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
stmfx_reg_volatile(struct device * dev,unsigned int reg)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
stmfx_reg_writeable(struct device * dev,unsigned int reg)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
stmfx_func_to_mask(u32 func)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
stmfx_function_enable(struct stmfx * stmfx,u32 func)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
stmfx_function_disable(struct stmfx * stmfx,u32 func)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
stmfx_irq_bus_lock(struct irq_data * data)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
stmfx_irq_bus_sync_unlock(struct irq_data * data)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
stmfx_irq_mask(struct irq_data * data)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
stmfx_irq_unmask(struct irq_data * data)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
stmfx_irq_handler(int irq,void * data)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
stmfx_irq_map(struct irq_domain * d,unsigned int virq,irq_hw_number_t hwirq)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
stmfx_irq_unmap(struct irq_domain * d,unsigned int virq)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
stmfx_irq_exit(struct i2c_client * client)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
stmfx_irq_init(struct i2c_client * client)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
stmfx_chip_reset(struct stmfx * stmfx)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
stmfx_chip_init(struct i2c_client * client)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 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
387 err:
388 if (stmfx->vdd)
389 regulator_disable(stmfx->vdd);
390
391 return ret;
392 }
393
stmfx_chip_exit(struct i2c_client * client)394 static 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
stmfx_probe(struct i2c_client * client)412 static 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
460 err_irq_exit:
461 stmfx_irq_exit(client);
462 err_chip_exit:
463 stmfx_chip_exit(client);
464
465 return ret;
466 }
467
stmfx_remove(struct i2c_client * client)468 static void stmfx_remove(struct i2c_client *client)
469 {
470 stmfx_irq_exit(client);
471
472 stmfx_chip_exit(client);
473 }
474
stmfx_suspend(struct device * dev)475 static 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
stmfx_resume(struct device * dev)499 static 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
541 static DEFINE_SIMPLE_DEV_PM_OPS(stmfx_dev_pm_ops, stmfx_suspend, stmfx_resume);
542
543 static const struct of_device_id stmfx_of_match[] = {
544 { .compatible = "st,stmfx-0300", },
545 {},
546 };
547 MODULE_DEVICE_TABLE(of, stmfx_of_match);
548
549 static 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 };
558 module_i2c_driver(stmfx_driver);
559
560 MODULE_DESCRIPTION("STMFX core driver");
561 MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
562 MODULE_LICENSE("GPL v2");
563