xref: /openbmc/linux/drivers/mfd/stmfx.c (revision 0545810f)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * Driver for STMicroelectronics Multi-Function eXpander (STMFX) core
4  *
5  * Copyright (C) 2019 STMicroelectronics
6  * Author(s): Amelie Delaunay <amelie.delaunay@st.com>.
7  */
8 #include <linux/bitfield.h>
9 #include <linux/i2c.h>
10 #include <linux/interrupt.h>
11 #include <linux/irq.h>
12 #include <linux/mfd/core.h>
13 #include <linux/mfd/stmfx.h>
14 #include <linux/module.h>
15 #include <linux/regulator/consumer.h>
16 
17 static bool stmfx_reg_volatile(struct device *dev, unsigned int reg)
18 {
19 	switch (reg) {
20 	case STMFX_REG_SYS_CTRL:
21 	case STMFX_REG_IRQ_SRC_EN:
22 	case STMFX_REG_IRQ_PENDING:
23 	case STMFX_REG_IRQ_GPI_PENDING1:
24 	case STMFX_REG_IRQ_GPI_PENDING2:
25 	case STMFX_REG_IRQ_GPI_PENDING3:
26 	case STMFX_REG_GPIO_STATE1:
27 	case STMFX_REG_GPIO_STATE2:
28 	case STMFX_REG_GPIO_STATE3:
29 	case STMFX_REG_IRQ_GPI_SRC1:
30 	case STMFX_REG_IRQ_GPI_SRC2:
31 	case STMFX_REG_IRQ_GPI_SRC3:
32 	case STMFX_REG_GPO_SET1:
33 	case STMFX_REG_GPO_SET2:
34 	case STMFX_REG_GPO_SET3:
35 	case STMFX_REG_GPO_CLR1:
36 	case STMFX_REG_GPO_CLR2:
37 	case STMFX_REG_GPO_CLR3:
38 		return true;
39 	default:
40 		return false;
41 	}
42 }
43 
44 static bool stmfx_reg_writeable(struct device *dev, unsigned int reg)
45 {
46 	return (reg >= STMFX_REG_SYS_CTRL);
47 }
48 
49 static const struct regmap_config stmfx_regmap_config = {
50 	.reg_bits	= 8,
51 	.reg_stride	= 1,
52 	.val_bits	= 8,
53 	.max_register	= STMFX_REG_MAX,
54 	.volatile_reg	= stmfx_reg_volatile,
55 	.writeable_reg	= stmfx_reg_writeable,
56 	.cache_type	= REGCACHE_RBTREE,
57 };
58 
59 static const struct resource stmfx_pinctrl_resources[] = {
60 	DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_GPIO),
61 };
62 
63 static const struct resource stmfx_idd_resources[] = {
64 	DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_IDD),
65 	DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_ERROR),
66 };
67 
68 static const struct resource stmfx_ts_resources[] = {
69 	DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_TS_DET),
70 	DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_TS_NE),
71 	DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_TS_TH),
72 	DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_TS_FULL),
73 	DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_TS_OVF),
74 };
75 
76 static struct mfd_cell stmfx_cells[] = {
77 	{
78 		.of_compatible = "st,stmfx-0300-pinctrl",
79 		.name = "stmfx-pinctrl",
80 		.resources = stmfx_pinctrl_resources,
81 		.num_resources = ARRAY_SIZE(stmfx_pinctrl_resources),
82 	},
83 	{
84 		.of_compatible = "st,stmfx-0300-idd",
85 		.name = "stmfx-idd",
86 		.resources = stmfx_idd_resources,
87 		.num_resources = ARRAY_SIZE(stmfx_idd_resources),
88 	},
89 	{
90 		.of_compatible = "st,stmfx-0300-ts",
91 		.name = "stmfx-ts",
92 		.resources = stmfx_ts_resources,
93 		.num_resources = ARRAY_SIZE(stmfx_ts_resources),
94 	},
95 };
96 
97 static u8 stmfx_func_to_mask(u32 func)
98 {
99 	u8 mask = 0;
100 
101 	if (func & STMFX_FUNC_GPIO)
102 		mask |= STMFX_REG_SYS_CTRL_GPIO_EN;
103 
104 	if ((func & STMFX_FUNC_ALTGPIO_LOW) || (func & STMFX_FUNC_ALTGPIO_HIGH))
105 		mask |= STMFX_REG_SYS_CTRL_ALTGPIO_EN;
106 
107 	if (func & STMFX_FUNC_TS)
108 		mask |= STMFX_REG_SYS_CTRL_TS_EN;
109 
110 	if (func & STMFX_FUNC_IDD)
111 		mask |= STMFX_REG_SYS_CTRL_IDD_EN;
112 
113 	return mask;
114 }
115 
116 int stmfx_function_enable(struct stmfx *stmfx, u32 func)
117 {
118 	u32 sys_ctrl;
119 	u8 mask;
120 	int ret;
121 
122 	ret = regmap_read(stmfx->map, STMFX_REG_SYS_CTRL, &sys_ctrl);
123 	if (ret)
124 		return ret;
125 
126 	/*
127 	 * IDD and TS have priority in STMFX FW, so if IDD and TS are enabled,
128 	 * ALTGPIO function is disabled by STMFX FW. If IDD or TS is enabled,
129 	 * the number of aGPIO available decreases. To avoid GPIO management
130 	 * disturbance, abort IDD or TS function enable in this case.
131 	 */
132 	if (((func & STMFX_FUNC_IDD) || (func & STMFX_FUNC_TS)) &&
133 	    (sys_ctrl & STMFX_REG_SYS_CTRL_ALTGPIO_EN)) {
134 		dev_err(stmfx->dev, "ALTGPIO function already enabled\n");
135 		return -EBUSY;
136 	}
137 
138 	/* If TS is enabled, aGPIO[3:0] cannot be used */
139 	if ((func & STMFX_FUNC_ALTGPIO_LOW) &&
140 	    (sys_ctrl & STMFX_REG_SYS_CTRL_TS_EN)) {
141 		dev_err(stmfx->dev, "TS in use, aGPIO[3:0] unavailable\n");
142 		return -EBUSY;
143 	}
144 
145 	/* If IDD is enabled, aGPIO[7:4] cannot be used */
146 	if ((func & STMFX_FUNC_ALTGPIO_HIGH) &&
147 	    (sys_ctrl & STMFX_REG_SYS_CTRL_IDD_EN)) {
148 		dev_err(stmfx->dev, "IDD in use, aGPIO[7:4] unavailable\n");
149 		return -EBUSY;
150 	}
151 
152 	mask = stmfx_func_to_mask(func);
153 
154 	return regmap_update_bits(stmfx->map, STMFX_REG_SYS_CTRL, mask, mask);
155 }
156 EXPORT_SYMBOL_GPL(stmfx_function_enable);
157 
158 int stmfx_function_disable(struct stmfx *stmfx, u32 func)
159 {
160 	u8 mask = stmfx_func_to_mask(func);
161 
162 	return regmap_update_bits(stmfx->map, STMFX_REG_SYS_CTRL, mask, 0);
163 }
164 EXPORT_SYMBOL_GPL(stmfx_function_disable);
165 
166 static void stmfx_irq_bus_lock(struct irq_data *data)
167 {
168 	struct stmfx *stmfx = irq_data_get_irq_chip_data(data);
169 
170 	mutex_lock(&stmfx->lock);
171 }
172 
173 static void stmfx_irq_bus_sync_unlock(struct irq_data *data)
174 {
175 	struct stmfx *stmfx = irq_data_get_irq_chip_data(data);
176 
177 	regmap_write(stmfx->map, STMFX_REG_IRQ_SRC_EN, stmfx->irq_src);
178 
179 	mutex_unlock(&stmfx->lock);
180 }
181 
182 static void stmfx_irq_mask(struct irq_data *data)
183 {
184 	struct stmfx *stmfx = irq_data_get_irq_chip_data(data);
185 
186 	stmfx->irq_src &= ~BIT(data->hwirq % 8);
187 }
188 
189 static void stmfx_irq_unmask(struct irq_data *data)
190 {
191 	struct stmfx *stmfx = irq_data_get_irq_chip_data(data);
192 
193 	stmfx->irq_src |= BIT(data->hwirq % 8);
194 }
195 
196 static struct irq_chip stmfx_irq_chip = {
197 	.name			= "stmfx-core",
198 	.irq_bus_lock		= stmfx_irq_bus_lock,
199 	.irq_bus_sync_unlock	= stmfx_irq_bus_sync_unlock,
200 	.irq_mask		= stmfx_irq_mask,
201 	.irq_unmask		= stmfx_irq_unmask,
202 };
203 
204 static irqreturn_t stmfx_irq_handler(int irq, void *data)
205 {
206 	struct stmfx *stmfx = data;
207 	unsigned long bits;
208 	u32 pending, ack;
209 	int n, ret;
210 
211 	ret = regmap_read(stmfx->map, STMFX_REG_IRQ_PENDING, &pending);
212 	if (ret)
213 		return IRQ_NONE;
214 
215 	/*
216 	 * There is no ACK for GPIO, MFX_REG_IRQ_PENDING_GPIO is a logical OR
217 	 * of MFX_REG_IRQ_GPI _PENDING1/_PENDING2/_PENDING3
218 	 */
219 	ack = pending & ~BIT(STMFX_REG_IRQ_SRC_EN_GPIO);
220 	if (ack) {
221 		ret = regmap_write(stmfx->map, STMFX_REG_IRQ_ACK, ack);
222 		if (ret)
223 			return IRQ_NONE;
224 	}
225 
226 	bits = pending;
227 	for_each_set_bit(n, &bits, STMFX_REG_IRQ_SRC_MAX)
228 		handle_nested_irq(irq_find_mapping(stmfx->irq_domain, n));
229 
230 	return IRQ_HANDLED;
231 }
232 
233 static int stmfx_irq_map(struct irq_domain *d, unsigned int virq,
234 			 irq_hw_number_t hwirq)
235 {
236 	irq_set_chip_data(virq, d->host_data);
237 	irq_set_chip_and_handler(virq, &stmfx_irq_chip, handle_simple_irq);
238 	irq_set_nested_thread(virq, 1);
239 	irq_set_noprobe(virq);
240 
241 	return 0;
242 }
243 
244 static void stmfx_irq_unmap(struct irq_domain *d, unsigned int virq)
245 {
246 	irq_set_chip_and_handler(virq, NULL, NULL);
247 	irq_set_chip_data(virq, NULL);
248 }
249 
250 static const struct irq_domain_ops stmfx_irq_ops = {
251 	.map	= stmfx_irq_map,
252 	.unmap	= stmfx_irq_unmap,
253 };
254 
255 static void stmfx_irq_exit(struct i2c_client *client)
256 {
257 	struct stmfx *stmfx = i2c_get_clientdata(client);
258 	int hwirq;
259 
260 	for (hwirq = 0; hwirq < STMFX_REG_IRQ_SRC_MAX; hwirq++)
261 		irq_dispose_mapping(irq_find_mapping(stmfx->irq_domain, hwirq));
262 
263 	irq_domain_remove(stmfx->irq_domain);
264 }
265 
266 static int stmfx_irq_init(struct i2c_client *client)
267 {
268 	struct stmfx *stmfx = i2c_get_clientdata(client);
269 	u32 irqoutpin = 0, irqtrigger;
270 	int ret;
271 
272 	stmfx->irq_domain = irq_domain_add_simple(stmfx->dev->of_node,
273 						  STMFX_REG_IRQ_SRC_MAX, 0,
274 						  &stmfx_irq_ops, stmfx);
275 	if (!stmfx->irq_domain) {
276 		dev_err(stmfx->dev, "Failed to create IRQ domain\n");
277 		return -EINVAL;
278 	}
279 
280 	if (!of_property_read_bool(stmfx->dev->of_node, "drive-open-drain"))
281 		irqoutpin |= STMFX_REG_IRQ_OUT_PIN_TYPE;
282 
283 	irqtrigger = irq_get_trigger_type(client->irq);
284 	if ((irqtrigger & IRQ_TYPE_EDGE_RISING) ||
285 	    (irqtrigger & IRQ_TYPE_LEVEL_HIGH))
286 		irqoutpin |= STMFX_REG_IRQ_OUT_PIN_POL;
287 
288 	ret = regmap_write(stmfx->map, STMFX_REG_IRQ_OUT_PIN, irqoutpin);
289 	if (ret)
290 		goto irq_exit;
291 
292 	ret = devm_request_threaded_irq(stmfx->dev, client->irq,
293 					NULL, stmfx_irq_handler,
294 					irqtrigger | IRQF_ONESHOT,
295 					"stmfx", stmfx);
296 	if (ret)
297 		goto irq_exit;
298 
299 	stmfx->irq = client->irq;
300 
301 	return 0;
302 
303 irq_exit:
304 	stmfx_irq_exit(client);
305 
306 	return ret;
307 }
308 
309 static int stmfx_chip_reset(struct stmfx *stmfx)
310 {
311 	int ret;
312 
313 	ret = regmap_write(stmfx->map, STMFX_REG_SYS_CTRL,
314 			   STMFX_REG_SYS_CTRL_SWRST);
315 	if (ret)
316 		return ret;
317 
318 	msleep(STMFX_BOOT_TIME_MS);
319 
320 	return ret;
321 }
322 
323 static int stmfx_chip_init(struct i2c_client *client)
324 {
325 	struct stmfx *stmfx = i2c_get_clientdata(client);
326 	u32 id;
327 	u8 version[2];
328 	int ret;
329 
330 	stmfx->vdd = devm_regulator_get_optional(&client->dev, "vdd");
331 	ret = PTR_ERR_OR_ZERO(stmfx->vdd);
332 	if (ret) {
333 		if (ret == -ENODEV)
334 			stmfx->vdd = NULL;
335 		else
336 			return dev_err_probe(&client->dev, ret, "Failed to get VDD regulator\n");
337 	}
338 
339 	if (stmfx->vdd) {
340 		ret = regulator_enable(stmfx->vdd);
341 		if (ret) {
342 			dev_err(&client->dev, "VDD enable failed: %d\n", ret);
343 			return ret;
344 		}
345 	}
346 
347 	ret = regmap_read(stmfx->map, STMFX_REG_CHIP_ID, &id);
348 	if (ret) {
349 		dev_err(&client->dev, "Error reading chip ID: %d\n", ret);
350 		goto err;
351 	}
352 
353 	/*
354 	 * Check that ID is the complement of the I2C address:
355 	 * STMFX I2C address follows the 7-bit format (MSB), that's why
356 	 * client->addr is shifted.
357 	 *
358 	 * STMFX_I2C_ADDR|       STMFX         |        Linux
359 	 *   input pin   | I2C device address  | I2C device address
360 	 *---------------------------------------------------------
361 	 *       0       | b: 1000 010x h:0x84 |       0x42
362 	 *       1       | b: 1000 011x h:0x86 |       0x43
363 	 */
364 	if (FIELD_GET(STMFX_REG_CHIP_ID_MASK, ~id) != (client->addr << 1)) {
365 		dev_err(&client->dev, "Unknown chip ID: %#x\n", id);
366 		ret = -EINVAL;
367 		goto err;
368 	}
369 
370 	ret = regmap_bulk_read(stmfx->map, STMFX_REG_FW_VERSION_MSB,
371 			       version, ARRAY_SIZE(version));
372 	if (ret) {
373 		dev_err(&client->dev, "Error reading FW version: %d\n", ret);
374 		goto err;
375 	}
376 
377 	dev_info(&client->dev, "STMFX id: %#x, fw version: %x.%02x\n",
378 		 id, version[0], version[1]);
379 
380 	ret = stmfx_chip_reset(stmfx);
381 	if (ret) {
382 		dev_err(&client->dev, "Failed to reset chip: %d\n", ret);
383 		goto err;
384 	}
385 
386 	return 0;
387 
388 err:
389 	if (stmfx->vdd)
390 		return regulator_disable(stmfx->vdd);
391 
392 	return ret;
393 }
394 
395 static void stmfx_chip_exit(struct i2c_client *client)
396 {
397 	struct stmfx *stmfx = i2c_get_clientdata(client);
398 
399 	regmap_write(stmfx->map, STMFX_REG_IRQ_SRC_EN, 0);
400 	regmap_write(stmfx->map, STMFX_REG_SYS_CTRL, 0);
401 
402 	if (stmfx->vdd) {
403 		int ret;
404 
405 		ret = regulator_disable(stmfx->vdd);
406 		if (ret)
407 			dev_err(&client->dev,
408 				"Failed to disable vdd regulator: %pe\n",
409 				ERR_PTR(ret));
410 	}
411 }
412 
413 static int stmfx_probe(struct i2c_client *client)
414 {
415 	struct device *dev = &client->dev;
416 	struct stmfx *stmfx;
417 	int ret;
418 
419 	stmfx = devm_kzalloc(dev, sizeof(*stmfx), GFP_KERNEL);
420 	if (!stmfx)
421 		return -ENOMEM;
422 
423 	i2c_set_clientdata(client, stmfx);
424 
425 	stmfx->dev = dev;
426 
427 	stmfx->map = devm_regmap_init_i2c(client, &stmfx_regmap_config);
428 	if (IS_ERR(stmfx->map)) {
429 		ret = PTR_ERR(stmfx->map);
430 		dev_err(dev, "Failed to allocate register map: %d\n", ret);
431 		return ret;
432 	}
433 
434 	mutex_init(&stmfx->lock);
435 
436 	ret = stmfx_chip_init(client);
437 	if (ret) {
438 		if (ret == -ETIMEDOUT)
439 			return -EPROBE_DEFER;
440 		return ret;
441 	}
442 
443 	if (client->irq < 0) {
444 		dev_err(dev, "Failed to get IRQ: %d\n", client->irq);
445 		ret = client->irq;
446 		goto err_chip_exit;
447 	}
448 
449 	ret = stmfx_irq_init(client);
450 	if (ret)
451 		goto err_chip_exit;
452 
453 	ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
454 				   stmfx_cells, ARRAY_SIZE(stmfx_cells), NULL,
455 				   0, stmfx->irq_domain);
456 	if (ret)
457 		goto err_irq_exit;
458 
459 	return 0;
460 
461 err_irq_exit:
462 	stmfx_irq_exit(client);
463 err_chip_exit:
464 	stmfx_chip_exit(client);
465 
466 	return ret;
467 }
468 
469 static void stmfx_remove(struct i2c_client *client)
470 {
471 	stmfx_irq_exit(client);
472 
473 	stmfx_chip_exit(client);
474 }
475 
476 static int stmfx_suspend(struct device *dev)
477 {
478 	struct stmfx *stmfx = dev_get_drvdata(dev);
479 	int ret;
480 
481 	ret = regmap_raw_read(stmfx->map, STMFX_REG_SYS_CTRL,
482 			      &stmfx->bkp_sysctrl, sizeof(stmfx->bkp_sysctrl));
483 	if (ret)
484 		return ret;
485 
486 	ret = regmap_raw_read(stmfx->map, STMFX_REG_IRQ_OUT_PIN,
487 			      &stmfx->bkp_irqoutpin,
488 			      sizeof(stmfx->bkp_irqoutpin));
489 	if (ret)
490 		return ret;
491 
492 	disable_irq(stmfx->irq);
493 
494 	if (stmfx->vdd)
495 		return regulator_disable(stmfx->vdd);
496 
497 	return 0;
498 }
499 
500 static int stmfx_resume(struct device *dev)
501 {
502 	struct stmfx *stmfx = dev_get_drvdata(dev);
503 	int ret;
504 
505 	if (stmfx->vdd) {
506 		ret = regulator_enable(stmfx->vdd);
507 		if (ret) {
508 			dev_err(stmfx->dev,
509 				"VDD enable failed: %d\n", ret);
510 			return ret;
511 		}
512 	}
513 
514 	/* Reset STMFX - supply has been stopped during suspend */
515 	ret = stmfx_chip_reset(stmfx);
516 	if (ret) {
517 		dev_err(stmfx->dev, "Failed to reset chip: %d\n", ret);
518 		return ret;
519 	}
520 
521 	ret = regmap_raw_write(stmfx->map, STMFX_REG_SYS_CTRL,
522 			       &stmfx->bkp_sysctrl, sizeof(stmfx->bkp_sysctrl));
523 	if (ret)
524 		return ret;
525 
526 	ret = regmap_raw_write(stmfx->map, STMFX_REG_IRQ_OUT_PIN,
527 			       &stmfx->bkp_irqoutpin,
528 			       sizeof(stmfx->bkp_irqoutpin));
529 	if (ret)
530 		return ret;
531 
532 	ret = regmap_raw_write(stmfx->map, STMFX_REG_IRQ_SRC_EN,
533 			       &stmfx->irq_src, sizeof(stmfx->irq_src));
534 	if (ret)
535 		return ret;
536 
537 	enable_irq(stmfx->irq);
538 
539 	return 0;
540 }
541 
542 static DEFINE_SIMPLE_DEV_PM_OPS(stmfx_dev_pm_ops, stmfx_suspend, stmfx_resume);
543 
544 static const struct of_device_id stmfx_of_match[] = {
545 	{ .compatible = "st,stmfx-0300", },
546 	{},
547 };
548 MODULE_DEVICE_TABLE(of, stmfx_of_match);
549 
550 static struct i2c_driver stmfx_driver = {
551 	.driver = {
552 		.name = "stmfx-core",
553 		.of_match_table = stmfx_of_match,
554 		.pm = pm_sleep_ptr(&stmfx_dev_pm_ops),
555 	},
556 	.probe_new = stmfx_probe,
557 	.remove = stmfx_remove,
558 };
559 module_i2c_driver(stmfx_driver);
560 
561 MODULE_DESCRIPTION("STMFX core driver");
562 MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
563 MODULE_LICENSE("GPL v2");
564