x1FB9, 0x0402) }, /* Lake Shore Model 455A Gaussmeter */
229 	{ USB_DEVICE(0x1FB9, 0x0403) }, /* Lake Shore Model 475A Gaussmeter */
230 	{ USB_DEVICE(0x1FB9, 0x0404) }, /* Lake Shore Model 465 Three Axis Gaussmeter */
231 	{ USB_DEVICE(0x1FB9, 0x0600) }, /* Lake Shore Model 625A Superconducting MPS */
232 	{ USB_DEVICE(0x1FB9, 0x0601) }, /* Lake Shore Model 642A Magnet Power Supply */
233 	{ USB_DEVICE(0x1FB9, 0x0602) }, /* Lake Shore Model 648 Magnet Power Supply */
234 	{ USB_DEVICE(0x1FB9, 0x0700) }, /* Lake Shore Model 737 VSM Controller */
235 	{ USB_DEVICE(0x1FB9, 0x0701) }, /* Lake Shore Model 776 Hall Matrix */
236 	{ USB_DEVICE(0x2184, 0x0030) }, /* GW Instek GDM-834x Digital Multimeter */
237 	{ USB_DEVICE(0x2626, 0xEA60) }, /* Aruba Networks 7xxx USB Serial Console */
238 	{ USB_DEVICE(0x3195, 0xF190) }, /* Link Instruments MSO-19 */
239 	{ USB_DEVICE(0x3195, 0xF280) }, /* Link Instruments MSO-28 */
240 	{ USB_DEVICE(0x3195, 0xF281) }, /* Link Instruments MSO-28 */
241 	{ USB_DEVICE(0x3923, 0x7A0B) }, /* National Instruments USB Serial Console */
242 	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
243 	{ } /* Terminating Entry */
244 };
245 
246 MODULE_DEVICE_TABLE(usb, id_table);
247 
248 struct cp210x_serial_private {
249 #ifdef CONFIG_GPIOLIB
250 	struct gpio_chip	gc;
251 	bool			gpio_registered;
252 	u16			gpio_pushpull;
253 	u16			gpio_altfunc;
254 	u16			gpio_input;
255 #endif
256 	u8			partnum;
257 	u32			fw_version;
258 	speed_t			min_speed;
259 	speed_t			max_speed;
260 	bool			use_actual_rate;
261 	bool			no_flow_control;
262 	bool			no_event_mode;
263 };
264 
265 enum cp210x_event_state {
266 	ES_DATA,
267 	ES_ESCAPE,
268 	ES_LSR,
269 	ES_LSR_DATA_0,
270 	ES_LSR_DATA_1,
271 	ES_MSR
272 };
273 
274 struct cp210x_port_private {
275 	u8			bInterfaceNumber;
276 	bool			event_mode;
277 	enum cp210x_event_state event_state;
278 	u8			lsr;
279 
280 	struct mutex		mutex;
281 	bool			crtscts;
282 	bool			dtr;
283 	bool			rts;
284 };
285 
286 static struct usb_serial_driver cp210x_device = {
287 	.driver = {
288 		.owner =	THIS_MODULE,
289 		.name =		"cp210x",
290 	},
291 	.id_table		= id_table,
292 	.num_ports		= 1,
293 	.bulk_in_size		= 256,
294 	.bulk_out_size		= 256,
295 	.open			= cp210x_open,
296 	.close			= cp210x_close,
297 	.break_ctl		= cp210x_break_ctl,
298 	.set_termios		= cp210x_set_termios,
299 	.tx_empty		= cp210x_tx_empty,
300 	.throttle		= usb_serial_generic_throttle,
301 	.unthrottle		= usb_serial_generic_unthrottle,
302 	.tiocmget		= cp210x_tiocmget,
303 	.tiocmset		= cp210x_tiocmset,
304 	.get_icount		= usb_serial_generic_get_icount,
305 	.attach			= cp210x_attach,
306 	.disconnect		= cp210x_disconnect,
307 	.release		= cp210x_release,
308 	.port_probe		= cp210x_port_probe,
309 	.port_remove		= cp210x_port_remove,
310 	.dtr_rts		= cp210x_dtr_rts,
311 	.process_read_urb	= cp210x_process_read_urb,
312 };
313 
314 static struct usb_serial_driver * const serial_drivers[] = {
315 	&cp210x_device, NULL
316 };
317 
318 /* Config request types */
319 #define REQTYPE_HOST_TO_INTERFACE	0x41
320 #define REQTYPE_INTERFACE_TO_HOST	0xc1
321 #define REQTYPE_HOST_TO_DEVICE	0x40
322 #define REQTYPE_DEVICE_TO_HOST	0xc0
323 
324 /* Config request codes */
325 #define CP210X_IFC_ENABLE	0x00
326 #define CP210X_SET_BAUDDIV	0x01
327 #define CP210X_GET_BAUDDIV	0x02
328 #define CP210X_SET_LINE_CTL	0x03
329 #define CP210X_GET_LINE_CTL	0x04
330 #define CP210X_SET_BREAK	0x05
331 #define CP210X_IMM_CHAR		0x06
332 #define CP210X_SET_MHS		0x07
333 #define CP210X_GET_MDMSTS	0x08
334 #define CP210X_SET_XON		0x09
335 #define CP210X_SET_XOFF		0x0A
336 #define CP210X_SET_EVENTMASK	0x0B
337 #define CP210X_GET_EVENTMASK	0x0C
338 #define CP210X_SET_CHAR		0x0D
339 #define CP210X_GET_CHARS	0x0E
340 #define CP210X_GET_PROPS	0x0F
341 #define CP210X_GET_COMM_STATUS	0x10
342 #define CP210X_RESET		0x11
343 #define CP210X_PURGE		0x12
344 #define CP210X_SET_FLOW		0x13
345 #define CP210X_GET_FLOW		0x14
346 #define CP210X_EMBED_EVENTS	0x15
347 #define CP210X_GET_EVENTSTATE	0x16
348 #define CP210X_SET_CHARS	0x19
349 #define CP210X_GET_BAUDRATE	0x1D
350 #define CP210X_SET_BAUDRATE	0x1E
351 #define CP210X_VENDOR_SPECIFIC	0xFF
352 
353 /* CP210X_IFC_ENABLE */
354 #define UART_ENABLE		0x0001
355 #define UART_DISABLE		0x0000
356 
357 /* CP210X_(SET|GET)_BAUDDIV */
358 #define BAUD_RATE_GEN_FREQ	0x384000
359 
360 /* CP210X_(SET|GET)_LINE_CTL */
361 #define BITS_DATA_MASK		0X0f00
362 #define BITS_DATA_5		0X0500
363 #define BITS_DATA_6		0X0600
364 #define BITS_DATA_7		0X0700
365 #define BITS_DATA_8		0X0800
366 #define BITS_DATA_9		0X0900
367 
368 #define BITS_PARITY_MASK	0x00f0
369 #define BITS_PARITY_NONE	0x0000
370 #define BITS_PARITY_ODD		0x0010
371 #define BITS_PARITY_EVEN	0x0020
372 #define BITS_PARITY_MARK	0x0030
373 #define BITS_PARITY_SPACE	0x0040
374 
375 #define BITS_STOP_MASK		0x000f
376 #define BITS_STOP_1		0x0000
377 #define BITS_STOP_1_5		0x0001
378 #define BITS_STOP_2		0x0002
379 
380 /* CP210X_SET_BREAK */
381 #define BREAK_ON		0x0001
382 #define BREAK_OFF		0x0000
383 
384 /* CP210X_(SET_MHS|GET_MDMSTS) */
385 #define CONTROL_DTR		0x0001
386 #define CONTROL_RTS		0x0002
387 #define CONTROL_CTS		0x0010
388 #define CONTROL_DSR		0x0020
389 #define CONTROL_RING		0x0040
390 #define CONTROL_DCD		0x0080
391 #define CONTROL_WRITE_DTR	0x0100
392 #define CONTROL_WRITE_RTS	0x0200
393 
394 /* CP210X_(GET|SET)_CHARS */
395 struct cp210x_special_chars {
396 	u8	bEofChar;
397 	u8	bErrorChar;
398 	u8	bBreakChar;
399 	u8	bEventChar;
400 	u8	bXonChar;
401 	u8	bXoffChar;
402 };
403 
404 /* CP210X_VENDOR_SPECIFIC values */
405 #define CP210X_GET_FW_VER	0x000E
406 #define CP210X_READ_2NCONFIG	0x000E
407 #define CP210X_GET_FW_VER_2N	0x0010
408 #define CP210X_READ_LATCH	0x00C2
409 #define CP210X_GET_PARTNUM	0x370B
410 #define CP210X_GET_PORTCONFIG	0x370C
411 #define CP210X_GET_DEVICEMODE	0x3711
412 #define CP210X_WRITE_LATCH	0x37E1
413 
414 /* Part number definitions */
415 #define CP210X_PARTNUM_CP2101	0x01
416 #define CP210X_PARTNUM_CP2102	0x02
417 #define CP210X_PARTNUM_CP2103	0x03
418 #define CP210X_PARTNUM_CP2104	0x04
419 #define CP210X_PARTNUM_CP2105	0x05
420 #define CP210X_PARTNUM_CP2108	0x08
421 #define CP210X_PARTNUM_CP2102N_QFN28	0x20
422 #define CP210X_PARTNUM_CP2102N_QFN24	0x21
423 #define CP210X_PARTNUM_CP2102N_QFN20	0x22
424 #define CP210X_PARTNUM_UNKNOWN	0xFF
425 
426 /* CP210X_GET_COMM_STATUS returns these 0x13 bytes */
427 struct cp210x_comm_status {
428 	__le32   ulErrors;
429 	__le32   ulHoldReasons;
430 	__le32   ulAmountInInQueue;
431 	__le32   ulAmountInOutQueue;
432 	u8       bEofReceived;
433 	u8       bWaitForImmediate;
434 	u8       bReserved;
435 } __packed;
436 
437 /*
438  * CP210X_PURGE - 16 bits passed in wValue of USB request.
439  * SiLabs app note AN571 gives a strange description of the 4 bits:
440  * bit 0 or bit 2 clears the transmit queue and 1 or 3 receive.
441  * writing 1 to all, however, purges cp2108 well enough to avoid the hang.
442  */
443 #define PURGE_ALL		0x000f
444 
445 /* CP210X_EMBED_EVENTS */
446 #define CP210X_ESCCHAR		0xec
447 
448 #define CP210X_LSR_OVERRUN	BIT(1)
449 #define CP210X_LSR_PARITY	BIT(2)
450 #define CP210X_LSR_FRAME	BIT(3)
451 #define CP210X_LSR_BREAK	BIT(4)
452 
453 
454 /* CP210X_GET_FLOW/CP210X_SET_FLOW read/write these 0x10 bytes */
455 struct cp210x_flow_ctl {
456 	__le32	ulControlHandshake;
457 	__le32	ulFlowReplace;
458 	__le32	ulXonLimit;
459 	__le32	ulXoffLimit;
460 };
461 
462 /* cp210x_flow_ctl::ulControlHandshake */
463 #define CP210X_SERIAL_DTR_MASK		GENMASK(1, 0)
464 #define CP210X_SERIAL_DTR_INACTIVE	(0 << 0)
465 #define CP210X_SERIAL_DTR_ACTIVE	(1 << 0)
466 #define CP210X_SERIAL_DTR_FLOW_CTL	(2 << 0)
467 #define CP210X_SERIAL_CTS_HANDSHAKE	BIT(3)
468 #define CP210X_SERIAL_DSR_HANDSHAKE	BIT(4)
469 #define CP210X_SERIAL_DCD_HANDSHAKE	BIT(5)
470 #define CP210X_SERIAL_DSR_SENSITIVITY	BIT(6)
471 
472 /* cp210x_flow_ctl::ulFlowReplace */
473 #define CP210X_SERIAL_AUTO_TRANSMIT	BIT(0)
474 #define CP210X_SERIAL_AUTO_RECEIVE	BIT(1)
475 #define CP210X_SERIAL_ERROR_CHAR	BIT(2)
476 #define CP210X_SERIAL_NULL_STRIPPING	BIT(3)
477 #define CP210X_SERIAL_BREAK_CHAR	BIT(4)
478 #define CP210X_SERIAL_RTS_MASK		GENMASK(7, 6)
479 #define CP210X_SERIAL_RTS_INACTIVE	(0 << 6)
480 #define CP210X_SERIAL_RTS_ACTIVE	(1 << 6)
481 #define CP210X_SERIAL_RTS_FLOW_CTL	(2 << 6)
482 #define CP210X_SERIAL_XOFF_CONTINUE	BIT(31)
483 
484 /* CP210X_VENDOR_SPECIFIC, CP210X_GET_DEVICEMODE call reads these 0x2 bytes. */
485 struct cp210x_pin_mode {
486 	u8	eci;
487 	u8	sci;
488 };
489 
490 #define CP210X_PIN_MODE_MODEM		0
491 #define CP210X_PIN_MODE_GPIO		BIT(0)
492 
493 /*
494  * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 0xf bytes
495  * on a CP2105 chip. Structure needs padding due to unused/unspecified bytes.
496  */
497 struct cp210x_dual_port_config {
498 	__le16	gpio_mode;
499 	u8	__pad0[2];
500 	__le16	reset_state;
501 	u8	__pad1[4];
502 	__le16	suspend_state;
503 	u8	sci_cfg;
504 	u8	eci_cfg;
505 	u8	device_cfg;
506 } __packed;
507 
508 /*
509  * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 0xd bytes
510  * on a CP2104 chip. Structure needs padding due to unused/unspecified bytes.
511  */
512 struct cp210x_single_port_config {
513 	__le16	gpio_mode;
514 	u8	__pad0[2];
515 	__le16	reset_state;
516 	u8	__pad1[4];
517 	__le16	suspend_state;
518 	u8	device_cfg;
519 } __packed;
520 
521 /* GPIO modes */
522 #define CP210X_SCI_GPIO_MODE_OFFSET	9
523 #define CP210X_SCI_GPIO_MODE_MASK	GENMASK(11, 9)
524 
525 #define CP210X_ECI_GPIO_MODE_OFFSET	2
526 #define CP210X_ECI_GPIO_MODE_MASK	GENMASK(3, 2)
527 
528 #define CP210X_GPIO_MODE_OFFSET		8
529 #define CP210X_GPIO_MODE_MASK		GENMASK(11, 8)
530 
531 /* CP2105 port configuration values */
532 #define CP2105_GPIO0_TXLED_MODE		BIT(0)
533 #define CP2105_GPIO1_RXLED_MODE		BIT(1)
534 #define CP2105_GPIO1_RS485_MODE		BIT(2)
535 
536 /* CP2104 port configuration values */
537 #define CP2104_GPIO0_TXLED_MODE		BIT(0)
538 #define CP2104_GPIO1_RXLED_MODE		BIT(1)
539 #define CP2104_GPIO2_RS485_MODE		BIT(2)
540 
541 struct cp210x_quad_port_state {
542 	__le16 gpio_mode_pb0;
543 	__le16 gpio_mode_pb1;
544 	__le16 gpio_mode_pb2;
545 	__le16 gpio_mode_pb3;
546 	__le16 gpio_mode_pb4;
547 
548 	__le16 gpio_lowpower_pb0;
549 	__le16 gpio_lowpower_pb1;
550 	__le16 gpio_lowpower_pb2;
551 	__le16 gpio_lowpower_pb3;
552 	__le16 gpio_lowpower_pb4;
553 
554 	__le16 gpio_latch_pb0;
555 	__le16 gpio_latch_pb1;
556 	__le16 gpio_latch_pb2;
557 	__le16 gpio_latch_pb3;
558 	__le16 gpio_latch_pb4;
559 };
560 
561 /*
562  * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 0x49 bytes
563  * on a CP2108 chip.
564  *
565  * See https://www.silabs.com/documents/public/application-notes/an978-cp210x-usb-to-uart-api-specification.pdf
566  */
567 struct cp210x_quad_port_config {
568 	struct cp210x_quad_port_state reset_state;
569 	struct cp210x_quad_port_state suspend_state;
570 	u8 ipdelay_ifc[4];
571 	u8 enhancedfxn_ifc[4];
572 	u8 enhancedfxn_device;
573 	u8 extclkfreq[4];
574 } __packed;
575 
576 #define CP2108_EF_IFC_GPIO_TXLED		0x01
577 #define CP2108_EF_IFC_GPIO_RXLED		0x02
578 #define CP2108_EF_IFC_GPIO_RS485		0x04
579 #define CP2108_EF_IFC_GPIO_RS485_LOGIC		0x08
580 #define CP2108_EF_IFC_GPIO_CLOCK		0x10
581 #define CP2108_EF_IFC_DYNAMIC_SUSPEND		0x40
582 
583 /* CP2102N configuration array indices */
584 #define CP210X_2NCONFIG_CONFIG_VERSION_IDX	2
585 #define CP210X_2NCONFIG_GPIO_MODE_IDX		581
586 #define CP210X_2NCONFIG_GPIO_RSTLATCH_IDX	587
587 #define CP210X_2NCONFIG_GPIO_CONTROL_IDX	600
588 
589 /* CP2102N QFN20 port configuration values */
590 #define CP2102N_QFN20_GPIO2_TXLED_MODE		BIT(2)
591 #define CP2102N_QFN20_GPIO3_RXLED_MODE		BIT(3)
592 #define CP2102N_QFN20_GPIO1_RS485_MODE		BIT(4)
593 #define CP2102N_QFN20_GPIO0_CLK_MODE		BIT(6)
594 
595 /*
596  * CP210X_VENDOR_SPECIFIC, CP210X_WRITE_LATCH call writes these 0x02 bytes
597  * for CP2102N, CP2103, CP2104 and CP2105.
598  */
599 struct cp210x_gpio_write {
600 	u8	mask;
601 	u8	state;
602 };
603 
604 /*
605  * CP210X_VENDOR_SPECIFIC, CP210X_WRITE_LATCH call writes these 0x04 bytes
606  * for CP2108.
607  */
608 struct cp210x_gpio_write16 {
609 	__le16	mask;
610 	__le16	state;
611 };
612 
613 /*
614  * Helper to get interface number when we only have struct usb_serial.
615  */
616 static u8 cp210x_interface_num(struct usb_serial *serial)
617 {
618 	struct usb_host_interface *cur_altsetting;
619 
620 	cur_altsetting = serial->interface->cur_altsetting;
621 
622 	return cur_altsetting->desc.bInterfaceNumber;
623 }
624 
625 /*
626  * Reads a variable-sized block of CP210X_ registers, identified by req.
627  * Returns data into buf in native USB byte order.
628  */
629 static int cp210x_read_reg_block(struct usb_serial_port *port, u8 req,
630 		void *buf, int bufsize)
631 {
632 	struct usb_serial *serial = port->serial;
633 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
634 	int result;
635 
636 
637 	result = usb_control_msg_recv(serial->dev, 0, req,
638 			REQTYPE_INTERFACE_TO_HOST, 0,
639 			port_priv->bInterfaceNumber, buf, bufsize,
640 			USB_CTRL_SET_TIMEOUT, GFP_KERNEL);
641 	if (result) {
642 		dev_err(&port->dev, "failed get req 0x%x size %d status: %d\n",
643 				req, bufsize, result);
644 		return result;
645 	}
646 
647 	return 0;
648 }
649 
650 /*
651  * Reads any 8-bit CP210X_ register identified by req.
652  */
653 static int cp210x_read_u8_reg(struct usb_serial_port *port, u8 req, u8 *val)
654 {
655 	return cp210x_read_reg_block(port, req, val, sizeof(*val));
656 }
657 
658 /*
659  * Reads a variable-sized vendor block of CP210X_ registers, identified by val.
660  * Returns data into buf in native USB byte order.
661  */
662 static int cp210x_read_vendor_block(struct usb_serial *serial, u8 type, u16 val,
663 				    void *buf, int bufsize)
664 {
665 	int result;
666 
667 	result = usb_control_msg_recv(serial->dev, 0, CP210X_VENDOR_SPECIFIC,
668 			type, val, cp210x_interface_num(serial), buf, bufsize,
669 			USB_CTRL_GET_TIMEOUT, GFP_KERNEL);
670 	if (result) {
671 		dev_err(&serial->interface->dev,
672 			"failed to get vendor val 0x%04x size %d: %d\n", val,
673 			bufsize, result);
674 		return result;
675 	}
676 
677 	return 0;
678 }
679 
680 /*
681  * Writes any 16-bit CP210X_ register (req) whose value is passed
682  * entirely in the wValue field of the USB request.
683  */
684 static int cp210x_write_u16_reg(struct usb_serial_port *port, u8 req, u16 val)
685 {
686 	struct usb_serial *serial = port->serial;
687 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
688 	int result;
689 
690 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
691 			req, REQTYPE_HOST_TO_INTERFACE, val,
692 			port_priv->bInterfaceNumber, NULL, 0,
693 			USB_CTRL_SET_TIMEOUT);
694 	if (result < 0) {
695 		dev_err(&port->dev, "failed set request 0x%x status: %d\n",
696 				req, result);
697 	}
698 
699 	return result;
700 }
701 
702 /*
703  * Writes a variable-sized block of CP210X_ registers, identified by req.
704  * Data in buf must be in native USB byte order.
705  */
706 static int cp210x_write_reg_block(struct usb_serial_port *port, u8 req,
707 		void *buf, int bufsize)
708 {
709 	struct usb_serial *serial = port->serial;
710 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
711 	int result;
712 
713 	result = usb_control_msg_send(serial->dev, 0, req,
714 			REQTYPE_HOST_TO_INTERFACE, 0,
715 			port_priv->bInterfaceNumber, buf, bufsize,
716 			USB_CTRL_SET_TIMEOUT, GFP_KERNEL);
717 	if (result) {
718 		dev_err(&port->dev, "failed set req 0x%x size %d status: %d\n",
719 				req, bufsize, result);
720 		return result;
721 	}
722 
723 	return 0;
724 }
725 
726 /*
727  * Writes any 32-bit CP210X_ register identified by req.
728  */
729 static int cp210x_write_u32_reg(struct usb_serial_port *port, u8 req, u32 val)
730 {
731 	__le32 le32_val;
732 
733 	le32_val = cpu_to_le32(val);
734 
735 	return cp210x_write_reg_block(port, req, &le32_val, sizeof(le32_val));
736 }
737 
738 #ifdef CONFIG_GPIOLIB
739 /*
740  * Writes a variable-sized vendor block of CP210X_ registers, identified by val.
741  * Data in buf must be in native USB byte order.
742  */
743 static int cp210x_write_vendor_block(struct usb_serial *serial, u8 type,
744 				     u16 val, void *buf, int bufsize)
745 {
746 	int result;
747 
748 	result = usb_control_msg_send(serial->dev, 0, CP210X_VENDOR_SPECIFIC,
749 			type, val, cp210x_interface_num(serial), buf, bufsize,
750 			USB_CTRL_SET_TIMEOUT, GFP_KERNEL);
751 	if (result) {
752 		dev_err(&serial->interface->dev,
753 			"failed to set vendor val 0x%04x size %d: %d\n", val,
754 			bufsize, result);
755 		return result;
756 	}
757 
758 	return 0;
759 }
760 #endif
761 
762 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
763 {
764 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
765 	int result;
766 
767 	result = cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_ENABLE);
768 	if (result) {
769 		dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
770 		return result;
771 	}
772 
773 	if (tty)
774 		cp210x_set_termios(tty, port, NULL);
775 
776 	result = usb_serial_generic_open(tty, port);
777 	if (result)
778 		goto err_disable;
779 
780 	return 0;
781 
782 err_disable:
783 	cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_DISABLE);
784 	port_priv->event_mode = false;
785 
786 	return result;
787 }
788 
789 static void cp210x_close(struct usb_serial_port *port)
790 {
791 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
792 
793 	usb_serial_generic_close(port);
794 
795 	/* Clear both queues; cp2108 needs this to avoid an occasional hang */
796 	cp210x_write_u16_reg(port, CP210X_PURGE, PURGE_ALL);
797 
798 	cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_DISABLE);
799 
800 	/* Disabling the interface disables event-insertion mode. */
801 	port_priv->event_mode = false;
802 }
803 
804 static void cp210x_process_lsr(struct usb_serial_port *port, unsigned char lsr, char *flag)
805 {
806 	if (lsr & CP210X_LSR_BREAK) {
807 		port->icount.brk++;
808 		*flag = TTY_BREAK;
809 	} else if (lsr & CP210X_LSR_PARITY) {
810 		port->icount.parity++;
811 		*flag = TTY_PARITY;
812 	} else if (lsr & CP210X_LSR_FRAME) {
813 		port->icount.frame++;
814 		*flag = TTY_FRAME;
815 	}
816 
817 	if (lsr & CP210X_LSR_OVERRUN) {
818 		port->icount.overrun++;
819 		tty_insert_flip_char(&port->port, 0, TTY_OVERRUN);
820 	}
821 }
822 
823 static bool cp210x_process_char(struct usb_serial_port *port, unsigned char *ch, char *flag)
824 {
825 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
826 
827 	switch (port_priv->event_state) {
828 	case ES_DATA:
829 		if (*ch == CP210X_ESCCHAR) {
830 			port_priv->event_state = ES_ESCAPE;
831 			break;
832 		}
833 		return false;
834 	case ES_ESCAPE:
835 		switch (*ch) {
836 		case 0:
837 			dev_dbg(&port->dev, "%s - escape char\n", __func__);
838 			*ch = CP210X_ESCCHAR;
839 			port_priv->event_state = ES_DATA;
840 			return false;
841 		case 1:
842 			port_priv->event_state = ES_LSR_DATA_0;
843 			break;
844 		case 2:
845 			port_priv->event_state = ES_LSR;
846 			break;
847 		case 3:
848 			port_priv->event_state = ES_MSR;
849 			break;
850 		default:
851 			dev_err(&port->dev, "malformed event 0x%02x\n", *ch);
852 			port_priv->event_state = ES_DATA;
853 			break;
854 		}
855 		break;
856 	case ES_LSR_DATA_0:
857 		port_priv->lsr = *ch;
858 		port_priv->event_state = ES_LSR_DATA_1;
859 		break;
860 	case ES_LSR_DATA_1:
861 		dev_dbg(&port->dev, "%s - lsr = 0x%02x, data = 0x%02x\n",
862 				__func__, port_priv->lsr, *ch);
863 		cp210x_process_lsr(port, port_priv->lsr, flag);
864 		port_priv->event_state = ES_DATA;
865 		return false;
866 	case ES_LSR:
867 		dev_dbg(&port->dev, "%s - lsr = 0x%02x\n", __func__, *ch);
868 		port_priv->lsr = *ch;
869 		cp210x_process_lsr(port, port_priv->lsr, flag);
870 		port_priv->event_state = ES_DATA;
871 		break;
872 	case ES_MSR:
873 		dev_dbg(&port->dev, "%s - msr = 0x%02x\n", __func__, *ch);
874 		/* unimplemented */
875 		port_priv->event_state = ES_DATA;
876 		break;
877 	}
878 
879 	return true;
880 }
881 
882 static void cp210x_process_read_urb(struct urb *urb)
883 {
884 	struct usb_serial_port *port = urb->context;
885 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
886 	unsigned char *ch = urb->transfer_buffer;
887 	char flag;
888 	int i;
889 
890 	if (!urb->actual_length)
891 		return;
892 
893 	if (port_priv->event_mode) {
894 		for (i = 0; i < urb->actual_length; i++, ch++) {
895 			flag = TTY_NORMAL;
896 
897 			if (cp210x_process_char(port, ch, &flag))
898 				continue;
899 
900 			tty_insert_flip_char(&port->port, *ch, flag);
901 		}
902 	} else {
903 		tty_insert_flip_string(&port->port, ch, urb->actual_length);
904 	}
905 	tty_flip_buffer_push(&port->port);
906 }
907 
908 /*
909  * Read how many bytes are waiting in the TX queue.
910  */
911 static int cp210x_get_tx_queue_byte_count(struct usb_serial_port *port,
912 		u32 *count)
913 {
914 	struct usb_serial *serial = port->serial;
915 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
916 	struct cp210x_comm_status sts;
917 	int result;
918 
919 	result = usb_control_msg_recv(serial->dev, 0, CP210X_GET_COMM_STATUS,
920 			REQTYPE_INTERFACE_TO_HOST, 0,
921 			port_priv->bInterfaceNumber, &sts, sizeof(sts),
922 			USB_CTRL_GET_TIMEOUT, GFP_KERNEL);
923 	if (result) {
924 		dev_err(&port->dev, "failed to get comm status: %d\n", result);
925 		return result;
926 	}
927 
928 	*count = le32_to_cpu(sts.ulAmountInOutQueue);
929 
930 	return 0;
931 }
932 
933 static bool cp210x_tx_empty(struct usb_serial_port *port)
934 {
935 	int err;
936 	u32 count;
937 
938 	err = cp210x_get_tx_queue_byte_count(port, &count);
939 	if (err)
940 		return true;
941 
942 	return !count;
943 }
944 
945 struct cp210x_rate {
946 	speed_t rate;
947 	speed_t high;
948 };
949 
950 static const struct cp210x_rate cp210x_an205_table1[] = {
951 	{ 300, 300 },
952 	{ 600, 600 },
953 	{ 1200, 1200 },
954 	{ 1800, 1800 },
955 	{ 2400, 2400 },
956 	{ 4000, 4000 },
957 	{ 4800, 4803 },
958 	{ 7200, 7207 },
959 	{ 9600, 9612 },
960 	{ 14400, 14428 },
961 	{ 16000, 16062 },
962 	{ 19200, 19250 },
963 	{ 28800, 28912 },
964 	{ 38400, 38601 },
965 	{ 51200, 51558 },
966 	{ 56000, 56280 },
967 	{ 57600, 58053 },
968 	{ 64000, 64111 },
969 	{ 76800, 77608 },
970 	{ 115200, 117028 },
971 	{ 128000, 129347 },
972 	{ 153600, 156868 },
973 	{ 230400, 237832 },
974 	{ 250000, 254234 },
975 	{ 256000, 273066 },
976 	{ 460800, 491520 },
977 	{ 500000, 567138 },
978 	{ 576000, 670254 },
979 	{ 921600, UINT_MAX }
980 };
981 
982 /*
983  * Quantises the baud rate as per AN205 Table 1
984  */
985 static speed_t cp210x_get_an205_rate(speed_t baud)
986 {
987 	int i;
988 
989 	for (i = 0; i < ARRAY_SIZE(cp210x_an205_table1); ++i) {
990 		if (baud <= cp210x_an205_table1[i].high)
991 			break;
992 	}
993 
994 	return cp210x_an205_table1[i].rate;
995 }
996 
997 static speed_t cp210x_get_actual_rate(speed_t baud)
998 {
999 	unsigned int prescale = 1;
1000 	unsigned int div;
1001 
1002 	if (baud <= 365)
1003 		prescale = 4;
1004 
1005 	div = DIV_ROUND_CLOSEST(48000000, 2 * prescale * baud);
1006 	baud = 48000000 / (2 * prescale * div);
1007 
1008 	return baud;
1009 }
1010 
1011 /*
1012  * CP2101 supports the following baud rates:
1013  *
1014  *	300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 28800,
1015  *	38400, 56000, 57600, 115200, 128000, 230400, 460800, 921600
1016  *
1017  * CP2102 and CP2103 support the following additional rates:
1018  *
1019  *	4000, 16000, 51200, 64000, 76800, 153600, 250000, 256000, 500000,
1020  *	576000
1021  *
1022  * The device will map a requested rate to a supported one, but the result
1023  * of requests for rates greater than 1053257 is undefined (see AN205).
1024  *
1025  * CP2104, CP2105 and CP2110 support most rates up to 2M, 921k and 1M baud,
1026  * respectively, with an error less than 1%. The actual rates are determined
1027  * by
1028  *
1029  *	div = round(freq / (2 x prescale x request))
1030  *	actual = freq / (2 x prescale x div)
1031  *
1032  * For CP2104 and CP2105 freq is 48Mhz and prescale is 4 for request <= 365bps
1033  * or 1 otherwise.
1034  * For CP2110 freq is 24Mhz and prescale is 4 for request <= 300bps or 1
1035  * otherwise.
1036  */
1037 static void cp210x_change_speed(struct tty_struct *tty,
1038 		struct usb_serial_port *port, struct ktermios *old_termios)
1039 {
1040 	struct usb_serial *serial = port->serial;
1041 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1042 	u32 baud;
1043 
1044 	/*
1045 	 * This maps the requested rate to the actual rate, a valid rate on
1046 	 * cp2102 or cp2103, or to an arbitrary rate in [1M, max_speed].
1047 	 *
1048 	 * NOTE: B0 is not implemented.
1049 	 */
1050 	baud = clamp(tty->termios.c_ospeed, priv->min_speed, priv->max_speed);
1051 
1052 	if (priv->use_actual_rate)
1053 		baud = cp210x_get_actual_rate(baud);
1054 	else if (baud < 1000000)
1055 		baud = cp210x_get_an205_rate(baud);
1056 
1057 	dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
1058 	if (cp210x_write_u32_reg(port, CP210X_SET_BAUDRATE, baud)) {
1059 		dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
1060 		if (old_termios)
1061 			baud = old_termios->c_ospeed;
1062 		else
1063 			baud = 9600;
1064 	}
1065 
1066 	tty_encode_baud_rate(tty, baud, baud);
1067 }
1068 
1069 static void cp210x_enable_event_mode(struct usb_serial_port *port)
1070 {
1071 	struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
1072 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
1073 	int ret;
1074 
1075 	if (port_priv->event_mode)
1076 		return;
1077 
1078 	if (priv->no_event_mode)
1079 		return;
1080 
1081 	port_priv->event_state = ES_DATA;
1082 	port_priv->event_mode = true;
1083 
1084 	ret = cp210x_write_u16_reg(port, CP210X_EMBED_EVENTS, CP210X_ESCCHAR);
1085 	if (ret) {
1086 		dev_err(&port->dev, "failed to enable events: %d\n", ret);
1087 		port_priv->event_mode = false;
1088 	}
1089 }
1090 
1091 static void cp210x_disable_event_mode(struct usb_serial_port *port)
1092 {
1093 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
1094 	int ret;
1095 
1096 	if (!port_priv->event_mode)
1097 		return;
1098 
1099 	ret = cp210x_write_u16_reg(port, CP210X_EMBED_EVENTS, 0);
1100 	if (ret) {
1101 		dev_err(&port->dev, "failed to disable events: %d\n", ret);
1102 		return;
1103 	}
1104 
1105 	port_priv->event_mode = false;
1106 }
1107 
1108 static bool cp210x_termios_change(const struct ktermios *a, const struct ktermios *b)
1109 {
1110 	bool iflag_change, cc_change;
1111 
1112 	iflag_change = ((a->c_iflag ^ b->c_iflag) & (INPCK | IXON | IXOFF));
1113 	cc_change = a->c_cc[VSTART] != b->c_cc[VSTART] ||
1114 			a->c_cc[VSTOP] != b->c_cc[VSTOP];
1115 
1116 	return tty_termios_hw_change(a, b) || iflag_change || cc_change;
1117 }
1118 
1119 static void cp210x_set_flow_control(struct tty_struct *tty,
1120 		struct usb_serial_port *port, struct ktermios *old_termios)
1121 {
1122 	struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
1123 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
1124 	struct cp210x_special_chars chars;
1125 	struct cp210x_flow_ctl flow_ctl;
1126 	u32 flow_repl;
1127 	u32 ctl_hs;
1128 	bool crtscts;
1129 	int ret;
1130 
1131 	/*
1132 	 * Some CP2102N interpret ulXonLimit as ulFlowReplace (erratum
1133 	 * CP2102N_E104). Report back that flow control is not supported.
1134 	 */
1135 	if (priv->no_flow_control) {
1136 		tty->termios.c_cflag &= ~CRTSCTS;
1137 		tty->termios.c_iflag &= ~(IXON | IXOFF);
1138 	}
1139 
1140 	if (old_termios &&
1141 			C_CRTSCTS(tty) == (old_termios->c_cflag & CRTSCTS) &&
1142 			I_IXON(tty) == (old_termios->c_iflag & IXON) &&
1143 			I_IXOFF(tty) == (old_termios->c_iflag & IXOFF) &&
1144 			START_CHAR(tty) == old_termios->c_cc[VSTART] &&
1145 			STOP_CHAR(tty) == old_termios->c_cc[VSTOP]) {
1146 		return;
1147 	}
1148 
1149 	if (I_IXON(tty) || I_IXOFF(tty)) {
1150 		memset(&chars, 0, sizeof(chars));
1151 
1152 		chars.bXonChar = START_CHAR(tty);
1153 		chars.bXoffChar = STOP_CHAR(tty);
1154 
1155 		ret = cp210x_write_reg_block(port, CP210X_SET_CHARS, &chars,
1156 				sizeof(chars));
1157 		if (ret) {
1158 			dev_err(&port->dev, "failed to set special chars: %d\n",
1159 					ret);
1160 		}
1161 	}
1162 
1163 	mutex_lock(&port_priv->mutex);
1164 
1165 	ret = cp210x_read_reg_block(port, CP210X_GET_FLOW, &flow_ctl,
1166 			sizeof(flow_ctl));
1167 	if (ret)
1168 		goto out_unlock;
1169 
1170 	ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake);
1171 	flow_repl = le32_to_cpu(flow_ctl.ulFlowReplace);
1172 
1173 	ctl_hs &= ~CP210X_SERIAL_DSR_HANDSHAKE;
1174 	ctl_hs &= ~CP210X_SERIAL_DCD_HANDSHAKE;
1175 	ctl_hs &= ~CP210X_SERIAL_DSR_SENSITIVITY;
1176 	ctl_hs &= ~CP210X_SERIAL_DTR_MASK;
1177 	if (port_priv->dtr)
1178 		ctl_hs |= CP210X_SERIAL_DTR_ACTIVE;
1179 	else
1180 		ctl_hs |= CP210X_SERIAL_DTR_INACTIVE;
1181 
1182 	flow_repl &= ~CP210X_SERIAL_RTS_MASK;
1183 	if (C_CRTSCTS(tty)) {
1184 		ctl_hs |= CP210X_SERIAL_CTS_HANDSHAKE;
1185 		if (port_priv->rts)
1186 			flow_repl |= CP210X_SERIAL_RTS_FLOW_CTL;
1187 		else
1188 			flow_repl |= CP210X_SERIAL_RTS_INACTIVE;
1189 		crtscts = true;
1190 	} else {
1191 		ctl_hs &= ~CP210X_SERIAL_CTS_HANDSHAKE;
1192 		if (port_priv->rts)
1193 			flow_repl |= CP210X_SERIAL_RTS_ACTIVE;
1194 		else
1195 			flow_repl |= CP210X_SERIAL_RTS_INACTIVE;
1196 		crtscts = false;
1197 	}
1198 
1199 	if (I_IXOFF(tty)) {
1200 		flow_repl |= CP210X_SERIAL_AUTO_RECEIVE;
1201 
1202 		flow_ctl.ulXonLimit = cpu_to_le32(128);
1203 		flow_ctl.ulXoffLimit = cpu_to_le32(128);
1204 	} else {
1205 		flow_repl &= ~CP210X_SERIAL_AUTO_RECEIVE;
1206 	}
1207 
1208 	if (I_IXON(tty))
1209 		flow_repl |= CP210X_SERIAL_AUTO_TRANSMIT;
1210 	else
1211 		flow_repl &= ~CP210X_SERIAL_AUTO_TRANSMIT;
1212 
1213 	dev_dbg(&port->dev, "%s - ctrl = 0x%02x, flow = 0x%02x\n", __func__,
1214 			ctl_hs, flow_repl);
1215 
1216 	flow_ctl.ulControlHandshake = cpu_to_le32(ctl_hs);
1217 	flow_ctl.ulFlowReplace = cpu_to_le32(flow_repl);
1218 
1219 	ret = cp210x_write_reg_block(port, CP210X_SET_FLOW, &flow_ctl,
1220 			sizeof(flow_ctl));
1221 	if (ret)
1222 		goto out_unlock;
1223 
1224 	port_priv->crtscts = crtscts;
1225 out_unlock:
1226 	mutex_unlock(&port_priv->mutex);
1227 }
1228 
1229 static void cp210x_set_termios(struct tty_struct *tty,
1230 		struct usb_serial_port *port, struct ktermios *old_termios)
1231 {
1232 	struct cp210x_serial_private *priv = usb_get_serial_data(port->serial);
1233 	u16 bits;
1234 	int ret;
1235 
1236 	if (old_termios && !cp210x_termios_change(&tty->termios, old_termios))
1237 		return;
1238 
1239 	if (!old_termios || tty->termios.c_ospeed != old_termios->c_ospeed)
1240 		cp210x_change_speed(tty, port, old_termios);
1241 
1242 	/* CP2101 only supports CS8, 1 stop bit and non-stick parity. */
1243 	if (priv->partnum == CP210X_PARTNUM_CP2101) {
1244 		tty->termios.c_cflag &= ~(CSIZE | CSTOPB | CMSPAR);
1245 		tty->termios.c_cflag |= CS8;
1246 	}
1247 
1248 	bits = 0;
1249 
1250 	switch (C_CSIZE(tty)) {
1251 	case CS5:
1252 		bits |= BITS_DATA_5;
1253 		break;
1254 	case CS6:
1255 		bits |= BITS_DATA_6;
1256 		break;
1257 	case CS7:
1258 		bits |= BITS_DATA_7;
1259 		break;
1260 	case CS8:
1261 	default:
1262 		bits |= BITS_DATA_8;
1263 		break;
1264 	}
1265 
1266 	if (C_PARENB(tty)) {
1267 		if (C_CMSPAR(tty)) {
1268 			if (C_PARODD(tty))
1269 				bits |= BITS_PARITY_MARK;
1270 			else
1271 				bits |= BITS_PARITY_SPACE;
1272 		} else {
1273 			if (C_PARODD(tty))
1274 				bits |= BITS_PARITY_ODD;
1275 			else
1276 				bits |= BITS_PARITY_EVEN;
1277 		}
1278 	}
1279 
1280 	if (C_CSTOPB(tty))
1281 		bits |= BITS_STOP_2;
1282 	else
1283 		bits |= BITS_STOP_1;
1284 
1285 	ret = cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
1286 	if (ret)
1287 		dev_err(&port->dev, "failed to set line control: %d\n", ret);
1288 
1289 	cp210x_set_flow_control(tty, port, old_termios);
1290 
1291 	/*
1292 	 * Enable event-insertion mode only if input parity checking is
1293 	 * enabled for now.
1294 	 */
1295 	if (I_INPCK(tty))
1296 		cp210x_enable_event_mode(port);
1297 	else
1298 		cp210x_disable_event_mode(port);
1299 }
1300 
1301 static int cp210x_tiocmset(struct tty_struct *tty,
1302 		unsigned int set, unsigned int clear)
1303 {
1304 	struct usb_serial_port *port = tty->driver_data;
1305 	return cp210x_tiocmset_port(port, set, clear);
1306 }
1307 
1308 static int cp210x_tiocmset_port(struct usb_serial_port *port,
1309 		unsigned int set, unsigned int clear)
1310 {
1311 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
1312 	struct cp210x_flow_ctl flow_ctl;
1313 	u32 ctl_hs, flow_repl;
1314 	u16 control = 0;
1315 	int ret;
1316 
1317 	mutex_lock(&port_priv->mutex);
1318 
1319 	if (set & TIOCM_RTS) {
1320 		port_priv->rts = true;
1321 		control |= CONTROL_RTS;
1322 		control |= CONTROL_WRITE_RTS;
1323 	}
1324 	if (set & TIOCM_DTR) {
1325 		port_priv->dtr = true;
1326 		control |= CONTROL_DTR;
1327 		control |= CONTROL_WRITE_DTR;
1328 	}
1329 	if (clear & TIOCM_RTS) {
1330 		port_priv->rts = false;
1331 		control &= ~CONTROL_RTS;
1332 		control |= CONTROL_WRITE_RTS;
1333 	}
1334 	if (clear & TIOCM_DTR) {
1335 		port_priv->dtr = false;
1336 		control &= ~CONTROL_DTR;
1337 		control |= CONTROL_WRITE_DTR;
1338 	}
1339 
1340 	/*
1341 	 * Use SET_FLOW to set DTR and enable/disable auto-RTS when hardware
1342 	 * flow control is enabled.
1343 	 */
1344 	if (port_priv->crtscts && control & CONTROL_WRITE_RTS) {
1345 		ret = cp210x_read_reg_block(port, CP210X_GET_FLOW, &flow_ctl,
1346 				sizeof(flow_ctl));
1347 		if (ret)
1348 			goto out_unlock;
1349 
1350 		ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake);
1351 		flow_repl = le32_to_cpu(flow_ctl.ulFlowReplace);
1352 
1353 		ctl_hs &= ~CP210X_SERIAL_DTR_MASK;
1354 		if (port_priv->dtr)
1355 			ctl_hs |= CP210X_SERIAL_DTR_ACTIVE;
1356 		else
1357 			ctl_hs |= CP210X_SERIAL_DTR_INACTIVE;
1358 
1359 		flow_repl &= ~CP210X_SERIAL_RTS_MASK;
1360 		if (port_priv->rts)
1361 			flow_repl |= CP210X_SERIAL_RTS_FLOW_CTL;
1362 		else
1363 			flow_repl |= CP210X_SERIAL_RTS_INACTIVE;
1364 
1365 		flow_ctl.ulControlHandshake = cpu_to_le32(ctl_hs);
1366 		flow_ctl.ulFlowReplace = cpu_to_le32(flow_repl);
1367 
1368 		dev_dbg(&port->dev, "%s - ctrl = 0x%02x, flow = 0x%02x\n",
1369 				__func__, ctl_hs, flow_repl);
1370 
1371 		ret = cp210x_write_reg_block(port, CP210X_SET_FLOW, &flow_ctl,
1372 				sizeof(flow_ctl));
1373 	} else {
1374 		dev_dbg(&port->dev, "%s - control = 0x%04x\n", __func__, control);
1375 
1376 		ret = cp210x_write_u16_reg(port, CP210X_SET_MHS, control);
1377 	}
1378 out_unlock:
1379 	mutex_unlock(&port_priv->mutex);
1380 
1381 	return ret;
1382 }
1383 
1384 static void cp210x_dtr_rts(struct usb_serial_port *port, int on)
1385 {
1386 	if (on)
1387 		cp210x_tiocmset_port(port, TIOCM_DTR | TIOCM_RTS, 0);
1388 	else
1389 		cp210x_tiocmset_port(port, 0, TIOCM_DTR | TIOCM_RTS);
1390 }
1391 
1392 static int cp210x_tiocmget(struct tty_struct *tty)
1393 {
1394 	struct usb_serial_port *port = tty->driver_data;
1395 	u8 control;
1396 	int result;
1397 
1398 	result = cp210x_read_u8_reg(port, CP210X_GET_MDMSTS, &control);
1399 	if (result)
1400 		return result;
1401 
1402 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
1403 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
1404 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
1405 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
1406 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
1407 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
1408 
1409 	dev_dbg(&port->dev, "%s - control = 0x%02x\n", __func__, control);
1410 
1411 	return result;
1412 }
1413 
1414 static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
1415 {
1416 	struct usb_serial_port *port = tty->driver_data;
1417 	u16 state;
1418 
1419 	if (break_state == 0)
1420 		state = BREAK_OFF;
1421 	else
1422 		state = BREAK_ON;
1423 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
1424 		state == BREAK_OFF ? "off" : "on");
1425 	cp210x_write_u16_reg(port, CP210X_SET_BREAK, state);
1426 }
1427 
1428 #ifdef CONFIG_GPIOLIB
1429 static int cp210x_gpio_get(struct gpio_chip *gc, unsigned int gpio)
1430 {
1431 	struct usb_serial *serial = gpiochip_get_data(gc);
1432 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1433 	u8 req_type;
1434 	u16 mask;
1435 	int result;
1436 	int len;
1437 
1438 	result = usb_autopm_get_interface(serial->interface);
1439 	if (result)
1440 		return result;
1441 
1442 	switch (priv->partnum) {
1443 	case CP210X_PARTNUM_CP2105:
1444 		req_type = REQTYPE_INTERFACE_TO_HOST;
1445 		len = 1;
1446 		break;
1447 	case CP210X_PARTNUM_CP2108:
1448 		req_type = REQTYPE_INTERFACE_TO_HOST;
1449 		len = 2;
1450 		break;
1451 	default:
1452 		req_type = REQTYPE_DEVICE_TO_HOST;
1453 		len = 1;
1454 		break;
1455 	}
1456 
1457 	mask = 0;
1458 	result = cp210x_read_vendor_block(serial, req_type, CP210X_READ_LATCH,
1459 					  &mask, len);
1460 
1461 	usb_autopm_put_interface(serial->interface);
1462 
1463 	if (result < 0)
1464 		return result;
1465 
1466 	le16_to_cpus(&mask);
1467 
1468 	return !!(mask & BIT(gpio));
1469 }
1470 
1471 static void cp210x_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
1472 {
1473 	struct usb_serial *serial = gpiochip_get_data(gc);
1474 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1475 	struct cp210x_gpio_write16 buf16;
1476 	struct cp210x_gpio_write buf;
1477 	u16 mask, state;
1478 	u16 wIndex;
1479 	int result;
1480 
1481 	if (value == 1)
1482 		state = BIT(gpio);
1483 	else
1484 		state = 0;
1485 
1486 	mask = BIT(gpio);
1487 
1488 	result = usb_autopm_get_interface(serial->interface);
1489 	if (result)
1490 		goto out;
1491 
1492 	switch (priv->partnum) {
1493 	case CP210X_PARTNUM_CP2105:
1494 		buf.mask = (u8)mask;
1495 		buf.state = (u8)state;
1496 		result = cp210x_write_vendor_block(serial,
1497 						   REQTYPE_HOST_TO_INTERFACE,
1498 						   CP210X_WRITE_LATCH, &buf,
1499 						   sizeof(buf));
1500 		break;
1501 	case CP210X_PARTNUM_CP2108:
1502 		buf16.mask = cpu_to_le16(mask);
1503 		buf16.state = cpu_to_le16(state);
1504 		result = cp210x_write_vendor_block(serial,
1505 						   REQTYPE_HOST_TO_INTERFACE,
1506 						   CP210X_WRITE_LATCH, &buf16,
1507 						   sizeof(buf16));
1508 		break;
1509 	default:
1510 		wIndex = state << 8 | mask;
1511 		result = usb_control_msg(serial->dev,
1512 					 usb_sndctrlpipe(serial->dev, 0),
1513 					 CP210X_VENDOR_SPECIFIC,
1514 					 REQTYPE_HOST_TO_DEVICE,
1515 					 CP210X_WRITE_LATCH,
1516 					 wIndex,
1517 					 NULL, 0, USB_CTRL_SET_TIMEOUT);
1518 		break;
1519 	}
1520 
1521 	usb_autopm_put_interface(serial->interface);
1522 out:
1523 	if (result < 0) {
1524 		dev_err(&serial->interface->dev, "failed to set GPIO value: %d\n",
1525 				result);
1526 	}
1527 }
1528 
1529 static int cp210x_gpio_direction_get(struct gpio_chip *gc, unsigned int gpio)
1530 {
1531 	struct usb_serial *serial = gpiochip_get_data(gc);
1532 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1533 
1534 	return priv->gpio_input & BIT(gpio);
1535 }
1536 
1537 static int cp210x_gpio_direction_input(struct gpio_chip *gc, unsigned int gpio)
1538 {
1539 	struct usb_serial *serial = gpiochip_get_data(gc);
1540 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1541 
1542 	if (priv->partnum == CP210X_PARTNUM_CP2105) {
1543 		/* hardware does not support an input mode */
1544 		return -ENOTSUPP;
1545 	}
1546 
1547 	/* push-pull pins cannot be changed to be inputs */
1548 	if (priv->gpio_pushpull & BIT(gpio))
1549 		return -EINVAL;
1550 
1551 	/* make sure to release pin if it is being driven low */
1552 	cp210x_gpio_set(gc, gpio, 1);
1553 
1554 	priv->gpio_input |= BIT(gpio);
1555 
1556 	return 0;
1557 }
1558 
1559 static int cp210x_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio,
1560 					int value)
1561 {
1562 	struct usb_serial *serial = gpiochip_get_data(gc);
1563 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1564 
1565 	priv->gpio_input &= ~BIT(gpio);
1566 	cp210x_gpio_set(gc, gpio, value);
1567 
1568 	return 0;
1569 }
1570 
1571 static int cp210x_gpio_set_config(struct gpio_chip *gc, unsigned int gpio,
1572 				  unsigned long config)
1573 {
1574 	struct usb_serial *serial = gpiochip_get_data(gc);
1575 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1576 	enum pin_config_param param = pinconf_to_config_param(config);
1577 
1578 	/* Succeed only if in correct mode (this can't be set at runtime) */
1579 	if ((param == PIN_CONFIG_DRIVE_PUSH_PULL) &&
1580 	    (priv->gpio_pushpull & BIT(gpio)))
1581 		return 0;
1582 
1583 	if ((param == PIN_CONFIG_DRIVE_OPEN_DRAIN) &&
1584 	    !(priv->gpio_pushpull & BIT(gpio)))
1585 		return 0;
1586 
1587 	return -ENOTSUPP;
1588 }
1589 
1590 static int cp210x_gpio_init_valid_mask(struct gpio_chip *gc,
1591 		unsigned long *valid_mask, unsigned int ngpios)
1592 {
1593 	struct usb_serial *serial = gpiochip_get_data(gc);
1594 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1595 	struct device *dev = &serial->interface->dev;
1596 	unsigned long altfunc_mask = priv->gpio_altfunc;
1597 
1598 	bitmap_complement(valid_mask, &altfunc_mask, ngpios);
1599 
1600 	if (bitmap_empty(valid_mask, ngpios))
1601 		dev_dbg(dev, "no pin configured for GPIO\n");
1602 	else
1603 		dev_dbg(dev, "GPIO.%*pbl configured for GPIO\n", ngpios,
1604 				valid_mask);
1605 	return 0;
1606 }
1607 
1608 /*
1609  * This function is for configuring GPIO using shared pins, where other signals
1610  * are made unavailable by configuring the use of GPIO. This is believed to be
1611  * only applicable to the cp2105 at this point, the other devices supported by
1612  * this driver that provide GPIO do so in a way that does not impact other
1613  * signals and are thus expected to have very different initialisation.
1614  */
1615 static int cp2105_gpioconf_init(struct usb_serial *serial)
1616 {
1617 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1618 	struct cp210x_pin_mode mode;
1619 	struct cp210x_dual_port_config config;
1620 	u8 intf_num = cp210x_interface_num(serial);
1621 	u8 iface_config;
1622 	int result;
1623 
1624 	result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
1625 					  CP210X_GET_DEVICEMODE, &mode,
1626 					  sizeof(mode));
1627 	if (result < 0)
1628 		return result;
1629 
1630 	result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
1631 					  CP210X_GET_PORTCONFIG, &config,
1632 					  sizeof(config));
1633 	if (result < 0)
1634 		return result;
1635 
1636 	/*  2 banks of GPIO - One for the pins taken from each serial port */
1637 	if (intf_num == 0) {
1638 		priv->gc.ngpio = 2;
1639 
1640 		if (mode.eci == CP210X_PIN_MODE_MODEM) {
1641 			/* mark all GPIOs of this interface as reserved */
1642 			priv->gpio_altfunc = 0xff;
1643 			return 0;
1644 		}
1645 
1646 		iface_config = config.eci_cfg;
1647 		priv->gpio_pushpull = (u8)((le16_to_cpu(config.gpio_mode) &
1648 						CP210X_ECI_GPIO_MODE_MASK) >>
1649 						CP210X_ECI_GPIO_MODE_OFFSET);
1650 	} else if (intf_num == 1) {
1651 		priv->gc.ngpio = 3;
1652 
1653 		if (mode.sci == CP210X_PIN_MODE_MODEM) {
1654 			/* mark all GPIOs of this interface as reserved */
1655 			priv->gpio_altfunc = 0xff;
1656 			return 0;
1657 		}
1658 
1659 		iface_config = config.sci_cfg;
1660 		priv->gpio_pushpull = (u8)((le16_to_cpu(config.gpio_mode) &
1661 						CP210X_SCI_GPIO_MODE_MASK) >>
1662 						CP210X_SCI_GPIO_MODE_OFFSET);
1663 	} else {
1664 		return -ENODEV;
1665 	}
1666 
1667 	/* mark all pins which are not in GPIO mode */
1668 	if (iface_config & CP2105_GPIO0_TXLED_MODE)	/* GPIO 0 */
1669 		priv->gpio_altfunc |= BIT(0);
1670 	if (iface_config & (CP2105_GPIO1_RXLED_MODE |	/* GPIO 1 */
1671 			CP2105_GPIO1_RS485_MODE))
1672 		priv->gpio_altfunc |= BIT(1);
1673 
1674 	/* driver implementation for CP2105 only supports outputs */
1675 	priv->gpio_input = 0;
1676 
1677 	return 0;
1678 }
1679 
1680 static int cp2104_gpioconf_init(struct usb_serial *serial)
1681 {
1682 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1683 	struct cp210x_single_port_config config;
1684 	u8 iface_config;
1685 	u8 gpio_latch;
1686 	int result;
1687 	u8 i;
1688 
1689 	result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
1690 					  CP210X_GET_PORTCONFIG, &config,
1691 					  sizeof(config));
1692 	if (result < 0)
1693 		return result;
1694 
1695 	priv->gc.ngpio = 4;
1696 
1697 	iface_config = config.device_cfg;
1698 	priv->gpio_pushpull = (u8)((le16_to_cpu(config.gpio_mode) &
1699 					CP210X_GPIO_MODE_MASK) >>
1700 					CP210X_GPIO_MODE_OFFSET);
1701 	gpio_latch = (u8)((le16_to_cpu(config.reset_state) &
1702 					CP210X_GPIO_MODE_MASK) >>
1703 					CP210X_GPIO_MODE_OFFSET);
1704 
1705 	/* mark all pins which are not in GPIO mode */
1706 	if (iface_config & CP2104_GPIO0_TXLED_MODE)	/* GPIO 0 */
1707 		priv->gpio_altfunc |= BIT(0);
1708 	if (iface_config & CP2104_GPIO1_RXLED_MODE)	/* GPIO 1 */
1709 		priv->gpio_altfunc |= BIT(1);
1710 	if (iface_config & CP2104_GPIO2_RS485_MODE)	/* GPIO 2 */
1711 		priv->gpio_altfunc |= BIT(2);
1712 
1713 	/*
1714 	 * Like CP2102N, CP2104 has also no strict input and output pin
1715 	 * modes.
1716 	 * Do the same input mode emulation as CP2102N.
1717 	 */
1718 	for (i = 0; i < priv->gc.ngpio; ++i) {
1719 		/*
1720 		 * Set direction to "input" iff pin is open-drain and reset
1721 		 * value is 1.
1722 		 */
1723 		if (!(priv->gpio_pushpull & BIT(i)) && (gpio_latch & BIT(i)))
1724 			priv->gpio_input |= BIT(i);
1725 	}
1726 
1727 	return 0;
1728 }
1729 
1730 static int cp2108_gpio_init(struct usb_serial *serial)
1731 {
1732 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1733 	struct cp210x_quad_port_config config;
1734 	u16 gpio_latch;
1735 	int result;
1736 	u8 i;
1737 
1738 	result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
1739 					  CP210X_GET_PORTCONFIG, &config,
1740 					  sizeof(config));
1741 	if (result < 0)
1742 		return result;
1743 
1744 	priv->gc.ngpio = 16;
1745 	priv->gpio_pushpull = le16_to_cpu(config.reset_state.gpio_mode_pb1);
1746 	gpio_latch = le16_to_cpu(config.reset_state.gpio_latch_pb1);
1747 
1748 	/*
1749 	 * Mark all pins which are not in GPIO mode.
1750 	 *
1751 	 * Refer to table 9.1 "GPIO Mode alternate Functions" in the datasheet:
1752 	 * https://www.silabs.com/documents/public/data-sheets/cp2108-datasheet.pdf
1753 	 *
1754 	 * Alternate functions of GPIO0 to GPIO3 are determine by enhancedfxn_ifc[0]
1755 	 * and the similarly for the other pins; enhancedfxn_ifc[1]: GPIO4 to GPIO7,
1756 	 * enhancedfxn_ifc[2]: GPIO8 to GPIO11, enhancedfxn_ifc[3]: GPIO12 to GPIO15.
1757 	 */
1758 	for (i = 0; i < 4; i++) {
1759 		if (config.enhancedfxn_ifc[i] & CP2108_EF_IFC_GPIO_TXLED)
1760 			priv->gpio_altfunc |= BIT(i * 4);
1761 		if (config.enhancedfxn_ifc[i] & CP2108_EF_IFC_GPIO_RXLED)
1762 			priv->gpio_altfunc |= BIT((i * 4) + 1);
1763 		if (config.enhancedfxn_ifc[i] & CP2108_EF_IFC_GPIO_RS485)
1764 			priv->gpio_altfunc |= BIT((i * 4) + 2);
1765 		if (config.enhancedfxn_ifc[i] & CP2108_EF_IFC_GPIO_CLOCK)
1766 			priv->gpio_altfunc |= BIT((i * 4) + 3);
1767 	}
1768 
1769 	/*
1770 	 * Like CP2102N, CP2108 has also no strict input and output pin
1771 	 * modes. Do the same input mode emulation as CP2102N.
1772 	 */
1773 	for (i = 0; i < priv->gc.ngpio; ++i) {
1774 		/*
1775 		 * Set direction to "input" iff pin is open-drain and reset
1776 		 * value is 1.
1777 		 */
1778 		if (!(priv->gpio_pushpull & BIT(i)) && (gpio_latch & BIT(i)))
1779 			priv->gpio_input |= BIT(i);
1780 	}
1781 
1782 	return 0;
1783 }
1784 
1785 static int cp2102n_gpioconf_init(struct usb_serial *serial)
1786 {
1787 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1788 	const u16 config_size = 0x02a6;
1789 	u8 gpio_rst_latch;
1790 	u8 config_version;
1791 	u8 gpio_pushpull;
1792 	u8 *config_buf;
1793 	u8 gpio_latch;
1794 	u8 gpio_ctrl;
1795 	int result;
1796 	u8 i;
1797 
1798 	/*
1799 	 * Retrieve device configuration from the device.
1800 	 * The array received contains all customization settings done at the
1801 	 * factory/manufacturer. Format of the array is documented at the
1802 	 * time of writing at:
1803 	 * https://www.silabs.com/community/interface/knowledge-base.entry.html/2017/03/31/cp2102n_setconfig-xsfa
1804 	 */
1805 	config_buf = kmalloc(config_size, GFP_KERNEL);
1806 	if (!config_buf)
1807 		return -ENOMEM;
1808 
1809 	result = cp210x_read_vendor_block(serial,
1810 					  REQTYPE_DEVICE_TO_HOST,
1811 					  CP210X_READ_2NCONFIG,
1812 					  config_buf,
1813 					  config_size);
1814 	if (result < 0) {
1815 		kfree(config_buf);
1816 		return result;
1817 	}
1818 
1819 	config_version = config_buf[CP210X_2NCONFIG_CONFIG_VERSION_IDX];
1820 	gpio_pushpull = config_buf[CP210X_2NCONFIG_GPIO_MODE_IDX];
1821 	gpio_ctrl = config_buf[CP210X_2NCONFIG_GPIO_CONTROL_IDX];
1822 	gpio_rst_latch = config_buf[CP210X_2NCONFIG_GPIO_RSTLATCH_IDX];
1823 
1824 	kfree(config_buf);
1825 
1826 	/* Make sure this is a config format we understand. */
1827 	if (config_version != 0x01)
1828 		return -ENOTSUPP;
1829 
1830 	priv->gc.ngpio = 4;
1831 
1832 	/*
1833 	 * Get default pin states after reset. Needed so we can determine
1834 	 * the direction of an open-drain pin.
1835 	 */
1836 	gpio_latch = (gpio_rst_latch >> 3) & 0x0f;
1837 
1838 	/* 0 indicates open-drain mode, 1 is push-pull */
1839 	priv->gpio_pushpull = (gpio_pushpull >> 3) & 0x0f;
1840 
1841 	/* 0 indicates GPIO mode, 1 is alternate function */
1842 	if (priv->partnum == CP210X_PARTNUM_CP2102N_QFN20) {
1843 		/* QFN20 is special... */
1844 		if (gpio_ctrl & CP2102N_QFN20_GPIO0_CLK_MODE)   /* GPIO 0 */
1845 			priv->gpio_altfunc |= BIT(0);
1846 		if (gpio_ctrl & CP2102N_QFN20_GPIO1_RS485_MODE) /* GPIO 1 */
1847 			priv->gpio_altfunc |= BIT(1);
1848 		if (gpio_ctrl & CP2102N_QFN20_GPIO2_TXLED_MODE) /* GPIO 2 */
1849 			priv->gpio_altfunc |= BIT(2);
1850 		if (gpio_ctrl & CP2102N_QFN20_GPIO3_RXLED_MODE) /* GPIO 3 */
1851 			priv->gpio_altfunc |= BIT(3);
1852 	} else {
1853 		priv->gpio_altfunc = (gpio_ctrl >> 2) & 0x0f;
1854 	}
1855 
1856 	if (priv->partnum == CP210X_PARTNUM_CP2102N_QFN28) {
1857 		/*
1858 		 * For the QFN28 package, GPIO4-6 are controlled by
1859 		 * the low three bits of the mode/latch fields.
1860 		 * Contrary to the document linked above, the bits for
1861 		 * the SUSPEND pins are elsewhere.  No alternate
1862 		 * function is available for these pins.
1863 		 */
1864 		priv->gc.ngpio = 7;
1865 		gpio_latch |= (gpio_rst_latch & 7) << 4;
1866 		priv->gpio_pushpull |= (gpio_pushpull & 7) << 4;
1867 	}
1868 
1869 	/*
1870 	 * The CP2102N does not strictly has input and output pin modes,
1871 	 * it only knows open-drain and push-pull modes which is set at
1872 	 * factory. An open-drain pin can function both as an
1873 	 * input or an output. We emulate input mode for open-drain pins
1874 	 * by making sure they are not driven low, and we do not allow
1875 	 * push-pull pins to be set as an input.
1876 	 */
1877 	for (i = 0; i < priv->gc.ngpio; ++i) {
1878 		/*
1879 		 * Set direction to "input" iff pin is open-drain and reset
1880 		 * value is 1.
1881 		 */
1882 		if (!(priv->gpio_pushpull & BIT(i)) && (gpio_latch & BIT(i)))
1883 			priv->gpio_input |= BIT(i);
1884 	}
1885 
1886 	return 0;
1887 }
1888 
1889 static int cp210x_gpio_init(struct usb_serial *serial)
1890 {
1891 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1892 	int result;
1893 
1894 	switch (priv->partnum) {
1895 	case CP210X_PARTNUM_CP2104:
1896 		result = cp2104_gpioconf_init(serial);
1897 		break;
1898 	case CP210X_PARTNUM_CP2105:
1899 		result = cp2105_gpioconf_init(serial);
1900 		break;
1901 	case CP210X_PARTNUM_CP2108:
1902 		/*
1903 		 * The GPIOs are not tied to any specific port so only register
1904 		 * once for interface 0.
1905 		 */
1906 		if (cp210x_interface_num(serial) != 0)
1907 			return 0;
1908 		result = cp2108_gpio_init(serial);
1909 		break;
1910 	case CP210X_PARTNUM_CP2102N_QFN28:
1911 	case CP210X_PARTNUM_CP2102N_QFN24:
1912 	case CP210X_PARTNUM_CP2102N_QFN20:
1913 		result = cp2102n_gpioconf_init(serial);
1914 		break;
1915 	default:
1916 		return 0;
1917 	}
1918 
1919 	if (result < 0)
1920 		return result;
1921 
1922 	priv->gc.label = "cp210x";
1923 	priv->gc.get_direction = cp210x_gpio_direction_get;
1924 	priv->gc.direction_input = cp210x_gpio_direction_input;
1925 	priv->gc.direction_output = cp210x_gpio_direction_output;
1926 	priv->gc.get = cp210x_gpio_get;
1927 	priv->gc.set = cp210x_gpio_set;
1928 	priv->gc.set_config = cp210x_gpio_set_config;
1929 	priv->gc.init_valid_mask = cp210x_gpio_init_valid_mask;
1930 	priv->gc.owner = THIS_MODULE;
1931 	priv->gc.parent = &serial->interface->dev;
1932 	priv->gc.base = -1;
1933 	priv->gc.can_sleep = true;
1934 
1935 	result = gpiochip_add_data(&priv->gc, serial);
1936 	if (!result)
1937 		priv->gpio_registered = true;
1938 
1939 	return result;
1940 }
1941 
1942 static void cp210x_gpio_remove(struct usb_serial *serial)
1943 {
1944 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1945 
1946 	if (priv->gpio_registered) {
1947 		gpiochip_remove(&priv->gc);
1948 		priv->gpio_registered = false;
1949 	}
1950 }
1951 
1952 #else
1953 
1954 static int cp210x_gpio_init(struct usb_serial *serial)
1955 {
1956 	return 0;
1957 }
1958 
1959 static void cp210x_gpio_remove(struct usb_serial *serial)
1960 {
1961 	/* Nothing to do */
1962 }
1963 
1964 #endif
1965 
1966 static int cp210x_port_probe(struct usb_serial_port *port)
1967 {
1968 	struct usb_serial *serial = port->serial;
1969 	struct cp210x_port_private *port_priv;
1970 
1971 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
1972 	if (!port_priv)
1973 		return -ENOMEM;
1974 
1975 	port_priv->bInterfaceNumber = cp210x_interface_num(serial);
1976 	mutex_init(&port_priv->mutex);
1977 
1978 	usb_set_serial_port_data(port, port_priv);
1979 
1980 	return 0;
1981 }
1982 
1983 static void cp210x_port_remove(struct usb_serial_port *port)
1984 {
1985 	struct cp210x_port_private *port_priv;
1986 
1987 	port_priv = usb_get_serial_port_data(port);
1988 	kfree(port_priv);
1989 }
1990 
1991 static void cp210x_init_max_speed(struct usb_serial *serial)
1992 {
1993 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1994 	bool use_actual_rate = false;
1995 	speed_t min = 300;
1996 	speed_t max;
1997 
1998 	switch (priv->partnum) {
1999 	case CP210X_PARTNUM_CP2101:
2000 		max = 921600;
2001 		break;
2002 	case CP210X_PARTNUM_CP2102:
2003 	case CP210X_PARTNUM_CP2103:
2004 		max = 1000000;
2005 		break;
2006 	case CP210X_PARTNUM_CP2104:
2007 		use_actual_rate = true;
2008 		max = 2000000;
2009 		break;
2010 	case CP210X_PARTNUM_CP2108:
2011 		max = 2000000;
2012 		break;
2013 	case CP210X_PARTNUM_CP2105:
2014 		if (cp210x_interface_num(serial) == 0) {
2015 			use_actual_rate = true;
2016 			max = 2000000;	/* ECI */
2017 		} else {
2018 			min = 2400;
2019 			max = 921600;	/* SCI */
2020 		}
2021 		break;
2022 	case CP210X_PARTNUM_CP2102N_QFN28:
2023 	case CP210X_PARTNUM_CP2102N_QFN24:
2024 	case CP210X_PARTNUM_CP2102N_QFN20:
2025 		use_actual_rate = true;
2026 		max = 3000000;
2027 		break;
2028 	default:
2029 		max = 2000000;
2030 		break;
2031 	}
2032 
2033 	priv->min_speed = min;
2034 	priv->max_speed = max;
2035 	priv->use_actual_rate = use_actual_rate;
2036 }
2037 
2038 static void cp2102_determine_quirks(struct usb_serial *serial)
2039 {
2040 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
2041 	u8 *buf;
2042 	int ret;
2043 
2044 	buf = kmalloc(2, GFP_KERNEL);
2045 	if (!buf)
2046 		return;
2047 	/*
2048 	 * Some (possibly counterfeit) CP2102 do not support event-insertion
2049 	 * mode and respond differently to malformed vendor requests.
2050 	 * Specifically, they return one instead of two bytes when sent a
2051 	 * two-byte part-number request.
2052 	 */
2053 	ret = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
2054 			CP210X_VENDOR_SPECIFIC, REQTYPE_DEVICE_TO_HOST,
2055 			CP210X_GET_PARTNUM, 0, buf, 2, USB_CTRL_GET_TIMEOUT);
2056 	if (ret == 1) {
2057 		dev_dbg(&serial->interface->dev,
2058 				"device does not support event-insertion mode\n");
2059 		priv->no_event_mode = true;
2060 	}
2061 
2062 	kfree(buf);
2063 }
2064 
2065 static int cp210x_get_fw_version(struct usb_serial *serial, u16 value)
2066 {
2067 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
2068 	u8 ver[3];
2069 	int ret;
2070 
2071 	ret = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST, value,
2072 			ver, sizeof(ver));
2073 	if (ret)
2074 		return ret;
2075 
2076 	dev_dbg(&serial->interface->dev, "%s - %d.%d.%d\n", __func__,
2077 			ver[0], ver[1], ver[2]);
2078 
2079 	priv->fw_version = ver[0] << 16 | ver[1] << 8 | ver[2];
2080 
2081 	return 0;
2082 }
2083 
2084 static void cp210x_determine_type(struct usb_serial *serial)
2085 {
2086 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
2087 	int ret;
2088 
2089 	ret = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
2090 			CP210X_GET_PARTNUM, &priv->partnum,
2091 			sizeof(priv->partnum));
2092 	if (ret < 0) {
2093 		dev_warn(&serial->interface->dev,
2094 				"querying part number failed\n");
2095 		priv->partnum = CP210X_PARTNUM_UNKNOWN;
2096 		return;
2097 	}
2098 
2099 	dev_dbg(&serial->interface->dev, "partnum = 0x%02x\n", priv->partnum);
2100 
2101 	switch (priv->partnum) {
2102 	case CP210X_PARTNUM_CP2102:
2103 		cp2102_determine_quirks(serial);
2104 		break;
2105 	case CP210X_PARTNUM_CP2105:
2106 	case CP210X_PARTNUM_CP2108:
2107 		cp210x_get_fw_version(serial, CP210X_GET_FW_VER);
2108 		break;
2109 	case CP210X_PARTNUM_CP2102N_QFN28:
2110 	case CP210X_PARTNUM_CP2102N_QFN24:
2111 	case CP210X_PARTNUM_CP2102N_QFN20:
2112 		ret = cp210x_get_fw_version(serial, CP210X_GET_FW_VER_2N);
2113 		if (ret)
2114 			break;
2115 		if (priv->fw_version <= 0x10004)
2116 			priv->no_flow_control = true;
2117 		break;
2118 	default:
2119 		break;
2120 	}
2121 }
2122 
2123 static int cp210x_attach(struct usb_serial *serial)
2124 {
2125 	int result;
2126 	struct cp210x_serial_private *priv;
2127 
2128 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
2129 	if (!priv)
2130 		return -ENOMEM;
2131 
2132 	usb_set_serial_data(serial, priv);
2133 
2134 	cp210x_determine_type(serial);
2135 	cp210x_init_max_speed(serial);
2136 
2137 	result = cp210x_gpio_init(serial);
2138 	if (result < 0) {
2139 		dev_err(&serial->interface->dev, "GPIO initialisation failed: %d\n",
2140 				result);
2141 	}
2142 
2143 	return 0;
2144 }
2145 
2146 static void cp210x_disconnect(struct usb_serial *serial)
2147 {
2148 	cp210x_gpio_remove(serial);
2149 }
2150 
2151 static void cp210x_release(struct usb_serial *serial)
2152 {
2153 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
2154 
2155 	cp210x_gpio_remove(serial);
2156 
2157 	kfree(priv);
2158 }
2159 
2160 module_usb_serial_driver(serial_drivers, id_table);
2161 
2162 MODULE_DESCRIPTION(DRIVER_DESC);
2163 MODULE_LICENSE("GPL v2");
2164