1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Driver for the Intel SCU IPC mechanism
4 *
5 * (C) Copyright 2008-2010,2015 Intel Corporation
6 * Author: Sreedhara DS (sreedhara.ds@intel.com)
7 *
8 * SCU running in ARC processor communicates with other entity running in IA
9 * core through IPC mechanism which in turn messaging between IA core ad SCU.
10 * SCU has two IPC mechanism IPC-1 and IPC-2. IPC-1 is used between IA32 and
11 * SCU where IPC-2 is used between P-Unit and SCU. This driver delas with
12 * IPC-1 Driver provides an API for power control unit registers (e.g. MSIC)
13 * along with other APIs.
14 */
15
16#include <linux/delay.h>
17#include <linux/device.h>
18#include <linux/errno.h>
19#include <linux/init.h>
20#include <linux/interrupt.h>
21#include <linux/io.h>
22#include <linux/iopoll.h>
23#include <linux/module.h>
24#include <linux/slab.h>
25
26#include <asm/intel_scu_ipc.h>
27
28/* IPC defines the following message types */
29#define IPCMSG_PCNTRL         0xff /* Power controller unit read/write */
30
31/* Command id associated with message IPCMSG_PCNTRL */
32#define IPC_CMD_PCNTRL_W      0 /* Register write */
33#define IPC_CMD_PCNTRL_R      1 /* Register read */
34#define IPC_CMD_PCNTRL_M      2 /* Register read-modify-write */
35
36/*
37 * IPC register summary
38 *
39 * IPC register blocks are memory mapped at fixed address of PCI BAR 0.
40 * To read or write information to the SCU, driver writes to IPC-1 memory
41 * mapped registers. The following is the IPC mechanism
42 *
43 * 1. IA core cDMI interface claims this transaction and converts it to a
44 *    Transaction Layer Packet (TLP) message which is sent across the cDMI.
45 *
46 * 2. South Complex cDMI block receives this message and writes it to
47 *    the IPC-1 register block, causing an interrupt to the SCU
48 *
49 * 3. SCU firmware decodes this interrupt and IPC message and the appropriate
50 *    message handler is called within firmware.
51 */
52
53#define IPC_WWBUF_SIZE    20		/* IPC Write buffer Size */
54#define IPC_RWBUF_SIZE    20		/* IPC Read buffer Size */
55#define IPC_IOC	          0x100		/* IPC command register IOC bit */
56
57struct intel_scu_ipc_dev {
58	struct device dev;
59	struct resource mem;
60	struct module *owner;
61	int irq;
62	void __iomem *ipc_base;
63	struct completion cmd_complete;
64};
65
66#define IPC_STATUS		0x04
67#define IPC_STATUS_IRQ		BIT(2)
68#define IPC_STATUS_ERR		BIT(1)
69#define IPC_STATUS_BUSY		BIT(0)
70
71/*
72 * IPC Write/Read Buffers:
73 * 16 byte buffer for sending and receiving data to and from SCU.
74 */
75#define IPC_WRITE_BUFFER	0x80
76#define IPC_READ_BUFFER		0x90
77
78/* Timeout in jiffies */
79#define IPC_TIMEOUT		(10 * HZ)
80
81static struct intel_scu_ipc_dev *ipcdev; /* Only one for now */
82static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
83
84static struct class intel_scu_ipc_class = {
85	.name = "intel_scu_ipc",
86};
87
88/**
89 * intel_scu_ipc_dev_get() - Get SCU IPC instance
90 *
91 * The recommended new API takes SCU IPC instance as parameter and this
92 * function can be called by driver to get the instance. This also makes
93 * sure the driver providing the IPC functionality cannot be unloaded
94 * while the caller has the instance.
95 *
96 * Call intel_scu_ipc_dev_put() to release the instance.
97 *
98 * Returns %NULL if SCU IPC is not currently available.
99 */
100struct intel_scu_ipc_dev *intel_scu_ipc_dev_get(void)
101{
102	struct intel_scu_ipc_dev *scu = NULL;
103
104	mutex_lock(&ipclock);
105	if (ipcdev) {
106		get_device(&ipcdev->dev);
107		/*
108		 * Prevent the IPC provider from being unloaded while it
109		 * is being used.
110		 */
111		if (!try_module_get(ipcdev->owner))
112			put_device(&ipcdev->dev);
113		else
114			scu = ipcdev;
115	}
116
117	mutex_unlock(&ipclock);
118	return scu;
119}
120EXPORT_SYMBOL_GPL(intel_scu_ipc_dev_get);
121
122/**
123 * intel_scu_ipc_dev_put() - Put SCU IPC instance
124 * @scu: SCU IPC instance
125 *
126 * This function releases the SCU IPC instance retrieved from
127 * intel_scu_ipc_dev_get() and allows the driver providing IPC to be
128 * unloaded.
129 */
130void intel_scu_ipc_dev_put(struct intel_scu_ipc_dev *scu)
131{
132	if (scu) {
133		module_put(scu->owner);
134		put_device(&scu->dev);
135	}
136}
137EXPORT_SYMBOL_GPL(intel_scu_ipc_dev_put);
138
139struct intel_scu_ipc_devres {
140	struct intel_scu_ipc_dev *scu;
141};
142
143static void devm_intel_scu_ipc_dev_release(struct device *dev, void *res)
144{
145	struct intel_scu_ipc_devres *dr = res;
146	struct intel_scu_ipc_dev *scu = dr->scu;
147
148	intel_scu_ipc_dev_put(scu);
149}
150
151/**
152 * devm_intel_scu_ipc_dev_get() - Allocate managed SCU IPC device
153 * @dev: Device requesting the SCU IPC device
154 *
155 * The recommended new API takes SCU IPC instance as parameter and this
156 * function can be called by driver to get the instance. This also makes
157 * sure the driver providing the IPC functionality cannot be unloaded
158 * while the caller has the instance.
159 *
160 * Returns %NULL if SCU IPC is not currently available.
161 */
162struct intel_scu_ipc_dev *devm_intel_scu_ipc_dev_get(struct device *dev)
163{
164	struct intel_scu_ipc_devres *dr;
165	struct intel_scu_ipc_dev *scu;
166
167	dr = devres_alloc(devm_intel_scu_ipc_dev_release, sizeof(*dr), GFP_KERNEL);
168	if (!dr)
169		return NULL;
170
171	scu = intel_scu_ipc_dev_get();
172	if (!scu) {
173		devres_free(dr);
174		return NULL;
175	}
176
177	dr->scu = scu;
178	devres_add(dev, dr);
179
180	return scu;
181}
182EXPORT_SYMBOL_GPL(devm_intel_scu_ipc_dev_get);
183
184/*
185 * Send ipc command
186 * Command Register (Write Only):
187 * A write to this register results in an interrupt to the SCU core processor
188 * Format:
189 * |rfu2(8) | size(8) | command id(4) | rfu1(3) | ioc(1) | command(8)|
190 */
191static inline void ipc_command(struct intel_scu_ipc_dev *scu, u32 cmd)
192{
193	reinit_completion(&scu->cmd_complete);
194	writel(cmd | IPC_IOC, scu->ipc_base);
195}
196
197/*
198 * Write ipc data
199 * IPC Write Buffer (Write Only):
200 * 16-byte buffer for sending data associated with IPC command to
201 * SCU. Size of the data is specified in the IPC_COMMAND_REG register
202 */
203static inline void ipc_data_writel(struct intel_scu_ipc_dev *scu, u32 data, u32 offset)
204{
205	writel(data, scu->ipc_base + IPC_WRITE_BUFFER + offset);
206}
207
208/*
209 * Status Register (Read Only):
210 * Driver will read this register to get the ready/busy status of the IPC
211 * block and error status of the IPC command that was just processed by SCU
212 * Format:
213 * |rfu3(8)|error code(8)|initiator id(8)|cmd id(4)|rfu1(2)|error(1)|busy(1)|
214 */
215static inline u8 ipc_read_status(struct intel_scu_ipc_dev *scu)
216{
217	return __raw_readl(scu->ipc_base + IPC_STATUS);
218}
219
220/* Read ipc byte data */
221static inline u8 ipc_data_readb(struct intel_scu_ipc_dev *scu, u32 offset)
222{
223	return readb(scu->ipc_base + IPC_READ_BUFFER + offset);
224}
225
226/* Read ipc u32 data */
227static inline u32 ipc_data_readl(struct intel_scu_ipc_dev *scu, u32 offset)
228{
229	return readl(scu->ipc_base + IPC_READ_BUFFER + offset);
230}
231
232/* Wait till scu status is busy */
233static inline int busy_loop(struct intel_scu_ipc_dev *scu)
234{
235	u8 status;
236	int err;
237
238	err = readx_poll_timeout(ipc_read_status, scu, status, !(status & IPC_STATUS_BUSY),
239				 100, jiffies_to_usecs(IPC_TIMEOUT));
240	if (err)
241		return err;
242
243	return (status & IPC_STATUS_ERR) ? -EIO : 0;
244}
245
246/* Wait till ipc ioc interrupt is received or timeout in 10 HZ */
247static inline int ipc_wait_for_interrupt(struct intel_scu_ipc_dev *scu)
248{
249	int status;
250
251	wait_for_completion_timeout(&scu->cmd_complete, IPC_TIMEOUT);
252
253	status = ipc_read_status(scu);
254	if (status & IPC_STATUS_BUSY)
255		return -ETIMEDOUT;
256
257	if (status & IPC_STATUS_ERR)
258		return -EIO;
259
260	return 0;
261}
262
263static int intel_scu_ipc_check_status(struct intel_scu_ipc_dev *scu)
264{
265	return scu->irq > 0 ? ipc_wait_for_interrupt(scu) : busy_loop(scu);
266}
267
268static struct intel_scu_ipc_dev *intel_scu_ipc_get(struct intel_scu_ipc_dev *scu)
269{
270	u8 status;
271
272	if (!scu)
273		scu = ipcdev;
274	if (!scu)
275		return ERR_PTR(-ENODEV);
276
277	status = ipc_read_status(scu);
278	if (status & IPC_STATUS_BUSY) {
279		dev_dbg(&scu->dev, "device is busy\n");
280		return ERR_PTR(-EBUSY);
281	}
282
283	return scu;
284}
285
286/* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
287static int pwr_reg_rdwr(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,
288			u32 count, u32 op, u32 id)
289{
290	int nc;
291	u32 offset = 0;
292	int err;
293	u8 cbuf[IPC_WWBUF_SIZE];
294	u32 *wbuf = (u32 *)&cbuf;
295
296	memset(cbuf, 0, sizeof(cbuf));
297
298	mutex_lock(&ipclock);
299	scu = intel_scu_ipc_get(scu);
300	if (IS_ERR(scu)) {
301		mutex_unlock(&ipclock);
302		return PTR_ERR(scu);
303	}
304
305	for (nc = 0; nc < count; nc++, offset += 2) {
306		cbuf[offset] = addr[nc];
307		cbuf[offset + 1] = addr[nc] >> 8;
308	}
309
310	if (id == IPC_CMD_PCNTRL_R) {
311		for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
312			ipc_data_writel(scu, wbuf[nc], offset);
313		ipc_command(scu, (count * 2) << 16 | id << 12 | 0 << 8 | op);
314	} else if (id == IPC_CMD_PCNTRL_W) {
315		for (nc = 0; nc < count; nc++, offset += 1)
316			cbuf[offset] = data[nc];
317		for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
318			ipc_data_writel(scu, wbuf[nc], offset);
319		ipc_command(scu, (count * 3) << 16 | id << 12 | 0 << 8 | op);
320	} else if (id == IPC_CMD_PCNTRL_M) {
321		cbuf[offset] = data[0];
322		cbuf[offset + 1] = data[1];
323		ipc_data_writel(scu, wbuf[0], 0); /* Write wbuff */
324		ipc_command(scu, 4 << 16 | id << 12 | 0 << 8 | op);
325	}
326
327	err = intel_scu_ipc_check_status(scu);
328	if (!err && id == IPC_CMD_PCNTRL_R) { /* Read rbuf */
329		/* Workaround: values are read as 0 without memcpy_fromio */
330		memcpy_fromio(cbuf, scu->ipc_base + 0x90, 16);
331		for (nc = 0; nc < count; nc++)
332			data[nc] = ipc_data_readb(scu, nc);
333	}
334	mutex_unlock(&ipclock);
335	return err;
336}
337
338/**
339 * intel_scu_ipc_dev_ioread8() - Read a byte via the SCU
340 * @scu: Optional SCU IPC instance
341 * @addr: Register on SCU
342 * @data: Return pointer for read byte
343 *
344 * Read a single register. Returns %0 on success or an error code. All
345 * locking between SCU accesses is handled for the caller.
346 *
347 * This function may sleep.
348 */
349int intel_scu_ipc_dev_ioread8(struct intel_scu_ipc_dev *scu, u16 addr, u8 *data)
350{
351	return pwr_reg_rdwr(scu, &addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
352}
353EXPORT_SYMBOL(intel_scu_ipc_dev_ioread8);
354
355/**
356 * intel_scu_ipc_dev_iowrite8() - Write a byte via the SCU
357 * @scu: Optional SCU IPC instance
358 * @addr: Register on SCU
359 * @data: Byte to write
360 *
361 * Write a single register. Returns %0 on success or an error code. All
362 * locking between SCU accesses is handled for the caller.
363 *
364 * This function may sleep.
365 */
366int intel_scu_ipc_dev_iowrite8(struct intel_scu_ipc_dev *scu, u16 addr, u8 data)
367{
368	return pwr_reg_rdwr(scu, &addr, &data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
369}
370EXPORT_SYMBOL(intel_scu_ipc_dev_iowrite8);
371
372/**
373 * intel_scu_ipc_dev_readv() - Read a set of registers
374 * @scu: Optional SCU IPC instance
375 * @addr: Register list
376 * @data: Bytes to return
377 * @len: Length of array
378 *
379 * Read registers. Returns %0 on success or an error code. All locking
380 * between SCU accesses is handled for the caller.
381 *
382 * The largest array length permitted by the hardware is 5 items.
383 *
384 * This function may sleep.
385 */
386int intel_scu_ipc_dev_readv(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,
387			    size_t len)
388{
389	return pwr_reg_rdwr(scu, addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
390}
391EXPORT_SYMBOL(intel_scu_ipc_dev_readv);
392
393/**
394 * intel_scu_ipc_dev_writev() - Write a set of registers
395 * @scu: Optional SCU IPC instance
396 * @addr: Register list
397 * @data: Bytes to write
398 * @len: Length of array
399 *
400 * Write registers. Returns %0 on success or an error code. All locking
401 * between SCU accesses is handled for the caller.
402 *
403 * The largest array length permitted by the hardware is 5 items.
404 *
405 * This function may sleep.
406 */
407int intel_scu_ipc_dev_writev(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,
408			     size_t len)
409{
410	return pwr_reg_rdwr(scu, addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
411}
412EXPORT_SYMBOL(intel_scu_ipc_dev_writev);
413
414/**
415 * intel_scu_ipc_dev_update() - Update a register
416 * @scu: Optional SCU IPC instance
417 * @addr: Register address
418 * @data: Bits to update
419 * @mask: Mask of bits to update
420 *
421 * Read-modify-write power control unit register. The first data argument
422 * must be register value and second is mask value mask is a bitmap that
423 * indicates which bits to update. %0 = masked. Don't modify this bit, %1 =
424 * modify this bit. returns %0 on success or an error code.
425 *
426 * This function may sleep. Locking between SCU accesses is handled
427 * for the caller.
428 */
429int intel_scu_ipc_dev_update(struct intel_scu_ipc_dev *scu, u16 addr, u8 data,
430			     u8 mask)
431{
432	u8 tmp[2] = { data, mask };
433	return pwr_reg_rdwr(scu, &addr, tmp, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_M);
434}
435EXPORT_SYMBOL(intel_scu_ipc_dev_update);
436
437/**
438 * intel_scu_ipc_dev_simple_command() - Send a simple command
439 * @scu: Optional SCU IPC instance
440 * @cmd: Command
441 * @sub: Sub type
442 *
443 * Issue a simple command to the SCU. Do not use this interface if you must
444 * then access data as any data values may be overwritten by another SCU
445 * access by the time this function returns.
446 *
447 * This function may sleep. Locking for SCU accesses is handled for the
448 * caller.
449 */
450int intel_scu_ipc_dev_simple_command(struct intel_scu_ipc_dev *scu, int cmd,
451				     int sub)
452{
453	u32 cmdval;
454	int err;
455
456	mutex_lock(&ipclock);
457	scu = intel_scu_ipc_get(scu);
458	if (IS_ERR(scu)) {
459		mutex_unlock(&ipclock);
460		return PTR_ERR(scu);
461	}
462
463	cmdval = sub << 12 | cmd;
464	ipc_command(scu, cmdval);
465	err = intel_scu_ipc_check_status(scu);
466	mutex_unlock(&ipclock);
467	if (err)
468		dev_err(&scu->dev, "IPC command %#x failed with %d\n", cmdval, err);
469	return err;
470}
471EXPORT_SYMBOL(intel_scu_ipc_dev_simple_command);
472
473/**
474 * intel_scu_ipc_dev_command_with_size() - Command with data
475 * @scu: Optional SCU IPC instance
476 * @cmd: Command
477 * @sub: Sub type
478 * @in: Input data
479 * @inlen: Input length in bytes
480 * @size: Input size written to the IPC command register in whatever
481 *	  units (dword, byte) the particular firmware requires. Normally
482 *	  should be the same as @inlen.
483 * @out: Output data
484 * @outlen: Output length in bytes
485 *
486 * Issue a command to the SCU which involves data transfers. Do the
487 * data copies under the lock but leave it for the caller to interpret.
488 */
489int intel_scu_ipc_dev_command_with_size(struct intel_scu_ipc_dev *scu, int cmd,
490					int sub, const void *in, size_t inlen,
491					size_t size, void *out, size_t outlen)
492{
493	size_t outbuflen = DIV_ROUND_UP(outlen, sizeof(u32));
494	size_t inbuflen = DIV_ROUND_UP(inlen, sizeof(u32));
495	u32 cmdval, inbuf[4] = {};
496	int i, err;
497
498	if (inbuflen > 4 || outbuflen > 4)
499		return -EINVAL;
500
501	mutex_lock(&ipclock);
502	scu = intel_scu_ipc_get(scu);
503	if (IS_ERR(scu)) {
504		mutex_unlock(&ipclock);
505		return PTR_ERR(scu);
506	}
507
508	memcpy(inbuf, in, inlen);
509	for (i = 0; i < inbuflen; i++)
510		ipc_data_writel(scu, inbuf[i], 4 * i);
511
512	cmdval = (size << 16) | (sub << 12) | cmd;
513	ipc_command(scu, cmdval);
514	err = intel_scu_ipc_check_status(scu);
515
516	if (!err) {
517		u32 outbuf[4] = {};
518
519		for (i = 0; i < outbuflen; i++)
520			outbuf[i] = ipc_data_readl(scu, 4 * i);
521
522		memcpy(out, outbuf, outlen);
523	}
524
525	mutex_unlock(&ipclock);
526	if (err)
527		dev_err(&scu->dev, "IPC command %#x failed with %d\n", cmdval, err);
528	return err;
529}
530EXPORT_SYMBOL(intel_scu_ipc_dev_command_with_size);
531
532/*
533 * Interrupt handler gets called when ioc bit of IPC_COMMAND_REG set to 1
534 * When ioc bit is set to 1, caller api must wait for interrupt handler called
535 * which in turn unlocks the caller api. Currently this is not used
536 *
537 * This is edge triggered so we need take no action to clear anything
538 */
539static irqreturn_t ioc(int irq, void *dev_id)
540{
541	struct intel_scu_ipc_dev *scu = dev_id;
542	int status = ipc_read_status(scu);
543
544	writel(status | IPC_STATUS_IRQ, scu->ipc_base + IPC_STATUS);
545	complete(&scu->cmd_complete);
546
547	return IRQ_HANDLED;
548}
549
550static void intel_scu_ipc_release(struct device *dev)
551{
552	struct intel_scu_ipc_dev *scu;
553
554	scu = container_of(dev, struct intel_scu_ipc_dev, dev);
555	if (scu->irq > 0)
556		free_irq(scu->irq, scu);
557	iounmap(scu->ipc_base);
558	release_mem_region(scu->mem.start, resource_size(&scu->mem));
559	kfree(scu);
560}
561
562/**
563 * __intel_scu_ipc_register() - Register SCU IPC device
564 * @parent: Parent device
565 * @scu_data: Data used to configure SCU IPC
566 * @owner: Module registering the SCU IPC device
567 *
568 * Call this function to register SCU IPC mechanism under @parent.
569 * Returns pointer to the new SCU IPC device or ERR_PTR() in case of
570 * failure. The caller may use the returned instance if it needs to do
571 * SCU IPC calls itself.
572 */
573struct intel_scu_ipc_dev *
574__intel_scu_ipc_register(struct device *parent,
575			 const struct intel_scu_ipc_data *scu_data,
576			 struct module *owner)
577{
578	int err;
579	struct intel_scu_ipc_dev *scu;
580	void __iomem *ipc_base;
581
582	mutex_lock(&ipclock);
583	/* We support only one IPC */
584	if (ipcdev) {
585		err = -EBUSY;
586		goto err_unlock;
587	}
588
589	scu = kzalloc(sizeof(*scu), GFP_KERNEL);
590	if (!scu) {
591		err = -ENOMEM;
592		goto err_unlock;
593	}
594
595	scu->owner = owner;
596	scu->dev.parent = parent;
597	scu->dev.class = &intel_scu_ipc_class;
598	scu->dev.release = intel_scu_ipc_release;
599
600	if (!request_mem_region(scu_data->mem.start, resource_size(&scu_data->mem),
601				"intel_scu_ipc")) {
602		err = -EBUSY;
603		goto err_free;
604	}
605
606	ipc_base = ioremap(scu_data->mem.start, resource_size(&scu_data->mem));
607	if (!ipc_base) {
608		err = -ENOMEM;
609		goto err_release;
610	}
611
612	scu->ipc_base = ipc_base;
613	scu->mem = scu_data->mem;
614	scu->irq = scu_data->irq;
615	init_completion(&scu->cmd_complete);
616
617	if (scu->irq > 0) {
618		err = request_irq(scu->irq, ioc, 0, "intel_scu_ipc", scu);
619		if (err)
620			goto err_unmap;
621	}
622
623	/*
624	 * After this point intel_scu_ipc_release() takes care of
625	 * releasing the SCU IPC resources once refcount drops to zero.
626	 */
627	dev_set_name(&scu->dev, "intel_scu_ipc");
628	err = device_register(&scu->dev);
629	if (err) {
630		put_device(&scu->dev);
631		goto err_unlock;
632	}
633
634	/* Assign device at last */
635	ipcdev = scu;
636	mutex_unlock(&ipclock);
637
638	return scu;
639
640err_unmap:
641	iounmap(ipc_base);
642err_release:
643	release_mem_region(scu_data->mem.start, resource_size(&scu_data->mem));
644err_free:
645	kfree(scu);
646err_unlock:
647	mutex_unlock(&ipclock);
648
649	return ERR_PTR(err);
650}
651EXPORT_SYMBOL_GPL(__intel_scu_ipc_register);
652
653/**
654 * intel_scu_ipc_unregister() - Unregister SCU IPC
655 * @scu: SCU IPC handle
656 *
657 * This unregisters the SCU IPC device and releases the acquired
658 * resources once the refcount goes to zero.
659 */
660void intel_scu_ipc_unregister(struct intel_scu_ipc_dev *scu)
661{
662	mutex_lock(&ipclock);
663	if (!WARN_ON(!ipcdev)) {
664		ipcdev = NULL;
665		device_unregister(&scu->dev);
666	}
667	mutex_unlock(&ipclock);
668}
669EXPORT_SYMBOL_GPL(intel_scu_ipc_unregister);
670
671static void devm_intel_scu_ipc_unregister(struct device *dev, void *res)
672{
673	struct intel_scu_ipc_devres *dr = res;
674	struct intel_scu_ipc_dev *scu = dr->scu;
675
676	intel_scu_ipc_unregister(scu);
677}
678
679/**
680 * __devm_intel_scu_ipc_register() - Register managed SCU IPC device
681 * @parent: Parent device
682 * @scu_data: Data used to configure SCU IPC
683 * @owner: Module registering the SCU IPC device
684 *
685 * Call this function to register managed SCU IPC mechanism under
686 * @parent. Returns pointer to the new SCU IPC device or ERR_PTR() in
687 * case of failure. The caller may use the returned instance if it needs
688 * to do SCU IPC calls itself.
689 */
690struct intel_scu_ipc_dev *
691__devm_intel_scu_ipc_register(struct device *parent,
692			      const struct intel_scu_ipc_data *scu_data,
693			      struct module *owner)
694{
695	struct intel_scu_ipc_devres *dr;
696	struct intel_scu_ipc_dev *scu;
697
698	dr = devres_alloc(devm_intel_scu_ipc_unregister, sizeof(*dr), GFP_KERNEL);
699	if (!dr)
700		return NULL;
701
702	scu = __intel_scu_ipc_register(parent, scu_data, owner);
703	if (IS_ERR(scu)) {
704		devres_free(dr);
705		return scu;
706	}
707
708	dr->scu = scu;
709	devres_add(parent, dr);
710
711	return scu;
712}
713EXPORT_SYMBOL_GPL(__devm_intel_scu_ipc_register);
714
715static int __init intel_scu_ipc_init(void)
716{
717	return class_register(&intel_scu_ipc_class);
718}
719subsys_initcall(intel_scu_ipc_init);
720
721static void __exit intel_scu_ipc_exit(void)
722{
723	class_unregister(&intel_scu_ipc_class);
724}
725module_exit(intel_scu_ipc_exit);
726