xref: /openbmc/linux/drivers/gpio/gpio-winbond.c (revision 9a29f5fc)
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  */
130 struct 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 
140 static struct winbond_gpio_params params;
141 
142 static 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, base);
152 	outb(WB_SIO_EXT_ENTER_KEY, base);
153 
154 	return 0;
155 }
156 
157 static void winbond_sio_select_logical(unsigned long base, u8 dev)
158 {
159 	outb(WB_SIO_REG_LOGICAL, base);
160 	outb(dev, base + 1);
161 }
162 
163 static void winbond_sio_leave(unsigned long base)
164 {
165 	outb(WB_SIO_EXT_EXIT_KEY, base);
166 
167 	release_region(base, 2);
168 }
169 
170 static void winbond_sio_reg_write(unsigned long base, u8 reg, u8 data)
171 {
172 	outb(reg, base);
173 	outb(data, base + 1);
174 }
175 
176 static u8 winbond_sio_reg_read(unsigned long base, u8 reg)
177 {
178 	outb(reg, base);
179 	return inb(base + 1);
180 }
181 
182 static 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, val);
189 }
190 
191 static 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, val);
198 }
199 
200 static 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  */
217 struct 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  */
239 struct 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 
251 static 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 */
351 static 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 
383 static 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(&offset, &info);
391 
392 	ret = winbond_sio_enter(*base);
393 	if (ret)
394 		return ret;
395 
396 	winbond_sio_select_logical(*base, info->dev);
397 
398 	val = winbond_sio_reg_btest(*base, info->datareg, offset);
399 	if (winbond_sio_reg_btest(*base, info->invreg, offset))
400 		val = !val;
401 
402 	winbond_sio_leave(*base);
403 
404 	return val;
405 }
406 
407 static 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(&offset, &info))
414 		return -EACCES;
415 
416 	ret = winbond_sio_enter(*base);
417 	if (ret)
418 		return ret;
419 
420 	winbond_sio_select_logical(*base, info->dev);
421 
422 	winbond_sio_reg_bset(*base, info->ioreg, offset);
423 
424 	winbond_sio_leave(*base);
425 
426 	return 0;
427 }
428 
429 static 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(&offset, &info))
438 		return -EACCES;
439 
440 	ret = winbond_sio_enter(*base);
441 	if (ret)
442 		return ret;
443 
444 	winbond_sio_select_logical(*base, info->dev);
445 
446 	winbond_sio_reg_bclear(*base, info->ioreg, offset);
447 
448 	if (winbond_sio_reg_btest(*base, info->invreg, offset))
449 		val = !val;
450 
451 	if (val)
452 		winbond_sio_reg_bset(*base, info->datareg, offset);
453 	else
454 		winbond_sio_reg_bclear(*base, info->datareg, offset);
455 
456 	winbond_sio_leave(*base);
457 
458 	return 0;
459 }
460 
461 static 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(&offset, &info))
468 		return;
469 
470 	if (winbond_sio_enter(*base) != 0)
471 		return;
472 
473 	winbond_sio_select_logical(*base, info->dev);
474 
475 	if (winbond_sio_reg_btest(*base, info->invreg, offset))
476 		val = !val;
477 
478 	if (val)
479 		winbond_sio_reg_bset(*base, info->datareg, offset);
480 	else
481 		winbond_sio_reg_bclear(*base, info->datareg, offset);
482 
483 	winbond_sio_leave(*base);
484 }
485 
486 static 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 
497 static 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, val);
512 }
513 
514 static 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 
522 static 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, conflict->dev);
531 
532 		if (winbond_sio_reg_btest(base, conflict->testreg,
533 					  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, info->dev);
552 
553 	winbond_sio_reg_bset(base, info->enablereg, info->enablebit);
554 
555 	if (params.ppgpios & BIT(idx))
556 		winbond_sio_reg_bset(base, info->outputreg,
557 				     info->outputppbit);
558 	else if (params.odgpios & BIT(idx))
559 		winbond_sio_reg_bclear(base, info->outputreg,
560 				       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 
571 static 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, 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 
587 static 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 
612 static 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(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(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(params.base) == 0;
646 }
647 
648 static 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(params.base);
656 	if (ret)
657 		return ret;
658 
659 	ret = winbond_gpio_configure(params.base);
660 
661 	winbond_sio_leave(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(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 
685 static 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 
693 module_isa_driver(winbond_gpio_idriver, 1);
694 
695 module_param_named(base, params.base, ulong, 0444);
696 MODULE_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 */
700 module_param_named(gpios, params.gpios, ulong, 0444);
701 MODULE_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  */
709 module_param_named(ppgpios, params.ppgpios, ulong, 0444);
710 MODULE_PARM_DESC(ppgpios,
711 		 "bitmask of GPIO ports to set to push-pull mode (bit 0 - GPIO1, bit 1 - GPIO2, etc.");
712 
713 module_param_named(odgpios, params.odgpios, ulong, 0444);
714 MODULE_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  */
723 module_param_named(pledgpio, params.pledgpio, bool, 0644);
724 MODULE_PARM_DESC(pledgpio,
725 		 "enable changing value of GPIO2.0 bit (Power LED), default no.");
726 
727 module_param_named(beepgpio, params.beepgpio, bool, 0644);
728 MODULE_PARM_DESC(beepgpio,
729 		 "enable changing value of GPIO2.1 bit (BEEP), default no.");
730 
731 MODULE_AUTHOR("Maciej S. Szmigiero <mail@maciej.szmigiero.name>");
732 MODULE_DESCRIPTION("GPIO interface for Winbond Super I/O chips");
733 MODULE_LICENSE("GPL");
734