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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * MaxLinear/Exar USB to Serial driver
4 *
5 * Copyright (c) 2020 Manivannan Sadhasivam <mani@kernel.org>
6 * Copyright (c) 2021 Johan Hovold <johan@kernel.org>
7 *
8 * Based on the initial driver written by Patong Yang:
9 *
10 * https://lore.kernel.org/r/20180404070634.nhspvmxcjwfgjkcv@advantechmxl-desktop
11 *
12 * Copyright (c) 2018 Patong Yang <patong.mxl@gmail.com>
13 */
14
15#include <linux/kernel.h>
16#include <linux/module.h>
17#include <linux/slab.h>
18#include <linux/tty.h>
19#include <linux/usb.h>
20#include <linux/usb/cdc.h>
21#include <linux/usb/serial.h>
22
23struct xr_txrx_clk_mask {
24 u16 tx;
25 u16 rx0;
26 u16 rx1;
27};
28
29#define XR_INT_OSC_HZ 48000000U
30#define XR21V141X_MIN_SPEED 46U
31#define XR21V141X_MAX_SPEED XR_INT_OSC_HZ
32
33/* XR21V141X register blocks */
34#define XR21V141X_UART_REG_BLOCK 0
35#define XR21V141X_UM_REG_BLOCK 4
36#define XR21V141X_UART_CUSTOM_BLOCK 0x66
37
38/* XR21V141X UART registers */
39#define XR21V141X_CLOCK_DIVISOR_0 0x04
40#define XR21V141X_CLOCK_DIVISOR_1 0x05
41#define XR21V141X_CLOCK_DIVISOR_2 0x06
42#define XR21V141X_TX_CLOCK_MASK_0 0x07
43#define XR21V141X_TX_CLOCK_MASK_1 0x08
44#define XR21V141X_RX_CLOCK_MASK_0 0x09
45#define XR21V141X_RX_CLOCK_MASK_1 0x0a
46#define XR21V141X_REG_FORMAT 0x0b
47
48/* XR21V141X UART Manager registers */
49#define XR21V141X_UM_FIFO_ENABLE_REG 0x10
50#define XR21V141X_UM_ENABLE_TX_FIFO 0x01
51#define XR21V141X_UM_ENABLE_RX_FIFO 0x02
52
53#define XR21V141X_UM_RX_FIFO_RESET 0x18
54#define XR21V141X_UM_TX_FIFO_RESET 0x1c
55
56#define XR_UART_ENABLE_TX 0x1
57#define XR_UART_ENABLE_RX 0x2
58
59#define XR_GPIO_RI BIT(0)
60#define XR_GPIO_CD BIT(1)
61#define XR_GPIO_DSR BIT(2)
62#define XR_GPIO_DTR BIT(3)
63#define XR_GPIO_CTS BIT(4)
64#define XR_GPIO_RTS BIT(5)
65#define XR_GPIO_CLK BIT(6)
66#define XR_GPIO_XEN BIT(7)
67#define XR_GPIO_TXT BIT(8)
68#define XR_GPIO_RXT BIT(9)
69
70#define XR_UART_DATA_MASK GENMASK(3, 0)
71#define XR_UART_DATA_7 0x7
72#define XR_UART_DATA_8 0x8
73
74#define XR_UART_PARITY_MASK GENMASK(6, 4)
75#define XR_UART_PARITY_SHIFT 4
76#define XR_UART_PARITY_NONE (0x0 << XR_UART_PARITY_SHIFT)
77#define XR_UART_PARITY_ODD (0x1 << XR_UART_PARITY_SHIFT)
78#define XR_UART_PARITY_EVEN (0x2 << XR_UART_PARITY_SHIFT)
79#define XR_UART_PARITY_MARK (0x3 << XR_UART_PARITY_SHIFT)
80#define XR_UART_PARITY_SPACE (0x4 << XR_UART_PARITY_SHIFT)
81
82#define XR_UART_STOP_MASK BIT(7)
83#define XR_UART_STOP_SHIFT 7
84#define XR_UART_STOP_1 (0x0 << XR_UART_STOP_SHIFT)
85#define XR_UART_STOP_2 (0x1 << XR_UART_STOP_SHIFT)
86
87#define XR_UART_FLOW_MODE_NONE 0x0
88#define XR_UART_FLOW_MODE_HW 0x1
89#define XR_UART_FLOW_MODE_SW 0x2
90
91#define XR_GPIO_MODE_SEL_MASK GENMASK(2, 0)
92#define XR_GPIO_MODE_SEL_RTS_CTS 0x1
93#define XR_GPIO_MODE_SEL_DTR_DSR 0x2
94#define XR_GPIO_MODE_SEL_RS485 0x3
95#define XR_GPIO_MODE_SEL_RS485_ADDR 0x4
96#define XR_GPIO_MODE_RS485_TX_H 0x8
97#define XR_GPIO_MODE_TX_TOGGLE 0x100
98#define XR_GPIO_MODE_RX_TOGGLE 0x200
99
100#define XR_FIFO_RESET 0x1
101
102#define XR_CUSTOM_DRIVER_ACTIVE 0x1
103
104static int xr21v141x_uart_enable(struct usb_serial_port *port);
105static int xr21v141x_uart_disable(struct usb_serial_port *port);
106static int xr21v141x_fifo_reset(struct usb_serial_port *port);
107static void xr21v141x_set_line_settings(struct tty_struct *tty,
108 struct usb_serial_port *port,
109 const struct ktermios *old_termios);
110
111struct xr_type {
112 int reg_width;
113 u8 reg_recipient;
114 u8 set_reg;
115 u8 get_reg;
116
117 u16 uart_enable;
118 u16 flow_control;
119 u16 xon_char;
120 u16 xoff_char;
121 u16 tx_break;
122 u16 gpio_mode;
123 u16 gpio_direction;
124 u16 gpio_set;
125 u16 gpio_clear;
126 u16 gpio_status;
127 u16 tx_fifo_reset;
128 u16 rx_fifo_reset;
129 u16 custom_driver;
130
131 bool have_5_6_bit_mode;
132 bool have_xmit_toggle;
133
134 int (*enable)(struct usb_serial_port *port);
135 int (*disable)(struct usb_serial_port *port);
136 int (*fifo_reset)(struct usb_serial_port *port);
137 void (*set_line_settings)(struct tty_struct *tty,
138 struct usb_serial_port *port,
139 const struct ktermios *old_termios);
140};
141
142enum xr_type_id {
143 XR21V141X,
144 XR21B142X,
145 XR21B1411,
146 XR2280X,
147 XR_TYPE_COUNT,
148};
149
150static const struct xr_type xr_types[] = {
151 [XR21V141X] = {
152 .reg_width = 8,
153 .reg_recipient = USB_RECIP_DEVICE,
154 .set_reg = 0x00,
155 .get_reg = 0x01,
156
157 .uart_enable = 0x03,
158 .flow_control = 0x0c,
159 .xon_char = 0x10,
160 .xoff_char = 0x11,
161 .tx_break = 0x14,
162 .gpio_mode = 0x1a,
163 .gpio_direction = 0x1b,
164 .gpio_set = 0x1d,
165 .gpio_clear = 0x1e,
166 .gpio_status = 0x1f,
167
168 .enable = xr21v141x_uart_enable,
169 .disable = xr21v141x_uart_disable,
170 .fifo_reset = xr21v141x_fifo_reset,
171 .set_line_settings = xr21v141x_set_line_settings,
172 },
173 [XR21B142X] = {
174 .reg_width = 16,
175 .reg_recipient = USB_RECIP_INTERFACE,
176 .set_reg = 0x00,
177 .get_reg = 0x00,
178
179 .uart_enable = 0x00,
180 .flow_control = 0x06,
181 .xon_char = 0x07,
182 .xoff_char = 0x08,
183 .tx_break = 0x0a,
184 .gpio_mode = 0x0c,
185 .gpio_direction = 0x0d,
186 .gpio_set = 0x0e,
187 .gpio_clear = 0x0f,
188 .gpio_status = 0x10,
189 .tx_fifo_reset = 0x40,
190 .rx_fifo_reset = 0x43,
191 .custom_driver = 0x60,
192
193 .have_5_6_bit_mode = true,
194 .have_xmit_toggle = true,
195 },
196 [XR21B1411] = {
197 .reg_width = 12,
198 .reg_recipient = USB_RECIP_DEVICE,
199 .set_reg = 0x00,
200 .get_reg = 0x01,
201
202 .uart_enable = 0xc00,
203 .flow_control = 0xc06,
204 .xon_char = 0xc07,
205 .xoff_char = 0xc08,
206 .tx_break = 0xc0a,
207 .gpio_mode = 0xc0c,
208 .gpio_direction = 0xc0d,
209 .gpio_set = 0xc0e,
210 .gpio_clear = 0xc0f,
211 .gpio_status = 0xc10,
212 .tx_fifo_reset = 0xc80,
213 .rx_fifo_reset = 0xcc0,
214 .custom_driver = 0x20d,
215 },
216 [XR2280X] = {
217 .reg_width = 16,
218 .reg_recipient = USB_RECIP_DEVICE,
219 .set_reg = 0x05,
220 .get_reg = 0x05,
221
222 .uart_enable = 0x40,
223 .flow_control = 0x46,
224 .xon_char = 0x47,
225 .xoff_char = 0x48,
226 .tx_break = 0x4a,
227 .gpio_mode = 0x4c,
228 .gpio_direction = 0x4d,
229 .gpio_set = 0x4e,
230 .gpio_clear = 0x4f,
231 .gpio_status = 0x50,
232 .tx_fifo_reset = 0x60,
233 .rx_fifo_reset = 0x63,
234 .custom_driver = 0x81,
235 },
236};
237
238struct xr_data {
239 const struct xr_type *type;
240 u8 channel; /* zero-based index or interface number */
241 struct serial_rs485 rs485;
242};
243
244static int xr_set_reg(struct usb_serial_port *port, u8 channel, u16 reg, u16 val)
245{
246 struct xr_data *data = usb_get_serial_port_data(port);
247 const struct xr_type *type = data->type;
248 struct usb_serial *serial = port->serial;
249 int ret;
250
251 ret = usb_control_msg(serial->dev, usb_sndctrlpipe(serial->dev, 0),
252 type->set_reg,
253 USB_DIR_OUT | USB_TYPE_VENDOR | type->reg_recipient,
254 val, (channel << 8) | reg, NULL, 0,
255 USB_CTRL_SET_TIMEOUT);
256 if (ret < 0) {
257 dev_err(&port->dev, "Failed to set reg 0x%02x: %d\n", reg, ret);
258 return ret;
259 }
260
261 return 0;
262}
263
264static int xr_get_reg(struct usb_serial_port *port, u8 channel, u16 reg, u16 *val)
265{
266 struct xr_data *data = usb_get_serial_port_data(port);
267 const struct xr_type *type = data->type;
268 struct usb_serial *serial = port->serial;
269 u8 *dmabuf;
270 int ret, len;
271
272 if (type->reg_width == 8)
273 len = 1;
274 else
275 len = 2;
276
277 dmabuf = kmalloc(len, GFP_KERNEL);
278 if (!dmabuf)
279 return -ENOMEM;
280
281 ret = usb_control_msg(serial->dev, usb_rcvctrlpipe(serial->dev, 0),
282 type->get_reg,
283 USB_DIR_IN | USB_TYPE_VENDOR | type->reg_recipient,
284 0, (channel << 8) | reg, dmabuf, len,
285 USB_CTRL_GET_TIMEOUT);
286 if (ret == len) {
287 if (len == 2)
288 *val = le16_to_cpup((__le16 *)dmabuf);
289 else
290 *val = *dmabuf;
291 ret = 0;
292 } else {
293 dev_err(&port->dev, "Failed to get reg 0x%02x: %d\n", reg, ret);
294 if (ret >= 0)
295 ret = -EIO;
296 }
297
298 kfree(dmabuf);
299
300 return ret;
301}
302
303static int xr_set_reg_uart(struct usb_serial_port *port, u16 reg, u16 val)
304{
305 struct xr_data *data = usb_get_serial_port_data(port);
306
307 return xr_set_reg(port, data->channel, reg, val);
308}
309
310static int xr_get_reg_uart(struct usb_serial_port *port, u16 reg, u16 *val)
311{
312 struct xr_data *data = usb_get_serial_port_data(port);
313
314 return xr_get_reg(port, data->channel, reg, val);
315}
316
317static int xr_set_reg_um(struct usb_serial_port *port, u8 reg_base, u8 val)
318{
319 struct xr_data *data = usb_get_serial_port_data(port);
320 u8 reg;
321
322 reg = reg_base + data->channel;
323
324 return xr_set_reg(port, XR21V141X_UM_REG_BLOCK, reg, val);
325}
326
327static int __xr_uart_enable(struct usb_serial_port *port)
328{
329 struct xr_data *data = usb_get_serial_port_data(port);
330
331 return xr_set_reg_uart(port, data->type->uart_enable,
332 XR_UART_ENABLE_TX | XR_UART_ENABLE_RX);
333}
334
335static int __xr_uart_disable(struct usb_serial_port *port)
336{
337 struct xr_data *data = usb_get_serial_port_data(port);
338
339 return xr_set_reg_uart(port, data->type->uart_enable, 0);
340}
341
342/*
343 * According to datasheet, below is the recommended sequence for enabling UART
344 * module in XR21V141X:
345 *
346 * Enable Tx FIFO
347 * Enable Tx and Rx
348 * Enable Rx FIFO
349 */
350static int xr21v141x_uart_enable(struct usb_serial_port *port)
351{
352 int ret;
353
354 ret = xr_set_reg_um(port, XR21V141X_UM_FIFO_ENABLE_REG,
355 XR21V141X_UM_ENABLE_TX_FIFO);
356 if (ret)
357 return ret;
358
359 ret = __xr_uart_enable(port);
360 if (ret)
361 return ret;
362
363 ret = xr_set_reg_um(port, XR21V141X_UM_FIFO_ENABLE_REG,
364 XR21V141X_UM_ENABLE_TX_FIFO | XR21V141X_UM_ENABLE_RX_FIFO);
365 if (ret)
366 __xr_uart_disable(port);
367
368 return ret;
369}
370
371static int xr21v141x_uart_disable(struct usb_serial_port *port)
372{
373 int ret;
374
375 ret = __xr_uart_disable(port);
376 if (ret)
377 return ret;
378
379 ret = xr_set_reg_um(port, XR21V141X_UM_FIFO_ENABLE_REG, 0);
380
381 return ret;
382}
383
384static int xr_uart_enable(struct usb_serial_port *port)
385{
386 struct xr_data *data = usb_get_serial_port_data(port);
387
388 if (data->type->enable)
389 return data->type->enable(port);
390
391 return __xr_uart_enable(port);
392}
393
394static int xr_uart_disable(struct usb_serial_port *port)
395{
396 struct xr_data *data = usb_get_serial_port_data(port);
397
398 if (data->type->disable)
399 return data->type->disable(port);
400
401 return __xr_uart_disable(port);
402}
403
404static int xr21v141x_fifo_reset(struct usb_serial_port *port)
405{
406 int ret;
407
408 ret = xr_set_reg_um(port, XR21V141X_UM_TX_FIFO_RESET, XR_FIFO_RESET);
409 if (ret)
410 return ret;
411
412 ret = xr_set_reg_um(port, XR21V141X_UM_RX_FIFO_RESET, XR_FIFO_RESET);
413 if (ret)
414 return ret;
415
416 return 0;
417}
418
419static int xr_fifo_reset(struct usb_serial_port *port)
420{
421 struct xr_data *data = usb_get_serial_port_data(port);
422 int ret;
423
424 if (data->type->fifo_reset)
425 return data->type->fifo_reset(port);
426
427 ret = xr_set_reg_uart(port, data->type->tx_fifo_reset, XR_FIFO_RESET);
428 if (ret)
429 return ret;
430
431 ret = xr_set_reg_uart(port, data->type->rx_fifo_reset, XR_FIFO_RESET);
432 if (ret)
433 return ret;
434
435 return 0;
436}
437
438static int xr_tiocmget(struct tty_struct *tty)
439{
440 struct usb_serial_port *port = tty->driver_data;
441 struct xr_data *data = usb_get_serial_port_data(port);
442 u16 status;
443 int ret;
444
445 ret = xr_get_reg_uart(port, data->type->gpio_status, &status);
446 if (ret)
447 return ret;
448
449 /*
450 * Modem control pins are active low, so reading '0' means it is active
451 * and '1' means not active.
452 */
453 ret = ((status & XR_GPIO_DTR) ? 0 : TIOCM_DTR) |
454 ((status & XR_GPIO_RTS) ? 0 : TIOCM_RTS) |
455 ((status & XR_GPIO_CTS) ? 0 : TIOCM_CTS) |
456 ((status & XR_GPIO_DSR) ? 0 : TIOCM_DSR) |
457 ((status & XR_GPIO_RI) ? 0 : TIOCM_RI) |
458 ((status & XR_GPIO_CD) ? 0 : TIOCM_CD);
459
460 return ret;
461}
462
463static int xr_tiocmset_port(struct usb_serial_port *port,
464 unsigned int set, unsigned int clear)
465{
466 struct xr_data *data = usb_get_serial_port_data(port);
467 const struct xr_type *type = data->type;
468 u16 gpio_set = 0;
469 u16 gpio_clr = 0;
470 int ret = 0;
471
472 /* Modem control pins are active low, so set & clr are swapped */
473 if (set & TIOCM_RTS)
474 gpio_clr |= XR_GPIO_RTS;
475 if (set & TIOCM_DTR)
476 gpio_clr |= XR_GPIO_DTR;
477 if (clear & TIOCM_RTS)
478 gpio_set |= XR_GPIO_RTS;
479 if (clear & TIOCM_DTR)
480 gpio_set |= XR_GPIO_DTR;
481
482 /* Writing '0' to gpio_{set/clr} bits has no effect, so no need to do */
483 if (gpio_clr)
484 ret = xr_set_reg_uart(port, type->gpio_clear, gpio_clr);
485
486 if (gpio_set)
487 ret = xr_set_reg_uart(port, type->gpio_set, gpio_set);
488
489 return ret;
490}
491
492static int xr_tiocmset(struct tty_struct *tty,
493 unsigned int set, unsigned int clear)
494{
495 struct usb_serial_port *port = tty->driver_data;
496
497 return xr_tiocmset_port(port, set, clear);
498}
499
500static void xr_dtr_rts(struct usb_serial_port *port, int on)
501{
502 if (on)
503 xr_tiocmset_port(port, TIOCM_DTR | TIOCM_RTS, 0);
504 else
505 xr_tiocmset_port(port, 0, TIOCM_DTR | TIOCM_RTS);
506}
507
508static int xr_break_ctl(struct tty_struct *tty, int break_state)
509{
510 struct usb_serial_port *port = tty->driver_data;
511 struct xr_data *data = usb_get_serial_port_data(port);
512 const struct xr_type *type = data->type;
513 u16 state;
514
515 if (break_state == 0)
516 state = 0;
517 else
518 state = GENMASK(type->reg_width - 1, 0);
519
520 dev_dbg(&port->dev, "Turning break %s\n", state == 0 ? "off" : "on");
521
522 return xr_set_reg_uart(port, type->tx_break, state);
523}
524
525/* Tx and Rx clock mask values obtained from section 3.3.4 of datasheet */
526static const struct xr_txrx_clk_mask xr21v141x_txrx_clk_masks[] = {
527 { 0x000, 0x000, 0x000 },
528 { 0x000, 0x000, 0x000 },
529 { 0x100, 0x000, 0x100 },
530 { 0x020, 0x400, 0x020 },
531 { 0x010, 0x100, 0x010 },
532 { 0x208, 0x040, 0x208 },
533 { 0x104, 0x820, 0x108 },
534 { 0x844, 0x210, 0x884 },
535 { 0x444, 0x110, 0x444 },
536 { 0x122, 0x888, 0x224 },
537 { 0x912, 0x448, 0x924 },
538 { 0x492, 0x248, 0x492 },
539 { 0x252, 0x928, 0x292 },
540 { 0x94a, 0x4a4, 0xa52 },
541 { 0x52a, 0xaa4, 0x54a },
542 { 0xaaa, 0x954, 0x4aa },
543 { 0xaaa, 0x554, 0xaaa },
544 { 0x555, 0xad4, 0x5aa },
545 { 0xb55, 0xab4, 0x55a },
546 { 0x6b5, 0x5ac, 0xb56 },
547 { 0x5b5, 0xd6c, 0x6d6 },
548 { 0xb6d, 0xb6a, 0xdb6 },
549 { 0x76d, 0x6da, 0xbb6 },
550 { 0xedd, 0xdda, 0x76e },
551 { 0xddd, 0xbba, 0xeee },
552 { 0x7bb, 0xf7a, 0xdde },
553 { 0xf7b, 0xef6, 0x7de },
554 { 0xdf7, 0xbf6, 0xf7e },
555 { 0x7f7, 0xfee, 0xefe },
556 { 0xfdf, 0xfbe, 0x7fe },
557 { 0xf7f, 0xefe, 0xffe },
558 { 0xfff, 0xffe, 0xffd },
559};
560
561static int xr21v141x_set_baudrate(struct tty_struct *tty, struct usb_serial_port *port)
562{
563 u32 divisor, baud, idx;
564 u16 tx_mask, rx_mask;
565 int ret;
566
567 baud = tty->termios.c_ospeed;
568 if (!baud)
569 return 0;
570
571 baud = clamp(baud, XR21V141X_MIN_SPEED, XR21V141X_MAX_SPEED);
572 divisor = XR_INT_OSC_HZ / baud;
573 idx = ((32 * XR_INT_OSC_HZ) / baud) & 0x1f;
574 tx_mask = xr21v141x_txrx_clk_masks[idx].tx;
575
576 if (divisor & 0x01)
577 rx_mask = xr21v141x_txrx_clk_masks[idx].rx1;
578 else
579 rx_mask = xr21v141x_txrx_clk_masks[idx].rx0;
580
581 dev_dbg(&port->dev, "Setting baud rate: %u\n", baud);
582 /*
583 * XR21V141X uses fractional baud rate generator with 48MHz internal
584 * oscillator and 19-bit programmable divisor. So theoretically it can
585 * generate most commonly used baud rates with high accuracy.
586 */
587 ret = xr_set_reg_uart(port, XR21V141X_CLOCK_DIVISOR_0,
588 divisor & 0xff);
589 if (ret)
590 return ret;
591
592 ret = xr_set_reg_uart(port, XR21V141X_CLOCK_DIVISOR_1,
593 (divisor >> 8) & 0xff);
594 if (ret)
595 return ret;
596
597 ret = xr_set_reg_uart(port, XR21V141X_CLOCK_DIVISOR_2,
598 (divisor >> 16) & 0xff);
599 if (ret)
600 return ret;
601
602 ret = xr_set_reg_uart(port, XR21V141X_TX_CLOCK_MASK_0,
603 tx_mask & 0xff);
604 if (ret)
605 return ret;
606
607 ret = xr_set_reg_uart(port, XR21V141X_TX_CLOCK_MASK_1,
608 (tx_mask >> 8) & 0xff);
609 if (ret)
610 return ret;
611
612 ret = xr_set_reg_uart(port, XR21V141X_RX_CLOCK_MASK_0,
613 rx_mask & 0xff);
614 if (ret)
615 return ret;
616
617 ret = xr_set_reg_uart(port, XR21V141X_RX_CLOCK_MASK_1,
618 (rx_mask >> 8) & 0xff);
619 if (ret)
620 return ret;
621
622 tty_encode_baud_rate(tty, baud, baud);
623
624 return 0;
625}
626
627static void xr_set_flow_mode(struct tty_struct *tty,
628 struct usb_serial_port *port,
629 const struct ktermios *old_termios)
630{
631 struct xr_data *data = usb_get_serial_port_data(port);
632 const struct xr_type *type = data->type;
633 u16 flow, gpio_mode;
634 bool rs485_enabled;
635 int ret;
636
637 ret = xr_get_reg_uart(port, type->gpio_mode, &gpio_mode);
638 if (ret)
639 return;
640
641 /*
642 * According to the datasheets, the UART needs to be disabled while
643 * writing to the FLOW_CONTROL register (XR21V141X), or any register
644 * but GPIO_SET, GPIO_CLEAR, TX_BREAK and ERROR_STATUS (XR21B142X).
645 */
646 xr_uart_disable(port);
647
648 /* Set GPIO mode for controlling the pins manually by default. */
649 gpio_mode &= ~XR_GPIO_MODE_SEL_MASK;
650
651 rs485_enabled = !!(data->rs485.flags & SER_RS485_ENABLED);
652 if (rs485_enabled) {
653 dev_dbg(&port->dev, "Enabling RS-485\n");
654 gpio_mode |= XR_GPIO_MODE_SEL_RS485;
655 if (data->rs485.flags & SER_RS485_RTS_ON_SEND)
656 gpio_mode &= ~XR_GPIO_MODE_RS485_TX_H;
657 else
658 gpio_mode |= XR_GPIO_MODE_RS485_TX_H;
659 }
660
661 if (C_CRTSCTS(tty) && C_BAUD(tty) != B0 && !rs485_enabled) {
662 dev_dbg(&port->dev, "Enabling hardware flow ctrl\n");
663 gpio_mode |= XR_GPIO_MODE_SEL_RTS_CTS;
664 flow = XR_UART_FLOW_MODE_HW;
665 } else if (I_IXON(tty)) {
666 u8 start_char = START_CHAR(tty);
667 u8 stop_char = STOP_CHAR(tty);
668
669 dev_dbg(&port->dev, "Enabling sw flow ctrl\n");
670 flow = XR_UART_FLOW_MODE_SW;
671
672 xr_set_reg_uart(port, type->xon_char, start_char);
673 xr_set_reg_uart(port, type->xoff_char, stop_char);
674 } else {
675 dev_dbg(&port->dev, "Disabling flow ctrl\n");
676 flow = XR_UART_FLOW_MODE_NONE;
677 }
678
679 xr_set_reg_uart(port, type->flow_control, flow);
680 xr_set_reg_uart(port, type->gpio_mode, gpio_mode);
681
682 xr_uart_enable(port);
683
684 if (C_BAUD(tty) == B0)
685 xr_dtr_rts(port, 0);
686 else if (old_termios && (old_termios->c_cflag & CBAUD) == B0)
687 xr_dtr_rts(port, 1);
688}
689
690static void xr21v141x_set_line_settings(struct tty_struct *tty,
691 struct usb_serial_port *port,
692 const struct ktermios *old_termios)
693{
694 struct ktermios *termios = &tty->termios;
695 u8 bits = 0;
696 int ret;
697
698 if (!old_termios || (tty->termios.c_ospeed != old_termios->c_ospeed))
699 xr21v141x_set_baudrate(tty, port);
700
701 switch (C_CSIZE(tty)) {
702 case CS5:
703 case CS6:
704 /* CS5 and CS6 are not supported, so just restore old setting */
705 termios->c_cflag &= ~CSIZE;
706 if (old_termios)
707 termios->c_cflag |= old_termios->c_cflag & CSIZE;
708 else
709 termios->c_cflag |= CS8;
710
711 if (C_CSIZE(tty) == CS7)
712 bits |= XR_UART_DATA_7;
713 else
714 bits |= XR_UART_DATA_8;
715 break;
716 case CS7:
717 bits |= XR_UART_DATA_7;
718 break;
719 case CS8:
720 default:
721 bits |= XR_UART_DATA_8;
722 break;
723 }
724
725 if (C_PARENB(tty)) {
726 if (C_CMSPAR(tty)) {
727 if (C_PARODD(tty))
728 bits |= XR_UART_PARITY_MARK;
729 else
730 bits |= XR_UART_PARITY_SPACE;
731 } else {
732 if (C_PARODD(tty))
733 bits |= XR_UART_PARITY_ODD;
734 else
735 bits |= XR_UART_PARITY_EVEN;
736 }
737 }
738
739 if (C_CSTOPB(tty))
740 bits |= XR_UART_STOP_2;
741 else
742 bits |= XR_UART_STOP_1;
743
744 ret = xr_set_reg_uart(port, XR21V141X_REG_FORMAT, bits);
745 if (ret)
746 return;
747}
748
749static void xr_cdc_set_line_coding(struct tty_struct *tty,
750 struct usb_serial_port *port,
751 const struct ktermios *old_termios)
752{
753 struct xr_data *data = usb_get_serial_port_data(port);
754 struct usb_host_interface *alt = port->serial->interface->cur_altsetting;
755 struct usb_device *udev = port->serial->dev;
756 struct usb_cdc_line_coding *lc;
757 int ret;
758
759 lc = kzalloc(sizeof(*lc), GFP_KERNEL);
760 if (!lc)
761 return;
762
763 if (tty->termios.c_ospeed)
764 lc->dwDTERate = cpu_to_le32(tty->termios.c_ospeed);
765 else
766 lc->dwDTERate = cpu_to_le32(9600);
767
768 if (C_CSTOPB(tty))
769 lc->bCharFormat = USB_CDC_2_STOP_BITS;
770 else
771 lc->bCharFormat = USB_CDC_1_STOP_BITS;
772
773 if (C_PARENB(tty)) {
774 if (C_CMSPAR(tty)) {
775 if (C_PARODD(tty))
776 lc->bParityType = USB_CDC_MARK_PARITY;
777 else
778 lc->bParityType = USB_CDC_SPACE_PARITY;
779 } else {
780 if (C_PARODD(tty))
781 lc->bParityType = USB_CDC_ODD_PARITY;
782 else
783 lc->bParityType = USB_CDC_EVEN_PARITY;
784 }
785 } else {
786 lc->bParityType = USB_CDC_NO_PARITY;
787 }
788
789 if (!data->type->have_5_6_bit_mode &&
790 (C_CSIZE(tty) == CS5 || C_CSIZE(tty) == CS6)) {
791 tty->termios.c_cflag &= ~CSIZE;
792 if (old_termios)
793 tty->termios.c_cflag |= old_termios->c_cflag & CSIZE;
794 else
795 tty->termios.c_cflag |= CS8;
796 }
797
798 switch (C_CSIZE(tty)) {
799 case CS5:
800 lc->bDataBits = 5;
801 break;
802 case CS6:
803 lc->bDataBits = 6;
804 break;
805 case CS7:
806 lc->bDataBits = 7;
807 break;
808 case CS8:
809 default:
810 lc->bDataBits = 8;
811 break;
812 }
813
814 ret = usb_control_msg(udev, usb_sndctrlpipe(udev, 0),
815 USB_CDC_REQ_SET_LINE_CODING,
816 USB_TYPE_CLASS | USB_RECIP_INTERFACE,
817 0, alt->desc.bInterfaceNumber,
818 lc, sizeof(*lc), USB_CTRL_SET_TIMEOUT);
819 if (ret < 0)
820 dev_err(&port->dev, "Failed to set line coding: %d\n", ret);
821
822 kfree(lc);
823}
824
825static void xr_sanitize_serial_rs485(struct serial_rs485 *rs485)
826{
827 if (!(rs485->flags & SER_RS485_ENABLED)) {
828 memset(rs485, 0, sizeof(*rs485));
829 return;
830 }
831
832 /* RTS always toggles after TX */
833 if (rs485->flags & SER_RS485_RTS_ON_SEND)
834 rs485->flags &= ~SER_RS485_RTS_AFTER_SEND;
835 else
836 rs485->flags |= SER_RS485_RTS_AFTER_SEND;
837
838 /* Only the flags are implemented at the moment */
839 rs485->flags &= SER_RS485_ENABLED | SER_RS485_RTS_ON_SEND |
840 SER_RS485_RTS_AFTER_SEND;
841 rs485->delay_rts_before_send = 0;
842 rs485->delay_rts_after_send = 0;
843 memset(rs485->padding, 0, sizeof(rs485->padding));
844}
845
846static int xr_get_rs485_config(struct tty_struct *tty,
847 struct serial_rs485 __user *argp)
848{
849 struct usb_serial_port *port = tty->driver_data;
850 struct xr_data *data = usb_get_serial_port_data(port);
851
852 down_read(&tty->termios_rwsem);
853 if (copy_to_user(argp, &data->rs485, sizeof(data->rs485))) {
854 up_read(&tty->termios_rwsem);
855 return -EFAULT;
856 }
857 up_read(&tty->termios_rwsem);
858
859 return 0;
860}
861
862static int xr_set_rs485_config(struct tty_struct *tty,
863 struct serial_rs485 __user *argp)
864{
865 struct usb_serial_port *port = tty->driver_data;
866 struct xr_data *data = usb_get_serial_port_data(port);
867 struct serial_rs485 rs485;
868
869 if (copy_from_user(&rs485, argp, sizeof(rs485)))
870 return -EFAULT;
871 xr_sanitize_serial_rs485(&rs485);
872
873 down_write(&tty->termios_rwsem);
874 data->rs485 = rs485;
875 xr_set_flow_mode(tty, port, NULL);
876 up_write(&tty->termios_rwsem);
877
878 if (copy_to_user(argp, &rs485, sizeof(rs485)))
879 return -EFAULT;
880
881 return 0;
882}
883
884static int xr_ioctl(struct tty_struct *tty, unsigned int cmd, unsigned long arg)
885{
886 void __user *argp = (void __user *)arg;
887
888 switch (cmd) {
889 case TIOCGRS485:
890 return xr_get_rs485_config(tty, argp);
891 case TIOCSRS485:
892 return xr_set_rs485_config(tty, argp);
893 }
894
895 return -ENOIOCTLCMD;
896}
897
898static void xr_set_termios(struct tty_struct *tty,
899 struct usb_serial_port *port,
900 const struct ktermios *old_termios)
901{
902 struct xr_data *data = usb_get_serial_port_data(port);
903
904 /*
905 * XR21V141X does not have a CUSTOM_DRIVER flag and always enters CDC
906 * mode upon receiving CDC requests.
907 */
908 if (data->type->set_line_settings)
909 data->type->set_line_settings(tty, port, old_termios);
910 else
911 xr_cdc_set_line_coding(tty, port, old_termios);
912
913 xr_set_flow_mode(tty, port, old_termios);
914}
915
916static int xr_open(struct tty_struct *tty, struct usb_serial_port *port)
917{
918 int ret;
919
920 ret = xr_fifo_reset(port);
921 if (ret)
922 return ret;
923
924 ret = xr_uart_enable(port);
925 if (ret) {
926 dev_err(&port->dev, "Failed to enable UART\n");
927 return ret;
928 }
929
930 /* Setup termios */
931 if (tty)
932 xr_set_termios(tty, port, NULL);
933
934 ret = usb_serial_generic_open(tty, port);
935 if (ret) {
936 xr_uart_disable(port);
937 return ret;
938 }
939
940 return 0;
941}
942
943static void xr_close(struct usb_serial_port *port)
944{
945 usb_serial_generic_close(port);
946
947 xr_uart_disable(port);
948}
949
950static int xr_probe(struct usb_serial *serial, const struct usb_device_id *id)
951{
952 struct usb_interface *control = serial->interface;
953 struct usb_host_interface *alt = control->cur_altsetting;
954 struct usb_cdc_parsed_header hdrs;
955 struct usb_cdc_union_desc *desc;
956 struct usb_interface *data;
957 int ret;
958
959 ret = cdc_parse_cdc_header(&hdrs, control, alt->extra, alt->extralen);
960 if (ret < 0)
961 return -ENODEV;
962
963 desc = hdrs.usb_cdc_union_desc;
964 if (!desc)
965 return -ENODEV;
966
967 data = usb_ifnum_to_if(serial->dev, desc->bSlaveInterface0);
968 if (!data)
969 return -ENODEV;
970
971 ret = usb_serial_claim_interface(serial, data);
972 if (ret)
973 return ret;
974
975 usb_set_serial_data(serial, (void *)id->driver_info);
976
977 return 0;
978}
979
980static int xr_gpio_init(struct usb_serial_port *port, const struct xr_type *type)
981{
982 u16 mask, mode;
983 int ret;
984
985 /*
986 * Configure all pins as GPIO except for Receive and Transmit Toggle.
987 */
988 mode = 0;
989 if (type->have_xmit_toggle)
990 mode |= XR_GPIO_MODE_RX_TOGGLE | XR_GPIO_MODE_TX_TOGGLE;
991
992 ret = xr_set_reg_uart(port, type->gpio_mode, mode);
993 if (ret)
994 return ret;
995
996 /*
997 * Configure DTR and RTS as outputs and make sure they are deasserted
998 * (active low), and configure RI, CD, DSR and CTS as inputs.
999 */
1000 mask = XR_GPIO_DTR | XR_GPIO_RTS;
1001 ret = xr_set_reg_uart(port, type->gpio_direction, mask);
1002 if (ret)
1003 return ret;
1004
1005 ret = xr_set_reg_uart(port, type->gpio_set, mask);
1006 if (ret)
1007 return ret;
1008
1009 return 0;
1010}
1011
1012static int xr_port_probe(struct usb_serial_port *port)
1013{
1014 struct usb_interface_descriptor *desc;
1015 const struct xr_type *type;
1016 struct xr_data *data;
1017 enum xr_type_id type_id;
1018 int ret;
1019
1020 type_id = (int)(unsigned long)usb_get_serial_data(port->serial);
1021 type = &xr_types[type_id];
1022
1023 data = kzalloc(sizeof(*data), GFP_KERNEL);
1024 if (!data)
1025 return -ENOMEM;
1026
1027 data->type = type;
1028
1029 desc = &port->serial->interface->cur_altsetting->desc;
1030 if (type_id == XR21V141X)
1031 data->channel = desc->bInterfaceNumber / 2;
1032 else
1033 data->channel = desc->bInterfaceNumber;
1034
1035 usb_set_serial_port_data(port, data);
1036
1037 if (type->custom_driver) {
1038 ret = xr_set_reg_uart(port, type->custom_driver,
1039 XR_CUSTOM_DRIVER_ACTIVE);
1040 if (ret)
1041 goto err_free;
1042 }
1043
1044 ret = xr_gpio_init(port, type);
1045 if (ret)
1046 goto err_free;
1047
1048 return 0;
1049
1050err_free:
1051 kfree(data);
1052
1053 return ret;
1054}
1055
1056static void xr_port_remove(struct usb_serial_port *port)
1057{
1058 struct xr_data *data = usb_get_serial_port_data(port);
1059
1060 kfree(data);
1061}
1062
1063#define XR_DEVICE(vid, pid, type) \
1064 USB_DEVICE_INTERFACE_CLASS((vid), (pid), USB_CLASS_COMM), \
1065 .driver_info = (type)
1066
1067static const struct usb_device_id id_table[] = {
1068 { XR_DEVICE(0x04e2, 0x1400, XR2280X) },
1069 { XR_DEVICE(0x04e2, 0x1401, XR2280X) },
1070 { XR_DEVICE(0x04e2, 0x1402, XR2280X) },
1071 { XR_DEVICE(0x04e2, 0x1403, XR2280X) },
1072 { XR_DEVICE(0x04e2, 0x1410, XR21V141X) },
1073 { XR_DEVICE(0x04e2, 0x1411, XR21B1411) },
1074 { XR_DEVICE(0x04e2, 0x1412, XR21V141X) },
1075 { XR_DEVICE(0x04e2, 0x1414, XR21V141X) },
1076 { XR_DEVICE(0x04e2, 0x1420, XR21B142X) },
1077 { XR_DEVICE(0x04e2, 0x1422, XR21B142X) },
1078 { XR_DEVICE(0x04e2, 0x1424, XR21B142X) },
1079 { }
1080};
1081MODULE_DEVICE_TABLE(usb, id_table);
1082
1083static struct usb_serial_driver xr_device = {
1084 .driver = {
1085 .owner = THIS_MODULE,
1086 .name = "xr_serial",
1087 },
1088 .id_table = id_table,
1089 .num_ports = 1,
1090 .probe = xr_probe,
1091 .port_probe = xr_port_probe,
1092 .port_remove = xr_port_remove,
1093 .open = xr_open,
1094 .close = xr_close,
1095 .break_ctl = xr_break_ctl,
1096 .set_termios = xr_set_termios,
1097 .tiocmget = xr_tiocmget,
1098 .tiocmset = xr_tiocmset,
1099 .ioctl = xr_ioctl,
1100 .dtr_rts = xr_dtr_rts
1101};
1102
1103static struct usb_serial_driver * const serial_drivers[] = {
1104 &xr_device, NULL
1105};
1106
1107module_usb_serial_driver(serial_drivers, id_table);
1108
1109MODULE_AUTHOR("Manivannan Sadhasivam <mani@kernel.org>");
1110MODULE_DESCRIPTION("MaxLinear/Exar USB to Serial driver");
1111MODULE_LICENSE("GPL");