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
17static 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
44static bool stmfx_reg_writeable(struct device *dev, unsigned int reg)
45{
46	return (reg >= STMFX_REG_SYS_CTRL);
47}
48
49static 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_MAPLE,
57};
58
59static const struct resource stmfx_pinctrl_resources[] = {
60	DEFINE_RES_IRQ(STMFX_REG_IRQ_SRC_EN_GPIO),
61};
62
63static 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
68static 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
76static 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
97static 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
116int 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}
156EXPORT_SYMBOL_GPL(stmfx_function_enable);
157
158int 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}
164EXPORT_SYMBOL_GPL(stmfx_function_disable);
165
166static 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
173static 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
182static 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
189static 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
196static 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
204static 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
233static 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
244static 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
250static const struct irq_domain_ops stmfx_irq_ops = {
251	.map	= stmfx_irq_map,
252	.unmap	= stmfx_irq_unmap,
253};
254
255static 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
266static 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
303irq_exit:
304	stmfx_irq_exit(client);
305
306	return ret;
307}
308
309static 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
323static 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		stmfx->vdd = NULL;
334		if (ret != -ENODEV)
335			return dev_err_probe(&client->dev, ret, "Failed to get VDD regulator\n");
336	}
337
338	if (stmfx->vdd) {
339		ret = regulator_enable(stmfx->vdd);
340		if (ret) {
341			dev_err(&client->dev, "VDD enable failed: %d\n", ret);
342			return ret;
343		}
344	}
345
346	ret = regmap_read(stmfx->map, STMFX_REG_CHIP_ID, &id);
347	if (ret) {
348		dev_err(&client->dev, "Error reading chip ID: %d\n", ret);
349		goto err;
350	}
351
352	/*
353	 * Check that ID is the complement of the I2C address:
354	 * STMFX I2C address follows the 7-bit format (MSB), that's why
355	 * client->addr is shifted.
356	 *
357	 * STMFX_I2C_ADDR|       STMFX         |        Linux
358	 *   input pin   | I2C device address  | I2C device address
359	 *---------------------------------------------------------
360	 *       0       | b: 1000 010x h:0x84 |       0x42
361	 *       1       | b: 1000 011x h:0x86 |       0x43
362	 */
363	if (FIELD_GET(STMFX_REG_CHIP_ID_MASK, ~id) != (client->addr << 1)) {
364		dev_err(&client->dev, "Unknown chip ID: %#x\n", id);
365		ret = -EINVAL;
366		goto err;
367	}
368
369	ret = regmap_bulk_read(stmfx->map, STMFX_REG_FW_VERSION_MSB,
370			       version, ARRAY_SIZE(version));
371	if (ret) {
372		dev_err(&client->dev, "Error reading FW version: %d\n", ret);
373		goto err;
374	}
375
376	dev_info(&client->dev, "STMFX id: %#x, fw version: %x.%02x\n",
377		 id, version[0], version[1]);
378
379	ret = stmfx_chip_reset(stmfx);
380	if (ret) {
381		dev_err(&client->dev, "Failed to reset chip: %d\n", ret);
382		goto err;
383	}
384
385	return 0;
386
387err:
388	if (stmfx->vdd)
389		regulator_disable(stmfx->vdd);
390
391	return ret;
392}
393
394static void stmfx_chip_exit(struct i2c_client *client)
395{
396	struct stmfx *stmfx = i2c_get_clientdata(client);
397
398	regmap_write(stmfx->map, STMFX_REG_IRQ_SRC_EN, 0);
399	regmap_write(stmfx->map, STMFX_REG_SYS_CTRL, 0);
400
401	if (stmfx->vdd) {
402		int ret;
403
404		ret = regulator_disable(stmfx->vdd);
405		if (ret)
406			dev_err(&client->dev,
407				"Failed to disable vdd regulator: %pe\n",
408				ERR_PTR(ret));
409	}
410}
411
412static int stmfx_probe(struct i2c_client *client)
413{
414	struct device *dev = &client->dev;
415	struct stmfx *stmfx;
416	int ret;
417
418	stmfx = devm_kzalloc(dev, sizeof(*stmfx), GFP_KERNEL);
419	if (!stmfx)
420		return -ENOMEM;
421
422	i2c_set_clientdata(client, stmfx);
423
424	stmfx->dev = dev;
425
426	stmfx->map = devm_regmap_init_i2c(client, &stmfx_regmap_config);
427	if (IS_ERR(stmfx->map)) {
428		ret = PTR_ERR(stmfx->map);
429		dev_err(dev, "Failed to allocate register map: %d\n", ret);
430		return ret;
431	}
432
433	mutex_init(&stmfx->lock);
434
435	ret = stmfx_chip_init(client);
436	if (ret) {
437		if (ret == -ETIMEDOUT)
438			return -EPROBE_DEFER;
439		return ret;
440	}
441
442	if (client->irq < 0) {
443		dev_err(dev, "Failed to get IRQ: %d\n", client->irq);
444		ret = client->irq;
445		goto err_chip_exit;
446	}
447
448	ret = stmfx_irq_init(client);
449	if (ret)
450		goto err_chip_exit;
451
452	ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
453				   stmfx_cells, ARRAY_SIZE(stmfx_cells), NULL,
454				   0, stmfx->irq_domain);
455	if (ret)
456		goto err_irq_exit;
457
458	return 0;
459
460err_irq_exit:
461	stmfx_irq_exit(client);
462err_chip_exit:
463	stmfx_chip_exit(client);
464
465	return ret;
466}
467
468static void stmfx_remove(struct i2c_client *client)
469{
470	stmfx_irq_exit(client);
471
472	stmfx_chip_exit(client);
473}
474
475static int stmfx_suspend(struct device *dev)
476{
477	struct stmfx *stmfx = dev_get_drvdata(dev);
478	int ret;
479
480	ret = regmap_raw_read(stmfx->map, STMFX_REG_SYS_CTRL,
481			      &stmfx->bkp_sysctrl, sizeof(stmfx->bkp_sysctrl));
482	if (ret)
483		return ret;
484
485	ret = regmap_raw_read(stmfx->map, STMFX_REG_IRQ_OUT_PIN,
486			      &stmfx->bkp_irqoutpin,
487			      sizeof(stmfx->bkp_irqoutpin));
488	if (ret)
489		return ret;
490
491	disable_irq(stmfx->irq);
492
493	if (stmfx->vdd)
494		return regulator_disable(stmfx->vdd);
495
496	return 0;
497}
498
499static int stmfx_resume(struct device *dev)
500{
501	struct stmfx *stmfx = dev_get_drvdata(dev);
502	int ret;
503
504	if (stmfx->vdd) {
505		ret = regulator_enable(stmfx->vdd);
506		if (ret) {
507			dev_err(stmfx->dev,
508				"VDD enable failed: %d\n", ret);
509			return ret;
510		}
511	}
512
513	/* Reset STMFX - supply has been stopped during suspend */
514	ret = stmfx_chip_reset(stmfx);
515	if (ret) {
516		dev_err(stmfx->dev, "Failed to reset chip: %d\n", ret);
517		return ret;
518	}
519
520	ret = regmap_raw_write(stmfx->map, STMFX_REG_SYS_CTRL,
521			       &stmfx->bkp_sysctrl, sizeof(stmfx->bkp_sysctrl));
522	if (ret)
523		return ret;
524
525	ret = regmap_raw_write(stmfx->map, STMFX_REG_IRQ_OUT_PIN,
526			       &stmfx->bkp_irqoutpin,
527			       sizeof(stmfx->bkp_irqoutpin));
528	if (ret)
529		return ret;
530
531	ret = regmap_raw_write(stmfx->map, STMFX_REG_IRQ_SRC_EN,
532			       &stmfx->irq_src, sizeof(stmfx->irq_src));
533	if (ret)
534		return ret;
535
536	enable_irq(stmfx->irq);
537
538	return 0;
539}
540
541static DEFINE_SIMPLE_DEV_PM_OPS(stmfx_dev_pm_ops, stmfx_suspend, stmfx_resume);
542
543static const struct of_device_id stmfx_of_match[] = {
544	{ .compatible = "st,stmfx-0300", },
545	{},
546};
547MODULE_DEVICE_TABLE(of, stmfx_of_match);
548
549static struct i2c_driver stmfx_driver = {
550	.driver = {
551		.name = "stmfx-core",
552		.of_match_table = stmfx_of_match,
553		.pm = pm_sleep_ptr(&stmfx_dev_pm_ops),
554	},
555	.probe = stmfx_probe,
556	.remove = stmfx_remove,
557};
558module_i2c_driver(stmfx_driver);
559
560MODULE_DESCRIPTION("STMFX core driver");
561MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
562MODULE_LICENSE("GPL v2");
563