xref: /linux/drivers/usb/serial/cp210x.c (revision 367b160fe4717c14a2a978b6f9ffb75a7762d3ed)
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  *
7  * Support to set flow control line levels using TIOCMGET and TIOCMSET
8  * thanks to Karl Hiramoto karl@hiramoto.org. RTSCTS hardware flow
9  * control thanks to Munir Nassar nassarmu@real-time.com
10  *
11  */
12 
13 #include <linux/kernel.h>
14 #include <linux/errno.h>
15 #include <linux/slab.h>
16 #include <linux/tty.h>
17 #include <linux/tty_flip.h>
18 #include <linux/module.h>
19 #include <linux/moduleparam.h>
20 #include <linux/usb.h>
21 #include <linux/uaccess.h>
22 #include <linux/usb/serial.h>
23 #include <linux/gpio/driver.h>
24 #include <linux/bitops.h>
25 #include <linux/mutex.h>
26 
27 #define DRIVER_DESC "Silicon Labs CP210x RS232 serial adaptor driver"
28 
29 /*
30  * Function Prototypes
31  */
32 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *);
33 static void cp210x_close(struct usb_serial_port *);
34 static void cp210x_get_termios(struct tty_struct *, struct usb_serial_port *);
35 static void cp210x_get_termios_port(struct usb_serial_port *port,
36 	tcflag_t *cflagp, unsigned int *baudp);
37 static void cp210x_change_speed(struct tty_struct *, struct usb_serial_port *,
38 							struct ktermios *);
39 static void cp210x_set_termios(struct tty_struct *, struct usb_serial_port *,
40 							struct ktermios*);
41 static bool cp210x_tx_empty(struct usb_serial_port *port);
42 static int cp210x_tiocmget(struct tty_struct *);
43 static int cp210x_tiocmset(struct tty_struct *, unsigned int, unsigned int);
44 static int cp210x_tiocmset_port(struct usb_serial_port *port,
45 		unsigned int, unsigned int);
46 static void cp210x_break_ctl(struct tty_struct *, int);
47 static int cp210x_attach(struct usb_serial *);
48 static void cp210x_disconnect(struct usb_serial *);
49 static void cp210x_release(struct usb_serial *);
50 static int cp210x_port_probe(struct usb_serial_port *);
51 static int cp210x_port_remove(struct usb_serial_port *);
52 static void cp210x_dtr_rts(struct usb_serial_port *p, int on);
53 
54 static const struct usb_device_id id_table[] = {
55 	{ USB_DEVICE(0x045B, 0x0053) }, /* Renesas RX610 RX-Stick */
56 	{ USB_DEVICE(0x0471, 0x066A) }, /* AKTAKOM ACE-1001 cable */
57 	{ USB_DEVICE(0x0489, 0xE000) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
58 	{ USB_DEVICE(0x0489, 0xE003) }, /* Pirelli Broadband S.p.A, DP-L10 SIP/GSM Mobile */
59 	{ USB_DEVICE(0x0745, 0x1000) }, /* CipherLab USB CCD Barcode Scanner 1000 */
60 	{ USB_DEVICE(0x0846, 0x1100) }, /* NetGear Managed Switch M4100 series, M5300 series, M7100 series */
61 	{ USB_DEVICE(0x08e6, 0x5501) }, /* Gemalto Prox-PU/CU contactless smartcard reader */
62 	{ USB_DEVICE(0x08FD, 0x000A) }, /* Digianswer A/S , ZigBee/802.15.4 MAC Device */
63 	{ USB_DEVICE(0x0908, 0x01FF) }, /* Siemens RUGGEDCOM USB Serial Console */
64 	{ USB_DEVICE(0x0BED, 0x1100) }, /* MEI (TM) Cashflow-SC Bill/Voucher Acceptor */
65 	{ USB_DEVICE(0x0BED, 0x1101) }, /* MEI series 2000 Combo Acceptor */
66 	{ USB_DEVICE(0x0FCF, 0x1003) }, /* Dynastream ANT development board */
67 	{ USB_DEVICE(0x0FCF, 0x1004) }, /* Dynastream ANT2USB */
68 	{ USB_DEVICE(0x0FCF, 0x1006) }, /* Dynastream ANT development board */
69 	{ USB_DEVICE(0x0FDE, 0xCA05) }, /* OWL Wireless Electricity Monitor CM-160 */
70 	{ USB_DEVICE(0x10A6, 0xAA26) }, /* Knock-off DCU-11 cable */
71 	{ USB_DEVICE(0x10AB, 0x10C5) }, /* Siemens MC60 Cable */
72 	{ USB_DEVICE(0x10B5, 0xAC70) }, /* Nokia CA-42 USB */
73 	{ USB_DEVICE(0x10C4, 0x0F91) }, /* Vstabi */
74 	{ USB_DEVICE(0x10C4, 0x1101) }, /* Arkham Technology DS101 Bus Monitor */
75 	{ USB_DEVICE(0x10C4, 0x1601) }, /* Arkham Technology DS101 Adapter */
76 	{ USB_DEVICE(0x10C4, 0x800A) }, /* SPORTident BSM7-D-USB main station */
77 	{ USB_DEVICE(0x10C4, 0x803B) }, /* Pololu USB-serial converter */
78 	{ USB_DEVICE(0x10C4, 0x8044) }, /* Cygnal Debug Adapter */
79 	{ USB_DEVICE(0x10C4, 0x804E) }, /* Software Bisque Paramount ME build-in converter */
80 	{ USB_DEVICE(0x10C4, 0x8053) }, /* Enfora EDG1228 */
81 	{ USB_DEVICE(0x10C4, 0x8054) }, /* Enfora GSM2228 */
82 	{ USB_DEVICE(0x10C4, 0x8066) }, /* Argussoft In-System Programmer */
83 	{ USB_DEVICE(0x10C4, 0x806F) }, /* IMS USB to RS422 Converter Cable */
84 	{ USB_DEVICE(0x10C4, 0x807A) }, /* Crumb128 board */
85 	{ USB_DEVICE(0x10C4, 0x80C4) }, /* Cygnal Integrated Products, Inc., Optris infrared thermometer */
86 	{ USB_DEVICE(0x10C4, 0x80CA) }, /* Degree Controls Inc */
87 	{ USB_DEVICE(0x10C4, 0x80DD) }, /* Tracient RFID */
88 	{ USB_DEVICE(0x10C4, 0x80F6) }, /* Suunto sports instrument */
89 	{ USB_DEVICE(0x10C4, 0x8115) }, /* Arygon NFC/Mifare Reader */
90 	{ USB_DEVICE(0x10C4, 0x813D) }, /* Burnside Telecom Deskmobile */
91 	{ USB_DEVICE(0x10C4, 0x813F) }, /* Tams Master Easy Control */
92 	{ USB_DEVICE(0x10C4, 0x814A) }, /* West Mountain Radio RIGblaster P&P */
93 	{ USB_DEVICE(0x10C4, 0x814B) }, /* West Mountain Radio RIGtalk */
94 	{ USB_DEVICE(0x2405, 0x0003) }, /* West Mountain Radio RIGblaster Advantage */
95 	{ USB_DEVICE(0x10C4, 0x8156) }, /* B&G H3000 link cable */
96 	{ USB_DEVICE(0x10C4, 0x815E) }, /* Helicomm IP-Link 1220-DVM */
97 	{ USB_DEVICE(0x10C4, 0x815F) }, /* Timewave HamLinkUSB */
98 	{ USB_DEVICE(0x10C4, 0x817C) }, /* CESINEL MEDCAL N Power Quality Monitor */
99 	{ USB_DEVICE(0x10C4, 0x817D) }, /* CESINEL MEDCAL NT Power Quality Monitor */
100 	{ USB_DEVICE(0x10C4, 0x817E) }, /* CESINEL MEDCAL S Power Quality Monitor */
101 	{ USB_DEVICE(0x10C4, 0x818B) }, /* AVIT Research USB to TTL */
102 	{ USB_DEVICE(0x10C4, 0x819F) }, /* MJS USB Toslink Switcher */
103 	{ USB_DEVICE(0x10C4, 0x81A6) }, /* ThinkOptics WavIt */
104 	{ USB_DEVICE(0x10C4, 0x81A9) }, /* Multiplex RC Interface */
105 	{ USB_DEVICE(0x10C4, 0x81AC) }, /* MSD Dash Hawk */
106 	{ USB_DEVICE(0x10C4, 0x81AD) }, /* INSYS USB Modem */
107 	{ USB_DEVICE(0x10C4, 0x81C8) }, /* Lipowsky Industrie Elektronik GmbH, Baby-JTAG */
108 	{ USB_DEVICE(0x10C4, 0x81D7) }, /* IAI Corp. RCB-CV-USB USB to RS485 Adaptor */
109 	{ USB_DEVICE(0x10C4, 0x81E2) }, /* Lipowsky Industrie Elektronik GmbH, Baby-LIN */
110 	{ USB_DEVICE(0x10C4, 0x81E7) }, /* Aerocomm Radio */
111 	{ USB_DEVICE(0x10C4, 0x81E8) }, /* Zephyr Bioharness */
112 	{ USB_DEVICE(0x10C4, 0x81F2) }, /* C1007 HF band RFID controller */
113 	{ USB_DEVICE(0x10C4, 0x8218) }, /* Lipowsky Industrie Elektronik GmbH, HARP-1 */
114 	{ USB_DEVICE(0x10C4, 0x822B) }, /* Modem EDGE(GSM) Comander 2 */
115 	{ USB_DEVICE(0x10C4, 0x826B) }, /* Cygnal Integrated Products, Inc., Fasttrax GPS demonstration module */
116 	{ USB_DEVICE(0x10C4, 0x8281) }, /* Nanotec Plug & Drive */
117 	{ USB_DEVICE(0x10C4, 0x8293) }, /* Telegesis ETRX2USB */
118 	{ USB_DEVICE(0x10C4, 0x82EF) }, /* CESINEL FALCO 6105 AC Power Supply */
119 	{ USB_DEVICE(0x10C4, 0x82F1) }, /* CESINEL MEDCAL EFD Earth Fault Detector */
120 	{ USB_DEVICE(0x10C4, 0x82F2) }, /* CESINEL MEDCAL ST Network Analyzer */
121 	{ USB_DEVICE(0x10C4, 0x82F4) }, /* Starizona MicroTouch */
122 	{ USB_DEVICE(0x10C4, 0x82F9) }, /* Procyon AVS */
123 	{ USB_DEVICE(0x10C4, 0x8341) }, /* Siemens MC35PU GPRS Modem */
124 	{ USB_DEVICE(0x10C4, 0x8382) }, /* Cygnal Integrated Products, Inc. */
125 	{ USB_DEVICE(0x10C4, 0x83A8) }, /* Amber Wireless AMB2560 */
126 	{ USB_DEVICE(0x10C4, 0x83D8) }, /* DekTec DTA Plus VHF/UHF Booster/Attenuator */
127 	{ USB_DEVICE(0x10C4, 0x8411) }, /* Kyocera GPS Module */
128 	{ USB_DEVICE(0x10C4, 0x8418) }, /* IRZ Automation Teleport SG-10 GSM/GPRS Modem */
129 	{ USB_DEVICE(0x10C4, 0x846E) }, /* BEI USB Sensor Interface (VCP) */
130 	{ USB_DEVICE(0x10C4, 0x8470) }, /* Juniper Networks BX Series System Console */
131 	{ USB_DEVICE(0x10C4, 0x8477) }, /* Balluff RFID */
132 	{ USB_DEVICE(0x10C4, 0x84B6) }, /* Starizona Hyperion */
133 	{ USB_DEVICE(0x10C4, 0x851E) }, /* CESINEL MEDCAL PT Network Analyzer */
134 	{ USB_DEVICE(0x10C4, 0x85A7) }, /* LifeScan OneTouch Verio IQ */
135 	{ USB_DEVICE(0x10C4, 0x85B8) }, /* CESINEL ReCon T Energy Logger */
136 	{ USB_DEVICE(0x10C4, 0x85EA) }, /* AC-Services IBUS-IF */
137 	{ USB_DEVICE(0x10C4, 0x85EB) }, /* AC-Services CIS-IBUS */
138 	{ USB_DEVICE(0x10C4, 0x85F8) }, /* Virtenio Preon32 */
139 	{ USB_DEVICE(0x10C4, 0x8664) }, /* AC-Services CAN-IF */
140 	{ USB_DEVICE(0x10C4, 0x8665) }, /* AC-Services OBD-IF */
141 	{ USB_DEVICE(0x10C4, 0x8856) },	/* CEL EM357 ZigBee USB Stick - LR */
142 	{ USB_DEVICE(0x10C4, 0x8857) },	/* CEL EM357 ZigBee USB Stick */
143 	{ USB_DEVICE(0x10C4, 0x88A4) }, /* MMB Networks ZigBee USB Device */
144 	{ USB_DEVICE(0x10C4, 0x88A5) }, /* Planet Innovation Ingeni ZigBee USB Device */
145 	{ USB_DEVICE(0x10C4, 0x88FB) }, /* CESINEL MEDCAL STII Network Analyzer */
146 	{ USB_DEVICE(0x10C4, 0x8938) }, /* CESINEL MEDCAL S II Network Analyzer */
147 	{ USB_DEVICE(0x10C4, 0x8946) }, /* Ketra N1 Wireless Interface */
148 	{ USB_DEVICE(0x10C4, 0x8962) }, /* Brim Brothers charging dock */
149 	{ USB_DEVICE(0x10C4, 0x8977) },	/* CEL MeshWorks DevKit Device */
150 	{ USB_DEVICE(0x10C4, 0x8998) }, /* KCF Technologies PRN */
151 	{ USB_DEVICE(0x10C4, 0x89A4) }, /* CESINEL FTBC Flexible Thyristor Bridge Controller */
152 	{ USB_DEVICE(0x10C4, 0x89FB) }, /* Qivicon ZigBee USB Radio Stick */
153 	{ USB_DEVICE(0x10C4, 0x8A2A) }, /* HubZ dual ZigBee and Z-Wave dongle */
154 	{ USB_DEVICE(0x10C4, 0x8A5E) }, /* CEL EM3588 ZigBee USB Stick Long Range */
155 	{ USB_DEVICE(0x10C4, 0x8B34) }, /* Qivicon ZigBee USB Radio Stick */
156 	{ USB_DEVICE(0x10C4, 0xEA60) }, /* Silicon Labs factory default */
157 	{ USB_DEVICE(0x10C4, 0xEA61) }, /* Silicon Labs factory default */
158 	{ USB_DEVICE(0x10C4, 0xEA63) }, /* Silicon Labs Windows Update (CP2101-4/CP2102N) */
159 	{ USB_DEVICE(0x10C4, 0xEA70) }, /* Silicon Labs factory default */
160 	{ USB_DEVICE(0x10C4, 0xEA71) }, /* Infinity GPS-MIC-1 Radio Monophone */
161 	{ USB_DEVICE(0x10C4, 0xEA7A) }, /* Silicon Labs Windows Update (CP2105) */
162 	{ USB_DEVICE(0x10C4, 0xEA7B) }, /* Silicon Labs Windows Update (CP2108) */
163 	{ USB_DEVICE(0x10C4, 0xF001) }, /* Elan Digital Systems USBscope50 */
164 	{ USB_DEVICE(0x10C4, 0xF002) }, /* Elan Digital Systems USBwave12 */
165 	{ USB_DEVICE(0x10C4, 0xF003) }, /* Elan Digital Systems USBpulse100 */
166 	{ USB_DEVICE(0x10C4, 0xF004) }, /* Elan Digital Systems USBcount50 */
167 	{ USB_DEVICE(0x10C5, 0xEA61) }, /* Silicon Labs MobiData GPRS USB Modem */
168 	{ USB_DEVICE(0x10CE, 0xEA6A) }, /* Silicon Labs MobiData GPRS USB Modem 100EU */
169 	{ USB_DEVICE(0x12B8, 0xEC60) }, /* Link G4 ECU */
170 	{ USB_DEVICE(0x12B8, 0xEC62) }, /* Link G4+ ECU */
171 	{ USB_DEVICE(0x13AD, 0x9999) }, /* Baltech card reader */
172 	{ USB_DEVICE(0x1555, 0x0004) }, /* Owen AC4 USB-RS485 Converter */
173 	{ USB_DEVICE(0x155A, 0x1006) },	/* ELDAT Easywave RX09 */
174 	{ USB_DEVICE(0x166A, 0x0201) }, /* Clipsal 5500PACA C-Bus Pascal Automation Controller */
175 	{ USB_DEVICE(0x166A, 0x0301) }, /* Clipsal 5800PC C-Bus Wireless PC Interface */
176 	{ USB_DEVICE(0x166A, 0x0303) }, /* Clipsal 5500PCU C-Bus USB interface */
177 	{ USB_DEVICE(0x166A, 0x0304) }, /* Clipsal 5000CT2 C-Bus Black and White Touchscreen */
178 	{ USB_DEVICE(0x166A, 0x0305) }, /* Clipsal C-5000CT2 C-Bus Spectrum Colour Touchscreen */
179 	{ USB_DEVICE(0x166A, 0x0401) }, /* Clipsal L51xx C-Bus Architectural Dimmer */
180 	{ USB_DEVICE(0x166A, 0x0101) }, /* Clipsal 5560884 C-Bus Multi-room Audio Matrix Switcher */
181 	{ USB_DEVICE(0x16C0, 0x09B0) }, /* Lunatico Seletek */
182 	{ USB_DEVICE(0x16C0, 0x09B1) }, /* Lunatico Seletek */
183 	{ USB_DEVICE(0x16D6, 0x0001) }, /* Jablotron serial interface */
184 	{ USB_DEVICE(0x16DC, 0x0010) }, /* W-IE-NE-R Plein & Baus GmbH PL512 Power Supply */
185 	{ USB_DEVICE(0x16DC, 0x0011) }, /* W-IE-NE-R Plein & Baus GmbH RCM Remote Control for MARATON Power Supply */
186 	{ USB_DEVICE(0x16DC, 0x0012) }, /* W-IE-NE-R Plein & Baus GmbH MPOD Multi Channel Power Supply */
187 	{ USB_DEVICE(0x16DC, 0x0015) }, /* W-IE-NE-R Plein & Baus GmbH CML Control, Monitoring and Data Logger */
188 	{ USB_DEVICE(0x17A8, 0x0001) }, /* Kamstrup Optical Eye/3-wire */
189 	{ USB_DEVICE(0x17A8, 0x0005) }, /* Kamstrup M-Bus Master MultiPort 250D */
190 	{ USB_DEVICE(0x17F4, 0xAAAA) }, /* Wavesense Jazz blood glucose meter */
191 	{ USB_DEVICE(0x1843, 0x0200) }, /* Vaisala USB Instrument Cable */
192 	{ USB_DEVICE(0x18EF, 0xE00F) }, /* ELV USB-I2C-Interface */
193 	{ USB_DEVICE(0x18EF, 0xE025) }, /* ELV Marble Sound Board 1 */
194 	{ USB_DEVICE(0x18EF, 0xE030) }, /* ELV ALC 8xxx Battery Charger */
195 	{ USB_DEVICE(0x18EF, 0xE032) }, /* ELV TFD500 Data Logger */
196 	{ USB_DEVICE(0x1901, 0x0190) }, /* GE B850 CP2105 Recorder interface */
197 	{ USB_DEVICE(0x1901, 0x0193) }, /* GE B650 CP2104 PMC interface */
198 	{ USB_DEVICE(0x1901, 0x0194) },	/* GE Healthcare Remote Alarm Box */
199 	{ USB_DEVICE(0x1901, 0x0195) },	/* GE B850/B650/B450 CP2104 DP UART interface */
200 	{ USB_DEVICE(0x1901, 0x0196) },	/* GE B850 CP2105 DP UART interface */
201 	{ USB_DEVICE(0x19CF, 0x3000) }, /* Parrot NMEA GPS Flight Recorder */
202 	{ USB_DEVICE(0x1ADB, 0x0001) }, /* Schweitzer Engineering C662 Cable */
203 	{ USB_DEVICE(0x1B1C, 0x1C00) }, /* Corsair USB Dongle */
204 	{ USB_DEVICE(0x1BA4, 0x0002) },	/* Silicon Labs 358x factory default */
205 	{ USB_DEVICE(0x1BE3, 0x07A6) }, /* WAGO 750-923 USB Service Cable */
206 	{ USB_DEVICE(0x1D6F, 0x0010) }, /* Seluxit ApS RF Dongle */
207 	{ USB_DEVICE(0x1E29, 0x0102) }, /* Festo CPX-USB */
208 	{ USB_DEVICE(0x1E29, 0x0501) }, /* Festo CMSP */
209 	{ USB_DEVICE(0x1FB9, 0x0100) }, /* Lake Shore Model 121 Current Source */
210 	{ USB_DEVICE(0x1FB9, 0x0200) }, /* Lake Shore Model 218A Temperature Monitor */
211 	{ USB_DEVICE(0x1FB9, 0x0201) }, /* Lake Shore Model 219 Temperature Monitor */
212 	{ USB_DEVICE(0x1FB9, 0x0202) }, /* Lake Shore Model 233 Temperature Transmitter */
213 	{ USB_DEVICE(0x1FB9, 0x0203) }, /* Lake Shore Model 235 Temperature Transmitter */
214 	{ USB_DEVICE(0x1FB9, 0x0300) }, /* Lake Shore Model 335 Temperature Controller */
215 	{ USB_DEVICE(0x1FB9, 0x0301) }, /* Lake Shore Model 336 Temperature Controller */
216 	{ USB_DEVICE(0x1FB9, 0x0302) }, /* Lake Shore Model 350 Temperature Controller */
217 	{ USB_DEVICE(0x1FB9, 0x0303) }, /* Lake Shore Model 371 AC Bridge */
218 	{ USB_DEVICE(0x1FB9, 0x0400) }, /* Lake Shore Model 411 Handheld Gaussmeter */
219 	{ USB_DEVICE(0x1FB9, 0x0401) }, /* Lake Shore Model 425 Gaussmeter */
220 	{ USB_DEVICE(0x1FB9, 0x0402) }, /* Lake Shore Model 455A Gaussmeter */
221 	{ USB_DEVICE(0x1FB9, 0x0403) }, /* Lake Shore Model 475A Gaussmeter */
222 	{ USB_DEVICE(0x1FB9, 0x0404) }, /* Lake Shore Model 465 Three Axis Gaussmeter */
223 	{ USB_DEVICE(0x1FB9, 0x0600) }, /* Lake Shore Model 625A Superconducting MPS */
224 	{ USB_DEVICE(0x1FB9, 0x0601) }, /* Lake Shore Model 642A Magnet Power Supply */
225 	{ USB_DEVICE(0x1FB9, 0x0602) }, /* Lake Shore Model 648 Magnet Power Supply */
226 	{ USB_DEVICE(0x1FB9, 0x0700) }, /* Lake Shore Model 737 VSM Controller */
227 	{ USB_DEVICE(0x1FB9, 0x0701) }, /* Lake Shore Model 776 Hall Matrix */
228 	{ USB_DEVICE(0x2626, 0xEA60) }, /* Aruba Networks 7xxx USB Serial Console */
229 	{ USB_DEVICE(0x3195, 0xF190) }, /* Link Instruments MSO-19 */
230 	{ USB_DEVICE(0x3195, 0xF280) }, /* Link Instruments MSO-28 */
231 	{ USB_DEVICE(0x3195, 0xF281) }, /* Link Instruments MSO-28 */
232 	{ USB_DEVICE(0x3923, 0x7A0B) }, /* National Instruments USB Serial Console */
233 	{ USB_DEVICE(0x413C, 0x9500) }, /* DW700 GPS USB interface */
234 	{ } /* Terminating Entry */
235 };
236 
237 MODULE_DEVICE_TABLE(usb, id_table);
238 
239 struct cp210x_serial_private {
240 #ifdef CONFIG_GPIOLIB
241 	struct gpio_chip	gc;
242 	u8			config;
243 	u8			gpio_mode;
244 	bool			gpio_registered;
245 #endif
246 	u8			partnum;
247 };
248 
249 struct cp210x_port_private {
250 	__u8			bInterfaceNumber;
251 	bool			has_swapped_line_ctl;
252 };
253 
254 static struct usb_serial_driver cp210x_device = {
255 	.driver = {
256 		.owner =	THIS_MODULE,
257 		.name =		"cp210x",
258 	},
259 	.id_table		= id_table,
260 	.num_ports		= 1,
261 	.bulk_in_size		= 256,
262 	.bulk_out_size		= 256,
263 	.open			= cp210x_open,
264 	.close			= cp210x_close,
265 	.break_ctl		= cp210x_break_ctl,
266 	.set_termios		= cp210x_set_termios,
267 	.tx_empty		= cp210x_tx_empty,
268 	.tiocmget		= cp210x_tiocmget,
269 	.tiocmset		= cp210x_tiocmset,
270 	.attach			= cp210x_attach,
271 	.disconnect		= cp210x_disconnect,
272 	.release		= cp210x_release,
273 	.port_probe		= cp210x_port_probe,
274 	.port_remove		= cp210x_port_remove,
275 	.dtr_rts		= cp210x_dtr_rts
276 };
277 
278 static struct usb_serial_driver * const serial_drivers[] = {
279 	&cp210x_device, NULL
280 };
281 
282 /* Config request types */
283 #define REQTYPE_HOST_TO_INTERFACE	0x41
284 #define REQTYPE_INTERFACE_TO_HOST	0xc1
285 #define REQTYPE_HOST_TO_DEVICE	0x40
286 #define REQTYPE_DEVICE_TO_HOST	0xc0
287 
288 /* Config request codes */
289 #define CP210X_IFC_ENABLE	0x00
290 #define CP210X_SET_BAUDDIV	0x01
291 #define CP210X_GET_BAUDDIV	0x02
292 #define CP210X_SET_LINE_CTL	0x03
293 #define CP210X_GET_LINE_CTL	0x04
294 #define CP210X_SET_BREAK	0x05
295 #define CP210X_IMM_CHAR		0x06
296 #define CP210X_SET_MHS		0x07
297 #define CP210X_GET_MDMSTS	0x08
298 #define CP210X_SET_XON		0x09
299 #define CP210X_SET_XOFF		0x0A
300 #define CP210X_SET_EVENTMASK	0x0B
301 #define CP210X_GET_EVENTMASK	0x0C
302 #define CP210X_SET_CHAR		0x0D
303 #define CP210X_GET_CHARS	0x0E
304 #define CP210X_GET_PROPS	0x0F
305 #define CP210X_GET_COMM_STATUS	0x10
306 #define CP210X_RESET		0x11
307 #define CP210X_PURGE		0x12
308 #define CP210X_SET_FLOW		0x13
309 #define CP210X_GET_FLOW		0x14
310 #define CP210X_EMBED_EVENTS	0x15
311 #define CP210X_GET_EVENTSTATE	0x16
312 #define CP210X_SET_CHARS	0x19
313 #define CP210X_GET_BAUDRATE	0x1D
314 #define CP210X_SET_BAUDRATE	0x1E
315 #define CP210X_VENDOR_SPECIFIC	0xFF
316 
317 /* CP210X_IFC_ENABLE */
318 #define UART_ENABLE		0x0001
319 #define UART_DISABLE		0x0000
320 
321 /* CP210X_(SET|GET)_BAUDDIV */
322 #define BAUD_RATE_GEN_FREQ	0x384000
323 
324 /* CP210X_(SET|GET)_LINE_CTL */
325 #define BITS_DATA_MASK		0X0f00
326 #define BITS_DATA_5		0X0500
327 #define BITS_DATA_6		0X0600
328 #define BITS_DATA_7		0X0700
329 #define BITS_DATA_8		0X0800
330 #define BITS_DATA_9		0X0900
331 
332 #define BITS_PARITY_MASK	0x00f0
333 #define BITS_PARITY_NONE	0x0000
334 #define BITS_PARITY_ODD		0x0010
335 #define BITS_PARITY_EVEN	0x0020
336 #define BITS_PARITY_MARK	0x0030
337 #define BITS_PARITY_SPACE	0x0040
338 
339 #define BITS_STOP_MASK		0x000f
340 #define BITS_STOP_1		0x0000
341 #define BITS_STOP_1_5		0x0001
342 #define BITS_STOP_2		0x0002
343 
344 /* CP210X_SET_BREAK */
345 #define BREAK_ON		0x0001
346 #define BREAK_OFF		0x0000
347 
348 /* CP210X_(SET_MHS|GET_MDMSTS) */
349 #define CONTROL_DTR		0x0001
350 #define CONTROL_RTS		0x0002
351 #define CONTROL_CTS		0x0010
352 #define CONTROL_DSR		0x0020
353 #define CONTROL_RING		0x0040
354 #define CONTROL_DCD		0x0080
355 #define CONTROL_WRITE_DTR	0x0100
356 #define CONTROL_WRITE_RTS	0x0200
357 
358 /* CP210X_VENDOR_SPECIFIC values */
359 #define CP210X_READ_LATCH	0x00C2
360 #define CP210X_GET_PARTNUM	0x370B
361 #define CP210X_GET_PORTCONFIG	0x370C
362 #define CP210X_GET_DEVICEMODE	0x3711
363 #define CP210X_WRITE_LATCH	0x37E1
364 
365 /* Part number definitions */
366 #define CP210X_PARTNUM_CP2101	0x01
367 #define CP210X_PARTNUM_CP2102	0x02
368 #define CP210X_PARTNUM_CP2103	0x03
369 #define CP210X_PARTNUM_CP2104	0x04
370 #define CP210X_PARTNUM_CP2105	0x05
371 #define CP210X_PARTNUM_CP2108	0x08
372 #define CP210X_PARTNUM_UNKNOWN	0xFF
373 
374 /* CP210X_GET_COMM_STATUS returns these 0x13 bytes */
375 struct cp210x_comm_status {
376 	__le32   ulErrors;
377 	__le32   ulHoldReasons;
378 	__le32   ulAmountInInQueue;
379 	__le32   ulAmountInOutQueue;
380 	u8       bEofReceived;
381 	u8       bWaitForImmediate;
382 	u8       bReserved;
383 } __packed;
384 
385 /*
386  * CP210X_PURGE - 16 bits passed in wValue of USB request.
387  * SiLabs app note AN571 gives a strange description of the 4 bits:
388  * bit 0 or bit 2 clears the transmit queue and 1 or 3 receive.
389  * writing 1 to all, however, purges cp2108 well enough to avoid the hang.
390  */
391 #define PURGE_ALL		0x000f
392 
393 /* CP210X_GET_FLOW/CP210X_SET_FLOW read/write these 0x10 bytes */
394 struct cp210x_flow_ctl {
395 	__le32	ulControlHandshake;
396 	__le32	ulFlowReplace;
397 	__le32	ulXonLimit;
398 	__le32	ulXoffLimit;
399 } __packed;
400 
401 /* cp210x_flow_ctl::ulControlHandshake */
402 #define CP210X_SERIAL_DTR_MASK		GENMASK(1, 0)
403 #define CP210X_SERIAL_DTR_SHIFT(_mode)	(_mode)
404 #define CP210X_SERIAL_CTS_HANDSHAKE	BIT(3)
405 #define CP210X_SERIAL_DSR_HANDSHAKE	BIT(4)
406 #define CP210X_SERIAL_DCD_HANDSHAKE	BIT(5)
407 #define CP210X_SERIAL_DSR_SENSITIVITY	BIT(6)
408 
409 /* values for cp210x_flow_ctl::ulControlHandshake::CP210X_SERIAL_DTR_MASK */
410 #define CP210X_SERIAL_DTR_INACTIVE	0
411 #define CP210X_SERIAL_DTR_ACTIVE	1
412 #define CP210X_SERIAL_DTR_FLOW_CTL	2
413 
414 /* cp210x_flow_ctl::ulFlowReplace */
415 #define CP210X_SERIAL_AUTO_TRANSMIT	BIT(0)
416 #define CP210X_SERIAL_AUTO_RECEIVE	BIT(1)
417 #define CP210X_SERIAL_ERROR_CHAR	BIT(2)
418 #define CP210X_SERIAL_NULL_STRIPPING	BIT(3)
419 #define CP210X_SERIAL_BREAK_CHAR	BIT(4)
420 #define CP210X_SERIAL_RTS_MASK		GENMASK(7, 6)
421 #define CP210X_SERIAL_RTS_SHIFT(_mode)	(_mode << 6)
422 #define CP210X_SERIAL_XOFF_CONTINUE	BIT(31)
423 
424 /* values for cp210x_flow_ctl::ulFlowReplace::CP210X_SERIAL_RTS_MASK */
425 #define CP210X_SERIAL_RTS_INACTIVE	0
426 #define CP210X_SERIAL_RTS_ACTIVE	1
427 #define CP210X_SERIAL_RTS_FLOW_CTL	2
428 
429 /* CP210X_VENDOR_SPECIFIC, CP210X_GET_DEVICEMODE call reads these 0x2 bytes. */
430 struct cp210x_pin_mode {
431 	u8	eci;
432 	u8	sci;
433 } __packed;
434 
435 #define CP210X_PIN_MODE_MODEM		0
436 #define CP210X_PIN_MODE_GPIO		BIT(0)
437 
438 /*
439  * CP210X_VENDOR_SPECIFIC, CP210X_GET_PORTCONFIG call reads these 0xf bytes.
440  * Structure needs padding due to unused/unspecified bytes.
441  */
442 struct cp210x_config {
443 	__le16	gpio_mode;
444 	u8	__pad0[2];
445 	__le16	reset_state;
446 	u8	__pad1[4];
447 	__le16	suspend_state;
448 	u8	sci_cfg;
449 	u8	eci_cfg;
450 	u8	device_cfg;
451 } __packed;
452 
453 /* GPIO modes */
454 #define CP210X_SCI_GPIO_MODE_OFFSET	9
455 #define CP210X_SCI_GPIO_MODE_MASK	GENMASK(11, 9)
456 
457 #define CP210X_ECI_GPIO_MODE_OFFSET	2
458 #define CP210X_ECI_GPIO_MODE_MASK	GENMASK(3, 2)
459 
460 /* CP2105 port configuration values */
461 #define CP2105_GPIO0_TXLED_MODE		BIT(0)
462 #define CP2105_GPIO1_RXLED_MODE		BIT(1)
463 #define CP2105_GPIO1_RS485_MODE		BIT(2)
464 
465 /* CP210X_VENDOR_SPECIFIC, CP210X_WRITE_LATCH call writes these 0x2 bytes. */
466 struct cp210x_gpio_write {
467 	u8	mask;
468 	u8	state;
469 } __packed;
470 
471 /*
472  * Helper to get interface number when we only have struct usb_serial.
473  */
474 static u8 cp210x_interface_num(struct usb_serial *serial)
475 {
476 	struct usb_host_interface *cur_altsetting;
477 
478 	cur_altsetting = serial->interface->cur_altsetting;
479 
480 	return cur_altsetting->desc.bInterfaceNumber;
481 }
482 
483 /*
484  * Reads a variable-sized block of CP210X_ registers, identified by req.
485  * Returns data into buf in native USB byte order.
486  */
487 static int cp210x_read_reg_block(struct usb_serial_port *port, u8 req,
488 		void *buf, int bufsize)
489 {
490 	struct usb_serial *serial = port->serial;
491 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
492 	void *dmabuf;
493 	int result;
494 
495 	dmabuf = kmalloc(bufsize, GFP_KERNEL);
496 	if (!dmabuf) {
497 		/*
498 		 * FIXME Some callers don't bother to check for error,
499 		 * at least give them consistent junk until they are fixed
500 		 */
501 		memset(buf, 0, bufsize);
502 		return -ENOMEM;
503 	}
504 
505 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
506 			req, REQTYPE_INTERFACE_TO_HOST, 0,
507 			port_priv->bInterfaceNumber, dmabuf, bufsize,
508 			USB_CTRL_SET_TIMEOUT);
509 	if (result == bufsize) {
510 		memcpy(buf, dmabuf, bufsize);
511 		result = 0;
512 	} else {
513 		dev_err(&port->dev, "failed get req 0x%x size %d status: %d\n",
514 				req, bufsize, result);
515 		if (result >= 0)
516 			result = -EIO;
517 
518 		/*
519 		 * FIXME Some callers don't bother to check for error,
520 		 * at least give them consistent junk until they are fixed
521 		 */
522 		memset(buf, 0, bufsize);
523 	}
524 
525 	kfree(dmabuf);
526 
527 	return result;
528 }
529 
530 /*
531  * Reads any 32-bit CP210X_ register identified by req.
532  */
533 static int cp210x_read_u32_reg(struct usb_serial_port *port, u8 req, u32 *val)
534 {
535 	__le32 le32_val;
536 	int err;
537 
538 	err = cp210x_read_reg_block(port, req, &le32_val, sizeof(le32_val));
539 	if (err) {
540 		/*
541 		 * FIXME Some callers don't bother to check for error,
542 		 * at least give them consistent junk until they are fixed
543 		 */
544 		*val = 0;
545 		return err;
546 	}
547 
548 	*val = le32_to_cpu(le32_val);
549 
550 	return 0;
551 }
552 
553 /*
554  * Reads any 16-bit CP210X_ register identified by req.
555  */
556 static int cp210x_read_u16_reg(struct usb_serial_port *port, u8 req, u16 *val)
557 {
558 	__le16 le16_val;
559 	int err;
560 
561 	err = cp210x_read_reg_block(port, req, &le16_val, sizeof(le16_val));
562 	if (err)
563 		return err;
564 
565 	*val = le16_to_cpu(le16_val);
566 
567 	return 0;
568 }
569 
570 /*
571  * Reads any 8-bit CP210X_ register identified by req.
572  */
573 static int cp210x_read_u8_reg(struct usb_serial_port *port, u8 req, u8 *val)
574 {
575 	return cp210x_read_reg_block(port, req, val, sizeof(*val));
576 }
577 
578 /*
579  * Reads a variable-sized vendor block of CP210X_ registers, identified by val.
580  * Returns data into buf in native USB byte order.
581  */
582 static int cp210x_read_vendor_block(struct usb_serial *serial, u8 type, u16 val,
583 				    void *buf, int bufsize)
584 {
585 	void *dmabuf;
586 	int result;
587 
588 	dmabuf = kmalloc(bufsize, GFP_KERNEL);
589 	if (!dmabuf)
590 		return -ENOMEM;
591 
592 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
593 				 CP210X_VENDOR_SPECIFIC, type, val,
594 				 cp210x_interface_num(serial), dmabuf, bufsize,
595 				 USB_CTRL_GET_TIMEOUT);
596 	if (result == bufsize) {
597 		memcpy(buf, dmabuf, bufsize);
598 		result = 0;
599 	} else {
600 		dev_err(&serial->interface->dev,
601 			"failed to get vendor val 0x%04x size %d: %d\n", val,
602 			bufsize, result);
603 		if (result >= 0)
604 			result = -EIO;
605 	}
606 
607 	kfree(dmabuf);
608 
609 	return result;
610 }
611 
612 /*
613  * Writes any 16-bit CP210X_ register (req) whose value is passed
614  * entirely in the wValue field of the USB request.
615  */
616 static int cp210x_write_u16_reg(struct usb_serial_port *port, u8 req, u16 val)
617 {
618 	struct usb_serial *serial = port->serial;
619 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
620 	int result;
621 
622 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
623 			req, REQTYPE_HOST_TO_INTERFACE, val,
624 			port_priv->bInterfaceNumber, NULL, 0,
625 			USB_CTRL_SET_TIMEOUT);
626 	if (result < 0) {
627 		dev_err(&port->dev, "failed set request 0x%x status: %d\n",
628 				req, result);
629 	}
630 
631 	return result;
632 }
633 
634 /*
635  * Writes a variable-sized block of CP210X_ registers, identified by req.
636  * Data in buf must be in native USB byte order.
637  */
638 static int cp210x_write_reg_block(struct usb_serial_port *port, u8 req,
639 		void *buf, int bufsize)
640 {
641 	struct usb_serial *serial = port->serial;
642 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
643 	void *dmabuf;
644 	int result;
645 
646 	dmabuf = kmemdup(buf, bufsize, GFP_KERNEL);
647 	if (!dmabuf)
648 		return -ENOMEM;
649 
650 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
651 			req, REQTYPE_HOST_TO_INTERFACE, 0,
652 			port_priv->bInterfaceNumber, dmabuf, bufsize,
653 			USB_CTRL_SET_TIMEOUT);
654 
655 	kfree(dmabuf);
656 
657 	if (result == bufsize) {
658 		result = 0;
659 	} else {
660 		dev_err(&port->dev, "failed set req 0x%x size %d status: %d\n",
661 				req, bufsize, result);
662 		if (result >= 0)
663 			result = -EIO;
664 	}
665 
666 	return result;
667 }
668 
669 /*
670  * Writes any 32-bit CP210X_ register identified by req.
671  */
672 static int cp210x_write_u32_reg(struct usb_serial_port *port, u8 req, u32 val)
673 {
674 	__le32 le32_val;
675 
676 	le32_val = cpu_to_le32(val);
677 
678 	return cp210x_write_reg_block(port, req, &le32_val, sizeof(le32_val));
679 }
680 
681 #ifdef CONFIG_GPIOLIB
682 /*
683  * Writes a variable-sized vendor block of CP210X_ registers, identified by val.
684  * Data in buf must be in native USB byte order.
685  */
686 static int cp210x_write_vendor_block(struct usb_serial *serial, u8 type,
687 				     u16 val, void *buf, int bufsize)
688 {
689 	void *dmabuf;
690 	int result;
691 
692 	dmabuf = kmemdup(buf, bufsize, GFP_KERNEL);
693 	if (!dmabuf)
694 		return -ENOMEM;
695 
696 	result = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
697 				 CP210X_VENDOR_SPECIFIC, type, val,
698 				 cp210x_interface_num(serial), dmabuf, bufsize,
699 				 USB_CTRL_SET_TIMEOUT);
700 
701 	kfree(dmabuf);
702 
703 	if (result == bufsize) {
704 		result = 0;
705 	} else {
706 		dev_err(&serial->interface->dev,
707 			"failed to set vendor val 0x%04x size %d: %d\n", val,
708 			bufsize, result);
709 		if (result >= 0)
710 			result = -EIO;
711 	}
712 
713 	return result;
714 }
715 #endif
716 
717 /*
718  * Detect CP2108 GET_LINE_CTL bug and activate workaround.
719  * Write a known good value 0x800, read it back.
720  * If it comes back swapped the bug is detected.
721  * Preserve the original register value.
722  */
723 static int cp210x_detect_swapped_line_ctl(struct usb_serial_port *port)
724 {
725 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
726 	u16 line_ctl_save;
727 	u16 line_ctl_test;
728 	int err;
729 
730 	err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, &line_ctl_save);
731 	if (err)
732 		return err;
733 
734 	err = cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, 0x800);
735 	if (err)
736 		return err;
737 
738 	err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, &line_ctl_test);
739 	if (err)
740 		return err;
741 
742 	if (line_ctl_test == 8) {
743 		port_priv->has_swapped_line_ctl = true;
744 		line_ctl_save = swab16(line_ctl_save);
745 	}
746 
747 	return cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, line_ctl_save);
748 }
749 
750 /*
751  * Must always be called instead of cp210x_read_u16_reg(CP210X_GET_LINE_CTL)
752  * to workaround cp2108 bug and get correct value.
753  */
754 static int cp210x_get_line_ctl(struct usb_serial_port *port, u16 *ctl)
755 {
756 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
757 	int err;
758 
759 	err = cp210x_read_u16_reg(port, CP210X_GET_LINE_CTL, ctl);
760 	if (err)
761 		return err;
762 
763 	/* Workaround swapped bytes in 16-bit value from CP210X_GET_LINE_CTL */
764 	if (port_priv->has_swapped_line_ctl)
765 		*ctl = swab16(*ctl);
766 
767 	return 0;
768 }
769 
770 /*
771  * cp210x_quantise_baudrate
772  * Quantises the baud rate as per AN205 Table 1
773  */
774 static unsigned int cp210x_quantise_baudrate(unsigned int baud)
775 {
776 	if (baud <= 300)
777 		baud = 300;
778 	else if (baud <= 600)      baud = 600;
779 	else if (baud <= 1200)     baud = 1200;
780 	else if (baud <= 1800)     baud = 1800;
781 	else if (baud <= 2400)     baud = 2400;
782 	else if (baud <= 4000)     baud = 4000;
783 	else if (baud <= 4803)     baud = 4800;
784 	else if (baud <= 7207)     baud = 7200;
785 	else if (baud <= 9612)     baud = 9600;
786 	else if (baud <= 14428)    baud = 14400;
787 	else if (baud <= 16062)    baud = 16000;
788 	else if (baud <= 19250)    baud = 19200;
789 	else if (baud <= 28912)    baud = 28800;
790 	else if (baud <= 38601)    baud = 38400;
791 	else if (baud <= 51558)    baud = 51200;
792 	else if (baud <= 56280)    baud = 56000;
793 	else if (baud <= 58053)    baud = 57600;
794 	else if (baud <= 64111)    baud = 64000;
795 	else if (baud <= 77608)    baud = 76800;
796 	else if (baud <= 117028)   baud = 115200;
797 	else if (baud <= 129347)   baud = 128000;
798 	else if (baud <= 156868)   baud = 153600;
799 	else if (baud <= 237832)   baud = 230400;
800 	else if (baud <= 254234)   baud = 250000;
801 	else if (baud <= 273066)   baud = 256000;
802 	else if (baud <= 491520)   baud = 460800;
803 	else if (baud <= 567138)   baud = 500000;
804 	else if (baud <= 670254)   baud = 576000;
805 	else if (baud < 1000000)
806 		baud = 921600;
807 	else if (baud > 2000000)
808 		baud = 2000000;
809 	return baud;
810 }
811 
812 static int cp210x_open(struct tty_struct *tty, struct usb_serial_port *port)
813 {
814 	int result;
815 
816 	result = cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_ENABLE);
817 	if (result) {
818 		dev_err(&port->dev, "%s - Unable to enable UART\n", __func__);
819 		return result;
820 	}
821 
822 	/* Configure the termios structure */
823 	cp210x_get_termios(tty, port);
824 
825 	/* The baud rate must be initialised on cp2104 */
826 	if (tty)
827 		cp210x_change_speed(tty, port, NULL);
828 
829 	return usb_serial_generic_open(tty, port);
830 }
831 
832 static void cp210x_close(struct usb_serial_port *port)
833 {
834 	usb_serial_generic_close(port);
835 
836 	/* Clear both queues; cp2108 needs this to avoid an occasional hang */
837 	cp210x_write_u16_reg(port, CP210X_PURGE, PURGE_ALL);
838 
839 	cp210x_write_u16_reg(port, CP210X_IFC_ENABLE, UART_DISABLE);
840 }
841 
842 /*
843  * Read how many bytes are waiting in the TX queue.
844  */
845 static int cp210x_get_tx_queue_byte_count(struct usb_serial_port *port,
846 		u32 *count)
847 {
848 	struct usb_serial *serial = port->serial;
849 	struct cp210x_port_private *port_priv = usb_get_serial_port_data(port);
850 	struct cp210x_comm_status *sts;
851 	int result;
852 
853 	sts = kmalloc(sizeof(*sts), GFP_KERNEL);
854 	if (!sts)
855 		return -ENOMEM;
856 
857 	result = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
858 			CP210X_GET_COMM_STATUS, REQTYPE_INTERFACE_TO_HOST,
859 			0, port_priv->bInterfaceNumber, sts, sizeof(*sts),
860 			USB_CTRL_GET_TIMEOUT);
861 	if (result == sizeof(*sts)) {
862 		*count = le32_to_cpu(sts->ulAmountInOutQueue);
863 		result = 0;
864 	} else {
865 		dev_err(&port->dev, "failed to get comm status: %d\n", result);
866 		if (result >= 0)
867 			result = -EIO;
868 	}
869 
870 	kfree(sts);
871 
872 	return result;
873 }
874 
875 static bool cp210x_tx_empty(struct usb_serial_port *port)
876 {
877 	int err;
878 	u32 count;
879 
880 	err = cp210x_get_tx_queue_byte_count(port, &count);
881 	if (err)
882 		return true;
883 
884 	return !count;
885 }
886 
887 /*
888  * cp210x_get_termios
889  * Reads the baud rate, data bits, parity, stop bits and flow control mode
890  * from the device, corrects any unsupported values, and configures the
891  * termios structure to reflect the state of the device
892  */
893 static void cp210x_get_termios(struct tty_struct *tty,
894 	struct usb_serial_port *port)
895 {
896 	unsigned int baud;
897 
898 	if (tty) {
899 		cp210x_get_termios_port(tty->driver_data,
900 			&tty->termios.c_cflag, &baud);
901 		tty_encode_baud_rate(tty, baud, baud);
902 	} else {
903 		tcflag_t cflag;
904 		cflag = 0;
905 		cp210x_get_termios_port(port, &cflag, &baud);
906 	}
907 }
908 
909 /*
910  * cp210x_get_termios_port
911  * This is the heart of cp210x_get_termios which always uses a &usb_serial_port.
912  */
913 static void cp210x_get_termios_port(struct usb_serial_port *port,
914 	tcflag_t *cflagp, unsigned int *baudp)
915 {
916 	struct device *dev = &port->dev;
917 	tcflag_t cflag;
918 	struct cp210x_flow_ctl flow_ctl;
919 	u32 baud;
920 	u16 bits;
921 	u32 ctl_hs;
922 
923 	cp210x_read_u32_reg(port, CP210X_GET_BAUDRATE, &baud);
924 
925 	dev_dbg(dev, "%s - baud rate = %d\n", __func__, baud);
926 	*baudp = baud;
927 
928 	cflag = *cflagp;
929 
930 	cp210x_get_line_ctl(port, &bits);
931 	cflag &= ~CSIZE;
932 	switch (bits & BITS_DATA_MASK) {
933 	case BITS_DATA_5:
934 		dev_dbg(dev, "%s - data bits = 5\n", __func__);
935 		cflag |= CS5;
936 		break;
937 	case BITS_DATA_6:
938 		dev_dbg(dev, "%s - data bits = 6\n", __func__);
939 		cflag |= CS6;
940 		break;
941 	case BITS_DATA_7:
942 		dev_dbg(dev, "%s - data bits = 7\n", __func__);
943 		cflag |= CS7;
944 		break;
945 	case BITS_DATA_8:
946 		dev_dbg(dev, "%s - data bits = 8\n", __func__);
947 		cflag |= CS8;
948 		break;
949 	case BITS_DATA_9:
950 		dev_dbg(dev, "%s - data bits = 9 (not supported, using 8 data bits)\n", __func__);
951 		cflag |= CS8;
952 		bits &= ~BITS_DATA_MASK;
953 		bits |= BITS_DATA_8;
954 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
955 		break;
956 	default:
957 		dev_dbg(dev, "%s - Unknown number of data bits, using 8\n", __func__);
958 		cflag |= CS8;
959 		bits &= ~BITS_DATA_MASK;
960 		bits |= BITS_DATA_8;
961 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
962 		break;
963 	}
964 
965 	switch (bits & BITS_PARITY_MASK) {
966 	case BITS_PARITY_NONE:
967 		dev_dbg(dev, "%s - parity = NONE\n", __func__);
968 		cflag &= ~PARENB;
969 		break;
970 	case BITS_PARITY_ODD:
971 		dev_dbg(dev, "%s - parity = ODD\n", __func__);
972 		cflag |= (PARENB|PARODD);
973 		break;
974 	case BITS_PARITY_EVEN:
975 		dev_dbg(dev, "%s - parity = EVEN\n", __func__);
976 		cflag &= ~PARODD;
977 		cflag |= PARENB;
978 		break;
979 	case BITS_PARITY_MARK:
980 		dev_dbg(dev, "%s - parity = MARK\n", __func__);
981 		cflag |= (PARENB|PARODD|CMSPAR);
982 		break;
983 	case BITS_PARITY_SPACE:
984 		dev_dbg(dev, "%s - parity = SPACE\n", __func__);
985 		cflag &= ~PARODD;
986 		cflag |= (PARENB|CMSPAR);
987 		break;
988 	default:
989 		dev_dbg(dev, "%s - Unknown parity mode, disabling parity\n", __func__);
990 		cflag &= ~PARENB;
991 		bits &= ~BITS_PARITY_MASK;
992 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
993 		break;
994 	}
995 
996 	cflag &= ~CSTOPB;
997 	switch (bits & BITS_STOP_MASK) {
998 	case BITS_STOP_1:
999 		dev_dbg(dev, "%s - stop bits = 1\n", __func__);
1000 		break;
1001 	case BITS_STOP_1_5:
1002 		dev_dbg(dev, "%s - stop bits = 1.5 (not supported, using 1 stop bit)\n", __func__);
1003 		bits &= ~BITS_STOP_MASK;
1004 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
1005 		break;
1006 	case BITS_STOP_2:
1007 		dev_dbg(dev, "%s - stop bits = 2\n", __func__);
1008 		cflag |= CSTOPB;
1009 		break;
1010 	default:
1011 		dev_dbg(dev, "%s - Unknown number of stop bits, using 1 stop bit\n", __func__);
1012 		bits &= ~BITS_STOP_MASK;
1013 		cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits);
1014 		break;
1015 	}
1016 
1017 	cp210x_read_reg_block(port, CP210X_GET_FLOW, &flow_ctl,
1018 			sizeof(flow_ctl));
1019 	ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake);
1020 	if (ctl_hs & CP210X_SERIAL_CTS_HANDSHAKE) {
1021 		dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
1022 		cflag |= CRTSCTS;
1023 	} else {
1024 		dev_dbg(dev, "%s - flow control = NONE\n", __func__);
1025 		cflag &= ~CRTSCTS;
1026 	}
1027 
1028 	*cflagp = cflag;
1029 }
1030 
1031 /*
1032  * CP2101 supports the following baud rates:
1033  *
1034  *	300, 600, 1200, 1800, 2400, 4800, 7200, 9600, 14400, 19200, 28800,
1035  *	38400, 56000, 57600, 115200, 128000, 230400, 460800, 921600
1036  *
1037  * CP2102 and CP2103 support the following additional rates:
1038  *
1039  *	4000, 16000, 51200, 64000, 76800, 153600, 250000, 256000, 500000,
1040  *	576000
1041  *
1042  * The device will map a requested rate to a supported one, but the result
1043  * of requests for rates greater than 1053257 is undefined (see AN205).
1044  *
1045  * CP2104, CP2105 and CP2110 support most rates up to 2M, 921k and 1M baud,
1046  * respectively, with an error less than 1%. The actual rates are determined
1047  * by
1048  *
1049  *	div = round(freq / (2 x prescale x request))
1050  *	actual = freq / (2 x prescale x div)
1051  *
1052  * For CP2104 and CP2105 freq is 48Mhz and prescale is 4 for request <= 365bps
1053  * or 1 otherwise.
1054  * For CP2110 freq is 24Mhz and prescale is 4 for request <= 300bps or 1
1055  * otherwise.
1056  */
1057 static void cp210x_change_speed(struct tty_struct *tty,
1058 		struct usb_serial_port *port, struct ktermios *old_termios)
1059 {
1060 	u32 baud;
1061 
1062 	baud = tty->termios.c_ospeed;
1063 
1064 	/* This maps the requested rate to a rate valid on cp2102 or cp2103,
1065 	 * or to an arbitrary rate in [1M,2M].
1066 	 *
1067 	 * NOTE: B0 is not implemented.
1068 	 */
1069 	baud = cp210x_quantise_baudrate(baud);
1070 
1071 	dev_dbg(&port->dev, "%s - setting baud rate to %u\n", __func__, baud);
1072 	if (cp210x_write_u32_reg(port, CP210X_SET_BAUDRATE, baud)) {
1073 		dev_warn(&port->dev, "failed to set baud rate to %u\n", baud);
1074 		if (old_termios)
1075 			baud = old_termios->c_ospeed;
1076 		else
1077 			baud = 9600;
1078 	}
1079 
1080 	tty_encode_baud_rate(tty, baud, baud);
1081 }
1082 
1083 static void cp210x_set_termios(struct tty_struct *tty,
1084 		struct usb_serial_port *port, struct ktermios *old_termios)
1085 {
1086 	struct device *dev = &port->dev;
1087 	unsigned int cflag, old_cflag;
1088 	u16 bits;
1089 
1090 	cflag = tty->termios.c_cflag;
1091 	old_cflag = old_termios->c_cflag;
1092 
1093 	if (tty->termios.c_ospeed != old_termios->c_ospeed)
1094 		cp210x_change_speed(tty, port, old_termios);
1095 
1096 	/* If the number of data bits is to be updated */
1097 	if ((cflag & CSIZE) != (old_cflag & CSIZE)) {
1098 		cp210x_get_line_ctl(port, &bits);
1099 		bits &= ~BITS_DATA_MASK;
1100 		switch (cflag & CSIZE) {
1101 		case CS5:
1102 			bits |= BITS_DATA_5;
1103 			dev_dbg(dev, "%s - data bits = 5\n", __func__);
1104 			break;
1105 		case CS6:
1106 			bits |= BITS_DATA_6;
1107 			dev_dbg(dev, "%s - data bits = 6\n", __func__);
1108 			break;
1109 		case CS7:
1110 			bits |= BITS_DATA_7;
1111 			dev_dbg(dev, "%s - data bits = 7\n", __func__);
1112 			break;
1113 		case CS8:
1114 		default:
1115 			bits |= BITS_DATA_8;
1116 			dev_dbg(dev, "%s - data bits = 8\n", __func__);
1117 			break;
1118 		}
1119 		if (cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
1120 			dev_dbg(dev, "Number of data bits requested not supported by device\n");
1121 	}
1122 
1123 	if ((cflag     & (PARENB|PARODD|CMSPAR)) !=
1124 	    (old_cflag & (PARENB|PARODD|CMSPAR))) {
1125 		cp210x_get_line_ctl(port, &bits);
1126 		bits &= ~BITS_PARITY_MASK;
1127 		if (cflag & PARENB) {
1128 			if (cflag & CMSPAR) {
1129 				if (cflag & PARODD) {
1130 					bits |= BITS_PARITY_MARK;
1131 					dev_dbg(dev, "%s - parity = MARK\n", __func__);
1132 				} else {
1133 					bits |= BITS_PARITY_SPACE;
1134 					dev_dbg(dev, "%s - parity = SPACE\n", __func__);
1135 				}
1136 			} else {
1137 				if (cflag & PARODD) {
1138 					bits |= BITS_PARITY_ODD;
1139 					dev_dbg(dev, "%s - parity = ODD\n", __func__);
1140 				} else {
1141 					bits |= BITS_PARITY_EVEN;
1142 					dev_dbg(dev, "%s - parity = EVEN\n", __func__);
1143 				}
1144 			}
1145 		}
1146 		if (cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
1147 			dev_dbg(dev, "Parity mode not supported by device\n");
1148 	}
1149 
1150 	if ((cflag & CSTOPB) != (old_cflag & CSTOPB)) {
1151 		cp210x_get_line_ctl(port, &bits);
1152 		bits &= ~BITS_STOP_MASK;
1153 		if (cflag & CSTOPB) {
1154 			bits |= BITS_STOP_2;
1155 			dev_dbg(dev, "%s - stop bits = 2\n", __func__);
1156 		} else {
1157 			bits |= BITS_STOP_1;
1158 			dev_dbg(dev, "%s - stop bits = 1\n", __func__);
1159 		}
1160 		if (cp210x_write_u16_reg(port, CP210X_SET_LINE_CTL, bits))
1161 			dev_dbg(dev, "Number of stop bits requested not supported by device\n");
1162 	}
1163 
1164 	if ((cflag & CRTSCTS) != (old_cflag & CRTSCTS)) {
1165 		struct cp210x_flow_ctl flow_ctl;
1166 		u32 ctl_hs;
1167 		u32 flow_repl;
1168 
1169 		cp210x_read_reg_block(port, CP210X_GET_FLOW, &flow_ctl,
1170 				sizeof(flow_ctl));
1171 		ctl_hs = le32_to_cpu(flow_ctl.ulControlHandshake);
1172 		flow_repl = le32_to_cpu(flow_ctl.ulFlowReplace);
1173 		dev_dbg(dev, "%s - read ulControlHandshake=0x%08x, ulFlowReplace=0x%08x\n",
1174 				__func__, ctl_hs, flow_repl);
1175 
1176 		ctl_hs &= ~CP210X_SERIAL_DSR_HANDSHAKE;
1177 		ctl_hs &= ~CP210X_SERIAL_DCD_HANDSHAKE;
1178 		ctl_hs &= ~CP210X_SERIAL_DSR_SENSITIVITY;
1179 		ctl_hs &= ~CP210X_SERIAL_DTR_MASK;
1180 		ctl_hs |= CP210X_SERIAL_DTR_SHIFT(CP210X_SERIAL_DTR_ACTIVE);
1181 		if (cflag & CRTSCTS) {
1182 			ctl_hs |= CP210X_SERIAL_CTS_HANDSHAKE;
1183 
1184 			flow_repl &= ~CP210X_SERIAL_RTS_MASK;
1185 			flow_repl |= CP210X_SERIAL_RTS_SHIFT(
1186 					CP210X_SERIAL_RTS_FLOW_CTL);
1187 			dev_dbg(dev, "%s - flow control = CRTSCTS\n", __func__);
1188 		} else {
1189 			ctl_hs &= ~CP210X_SERIAL_CTS_HANDSHAKE;
1190 
1191 			flow_repl &= ~CP210X_SERIAL_RTS_MASK;
1192 			flow_repl |= CP210X_SERIAL_RTS_SHIFT(
1193 					CP210X_SERIAL_RTS_ACTIVE);
1194 			dev_dbg(dev, "%s - flow control = NONE\n", __func__);
1195 		}
1196 
1197 		dev_dbg(dev, "%s - write ulControlHandshake=0x%08x, ulFlowReplace=0x%08x\n",
1198 				__func__, ctl_hs, flow_repl);
1199 		flow_ctl.ulControlHandshake = cpu_to_le32(ctl_hs);
1200 		flow_ctl.ulFlowReplace = cpu_to_le32(flow_repl);
1201 		cp210x_write_reg_block(port, CP210X_SET_FLOW, &flow_ctl,
1202 				sizeof(flow_ctl));
1203 	}
1204 
1205 }
1206 
1207 static int cp210x_tiocmset(struct tty_struct *tty,
1208 		unsigned int set, unsigned int clear)
1209 {
1210 	struct usb_serial_port *port = tty->driver_data;
1211 	return cp210x_tiocmset_port(port, set, clear);
1212 }
1213 
1214 static int cp210x_tiocmset_port(struct usb_serial_port *port,
1215 		unsigned int set, unsigned int clear)
1216 {
1217 	u16 control = 0;
1218 
1219 	if (set & TIOCM_RTS) {
1220 		control |= CONTROL_RTS;
1221 		control |= CONTROL_WRITE_RTS;
1222 	}
1223 	if (set & TIOCM_DTR) {
1224 		control |= CONTROL_DTR;
1225 		control |= CONTROL_WRITE_DTR;
1226 	}
1227 	if (clear & TIOCM_RTS) {
1228 		control &= ~CONTROL_RTS;
1229 		control |= CONTROL_WRITE_RTS;
1230 	}
1231 	if (clear & TIOCM_DTR) {
1232 		control &= ~CONTROL_DTR;
1233 		control |= CONTROL_WRITE_DTR;
1234 	}
1235 
1236 	dev_dbg(&port->dev, "%s - control = 0x%.4x\n", __func__, control);
1237 
1238 	return cp210x_write_u16_reg(port, CP210X_SET_MHS, control);
1239 }
1240 
1241 static void cp210x_dtr_rts(struct usb_serial_port *p, int on)
1242 {
1243 	if (on)
1244 		cp210x_tiocmset_port(p, TIOCM_DTR|TIOCM_RTS, 0);
1245 	else
1246 		cp210x_tiocmset_port(p, 0, TIOCM_DTR|TIOCM_RTS);
1247 }
1248 
1249 static int cp210x_tiocmget(struct tty_struct *tty)
1250 {
1251 	struct usb_serial_port *port = tty->driver_data;
1252 	u8 control;
1253 	int result;
1254 
1255 	result = cp210x_read_u8_reg(port, CP210X_GET_MDMSTS, &control);
1256 	if (result)
1257 		return result;
1258 
1259 	result = ((control & CONTROL_DTR) ? TIOCM_DTR : 0)
1260 		|((control & CONTROL_RTS) ? TIOCM_RTS : 0)
1261 		|((control & CONTROL_CTS) ? TIOCM_CTS : 0)
1262 		|((control & CONTROL_DSR) ? TIOCM_DSR : 0)
1263 		|((control & CONTROL_RING)? TIOCM_RI  : 0)
1264 		|((control & CONTROL_DCD) ? TIOCM_CD  : 0);
1265 
1266 	dev_dbg(&port->dev, "%s - control = 0x%.2x\n", __func__, control);
1267 
1268 	return result;
1269 }
1270 
1271 static void cp210x_break_ctl(struct tty_struct *tty, int break_state)
1272 {
1273 	struct usb_serial_port *port = tty->driver_data;
1274 	u16 state;
1275 
1276 	if (break_state == 0)
1277 		state = BREAK_OFF;
1278 	else
1279 		state = BREAK_ON;
1280 	dev_dbg(&port->dev, "%s - turning break %s\n", __func__,
1281 		state == BREAK_OFF ? "off" : "on");
1282 	cp210x_write_u16_reg(port, CP210X_SET_BREAK, state);
1283 }
1284 
1285 #ifdef CONFIG_GPIOLIB
1286 static int cp210x_gpio_request(struct gpio_chip *gc, unsigned int offset)
1287 {
1288 	struct usb_serial *serial = gpiochip_get_data(gc);
1289 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1290 
1291 	switch (offset) {
1292 	case 0:
1293 		if (priv->config & CP2105_GPIO0_TXLED_MODE)
1294 			return -ENODEV;
1295 		break;
1296 	case 1:
1297 		if (priv->config & (CP2105_GPIO1_RXLED_MODE |
1298 				    CP2105_GPIO1_RS485_MODE))
1299 			return -ENODEV;
1300 		break;
1301 	}
1302 
1303 	return 0;
1304 }
1305 
1306 static int cp210x_gpio_get(struct gpio_chip *gc, unsigned int gpio)
1307 {
1308 	struct usb_serial *serial = gpiochip_get_data(gc);
1309 	int result;
1310 	u8 buf;
1311 
1312 	result = cp210x_read_vendor_block(serial, REQTYPE_INTERFACE_TO_HOST,
1313 					  CP210X_READ_LATCH, &buf, sizeof(buf));
1314 	if (result < 0)
1315 		return result;
1316 
1317 	return !!(buf & BIT(gpio));
1318 }
1319 
1320 static void cp210x_gpio_set(struct gpio_chip *gc, unsigned int gpio, int value)
1321 {
1322 	struct usb_serial *serial = gpiochip_get_data(gc);
1323 	struct cp210x_gpio_write buf;
1324 
1325 	if (value == 1)
1326 		buf.state = BIT(gpio);
1327 	else
1328 		buf.state = 0;
1329 
1330 	buf.mask = BIT(gpio);
1331 
1332 	cp210x_write_vendor_block(serial, REQTYPE_HOST_TO_INTERFACE,
1333 				  CP210X_WRITE_LATCH, &buf, sizeof(buf));
1334 }
1335 
1336 static int cp210x_gpio_direction_get(struct gpio_chip *gc, unsigned int gpio)
1337 {
1338 	/* Hardware does not support an input mode */
1339 	return 0;
1340 }
1341 
1342 static int cp210x_gpio_direction_input(struct gpio_chip *gc, unsigned int gpio)
1343 {
1344 	/* Hardware does not support an input mode */
1345 	return -ENOTSUPP;
1346 }
1347 
1348 static int cp210x_gpio_direction_output(struct gpio_chip *gc, unsigned int gpio,
1349 					int value)
1350 {
1351 	return 0;
1352 }
1353 
1354 static int cp210x_gpio_set_config(struct gpio_chip *gc, unsigned int gpio,
1355 				  unsigned long config)
1356 {
1357 	struct usb_serial *serial = gpiochip_get_data(gc);
1358 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1359 	enum pin_config_param param = pinconf_to_config_param(config);
1360 
1361 	/* Succeed only if in correct mode (this can't be set at runtime) */
1362 	if ((param == PIN_CONFIG_DRIVE_PUSH_PULL) &&
1363 	    (priv->gpio_mode & BIT(gpio)))
1364 		return 0;
1365 
1366 	if ((param == PIN_CONFIG_DRIVE_OPEN_DRAIN) &&
1367 	    !(priv->gpio_mode & BIT(gpio)))
1368 		return 0;
1369 
1370 	return -ENOTSUPP;
1371 }
1372 
1373 /*
1374  * This function is for configuring GPIO using shared pins, where other signals
1375  * are made unavailable by configuring the use of GPIO. This is believed to be
1376  * only applicable to the cp2105 at this point, the other devices supported by
1377  * this driver that provide GPIO do so in a way that does not impact other
1378  * signals and are thus expected to have very different initialisation.
1379  */
1380 static int cp2105_shared_gpio_init(struct usb_serial *serial)
1381 {
1382 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1383 	struct cp210x_pin_mode mode;
1384 	struct cp210x_config config;
1385 	u8 intf_num = cp210x_interface_num(serial);
1386 	int result;
1387 
1388 	result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
1389 					  CP210X_GET_DEVICEMODE, &mode,
1390 					  sizeof(mode));
1391 	if (result < 0)
1392 		return result;
1393 
1394 	result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
1395 					  CP210X_GET_PORTCONFIG, &config,
1396 					  sizeof(config));
1397 	if (result < 0)
1398 		return result;
1399 
1400 	/*  2 banks of GPIO - One for the pins taken from each serial port */
1401 	if (intf_num == 0) {
1402 		if (mode.eci == CP210X_PIN_MODE_MODEM)
1403 			return 0;
1404 
1405 		priv->config = config.eci_cfg;
1406 		priv->gpio_mode = (u8)((le16_to_cpu(config.gpio_mode) &
1407 						CP210X_ECI_GPIO_MODE_MASK) >>
1408 						CP210X_ECI_GPIO_MODE_OFFSET);
1409 		priv->gc.ngpio = 2;
1410 	} else if (intf_num == 1) {
1411 		if (mode.sci == CP210X_PIN_MODE_MODEM)
1412 			return 0;
1413 
1414 		priv->config = config.sci_cfg;
1415 		priv->gpio_mode = (u8)((le16_to_cpu(config.gpio_mode) &
1416 						CP210X_SCI_GPIO_MODE_MASK) >>
1417 						CP210X_SCI_GPIO_MODE_OFFSET);
1418 		priv->gc.ngpio = 3;
1419 	} else {
1420 		return -ENODEV;
1421 	}
1422 
1423 	priv->gc.label = "cp210x";
1424 	priv->gc.request = cp210x_gpio_request;
1425 	priv->gc.get_direction = cp210x_gpio_direction_get;
1426 	priv->gc.direction_input = cp210x_gpio_direction_input;
1427 	priv->gc.direction_output = cp210x_gpio_direction_output;
1428 	priv->gc.get = cp210x_gpio_get;
1429 	priv->gc.set = cp210x_gpio_set;
1430 	priv->gc.set_config = cp210x_gpio_set_config;
1431 	priv->gc.owner = THIS_MODULE;
1432 	priv->gc.parent = &serial->interface->dev;
1433 	priv->gc.base = -1;
1434 	priv->gc.can_sleep = true;
1435 
1436 	result = gpiochip_add_data(&priv->gc, serial);
1437 	if (!result)
1438 		priv->gpio_registered = true;
1439 
1440 	return result;
1441 }
1442 
1443 static void cp210x_gpio_remove(struct usb_serial *serial)
1444 {
1445 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1446 
1447 	if (priv->gpio_registered) {
1448 		gpiochip_remove(&priv->gc);
1449 		priv->gpio_registered = false;
1450 	}
1451 }
1452 
1453 #else
1454 
1455 static int cp2105_shared_gpio_init(struct usb_serial *serial)
1456 {
1457 	return 0;
1458 }
1459 
1460 static void cp210x_gpio_remove(struct usb_serial *serial)
1461 {
1462 	/* Nothing to do */
1463 }
1464 
1465 #endif
1466 
1467 static int cp210x_port_probe(struct usb_serial_port *port)
1468 {
1469 	struct usb_serial *serial = port->serial;
1470 	struct cp210x_port_private *port_priv;
1471 	int ret;
1472 
1473 	port_priv = kzalloc(sizeof(*port_priv), GFP_KERNEL);
1474 	if (!port_priv)
1475 		return -ENOMEM;
1476 
1477 	port_priv->bInterfaceNumber = cp210x_interface_num(serial);
1478 
1479 	usb_set_serial_port_data(port, port_priv);
1480 
1481 	ret = cp210x_detect_swapped_line_ctl(port);
1482 	if (ret) {
1483 		kfree(port_priv);
1484 		return ret;
1485 	}
1486 
1487 	return 0;
1488 }
1489 
1490 static int cp210x_port_remove(struct usb_serial_port *port)
1491 {
1492 	struct cp210x_port_private *port_priv;
1493 
1494 	port_priv = usb_get_serial_port_data(port);
1495 	kfree(port_priv);
1496 
1497 	return 0;
1498 }
1499 
1500 static int cp210x_attach(struct usb_serial *serial)
1501 {
1502 	int result;
1503 	struct cp210x_serial_private *priv;
1504 
1505 	priv = kzalloc(sizeof(*priv), GFP_KERNEL);
1506 	if (!priv)
1507 		return -ENOMEM;
1508 
1509 	result = cp210x_read_vendor_block(serial, REQTYPE_DEVICE_TO_HOST,
1510 					  CP210X_GET_PARTNUM, &priv->partnum,
1511 					  sizeof(priv->partnum));
1512 	if (result < 0) {
1513 		dev_warn(&serial->interface->dev,
1514 			 "querying part number failed\n");
1515 		priv->partnum = CP210X_PARTNUM_UNKNOWN;
1516 	}
1517 
1518 	usb_set_serial_data(serial, priv);
1519 
1520 	if (priv->partnum == CP210X_PARTNUM_CP2105) {
1521 		result = cp2105_shared_gpio_init(serial);
1522 		if (result < 0) {
1523 			dev_err(&serial->interface->dev,
1524 				"GPIO initialisation failed, continuing without GPIO support\n");
1525 		}
1526 	}
1527 
1528 	return 0;
1529 }
1530 
1531 static void cp210x_disconnect(struct usb_serial *serial)
1532 {
1533 	cp210x_gpio_remove(serial);
1534 }
1535 
1536 static void cp210x_release(struct usb_serial *serial)
1537 {
1538 	struct cp210x_serial_private *priv = usb_get_serial_data(serial);
1539 
1540 	cp210x_gpio_remove(serial);
1541 
1542 	kfree(priv);
1543 }
1544 
1545 module_usb_serial_driver(serial_drivers, id_table);
1546 
1547 MODULE_DESCRIPTION(DRIVER_DESC);
1548 MODULE_LICENSE("GPL v2");
1549