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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright (c) 2012-2015, The Linux Foundation. All rights reserved.
4 */
5#include <linux/kernel.h>
6#include <linux/errno.h>
7#include <linux/idr.h>
8#include <linux/slab.h>
9#include <linux/module.h>
10#include <linux/of.h>
11#include <linux/of_device.h>
12#include <linux/platform_device.h>
13#include <linux/spmi.h>
14#include <linux/pm_runtime.h>
15
16#include <dt-bindings/spmi/spmi.h>
17#define CREATE_TRACE_POINTS
18#include <trace/events/spmi.h>
19
20static bool is_registered;
21static DEFINE_IDA(ctrl_ida);
22
23static void spmi_dev_release(struct device *dev)
24{
25 struct spmi_device *sdev = to_spmi_device(dev);
26
27 kfree(sdev);
28}
29
30static const struct device_type spmi_dev_type = {
31 .release = spmi_dev_release,
32};
33
34static void spmi_ctrl_release(struct device *dev)
35{
36 struct spmi_controller *ctrl = to_spmi_controller(dev);
37
38 ida_free(&ctrl_ida, ctrl->nr);
39 kfree(ctrl);
40}
41
42static const struct device_type spmi_ctrl_type = {
43 .release = spmi_ctrl_release,
44};
45
46static int spmi_device_match(struct device *dev, const struct device_driver *drv)
47{
48 if (of_driver_match_device(dev, drv))
49 return 1;
50
51 if (drv->name)
52 return strncmp(dev_name(dev), drv->name,
53 SPMI_NAME_SIZE) == 0;
54
55 return 0;
56}
57
58/**
59 * spmi_device_add() - add a device previously constructed via spmi_device_alloc()
60 * @sdev: spmi_device to be added
61 */
62int spmi_device_add(struct spmi_device *sdev)
63{
64 struct spmi_controller *ctrl = sdev->ctrl;
65 int err;
66
67 dev_set_name(&sdev->dev, "%d-%02x", ctrl->nr, sdev->usid);
68
69 err = device_add(&sdev->dev);
70 if (err < 0) {
71 dev_err(&sdev->dev, "Can't add %s, status %d\n",
72 dev_name(&sdev->dev), err);
73 goto err_device_add;
74 }
75
76 dev_dbg(&sdev->dev, "device %s registered\n", dev_name(&sdev->dev));
77
78err_device_add:
79 return err;
80}
81EXPORT_SYMBOL_GPL(spmi_device_add);
82
83/**
84 * spmi_device_remove(): remove an SPMI device
85 * @sdev: spmi_device to be removed
86 */
87void spmi_device_remove(struct spmi_device *sdev)
88{
89 device_unregister(&sdev->dev);
90}
91EXPORT_SYMBOL_GPL(spmi_device_remove);
92
93static inline int
94spmi_cmd(struct spmi_controller *ctrl, u8 opcode, u8 sid)
95{
96 int ret;
97
98 if (!ctrl || !ctrl->cmd || ctrl->dev.type != &spmi_ctrl_type)
99 return -EINVAL;
100
101 ret = ctrl->cmd(ctrl, opcode, sid);
102 trace_spmi_cmd(opcode, sid, ret);
103 return ret;
104}
105
106static inline int spmi_read_cmd(struct spmi_controller *ctrl, u8 opcode,
107 u8 sid, u16 addr, u8 *buf, size_t len)
108{
109 int ret;
110
111 if (!ctrl || !ctrl->read_cmd || ctrl->dev.type != &spmi_ctrl_type)
112 return -EINVAL;
113
114 trace_spmi_read_begin(opcode, sid, addr);
115 ret = ctrl->read_cmd(ctrl, opcode, sid, addr, buf, len);
116 trace_spmi_read_end(opcode, sid, addr, ret, len, buf);
117 return ret;
118}
119
120static inline int spmi_write_cmd(struct spmi_controller *ctrl, u8 opcode,
121 u8 sid, u16 addr, const u8 *buf, size_t len)
122{
123 int ret;
124
125 if (!ctrl || !ctrl->write_cmd || ctrl->dev.type != &spmi_ctrl_type)
126 return -EINVAL;
127
128 trace_spmi_write_begin(opcode, sid, addr, len, buf);
129 ret = ctrl->write_cmd(ctrl, opcode, sid, addr, buf, len);
130 trace_spmi_write_end(opcode, sid, addr, ret);
131 return ret;
132}
133
134/**
135 * spmi_register_read() - register read
136 * @sdev: SPMI device.
137 * @addr: slave register address (5-bit address).
138 * @buf: buffer to be populated with data from the Slave.
139 *
140 * Reads 1 byte of data from a Slave device register.
141 */
142int spmi_register_read(struct spmi_device *sdev, u8 addr, u8 *buf)
143{
144 /* 5-bit register address */
145 if (addr > 0x1F)
146 return -EINVAL;
147
148 return spmi_read_cmd(sdev->ctrl, SPMI_CMD_READ, sdev->usid, addr,
149 buf, 1);
150}
151EXPORT_SYMBOL_GPL(spmi_register_read);
152
153/**
154 * spmi_ext_register_read() - extended register read
155 * @sdev: SPMI device.
156 * @addr: slave register address (8-bit address).
157 * @buf: buffer to be populated with data from the Slave.
158 * @len: the request number of bytes to read (up to 16 bytes).
159 *
160 * Reads up to 16 bytes of data from the extended register space on a
161 * Slave device.
162 */
163int spmi_ext_register_read(struct spmi_device *sdev, u8 addr, u8 *buf,
164 size_t len)
165{
166 /* 8-bit register address, up to 16 bytes */
167 if (len == 0 || len > 16)
168 return -EINVAL;
169
170 return spmi_read_cmd(sdev->ctrl, SPMI_CMD_EXT_READ, sdev->usid, addr,
171 buf, len);
172}
173EXPORT_SYMBOL_GPL(spmi_ext_register_read);
174
175/**
176 * spmi_ext_register_readl() - extended register read long
177 * @sdev: SPMI device.
178 * @addr: slave register address (16-bit address).
179 * @buf: buffer to be populated with data from the Slave.
180 * @len: the request number of bytes to read (up to 8 bytes).
181 *
182 * Reads up to 8 bytes of data from the extended register space on a
183 * Slave device using 16-bit address.
184 */
185int spmi_ext_register_readl(struct spmi_device *sdev, u16 addr, u8 *buf,
186 size_t len)
187{
188 /* 16-bit register address, up to 8 bytes */
189 if (len == 0 || len > 8)
190 return -EINVAL;
191
192 return spmi_read_cmd(sdev->ctrl, SPMI_CMD_EXT_READL, sdev->usid, addr,
193 buf, len);
194}
195EXPORT_SYMBOL_GPL(spmi_ext_register_readl);
196
197/**
198 * spmi_register_write() - register write
199 * @sdev: SPMI device
200 * @addr: slave register address (5-bit address).
201 * @data: buffer containing the data to be transferred to the Slave.
202 *
203 * Writes 1 byte of data to a Slave device register.
204 */
205int spmi_register_write(struct spmi_device *sdev, u8 addr, u8 data)
206{
207 /* 5-bit register address */
208 if (addr > 0x1F)
209 return -EINVAL;
210
211 return spmi_write_cmd(sdev->ctrl, SPMI_CMD_WRITE, sdev->usid, addr,
212 &data, 1);
213}
214EXPORT_SYMBOL_GPL(spmi_register_write);
215
216/**
217 * spmi_register_zero_write() - register zero write
218 * @sdev: SPMI device.
219 * @data: the data to be written to register 0 (7-bits).
220 *
221 * Writes data to register 0 of the Slave device.
222 */
223int spmi_register_zero_write(struct spmi_device *sdev, u8 data)
224{
225 return spmi_write_cmd(sdev->ctrl, SPMI_CMD_ZERO_WRITE, sdev->usid, 0,
226 &data, 1);
227}
228EXPORT_SYMBOL_GPL(spmi_register_zero_write);
229
230/**
231 * spmi_ext_register_write() - extended register write
232 * @sdev: SPMI device.
233 * @addr: slave register address (8-bit address).
234 * @buf: buffer containing the data to be transferred to the Slave.
235 * @len: the request number of bytes to read (up to 16 bytes).
236 *
237 * Writes up to 16 bytes of data to the extended register space of a
238 * Slave device.
239 */
240int spmi_ext_register_write(struct spmi_device *sdev, u8 addr, const u8 *buf,
241 size_t len)
242{
243 /* 8-bit register address, up to 16 bytes */
244 if (len == 0 || len > 16)
245 return -EINVAL;
246
247 return spmi_write_cmd(sdev->ctrl, SPMI_CMD_EXT_WRITE, sdev->usid, addr,
248 buf, len);
249}
250EXPORT_SYMBOL_GPL(spmi_ext_register_write);
251
252/**
253 * spmi_ext_register_writel() - extended register write long
254 * @sdev: SPMI device.
255 * @addr: slave register address (16-bit address).
256 * @buf: buffer containing the data to be transferred to the Slave.
257 * @len: the request number of bytes to read (up to 8 bytes).
258 *
259 * Writes up to 8 bytes of data to the extended register space of a
260 * Slave device using 16-bit address.
261 */
262int spmi_ext_register_writel(struct spmi_device *sdev, u16 addr, const u8 *buf,
263 size_t len)
264{
265 /* 4-bit Slave Identifier, 16-bit register address, up to 8 bytes */
266 if (len == 0 || len > 8)
267 return -EINVAL;
268
269 return spmi_write_cmd(sdev->ctrl, SPMI_CMD_EXT_WRITEL, sdev->usid,
270 addr, buf, len);
271}
272EXPORT_SYMBOL_GPL(spmi_ext_register_writel);
273
274/**
275 * spmi_command_reset() - sends RESET command to the specified slave
276 * @sdev: SPMI device.
277 *
278 * The Reset command initializes the Slave and forces all registers to
279 * their reset values. The Slave shall enter the STARTUP state after
280 * receiving a Reset command.
281 */
282int spmi_command_reset(struct spmi_device *sdev)
283{
284 return spmi_cmd(sdev->ctrl, SPMI_CMD_RESET, sdev->usid);
285}
286EXPORT_SYMBOL_GPL(spmi_command_reset);
287
288/**
289 * spmi_command_sleep() - sends SLEEP command to the specified SPMI device
290 * @sdev: SPMI device.
291 *
292 * The Sleep command causes the Slave to enter the user defined SLEEP state.
293 */
294int spmi_command_sleep(struct spmi_device *sdev)
295{
296 return spmi_cmd(sdev->ctrl, SPMI_CMD_SLEEP, sdev->usid);
297}
298EXPORT_SYMBOL_GPL(spmi_command_sleep);
299
300/**
301 * spmi_command_wakeup() - sends WAKEUP command to the specified SPMI device
302 * @sdev: SPMI device.
303 *
304 * The Wakeup command causes the Slave to move from the SLEEP state to
305 * the ACTIVE state.
306 */
307int spmi_command_wakeup(struct spmi_device *sdev)
308{
309 return spmi_cmd(sdev->ctrl, SPMI_CMD_WAKEUP, sdev->usid);
310}
311EXPORT_SYMBOL_GPL(spmi_command_wakeup);
312
313/**
314 * spmi_command_shutdown() - sends SHUTDOWN command to the specified SPMI device
315 * @sdev: SPMI device.
316 *
317 * The Shutdown command causes the Slave to enter the SHUTDOWN state.
318 */
319int spmi_command_shutdown(struct spmi_device *sdev)
320{
321 return spmi_cmd(sdev->ctrl, SPMI_CMD_SHUTDOWN, sdev->usid);
322}
323EXPORT_SYMBOL_GPL(spmi_command_shutdown);
324
325static int spmi_drv_probe(struct device *dev)
326{
327 const struct spmi_driver *sdrv = to_spmi_driver(dev->driver);
328 struct spmi_device *sdev = to_spmi_device(dev);
329 int err;
330
331 pm_runtime_get_noresume(dev);
332 pm_runtime_set_active(dev);
333 pm_runtime_enable(dev);
334
335 err = sdrv->probe(sdev);
336 if (err)
337 goto fail_probe;
338
339 return 0;
340
341fail_probe:
342 pm_runtime_disable(dev);
343 pm_runtime_set_suspended(dev);
344 pm_runtime_put_noidle(dev);
345 return err;
346}
347
348static void spmi_drv_remove(struct device *dev)
349{
350 const struct spmi_driver *sdrv = to_spmi_driver(dev->driver);
351
352 pm_runtime_get_sync(dev);
353 if (sdrv->remove)
354 sdrv->remove(to_spmi_device(dev));
355 pm_runtime_put_noidle(dev);
356
357 pm_runtime_disable(dev);
358 pm_runtime_set_suspended(dev);
359 pm_runtime_put_noidle(dev);
360}
361
362static void spmi_drv_shutdown(struct device *dev)
363{
364 const struct spmi_driver *sdrv = to_spmi_driver(dev->driver);
365
366 if (sdrv && sdrv->shutdown)
367 sdrv->shutdown(to_spmi_device(dev));
368}
369
370static int spmi_drv_uevent(const struct device *dev, struct kobj_uevent_env *env)
371{
372 int ret;
373
374 ret = of_device_uevent_modalias(dev, env);
375 if (ret != -ENODEV)
376 return ret;
377
378 return 0;
379}
380
381static const struct bus_type spmi_bus_type = {
382 .name = "spmi",
383 .match = spmi_device_match,
384 .probe = spmi_drv_probe,
385 .remove = spmi_drv_remove,
386 .shutdown = spmi_drv_shutdown,
387 .uevent = spmi_drv_uevent,
388};
389
390/**
391 * spmi_find_device_by_of_node() - look up an SPMI device from a device node
392 *
393 * @np: device node
394 *
395 * Takes a reference to the embedded struct device which needs to be dropped
396 * after use.
397 *
398 * Returns the struct spmi_device associated with a device node or NULL.
399 */
400struct spmi_device *spmi_find_device_by_of_node(struct device_node *np)
401{
402 struct device *dev = bus_find_device_by_of_node(&spmi_bus_type, np);
403
404 if (dev)
405 return to_spmi_device(dev);
406 return NULL;
407}
408EXPORT_SYMBOL_GPL(spmi_find_device_by_of_node);
409
410/**
411 * spmi_device_alloc() - Allocate a new SPMI device
412 * @ctrl: associated controller
413 *
414 * Caller is responsible for either calling spmi_device_add() to add the
415 * newly allocated controller, or calling spmi_device_put() to discard it.
416 */
417struct spmi_device *spmi_device_alloc(struct spmi_controller *ctrl)
418{
419 struct spmi_device *sdev;
420
421 sdev = kzalloc_obj(*sdev);
422 if (!sdev)
423 return NULL;
424
425 sdev->ctrl = ctrl;
426 device_initialize(&sdev->dev);
427 sdev->dev.parent = &ctrl->dev;
428 sdev->dev.bus = &spmi_bus_type;
429 sdev->dev.type = &spmi_dev_type;
430 return sdev;
431}
432EXPORT_SYMBOL_GPL(spmi_device_alloc);
433
434/**
435 * spmi_controller_alloc() - Allocate a new SPMI controller
436 * @parent: parent device
437 * @size: size of private data
438 *
439 * Caller is responsible for either calling spmi_controller_add() to add the
440 * newly allocated controller, or calling spmi_controller_put() to discard it.
441 * The allocated private data region may be accessed via
442 * spmi_controller_get_drvdata()
443 */
444struct spmi_controller *spmi_controller_alloc(struct device *parent,
445 size_t size)
446{
447 struct spmi_controller *ctrl;
448 int id;
449
450 if (WARN_ON(!parent))
451 return ERR_PTR(-EINVAL);
452
453 ctrl = kzalloc_flex(*ctrl, priv, size);
454 if (!ctrl)
455 return ERR_PTR(-ENOMEM);
456
457 device_initialize(&ctrl->dev);
458 ctrl->dev.type = &spmi_ctrl_type;
459 ctrl->dev.bus = &spmi_bus_type;
460 ctrl->dev.parent = parent;
461 ctrl->dev.of_node = parent->of_node;
462 spmi_controller_set_drvdata(ctrl, ctrl->priv);
463
464 id = ida_alloc(&ctrl_ida, GFP_KERNEL);
465 if (id < 0) {
466 dev_err(parent,
467 "unable to allocate SPMI controller identifier.\n");
468 spmi_controller_put(ctrl);
469 return ERR_PTR(id);
470 }
471
472 ctrl->nr = id;
473 dev_set_name(&ctrl->dev, "spmi-%d", id);
474
475 dev_dbg(&ctrl->dev, "allocated controller 0x%p id %d\n", ctrl, id);
476 return ctrl;
477}
478EXPORT_SYMBOL_GPL(spmi_controller_alloc);
479
480static void of_spmi_register_devices(struct spmi_controller *ctrl)
481{
482 struct device_node *node;
483 int err;
484
485 if (!ctrl->dev.of_node)
486 return;
487
488 for_each_available_child_of_node(ctrl->dev.of_node, node) {
489 struct spmi_device *sdev;
490 u32 reg[2];
491
492 dev_dbg(&ctrl->dev, "adding child %pOF\n", node);
493
494 err = of_property_read_u32_array(node, "reg", reg, 2);
495 if (err) {
496 dev_err(&ctrl->dev,
497 "node %pOF err (%d) does not have 'reg' property\n",
498 node, err);
499 continue;
500 }
501
502 if (reg[1] != SPMI_USID) {
503 dev_err(&ctrl->dev,
504 "node %pOF contains unsupported 'reg' entry\n",
505 node);
506 continue;
507 }
508
509 if (reg[0] >= SPMI_MAX_SLAVE_ID) {
510 dev_err(&ctrl->dev, "invalid usid on node %pOF\n", node);
511 continue;
512 }
513
514 dev_dbg(&ctrl->dev, "read usid %02x\n", reg[0]);
515
516 sdev = spmi_device_alloc(ctrl);
517 if (!sdev)
518 continue;
519
520 device_set_node(&sdev->dev, of_fwnode_handle(node));
521 sdev->usid = (u8)reg[0];
522
523 err = spmi_device_add(sdev);
524 if (err) {
525 dev_err(&sdev->dev,
526 "failure adding device. status %d\n", err);
527 spmi_device_put(sdev);
528 }
529 }
530}
531
532/**
533 * spmi_controller_add() - Add an SPMI controller
534 * @ctrl: controller to be registered.
535 *
536 * Register a controller previously allocated via spmi_controller_alloc() with
537 * the SPMI core.
538 */
539int spmi_controller_add(struct spmi_controller *ctrl)
540{
541 int ret;
542
543 /* Can't register until after driver model init */
544 if (WARN_ON(!is_registered))
545 return -EAGAIN;
546
547 ret = device_add(&ctrl->dev);
548 if (ret)
549 return ret;
550
551 if (IS_ENABLED(CONFIG_OF))
552 of_spmi_register_devices(ctrl);
553
554 dev_dbg(&ctrl->dev, "spmi-%d registered: dev:%p\n",
555 ctrl->nr, &ctrl->dev);
556
557 return 0;
558};
559EXPORT_SYMBOL_GPL(spmi_controller_add);
560
561/* Remove a device associated with a controller */
562static int spmi_ctrl_remove_device(struct device *dev, void *data)
563{
564 struct spmi_device *spmidev = to_spmi_device(dev);
565
566 if (dev->type == &spmi_dev_type)
567 spmi_device_remove(spmidev);
568 return 0;
569}
570
571/**
572 * spmi_controller_remove(): remove an SPMI controller
573 * @ctrl: controller to remove
574 *
575 * Remove a SPMI controller. Caller is responsible for calling
576 * spmi_controller_put() to discard the allocated controller.
577 */
578void spmi_controller_remove(struct spmi_controller *ctrl)
579{
580 if (!ctrl)
581 return;
582
583 device_for_each_child(&ctrl->dev, NULL, spmi_ctrl_remove_device);
584 device_del(&ctrl->dev);
585}
586EXPORT_SYMBOL_GPL(spmi_controller_remove);
587
588/**
589 * __spmi_driver_register() - Register client driver with SPMI core
590 * @sdrv: client driver to be associated with client-device.
591 * @owner: module owner
592 *
593 * This API will register the client driver with the SPMI framework.
594 * It is typically called from the driver's module-init function.
595 */
596int __spmi_driver_register(struct spmi_driver *sdrv, struct module *owner)
597{
598 sdrv->driver.bus = &spmi_bus_type;
599 sdrv->driver.owner = owner;
600 return driver_register(&sdrv->driver);
601}
602EXPORT_SYMBOL_GPL(__spmi_driver_register);
603
604static void __exit spmi_exit(void)
605{
606 bus_unregister(&spmi_bus_type);
607}
608module_exit(spmi_exit);
609
610static int __init spmi_init(void)
611{
612 int ret;
613
614 ret = bus_register(&spmi_bus_type);
615 if (ret)
616 return ret;
617
618 is_registered = true;
619 return 0;
620}
621postcore_initcall(spmi_init);
622
623MODULE_LICENSE("GPL v2");
624MODULE_DESCRIPTION("SPMI module");
625MODULE_ALIAS("platform:spmi");