xref: /linux/drivers/i2c/busses/i2c-cht-wc.c (revision 3c53c6255d598db7084c5c3d7553d7200e857818)
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/slab.h>
22 
23 #define CHT_WC_I2C_CTRL			0x5e24
24 #define CHT_WC_I2C_CTRL_WR		BIT(0)
25 #define CHT_WC_I2C_CTRL_RD		BIT(1)
26 #define CHT_WC_I2C_CLIENT_ADDR		0x5e25
27 #define CHT_WC_I2C_REG_OFFSET		0x5e26
28 #define CHT_WC_I2C_WRDATA		0x5e27
29 #define CHT_WC_I2C_RDDATA		0x5e28
30 
31 #define CHT_WC_EXTCHGRIRQ		0x6e0a
32 #define CHT_WC_EXTCHGRIRQ_CLIENT_IRQ	BIT(0)
33 #define CHT_WC_EXTCHGRIRQ_WRITE_IRQ	BIT(1)
34 #define CHT_WC_EXTCHGRIRQ_READ_IRQ	BIT(2)
35 #define CHT_WC_EXTCHGRIRQ_NACK_IRQ	BIT(3)
36 #define CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK	((u8)GENMASK(3, 1))
37 #define CHT_WC_EXTCHGRIRQ_MSK		0x6e17
38 
39 struct cht_wc_i2c_adap {
40 	struct i2c_adapter adapter;
41 	wait_queue_head_t wait;
42 	struct irq_chip irqchip;
43 	struct mutex adap_lock;
44 	struct mutex irqchip_lock;
45 	struct regmap *regmap;
46 	struct irq_domain *irq_domain;
47 	struct i2c_client *client;
48 	int client_irq;
49 	u8 irq_mask;
50 	u8 old_irq_mask;
51 	int read_data;
52 	bool io_error;
53 	bool done;
54 };
55 
56 static irqreturn_t cht_wc_i2c_adap_thread_handler(int id, void *data)
57 {
58 	struct cht_wc_i2c_adap *adap = data;
59 	int ret, reg;
60 
61 	mutex_lock(&adap->adap_lock);
62 
63 	/* Read IRQs */
64 	ret = regmap_read(adap->regmap, CHT_WC_EXTCHGRIRQ, &reg);
65 	if (ret) {
66 		dev_err(&adap->adapter.dev, "Error reading extchgrirq reg\n");
67 		mutex_unlock(&adap->adap_lock);
68 		return IRQ_NONE;
69 	}
70 
71 	reg &= ~adap->irq_mask;
72 
73 	/* Reads must be acked after reading the received data. */
74 	ret = regmap_read(adap->regmap, CHT_WC_I2C_RDDATA, &adap->read_data);
75 	if (ret)
76 		adap->io_error = true;
77 
78 	/*
79 	 * Immediately ack IRQs, so that if new IRQs arrives while we're
80 	 * handling the previous ones our irq will re-trigger when we're done.
81 	 */
82 	ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ, reg);
83 	if (ret)
84 		dev_err(&adap->adapter.dev, "Error writing extchgrirq reg\n");
85 
86 	if (reg & CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK) {
87 		adap->io_error |= !!(reg & CHT_WC_EXTCHGRIRQ_NACK_IRQ);
88 		adap->done = true;
89 	}
90 
91 	mutex_unlock(&adap->adap_lock);
92 
93 	if (reg & CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK)
94 		wake_up(&adap->wait);
95 
96 	/*
97 	 * Do NOT use handle_nested_irq here, the client irq handler will
98 	 * likely want to do i2c transfers and the i2c controller uses this
99 	 * interrupt handler as well, so running the client irq handler from
100 	 * this thread will cause things to lock up.
101 	 */
102 	if (reg & CHT_WC_EXTCHGRIRQ_CLIENT_IRQ) {
103 		/*
104 		 * generic_handle_irq expects local IRQs to be disabled
105 		 * as normally it is called from interrupt context.
106 		 */
107 		local_irq_disable();
108 		generic_handle_irq(adap->client_irq);
109 		local_irq_enable();
110 	}
111 
112 	return IRQ_HANDLED;
113 }
114 
115 static u32 cht_wc_i2c_adap_master_func(struct i2c_adapter *adap)
116 {
117 	/* This i2c adapter only supports SMBUS byte transfers */
118 	return I2C_FUNC_SMBUS_BYTE_DATA;
119 }
120 
121 static int cht_wc_i2c_adap_smbus_xfer(struct i2c_adapter *_adap, u16 addr,
122 				      unsigned short flags, char read_write,
123 				      u8 command, int size,
124 				      union i2c_smbus_data *data)
125 {
126 	struct cht_wc_i2c_adap *adap = i2c_get_adapdata(_adap);
127 	int ret;
128 
129 	mutex_lock(&adap->adap_lock);
130 	adap->io_error = false;
131 	adap->done = false;
132 	mutex_unlock(&adap->adap_lock);
133 
134 	ret = regmap_write(adap->regmap, CHT_WC_I2C_CLIENT_ADDR, addr);
135 	if (ret)
136 		return ret;
137 
138 	if (read_write == I2C_SMBUS_WRITE) {
139 		ret = regmap_write(adap->regmap, CHT_WC_I2C_WRDATA, data->byte);
140 		if (ret)
141 			return ret;
142 	}
143 
144 	ret = regmap_write(adap->regmap, CHT_WC_I2C_REG_OFFSET, command);
145 	if (ret)
146 		return ret;
147 
148 	ret = regmap_write(adap->regmap, CHT_WC_I2C_CTRL,
149 			   (read_write == I2C_SMBUS_WRITE) ?
150 			   CHT_WC_I2C_CTRL_WR : CHT_WC_I2C_CTRL_RD);
151 	if (ret)
152 		return ret;
153 
154 	ret = wait_event_timeout(adap->wait, adap->done, msecs_to_jiffies(30));
155 	if (ret == 0) {
156 		/*
157 		 * The CHT GPIO controller serializes all IRQs, sometimes
158 		 * causing significant delays, check status manually.
159 		 */
160 		cht_wc_i2c_adap_thread_handler(0, adap);
161 		if (!adap->done)
162 			return -ETIMEDOUT;
163 	}
164 
165 	ret = 0;
166 	mutex_lock(&adap->adap_lock);
167 	if (adap->io_error)
168 		ret = -EIO;
169 	else if (read_write == I2C_SMBUS_READ)
170 		data->byte = adap->read_data;
171 	mutex_unlock(&adap->adap_lock);
172 
173 	return ret;
174 }
175 
176 static const struct i2c_algorithm cht_wc_i2c_adap_algo = {
177 	.functionality = cht_wc_i2c_adap_master_func,
178 	.smbus_xfer = cht_wc_i2c_adap_smbus_xfer,
179 };
180 
181 /**** irqchip for the client connected to the extchgr i2c adapter ****/
182 static void cht_wc_i2c_irq_lock(struct irq_data *data)
183 {
184 	struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data);
185 
186 	mutex_lock(&adap->irqchip_lock);
187 }
188 
189 static void cht_wc_i2c_irq_sync_unlock(struct irq_data *data)
190 {
191 	struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data);
192 	int ret;
193 
194 	if (adap->irq_mask != adap->old_irq_mask) {
195 		ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ_MSK,
196 				   adap->irq_mask);
197 		if (ret == 0)
198 			adap->old_irq_mask = adap->irq_mask;
199 		else
200 			dev_err(&adap->adapter.dev, "Error writing EXTCHGRIRQ_MSK\n");
201 	}
202 
203 	mutex_unlock(&adap->irqchip_lock);
204 }
205 
206 static void cht_wc_i2c_irq_enable(struct irq_data *data)
207 {
208 	struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data);
209 
210 	adap->irq_mask &= ~CHT_WC_EXTCHGRIRQ_CLIENT_IRQ;
211 }
212 
213 static void cht_wc_i2c_irq_disable(struct irq_data *data)
214 {
215 	struct cht_wc_i2c_adap *adap = irq_data_get_irq_chip_data(data);
216 
217 	adap->irq_mask |= CHT_WC_EXTCHGRIRQ_CLIENT_IRQ;
218 }
219 
220 static const struct irq_chip cht_wc_i2c_irq_chip = {
221 	.irq_bus_lock		= cht_wc_i2c_irq_lock,
222 	.irq_bus_sync_unlock	= cht_wc_i2c_irq_sync_unlock,
223 	.irq_disable		= cht_wc_i2c_irq_disable,
224 	.irq_enable		= cht_wc_i2c_irq_enable,
225 	.name			= "cht_wc_ext_chrg_irq_chip",
226 };
227 
228 static const char * const bq24190_suppliers[] = {
229 	"tcpm-source-psy-i2c-fusb302" };
230 
231 static const struct property_entry bq24190_props[] = {
232 	PROPERTY_ENTRY_STRING_ARRAY("supplied-from", bq24190_suppliers),
233 	PROPERTY_ENTRY_BOOL("omit-battery-class"),
234 	PROPERTY_ENTRY_BOOL("disable-reset"),
235 	{ }
236 };
237 
238 static struct regulator_consumer_supply fusb302_consumer = {
239 	.supply = "vbus",
240 	/* Must match fusb302 dev_name in intel_cht_int33fe.c */
241 	.dev_name = "i2c-fusb302",
242 };
243 
244 static const struct regulator_init_data bq24190_vbus_init_data = {
245 	.constraints = {
246 		/* The name is used in intel_cht_int33fe.c do not change. */
247 		.name = "cht_wc_usb_typec_vbus",
248 		.valid_ops_mask = REGULATOR_CHANGE_STATUS,
249 	},
250 	.consumer_supplies = &fusb302_consumer,
251 	.num_consumer_supplies = 1,
252 };
253 
254 static struct bq24190_platform_data bq24190_pdata = {
255 	.regulator_init_data = &bq24190_vbus_init_data,
256 };
257 
258 static int cht_wc_i2c_adap_i2c_probe(struct platform_device *pdev)
259 {
260 	struct intel_soc_pmic *pmic = dev_get_drvdata(pdev->dev.parent);
261 	struct cht_wc_i2c_adap *adap;
262 	struct i2c_board_info board_info = {
263 		.type = "bq24190",
264 		.addr = 0x6b,
265 		.dev_name = "bq24190",
266 		.properties = bq24190_props,
267 		.platform_data = &bq24190_pdata,
268 	};
269 	int ret, reg, irq;
270 
271 	irq = platform_get_irq(pdev, 0);
272 	if (irq < 0) {
273 		dev_err(&pdev->dev, "Error missing irq resource\n");
274 		return -EINVAL;
275 	}
276 
277 	adap = devm_kzalloc(&pdev->dev, sizeof(*adap), GFP_KERNEL);
278 	if (!adap)
279 		return -ENOMEM;
280 
281 	init_waitqueue_head(&adap->wait);
282 	mutex_init(&adap->adap_lock);
283 	mutex_init(&adap->irqchip_lock);
284 	adap->irqchip = cht_wc_i2c_irq_chip;
285 	adap->regmap = pmic->regmap;
286 	adap->adapter.owner = THIS_MODULE;
287 	adap->adapter.class = I2C_CLASS_HWMON;
288 	adap->adapter.algo = &cht_wc_i2c_adap_algo;
289 	strlcpy(adap->adapter.name, "PMIC I2C Adapter",
290 		sizeof(adap->adapter.name));
291 	adap->adapter.dev.parent = &pdev->dev;
292 
293 	/* Clear and activate i2c-adapter interrupts, disable client IRQ */
294 	adap->old_irq_mask = adap->irq_mask = ~CHT_WC_EXTCHGRIRQ_ADAP_IRQMASK;
295 
296 	ret = regmap_read(adap->regmap, CHT_WC_I2C_RDDATA, &reg);
297 	if (ret)
298 		return ret;
299 
300 	ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ, ~adap->irq_mask);
301 	if (ret)
302 		return ret;
303 
304 	ret = regmap_write(adap->regmap, CHT_WC_EXTCHGRIRQ_MSK, adap->irq_mask);
305 	if (ret)
306 		return ret;
307 
308 	/* Alloc and register client IRQ */
309 	adap->irq_domain = irq_domain_add_linear(pdev->dev.of_node, 1,
310 						 &irq_domain_simple_ops, NULL);
311 	if (!adap->irq_domain)
312 		return -ENOMEM;
313 
314 	adap->client_irq = irq_create_mapping(adap->irq_domain, 0);
315 	if (!adap->client_irq) {
316 		ret = -ENOMEM;
317 		goto remove_irq_domain;
318 	}
319 
320 	irq_set_chip_data(adap->client_irq, adap);
321 	irq_set_chip_and_handler(adap->client_irq, &adap->irqchip,
322 				 handle_simple_irq);
323 
324 	ret = devm_request_threaded_irq(&pdev->dev, irq, NULL,
325 					cht_wc_i2c_adap_thread_handler,
326 					IRQF_ONESHOT, "PMIC I2C Adapter", adap);
327 	if (ret)
328 		goto remove_irq_domain;
329 
330 	i2c_set_adapdata(&adap->adapter, adap);
331 	ret = i2c_add_adapter(&adap->adapter);
332 	if (ret)
333 		goto remove_irq_domain;
334 
335 	/*
336 	 * Normally the Whiskey Cove PMIC is paired with a TI bq24292i charger,
337 	 * connected to this i2c bus, and a max17047 fuel-gauge and a fusb302
338 	 * USB Type-C controller connected to another i2c bus. In this setup
339 	 * the max17047 and fusb302 devices are enumerated through an INT33FE
340 	 * ACPI device. If this device is present register an i2c-client for
341 	 * the TI bq24292i charger.
342 	 */
343 	if (acpi_dev_present("INT33FE", NULL, -1)) {
344 		board_info.irq = adap->client_irq;
345 		adap->client = i2c_new_device(&adap->adapter, &board_info);
346 		if (!adap->client) {
347 			ret = -ENOMEM;
348 			goto del_adapter;
349 		}
350 	}
351 
352 	platform_set_drvdata(pdev, adap);
353 	return 0;
354 
355 del_adapter:
356 	i2c_del_adapter(&adap->adapter);
357 remove_irq_domain:
358 	irq_domain_remove(adap->irq_domain);
359 	return ret;
360 }
361 
362 static int cht_wc_i2c_adap_i2c_remove(struct platform_device *pdev)
363 {
364 	struct cht_wc_i2c_adap *adap = platform_get_drvdata(pdev);
365 
366 	if (adap->client)
367 		i2c_unregister_device(adap->client);
368 	i2c_del_adapter(&adap->adapter);
369 	irq_domain_remove(adap->irq_domain);
370 
371 	return 0;
372 }
373 
374 static const struct platform_device_id cht_wc_i2c_adap_id_table[] = {
375 	{ .name = "cht_wcove_ext_chgr" },
376 	{},
377 };
378 MODULE_DEVICE_TABLE(platform, cht_wc_i2c_adap_id_table);
379 
380 static struct platform_driver cht_wc_i2c_adap_driver = {
381 	.probe = cht_wc_i2c_adap_i2c_probe,
382 	.remove = cht_wc_i2c_adap_i2c_remove,
383 	.driver = {
384 		.name = "cht_wcove_ext_chgr",
385 	},
386 	.id_table = cht_wc_i2c_adap_id_table,
387 };
388 module_platform_driver(cht_wc_i2c_adap_driver);
389 
390 MODULE_DESCRIPTION("Intel CHT Whiskey Cove PMIC I2C Master driver");
391 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
392 MODULE_LICENSE("GPL");
393