xref: /linux/drivers/platform/cznic/turris-omnia-mcu-gpio.c (revision 297d9111e9fcf47dd1dcc6f79bba915f35378d01)
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/consumer.h>
17 #include <linux/gpio/driver.h>
18 #include <linux/i2c.h>
19 #include <linux/interrupt.h>
20 #include <linux/mutex.h>
21 #include <linux/sysfs.h>
22 #include <linux/types.h>
23 #include <linux/workqueue.h>
24 #include <linux/unaligned.h>
25 
26 #include <linux/turris-omnia-mcu-interface.h>
27 #include "turris-omnia-mcu.h"
28 
29 #define OMNIA_CMD_INT_ARG_LEN		8
30 #define FRONT_BUTTON_RELEASE_DELAY_MS	50
31 
32 static const char * const omnia_mcu_gpio_names[64] = {
33 	/* GPIOs with value read from the 16-bit wide status */
34 	[4]  = "MiniPCIe0 Card Detect",
35 	[5]  = "MiniPCIe0 mSATA Indicator",
36 	[6]  = "Front USB3 port over-current",
37 	[7]  = "Rear USB3 port over-current",
38 	[8]  = "Front USB3 port power",
39 	[9]  = "Rear USB3 port power",
40 	[12] = "Front Button",
41 
42 	/* GPIOs with value read from the 32-bit wide extended status */
43 	[16] = "SFP nDET",
44 	[28] = "MiniPCIe0 LED",
45 	[29] = "MiniPCIe1 LED",
46 	[30] = "MiniPCIe2 LED",
47 	[31] = "MiniPCIe0 PAN LED",
48 	[32] = "MiniPCIe1 PAN LED",
49 	[33] = "MiniPCIe2 PAN LED",
50 	[34] = "WAN PHY LED0",
51 	[35] = "WAN PHY LED1",
52 	[36] = "LAN switch p0 LED0",
53 	[37] = "LAN switch p0 LED1",
54 	[38] = "LAN switch p1 LED0",
55 	[39] = "LAN switch p1 LED1",
56 	[40] = "LAN switch p2 LED0",
57 	[41] = "LAN switch p2 LED1",
58 	[42] = "LAN switch p3 LED0",
59 	[43] = "LAN switch p3 LED1",
60 	[44] = "LAN switch p4 LED0",
61 	[45] = "LAN switch p4 LED1",
62 	[46] = "LAN switch p5 LED0",
63 	[47] = "LAN switch p5 LED1",
64 
65 	/* GPIOs with value read from the 16-bit wide extended control status */
66 	[48] = "eMMC nRESET",
67 	[49] = "LAN switch nRESET",
68 	[50] = "WAN PHY nRESET",
69 	[51] = "MiniPCIe0 nPERST",
70 	[52] = "MiniPCIe1 nPERST",
71 	[53] = "MiniPCIe2 nPERST",
72 	[54] = "WAN PHY SFP mux",
73 	[56] = "VHV power disable",
74 };
75 
76 struct omnia_gpio {
77 	u8 cmd;
78 	u8 ctl_cmd;
79 	u8 bit;
80 	u8 ctl_bit;
81 	u8 int_bit;
82 	u16 feat;
83 	u16 feat_mask;
84 };
85 
86 #define OMNIA_GPIO_INVALID_INT_BIT	0xff
87 
88 #define _DEF_GPIO(_cmd, _ctl_cmd, _bit, _ctl_bit, _int_bit, _feat, _feat_mask) \
89 	{								\
90 		.cmd = _cmd,						\
91 		.ctl_cmd = _ctl_cmd,					\
92 		.bit = _bit,						\
93 		.ctl_bit = _ctl_bit,					\
94 		.int_bit = (_int_bit) < 0 ? OMNIA_GPIO_INVALID_INT_BIT	\
95 					  : (_int_bit),			\
96 		.feat = _feat,						\
97 		.feat_mask = _feat_mask,				\
98 	}
99 
100 #define _DEF_GPIO_STS(_name) \
101 	_DEF_GPIO(OMNIA_CMD_GET_STATUS_WORD, 0, __bf_shf(OMNIA_STS_ ## _name), \
102 		  0, __bf_shf(OMNIA_INT_ ## _name), 0, 0)
103 
104 #define _DEF_GPIO_CTL(_name) \
105 	_DEF_GPIO(OMNIA_CMD_GET_STATUS_WORD, OMNIA_CMD_GENERAL_CONTROL, \
106 		  __bf_shf(OMNIA_STS_ ## _name), __bf_shf(OMNIA_CTL_ ## _name), \
107 		  -1, 0, 0)
108 
109 #define _DEF_GPIO_EXT_STS(_name, _feat) \
110 	_DEF_GPIO(OMNIA_CMD_GET_EXT_STATUS_DWORD, 0, \
111 		  __bf_shf(OMNIA_EXT_STS_ ## _name), 0, \
112 		  __bf_shf(OMNIA_INT_ ## _name), \
113 		  OMNIA_FEAT_ ## _feat | OMNIA_FEAT_EXT_CMDS, \
114 		  OMNIA_FEAT_ ## _feat | OMNIA_FEAT_EXT_CMDS)
115 
116 #define _DEF_GPIO_EXT_STS_LED(_name, _ledext) \
117 	_DEF_GPIO(OMNIA_CMD_GET_EXT_STATUS_DWORD, 0, \
118 		  __bf_shf(OMNIA_EXT_STS_ ## _name), 0, \
119 		  __bf_shf(OMNIA_INT_ ## _name), \
120 		  OMNIA_FEAT_LED_STATE_ ## _ledext, \
121 		  OMNIA_FEAT_LED_STATE_EXT_MASK)
122 
123 #define _DEF_GPIO_EXT_STS_LEDALL(_name) \
124 	_DEF_GPIO(OMNIA_CMD_GET_EXT_STATUS_DWORD, 0, \
125 		  __bf_shf(OMNIA_EXT_STS_ ## _name), 0, \
126 		  __bf_shf(OMNIA_INT_ ## _name), \
127 		  OMNIA_FEAT_LED_STATE_EXT_MASK, 0)
128 
129 #define _DEF_GPIO_EXT_CTL(_name, _feat) \
130 	_DEF_GPIO(OMNIA_CMD_GET_EXT_CONTROL_STATUS, OMNIA_CMD_EXT_CONTROL, \
131 		  __bf_shf(OMNIA_EXT_CTL_ ## _name), \
132 		  __bf_shf(OMNIA_EXT_CTL_ ## _name), -1, \
133 		  OMNIA_FEAT_ ## _feat | OMNIA_FEAT_EXT_CMDS, \
134 		  OMNIA_FEAT_ ## _feat | OMNIA_FEAT_EXT_CMDS)
135 
136 #define _DEF_INT(_name) \
137 	_DEF_GPIO(0, 0, 0, 0, __bf_shf(OMNIA_INT_ ## _name), 0, 0)
138 
is_int_bit_valid(const struct omnia_gpio * gpio)139 static inline bool is_int_bit_valid(const struct omnia_gpio *gpio)
140 {
141 	return gpio->int_bit != OMNIA_GPIO_INVALID_INT_BIT;
142 }
143 
144 static const struct omnia_gpio omnia_gpios[64] = {
145 	/* GPIOs with value read from the 16-bit wide status */
146 	[4]  = _DEF_GPIO_STS(CARD_DET),
147 	[5]  = _DEF_GPIO_STS(MSATA_IND),
148 	[6]  = _DEF_GPIO_STS(USB30_OVC),
149 	[7]  = _DEF_GPIO_STS(USB31_OVC),
150 	[8]  = _DEF_GPIO_CTL(USB30_PWRON),
151 	[9]  = _DEF_GPIO_CTL(USB31_PWRON),
152 
153 	/* brightness changed interrupt, no GPIO */
154 	[11] = _DEF_INT(BRIGHTNESS_CHANGED),
155 
156 	[12] = _DEF_GPIO_STS(BUTTON_PRESSED),
157 
158 	/* TRNG interrupt, no GPIO */
159 	[13] = _DEF_INT(TRNG),
160 
161 	/* MESSAGE_SIGNED interrupt, no GPIO */
162 	[14] = _DEF_INT(MESSAGE_SIGNED),
163 
164 	/* GPIOs with value read from the 32-bit wide extended status */
165 	[16] = _DEF_GPIO_EXT_STS(SFP_nDET, PERIPH_MCU),
166 	[28] = _DEF_GPIO_EXT_STS_LEDALL(WLAN0_MSATA_LED),
167 	[29] = _DEF_GPIO_EXT_STS_LEDALL(WLAN1_LED),
168 	[30] = _DEF_GPIO_EXT_STS_LEDALL(WLAN2_LED),
169 	[31] = _DEF_GPIO_EXT_STS_LED(WPAN0_LED, EXT),
170 	[32] = _DEF_GPIO_EXT_STS_LED(WPAN1_LED, EXT),
171 	[33] = _DEF_GPIO_EXT_STS_LED(WPAN2_LED, EXT),
172 	[34] = _DEF_GPIO_EXT_STS_LEDALL(WAN_LED0),
173 	[35] = _DEF_GPIO_EXT_STS_LED(WAN_LED1, EXT_V32),
174 	[36] = _DEF_GPIO_EXT_STS_LEDALL(LAN0_LED0),
175 	[37] = _DEF_GPIO_EXT_STS_LEDALL(LAN0_LED1),
176 	[38] = _DEF_GPIO_EXT_STS_LEDALL(LAN1_LED0),
177 	[39] = _DEF_GPIO_EXT_STS_LEDALL(LAN1_LED1),
178 	[40] = _DEF_GPIO_EXT_STS_LEDALL(LAN2_LED0),
179 	[41] = _DEF_GPIO_EXT_STS_LEDALL(LAN2_LED1),
180 	[42] = _DEF_GPIO_EXT_STS_LEDALL(LAN3_LED0),
181 	[43] = _DEF_GPIO_EXT_STS_LEDALL(LAN3_LED1),
182 	[44] = _DEF_GPIO_EXT_STS_LEDALL(LAN4_LED0),
183 	[45] = _DEF_GPIO_EXT_STS_LEDALL(LAN4_LED1),
184 	[46] = _DEF_GPIO_EXT_STS_LEDALL(LAN5_LED0),
185 	[47] = _DEF_GPIO_EXT_STS_LEDALL(LAN5_LED1),
186 
187 	/* GPIOs with value read from the 16-bit wide extended control status */
188 	[48] = _DEF_GPIO_EXT_CTL(nRES_MMC, PERIPH_MCU),
189 	[49] = _DEF_GPIO_EXT_CTL(nRES_LAN, PERIPH_MCU),
190 	[50] = _DEF_GPIO_EXT_CTL(nRES_PHY, PERIPH_MCU),
191 	[51] = _DEF_GPIO_EXT_CTL(nPERST0, PERIPH_MCU),
192 	[52] = _DEF_GPIO_EXT_CTL(nPERST1, PERIPH_MCU),
193 	[53] = _DEF_GPIO_EXT_CTL(nPERST2, PERIPH_MCU),
194 	[54] = _DEF_GPIO_EXT_CTL(PHY_SFP, PERIPH_MCU),
195 	[56] = _DEF_GPIO_EXT_CTL(nVHV_CTRL, PERIPH_MCU),
196 };
197 
198 /* mapping from interrupts to indexes of GPIOs in the omnia_gpios array */
199 static const u8 omnia_int_to_gpio_idx[32] = {
200 	[__bf_shf(OMNIA_INT_CARD_DET)]			= 4,
201 	[__bf_shf(OMNIA_INT_MSATA_IND)]			= 5,
202 	[__bf_shf(OMNIA_INT_USB30_OVC)]			= 6,
203 	[__bf_shf(OMNIA_INT_USB31_OVC)]			= 7,
204 	[__bf_shf(OMNIA_INT_BUTTON_PRESSED)]		= 12,
205 	[__bf_shf(OMNIA_INT_TRNG)]			= 13,
206 	[__bf_shf(OMNIA_INT_MESSAGE_SIGNED)]		= 14,
207 	[__bf_shf(OMNIA_INT_SFP_nDET)]			= 16,
208 	[__bf_shf(OMNIA_INT_BRIGHTNESS_CHANGED)]	= 11,
209 	[__bf_shf(OMNIA_INT_WLAN0_MSATA_LED)]		= 28,
210 	[__bf_shf(OMNIA_INT_WLAN1_LED)]			= 29,
211 	[__bf_shf(OMNIA_INT_WLAN2_LED)]			= 30,
212 	[__bf_shf(OMNIA_INT_WPAN0_LED)]			= 31,
213 	[__bf_shf(OMNIA_INT_WPAN1_LED)]			= 32,
214 	[__bf_shf(OMNIA_INT_WPAN2_LED)]			= 33,
215 	[__bf_shf(OMNIA_INT_WAN_LED0)]			= 34,
216 	[__bf_shf(OMNIA_INT_WAN_LED1)]			= 35,
217 	[__bf_shf(OMNIA_INT_LAN0_LED0)]			= 36,
218 	[__bf_shf(OMNIA_INT_LAN0_LED1)]			= 37,
219 	[__bf_shf(OMNIA_INT_LAN1_LED0)]			= 38,
220 	[__bf_shf(OMNIA_INT_LAN1_LED1)]			= 39,
221 	[__bf_shf(OMNIA_INT_LAN2_LED0)]			= 40,
222 	[__bf_shf(OMNIA_INT_LAN2_LED1)]			= 41,
223 	[__bf_shf(OMNIA_INT_LAN3_LED0)]			= 42,
224 	[__bf_shf(OMNIA_INT_LAN3_LED1)]			= 43,
225 	[__bf_shf(OMNIA_INT_LAN4_LED0)]			= 44,
226 	[__bf_shf(OMNIA_INT_LAN4_LED1)]			= 45,
227 	[__bf_shf(OMNIA_INT_LAN5_LED0)]			= 46,
228 	[__bf_shf(OMNIA_INT_LAN5_LED1)]			= 47,
229 };
230 
231 /* index of PHY_SFP GPIO in the omnia_gpios array */
232 #define OMNIA_GPIO_PHY_SFP_OFFSET	54
233 
omnia_ctl_cmd_locked(struct omnia_mcu * mcu,u8 cmd,u16 val,u16 mask)234 static int omnia_ctl_cmd_locked(struct omnia_mcu *mcu, u8 cmd, u16 val, u16 mask)
235 {
236 	unsigned int len;
237 	u8 buf[5];
238 
239 	buf[0] = cmd;
240 
241 	switch (cmd) {
242 	case OMNIA_CMD_GENERAL_CONTROL:
243 		buf[1] = val;
244 		buf[2] = mask;
245 		len = 3;
246 		break;
247 
248 	case OMNIA_CMD_EXT_CONTROL:
249 		put_unaligned_le16(val, &buf[1]);
250 		put_unaligned_le16(mask, &buf[3]);
251 		len = 5;
252 		break;
253 
254 	default:
255 		BUG();
256 	}
257 
258 	return omnia_cmd_write(mcu->client, buf, len);
259 }
260 
omnia_ctl_cmd(struct omnia_mcu * mcu,u8 cmd,u16 val,u16 mask)261 static int omnia_ctl_cmd(struct omnia_mcu *mcu, u8 cmd, u16 val, u16 mask)
262 {
263 	guard(mutex)(&mcu->lock);
264 
265 	return omnia_ctl_cmd_locked(mcu, cmd, val, mask);
266 }
267 
omnia_gpio_request(struct gpio_chip * gc,unsigned int offset)268 static int omnia_gpio_request(struct gpio_chip *gc, unsigned int offset)
269 {
270 	if (!omnia_gpios[offset].cmd)
271 		return -EINVAL;
272 
273 	return 0;
274 }
275 
omnia_gpio_get_direction(struct gpio_chip * gc,unsigned int offset)276 static int omnia_gpio_get_direction(struct gpio_chip *gc, unsigned int offset)
277 {
278 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
279 
280 	if (offset == OMNIA_GPIO_PHY_SFP_OFFSET) {
281 		int val;
282 
283 		scoped_guard(mutex, &mcu->lock) {
284 			val = omnia_cmd_read_bit(mcu->client,
285 						 OMNIA_CMD_GET_EXT_CONTROL_STATUS,
286 						 OMNIA_EXT_CTL_PHY_SFP_AUTO);
287 			if (val < 0)
288 				return val;
289 		}
290 
291 		if (val)
292 			return GPIO_LINE_DIRECTION_IN;
293 
294 		return GPIO_LINE_DIRECTION_OUT;
295 	}
296 
297 	if (omnia_gpios[offset].ctl_cmd)
298 		return GPIO_LINE_DIRECTION_OUT;
299 
300 	return GPIO_LINE_DIRECTION_IN;
301 }
302 
omnia_gpio_direction_input(struct gpio_chip * gc,unsigned int offset)303 static int omnia_gpio_direction_input(struct gpio_chip *gc, unsigned int offset)
304 {
305 	const struct omnia_gpio *gpio = &omnia_gpios[offset];
306 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
307 
308 	if (offset == OMNIA_GPIO_PHY_SFP_OFFSET)
309 		return omnia_ctl_cmd(mcu, OMNIA_CMD_EXT_CONTROL,
310 				     OMNIA_EXT_CTL_PHY_SFP_AUTO,
311 				     OMNIA_EXT_CTL_PHY_SFP_AUTO);
312 
313 	if (gpio->ctl_cmd)
314 		return -ENOTSUPP;
315 
316 	return 0;
317 }
318 
omnia_gpio_direction_output(struct gpio_chip * gc,unsigned int offset,int value)319 static int omnia_gpio_direction_output(struct gpio_chip *gc,
320 				       unsigned int offset, int value)
321 {
322 	const struct omnia_gpio *gpio = &omnia_gpios[offset];
323 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
324 	u16 val, mask;
325 
326 	if (!gpio->ctl_cmd)
327 		return -ENOTSUPP;
328 
329 	mask = BIT(gpio->ctl_bit);
330 	val = value ? mask : 0;
331 
332 	if (offset == OMNIA_GPIO_PHY_SFP_OFFSET)
333 		mask |= OMNIA_EXT_CTL_PHY_SFP_AUTO;
334 
335 	return omnia_ctl_cmd(mcu, gpio->ctl_cmd, val, mask);
336 }
337 
omnia_gpio_get(struct gpio_chip * gc,unsigned int offset)338 static int omnia_gpio_get(struct gpio_chip *gc, unsigned int offset)
339 {
340 	const struct omnia_gpio *gpio = &omnia_gpios[offset];
341 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
342 
343 	/*
344 	 * If firmware does not support the new interrupt API, we are informed
345 	 * of every change of the status word by an interrupt from MCU and save
346 	 * its value in the interrupt service routine. Simply return the saved
347 	 * value.
348 	 */
349 	if (gpio->cmd == OMNIA_CMD_GET_STATUS_WORD &&
350 	    !(mcu->features & OMNIA_FEAT_NEW_INT_API))
351 		return test_bit(gpio->bit, &mcu->last_status);
352 
353 	guard(mutex)(&mcu->lock);
354 
355 	/*
356 	 * If firmware does support the new interrupt API, we may have cached
357 	 * the value of a GPIO in the interrupt service routine. If not, read
358 	 * the relevant bit now.
359 	 */
360 	if (is_int_bit_valid(gpio) && test_bit(gpio->int_bit, &mcu->is_cached))
361 		return test_bit(gpio->int_bit, &mcu->cached);
362 
363 	return omnia_cmd_read_bit(mcu->client, gpio->cmd, BIT(gpio->bit));
364 }
365 
366 static unsigned long *
_relevant_field_for_sts_cmd(u8 cmd,unsigned long * sts,unsigned long * ext_sts,unsigned long * ext_ctl)367 _relevant_field_for_sts_cmd(u8 cmd, unsigned long *sts, unsigned long *ext_sts,
368 			    unsigned long *ext_ctl)
369 {
370 	switch (cmd) {
371 	case OMNIA_CMD_GET_STATUS_WORD:
372 		return sts;
373 	case OMNIA_CMD_GET_EXT_STATUS_DWORD:
374 		return ext_sts;
375 	case OMNIA_CMD_GET_EXT_CONTROL_STATUS:
376 		return ext_ctl;
377 	default:
378 		return NULL;
379 	}
380 }
381 
omnia_gpio_get_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)382 static int omnia_gpio_get_multiple(struct gpio_chip *gc, unsigned long *mask,
383 				   unsigned long *bits)
384 {
385 	unsigned long sts = 0, ext_sts = 0, ext_ctl = 0, *field;
386 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
387 	struct i2c_client *client = mcu->client;
388 	unsigned int i;
389 	int err;
390 
391 	/* determine which bits to read from the 3 possible commands */
392 	for_each_set_bit(i, mask, ARRAY_SIZE(omnia_gpios)) {
393 		field = _relevant_field_for_sts_cmd(omnia_gpios[i].cmd,
394 						    &sts, &ext_sts, &ext_ctl);
395 		if (!field)
396 			continue;
397 
398 		__set_bit(omnia_gpios[i].bit, field);
399 	}
400 
401 	guard(mutex)(&mcu->lock);
402 
403 	if (mcu->features & OMNIA_FEAT_NEW_INT_API) {
404 		/* read relevant bits from status */
405 		err = omnia_cmd_read_bits(client, OMNIA_CMD_GET_STATUS_WORD,
406 					  sts, &sts);
407 		if (err)
408 			return err;
409 	} else {
410 		/*
411 		 * Use status word value cached in the interrupt service routine
412 		 * if firmware does not support the new interrupt API.
413 		 */
414 		sts = mcu->last_status;
415 	}
416 
417 	/* read relevant bits from extended status */
418 	err = omnia_cmd_read_bits(client, OMNIA_CMD_GET_EXT_STATUS_DWORD,
419 				  ext_sts, &ext_sts);
420 	if (err)
421 		return err;
422 
423 	/* read relevant bits from extended control */
424 	err = omnia_cmd_read_bits(client, OMNIA_CMD_GET_EXT_CONTROL_STATUS,
425 				  ext_ctl, &ext_ctl);
426 	if (err)
427 		return err;
428 
429 	/* assign relevant bits in result */
430 	for_each_set_bit(i, mask, ARRAY_SIZE(omnia_gpios)) {
431 		field = _relevant_field_for_sts_cmd(omnia_gpios[i].cmd,
432 						    &sts, &ext_sts, &ext_ctl);
433 		if (!field)
434 			continue;
435 
436 		__assign_bit(i, bits, test_bit(omnia_gpios[i].bit, field));
437 	}
438 
439 	return 0;
440 }
441 
omnia_gpio_set(struct gpio_chip * gc,unsigned int offset,int value)442 static void omnia_gpio_set(struct gpio_chip *gc, unsigned int offset, int value)
443 {
444 	const struct omnia_gpio *gpio = &omnia_gpios[offset];
445 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
446 	u16 val, mask;
447 
448 	if (!gpio->ctl_cmd)
449 		return;
450 
451 	mask = BIT(gpio->ctl_bit);
452 	val = value ? mask : 0;
453 
454 	omnia_ctl_cmd(mcu, gpio->ctl_cmd, val, mask);
455 }
456 
omnia_gpio_set_multiple(struct gpio_chip * gc,unsigned long * mask,unsigned long * bits)457 static void omnia_gpio_set_multiple(struct gpio_chip *gc, unsigned long *mask,
458 				    unsigned long *bits)
459 {
460 	unsigned long ctl = 0, ctl_mask = 0, ext_ctl = 0, ext_ctl_mask = 0;
461 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
462 	unsigned int i;
463 
464 	for_each_set_bit(i, mask, ARRAY_SIZE(omnia_gpios)) {
465 		unsigned long *field, *field_mask;
466 		u8 bit = omnia_gpios[i].ctl_bit;
467 
468 		switch (omnia_gpios[i].ctl_cmd) {
469 		case OMNIA_CMD_GENERAL_CONTROL:
470 			field = &ctl;
471 			field_mask = &ctl_mask;
472 			break;
473 		case OMNIA_CMD_EXT_CONTROL:
474 			field = &ext_ctl;
475 			field_mask = &ext_ctl_mask;
476 			break;
477 		default:
478 			field = field_mask = NULL;
479 			break;
480 		}
481 
482 		if (!field)
483 			continue;
484 
485 		__set_bit(bit, field_mask);
486 		__assign_bit(bit, field, test_bit(i, bits));
487 	}
488 
489 	guard(mutex)(&mcu->lock);
490 
491 	if (ctl_mask)
492 		omnia_ctl_cmd_locked(mcu, OMNIA_CMD_GENERAL_CONTROL,
493 				     ctl, ctl_mask);
494 
495 	if (ext_ctl_mask)
496 		omnia_ctl_cmd_locked(mcu, OMNIA_CMD_EXT_CONTROL,
497 				     ext_ctl, ext_ctl_mask);
498 }
499 
omnia_gpio_available(struct omnia_mcu * mcu,const struct omnia_gpio * gpio)500 static bool omnia_gpio_available(struct omnia_mcu *mcu,
501 				 const struct omnia_gpio *gpio)
502 {
503 	if (gpio->feat_mask)
504 		return (mcu->features & gpio->feat_mask) == gpio->feat;
505 
506 	if (gpio->feat)
507 		return mcu->features & gpio->feat;
508 
509 	return true;
510 }
511 
omnia_gpio_init_valid_mask(struct gpio_chip * gc,unsigned long * valid_mask,unsigned int ngpios)512 static int omnia_gpio_init_valid_mask(struct gpio_chip *gc,
513 				      unsigned long *valid_mask,
514 				      unsigned int ngpios)
515 {
516 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
517 
518 	for (unsigned int i = 0; i < ngpios; i++) {
519 		const struct omnia_gpio *gpio = &omnia_gpios[i];
520 
521 		if (gpio->cmd || is_int_bit_valid(gpio))
522 			__assign_bit(i, valid_mask,
523 				     omnia_gpio_available(mcu, gpio));
524 		else
525 			__clear_bit(i, valid_mask);
526 	}
527 
528 	return 0;
529 }
530 
omnia_gpio_of_xlate(struct gpio_chip * gc,const struct of_phandle_args * gpiospec,u32 * flags)531 static int omnia_gpio_of_xlate(struct gpio_chip *gc,
532 			       const struct of_phandle_args *gpiospec,
533 			       u32 *flags)
534 {
535 	u32 bank, gpio;
536 
537 	if (WARN_ON(gpiospec->args_count != 3))
538 		return -EINVAL;
539 
540 	if (flags)
541 		*flags = gpiospec->args[2];
542 
543 	bank = gpiospec->args[0];
544 	gpio = gpiospec->args[1];
545 
546 	switch (bank) {
547 	case 0:
548 		return gpio < 16 ? gpio : -EINVAL;
549 	case 1:
550 		return gpio < 32 ? 16 + gpio : -EINVAL;
551 	case 2:
552 		return gpio < 16 ? 48 + gpio : -EINVAL;
553 	default:
554 		return -EINVAL;
555 	}
556 }
557 
omnia_irq_shutdown(struct irq_data * d)558 static void omnia_irq_shutdown(struct irq_data *d)
559 {
560 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
561 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
562 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
563 	u8 bit = omnia_gpios[hwirq].int_bit;
564 
565 	__clear_bit(bit, &mcu->rising);
566 	__clear_bit(bit, &mcu->falling);
567 }
568 
omnia_irq_mask(struct irq_data * d)569 static void omnia_irq_mask(struct irq_data *d)
570 {
571 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
572 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
573 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
574 	u8 bit = omnia_gpios[hwirq].int_bit;
575 
576 	if (!omnia_gpios[hwirq].cmd)
577 		__clear_bit(bit, &mcu->rising);
578 	__clear_bit(bit, &mcu->mask);
579 	gpiochip_disable_irq(gc, hwirq);
580 }
581 
omnia_irq_unmask(struct irq_data * d)582 static void omnia_irq_unmask(struct irq_data *d)
583 {
584 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
585 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
586 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
587 	u8 bit = omnia_gpios[hwirq].int_bit;
588 
589 	gpiochip_enable_irq(gc, hwirq);
590 	__set_bit(bit, &mcu->mask);
591 	if (!omnia_gpios[hwirq].cmd)
592 		__set_bit(bit, &mcu->rising);
593 }
594 
omnia_irq_set_type(struct irq_data * d,unsigned int type)595 static int omnia_irq_set_type(struct irq_data *d, unsigned int type)
596 {
597 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
598 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
599 	irq_hw_number_t hwirq = irqd_to_hwirq(d);
600 	struct device *dev = &mcu->client->dev;
601 	u8 bit = omnia_gpios[hwirq].int_bit;
602 
603 	if (!(type & IRQ_TYPE_EDGE_BOTH)) {
604 		dev_err(dev, "irq %u: unsupported type %u\n", d->irq, type);
605 		return -EINVAL;
606 	}
607 
608 	__assign_bit(bit, &mcu->rising, type & IRQ_TYPE_EDGE_RISING);
609 	__assign_bit(bit, &mcu->falling, type & IRQ_TYPE_EDGE_FALLING);
610 
611 	return 0;
612 }
613 
omnia_irq_bus_lock(struct irq_data * d)614 static void omnia_irq_bus_lock(struct irq_data *d)
615 {
616 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
617 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
618 
619 	/* nothing to do if MCU firmware does not support new interrupt API */
620 	if (!(mcu->features & OMNIA_FEAT_NEW_INT_API))
621 		return;
622 
623 	mutex_lock(&mcu->lock);
624 }
625 
626 /**
627  * omnia_mask_interleave - Interleaves the bytes from @rising and @falling
628  * @dst: the destination u8 array of interleaved bytes
629  * @rising: rising mask
630  * @falling: falling mask
631  *
632  * Interleaves the little-endian bytes from @rising and @falling words.
633  *
634  * If @rising = (r0, r1, r2, r3) and @falling = (f0, f1, f2, f3), the result is
635  * @dst = (r0, f0, r1, f1, r2, f2, r3, f3).
636  *
637  * The MCU receives an interrupt mask and reports a pending interrupt bitmap in
638  * this interleaved format. The rationale behind this is that the low-indexed
639  * bits are more important - in many cases, the user will be interested only in
640  * interrupts with indexes 0 to 7, and so the system can stop reading after
641  * first 2 bytes (r0, f0), to save time on the slow I2C bus.
642  *
643  * Feel free to remove this function and its inverse, omnia_mask_deinterleave,
644  * and use an appropriate bitmap_*() function once such a function exists.
645  */
646 static void
omnia_mask_interleave(u8 * dst,unsigned long rising,unsigned long falling)647 omnia_mask_interleave(u8 *dst, unsigned long rising, unsigned long falling)
648 {
649 	for (unsigned int i = 0; i < sizeof(u32); i++) {
650 		dst[2 * i] = rising >> (8 * i);
651 		dst[2 * i + 1] = falling >> (8 * i);
652 	}
653 }
654 
655 /**
656  * omnia_mask_deinterleave - Deinterleaves the bytes into @rising and @falling
657  * @src: the source u8 array containing the interleaved bytes
658  * @rising: pointer where to store the rising mask gathered from @src
659  * @falling: pointer where to store the falling mask gathered from @src
660  *
661  * This is the inverse function to omnia_mask_interleave.
662  */
omnia_mask_deinterleave(const u8 * src,unsigned long * rising,unsigned long * falling)663 static void omnia_mask_deinterleave(const u8 *src, unsigned long *rising,
664 				    unsigned long *falling)
665 {
666 	*rising = *falling = 0;
667 
668 	for (unsigned int i = 0; i < sizeof(u32); i++) {
669 		*rising |= src[2 * i] << (8 * i);
670 		*falling |= src[2 * i + 1] << (8 * i);
671 	}
672 }
673 
omnia_irq_bus_sync_unlock(struct irq_data * d)674 static void omnia_irq_bus_sync_unlock(struct irq_data *d)
675 {
676 	struct gpio_chip *gc = irq_data_get_irq_chip_data(d);
677 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
678 	struct device *dev = &mcu->client->dev;
679 	u8 cmd[1 + OMNIA_CMD_INT_ARG_LEN];
680 	unsigned long rising, falling;
681 	int err;
682 
683 	/* nothing to do if MCU firmware does not support new interrupt API */
684 	if (!(mcu->features & OMNIA_FEAT_NEW_INT_API))
685 		return;
686 
687 	cmd[0] = OMNIA_CMD_SET_INT_MASK;
688 
689 	rising = mcu->rising & mcu->mask;
690 	falling = mcu->falling & mcu->mask;
691 
692 	/* interleave the rising and falling bytes into the command arguments */
693 	omnia_mask_interleave(&cmd[1], rising, falling);
694 
695 	dev_dbg(dev, "set int mask %8ph\n", &cmd[1]);
696 
697 	err = omnia_cmd_write(mcu->client, cmd, sizeof(cmd));
698 	if (err) {
699 		dev_err(dev, "Cannot set mask: %d\n", err);
700 		goto unlock;
701 	}
702 
703 	/*
704 	 * Remember which GPIOs have both rising and falling interrupts enabled.
705 	 * For those we will cache their value so that .get() method is faster.
706 	 * We also need to forget cached values of GPIOs that aren't cached
707 	 * anymore.
708 	 */
709 	mcu->both = rising & falling;
710 	mcu->is_cached &= mcu->both;
711 
712 unlock:
713 	mutex_unlock(&mcu->lock);
714 }
715 
716 static const struct irq_chip omnia_mcu_irq_chip = {
717 	.name			= "Turris Omnia MCU interrupts",
718 	.irq_shutdown		= omnia_irq_shutdown,
719 	.irq_mask		= omnia_irq_mask,
720 	.irq_unmask		= omnia_irq_unmask,
721 	.irq_set_type		= omnia_irq_set_type,
722 	.irq_bus_lock		= omnia_irq_bus_lock,
723 	.irq_bus_sync_unlock	= omnia_irq_bus_sync_unlock,
724 	.flags			= IRQCHIP_IMMUTABLE,
725 	GPIOCHIP_IRQ_RESOURCE_HELPERS,
726 };
727 
omnia_irq_init_valid_mask(struct gpio_chip * gc,unsigned long * valid_mask,unsigned int ngpios)728 static void omnia_irq_init_valid_mask(struct gpio_chip *gc,
729 				      unsigned long *valid_mask,
730 				      unsigned int ngpios)
731 {
732 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
733 
734 	for (unsigned int i = 0; i < ngpios; i++) {
735 		const struct omnia_gpio *gpio = &omnia_gpios[i];
736 
737 		if (is_int_bit_valid(gpio))
738 			__assign_bit(i, valid_mask,
739 				     omnia_gpio_available(mcu, gpio));
740 		else
741 			__clear_bit(i, valid_mask);
742 	}
743 }
744 
omnia_irq_init_hw(struct gpio_chip * gc)745 static int omnia_irq_init_hw(struct gpio_chip *gc)
746 {
747 	struct omnia_mcu *mcu = gpiochip_get_data(gc);
748 	u8 cmd[1 + OMNIA_CMD_INT_ARG_LEN] = {};
749 
750 	cmd[0] = OMNIA_CMD_SET_INT_MASK;
751 
752 	return omnia_cmd_write(mcu->client, cmd, sizeof(cmd));
753 }
754 
755 /*
756  * Determine how many bytes we need to read from the reply to the
757  * OMNIA_CMD_GET_INT_AND_CLEAR command in order to retrieve all unmasked
758  * interrupts.
759  */
760 static unsigned int
omnia_irq_compute_pending_length(unsigned long rising,unsigned long falling)761 omnia_irq_compute_pending_length(unsigned long rising, unsigned long falling)
762 {
763 	return max(omnia_compute_reply_length(rising, true, 0),
764 		   omnia_compute_reply_length(falling, true, 1));
765 }
766 
omnia_irq_read_pending_new(struct omnia_mcu * mcu,unsigned long * pending)767 static bool omnia_irq_read_pending_new(struct omnia_mcu *mcu,
768 				       unsigned long *pending)
769 {
770 	struct device *dev = &mcu->client->dev;
771 	u8 reply[OMNIA_CMD_INT_ARG_LEN] = {};
772 	unsigned long rising, falling;
773 	unsigned int len;
774 	int err;
775 
776 	len = omnia_irq_compute_pending_length(mcu->rising & mcu->mask,
777 					       mcu->falling & mcu->mask);
778 	if (!len)
779 		return false;
780 
781 	guard(mutex)(&mcu->lock);
782 
783 	err = omnia_cmd_read(mcu->client, OMNIA_CMD_GET_INT_AND_CLEAR, reply,
784 			     len);
785 	if (err) {
786 		dev_err(dev, "Cannot read pending IRQs: %d\n", err);
787 		return false;
788 	}
789 
790 	/* deinterleave the reply bytes into rising and falling */
791 	omnia_mask_deinterleave(reply, &rising, &falling);
792 
793 	rising &= mcu->mask;
794 	falling &= mcu->mask;
795 	*pending = rising | falling;
796 
797 	/* cache values for GPIOs that have both edges enabled */
798 	mcu->is_cached &= ~(rising & falling);
799 	mcu->is_cached |= mcu->both & (rising ^ falling);
800 	mcu->cached = (mcu->cached | rising) & ~falling;
801 
802 	return true;
803 }
804 
omnia_read_status_word_old_fw(struct omnia_mcu * mcu,unsigned long * status)805 static int omnia_read_status_word_old_fw(struct omnia_mcu *mcu,
806 					 unsigned long *status)
807 {
808 	u16 raw_status;
809 	int err;
810 
811 	err = omnia_cmd_read_u16(mcu->client, OMNIA_CMD_GET_STATUS_WORD,
812 				 &raw_status);
813 	if (err)
814 		return err;
815 
816 	/*
817 	 * Old firmware has a bug wherein it never resets the USB port
818 	 * overcurrent bits back to zero. Ignore them.
819 	 */
820 	*status = raw_status & ~(OMNIA_STS_USB30_OVC | OMNIA_STS_USB31_OVC);
821 
822 	return 0;
823 }
824 
button_release_emul_fn(struct work_struct * work)825 static void button_release_emul_fn(struct work_struct *work)
826 {
827 	struct omnia_mcu *mcu = container_of(to_delayed_work(work),
828 					     struct omnia_mcu,
829 					     button_release_emul_work);
830 
831 	mcu->button_pressed_emul = false;
832 	generic_handle_irq_safe(mcu->client->irq);
833 }
834 
835 static void
fill_int_from_sts(unsigned long * rising,unsigned long * falling,unsigned long rising_sts,unsigned long falling_sts,unsigned long sts_bit,unsigned long int_bit)836 fill_int_from_sts(unsigned long *rising, unsigned long *falling,
837 		  unsigned long rising_sts, unsigned long falling_sts,
838 		  unsigned long sts_bit, unsigned long int_bit)
839 {
840 	if (rising_sts & sts_bit)
841 		*rising |= int_bit;
842 	if (falling_sts & sts_bit)
843 		*falling |= int_bit;
844 }
845 
omnia_irq_read_pending_old(struct omnia_mcu * mcu,unsigned long * pending)846 static bool omnia_irq_read_pending_old(struct omnia_mcu *mcu,
847 				       unsigned long *pending)
848 {
849 	unsigned long status, rising_sts, falling_sts, rising, falling;
850 	struct device *dev = &mcu->client->dev;
851 	int err;
852 
853 	guard(mutex)(&mcu->lock);
854 
855 	err = omnia_read_status_word_old_fw(mcu, &status);
856 	if (err) {
857 		dev_err(dev, "Cannot read pending IRQs: %d\n", err);
858 		return false;
859 	}
860 
861 	/*
862 	 * The old firmware triggers an interrupt whenever status word changes,
863 	 * but does not inform about which bits rose or fell. We need to compute
864 	 * this here by comparing with the last status word value.
865 	 *
866 	 * The OMNIA_STS_BUTTON_PRESSED bit needs special handling, because the
867 	 * old firmware clears the OMNIA_STS_BUTTON_PRESSED bit on successful
868 	 * completion of the OMNIA_CMD_GET_STATUS_WORD command, resulting in
869 	 * another interrupt:
870 	 * - first we get an interrupt, we read the status word where
871 	 *   OMNIA_STS_BUTTON_PRESSED is present,
872 	 * - MCU clears the OMNIA_STS_BUTTON_PRESSED bit because we read the
873 	 *   status word,
874 	 * - we get another interrupt because the status word changed again
875 	 *   (the OMNIA_STS_BUTTON_PRESSED bit was cleared).
876 	 *
877 	 * The gpiolib-cdev, gpiolib-sysfs and gpio-keys input driver all call
878 	 * the gpiochip's .get() method after an edge event on a requested GPIO
879 	 * occurs.
880 	 *
881 	 * We ensure that the .get() method reads 1 for the button GPIO for some
882 	 * time.
883 	 */
884 
885 	if (status & OMNIA_STS_BUTTON_PRESSED) {
886 		mcu->button_pressed_emul = true;
887 		mod_delayed_work(system_wq, &mcu->button_release_emul_work,
888 				 msecs_to_jiffies(FRONT_BUTTON_RELEASE_DELAY_MS));
889 	} else if (mcu->button_pressed_emul) {
890 		status |= OMNIA_STS_BUTTON_PRESSED;
891 	}
892 
893 	rising_sts = ~mcu->last_status & status;
894 	falling_sts = mcu->last_status & ~status;
895 
896 	mcu->last_status = status;
897 
898 	/*
899 	 * Fill in the relevant interrupt bits from status bits for CARD_DET,
900 	 * MSATA_IND and BUTTON_PRESSED.
901 	 */
902 	rising = 0;
903 	falling = 0;
904 	fill_int_from_sts(&rising, &falling, rising_sts, falling_sts,
905 			  OMNIA_STS_CARD_DET, OMNIA_INT_CARD_DET);
906 	fill_int_from_sts(&rising, &falling, rising_sts, falling_sts,
907 			  OMNIA_STS_MSATA_IND, OMNIA_INT_MSATA_IND);
908 	fill_int_from_sts(&rising, &falling, rising_sts, falling_sts,
909 			  OMNIA_STS_BUTTON_PRESSED, OMNIA_INT_BUTTON_PRESSED);
910 
911 	/* Use only bits that are enabled */
912 	rising &= mcu->rising & mcu->mask;
913 	falling &= mcu->falling & mcu->mask;
914 	*pending = rising | falling;
915 
916 	return true;
917 }
918 
omnia_irq_read_pending(struct omnia_mcu * mcu,unsigned long * pending)919 static bool omnia_irq_read_pending(struct omnia_mcu *mcu,
920 				   unsigned long *pending)
921 {
922 	if (mcu->features & OMNIA_FEAT_NEW_INT_API)
923 		return omnia_irq_read_pending_new(mcu, pending);
924 	else
925 		return omnia_irq_read_pending_old(mcu, pending);
926 }
927 
omnia_irq_thread_handler(int irq,void * dev_id)928 static irqreturn_t omnia_irq_thread_handler(int irq, void *dev_id)
929 {
930 	struct omnia_mcu *mcu = dev_id;
931 	struct irq_domain *domain;
932 	unsigned long pending;
933 	unsigned int i;
934 
935 	if (!omnia_irq_read_pending(mcu, &pending))
936 		return IRQ_NONE;
937 
938 	domain = mcu->gc.irq.domain;
939 
940 	for_each_set_bit(i, &pending, 32) {
941 		unsigned int nested_irq;
942 
943 		nested_irq = irq_find_mapping(domain, omnia_int_to_gpio_idx[i]);
944 
945 		handle_nested_irq(nested_irq);
946 	}
947 
948 	return IRQ_RETVAL(pending);
949 }
950 
951 static const char * const front_button_modes[] = { "mcu", "cpu" };
952 
front_button_mode_show(struct device * dev,struct device_attribute * a,char * buf)953 static ssize_t front_button_mode_show(struct device *dev,
954 				      struct device_attribute *a, char *buf)
955 {
956 	struct omnia_mcu *mcu = dev_get_drvdata(dev);
957 	int val;
958 
959 	if (mcu->features & OMNIA_FEAT_NEW_INT_API) {
960 		val = omnia_cmd_read_bit(mcu->client, OMNIA_CMD_GET_STATUS_WORD,
961 					 OMNIA_STS_BUTTON_MODE);
962 		if (val < 0)
963 			return val;
964 	} else {
965 		val = !!(mcu->last_status & OMNIA_STS_BUTTON_MODE);
966 	}
967 
968 	return sysfs_emit(buf, "%s\n", front_button_modes[val]);
969 }
970 
front_button_mode_store(struct device * dev,struct device_attribute * a,const char * buf,size_t count)971 static ssize_t front_button_mode_store(struct device *dev,
972 				       struct device_attribute *a,
973 				       const char *buf, size_t count)
974 {
975 	struct omnia_mcu *mcu = dev_get_drvdata(dev);
976 	int err, i;
977 
978 	i = sysfs_match_string(front_button_modes, buf);
979 	if (i < 0)
980 		return i;
981 
982 	err = omnia_ctl_cmd_locked(mcu, OMNIA_CMD_GENERAL_CONTROL,
983 				   i ? OMNIA_CTL_BUTTON_MODE : 0,
984 				   OMNIA_CTL_BUTTON_MODE);
985 	if (err)
986 		return err;
987 
988 	return count;
989 }
990 static DEVICE_ATTR_RW(front_button_mode);
991 
992 static struct attribute *omnia_mcu_gpio_attrs[] = {
993 	&dev_attr_front_button_mode.attr,
994 	NULL
995 };
996 
997 const struct attribute_group omnia_mcu_gpio_group = {
998 	.attrs = omnia_mcu_gpio_attrs,
999 };
1000 
omnia_mcu_register_gpiochip(struct omnia_mcu * mcu)1001 int omnia_mcu_register_gpiochip(struct omnia_mcu *mcu)
1002 {
1003 	bool new_api = mcu->features & OMNIA_FEAT_NEW_INT_API;
1004 	struct device *dev = &mcu->client->dev;
1005 	unsigned long irqflags;
1006 	int err;
1007 
1008 	err = devm_mutex_init(dev, &mcu->lock);
1009 	if (err)
1010 		return err;
1011 
1012 	mcu->gc.request = omnia_gpio_request;
1013 	mcu->gc.get_direction = omnia_gpio_get_direction;
1014 	mcu->gc.direction_input = omnia_gpio_direction_input;
1015 	mcu->gc.direction_output = omnia_gpio_direction_output;
1016 	mcu->gc.get = omnia_gpio_get;
1017 	mcu->gc.get_multiple = omnia_gpio_get_multiple;
1018 	mcu->gc.set = omnia_gpio_set;
1019 	mcu->gc.set_multiple = omnia_gpio_set_multiple;
1020 	mcu->gc.init_valid_mask = omnia_gpio_init_valid_mask;
1021 	mcu->gc.can_sleep = true;
1022 	mcu->gc.names = omnia_mcu_gpio_names;
1023 	mcu->gc.base = -1;
1024 	mcu->gc.ngpio = ARRAY_SIZE(omnia_gpios);
1025 	mcu->gc.label = "Turris Omnia MCU GPIOs";
1026 	mcu->gc.parent = dev;
1027 	mcu->gc.owner = THIS_MODULE;
1028 	mcu->gc.of_gpio_n_cells = 3;
1029 	mcu->gc.of_xlate = omnia_gpio_of_xlate;
1030 
1031 	gpio_irq_chip_set_chip(&mcu->gc.irq, &omnia_mcu_irq_chip);
1032 	/* This will let us handle the parent IRQ in the driver */
1033 	mcu->gc.irq.parent_handler = NULL;
1034 	mcu->gc.irq.num_parents = 0;
1035 	mcu->gc.irq.parents = NULL;
1036 	mcu->gc.irq.default_type = IRQ_TYPE_NONE;
1037 	mcu->gc.irq.handler = handle_bad_irq;
1038 	mcu->gc.irq.threaded = true;
1039 	if (new_api)
1040 		mcu->gc.irq.init_hw = omnia_irq_init_hw;
1041 	mcu->gc.irq.init_valid_mask = omnia_irq_init_valid_mask;
1042 
1043 	err = devm_gpiochip_add_data(dev, &mcu->gc, mcu);
1044 	if (err)
1045 		return dev_err_probe(dev, err, "Cannot add GPIO chip\n");
1046 
1047 	/*
1048 	 * Before requesting the interrupt, if firmware does not support the new
1049 	 * interrupt API, we need to cache the value of the status word, so that
1050 	 * when it changes, we may compare the new value with the cached one in
1051 	 * the interrupt handler.
1052 	 */
1053 	if (!new_api) {
1054 		err = omnia_read_status_word_old_fw(mcu, &mcu->last_status);
1055 		if (err)
1056 			return dev_err_probe(dev, err,
1057 					     "Cannot read status word\n");
1058 
1059 		INIT_DELAYED_WORK(&mcu->button_release_emul_work,
1060 				  button_release_emul_fn);
1061 	}
1062 
1063 	irqflags = IRQF_ONESHOT;
1064 	if (new_api)
1065 		irqflags |= IRQF_TRIGGER_LOW;
1066 	else
1067 		irqflags |= IRQF_TRIGGER_FALLING;
1068 
1069 	err = devm_request_threaded_irq(dev, mcu->client->irq, NULL,
1070 					omnia_irq_thread_handler, irqflags,
1071 					"turris-omnia-mcu", mcu);
1072 	if (err)
1073 		return dev_err_probe(dev, err, "Cannot request IRQ\n");
1074 
1075 	if (!new_api) {
1076 		/*
1077 		 * The button_release_emul_work has to be initialized before the
1078 		 * thread is requested, and on driver remove it needs to be
1079 		 * canceled before the thread is freed. Therefore we can't use
1080 		 * devm_delayed_work_autocancel() directly, because the order
1081 		 *   devm_delayed_work_autocancel();
1082 		 *   devm_request_threaded_irq();
1083 		 * would cause improper release order:
1084 		 *   free_irq();
1085 		 *   cancel_delayed_work_sync();
1086 		 * Instead we first initialize the work above, and only now
1087 		 * after IRQ is requested we add the work devm action.
1088 		 */
1089 		err = devm_add_action(dev, devm_delayed_work_drop,
1090 				      &mcu->button_release_emul_work);
1091 		if (err)
1092 			return err;
1093 	}
1094 
1095 	return 0;
1096 }
1097 
omnia_mcu_request_irq(struct omnia_mcu * mcu,u32 spec,irq_handler_t thread_fn,const char * devname)1098 int omnia_mcu_request_irq(struct omnia_mcu *mcu, u32 spec,
1099 			  irq_handler_t thread_fn, const char *devname)
1100 {
1101 	u8 irq_idx;
1102 	int irq;
1103 
1104 	if (!spec)
1105 		return -EINVAL;
1106 
1107 	irq_idx = omnia_int_to_gpio_idx[ffs(spec) - 1];
1108 	irq = gpiod_to_irq(gpio_device_get_desc(mcu->gc.gpiodev, irq_idx));
1109 	if (irq < 0)
1110 		return irq;
1111 
1112 	return devm_request_threaded_irq(&mcu->client->dev, irq, NULL,
1113 					 thread_fn, IRQF_ONESHOT, devname, mcu);
1114 }
1115