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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 <[email protected]>.
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_create_simple(dev_fwnode(stmfx->dev), STMFX_REG_IRQ_SRC_MAX,
273 0, &stmfx_irq_ops, stmfx);
274 if (!stmfx->irq_domain) {
275 dev_err(stmfx->dev, "Failed to create IRQ domain\n");
276 return -EINVAL;
277 }
278
279 if (!of_property_read_bool(stmfx->dev->of_node, "drive-open-drain"))
280 irqoutpin |= STMFX_REG_IRQ_OUT_PIN_TYPE;
281
282 irqtrigger = irq_get_trigger_type(client->irq);
283 if ((irqtrigger & IRQ_TYPE_EDGE_RISING) ||
284 (irqtrigger & IRQ_TYPE_LEVEL_HIGH))
285 irqoutpin |= STMFX_REG_IRQ_OUT_PIN_POL;
286
287 ret = regmap_write(stmfx->map, STMFX_REG_IRQ_OUT_PIN, irqoutpin);
288 if (ret)
289 goto irq_exit;
290
291 ret = devm_request_threaded_irq(stmfx->dev, client->irq,
292 NULL, stmfx_irq_handler,
293 irqtrigger | IRQF_ONESHOT,
294 "stmfx", stmfx);
295 if (ret)
296 goto irq_exit;
297
298 stmfx->irq = client->irq;
299
300 return 0;
301
302irq_exit:
303 stmfx_irq_exit(client);
304
305 return ret;
306}
307
308static int stmfx_chip_reset(struct stmfx *stmfx)
309{
310 int ret;
311
312 ret = regmap_write(stmfx->map, STMFX_REG_SYS_CTRL,
313 STMFX_REG_SYS_CTRL_SWRST);
314 if (ret)
315 return ret;
316
317 msleep(STMFX_BOOT_TIME_MS);
318
319 return ret;
320}
321
322static int stmfx_chip_init(struct i2c_client *client)
323{
324 struct stmfx *stmfx = i2c_get_clientdata(client);
325 u32 id;
326 u8 version[2];
327 int ret;
328
329 stmfx->vdd = devm_regulator_get_optional(&client->dev, "vdd");
330 ret = PTR_ERR_OR_ZERO(stmfx->vdd);
331 if (ret) {
332 stmfx->vdd = NULL;
333 if (ret != -ENODEV)
334 return dev_err_probe(&client->dev, ret, "Failed to get VDD regulator\n");
335 }
336
337 if (stmfx->vdd) {
338 ret = regulator_enable(stmfx->vdd);
339 if (ret) {
340 dev_err(&client->dev, "VDD enable failed: %d\n", ret);
341 return ret;
342 }
343 }
344
345 ret = regmap_read(stmfx->map, STMFX_REG_CHIP_ID, &id);
346 if (ret) {
347 dev_err(&client->dev, "Error reading chip ID: %d\n", ret);
348 goto err;
349 }
350
351 /*
352 * Check that ID is the complement of the I2C address:
353 * STMFX I2C address follows the 7-bit format (MSB), that's why
354 * client->addr is shifted.
355 *
356 * STMFX_I2C_ADDR| STMFX | Linux
357 * input pin | I2C device address | I2C device address
358 *---------------------------------------------------------
359 * 0 | b: 1000 010x h:0x84 | 0x42
360 * 1 | b: 1000 011x h:0x86 | 0x43
361 */
362 if (FIELD_GET(STMFX_REG_CHIP_ID_MASK, ~id) != (client->addr << 1)) {
363 dev_err(&client->dev, "Unknown chip ID: %#x\n", id);
364 ret = -EINVAL;
365 goto err;
366 }
367
368 ret = regmap_bulk_read(stmfx->map, STMFX_REG_FW_VERSION_MSB,
369 version, ARRAY_SIZE(version));
370 if (ret) {
371 dev_err(&client->dev, "Error reading FW version: %d\n", ret);
372 goto err;
373 }
374
375 dev_info(&client->dev, "STMFX id: %#x, fw version: %x.%02x\n",
376 id, version[0], version[1]);
377
378 ret = stmfx_chip_reset(stmfx);
379 if (ret) {
380 dev_err(&client->dev, "Failed to reset chip: %d\n", ret);
381 goto err;
382 }
383
384 return 0;
385
386err:
387 if (stmfx->vdd)
388 regulator_disable(stmfx->vdd);
389
390 return ret;
391}
392
393static void stmfx_chip_exit(struct i2c_client *client)
394{
395 struct stmfx *stmfx = i2c_get_clientdata(client);
396
397 regmap_write(stmfx->map, STMFX_REG_IRQ_SRC_EN, 0);
398 regmap_write(stmfx->map, STMFX_REG_SYS_CTRL, 0);
399
400 if (stmfx->vdd) {
401 int ret;
402
403 ret = regulator_disable(stmfx->vdd);
404 if (ret)
405 dev_err(&client->dev,
406 "Failed to disable vdd regulator: %pe\n",
407 ERR_PTR(ret));
408 }
409}
410
411static int stmfx_probe(struct i2c_client *client)
412{
413 struct device *dev = &client->dev;
414 struct stmfx *stmfx;
415 int ret;
416
417 stmfx = devm_kzalloc(dev, sizeof(*stmfx), GFP_KERNEL);
418 if (!stmfx)
419 return -ENOMEM;
420
421 i2c_set_clientdata(client, stmfx);
422
423 stmfx->dev = dev;
424
425 stmfx->map = devm_regmap_init_i2c(client, &stmfx_regmap_config);
426 if (IS_ERR(stmfx->map)) {
427 ret = PTR_ERR(stmfx->map);
428 dev_err(dev, "Failed to allocate register map: %d\n", ret);
429 return ret;
430 }
431
432 mutex_init(&stmfx->lock);
433
434 ret = stmfx_chip_init(client);
435 if (ret) {
436 if (ret == -ETIMEDOUT)
437 return -EPROBE_DEFER;
438 return ret;
439 }
440
441 if (client->irq < 0) {
442 dev_err(dev, "Failed to get IRQ: %d\n", client->irq);
443 ret = client->irq;
444 goto err_chip_exit;
445 }
446
447 ret = stmfx_irq_init(client);
448 if (ret)
449 goto err_chip_exit;
450
451 ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
452 stmfx_cells, ARRAY_SIZE(stmfx_cells), NULL,
453 0, stmfx->irq_domain);
454 if (ret)
455 goto err_irq_exit;
456
457 return 0;
458
459err_irq_exit:
460 stmfx_irq_exit(client);
461err_chip_exit:
462 stmfx_chip_exit(client);
463
464 return ret;
465}
466
467static void stmfx_remove(struct i2c_client *client)
468{
469 stmfx_irq_exit(client);
470
471 stmfx_chip_exit(client);
472}
473
474static int stmfx_suspend(struct device *dev)
475{
476 struct stmfx *stmfx = dev_get_drvdata(dev);
477 int ret;
478
479 ret = regmap_raw_read(stmfx->map, STMFX_REG_SYS_CTRL,
480 &stmfx->bkp_sysctrl, sizeof(stmfx->bkp_sysctrl));
481 if (ret)
482 return ret;
483
484 ret = regmap_raw_read(stmfx->map, STMFX_REG_IRQ_OUT_PIN,
485 &stmfx->bkp_irqoutpin,
486 sizeof(stmfx->bkp_irqoutpin));
487 if (ret)
488 return ret;
489
490 disable_irq(stmfx->irq);
491
492 if (stmfx->vdd)
493 return regulator_disable(stmfx->vdd);
494
495 return 0;
496}
497
498static int stmfx_resume(struct device *dev)
499{
500 struct stmfx *stmfx = dev_get_drvdata(dev);
501 int ret;
502
503 if (stmfx->vdd) {
504 ret = regulator_enable(stmfx->vdd);
505 if (ret) {
506 dev_err(stmfx->dev,
507 "VDD enable failed: %d\n", ret);
508 return ret;
509 }
510 }
511
512 /* Reset STMFX - supply has been stopped during suspend */
513 ret = stmfx_chip_reset(stmfx);
514 if (ret) {
515 dev_err(stmfx->dev, "Failed to reset chip: %d\n", ret);
516 return ret;
517 }
518
519 ret = regmap_raw_write(stmfx->map, STMFX_REG_SYS_CTRL,
520 &stmfx->bkp_sysctrl, sizeof(stmfx->bkp_sysctrl));
521 if (ret)
522 return ret;
523
524 ret = regmap_raw_write(stmfx->map, STMFX_REG_IRQ_OUT_PIN,
525 &stmfx->bkp_irqoutpin,
526 sizeof(stmfx->bkp_irqoutpin));
527 if (ret)
528 return ret;
529
530 ret = regmap_raw_write(stmfx->map, STMFX_REG_IRQ_SRC_EN,
531 &stmfx->irq_src, sizeof(stmfx->irq_src));
532 if (ret)
533 return ret;
534
535 enable_irq(stmfx->irq);
536
537 return 0;
538}
539
540static DEFINE_SIMPLE_DEV_PM_OPS(stmfx_dev_pm_ops, stmfx_suspend, stmfx_resume);
541
542static const struct of_device_id stmfx_of_match[] = {
543 { .compatible = "st,stmfx-0300", },
544 {},
545};
546MODULE_DEVICE_TABLE(of, stmfx_of_match);
547
548static struct i2c_driver stmfx_driver = {
549 .driver = {
550 .name = "stmfx-core",
551 .of_match_table = stmfx_of_match,
552 .pm = pm_sleep_ptr(&stmfx_dev_pm_ops),
553 },
554 .probe = stmfx_probe,
555 .remove = stmfx_remove,
556};
557module_i2c_driver(stmfx_driver);
558
559MODULE_DESCRIPTION("STMFX core driver");
560MODULE_AUTHOR("Amelie Delaunay <[email protected]>");
561MODULE_LICENSE("GPL v2");