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 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
stmfx_chip_exit(struct i2c_client * client)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
stmfx_probe(struct i2c_client * client,const struct i2c_device_id * id)413 static int stmfx_probe(struct i2c_client *client,
414 const struct i2c_device_id *id)
415 {
416 struct device *dev = &client->dev;
417 struct stmfx *stmfx;
418 int ret;
419
420 stmfx = devm_kzalloc(dev, sizeof(*stmfx), GFP_KERNEL);
421 if (!stmfx)
422 return -ENOMEM;
423
424 i2c_set_clientdata(client, stmfx);
425
426 stmfx->dev = dev;
427
428 stmfx->map = devm_regmap_init_i2c(client, &stmfx_regmap_config);
429 if (IS_ERR(stmfx->map)) {
430 ret = PTR_ERR(stmfx->map);
431 dev_err(dev, "Failed to allocate register map: %d\n", ret);
432 return ret;
433 }
434
435 mutex_init(&stmfx->lock);
436
437 ret = stmfx_chip_init(client);
438 if (ret) {
439 if (ret == -ETIMEDOUT)
440 return -EPROBE_DEFER;
441 return ret;
442 }
443
444 if (client->irq < 0) {
445 dev_err(dev, "Failed to get IRQ: %d\n", client->irq);
446 ret = client->irq;
447 goto err_chip_exit;
448 }
449
450 ret = stmfx_irq_init(client);
451 if (ret)
452 goto err_chip_exit;
453
454 ret = devm_mfd_add_devices(dev, PLATFORM_DEVID_NONE,
455 stmfx_cells, ARRAY_SIZE(stmfx_cells), NULL,
456 0, stmfx->irq_domain);
457 if (ret)
458 goto err_irq_exit;
459
460 return 0;
461
462 err_irq_exit:
463 stmfx_irq_exit(client);
464 err_chip_exit:
465 stmfx_chip_exit(client);
466
467 return ret;
468 }
469
stmfx_remove(struct i2c_client * client)470 static void stmfx_remove(struct i2c_client *client)
471 {
472 stmfx_irq_exit(client);
473
474 stmfx_chip_exit(client);
475 }
476
477 #ifdef CONFIG_PM_SLEEP
stmfx_suspend(struct device * dev)478 static int stmfx_suspend(struct device *dev)
479 {
480 struct stmfx *stmfx = dev_get_drvdata(dev);
481 int ret;
482
483 ret = regmap_raw_read(stmfx->map, STMFX_REG_SYS_CTRL,
484 &stmfx->bkp_sysctrl, sizeof(stmfx->bkp_sysctrl));
485 if (ret)
486 return ret;
487
488 ret = regmap_raw_read(stmfx->map, STMFX_REG_IRQ_OUT_PIN,
489 &stmfx->bkp_irqoutpin,
490 sizeof(stmfx->bkp_irqoutpin));
491 if (ret)
492 return ret;
493
494 disable_irq(stmfx->irq);
495
496 if (stmfx->vdd)
497 return regulator_disable(stmfx->vdd);
498
499 return 0;
500 }
501
stmfx_resume(struct device * dev)502 static int stmfx_resume(struct device *dev)
503 {
504 struct stmfx *stmfx = dev_get_drvdata(dev);
505 int ret;
506
507 if (stmfx->vdd) {
508 ret = regulator_enable(stmfx->vdd);
509 if (ret) {
510 dev_err(stmfx->dev,
511 "VDD enable failed: %d\n", ret);
512 return ret;
513 }
514 }
515
516 /* Reset STMFX - supply has been stopped during suspend */
517 ret = stmfx_chip_reset(stmfx);
518 if (ret) {
519 dev_err(stmfx->dev, "Failed to reset chip: %d\n", ret);
520 return ret;
521 }
522
523 ret = regmap_raw_write(stmfx->map, STMFX_REG_SYS_CTRL,
524 &stmfx->bkp_sysctrl, sizeof(stmfx->bkp_sysctrl));
525 if (ret)
526 return ret;
527
528 ret = regmap_raw_write(stmfx->map, STMFX_REG_IRQ_OUT_PIN,
529 &stmfx->bkp_irqoutpin,
530 sizeof(stmfx->bkp_irqoutpin));
531 if (ret)
532 return ret;
533
534 ret = regmap_raw_write(stmfx->map, STMFX_REG_IRQ_SRC_EN,
535 &stmfx->irq_src, sizeof(stmfx->irq_src));
536 if (ret)
537 return ret;
538
539 enable_irq(stmfx->irq);
540
541 return 0;
542 }
543 #endif
544
545 static SIMPLE_DEV_PM_OPS(stmfx_dev_pm_ops, stmfx_suspend, stmfx_resume);
546
547 static const struct of_device_id stmfx_of_match[] = {
548 { .compatible = "st,stmfx-0300", },
549 {},
550 };
551 MODULE_DEVICE_TABLE(of, stmfx_of_match);
552
553 static struct i2c_driver stmfx_driver = {
554 .driver = {
555 .name = "stmfx-core",
556 .of_match_table = stmfx_of_match,
557 .pm = &stmfx_dev_pm_ops,
558 },
559 .probe = stmfx_probe,
560 .remove = stmfx_remove,
561 };
562 module_i2c_driver(stmfx_driver);
563
564 MODULE_DESCRIPTION("STMFX core driver");
565 MODULE_AUTHOR("Amelie Delaunay <amelie.delaunay@st.com>");
566 MODULE_LICENSE("GPL v2");
567