1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2011-2016 Synaptics Incorporated
4 * Copyright (c) 2011 Unixphere
5 */
6
7#include <linux/kernel.h>
8#include <linux/device.h>
9#include <linux/irq.h>
10#include <linux/irqdomain.h>
11#include <linux/list.h>
12#include <linux/pm.h>
13#include <linux/rmi.h>
14#include <linux/slab.h>
15#include <linux/types.h>
16#include <linux/of.h>
17#include "rmi_bus.h"
18#include "rmi_driver.h"
19
20static int debug_flags;
21module_param(debug_flags, int, 0644);
22MODULE_PARM_DESC(debug_flags, "control debugging information");
23
24void rmi_dbg(int flags, struct device *dev, const char *fmt, ...)
25{
26	struct va_format vaf;
27	va_list args;
28
29	if (flags & debug_flags) {
30		va_start(args, fmt);
31
32		vaf.fmt = fmt;
33		vaf.va = &args;
34
35		dev_printk(KERN_DEBUG, dev, "%pV", &vaf);
36
37		va_end(args);
38	}
39}
40EXPORT_SYMBOL_GPL(rmi_dbg);
41
42/*
43 * RMI Physical devices
44 *
45 * Physical RMI device consists of several functions serving particular
46 * purpose. For example F11 is a 2D touch sensor while F01 is a generic
47 * function present in every RMI device.
48 */
49
50static void rmi_release_device(struct device *dev)
51{
52	struct rmi_device *rmi_dev = to_rmi_device(dev);
53
54	kfree(rmi_dev);
55}
56
57static const struct device_type rmi_device_type = {
58	.name		= "rmi4_sensor",
59	.release	= rmi_release_device,
60};
61
62bool rmi_is_physical_device(struct device *dev)
63{
64	return dev->type == &rmi_device_type;
65}
66
67/**
68 * rmi_register_transport_device - register a transport device connection
69 * on the RMI bus.  Transport drivers provide communication from the devices
70 * on a bus (such as SPI, I2C, and so on) to the RMI4 sensor.
71 *
72 * @xport: the transport device to register
73 */
74int rmi_register_transport_device(struct rmi_transport_dev *xport)
75{
76	static atomic_t transport_device_count = ATOMIC_INIT(0);
77	struct rmi_device *rmi_dev;
78	int error;
79
80	rmi_dev = kzalloc(sizeof(struct rmi_device), GFP_KERNEL);
81	if (!rmi_dev)
82		return -ENOMEM;
83
84	device_initialize(&rmi_dev->dev);
85
86	rmi_dev->xport = xport;
87	rmi_dev->number = atomic_inc_return(&transport_device_count) - 1;
88
89	dev_set_name(&rmi_dev->dev, "rmi4-%02d", rmi_dev->number);
90
91	rmi_dev->dev.bus = &rmi_bus_type;
92	rmi_dev->dev.type = &rmi_device_type;
93	rmi_dev->dev.parent = xport->dev;
94
95	xport->rmi_dev = rmi_dev;
96
97	error = device_add(&rmi_dev->dev);
98	if (error)
99		goto err_put_device;
100
101	rmi_dbg(RMI_DEBUG_CORE, xport->dev,
102		"%s: Registered %s as %s.\n", __func__,
103		dev_name(rmi_dev->xport->dev), dev_name(&rmi_dev->dev));
104
105	return 0;
106
107err_put_device:
108	put_device(&rmi_dev->dev);
109	return error;
110}
111EXPORT_SYMBOL_GPL(rmi_register_transport_device);
112
113/**
114 * rmi_unregister_transport_device - unregister a transport device connection
115 * @xport: the transport driver to unregister
116 *
117 */
118void rmi_unregister_transport_device(struct rmi_transport_dev *xport)
119{
120	struct rmi_device *rmi_dev = xport->rmi_dev;
121
122	device_del(&rmi_dev->dev);
123	put_device(&rmi_dev->dev);
124}
125EXPORT_SYMBOL(rmi_unregister_transport_device);
126
127
128/* Function specific stuff */
129
130static void rmi_release_function(struct device *dev)
131{
132	struct rmi_function *fn = to_rmi_function(dev);
133
134	kfree(fn);
135}
136
137static const struct device_type rmi_function_type = {
138	.name		= "rmi4_function",
139	.release	= rmi_release_function,
140};
141
142bool rmi_is_function_device(struct device *dev)
143{
144	return dev->type == &rmi_function_type;
145}
146
147static int rmi_function_match(struct device *dev, struct device_driver *drv)
148{
149	struct rmi_function_handler *handler = to_rmi_function_handler(drv);
150	struct rmi_function *fn = to_rmi_function(dev);
151
152	return fn->fd.function_number == handler->func;
153}
154
155#ifdef CONFIG_OF
156static void rmi_function_of_probe(struct rmi_function *fn)
157{
158	char of_name[9];
159	struct device_node *node = fn->rmi_dev->xport->dev->of_node;
160
161	snprintf(of_name, sizeof(of_name), "rmi4-f%02x",
162		fn->fd.function_number);
163	fn->dev.of_node = of_get_child_by_name(node, of_name);
164}
165#else
166static inline void rmi_function_of_probe(struct rmi_function *fn)
167{}
168#endif
169
170static struct irq_chip rmi_irq_chip = {
171	.name = "rmi4",
172};
173
174static int rmi_create_function_irq(struct rmi_function *fn,
175				   struct rmi_function_handler *handler)
176{
177	struct rmi_driver_data *drvdata = dev_get_drvdata(&fn->rmi_dev->dev);
178	int i, error;
179
180	for (i = 0; i < fn->num_of_irqs; i++) {
181		set_bit(fn->irq_pos + i, fn->irq_mask);
182
183		fn->irq[i] = irq_create_mapping(drvdata->irqdomain,
184						fn->irq_pos + i);
185
186		irq_set_chip_data(fn->irq[i], fn);
187		irq_set_chip_and_handler(fn->irq[i], &rmi_irq_chip,
188					 handle_simple_irq);
189		irq_set_nested_thread(fn->irq[i], 1);
190
191		error = devm_request_threaded_irq(&fn->dev, fn->irq[i], NULL,
192					handler->attention, IRQF_ONESHOT,
193					dev_name(&fn->dev), fn);
194		if (error) {
195			dev_err(&fn->dev, "Error %d registering IRQ\n", error);
196			return error;
197		}
198	}
199
200	return 0;
201}
202
203static int rmi_function_probe(struct device *dev)
204{
205	struct rmi_function *fn = to_rmi_function(dev);
206	struct rmi_function_handler *handler =
207					to_rmi_function_handler(dev->driver);
208	int error;
209
210	rmi_function_of_probe(fn);
211
212	if (handler->probe) {
213		error = handler->probe(fn);
214		if (error)
215			return error;
216	}
217
218	if (fn->num_of_irqs && handler->attention) {
219		error = rmi_create_function_irq(fn, handler);
220		if (error)
221			return error;
222	}
223
224	return 0;
225}
226
227static int rmi_function_remove(struct device *dev)
228{
229	struct rmi_function *fn = to_rmi_function(dev);
230	struct rmi_function_handler *handler =
231					to_rmi_function_handler(dev->driver);
232
233	if (handler->remove)
234		handler->remove(fn);
235
236	return 0;
237}
238
239int rmi_register_function(struct rmi_function *fn)
240{
241	struct rmi_device *rmi_dev = fn->rmi_dev;
242	int error;
243
244	device_initialize(&fn->dev);
245
246	dev_set_name(&fn->dev, "%s.fn%02x",
247		     dev_name(&rmi_dev->dev), fn->fd.function_number);
248
249	fn->dev.parent = &rmi_dev->dev;
250	fn->dev.type = &rmi_function_type;
251	fn->dev.bus = &rmi_bus_type;
252
253	error = device_add(&fn->dev);
254	if (error) {
255		dev_err(&rmi_dev->dev,
256			"Failed device_register function device %s\n",
257			dev_name(&fn->dev));
258		goto err_put_device;
259	}
260
261	rmi_dbg(RMI_DEBUG_CORE, &rmi_dev->dev, "Registered F%02X.\n",
262			fn->fd.function_number);
263
264	return 0;
265
266err_put_device:
267	put_device(&fn->dev);
268	return error;
269}
270
271void rmi_unregister_function(struct rmi_function *fn)
272{
273	int i;
274
275	rmi_dbg(RMI_DEBUG_CORE, &fn->dev, "Unregistering F%02X.\n",
276			fn->fd.function_number);
277
278	device_del(&fn->dev);
279	of_node_put(fn->dev.of_node);
280
281	for (i = 0; i < fn->num_of_irqs; i++)
282		irq_dispose_mapping(fn->irq[i]);
283
284	put_device(&fn->dev);
285}
286
287/**
288 * __rmi_register_function_handler - register a handler for an RMI function
289 * @handler: RMI handler that should be registered.
290 * @owner: pointer to module that implements the handler
291 * @mod_name: name of the module implementing the handler
292 *
293 * This function performs additional setup of RMI function handler and
294 * registers it with the RMI core so that it can be bound to
295 * RMI function devices.
296 */
297int __rmi_register_function_handler(struct rmi_function_handler *handler,
298				     struct module *owner,
299				     const char *mod_name)
300{
301	struct device_driver *driver = &handler->driver;
302	int error;
303
304	driver->bus = &rmi_bus_type;
305	driver->owner = owner;
306	driver->mod_name = mod_name;
307	driver->probe = rmi_function_probe;
308	driver->remove = rmi_function_remove;
309
310	error = driver_register(driver);
311	if (error) {
312		pr_err("driver_register() failed for %s, error: %d\n",
313			driver->name, error);
314		return error;
315	}
316
317	return 0;
318}
319EXPORT_SYMBOL_GPL(__rmi_register_function_handler);
320
321/**
322 * rmi_unregister_function_handler - unregister given RMI function handler
323 * @handler: RMI handler that should be unregistered.
324 *
325 * This function unregisters given function handler from RMI core which
326 * causes it to be unbound from the function devices.
327 */
328void rmi_unregister_function_handler(struct rmi_function_handler *handler)
329{
330	driver_unregister(&handler->driver);
331}
332EXPORT_SYMBOL_GPL(rmi_unregister_function_handler);
333
334/* Bus specific stuff */
335
336static int rmi_bus_match(struct device *dev, struct device_driver *drv)
337{
338	bool physical = rmi_is_physical_device(dev);
339
340	/* First see if types are not compatible */
341	if (physical != rmi_is_physical_driver(drv))
342		return 0;
343
344	return physical || rmi_function_match(dev, drv);
345}
346
347const struct bus_type rmi_bus_type = {
348	.match		= rmi_bus_match,
349	.name		= "rmi4",
350};
351
352static struct rmi_function_handler *fn_handlers[] = {
353	&rmi_f01_handler,
354#ifdef CONFIG_RMI4_F03
355	&rmi_f03_handler,
356#endif
357#ifdef CONFIG_RMI4_F11
358	&rmi_f11_handler,
359#endif
360#ifdef CONFIG_RMI4_F12
361	&rmi_f12_handler,
362#endif
363#ifdef CONFIG_RMI4_F30
364	&rmi_f30_handler,
365#endif
366#ifdef CONFIG_RMI4_F34
367	&rmi_f34_handler,
368#endif
369#ifdef CONFIG_RMI4_F3A
370	&rmi_f3a_handler,
371#endif
372#ifdef CONFIG_RMI4_F54
373	&rmi_f54_handler,
374#endif
375#ifdef CONFIG_RMI4_F55
376	&rmi_f55_handler,
377#endif
378};
379
380static void __rmi_unregister_function_handlers(int start_idx)
381{
382	int i;
383
384	for (i = start_idx; i >= 0; i--)
385		rmi_unregister_function_handler(fn_handlers[i]);
386}
387
388static void rmi_unregister_function_handlers(void)
389{
390	__rmi_unregister_function_handlers(ARRAY_SIZE(fn_handlers) - 1);
391}
392
393static int rmi_register_function_handlers(void)
394{
395	int ret;
396	int i;
397
398	for (i = 0; i < ARRAY_SIZE(fn_handlers); i++)	{
399		ret = rmi_register_function_handler(fn_handlers[i]);
400		if (ret) {
401			pr_err("%s: error registering the RMI F%02x handler: %d\n",
402				__func__, fn_handlers[i]->func, ret);
403			goto err_unregister_function_handlers;
404		}
405	}
406
407	return 0;
408
409err_unregister_function_handlers:
410	__rmi_unregister_function_handlers(i - 1);
411	return ret;
412}
413
414int rmi_of_property_read_u32(struct device *dev, u32 *result,
415				const char *prop, bool optional)
416{
417	int retval;
418	u32 val = 0;
419
420	retval = of_property_read_u32(dev->of_node, prop, &val);
421	if (retval && (!optional && retval == -EINVAL)) {
422		dev_err(dev, "Failed to get %s value: %d\n",
423			prop, retval);
424		return retval;
425	}
426	*result = val;
427
428	return 0;
429}
430EXPORT_SYMBOL_GPL(rmi_of_property_read_u32);
431
432static int __init rmi_bus_init(void)
433{
434	int error;
435
436	error = bus_register(&rmi_bus_type);
437	if (error) {
438		pr_err("%s: error registering the RMI bus: %d\n",
439			__func__, error);
440		return error;
441	}
442
443	error = rmi_register_function_handlers();
444	if (error)
445		goto err_unregister_bus;
446
447	error = rmi_register_physical_driver();
448	if (error) {
449		pr_err("%s: error registering the RMI physical driver: %d\n",
450			__func__, error);
451		goto err_unregister_bus;
452	}
453
454	return 0;
455
456err_unregister_bus:
457	bus_unregister(&rmi_bus_type);
458	return error;
459}
460module_init(rmi_bus_init);
461
462static void __exit rmi_bus_exit(void)
463{
464	/*
465	 * We should only ever get here if all drivers are unloaded, so
466	 * all we have to do at this point is unregister ourselves.
467	 */
468
469	rmi_unregister_physical_driver();
470	rmi_unregister_function_handlers();
471	bus_unregister(&rmi_bus_type);
472}
473module_exit(rmi_bus_exit);
474
475MODULE_AUTHOR("Christopher Heiny <cheiny@synaptics.com");
476MODULE_AUTHOR("Andrew Duggan <aduggan@synaptics.com");
477MODULE_DESCRIPTION("RMI bus");
478MODULE_LICENSE("GPL");
479