xref: /linux/drivers/platform/cznic/turris-omnia-mcu-gpio.c (revision a1ff5a7d78a036d6c2178ee5acd6ba4946243800)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * CZ.NIC's Turris Omnia MCU GPIO and IRQ driver
4  *
5  * 2024 by Marek Behún <kabel@kernel.org>
6  */
7 
8 #include <linux/array_size.h>
9 #include <linux/bitfield.h>
10 #include <linux/bitops.h>
11 #include <linux/bug.h>
12 #include <linux/cleanup.h>
13 #include <linux/device.h>
14 #include <linux/devm-helpers.h>
15 #include <linux/errno.h>
16 #include <linux/gpio/driver.h>
17 #include <linux/i2c.h>
18 #include <linux/interrupt.h>
19 #include <linux/mutex.h>
20 #include <linux/sysfs.h>
21 #include <linux/types.h>
22 #include <linux/workqueue.h>
23 #include <asm/unaligned.h>
24 
25 #include <linux/turris-omnia-mcu-interface.h>
26 #include "turris-omnia-mcu.h"
27 
28 #define OMNIA_CMD_INT_ARG_LEN		8
29 #define FRONT_BUTTON_RELEASE_DELAY_MS	50
30 
31 static const char * const omnia_mcu_gpio_templates[64] = {
32 	/* GPIOs with value read from the 16-bit wide status */
33 	[4]  = "MiniPCIe0 Card Detect",
34 	[5]  = "MiniPCIe0 mSATA Indicator",
35 	[6]  = "Front USB3 port over-current",
36 	[7]  = "Rear USB3 port over-current",
37 	[8]  = "Front USB3 port power",
38 	[9]  = "Rear USB3 port power",
39 	[12] = "Front Button",
40 
41 	/* GPIOs with value read from the 32-bit wide extended status */
42 	[16] = "SFP nDET",
43 	[28] = "MiniPCIe0 LED",
44 	[29] = "MiniPCIe1 LED",
45 	[30] = "MiniPCIe2 LED",
46 	[31] = "MiniPCIe0 PAN LED",
47 	[32] = "MiniPCIe1 PAN LED",
48 	[33] = "MiniPCIe2 PAN LED",
49 	[34] = "WAN PHY LED0",
50 	[35] = "WAN PHY LED1",
51 	[36] = "LAN switch p0 LED0",
52 	[37] = "LAN switch p0 LED1",
53 	[38] = "LAN switch p1 LED0",
54 	[39] = "LAN switch p1 LED1",
55 	[40] = "LAN switch p2 LED0",
56 	[41] = "LAN switch p2 LED1",
57 	[42] = "LAN switch p3 LED0",
58 	[43] = "LAN switch p3 LED1",
59 	[44] = "LAN switch p4 LED0",
60 	[45] = "LAN switch p4 LED1",
61 	[46] = "LAN switch p5 LED0",
62 	[47] = "LAN switch p5 LED1",
63 
64 	/* GPIOs with value read from the 16-bit wide extended control status */
65 	[48] = "eMMC nRESET",
66 	[49] = "LAN switch nRESET",
67 	[50] = "WAN PHY nRESET",
68 	[51] = "MiniPCIe0 nPERST",
69 	[52] = "MiniPCIe1 nPERST",
70 	[53] = "MiniPCIe2 nPERST",
71 	[54] = "WAN PHY SFP mux",
72 	[56] = "VHV power disable",
73 };
74 
75 struct omnia_gpio {
76 	u8 cmd;
77 	u8 ctl_cmd;
78 	u8 bit;
79 	u8 ctl_bit;
80 	u8 int_bit;
81 	u16 feat;
82 	u16 feat_mask;
83 };
84 
85 #define OMNIA_GPIO_INVALID_INT_BIT	0xff
86 
87 #define _DEF_GPIO(_cmd, _ctl_cmd, _bit, _ctl_bit, _int_bit, _feat, _feat_mask) \
88 	{								\
89 		.cmd = _cmd,						\
90 		.ctl_cmd = _ctl_cmd,					\
91 		.bit = _bit,						\
92 		.ctl_bit = _ctl_bit,					\
93 		.int_bit = (_int_bit) < 0 ? OMNIA_GPIO_INVALID_INT_BIT	\
94 					  : (_int_bit),			\
95 		.feat = _feat,						\
96 		.feat_mask = _feat_mask,				\
97 	}
98 
99 #define _DEF_GPIO_STS(_name) \
100 	_DEF_GPIO(OMNIA_CMD_GET_STATUS_WORD, 0, __bf_shf(OMNIA_STS_ ## _name), \
101 		  0, __bf_shf(OMNIA_INT_ ## _name), 0, 0)
102 
103 #define _DEF_GPIO_CTL(_name) \
104 	_DEF_GPIO(OMNIA_CMD_GET_STATUS_WORD, OMNIA_CMD_GENERAL_CONTROL, \
105 		  __bf_shf(OMNIA_STS_ ## _name), __bf_shf(OMNIA_CTL_ ## _name), \
106 		  -1, 0, 0)
107 
108 #define _DEF_GPIO_EXT_STS(_name, _feat) \
109 	_DEF_GPIO(OMNIA_CMD_GET_EXT_STATUS_DWORD, 0, \
110 		  __bf_shf(OMNIA_EXT_STS_ ## _name), 0, \
111 		  __bf_shf(OMNIA_INT_ ## _name), \
112 		  OMNIA_FEAT_ ## _feat | OMNIA_FEAT_EXT_CMDS, \
113 		  OMNIA_FEAT_ ## _feat | OMNIA_FEAT_EXT_CMDS)
114 
115 #define _DEF_GPIO_EXT_STS_LED(_name, _ledext) \
116 	_DEF_GPIO(OMNIA_CMD_GET_EXT_STATUS_DWORD, 0, \
117 		  __bf_shf(OMNIA_EXT_STS_ ## _name), 0, \
118 		  __bf_shf(OMNIA_INT_ ## _name), \
119 		  OMNIA_FEAT_LED_STATE_ ## _ledext, \
120 		  OMNIA_FEAT_LED_STATE_EXT_MASK)
121 
122 #define _DEF_GPIO_EXT_STS_LEDALL(_name) \
123 	_DEF_GPIO(OMNIA_CMD_GET_EXT_STATUS_DWORD, 0, \
124 		  __bf_shf(OMNIA_EXT_STS_ ## _name), 0, \
125 		  __bf_shf(OMNIA_INT_ ## _name), \
126 		  OMNIA_FEAT_LED_STATE_EXT_MASK, 0)
127 
128 #define _DEF_GPIO_EXT_CTL(_name, _feat) \
129 	_DEF_GPIO(OMNIA_CMD_GET_EXT_CONTROL_STATUS, OMNIA_CMD_EXT_CONTROL, \
130 		  __bf_shf(OMNIA_EXT_CTL_ ## _name), \
131 		  __bf_shf(OMNIA_EXT_CTL_ ## _name), -1, \
132 		  OMNIA_FEAT_ ## _feat | OMNIA_FEAT_EXT_CMDS, \
133 		  OMNIA_FEAT_ ## _feat | OMNIA_FEAT_EXT_CMDS)
134 
135 #define _DEF_INT(_name) \
136 	_DEF_GPIO(0, 0, 0, 0, __bf_shf(OMNIA_INT_ ## _name), 0, 0)
137 
138 static inline bool is_int_bit_valid(const struct omnia_gpio *gpio)
139 {
140 	return gpio->int_bit != OMNIA_GPIO_INVALID_INT_BIT;
141 }
142 
143 static const struct omnia_gpio omnia_gpios[64] = {
144 	/* GPIOs with value read from the 16-bit wide status */
145 	[4]  = _DEF_GPIO_STS(CARD_DET),
146 	[5]  = _DEF_GPIO_STS(MSATA_IND),
147 	[6]  = _DEF_GPIO_STS(USB30_OVC),
148 	[7]  = _DEF_GPIO_STS(USB31_OVC),
149 	[8]  = _DEF_GPIO_CTL(USB30_PWRON),
150 	[9]  = _DEF_GPIO_CTL(USB31_PWRON),
151 
152 	/* brightness changed interrupt, no GPIO */
153 	[11] = _DEF_INT(BRIGHTNESS_CHANGED),
154 
155 	[12] = _DEF_GPIO_STS(BUTTON_PRESSED),
156 
157 	/* TRNG interrupt, no GPIO */
158 	[13] = _DEF_INT(TRNG),
159 
160 	/* MESSAGE_SIGNED interrupt, no GPIO */
161 	[14] = _DEF_INT(MESSAGE_SIGNED),
162 
163 	/* GPIOs with value read from the 32-bit wide extended status */
164 	[16] = _DEF_GPIO_EXT_STS(SFP_nDET, PERIPH_MCU),
165 	[28] = _DEF_GPIO_EXT_STS_LEDALL(WLAN0_MSATA_LED),
166 	[29] = _DEF_GPIO_EXT_STS_LEDALL(WLAN1_LED),
167 	[30] = _DEF_GPIO_EXT_STS_LEDALL(WLAN2_LED),
168 	[31] = _DEF_GPIO_EXT_STS_LED(WPAN0_LED, EXT),
169 	[32] = _DEF_GPIO_EXT_STS_LED(WPAN1_LED, EXT),
170 	[33] = _DEF_GPIO_EXT_STS_LED(WPAN2_LED, EXT),
171 	[34] = _DEF_GPIO_EXT_STS_LEDALL(WAN_LED0),
172 	[35] = _DEF_GPIO_EXT_STS_LED(WAN_LED1, EXT_V32),
173 	[36] = _DEF_GPIO_EXT_STS_LEDALL(LAN0_LED0),
174 	[37] = _DEF_GPIO_EXT_STS_LEDALL(LAN0_LED1),
175 	[38] = _DEF_GPIO_EXT_STS_LEDALL(LAN1_LED0),
176 	[39] = _DEF_GPIO_EXT_STS_LEDALL(LAN1_LED1),
177 	[40] = _DEF_GPIO_EXT_STS_LEDALL(LAN2_LED0),
178 	[41] = _DEF_GPIO_EXT_STS_LEDALL(LAN2_LED1),
179 	[42] = _DEF_GPIO_EXT_STS_LEDALL(LAN3_LED0),
180 	[43] = _DEF_GPIO_EXT_STS_LEDALL(LAN3_LED1),
181 	[44] = _DEF_GPIO_EXT_STS_LEDALL(LAN4_LED0),
182 	[45] = _DEF_GPIO_EXT_STS_LEDALL(LAN4_LED1),
183 	[46] = _DEF_GPIO_EXT_STS_LEDALL(LAN5_LED0),
184 	[47] = _DEF_GPIO_EXT_STS_LEDALL(LAN5_LED1),
185 
186 	/* GPIOs with value read from the 16-bit wide extended control status */
187 	[48] = _DEF_GPIO_EXT_CTL(nRES_MMC, PERIPH_MCU),
188 	[49] = _DEF_GPIO_EXT_CTL(nRES_LAN, PERIPH_MCU),
189 	[50] = _DEF_GPIO_EXT_CTL(nRES_PHY, PERIPH_MCU),
190 	[51] = _DEF_GPIO_EXT_CTL(nPERST0, PERIPH_MCU),
191 	[52] = _DEF_GPIO_EXT_CTL(nPERST1, PERIPH_MCU),
192 	[53] = _DEF_GPIO_EXT_CTL(nPERST2, PERIPH_MCU),
193 	[54] = _DEF_GPIO_EXT_CTL(PHY_SFP, PERIPH_MCU),
194 	[56] = _DEF_GPIO_EXT_CTL(nVHV_CTRL, PERIPH_MCU),
195 };
196 
197 /* mapping from interrupts to indexes of GPIOs in the omnia_gpios array */
198 const u8 omnia_int_to_gpio_idx[32] = {
199 	[__bf_shf(OMNIA_INT_CARD_DET)]			= 4,
200 	[__bf_shf(OMNIA_INT_MSATA_IND)]			= 5,
201 	[__bf_shf(OMNIA_INT_USB30_OVC)]			= 6,
202 	[__bf_shf(OMNIA_INT_USB31_OVC)]			= 7,
203 	[__bf_shf(OMNIA_INT_BUTTON_PRESSED)]		= 12,
204 	[__bf_shf(OMNIA_INT_TRNG)]			= 13,
205 	[__bf_shf(OMNIA_INT_MESSAGE_SIGNED)]		= 14,
206 	[__bf_shf(OMNIA_INT_SFP_nDET)]			= 16,
207 	[__bf_shf(OMNIA_INT_BRIGHTNESS_CHANGED)]	= 11,
208 	[__bf_shf(OMNIA_INT_WLAN0_MSATA_LED)]		= 28,
209 	[__bf_shf(OMNIA_INT_WLAN1_LED)]			= 29,
210 	[__bf_shf(OMNIA_INT_WLAN2_LED)]			= 30,
211 	[__bf_shf(OMNIA_INT_WPAN0_LED)]			= 31,
212 	[__bf_shf(OMNIA_INT_WPAN1_LED)]			= 32,
213 	[__bf_shf(OMNIA_INT_WPAN2_LED)]			= 33,
214 	[__bf_shf(OMNIA_INT_WAN_LED0)]			= 34,
215 	[__bf_shf(OMNIA_INT_WAN_LED1)]			= 35,
216 	[__bf_shf(OMNIA_INT_LAN0_LED0)]			= 36,
217 	[__bf_shf(OMNIA_INT_LAN0_LED1)]			= 37,
218 	[__bf_shf(OMNIA_INT_LAN1_LED0)]			= 38,
219 	[__bf_shf(OMNIA_INT_LAN1_LED1)]			= 39,
220 	[__bf_shf(OMNIA_INT_LAN2_LED0)]			= 40,
221 	[__bf_shf(OMNIA_INT_LAN2_LED1)]			= 41,
222 	[__bf_shf(OMNIA_INT_LAN3_LED0)]			= 42,
223 	[__bf_shf(OMNIA_INT_LAN3_LED1)]			= 43,
224 	[__bf_shf(OMNIA_INT_LAN4_LED0)]			= 44,
225 	[__bf_shf(OMNIA_INT_LAN4_LED1)]			= 45,
226 	[__bf_shf(OMNIA_INT_LAN5_LED0)]			= 46,
227 	[__bf_shf(OMNIA_INT_LAN5_LED1)]			= 47,
228 };
229 
230 /* index of PHY_SFP GPIO in the omnia_gpios array */
231 #define OMNIA_GPIO_PHY_SFP_OFFSET	54
232 
233 static int omnia_ctl_cmd_locked(struct omnia_mcu *mcu, u8 cmd, u16 val, u16 mask)
234 {
235 	unsigned int len;
236 	u8 buf[5];
237 
238 	buf[0] = cmd;
239 
240 	switch (cmd) {
241 	case OMNIA_CMD_GENERAL_CONTROL:
242 		buf[1] = val;
243 		buf[2] = mask;
244 		len = 3;
245 		break;
246 
247 	case OMNIA_CMD_EXT_CONTROL:
248 		put_unaligned_le16(val, &buf[1]);
249 		put_unaligned_le16(mask, &buf[3]);
250 		len = 5;
251 		break;
252 
253 	default:
254 		BUG();
255 	}
256 
257 	return omnia_cmd_write(mcu->client, buf, len);
258 }
259 
260 static int omnia_ctl_cmd(struct omnia_mcu *mcu, u8 cmd, u16 val, u16 mask)
261 {
262 	guard(mutex)(&mcu->lock);
263 
264 	return omnia_ctl_cmd_locked(mcu, cmd, val, mask);
265 }
266 
267 static int omnia_gpio_request(struct gpio_chip *gc, unsigned int offset)
268 {
269 	if (!omnia_gpios[offset].cmd)
270 		return -EINVAL;
271 
272 	return 0;
273 }
274 
275 static int omnia_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
276 {
277 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
278 
279 	if (offset == OMNIA_GPIO_PHY_SFP_OFFSET) {
280 		int val;
281 
282 		scoped_guard(mutex, &mcu->lock) {
283 			val = omnia_cmd_read_bit(mcu->client,
284 						 OMNIA_CMD_GET_EXT_CONTROL_STATUS,
285 						 OMNIA_EXT_CTL_PHY_SFP_AUTO);
286 			if (val < 0)
287 				return val;
288 		}
289 
290 		if (val)
291 			return GPIO_LINE_DIRECTION_IN;
292 
293 		return GPIO_LINE_DIRECTION_OUT;
294 	}
295 
296 	if (omnia_gpios[offset].ctl_cmd)
297 		return GPIO_LINE_DIRECTION_OUT;
298 
299 	return GPIO_LINE_DIRECTION_IN;
300 }
301 
302 static int omnia_gpio_direction_input(struct gpio_chip *gc, unsigned int offset)
303 {
304 	const struct omnia_gpio *gpio = &omnia_gpios[offset];
305 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
306 
307 	if (offset == OMNIA_GPIO_PHY_SFP_OFFSET)
308 		return omnia_ctl_cmd(mcu, OMNIA_CMD_EXT_CONTROL,
309 				     OMNIA_EXT_CTL_PHY_SFP_AUTO,
310 				     OMNIA_EXT_CTL_PHY_SFP_AUTO);
311 
312 	if (gpio->ctl_cmd)
313 		return -ENOTSUPP;
314 
315 	return 0;
316 }
317 
318 static int omnia_gpio_direction_output(struct gpio_chip *gc,
319 				       unsigned int offset, int value)
320 {
321 	const struct omnia_gpio *gpio = &omnia_gpios[offset];
322 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
323 	u16 val, mask;
324 
325 	if (!gpio->ctl_cmd)
326 		return -ENOTSUPP;
327 
328 	mask = BIT(gpio->ctl_bit);
329 	val = value ? mask : 0;
330 
331 	if (offset == OMNIA_GPIO_PHY_SFP_OFFSET)
332 		mask |= OMNIA_EXT_CTL_PHY_SFP_AUTO;
333 
334 	return omnia_ctl_cmd(mcu, gpio->ctl_cmd, val, mask);
335 }
336 
337 static int omnia_gpio_get(struct gpio_chip *gc, unsigned int offset)
338 {
339 	const struct omnia_gpio *gpio = &omnia_gpios[offset];
340 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
341 
342 	/*
343 	 * If firmware does not support the new interrupt API, we are informed
344 	 * of every change of the status word by an interrupt from MCU and save
345 	 * its value in the interrupt service routine. Simply return the saved
346 	 * value.
347 	 */
348 	if (gpio->cmd == OMNIA_CMD_GET_STATUS_WORD &&
349 	    !(mcu->features & OMNIA_FEAT_NEW_INT_API))
350 		return test_bit(gpio->bit, &mcu->last_status);
351 
352 	guard(mutex)(&mcu->lock);
353 
354 	/*
355 	 * If firmware does support the new interrupt API, we may have cached
356 	 * the value of a GPIO in the interrupt service routine. If not, read
357 	 * the relevant bit now.
358 	 */
359 	if (is_int_bit_valid(gpio) && test_bit(gpio->int_bit, &mcu->is_cached))
360 		return test_bit(gpio->int_bit, &mcu->cached);
361 
362 	return omnia_cmd_read_bit(mcu->client, gpio->cmd, BIT(gpio->bit));
363 }
364 
365 static unsigned long *
366 _relevant_field_for_sts_cmd(u8 cmd, unsigned long *sts, unsigned long *ext_sts,
367 			    unsigned long *ext_ctl)
368 {
369 	switch (cmd) {
370 	case OMNIA_CMD_GET_STATUS_WORD:
371 		return sts;
372 	case OMNIA_CMD_GET_EXT_STATUS_DWORD:
373 		return ext_sts;
374 	case OMNIA_CMD_GET_EXT_CONTROL_STATUS:
375 		return ext_ctl;
376 	default:
377 		return NULL;
378 	}
379 }
380 
381 static int omnia_gpio_get_multiple(struct gpio_chip *gc, unsigned long *mask,
382 				   unsigned long *bits)
383 {
384 	unsigned long sts = 0, ext_sts = 0, ext_ctl = 0, *field;
385 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
386 	struct i2c_client *client = mcu->client;
387 	unsigned int i;
388 	int err;
389 
390 	/* determine which bits to read from the 3 possible commands */
391 	for_each_set_bit(i, mask, ARRAY_SIZE(omnia_gpios)) {
392 		field = _relevant_field_for_sts_cmd(omnia_gpios[i].cmd,
393 						    &sts, &ext_sts, &ext_ctl);
394 		if (!field)
395 			continue;
396 
397 		__set_bit(omnia_gpios[i].bit, field);
398 	}
399 
400 	guard(mutex)(&mcu->lock);
401 
402 	if (mcu->features & OMNIA_FEAT_NEW_INT_API) {
403 		/* read relevant bits from status */
404 		err = omnia_cmd_read_bits(client, OMNIA_CMD_GET_STATUS_WORD,
405 					  sts, &sts);
406 		if (err)
407 			return err;
408 	} else {
409 		/*
410 		 * Use status word value cached in the interrupt service routine
411 		 * if firmware does not support the new interrupt API.
412 		 */
413 		sts = mcu->last_status;
414 	}
415 
416 	/* read relevant bits from extended status */
417 	err = omnia_cmd_read_bits(client, OMNIA_CMD_GET_EXT_STATUS_DWORD,
418 				  ext_sts, &ext_sts);
419 	if (err)
420 		return err;
421 
422 	/* read relevant bits from extended control */
423 	err = omnia_cmd_read_bits(client, OMNIA_CMD_GET_EXT_CONTROL_STATUS,
424 				  ext_ctl, &ext_ctl);
425 	if (err)
426 		return err;
427 
428 	/* assign relevant bits in result */
429 	for_each_set_bit(i, mask, ARRAY_SIZE(omnia_gpios)) {
430 		field = _relevant_field_for_sts_cmd(omnia_gpios[i].cmd,
431 						    &sts, &ext_sts, &ext_ctl);
432 		if (!field)
433 			continue;
434 
435 		__assign_bit(i, bits, test_bit(omnia_gpios[i].bit, field));
436 	}
437 
438 	return 0;
439 }
440 
441 static void omnia_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
442 {
443 	const struct omnia_gpio *gpio = &omnia_gpios[offset];
444 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
445 	u16 val, mask;
446 
447 	if (!gpio->ctl_cmd)
448 		return;
449 
450 	mask = BIT(gpio->ctl_bit);
451 	val = value ? mask : 0;
452 
453 	omnia_ctl_cmd(mcu, gpio->ctl_cmd, val, mask);
454 }
455 
456 static void omnia_gpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
457 				    unsigned long *bits)
458 {
459 	unsigned long ctl = 0, ctl_mask = 0, ext_ctl = 0, ext_ctl_mask = 0;
460 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
461 	unsigned int i;
462 
463 	for_each_set_bit(i, mask, ARRAY_SIZE(omnia_gpios)) {
464 		unsigned long *field, *field_mask;
465 		u8 bit = omnia_gpios[i].ctl_bit;
466 
467 		switch (omnia_gpios[i].ctl_cmd) {
468 		case OMNIA_CMD_GENERAL_CONTROL:
469 			field = &ctl;
470 			field_mask = &ctl_mask;
471 			break;
472 		case OMNIA_CMD_EXT_CONTROL:
473 			field = &ext_ctl;
474 			field_mask = &ext_ctl_mask;
475 			break;
476 		default:
477 			field = field_mask = NULL;
478 			break;
479 		}
480 
481 		if (!field)
482 			continue;
483 
484 		__set_bit(bit, field_mask);
485 		__assign_bit(bit, field, test_bit(i, bits));
486 	}
487 
488 	guard(mutex)(&mcu->lock);
489 
490 	if (ctl_mask)
491 		omnia_ctl_cmd_locked(mcu, OMNIA_CMD_GENERAL_CONTROL,
492 				     ctl, ctl_mask);
493 
494 	if (ext_ctl_mask)
495 		omnia_ctl_cmd_locked(mcu, OMNIA_CMD_EXT_CONTROL,
496 				     ext_ctl, ext_ctl_mask);
497 }
498 
499 static bool omnia_gpio_available(struct omnia_mcu *mcu,
500 				 const struct omnia_gpio *gpio)
501 {
502 	if (gpio->feat_mask)
503 		return (mcu->features & gpio->feat_mask) == gpio->feat;
504 
505 	if (gpio->feat)
506 		return mcu->features & gpio->feat;
507 
508 	return true;
509 }
510 
511 static int omnia_gpio_init_valid_mask(struct gpio_chip *gc,
512 				      unsigned long *valid_mask,
513 				      unsigned int ngpios)
514 {
515 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
516 
517 	for (unsigned int i = 0; i < ngpios; i++) {
518 		const struct omnia_gpio *gpio = &omnia_gpios[i];
519 
520 		if (gpio->cmd || is_int_bit_valid(gpio))
521 			__assign_bit(i, valid_mask,
522 				     omnia_gpio_available(mcu, gpio));
523 		else
524 			__clear_bit(i, valid_mask);
525 	}
526 
527 	return 0;
528 }
529 
530 static int omnia_gpio_of_xlate(struct gpio_chip *gc,
531 			       const struct of_phandle_args *gpiospec,
532 			       u32 *flags)
533 {
534 	u32 bank, gpio;
535 
536 	if (WARN_ON(gpiospec->args_count != 3))
537 		return -EINVAL;
538 
539 	if (flags)
540 		*flags = gpiospec->args[2];
541 
542 	bank = gpiospec->args[0];
543 	gpio = gpiospec->args[1];
544 
545 	switch (bank) {
546 	case 0:
547 		return gpio < 16 ? gpio : -EINVAL;
548 	case 1:
549 		return gpio < 32 ? 16 + gpio : -EINVAL;
550 	case 2:
551 		return gpio < 16 ? 48 + gpio : -EINVAL;
552 	default:
553 		return -EINVAL;
554 	}
555 }
556 
557 static void omnia_irq_shutdown(struct irq_data *d)
558 {
559 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
560 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
561 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
562 	u8 bit = omnia_gpios[hwirq].int_bit;
563 
564 	__clear_bit(bit, &mcu->rising);
565 	__clear_bit(bit, &mcu->falling);
566 }
567 
568 static void omnia_irq_mask(struct irq_data *d)
569 {
570 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
571 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
572 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
573 	u8 bit = omnia_gpios[hwirq].int_bit;
574 
575 	if (!omnia_gpios[hwirq].cmd)
576 		__clear_bit(bit, &mcu->rising);
577 	__clear_bit(bit, &mcu->mask);
578 	gpiochip_disable_irq(gc, hwirq);
579 }
580 
581 static void omnia_irq_unmask(struct irq_data *d)
582 {
583 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
584 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
585 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
586 	u8 bit = omnia_gpios[hwirq].int_bit;
587 
588 	gpiochip_enable_irq(gc, hwirq);
589 	__set_bit(bit, &mcu->mask);
590 	if (!omnia_gpios[hwirq].cmd)
591 		__set_bit(bit, &mcu->rising);
592 }
593 
594 static int omnia_irq_set_type(struct irq_data *d, unsigned int type)
595 {
596 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
597 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
598 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
599 	struct device *dev = &mcu->client->dev;
600 	u8 bit = omnia_gpios[hwirq].int_bit;
601 
602 	if (!(type & IRQ_TYPE_EDGE_BOTH)) {
603 		dev_err(dev, "irq %u: unsupported type %u\n", d->irq, type);
604 		return -EINVAL;
605 	}
606 
607 	__assign_bit(bit, &mcu->rising, type & IRQ_TYPE_EDGE_RISING);
608 	__assign_bit(bit, &mcu->falling, type & IRQ_TYPE_EDGE_FALLING);
609 
610 	return 0;
611 }
612 
613 static void omnia_irq_bus_lock(struct irq_data *d)
614 {
615 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
616 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
617 
618 	/* nothing to do if MCU firmware does not support new interrupt API */
619 	if (!(mcu->features & OMNIA_FEAT_NEW_INT_API))
620 		return;
621 
622 	mutex_lock(&mcu->lock);
623 }
624 
625 /**
626  * omnia_mask_interleave - Interleaves the bytes from @rising and @falling
627  * @dst: the destination u8 array of interleaved bytes
628  * @rising: rising mask
629  * @falling: falling mask
630  *
631  * Interleaves the little-endian bytes from @rising and @falling words.
632  *
633  * If @rising = (r0, r1, r2, r3) and @falling = (f0, f1, f2, f3), the result is
634  * @dst = (r0, f0, r1, f1, r2, f2, r3, f3).
635  *
636  * The MCU receives an interrupt mask and reports a pending interrupt bitmap in
637  * this interleaved format. The rationale behind this is that the low-indexed
638  * bits are more important - in many cases, the user will be interested only in
639  * interrupts with indexes 0 to 7, and so the system can stop reading after
640  * first 2 bytes (r0, f0), to save time on the slow I2C bus.
641  *
642  * Feel free to remove this function and its inverse, omnia_mask_deinterleave,
643  * and use an appropriate bitmap_*() function once such a function exists.
644  */
645 static void
646 omnia_mask_interleave(u8 *dst, unsigned long rising, unsigned long falling)
647 {
648 	for (unsigned int i = 0; i < sizeof(u32); i++) {
649 		dst[2 * i] = rising >> (8 * i);
650 		dst[2 * i + 1] = falling >> (8 * i);
651 	}
652 }
653 
654 /**
655  * omnia_mask_deinterleave - Deinterleaves the bytes into @rising and @falling
656  * @src: the source u8 array containing the interleaved bytes
657  * @rising: pointer where to store the rising mask gathered from @src
658  * @falling: pointer where to store the falling mask gathered from @src
659  *
660  * This is the inverse function to omnia_mask_interleave.
661  */
662 static void omnia_mask_deinterleave(const u8 *src, unsigned long *rising,
663 				    unsigned long *falling)
664 {
665 	*rising = *falling = 0;
666 
667 	for (unsigned int i = 0; i < sizeof(u32); i++) {
668 		*rising |= src[2 * i] << (8 * i);
669 		*falling |= src[2 * i + 1] << (8 * i);
670 	}
671 }
672 
673 static void omnia_irq_bus_sync_unlock(struct irq_data *d)
674 {
675 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
676 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
677 	struct device *dev = &mcu->client->dev;
678 	u8 cmd[1 + OMNIA_CMD_INT_ARG_LEN];
679 	unsigned long rising, falling;
680 	int err;
681 
682 	/* nothing to do if MCU firmware does not support new interrupt API */
683 	if (!(mcu->features & OMNIA_FEAT_NEW_INT_API))
684 		return;
685 
686 	cmd[0] = OMNIA_CMD_SET_INT_MASK;
687 
688 	rising = mcu->rising & mcu->mask;
689 	falling = mcu->falling & mcu->mask;
690 
691 	/* interleave the rising and falling bytes into the command arguments */
692 	omnia_mask_interleave(&cmd[1], rising, falling);
693 
694 	dev_dbg(dev, "set int mask %8ph\n", &cmd[1]);
695 
696 	err = omnia_cmd_write(mcu->client, cmd, sizeof(cmd));
697 	if (err) {
698 		dev_err(dev, "Cannot set mask: %d\n", err);
699 		goto unlock;
700 	}
701 
702 	/*
703 	 * Remember which GPIOs have both rising and falling interrupts enabled.
704 	 * For those we will cache their value so that .get() method is faster.
705 	 * We also need to forget cached values of GPIOs that aren't cached
706 	 * anymore.
707 	 */
708 	mcu->both = rising & falling;
709 	mcu->is_cached &= mcu->both;
710 
711 unlock:
712 	mutex_unlock(&mcu->lock);
713 }
714 
715 static const struct irq_chip omnia_mcu_irq_chip = {
716 	.name			= "Turris Omnia MCU interrupts",
717 	.irq_shutdown		= omnia_irq_shutdown,
718 	.irq_mask		= omnia_irq_mask,
719 	.irq_unmask		= omnia_irq_unmask,
720 	.irq_set_type		= omnia_irq_set_type,
721 	.irq_bus_lock		= omnia_irq_bus_lock,
722 	.irq_bus_sync_unlock	= omnia_irq_bus_sync_unlock,
723 	.flags			= IRQCHIP_IMMUTABLE,
724 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
725 };
726 
727 static void omnia_irq_init_valid_mask(struct gpio_chip *gc,
728 				      unsigned long *valid_mask,
729 				      unsigned int ngpios)
730 {
731 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
732 
733 	for (unsigned int i = 0; i < ngpios; i++) {
734 		const struct omnia_gpio *gpio = &omnia_gpios[i];
735 
736 		if (is_int_bit_valid(gpio))
737 			__assign_bit(i, valid_mask,
738 				     omnia_gpio_available(mcu, gpio));
739 		else
740 			__clear_bit(i, valid_mask);
741 	}
742 }
743 
744 static int omnia_irq_init_hw(struct gpio_chip *gc)
745 {
746 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
747 	u8 cmd[1 + OMNIA_CMD_INT_ARG_LEN] = {};
748 
749 	cmd[0] = OMNIA_CMD_SET_INT_MASK;
750 
751 	return omnia_cmd_write(mcu->client, cmd, sizeof(cmd));
752 }
753 
754 /*
755  * Determine how many bytes we need to read from the reply to the
756  * OMNIA_CMD_GET_INT_AND_CLEAR command in order to retrieve all unmasked
757  * interrupts.
758  */
759 static unsigned int
760 omnia_irq_compute_pending_length(unsigned long rising, unsigned long falling)
761 {
762 	return max(omnia_compute_reply_length(rising, true, 0),
763 		   omnia_compute_reply_length(falling, true, 1));
764 }
765 
766 static bool omnia_irq_read_pending_new(struct omnia_mcu *mcu,
767 				       unsigned long *pending)
768 {
769 	struct device *dev = &mcu->client->dev;
770 	u8 reply[OMNIA_CMD_INT_ARG_LEN] = {};
771 	unsigned long rising, falling;
772 	unsigned int len;
773 	int err;
774 
775 	len = omnia_irq_compute_pending_length(mcu->rising & mcu->mask,
776 					       mcu->falling & mcu->mask);
777 	if (!len)
778 		return false;
779 
780 	guard(mutex)(&mcu->lock);
781 
782 	err = omnia_cmd_read(mcu->client, OMNIA_CMD_GET_INT_AND_CLEAR, reply,
783 			     len);
784 	if (err) {
785 		dev_err(dev, "Cannot read pending IRQs: %d\n", err);
786 		return false;
787 	}
788 
789 	/* deinterleave the reply bytes into rising and falling */
790 	omnia_mask_deinterleave(reply, &rising, &falling);
791 
792 	rising &= mcu->mask;
793 	falling &= mcu->mask;
794 	*pending = rising | falling;
795 
796 	/* cache values for GPIOs that have both edges enabled */
797 	mcu->is_cached &= ~(rising & falling);
798 	mcu->is_cached |= mcu->both & (rising ^ falling);
799 	mcu->cached = (mcu->cached | rising) & ~falling;
800 
801 	return true;
802 }
803 
804 static int omnia_read_status_word_old_fw(struct omnia_mcu *mcu,
805 					 unsigned long *status)
806 {
807 	u16 raw_status;
808 	int err;
809 
810 	err = omnia_cmd_read_u16(mcu->client, OMNIA_CMD_GET_STATUS_WORD,
811 				 &raw_status);
812 	if (err)
813 		return err;
814 
815 	/*
816 	 * Old firmware has a bug wherein it never resets the USB port
817 	 * overcurrent bits back to zero. Ignore them.
818 	 */
819 	*status = raw_status & ~(OMNIA_STS_USB30_OVC | OMNIA_STS_USB31_OVC);
820 
821 	return 0;
822 }
823 
824 static void button_release_emul_fn(struct work_struct *work)
825 {
826 	struct omnia_mcu *mcu = container_of(to_delayed_work(work),
827 					     struct omnia_mcu,
828 					     button_release_emul_work);
829 
830 	mcu->button_pressed_emul = false;
831 	generic_handle_irq_safe(mcu->client->irq);
832 }
833 
834 static void
835 fill_int_from_sts(unsigned long *rising, unsigned long *falling,
836 		  unsigned long rising_sts, unsigned long falling_sts,
837 		  unsigned long sts_bit, unsigned long int_bit)
838 {
839 	if (rising_sts & sts_bit)
840 		*rising |= int_bit;
841 	if (falling_sts & sts_bit)
842 		*falling |= int_bit;
843 }
844 
845 static bool omnia_irq_read_pending_old(struct omnia_mcu *mcu,
846 				       unsigned long *pending)
847 {
848 	unsigned long status, rising_sts, falling_sts, rising, falling;
849 	struct device *dev = &mcu->client->dev;
850 	int err;
851 
852 	guard(mutex)(&mcu->lock);
853 
854 	err = omnia_read_status_word_old_fw(mcu, &status);
855 	if (err) {
856 		dev_err(dev, "Cannot read pending IRQs: %d\n", err);
857 		return false;
858 	}
859 
860 	/*
861 	 * The old firmware triggers an interrupt whenever status word changes,
862 	 * but does not inform about which bits rose or fell. We need to compute
863 	 * this here by comparing with the last status word value.
864 	 *
865 	 * The OMNIA_STS_BUTTON_PRESSED bit needs special handling, because the
866 	 * old firmware clears the OMNIA_STS_BUTTON_PRESSED bit on successful
867 	 * completion of the OMNIA_CMD_GET_STATUS_WORD command, resulting in
868 	 * another interrupt:
869 	 * - first we get an interrupt, we read the status word where
870 	 *   OMNIA_STS_BUTTON_PRESSED is present,
871 	 * - MCU clears the OMNIA_STS_BUTTON_PRESSED bit because we read the
872 	 *   status word,
873 	 * - we get another interrupt because the status word changed again
874 	 *   (the OMNIA_STS_BUTTON_PRESSED bit was cleared).
875 	 *
876 	 * The gpiolib-cdev, gpiolib-sysfs and gpio-keys input driver all call
877 	 * the gpiochip's .get() method after an edge event on a requested GPIO
878 	 * occurs.
879 	 *
880 	 * We ensure that the .get() method reads 1 for the button GPIO for some
881 	 * time.
882 	 */
883 
884 	if (status & OMNIA_STS_BUTTON_PRESSED) {
885 		mcu->button_pressed_emul = true;
886 		mod_delayed_work(system_wq, &mcu->button_release_emul_work,
887 				 msecs_to_jiffies(FRONT_BUTTON_RELEASE_DELAY_MS));
888 	} else if (mcu->button_pressed_emul) {
889 		status |= OMNIA_STS_BUTTON_PRESSED;
890 	}
891 
892 	rising_sts = ~mcu->last_status & status;
893 	falling_sts = mcu->last_status & ~status;
894 
895 	mcu->last_status = status;
896 
897 	/*
898 	 * Fill in the relevant interrupt bits from status bits for CARD_DET,
899 	 * MSATA_IND and BUTTON_PRESSED.
900 	 */
901 	rising = 0;
902 	falling = 0;
903 	fill_int_from_sts(&rising, &falling, rising_sts, falling_sts,
904 			  OMNIA_STS_CARD_DET, OMNIA_INT_CARD_DET);
905 	fill_int_from_sts(&rising, &falling, rising_sts, falling_sts,
906 			  OMNIA_STS_MSATA_IND, OMNIA_INT_MSATA_IND);
907 	fill_int_from_sts(&rising, &falling, rising_sts, falling_sts,
908 			  OMNIA_STS_BUTTON_PRESSED, OMNIA_INT_BUTTON_PRESSED);
909 
910 	/* Use only bits that are enabled */
911 	rising &= mcu->rising & mcu->mask;
912 	falling &= mcu->falling & mcu->mask;
913 	*pending = rising | falling;
914 
915 	return true;
916 }
917 
918 static bool omnia_irq_read_pending(struct omnia_mcu *mcu,
919 				   unsigned long *pending)
920 {
921 	if (mcu->features & OMNIA_FEAT_NEW_INT_API)
922 		return omnia_irq_read_pending_new(mcu, pending);
923 	else
924 		return omnia_irq_read_pending_old(mcu, pending);
925 }
926 
927 static irqreturn_t omnia_irq_thread_handler(int irq, void *dev_id)
928 {
929 	struct omnia_mcu *mcu = dev_id;
930 	struct irq_domain *domain;
931 	unsigned long pending;
932 	unsigned int i;
933 
934 	if (!omnia_irq_read_pending(mcu, &pending))
935 		return IRQ_NONE;
936 
937 	domain = mcu->gc.irq.domain;
938 
939 	for_each_set_bit(i, &pending, 32) {
940 		unsigned int nested_irq;
941 
942 		nested_irq = irq_find_mapping(domain, omnia_int_to_gpio_idx[i]);
943 
944 		handle_nested_irq(nested_irq);
945 	}
946 
947 	return IRQ_RETVAL(pending);
948 }
949 
950 static const char * const front_button_modes[] = { "mcu", "cpu" };
951 
952 static ssize_t front_button_mode_show(struct device *dev,
953 				      struct device_attribute *a, char *buf)
954 {
955 	struct omnia_mcu *mcu = dev_get_drvdata(dev);
956 	int val;
957 
958 	if (mcu->features & OMNIA_FEAT_NEW_INT_API) {
959 		val = omnia_cmd_read_bit(mcu->client, OMNIA_CMD_GET_STATUS_WORD,
960 					 OMNIA_STS_BUTTON_MODE);
961 		if (val < 0)
962 			return val;
963 	} else {
964 		val = !!(mcu->last_status & OMNIA_STS_BUTTON_MODE);
965 	}
966 
967 	return sysfs_emit(buf, "%s\n", front_button_modes[val]);
968 }
969 
970 static ssize_t front_button_mode_store(struct device *dev,
971 				       struct device_attribute *a,
972 				       const char *buf, size_t count)
973 {
974 	struct omnia_mcu *mcu = dev_get_drvdata(dev);
975 	int err, i;
976 
977 	i = sysfs_match_string(front_button_modes, buf);
978 	if (i < 0)
979 		return i;
980 
981 	err = omnia_ctl_cmd_locked(mcu, OMNIA_CMD_GENERAL_CONTROL,
982 				   i ? OMNIA_CTL_BUTTON_MODE : 0,
983 				   OMNIA_CTL_BUTTON_MODE);
984 	if (err)
985 		return err;
986 
987 	return count;
988 }
989 static DEVICE_ATTR_RW(front_button_mode);
990 
991 static struct attribute *omnia_mcu_gpio_attrs[] = {
992 	&dev_attr_front_button_mode.attr,
993 	NULL
994 };
995 
996 const struct attribute_group omnia_mcu_gpio_group = {
997 	.attrs = omnia_mcu_gpio_attrs,
998 };
999 
1000 int omnia_mcu_register_gpiochip(struct omnia_mcu *mcu)
1001 {
1002 	bool new_api = mcu->features & OMNIA_FEAT_NEW_INT_API;
1003 	struct device *dev = &mcu->client->dev;
1004 	unsigned long irqflags;
1005 	int err;
1006 
1007 	err = devm_mutex_init(dev, &mcu->lock);
1008 	if (err)
1009 		return err;
1010 
1011 	mcu->gc.request = omnia_gpio_request;
1012 	mcu->gc.get_direction = omnia_gpio_get_direction;
1013 	mcu->gc.direction_input = omnia_gpio_direction_input;
1014 	mcu->gc.direction_output = omnia_gpio_direction_output;
1015 	mcu->gc.get = omnia_gpio_get;
1016 	mcu->gc.get_multiple = omnia_gpio_get_multiple;
1017 	mcu->gc.set = omnia_gpio_set;
1018 	mcu->gc.set_multiple = omnia_gpio_set_multiple;
1019 	mcu->gc.init_valid_mask = omnia_gpio_init_valid_mask;
1020 	mcu->gc.can_sleep = true;
1021 	mcu->gc.names = omnia_mcu_gpio_templates;
1022 	mcu->gc.base = -1;
1023 	mcu->gc.ngpio = ARRAY_SIZE(omnia_gpios);
1024 	mcu->gc.label = "Turris Omnia MCU GPIOs";
1025 	mcu->gc.parent = dev;
1026 	mcu->gc.owner = THIS_MODULE;
1027 	mcu->gc.of_gpio_n_cells = 3;
1028 	mcu->gc.of_xlate = omnia_gpio_of_xlate;
1029 
1030 	gpio_irq_chip_set_chip(&mcu->gc.irq, &omnia_mcu_irq_chip);
1031 	/* This will let us handle the parent IRQ in the driver */
1032 	mcu->gc.irq.parent_handler = NULL;
1033 	mcu->gc.irq.num_parents = 0;
1034 	mcu->gc.irq.parents = NULL;
1035 	mcu->gc.irq.default_type = IRQ_TYPE_NONE;
1036 	mcu->gc.irq.handler = handle_bad_irq;
1037 	mcu->gc.irq.threaded = true;
1038 	if (new_api)
1039 		mcu->gc.irq.init_hw = omnia_irq_init_hw;
1040 	mcu->gc.irq.init_valid_mask = omnia_irq_init_valid_mask;
1041 
1042 	err = devm_gpiochip_add_data(dev, &mcu->gc, mcu);
1043 	if (err)
1044 		return dev_err_probe(dev, err, "Cannot add GPIO chip\n");
1045 
1046 	/*
1047 	 * Before requesting the interrupt, if firmware does not support the new
1048 	 * interrupt API, we need to cache the value of the status word, so that
1049 	 * when it changes, we may compare the new value with the cached one in
1050 	 * the interrupt handler.
1051 	 */
1052 	if (!new_api) {
1053 		err = omnia_read_status_word_old_fw(mcu, &mcu->last_status);
1054 		if (err)
1055 			return dev_err_probe(dev, err,
1056 					     "Cannot read status word\n");
1057 
1058 		INIT_DELAYED_WORK(&mcu->button_release_emul_work,
1059 				  button_release_emul_fn);
1060 	}
1061 
1062 	irqflags = IRQF_ONESHOT;
1063 	if (new_api)
1064 		irqflags |= IRQF_TRIGGER_LOW;
1065 	else
1066 		irqflags |= IRQF_TRIGGER_FALLING;
1067 
1068 	err = devm_request_threaded_irq(dev, mcu->client->irq, NULL,
1069 					omnia_irq_thread_handler, irqflags,
1070 					"turris-omnia-mcu", mcu);
1071 	if (err)
1072 		return dev_err_probe(dev, err, "Cannot request IRQ\n");
1073 
1074 	if (!new_api) {
1075 		/*
1076 		 * The button_release_emul_work has to be initialized before the
1077 		 * thread is requested, and on driver remove it needs to be
1078 		 * canceled before the thread is freed. Therefore we can't use
1079 		 * devm_delayed_work_autocancel() directly, because the order
1080 		 *   devm_delayed_work_autocancel();
1081 		 *   devm_request_threaded_irq();
1082 		 * would cause improper release order:
1083 		 *   free_irq();
1084 		 *   cancel_delayed_work_sync();
1085 		 * Instead we first initialize the work above, and only now
1086 		 * after IRQ is requested we add the work devm action.
1087 		 */
1088 		err = devm_add_action(dev, devm_delayed_work_drop,
1089 				      &mcu->button_release_emul_work);
1090 		if (err)
1091 			return err;
1092 	}
1093 
1094 	return 0;
1095 }
1096