1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * GPIO interface for Winbond Super I/O chips
4 * Currently, only W83627UHG (Nuvoton NCT6627UD) is supported.
5 *
6 * Author: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
7 */
8
9#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11#include <linux/gpio/driver.h>
12#include <linux/ioport.h>
13#include <linux/isa.h>
14#include <linux/module.h>
15
16#define WB_GPIO_DRIVER_NAME KBUILD_MODNAME
17
18#define WB_SIO_BASE 0x2e
19#define WB_SIO_BASE_HIGH 0x4e
20
21#define WB_SIO_EXT_ENTER_KEY 0x87
22#define WB_SIO_EXT_EXIT_KEY 0xaa
23
24/* global chip registers */
25
26#define WB_SIO_REG_LOGICAL 0x07
27
28#define WB_SIO_REG_CHIP_MSB 0x20
29#define WB_SIO_REG_CHIP_LSB 0x21
30
31#define WB_SIO_CHIP_ID_W83627UHG 0xa230
32#define WB_SIO_CHIP_ID_W83627UHG_MASK GENMASK(15, 4)
33
34#define WB_SIO_REG_DPD 0x22
35#define WB_SIO_REG_DPD_UARTA 4
36#define WB_SIO_REG_DPD_UARTB 5
37
38#define WB_SIO_REG_IDPD 0x23
39#define WB_SIO_REG_IDPD_UARTC 4
40#define WB_SIO_REG_IDPD_UARTD 5
41#define WB_SIO_REG_IDPD_UARTE 6
42#define WB_SIO_REG_IDPD_UARTF 7
43
44#define WB_SIO_REG_GLOBAL_OPT 0x24
45#define WB_SIO_REG_GO_ENFDC 1
46
47#define WB_SIO_REG_OVTGPIO3456 0x29
48#define WB_SIO_REG_OG3456_G3PP 3
49#define WB_SIO_REG_OG3456_G4PP 4
50#define WB_SIO_REG_OG3456_G5PP 5
51#define WB_SIO_REG_OG3456_G6PP 7
52
53#define WB_SIO_REG_I2C_PS 0x2a
54#define WB_SIO_REG_I2CPS_I2CFS 1
55
56#define WB_SIO_REG_GPIO1_MF 0x2c
57#define WB_SIO_REG_G1MF_G1PP 6
58#define WB_SIO_REG_G1MF_G2PP 7
59#define WB_SIO_REG_G1MF_FS_MASK GENMASK(1, 0)
60#define WB_SIO_REG_G1MF_FS_IR_OFF 0
61#define WB_SIO_REG_G1MF_FS_IR 1
62#define WB_SIO_REG_G1MF_FS_GPIO1 2
63#define WB_SIO_REG_G1MF_FS_UARTB 3
64
65/* not an actual device number, just a value meaning 'no device' */
66#define WB_SIO_DEV_NONE 0xff
67
68/* registers with offsets >= 0x30 are specific for a particular device */
69
70/* UART B logical device */
71#define WB_SIO_DEV_UARTB 0x03
72#define WB_SIO_UARTB_REG_ENABLE 0x30
73#define WB_SIO_UARTB_ENABLE_ON 0
74
75/* UART C logical device */
76#define WB_SIO_DEV_UARTC 0x06
77#define WB_SIO_UARTC_REG_ENABLE 0x30
78#define WB_SIO_UARTC_ENABLE_ON 0
79
80/* GPIO3, GPIO4 logical device */
81#define WB_SIO_DEV_GPIO34 0x07
82#define WB_SIO_GPIO34_REG_ENABLE 0x30
83#define WB_SIO_GPIO34_ENABLE_3 0
84#define WB_SIO_GPIO34_ENABLE_4 1
85#define WB_SIO_GPIO34_REG_IO3 0xe0
86#define WB_SIO_GPIO34_REG_DATA3 0xe1
87#define WB_SIO_GPIO34_REG_INV3 0xe2
88#define WB_SIO_GPIO34_REG_IO4 0xe4
89#define WB_SIO_GPIO34_REG_DATA4 0xe5
90#define WB_SIO_GPIO34_REG_INV4 0xe6
91
92/* WDTO, PLED, GPIO5, GPIO6 logical device */
93#define WB_SIO_DEV_WDGPIO56 0x08
94#define WB_SIO_WDGPIO56_REG_ENABLE 0x30
95#define WB_SIO_WDGPIO56_ENABLE_5 1
96#define WB_SIO_WDGPIO56_ENABLE_6 2
97#define WB_SIO_WDGPIO56_REG_IO5 0xe0
98#define WB_SIO_WDGPIO56_REG_DATA5 0xe1
99#define WB_SIO_WDGPIO56_REG_INV5 0xe2
100#define WB_SIO_WDGPIO56_REG_IO6 0xe4
101#define WB_SIO_WDGPIO56_REG_DATA6 0xe5
102#define WB_SIO_WDGPIO56_REG_INV6 0xe6
103
104/* GPIO1, GPIO2, SUSLED logical device */
105#define WB_SIO_DEV_GPIO12 0x09
106#define WB_SIO_GPIO12_REG_ENABLE 0x30
107#define WB_SIO_GPIO12_ENABLE_1 0
108#define WB_SIO_GPIO12_ENABLE_2 1
109#define WB_SIO_GPIO12_REG_IO1 0xe0
110#define WB_SIO_GPIO12_REG_DATA1 0xe1
111#define WB_SIO_GPIO12_REG_INV1 0xe2
112#define WB_SIO_GPIO12_REG_IO2 0xe4
113#define WB_SIO_GPIO12_REG_DATA2 0xe5
114#define WB_SIO_GPIO12_REG_INV2 0xe6
115
116/* UART D logical device */
117#define WB_SIO_DEV_UARTD 0x0d
118#define WB_SIO_UARTD_REG_ENABLE 0x30
119#define WB_SIO_UARTD_ENABLE_ON 0
120
121/* UART E logical device */
122#define WB_SIO_DEV_UARTE 0x0e
123#define WB_SIO_UARTE_REG_ENABLE 0x30
124#define WB_SIO_UARTE_ENABLE_ON 0
125
126/*
127 * for a description what a particular field of this struct means please see
128 * a description of the relevant module parameter at the bottom of this file
129 */
130struct winbond_gpio_params {
131 unsigned long base;
132 unsigned long gpios;
133 unsigned long ppgpios;
134 unsigned long odgpios;
135 bool pledgpio;
136 bool beepgpio;
137 bool i2cgpio;
138};
139
140static struct winbond_gpio_params params;
141
142static int winbond_sio_enter(unsigned long base)
143{
144 if (!request_muxed_region(base, 2, WB_GPIO_DRIVER_NAME))
145 return -EBUSY;
146
147 /*
148 * datasheet says two successive writes of the "key" value are needed
149 * in order for chip to enter the "Extended Function Mode"
150 */
151 outb(WB_SIO_EXT_ENTER_KEY, port: base);
152 outb(WB_SIO_EXT_ENTER_KEY, port: base);
153
154 return 0;
155}
156
157static void winbond_sio_select_logical(unsigned long base, u8 dev)
158{
159 outb(WB_SIO_REG_LOGICAL, port: base);
160 outb(value: dev, port: base + 1);
161}
162
163static void winbond_sio_leave(unsigned long base)
164{
165 outb(WB_SIO_EXT_EXIT_KEY, port: base);
166
167 release_region(base, 2);
168}
169
170static void winbond_sio_reg_write(unsigned long base, u8 reg, u8 data)
171{
172 outb(value: reg, port: base);
173 outb(value: data, port: base + 1);
174}
175
176static u8 winbond_sio_reg_read(unsigned long base, u8 reg)
177{
178 outb(value: reg, port: base);
179 return inb(port: base + 1);
180}
181
182static void winbond_sio_reg_bset(unsigned long base, u8 reg, u8 bit)
183{
184 u8 val;
185
186 val = winbond_sio_reg_read(base, reg);
187 val |= BIT(bit);
188 winbond_sio_reg_write(base, reg, data: val);
189}
190
191static void winbond_sio_reg_bclear(unsigned long base, u8 reg, u8 bit)
192{
193 u8 val;
194
195 val = winbond_sio_reg_read(base, reg);
196 val &= ~BIT(bit);
197 winbond_sio_reg_write(base, reg, data: val);
198}
199
200static bool winbond_sio_reg_btest(unsigned long base, u8 reg, u8 bit)
201{
202 return winbond_sio_reg_read(base, reg) & BIT(bit);
203}
204
205/**
206 * struct winbond_gpio_port_conflict - possibly conflicting device information
207 * @name: device name (NULL means no conflicting device defined)
208 * @dev: Super I/O logical device number where the testreg register
209 * is located (or WB_SIO_DEV_NONE - don't select any
210 * logical device)
211 * @testreg: register number where the testbit bit is located
212 * @testbit: index of a bit to check whether an actual conflict exists
213 * @warnonly: if set then a conflict isn't fatal (just warn about it),
214 * otherwise disable the particular GPIO port if a conflict
215 * is detected
216 */
217struct winbond_gpio_port_conflict {
218 const char *name;
219 u8 dev;
220 u8 testreg;
221 u8 testbit;
222 bool warnonly;
223};
224
225/**
226 * struct winbond_gpio_info - information about a particular GPIO port (device)
227 * @dev: Super I/O logical device number of the registers
228 * specified below
229 * @enablereg: port enable bit register number
230 * @enablebit: index of a port enable bit
231 * @outputreg: output driver mode bit register number
232 * @outputppbit: index of a push-pull output driver mode bit
233 * @ioreg: data direction register number
234 * @invreg: pin data inversion register number
235 * @datareg: pin data register number
236 * @conflict: description of a device that possibly conflicts with
237 * this port
238 */
239struct winbond_gpio_info {
240 u8 dev;
241 u8 enablereg;
242 u8 enablebit;
243 u8 outputreg;
244 u8 outputppbit;
245 u8 ioreg;
246 u8 invreg;
247 u8 datareg;
248 struct winbond_gpio_port_conflict conflict;
249};
250
251static const struct winbond_gpio_info winbond_gpio_infos[6] = {
252 { /* 0 */
253 .dev = WB_SIO_DEV_GPIO12,
254 .enablereg = WB_SIO_GPIO12_REG_ENABLE,
255 .enablebit = WB_SIO_GPIO12_ENABLE_1,
256 .outputreg = WB_SIO_REG_GPIO1_MF,
257 .outputppbit = WB_SIO_REG_G1MF_G1PP,
258 .ioreg = WB_SIO_GPIO12_REG_IO1,
259 .invreg = WB_SIO_GPIO12_REG_INV1,
260 .datareg = WB_SIO_GPIO12_REG_DATA1,
261 .conflict = {
262 .name = "UARTB",
263 .dev = WB_SIO_DEV_UARTB,
264 .testreg = WB_SIO_UARTB_REG_ENABLE,
265 .testbit = WB_SIO_UARTB_ENABLE_ON,
266 .warnonly = true
267 }
268 },
269 { /* 1 */
270 .dev = WB_SIO_DEV_GPIO12,
271 .enablereg = WB_SIO_GPIO12_REG_ENABLE,
272 .enablebit = WB_SIO_GPIO12_ENABLE_2,
273 .outputreg = WB_SIO_REG_GPIO1_MF,
274 .outputppbit = WB_SIO_REG_G1MF_G2PP,
275 .ioreg = WB_SIO_GPIO12_REG_IO2,
276 .invreg = WB_SIO_GPIO12_REG_INV2,
277 .datareg = WB_SIO_GPIO12_REG_DATA2
278 /* special conflict handling so doesn't use conflict data */
279 },
280 { /* 2 */
281 .dev = WB_SIO_DEV_GPIO34,
282 .enablereg = WB_SIO_GPIO34_REG_ENABLE,
283 .enablebit = WB_SIO_GPIO34_ENABLE_3,
284 .outputreg = WB_SIO_REG_OVTGPIO3456,
285 .outputppbit = WB_SIO_REG_OG3456_G3PP,
286 .ioreg = WB_SIO_GPIO34_REG_IO3,
287 .invreg = WB_SIO_GPIO34_REG_INV3,
288 .datareg = WB_SIO_GPIO34_REG_DATA3,
289 .conflict = {
290 .name = "UARTC",
291 .dev = WB_SIO_DEV_UARTC,
292 .testreg = WB_SIO_UARTC_REG_ENABLE,
293 .testbit = WB_SIO_UARTC_ENABLE_ON,
294 .warnonly = true
295 }
296 },
297 { /* 3 */
298 .dev = WB_SIO_DEV_GPIO34,
299 .enablereg = WB_SIO_GPIO34_REG_ENABLE,
300 .enablebit = WB_SIO_GPIO34_ENABLE_4,
301 .outputreg = WB_SIO_REG_OVTGPIO3456,
302 .outputppbit = WB_SIO_REG_OG3456_G4PP,
303 .ioreg = WB_SIO_GPIO34_REG_IO4,
304 .invreg = WB_SIO_GPIO34_REG_INV4,
305 .datareg = WB_SIO_GPIO34_REG_DATA4,
306 .conflict = {
307 .name = "UARTD",
308 .dev = WB_SIO_DEV_UARTD,
309 .testreg = WB_SIO_UARTD_REG_ENABLE,
310 .testbit = WB_SIO_UARTD_ENABLE_ON,
311 .warnonly = true
312 }
313 },
314 { /* 4 */
315 .dev = WB_SIO_DEV_WDGPIO56,
316 .enablereg = WB_SIO_WDGPIO56_REG_ENABLE,
317 .enablebit = WB_SIO_WDGPIO56_ENABLE_5,
318 .outputreg = WB_SIO_REG_OVTGPIO3456,
319 .outputppbit = WB_SIO_REG_OG3456_G5PP,
320 .ioreg = WB_SIO_WDGPIO56_REG_IO5,
321 .invreg = WB_SIO_WDGPIO56_REG_INV5,
322 .datareg = WB_SIO_WDGPIO56_REG_DATA5,
323 .conflict = {
324 .name = "UARTE",
325 .dev = WB_SIO_DEV_UARTE,
326 .testreg = WB_SIO_UARTE_REG_ENABLE,
327 .testbit = WB_SIO_UARTE_ENABLE_ON,
328 .warnonly = true
329 }
330 },
331 { /* 5 */
332 .dev = WB_SIO_DEV_WDGPIO56,
333 .enablereg = WB_SIO_WDGPIO56_REG_ENABLE,
334 .enablebit = WB_SIO_WDGPIO56_ENABLE_6,
335 .outputreg = WB_SIO_REG_OVTGPIO3456,
336 .outputppbit = WB_SIO_REG_OG3456_G6PP,
337 .ioreg = WB_SIO_WDGPIO56_REG_IO6,
338 .invreg = WB_SIO_WDGPIO56_REG_INV6,
339 .datareg = WB_SIO_WDGPIO56_REG_DATA6,
340 .conflict = {
341 .name = "FDC",
342 .dev = WB_SIO_DEV_NONE,
343 .testreg = WB_SIO_REG_GLOBAL_OPT,
344 .testbit = WB_SIO_REG_GO_ENFDC,
345 .warnonly = false
346 }
347 }
348};
349
350/* returns whether changing a pin is allowed */
351static bool winbond_gpio_get_info(unsigned int *gpio_num,
352 const struct winbond_gpio_info **info)
353{
354 bool allow_changing = true;
355 unsigned long i;
356
357 for_each_set_bit(i, &params.gpios, BITS_PER_LONG) {
358 if (*gpio_num < 8)
359 break;
360
361 *gpio_num -= 8;
362 }
363
364 *info = &winbond_gpio_infos[i];
365
366 /*
367 * GPIO2 (the second port) shares some pins with a basic PC
368 * functionality, which is very likely controlled by the firmware.
369 * Don't allow changing these pins by default.
370 */
371 if (i == 1) {
372 if (*gpio_num == 0 && !params.pledgpio)
373 allow_changing = false;
374 else if (*gpio_num == 1 && !params.beepgpio)
375 allow_changing = false;
376 else if ((*gpio_num == 5 || *gpio_num == 6) && !params.i2cgpio)
377 allow_changing = false;
378 }
379
380 return allow_changing;
381}
382
383static int winbond_gpio_get(struct gpio_chip *gc, unsigned int offset)
384{
385 unsigned long *base = gpiochip_get_data(gc);
386 const struct winbond_gpio_info *info;
387 bool val;
388 int ret;
389
390 winbond_gpio_get_info(gpio_num: &offset, info: &info);
391
392 ret = winbond_sio_enter(base: *base);
393 if (ret)
394 return ret;
395
396 winbond_sio_select_logical(base: *base, dev: info->dev);
397
398 val = winbond_sio_reg_btest(base: *base, reg: info->datareg, bit: offset);
399 if (winbond_sio_reg_btest(base: *base, reg: info->invreg, bit: offset))
400 val = !val;
401
402 winbond_sio_leave(base: *base);
403
404 return val;
405}
406
407static int winbond_gpio_direction_in(struct gpio_chip *gc, unsigned int offset)
408{
409 unsigned long *base = gpiochip_get_data(gc);
410 const struct winbond_gpio_info *info;
411 int ret;
412
413 if (!winbond_gpio_get_info(gpio_num: &offset, info: &info))
414 return -EACCES;
415
416 ret = winbond_sio_enter(base: *base);
417 if (ret)
418 return ret;
419
420 winbond_sio_select_logical(base: *base, dev: info->dev);
421
422 winbond_sio_reg_bset(base: *base, reg: info->ioreg, bit: offset);
423
424 winbond_sio_leave(base: *base);
425
426 return 0;
427}
428
429static int winbond_gpio_direction_out(struct gpio_chip *gc,
430 unsigned int offset,
431 int val)
432{
433 unsigned long *base = gpiochip_get_data(gc);
434 const struct winbond_gpio_info *info;
435 int ret;
436
437 if (!winbond_gpio_get_info(gpio_num: &offset, info: &info))
438 return -EACCES;
439
440 ret = winbond_sio_enter(base: *base);
441 if (ret)
442 return ret;
443
444 winbond_sio_select_logical(base: *base, dev: info->dev);
445
446 winbond_sio_reg_bclear(base: *base, reg: info->ioreg, bit: offset);
447
448 if (winbond_sio_reg_btest(base: *base, reg: info->invreg, bit: offset))
449 val = !val;
450
451 if (val)
452 winbond_sio_reg_bset(base: *base, reg: info->datareg, bit: offset);
453 else
454 winbond_sio_reg_bclear(base: *base, reg: info->datareg, bit: offset);
455
456 winbond_sio_leave(base: *base);
457
458 return 0;
459}
460
461static void winbond_gpio_set(struct gpio_chip *gc, unsigned int offset,
462 int val)
463{
464 unsigned long *base = gpiochip_get_data(gc);
465 const struct winbond_gpio_info *info;
466
467 if (!winbond_gpio_get_info(gpio_num: &offset, info: &info))
468 return;
469
470 if (winbond_sio_enter(base: *base) != 0)
471 return;
472
473 winbond_sio_select_logical(base: *base, dev: info->dev);
474
475 if (winbond_sio_reg_btest(base: *base, reg: info->invreg, bit: offset))
476 val = !val;
477
478 if (val)
479 winbond_sio_reg_bset(base: *base, reg: info->datareg, bit: offset);
480 else
481 winbond_sio_reg_bclear(base: *base, reg: info->datareg, bit: offset);
482
483 winbond_sio_leave(base: *base);
484}
485
486static struct gpio_chip winbond_gpio_chip = {
487 .base = -1,
488 .label = WB_GPIO_DRIVER_NAME,
489 .owner = THIS_MODULE,
490 .can_sleep = true,
491 .get = winbond_gpio_get,
492 .direction_input = winbond_gpio_direction_in,
493 .set = winbond_gpio_set,
494 .direction_output = winbond_gpio_direction_out,
495};
496
497static void winbond_gpio_configure_port0_pins(unsigned long base)
498{
499 unsigned int val;
500
501 val = winbond_sio_reg_read(base, WB_SIO_REG_GPIO1_MF);
502 if ((val & WB_SIO_REG_G1MF_FS_MASK) == WB_SIO_REG_G1MF_FS_GPIO1)
503 return;
504
505 pr_warn("GPIO1 pins were connected to something else (%.2x), fixing\n",
506 val);
507
508 val &= ~WB_SIO_REG_G1MF_FS_MASK;
509 val |= WB_SIO_REG_G1MF_FS_GPIO1;
510
511 winbond_sio_reg_write(base, WB_SIO_REG_GPIO1_MF, data: val);
512}
513
514static void winbond_gpio_configure_port1_check_i2c(unsigned long base)
515{
516 params.i2cgpio = !winbond_sio_reg_btest(base, WB_SIO_REG_I2C_PS,
517 WB_SIO_REG_I2CPS_I2CFS);
518 if (!params.i2cgpio)
519 pr_warn("disabling GPIO2.5 and GPIO2.6 as I2C is enabled\n");
520}
521
522static bool winbond_gpio_configure_port(unsigned long base, unsigned int idx)
523{
524 const struct winbond_gpio_info *info = &winbond_gpio_infos[idx];
525 const struct winbond_gpio_port_conflict *conflict = &info->conflict;
526
527 /* is there a possible conflicting device defined? */
528 if (conflict->name != NULL) {
529 if (conflict->dev != WB_SIO_DEV_NONE)
530 winbond_sio_select_logical(base, dev: conflict->dev);
531
532 if (winbond_sio_reg_btest(base, reg: conflict->testreg,
533 bit: conflict->testbit)) {
534 if (conflict->warnonly)
535 pr_warn("enabled GPIO%u share pins with active %s\n",
536 idx + 1, conflict->name);
537 else {
538 pr_warn("disabling GPIO%u as %s is enabled\n",
539 idx + 1, conflict->name);
540 return false;
541 }
542 }
543 }
544
545 /* GPIO1 and GPIO2 need some (additional) special handling */
546 if (idx == 0)
547 winbond_gpio_configure_port0_pins(base);
548 else if (idx == 1)
549 winbond_gpio_configure_port1_check_i2c(base);
550
551 winbond_sio_select_logical(base, dev: info->dev);
552
553 winbond_sio_reg_bset(base, reg: info->enablereg, bit: info->enablebit);
554
555 if (params.ppgpios & BIT(idx))
556 winbond_sio_reg_bset(base, reg: info->outputreg,
557 bit: info->outputppbit);
558 else if (params.odgpios & BIT(idx))
559 winbond_sio_reg_bclear(base, reg: info->outputreg,
560 bit: info->outputppbit);
561 else
562 pr_notice("GPIO%u pins are %s\n", idx + 1,
563 winbond_sio_reg_btest(base, info->outputreg,
564 info->outputppbit) ?
565 "push-pull" :
566 "open drain");
567
568 return true;
569}
570
571static int winbond_gpio_configure(unsigned long base)
572{
573 unsigned long i;
574
575 for_each_set_bit(i, &params.gpios, BITS_PER_LONG)
576 if (!winbond_gpio_configure_port(base, idx: i))
577 __clear_bit(i, &params.gpios);
578
579 if (!params.gpios) {
580 pr_err("please use 'gpios' module parameter to select some active GPIO ports to enable\n");
581 return -EINVAL;
582 }
583
584 return 0;
585}
586
587static int winbond_gpio_check_chip(unsigned long base)
588{
589 int ret;
590 unsigned int chip;
591
592 ret = winbond_sio_enter(base);
593 if (ret)
594 return ret;
595
596 chip = winbond_sio_reg_read(base, WB_SIO_REG_CHIP_MSB) << 8;
597 chip |= winbond_sio_reg_read(base, WB_SIO_REG_CHIP_LSB);
598
599 pr_notice("chip ID at %lx is %.4x\n", base, chip);
600
601 if ((chip & WB_SIO_CHIP_ID_W83627UHG_MASK) !=
602 WB_SIO_CHIP_ID_W83627UHG) {
603 pr_err("not an our chip\n");
604 ret = -ENODEV;
605 }
606
607 winbond_sio_leave(base);
608
609 return ret;
610}
611
612static int winbond_gpio_imatch(struct device *dev, unsigned int id)
613{
614 unsigned long gpios_rem;
615 int ret;
616
617 gpios_rem = params.gpios & ~GENMASK(ARRAY_SIZE(winbond_gpio_infos) - 1,
618 0);
619 if (gpios_rem) {
620 pr_warn("unknown ports (%lx) enabled in GPIO ports bitmask\n",
621 gpios_rem);
622 params.gpios &= ~gpios_rem;
623 }
624
625 if (params.ppgpios & params.odgpios) {
626 pr_err("some GPIO ports are set both to push-pull and open drain mode at the same time\n");
627 return 0;
628 }
629
630 if (params.base != 0)
631 return winbond_gpio_check_chip(base: params.base) == 0;
632
633 /*
634 * if the 'base' module parameter is unset probe two chip default
635 * I/O port bases
636 */
637 params.base = WB_SIO_BASE;
638 ret = winbond_gpio_check_chip(base: params.base);
639 if (ret == 0)
640 return 1;
641 if (ret != -ENODEV && ret != -EBUSY)
642 return 0;
643
644 params.base = WB_SIO_BASE_HIGH;
645 return winbond_gpio_check_chip(base: params.base) == 0;
646}
647
648static int winbond_gpio_iprobe(struct device *dev, unsigned int id)
649{
650 int ret;
651
652 if (params.base == 0)
653 return -EINVAL;
654
655 ret = winbond_sio_enter(base: params.base);
656 if (ret)
657 return ret;
658
659 ret = winbond_gpio_configure(base: params.base);
660
661 winbond_sio_leave(base: params.base);
662
663 if (ret)
664 return ret;
665
666 /*
667 * Add 8 gpios for every GPIO port that was enabled in gpios
668 * module parameter (that wasn't disabled earlier in
669 * winbond_gpio_configure() & co. due to, for example, a pin conflict).
670 */
671 winbond_gpio_chip.ngpio = hweight_long(w: params.gpios) * 8;
672
673 /*
674 * GPIO6 port has only 5 pins, so if it is enabled we have to adjust
675 * the total count appropriately
676 */
677 if (params.gpios & BIT(5))
678 winbond_gpio_chip.ngpio -= (8 - 5);
679
680 winbond_gpio_chip.parent = dev;
681
682 return devm_gpiochip_add_data(dev, &winbond_gpio_chip, &params.base);
683}
684
685static struct isa_driver winbond_gpio_idriver = {
686 .driver = {
687 .name = WB_GPIO_DRIVER_NAME,
688 },
689 .match = winbond_gpio_imatch,
690 .probe = winbond_gpio_iprobe,
691};
692
693module_isa_driver(winbond_gpio_idriver, 1);
694
695module_param_named(base, params.base, ulong, 0444);
696MODULE_PARM_DESC(base,
697 "I/O port base (when unset - probe chip default ones)");
698
699/* This parameter sets which GPIO devices (ports) we enable */
700module_param_named(gpios, params.gpios, ulong, 0444);
701MODULE_PARM_DESC(gpios,
702 "bitmask of GPIO ports to enable (bit 0 - GPIO1, bit 1 - GPIO2, etc.");
703
704/*
705 * These two parameters below set how we configure GPIO ports output drivers.
706 * It can't be a one bitmask since we need three values per port: push-pull,
707 * open-drain and keep as-is (this is the default).
708 */
709module_param_named(ppgpios, params.ppgpios, ulong, 0444);
710MODULE_PARM_DESC(ppgpios,
711 "bitmask of GPIO ports to set to push-pull mode (bit 0 - GPIO1, bit 1 - GPIO2, etc.");
712
713module_param_named(odgpios, params.odgpios, ulong, 0444);
714MODULE_PARM_DESC(odgpios,
715 "bitmask of GPIO ports to set to open drain mode (bit 0 - GPIO1, bit 1 - GPIO2, etc.");
716
717/*
718 * GPIO2.0 and GPIO2.1 control a basic PC functionality that we
719 * don't allow tinkering with by default (it is very likely that the
720 * firmware owns these pins).
721 * These two parameters below allow overriding these prohibitions.
722 */
723module_param_named(pledgpio, params.pledgpio, bool, 0644);
724MODULE_PARM_DESC(pledgpio,
725 "enable changing value of GPIO2.0 bit (Power LED), default no.");
726
727module_param_named(beepgpio, params.beepgpio, bool, 0644);
728MODULE_PARM_DESC(beepgpio,
729 "enable changing value of GPIO2.1 bit (BEEP), default no.");
730
731MODULE_AUTHOR("Maciej S. Szmigiero <mail@maciej.szmigiero.name>");
732MODULE_DESCRIPTION("GPIO interface for Winbond Super I/O chips");
733MODULE_LICENSE("GPL");
734

source code of linux/drivers/gpio/gpio-winbond.c