xref: /netbsd-src/sys/dev/isa/nct.c (revision c7fb772b85b2b5d4cfb282f868f454b4701534fd)
1 /*	$NetBSD: nct.c,v 1.5 2021/08/07 16:19:12 thorpej Exp $	*/
2 
3 /*-
4  * Copyright (c) 2019, 2020 The NetBSD Foundation, Inc.
5  * All rights reserved.
6  *
7  * This code is derived from software contributed to The NetBSD Foundation
8  * by Andrew Doran.
9  *
10  * Redistribution and use in source and binary forms, with or without
11  * modification, are permitted provided that the following conditions
12  * are met:
13  * 1. Redistributions of source code must retain the above copyright
14  *    notice, this list of conditions and the following disclaimer.
15  * 2. Redistributions in binary form must reproduce the above copyright
16  *    notice, this list of conditions and the following disclaimer in the
17  *    documentation and/or other materials provided with the distribution.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29  * POSSIBILITY OF SUCH DAMAGE.
30  */
31 
32 /*
33  * Nuvoton NCT5104D
34  *
35  * - GPIO: full support.
36  * - Watchdog: no support.  Watchdog uses GPIO pins.
37  * - UARTS: handled by com driver.  3rd & 4th UARTs use GPIO pins.
38  *
39  * If asked to probe with a wildcard address, we'll only do so if known to
40  * be running on a PC Engines system.  Probe is invasive.
41  *
42  * Register access on Super I/O chips typically involves one or two levels
43  * of indirection, so we try hard to avoid needless register access.
44  */
45 
46 #include <sys/cdefs.h>
47 __KERNEL_RCSID(0, "$NetBSD: nct.c,v 1.5 2021/08/07 16:19:12 thorpej Exp $");
48 
49 #include <sys/param.h>
50 #include <sys/systm.h>
51 #include <sys/types.h>
52 #include <sys/device.h>
53 #include <sys/module.h>
54 #include <sys/bus.h>
55 #include <sys/gpio.h>
56 
57 #include <machine/autoconf.h>
58 
59 #include <dev/isa/isavar.h>
60 
61 #include <dev/gpio/gpiovar.h>
62 
63 /*
64  * Hardware interface definition (enough for GPIO only).
65  */
66 
67 /* I/O basics */
68 #define	NCT_IOBASE_A		0x2e
69 #define	NCT_IOBASE_B		0x4e
70 #define	NCT_IOSIZE		2
71 #define	NCT_CHIP_ID_1		0x1061
72 #define	NCT_CHIP_ID_2		0xc452	/* PC Engines APU */
73 #define	NCT_NUM_PINS		17
74 
75 /* Enable/disable keys */
76 #define NCT_KEY_UNLOCK		0x87
77 #define NCT_KEY_LOCK		0xaa
78 
79 /* I/O ports */
80 #define	NCT_PORT_SELECT		0
81 #define	NCT_PORT_DATA		1
82 
83 /* Global registers */
84 #define	GD_DEVSEL		0x0007	/* logical device select */
85 #define	GD_MULTIFUN		0x001c	/* multi function selection */
86 #define		GD_MULTIFUN_GPIO1	0x04	/* clr: gpio1 available */
87 #define		GD_MULTIFUN_GPIO0	0x08	/* clr: gpio0 available */
88 #define		GD_MULTIFUN_GPIO67	0x10	/* set: gpio67 available */
89 #define	GD_GLOBOPT		0x0027	/* global option */
90 #define 	GD_GLOBOPT_GPIO67	0x04	/* clr: gpio67 available */
91 #define	GD_ID_HIGH		0x0020	/* ID high byte */
92 #define	GD_ID_LOW		0x0021	/* ID low byte */
93 
94 /* Logical device 7 */
95 #define	LD7_ENABLE		0x0730	/* GPIO function enable */
96 #define		LD7_ENABLE_GPIO0	0x01
97 #define		LD7_ENABLE_GPIO1	0x02
98 #define		LD7_ENABLE_GPIO67	0x40
99 #define	LD7_GPIO0_DIRECTION	0x07e0	/* clr for output, set for input */
100 #define	LD7_GPIO0_DATA		0x07e1	/* current status */
101 #define	LD7_GPIO0_INVERSION	0x07e2	/* set to invert i/o */
102 #define	LD7_GPIO0_STATUS	0x07e3	/* edge detect, reading clears */
103 #define	LD7_GPIO1_DIRECTION	0x07e4	/* clr for output, set for input */
104 #define	LD7_GPIO1_DATA		0x07e5	/* current status */
105 #define	LD7_GPIO1_INVERSION	0x07e6	/* set to invert i/o */
106 #define	LD7_GPIO1_STATUS	0x07e7	/* edge detect, reading clears */
107 #define	LD7_GPIO67_DIRECTION	0x07f8	/* clr for output, set for input */
108 #define	LD7_GPIO67_DATA		0x07f9	/* current status */
109 #define	LD7_GPIO67_INVERSION	0x07fa	/* set to invert i/o */
110 #define	LD7_GPIO67_STATUS	0x07fb	/* edge detect, reading clears */
111 
112 /* Logical device 8 */
113 #define	LD8_DEVCFG		0x0830	/* WDT/GPIO device config */
114 #define	LD8_GPIO0_MULTIFUNC	0x08e0	/* clr: gpio, set: pin unusable */
115 #define	LD8_GPIO1_MULTIFUNC	0x08e1	/* clr: gpio, set: pin unusable */
116 #define	LD8_GPIO67_MULTIFUNC	0x08e7	/* clr: gpio, set: pin unusable */
117 
118 /* Logical device 10 */
119 #define	LDA_UARTC_ENABLE	0x0a30	/* bit 0: UARTC active */
120 
121 /* Logical device 11 */
122 #define	LDB_UARTD_ENABLE	0x0b30	/* bit 0: UARTD active */
123 
124 /* Logical device 15 */
125 #define	LDF_GPIO0_OUTMODE	0x0fe0	/* clr: push/pull, set: open drain */
126 #define	LDF_GPIO1_OUTMODE	0x0fe1	/* clr: push/pull, set: open drain */
127 #define	LDF_GPIO67_OUTMODE	0x0fe6	/* clr: push/pull, set: open drain */
128 
129 /*
130  * Internal GPIO bank description, including register addresses and cached
131  * register content.
132  */
133 struct nct_bank {
134 	/* Pin descriptions */
135 	u_int8_t	nb_firstpin;
136 	u_int8_t	nb_numpins;
137 	u_int8_t	nb_enabled;
138 
139 	/* Cached values */
140 	u_int8_t	nb_val_dir;
141 	u_int8_t	nb_val_inv;
142 	u_int8_t	nb_val_mode;
143 
144 	/* Register addresses */
145 	u_int16_t	nb_reg_dir;
146 	u_int16_t	nb_reg_data;
147 	u_int16_t	nb_reg_inv;
148 	u_int16_t	nb_reg_stat;
149 	u_int16_t	nb_reg_mode;
150 };
151 
152 /*
153  * Driver instance.
154  */
155 struct nct_softc {
156 	device_t		sc_dev;			/* MI device */
157 	bus_space_tag_t		sc_iot;			/* I/O tag */
158 	bus_space_handle_t	sc_ioh;			/* I/O handle */
159 	struct gpio_chipset_tag	 sc_gc;			/* GPIO tag */
160 	gpio_pin_t		sc_pins[NCT_NUM_PINS];	/* GPIO pin descr. */
161 
162 	/* Access to the remaining members is covered by sc_lock. */
163 	kmutex_t		sc_lock;		/* Serialization */
164 	int			sc_curdev;		/* Cur. logical dev */
165 	int			sc_curreg;		/* Cur. register */
166 	struct nct_bank		sc_bank[3];		/* Bank descriptions */
167 };
168 
169 static void	nct_attach(device_t, device_t, void *);
170 static int	nct_detach(device_t, int);
171 static void	nct_gpio_ctl(void *, int, int);
172 static int	nct_gpio_read(void *, int);
173 static void	nct_gpio_write(void *, int, int);
174 static int	nct_match(device_t, cfdata_t , void *);
175 static u_int8_t	nct_rd(struct nct_softc *, int);
176 static struct	nct_bank *nct_sel(struct nct_softc *, int, u_int8_t *);
177 static void	nct_wr(struct nct_softc *, int, u_int8_t);
178 
179 static inline void
nct_outb(struct nct_softc * sc,int reg,u_int8_t data)180 nct_outb(struct nct_softc *sc, int reg, u_int8_t data)
181 {
182 
183 	bus_space_write_1(sc->sc_iot, sc->sc_ioh, reg, data);
184 }
185 
186 static inline u_int8_t
nct_inb(struct nct_softc * sc,int reg)187 nct_inb(struct nct_softc *sc, int reg)
188 {
189 
190 	return bus_space_read_1(sc->sc_iot, sc->sc_ioh, reg);
191 }
192 
193 CFATTACH_DECL_NEW(nct,
194 		  sizeof(struct nct_softc),
195 		  nct_match,
196 		  nct_attach,
197 		  nct_detach,
198 		  NULL);
199 
200 MODULE(MODULE_CLASS_DRIVER, nct, "gpio");
201 
202 /*
203  * Module linkage.
204  */
205 #ifdef _MODULE
206 #include "ioconf.c"
207 #endif
208 
209 static int
nct_modcmd(modcmd_t cmd,void * priv)210 nct_modcmd(modcmd_t cmd, void *priv)
211 {
212 	int error = 0;
213 
214 	switch (cmd) {
215 	case MODULE_CMD_INIT:
216 #ifdef _MODULE
217 		error = config_init_component(cfdriver_ioconf_nct,
218 		    cfattach_ioconf_nct, cfdata_ioconf_nct);
219 #endif
220 		return error;
221 	case MODULE_CMD_FINI:
222 #ifdef _MODULE
223 		error = config_fini_component(cfdriver_ioconf_nct,
224 		    cfattach_ioconf_nct, cfdata_ioconf_nct);
225 #endif
226 		return error;
227 	default:
228 		return ENOTTY;
229 	}
230 }
231 
232 /*
233  * Probe for device.
234  */
235 static int
nct_match(device_t parent,cfdata_t match,void * aux)236 nct_match(device_t parent, cfdata_t match, void *aux)
237 {
238 	int ioaddrs[2] = { 0x2e, 0x4e };
239 	struct isa_attach_args *ia = aux;
240 	bus_space_handle_t ioh;
241 	int nioaddr, i;
242 	u_int8_t low, high;
243 	u_int16_t id;
244 	const char *vendor;
245 
246 	/*
247 	 * Allow override of I/O base address.  If no I/O base address is
248 	 * provided, proceed to probe if running on a PC Engines system.
249 	 */
250 	if (ia->ia_nio > 0 && ia->ia_io[0].ir_addr != ISA_UNKNOWN_PORT) {
251 		ioaddrs[0] = ia->ia_io[0].ir_addr;
252 		nioaddr = 1;
253 	} else {
254 		vendor = pmf_get_platform("system-vendor");
255 		if (vendor != NULL && strstr(vendor, "PC Engines") != NULL) {
256 			nioaddr = __arraycount(ioaddrs);
257 		} else {
258 			nioaddr = 0;
259 		}
260 	}
261 
262 	/*
263 	 * Probe at the selected addresses, if any.
264 	 */
265 	for (i = 0; i < nioaddr; i++) {
266 		if (bus_space_map(ia->ia_iot, ioaddrs[i], NCT_IOSIZE, 0,
267 		    &ioh) != 0) {
268 		    continue;
269 		}
270                 /* Unlock chip */
271 		bus_space_write_1(ia->ia_iot, ioh, NCT_PORT_SELECT,
272 		    NCT_KEY_UNLOCK);
273 		bus_space_write_1(ia->ia_iot, ioh, NCT_PORT_SELECT,
274 		    NCT_KEY_UNLOCK);
275 		/* Read ID */
276 		bus_space_write_1(ia->ia_iot, ioh, NCT_PORT_SELECT, GD_ID_LOW);
277 		low = bus_space_read_1(ia->ia_iot, ioh, NCT_PORT_DATA);
278 		bus_space_write_1(ia->ia_iot, ioh, NCT_PORT_SELECT, GD_ID_HIGH);
279 		high = bus_space_read_1(ia->ia_iot, ioh, NCT_PORT_DATA);
280 		id = (u_int16_t)low | ((u_int16_t)high << 8);
281 		bus_space_unmap(ia->ia_iot, ioh, NCT_IOSIZE);
282 		if (id == NCT_CHIP_ID_1 || id == NCT_CHIP_ID_2) {
283 			ia->ia_nirq = 0;
284 			ia->ia_ndrq = 0;
285 			ia->ia_niomem = 0;
286 			ia->ia_nio = 1;
287 			ia->ia_io[0].ir_size = NCT_IOSIZE;
288 			ia->ia_io[0].ir_addr = ioaddrs[i];
289 			return 1;
290 		}
291 	}
292 	return 0;
293 }
294 
295 /*
296  * Attach device instance.
297  */
298 static void
nct_attach(device_t parent,device_t self,void * aux)299 nct_attach(device_t parent, device_t self, void *aux)
300 {
301 	struct nct_softc *sc = device_private(self);
302 	struct isa_attach_args *ia = aux;
303 	struct gpiobus_attach_args gba;
304 	struct nct_bank *nb;
305 	u_int8_t multifun, enable;
306 	int i, j;
307 
308 	/*
309 	 * Set up register space and basics of our state.
310 	 */
311 	if (bus_space_map(ia->ia_iot, ia->ia_io[0].ir_addr,
312 	    ia->ia_io[0].ir_size, 0, &sc->sc_ioh) != 0) {
313 		aprint_normal(": can't map i/o space\n");
314 		return;
315 	}
316 	aprint_normal(": Nuvoton NCT5104D GPIO\n");
317 	sc->sc_dev = self;
318 	sc->sc_iot = ia->ia_iot;
319 	sc->sc_curdev = -1;
320 	sc->sc_curreg = -1;
321 
322         /*
323          * All pin access is funneled through a common, indirect register
324          * interface.  The gpio framework doesn't serialize calls to our
325          * access methods, so do it internally.  This is likely such a
326          * common requirement that it should be factored out as is done for
327          * audio devices, allowing the driver to specify the appropriate
328          * locks.  Anyhow, acquire the lock immediately to pacify locking
329          * assertions.
330          */
331         mutex_init(&sc->sc_lock, MUTEX_DEFAULT, IPL_VM);
332 	mutex_spin_enter(&sc->sc_lock);
333 
334         /*
335          * Disable watchdog timer and GPIO alternate I/O mapping.
336          */
337         nct_wr(sc, LD8_DEVCFG, 0);
338 
339 	/*
340 	 * The BIOS doesn't set things up the way we want.  Pfft.
341 	 * Enable all GPIO0/GPIO1 pins.
342 	 */
343 	multifun = nct_rd(sc, GD_MULTIFUN);
344 	nct_wr(sc, GD_MULTIFUN,
345 	    multifun & ~(GD_MULTIFUN_GPIO0 | GD_MULTIFUN_GPIO1));
346 	nct_wr(sc, LDA_UARTC_ENABLE, 0);
347 	nct_wr(sc, LD8_GPIO0_MULTIFUNC, 0);
348 	nct_wr(sc, LDB_UARTD_ENABLE, 0);
349 	nct_wr(sc, LD8_GPIO1_MULTIFUNC, 0);
350 	multifun = nct_rd(sc, GD_MULTIFUN);
351 	enable = nct_rd(sc, LD7_ENABLE) | LD7_ENABLE_GPIO0 | LD7_ENABLE_GPIO1;
352 
353 	nb = &sc->sc_bank[0];
354 	nb->nb_firstpin = 0;
355 	nb->nb_numpins = 8;
356 	nb->nb_enabled = 0xff;
357 	nb->nb_reg_dir = LD7_GPIO0_DIRECTION;
358 	nb->nb_reg_data = LD7_GPIO0_DATA;
359 	nb->nb_reg_inv = LD7_GPIO0_INVERSION;
360 	nb->nb_reg_stat = LD7_GPIO0_STATUS;
361 	nb->nb_reg_mode = LDF_GPIO0_OUTMODE;
362 
363 	nb = &sc->sc_bank[1];
364 	nb->nb_firstpin = 8;
365 	nb->nb_numpins = 8;
366 	nb->nb_enabled = 0xff;
367 	nb->nb_reg_dir = LD7_GPIO1_DIRECTION;
368 	nb->nb_reg_data = LD7_GPIO1_DATA;
369 	nb->nb_reg_inv = LD7_GPIO1_INVERSION;
370 	nb->nb_reg_stat = LD7_GPIO1_STATUS;
371 	nb->nb_reg_mode = LDF_GPIO1_OUTMODE;
372 
373 	nb = &sc->sc_bank[2];
374 	nb->nb_firstpin = 16;
375 	nb->nb_numpins = 1;
376 	nb->nb_reg_dir = LD7_GPIO67_DIRECTION;
377 	nb->nb_reg_data = LD7_GPIO67_DATA;
378 	nb->nb_reg_stat = LD7_GPIO67_STATUS;
379 	nb->nb_reg_mode = LDF_GPIO67_OUTMODE;
380 	if ((multifun & GD_MULTIFUN_GPIO67) != 0 &&
381 	    (nct_rd(sc, GD_GLOBOPT) & GD_GLOBOPT_GPIO67) == 0) {
382 		nct_wr(sc, LD8_GPIO67_MULTIFUNC, 0);
383 		nb->nb_enabled = 0x01;
384 		enable |= LD7_ENABLE_GPIO67;
385 	} else {
386 		sc->sc_bank[2].nb_enabled = 0;
387 	}
388 
389 	/*
390 	 * Display enabled pins and enable GPIO devices accordingly.
391 	 */
392 	nct_wr(sc, LD7_ENABLE, enable);
393 	mutex_spin_exit(&sc->sc_lock);
394 
395 	aprint_normal_dev(self,
396 	    "enabled pins: GPIO0(%02x) GPIO1(%02x) GPIO67(%01x)\n",
397 	    (unsigned)sc->sc_bank[0].nb_enabled,
398 	    (unsigned)sc->sc_bank[1].nb_enabled,
399 	    (unsigned)sc->sc_bank[2].nb_enabled);
400 
401 	/*
402 	 * Fill pin descriptions and initialize registers.
403 	 */
404 	memset(sc->sc_pins, 0, sizeof(sc->sc_pins));
405 	for (i = 0; i < __arraycount(sc->sc_bank); i++) {
406 		nb = &sc->sc_bank[i];
407 		mutex_spin_enter(&sc->sc_lock);
408 		nb->nb_val_dir = nct_rd(sc, nb->nb_reg_dir);
409 		nb->nb_val_inv = nct_rd(sc, nb->nb_reg_inv);
410 		nb->nb_val_mode = nct_rd(sc, nb->nb_reg_mode);
411 		mutex_spin_exit(&sc->sc_lock);
412 		for (j = 0; j < nb->nb_numpins; j++) {
413 			gpio_pin_t *pin = &sc->sc_pins[nb->nb_firstpin + j];
414 			pin->pin_num = nb->nb_firstpin + j;
415 			/* Skip pin if not configured as GPIO. */
416 			if ((nb->nb_enabled & (1 << j)) == 0) {
417 				continue;
418 			}
419 			pin->pin_caps =
420 			    GPIO_PIN_INPUT | GPIO_PIN_OUTPUT |
421 			    GPIO_PIN_OPENDRAIN |
422 			    GPIO_PIN_PUSHPULL | GPIO_PIN_TRISTATE |
423 			    GPIO_PIN_INVIN | GPIO_PIN_INVOUT;
424 			pin->pin_flags =
425 			    GPIO_PIN_INPUT | GPIO_PIN_OPENDRAIN;
426 			nct_gpio_ctl(sc, pin->pin_num, pin->pin_flags);
427 			pin->pin_state = nct_gpio_read(sc, pin->pin_num);
428 		}
429 	}
430 
431 	/*
432 	 * Attach to gpio framework, and attach all pins unconditionally.
433 	 * If the pins are disabled, we'll ignore any access later.
434 	 */
435 	sc->sc_gc.gp_cookie = sc;
436 	sc->sc_gc.gp_pin_read = nct_gpio_read;
437 	sc->sc_gc.gp_pin_write = nct_gpio_write;
438 	sc->sc_gc.gp_pin_ctl = nct_gpio_ctl;
439 
440 	gba.gba_gc = &sc->sc_gc;
441 	gba.gba_pins = sc->sc_pins;
442 	gba.gba_npins = NCT_NUM_PINS;
443 
444 	(void)config_found(sc->sc_dev, &gba, gpiobus_print, CFARGS_NONE);
445 }
446 
447 /*
448  * Detach device instance.
449  */
450 static int
nct_detach(device_t self,int flags)451 nct_detach(device_t self, int flags)
452 {
453 	struct nct_softc *sc = device_private(self);
454 
455 	bus_space_unmap(sc->sc_iot, sc->sc_ioh, NCT_IOSIZE);
456 	mutex_destroy(&sc->sc_lock);
457 	return 0;
458 }
459 
460 /*
461  * Read byte from specified register.
462  */
463 static u_int8_t
nct_rd(struct nct_softc * sc,int reg)464 nct_rd(struct nct_softc *sc, int reg)
465 {
466 	int dev;
467 
468 	KASSERT(mutex_owned(&sc->sc_lock));
469 
470 	dev = reg >> 8;
471 	reg &= 0xff;
472 
473 	if (dev != sc->sc_curdev && dev != 0x00) {
474 		sc->sc_curdev = dev;
475 		sc->sc_curreg = reg;
476 		nct_outb(sc, NCT_PORT_SELECT, GD_DEVSEL);
477 		nct_outb(sc, NCT_PORT_DATA, dev);
478 		nct_outb(sc, NCT_PORT_SELECT, reg);
479 		return nct_inb(sc, NCT_PORT_DATA);
480 	} else if (reg != sc->sc_curreg) {
481 		sc->sc_curreg = reg;
482 		nct_outb(sc, NCT_PORT_SELECT, reg);
483 		return nct_inb(sc, NCT_PORT_DATA);
484 	} else {
485 		return nct_inb(sc, NCT_PORT_DATA);
486 	}
487 }
488 
489 /*
490  * Write byte to specified register.
491  */
492 static void
nct_wr(struct nct_softc * sc,int reg,u_int8_t data)493 nct_wr(struct nct_softc *sc, int reg, u_int8_t data)
494 {
495 	int dev;
496 
497 	KASSERT(mutex_owned(&sc->sc_lock));
498 
499 	dev = reg >> 8;
500 	reg &= 0xff;
501 
502 	if (dev != sc->sc_curdev && dev != 0x00) {
503 		sc->sc_curdev = dev;
504 		sc->sc_curreg = reg;
505 		nct_outb(sc, NCT_PORT_SELECT, GD_DEVSEL);
506 		nct_outb(sc, NCT_PORT_DATA, dev);
507 		nct_outb(sc, NCT_PORT_SELECT, reg);
508 		nct_outb(sc, NCT_PORT_DATA, data);
509 	} else if (reg != sc->sc_curreg) {
510 		sc->sc_curreg = reg;
511 		nct_outb(sc, NCT_PORT_SELECT, reg);
512 		nct_outb(sc, NCT_PORT_DATA, data);
513 	} else {
514 		nct_outb(sc, NCT_PORT_DATA, data);
515 	}
516 }
517 
518 /*
519  * Given pin number, return bank and pin mask.  This alters no state and so
520  * can safely be called without the mutex held.
521  */
522 static struct nct_bank *
nct_sel(struct nct_softc * sc,int pin,u_int8_t * mask)523 nct_sel(struct nct_softc *sc, int pin, u_int8_t *mask)
524 {
525 	struct nct_bank *nb;
526 
527 	KASSERT(pin >= 0 && pin < NCT_NUM_PINS);
528 	nb = &sc->sc_bank[pin >> 3];
529 	KASSERT(pin >= nb->nb_firstpin);
530 	KASSERT((pin & 7) < nb->nb_numpins);
531 	*mask = (u_int8_t)(1 << (pin & 7)) & nb->nb_enabled;
532 	return nb;
533 }
534 
535 /*
536  * GPIO hook: read pin.
537  */
538 static int
nct_gpio_read(void * arg,int pin)539 nct_gpio_read(void *arg, int pin)
540 {
541 	struct nct_softc *sc = arg;
542 	struct nct_bank *nb;
543 	u_int8_t data, mask;
544 	int rv = GPIO_PIN_LOW;
545 
546 	nb = nct_sel(sc, pin, &mask);
547 	if (__predict_true(mask != 0)) {
548 		mutex_spin_enter(&sc->sc_lock);
549 		data = nct_rd(sc, nb->nb_reg_data);
550 		if ((data & mask) != 0) {
551 			rv = GPIO_PIN_HIGH;
552 		}
553 		mutex_spin_exit(&sc->sc_lock);
554 	}
555 	return rv;
556 }
557 
558 /*
559  * GPIO hook: write pin.
560  */
561 static void
nct_gpio_write(void * arg,int pin,int val)562 nct_gpio_write(void *arg, int pin, int val)
563 {
564 	struct nct_softc *sc = arg;
565 	struct nct_bank *nb;
566 	u_int8_t data, mask;
567 
568 	nb = nct_sel(sc, pin, &mask);
569 	if (__predict_true(mask != 0)) {
570 		mutex_spin_enter(&sc->sc_lock);
571 		data = nct_rd(sc, nb->nb_reg_data);
572 		if (val == GPIO_PIN_LOW) {
573 			data &= ~mask;
574 		} else if (val == GPIO_PIN_HIGH) {
575 			data |= mask;
576 		}
577 		nct_wr(sc, nb->nb_reg_data, data);
578 		mutex_spin_exit(&sc->sc_lock);
579 	}
580 }
581 
582 /*
583  * GPIO hook: change pin parameters.
584  */
585 static void
nct_gpio_ctl(void * arg,int pin,int flg)586 nct_gpio_ctl(void *arg, int pin, int flg)
587 {
588 	struct nct_softc *sc = arg;
589 	struct nct_bank *nb;
590 	u_int8_t data, mask;
591 
592 	nb = nct_sel(sc, pin, &mask);
593 	if (__predict_false(mask == 0)) {
594 		return;
595 	}
596 
597 	/*
598 	 * Set input direction early to avoid perturbation.
599 	 */
600 	mutex_spin_enter(&sc->sc_lock);
601 	data = nb->nb_val_dir;
602 	if ((flg & (GPIO_PIN_INPUT | GPIO_PIN_TRISTATE)) != 0) {
603 		data |= mask;
604 	}
605 	if (data != nb->nb_val_dir) {
606 		nct_wr(sc, nb->nb_reg_dir, data);
607 		nb->nb_val_dir = data;
608 	}
609 
610 	/*
611 	 * Set inversion.
612 	 */
613 	data = nb->nb_val_inv;
614 	if ((flg & (GPIO_PIN_OUTPUT | GPIO_PIN_INVOUT)) ==
615 	             (GPIO_PIN_OUTPUT | GPIO_PIN_INVOUT) ||
616             (flg & (GPIO_PIN_INPUT | GPIO_PIN_INVIN)) ==
617   	             (GPIO_PIN_INPUT | GPIO_PIN_INVIN)) {
618 		data |= mask;
619 	} else {
620 		data &= ~mask;
621 	}
622 	if (data != nb->nb_val_inv) {
623 		nct_wr(sc, nb->nb_reg_inv, data);
624 		nb->nb_val_inv = data;
625 	}
626 
627 	/*
628 	 * Set drain mode.
629 	 */
630 	data = nb->nb_val_mode;
631 	if ((flg & GPIO_PIN_PUSHPULL) != 0) {
632 		data |= mask;
633 	} else /* GPIO_PIN_OPENDRAIN */ {
634 		data &= ~mask;
635 	}
636 	if (data != nb->nb_val_mode) {
637 		nct_wr(sc, nb->nb_reg_mode, data);
638 		nb->nb_val_mode = data;
639 	}
640 
641 	/*
642 	 * Set output direction late to avoid perturbation.
643 	 */
644 	data = nb->nb_val_dir;
645 	if ((flg & (GPIO_PIN_OUTPUT | GPIO_PIN_TRISTATE)) == GPIO_PIN_OUTPUT) {
646 		data &= ~mask;
647 	}
648 	if (data != nb->nb_val_dir) {
649 		nct_wr(sc, nb->nb_reg_dir, data);
650 		nb->nb_val_dir = data;
651 	}
652 	mutex_spin_exit(&sc->sc_lock);
653 }
654