xref: /openbmc/linux/drivers/i2c/busses/i2c-cht-wc.c (revision 7a2f6f61)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Intel CHT Whiskey Cove PMIC I2C Master driver
4  * Copyright (C) 2017 Hans de Goede <hdegoede@redhat.com>
5  *
6  * Based on various non upstream patches to support the CHT Whiskey Cove PMIC:
7  * Copyright (C) 2011 - 2014 Intel Corporation. All rights reserved.
8  */
9 
10 #include <linux/acpi.h>
11 #include <linux/completion.h>
12 #include <linux/delay.h>
13 #include <linux/i2c.h>
14 #include <linux/interrupt.h>
15 #include <linux/irq.h>
16 #include <linux/irqdomain.h>
17 #include <linux/mfd/intel_soc_pmic.h>
18 #include <linux/module.h>
19 #include <linux/platform_device.h>
20 #include <linux/power/bq24190_charger.h>
21 #include <linux/power/bq25890_charger.h>
22 #include <linux/slab.h>
23 
24 #define CHT_WC_I2C_CTRL			0x5e24
25 #define CHT_WC_I2C_CTRL_WR		BIT(0)
26 #define CHT_WC_I2C_CTRL_RD		BIT(1)
27 #define CHT_WC_I2C_CLIENT_ADDR		0x5e25
28 #define CHT_WC_I2C_REG_OFFSET		0x5e26
29 #define CHT_WC_I2C_WRDATA		0x5e27
30 #define CHT_WC_I2C_RDDATA		0x5e28
31 
32 #define CHT_WC_EXTCHGRIRQ		0x6e0a
33 #define CHT_WC_EXTCHGRIRQ_CLIENT_IRQ	BIT(0)
34 #define CHT_WC_EXTCHGRIRQ_WRITE_IRQ	BIT(1)
35 #define CHT_WC_EXTCHGRIRQ_READ_IRQ	BIT(2)
36 #define CHT_WC_EXTCHGRIRQ_NACK_IRQ	BIT(3)
37 #define CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK	((u8)GENMASK(3, 1))
38 #define CHT_WC_EXTCHGRIRQ_MSK		0x6e17
39 
40 struct cht_wc_i2c_adap {
41 	struct i2c_adapter adapter;
42 	wait_queue_head_t wait;
43 	struct irq_chip irqchip;
44 	struct mutex adap_lock;
45 	struct mutex irqchip_lock;
46 	struct regmap *regmap;
47 	struct irq_domain *irq_domain;
48 	struct i2c_client *client;
49 	int client_irq;
50 	u8 irq_mask;
51 	u8 old_irq_mask;
52 	int read_data;
53 	bool io_error;
54 	bool done;
55 };
56 
57 static irqreturn_t cht_wc_i2c_adap_thread_handler(int id, void *data)
58 {
59 	struct cht_wc_i2c_adap *adap = data;
60 	int ret, reg;
61 
62 	mutex_lock(&adap->adap_lock);
63 
64 	/* Read IRQs */
65 	ret = regmap_read(adap->regmap, CHT_WC_EXTCHGRIRQ, &reg);
66 	if (ret) {
67 		dev_err(&adap->adapter.dev, "Error reading extchgrirq reg\n");
68 		mutex_unlock(&adap->adap_lock);
69 		return IRQ_NONE;
70 	}
71 
72 	reg &= ~adap->irq_mask;
73 
74 	/* Reads must be acked after reading the received data. */
75 	ret = regmap_read(adap->regmap, CHT_WC_I2C_RDDATA, &adap->read_data);
76 	if (ret)
77 		adap->io_error = true;
78 
79 	/*
80 	 * Immediately ack IRQs, so that if new IRQs arrives while we're
81 	 * handling the previous ones our irq will re-trigger when we're done.
82 	 */
83 	ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ, reg);
84 	if (ret)
85 		dev_err(&adap->adapter.dev, "Error writing extchgrirq reg\n");
86 
87 	if (reg & CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK) {
88 		adap->io_error |= !!(reg & CHT_WC_EXTCHGRIRQ_NACK_IRQ);
89 		adap->done = true;
90 	}
91 
92 	mutex_unlock(&adap->adap_lock);
93 
94 	if (reg & CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK)
95 		wake_up(&adap->wait);
96 
97 	/*
98 	 * Do NOT use handle_nested_irq here, the client irq handler will
99 	 * likely want to do i2c transfers and the i2c controller uses this
100 	 * interrupt handler as well, so running the client irq handler from
101 	 * this thread will cause things to lock up.
102 	 */
103 	if (reg & CHT_WC_EXTCHGRIRQ_CLIENT_IRQ)
104 		generic_handle_irq_safe(adap->client_irq);
105 
106 	return IRQ_HANDLED;
107 }
108 
109 static u32 cht_wc_i2c_adap_master_func(struct i2c_adapter *adap)
110 {
111 	/* This i2c adapter only supports SMBUS byte transfers */
112 	return I2C_FUNC_SMBUS_BYTE_DATA;
113 }
114 
115 static int cht_wc_i2c_adap_smbus_xfer(struct i2c_adapter *_adap, u16 addr,
116 				      unsigned short flags, char read_write,
117 				      u8 command, int size,
118 				      union i2c_smbus_data *data)
119 {
120 	struct cht_wc_i2c_adap *adap = i2c_get_adapdata(_adap);
121 	int ret;
122 
123 	mutex_lock(&adap->adap_lock);
124 	adap->io_error = false;
125 	adap->done = false;
126 	mutex_unlock(&adap->adap_lock);
127 
128 	ret = regmap_write(adap->regmap, CHT_WC_I2C_CLIENT_ADDR, addr);
129 	if (ret)
130 		return ret;
131 
132 	if (read_write == I2C_SMBUS_WRITE) {
133 		ret = regmap_write(adap->regmap, CHT_WC_I2C_WRDATA, data->byte);
134 		if (ret)
135 			return ret;
136 	}
137 
138 	ret = regmap_write(adap->regmap, CHT_WC_I2C_REG_OFFSET, command);
139 	if (ret)
140 		return ret;
141 
142 	ret = regmap_write(adap->regmap, CHT_WC_I2C_CTRL,
143 			   (read_write == I2C_SMBUS_WRITE) ?
144 			   CHT_WC_I2C_CTRL_WR : CHT_WC_I2C_CTRL_RD);
145 	if (ret)
146 		return ret;
147 
148 	ret = wait_event_timeout(adap->wait, adap->done, msecs_to_jiffies(30));
149 	if (ret == 0) {
150 		/*
151 		 * The CHT GPIO controller serializes all IRQs, sometimes
152 		 * causing significant delays, check status manually.
153 		 */
154 		cht_wc_i2c_adap_thread_handler(0, adap);
155 		if (!adap->done)
156 			return -ETIMEDOUT;
157 	}
158 
159 	ret = 0;
160 	mutex_lock(&adap->adap_lock);
161 	if (adap->io_error)
162 		ret = -EIO;
163 	else if (read_write == I2C_SMBUS_READ)
164 		data->byte = adap->read_data;
165 	mutex_unlock(&adap->adap_lock);
166 
167 	return ret;
168 }
169 
170 static const struct i2c_algorithm cht_wc_i2c_adap_algo = {
171 	.functionality = cht_wc_i2c_adap_master_func,
172 	.smbus_xfer = cht_wc_i2c_adap_smbus_xfer,
173 };
174 
175 /*
176  * We are an i2c-adapter which itself is part of an i2c-client. This means that
177  * transfers done through us take adapter->bus_lock twice, once for our parent
178  * i2c-adapter and once to take our own bus_lock. Lockdep does not like this
179  * nested locking, to make lockdep happy in the case of busses with muxes, the
180  * i2c-core's i2c_adapter_lock_bus function calls:
181  * rt_mutex_lock_nested(&adapter->bus_lock, i2c_adapter_depth(adapter));
182  *
183  * But i2c_adapter_depth only works when the direct parent of the adapter is
184  * another adapter, as it is only meant for muxes. In our case there is an
185  * i2c-client and MFD instantiated platform_device in the parent->child chain
186  * between the 2 devices.
187  *
188  * So we override the default i2c_lock_operations and pass a hardcoded
189  * depth of 1 to rt_mutex_lock_nested, to make lockdep happy.
190  *
191  * Note that if there were to be a mux attached to our adapter, this would
192  * break things again since the i2c-mux code expects the root-adapter to have
193  * a locking depth of 0. But we always have only 1 client directly attached
194  * in the form of the Charger IC paired with the CHT Whiskey Cove PMIC.
195  */
196 static void cht_wc_i2c_adap_lock_bus(struct i2c_adapter *adapter,
197 				 unsigned int flags)
198 {
199 	rt_mutex_lock_nested(&adapter->bus_lock, 1);
200 }
201 
202 static int cht_wc_i2c_adap_trylock_bus(struct i2c_adapter *adapter,
203 				   unsigned int flags)
204 {
205 	return rt_mutex_trylock(&adapter->bus_lock);
206 }
207 
208 static void cht_wc_i2c_adap_unlock_bus(struct i2c_adapter *adapter,
209 				   unsigned int flags)
210 {
211 	rt_mutex_unlock(&adapter->bus_lock);
212 }
213 
214 static const struct i2c_lock_operations cht_wc_i2c_adap_lock_ops = {
215 	.lock_bus =    cht_wc_i2c_adap_lock_bus,
216 	.trylock_bus = cht_wc_i2c_adap_trylock_bus,
217 	.unlock_bus =  cht_wc_i2c_adap_unlock_bus,
218 };
219 
220 /**** irqchip for the client connected to the extchgr i2c adapter ****/
221 static void cht_wc_i2c_irq_lock(struct irq_data *data)
222 {
223 	struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data);
224 
225 	mutex_lock(&adap->irqchip_lock);
226 }
227 
228 static void cht_wc_i2c_irq_sync_unlock(struct irq_data *data)
229 {
230 	struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data);
231 	int ret;
232 
233 	if (adap->irq_mask != adap->old_irq_mask) {
234 		ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ_MSK,
235 				   adap->irq_mask);
236 		if (ret == 0)
237 			adap->old_irq_mask = adap->irq_mask;
238 		else
239 			dev_err(&adap->adapter.dev, "Error writing EXTCHGRIRQ_MSK\n");
240 	}
241 
242 	mutex_unlock(&adap->irqchip_lock);
243 }
244 
245 static void cht_wc_i2c_irq_enable(struct irq_data *data)
246 {
247 	struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data);
248 
249 	adap->irq_mask &= ~CHT_WC_EXTCHGRIRQ_CLIENT_IRQ;
250 }
251 
252 static void cht_wc_i2c_irq_disable(struct irq_data *data)
253 {
254 	struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data);
255 
256 	adap->irq_mask |= CHT_WC_EXTCHGRIRQ_CLIENT_IRQ;
257 }
258 
259 static const struct irq_chip cht_wc_i2c_irq_chip = {
260 	.irq_bus_lock		= cht_wc_i2c_irq_lock,
261 	.irq_bus_sync_unlock	= cht_wc_i2c_irq_sync_unlock,
262 	.irq_disable		= cht_wc_i2c_irq_disable,
263 	.irq_enable		= cht_wc_i2c_irq_enable,
264 	.name			= "cht_wc_ext_chrg_irq_chip",
265 };
266 
267 /********** GPD Win / Pocket charger IC settings **********/
268 static const char * const bq24190_suppliers[] = {
269 	"tcpm-source-psy-i2c-fusb302" };
270 
271 static const struct property_entry bq24190_props[] = {
272 	PROPERTY_ENTRY_STRING_ARRAY("supplied-from", bq24190_suppliers),
273 	PROPERTY_ENTRY_BOOL("omit-battery-class"),
274 	PROPERTY_ENTRY_BOOL("disable-reset"),
275 	{ }
276 };
277 
278 static const struct software_node bq24190_node = {
279 	.properties = bq24190_props,
280 };
281 
282 static struct regulator_consumer_supply fusb302_consumer = {
283 	.supply = "vbus",
284 	/* Must match fusb302 dev_name in intel_cht_int33fe.c */
285 	.dev_name = "i2c-fusb302",
286 };
287 
288 static const struct regulator_init_data bq24190_vbus_init_data = {
289 	.constraints = {
290 		/* The name is used in intel_cht_int33fe.c do not change. */
291 		.name = "cht_wc_usb_typec_vbus",
292 		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
293 	},
294 	.consumer_supplies = &fusb302_consumer,
295 	.num_consumer_supplies = 1,
296 };
297 
298 static struct bq24190_platform_data bq24190_pdata = {
299 	.regulator_init_data = &bq24190_vbus_init_data,
300 };
301 
302 static struct i2c_board_info gpd_win_board_info = {
303 	.type = "bq24190",
304 	.addr = 0x6b,
305 	.dev_name = "bq24190",
306 	.swnode = &bq24190_node,
307 	.platform_data = &bq24190_pdata,
308 };
309 
310 /********** Xiaomi Mi Pad 2 charger IC settings  **********/
311 static struct regulator_consumer_supply bq2589x_vbus_consumer = {
312 	.supply = "vbus",
313 	.dev_name = "cht_wcove_pwrsrc",
314 };
315 
316 static const struct regulator_init_data bq2589x_vbus_init_data = {
317 	.constraints = {
318 		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
319 	},
320 	.consumer_supplies = &bq2589x_vbus_consumer,
321 	.num_consumer_supplies = 1,
322 };
323 
324 static struct bq25890_platform_data bq2589x_pdata = {
325 	.regulator_init_data = &bq2589x_vbus_init_data,
326 };
327 
328 static const struct property_entry xiaomi_mipad2_props[] = {
329 	PROPERTY_ENTRY_BOOL("linux,skip-reset"),
330 	PROPERTY_ENTRY_BOOL("linux,read-back-settings"),
331 	{ }
332 };
333 
334 static const struct software_node xiaomi_mipad2_node = {
335 	.properties = xiaomi_mipad2_props,
336 };
337 
338 static struct i2c_board_info xiaomi_mipad2_board_info = {
339 	.type = "bq25890",
340 	.addr = 0x6a,
341 	.dev_name = "bq25890",
342 	.swnode = &xiaomi_mipad2_node,
343 	.platform_data = &bq2589x_pdata,
344 };
345 
346 /********** Lenovo Yogabook YB1-X90F/-X91F/-X91L charger settings **********/
347 static const char * const lenovo_yb1_bq25892_suppliers[] = { "cht_wcove_pwrsrc" };
348 
349 static const struct property_entry lenovo_yb1_bq25892_props[] = {
350 	PROPERTY_ENTRY_STRING_ARRAY("supplied-from",
351 				    lenovo_yb1_bq25892_suppliers),
352 	PROPERTY_ENTRY_U32("linux,pump-express-vbus-max", 12000000),
353 	PROPERTY_ENTRY_BOOL("linux,skip-reset"),
354 	/*
355 	 * The firmware sets everything to the defaults, which leads to a
356 	 * somewhat low charge-current of 2048mA and worse to a battery-voltage
357 	 * of 4.2V instead of 4.35V (when booted without a charger connected).
358 	 * Use our own values instead of "linux,read-back-settings" to fix this.
359 	 */
360 	PROPERTY_ENTRY_U32("ti,charge-current", 4224000),
361 	PROPERTY_ENTRY_U32("ti,battery-regulation-voltage", 4352000),
362 	PROPERTY_ENTRY_U32("ti,termination-current", 256000),
363 	PROPERTY_ENTRY_U32("ti,precharge-current", 128000),
364 	PROPERTY_ENTRY_U32("ti,minimum-sys-voltage", 3500000),
365 	PROPERTY_ENTRY_U32("ti,boost-voltage", 4998000),
366 	PROPERTY_ENTRY_U32("ti,boost-max-current", 1400000),
367 	PROPERTY_ENTRY_BOOL("ti,use-ilim-pin"),
368 	{ }
369 };
370 
371 static const struct software_node lenovo_yb1_bq25892_node = {
372 	.properties = lenovo_yb1_bq25892_props,
373 };
374 
375 static struct i2c_board_info lenovo_yogabook1_board_info = {
376 	.type = "bq25892",
377 	.addr = 0x6b,
378 	.dev_name = "bq25892",
379 	.swnode = &lenovo_yb1_bq25892_node,
380 	.platform_data = &bq2589x_pdata,
381 };
382 
383 static int cht_wc_i2c_adap_i2c_probe(struct platform_device *pdev)
384 {
385 	struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
386 	struct i2c_board_info *board_info = NULL;
387 	struct cht_wc_i2c_adap *adap;
388 	int ret, reg, irq;
389 
390 	irq = platform_get_irq(pdev, 0);
391 	if (irq < 0)
392 		return irq;
393 
394 	adap = devm_kzalloc(&pdev->dev, sizeof(*adap), GFP_KERNEL);
395 	if (!adap)
396 		return -ENOMEM;
397 
398 	init_waitqueue_head(&adap->wait);
399 	mutex_init(&adap->adap_lock);
400 	mutex_init(&adap->irqchip_lock);
401 	adap->irqchip = cht_wc_i2c_irq_chip;
402 	adap->regmap = pmic->regmap;
403 	adap->adapter.owner = THIS_MODULE;
404 	adap->adapter.class = I2C_CLASS_HWMON;
405 	adap->adapter.algo = &cht_wc_i2c_adap_algo;
406 	adap->adapter.lock_ops = &cht_wc_i2c_adap_lock_ops;
407 	strlcpy(adap->adapter.name, "PMIC I2C Adapter",
408 		sizeof(adap->adapter.name));
409 	adap->adapter.dev.parent = &pdev->dev;
410 
411 	/* Clear and activate i2c-adapter interrupts, disable client IRQ */
412 	adap->old_irq_mask = adap->irq_mask = ~CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK;
413 
414 	ret = regmap_read(adap->regmap, CHT_WC_I2C_RDDATA, &reg);
415 	if (ret)
416 		return ret;
417 
418 	ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ, ~adap->irq_mask);
419 	if (ret)
420 		return ret;
421 
422 	ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ_MSK, adap->irq_mask);
423 	if (ret)
424 		return ret;
425 
426 	/* Alloc and register client IRQ */
427 	adap->irq_domain = irq_domain_add_linear(NULL, 1, &irq_domain_simple_ops, NULL);
428 	if (!adap->irq_domain)
429 		return -ENOMEM;
430 
431 	adap->client_irq = irq_create_mapping(adap->irq_domain, 0);
432 	if (!adap->client_irq) {
433 		ret = -ENOMEM;
434 		goto remove_irq_domain;
435 	}
436 
437 	irq_set_chip_data(adap->client_irq, adap);
438 	irq_set_chip_and_handler(adap->client_irq, &adap->irqchip,
439 				 handle_simple_irq);
440 
441 	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
442 					cht_wc_i2c_adap_thread_handler,
443 					IRQF_ONESHOT, "PMIC I2C Adapter", adap);
444 	if (ret)
445 		goto remove_irq_domain;
446 
447 	i2c_set_adapdata(&adap->adapter, adap);
448 	ret = i2c_add_adapter(&adap->adapter);
449 	if (ret)
450 		goto remove_irq_domain;
451 
452 	switch (pmic->cht_wc_model) {
453 	case INTEL_CHT_WC_GPD_WIN_POCKET:
454 		board_info = &gpd_win_board_info;
455 		break;
456 	case INTEL_CHT_WC_XIAOMI_MIPAD2:
457 		board_info = &xiaomi_mipad2_board_info;
458 		break;
459 	case INTEL_CHT_WC_LENOVO_YOGABOOK1:
460 		board_info = &lenovo_yogabook1_board_info;
461 		break;
462 	default:
463 		dev_warn(&pdev->dev, "Unknown model, not instantiating charger device\n");
464 		break;
465 	}
466 
467 	if (board_info) {
468 		board_info->irq = adap->client_irq;
469 		adap->client = i2c_new_client_device(&adap->adapter, board_info);
470 		if (IS_ERR(adap->client)) {
471 			ret = PTR_ERR(adap->client);
472 			goto del_adapter;
473 		}
474 	}
475 
476 	platform_set_drvdata(pdev, adap);
477 	return 0;
478 
479 del_adapter:
480 	i2c_del_adapter(&adap->adapter);
481 remove_irq_domain:
482 	irq_domain_remove(adap->irq_domain);
483 	return ret;
484 }
485 
486 static int cht_wc_i2c_adap_i2c_remove(struct platform_device *pdev)
487 {
488 	struct cht_wc_i2c_adap *adap = platform_get_drvdata(pdev);
489 
490 	i2c_unregister_device(adap->client);
491 	i2c_del_adapter(&adap->adapter);
492 	irq_domain_remove(adap->irq_domain);
493 
494 	return 0;
495 }
496 
497 static const struct platform_device_id cht_wc_i2c_adap_id_table[] = {
498 	{ .name = "cht_wcove_ext_chgr" },
499 	{},
500 };
501 MODULE_DEVICE_TABLE(platform, cht_wc_i2c_adap_id_table);
502 
503 static struct platform_driver cht_wc_i2c_adap_driver = {
504 	.probe = cht_wc_i2c_adap_i2c_probe,
505 	.remove = cht_wc_i2c_adap_i2c_remove,
506 	.driver = {
507 		.name = "cht_wcove_ext_chgr",
508 	},
509 	.id_table = cht_wc_i2c_adap_id_table,
510 };
511 module_platform_driver(cht_wc_i2c_adap_driver);
512 
513 MODULE_DESCRIPTION("Intel CHT Whiskey Cove PMIC I2C Master driver");
514 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
515 MODULE_LICENSE("GPL");
516