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v6.2
  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/module.h>
 23#include <linux/slab.h>
 24
 
 25#include <asm/intel_scu_ipc.h>
 26
 27/* IPC defines the following message types */
 28#define IPCMSG_PCNTRL         0xff /* Power controller unit read/write */
 
 
 
 
 29
 30/* Command id associated with message IPCMSG_PCNTRL */
 31#define IPC_CMD_PCNTRL_W      0 /* Register write */
 32#define IPC_CMD_PCNTRL_R      1 /* Register read */
 33#define IPC_CMD_PCNTRL_M      2 /* Register read-modify-write */
 34
 35/*
 36 * IPC register summary
 37 *
 38 * IPC register blocks are memory mapped at fixed address of PCI BAR 0.
 39 * To read or write information to the SCU, driver writes to IPC-1 memory
 40 * mapped registers. The following is the IPC mechanism
 41 *
 42 * 1. IA core cDMI interface claims this transaction and converts it to a
 43 *    Transaction Layer Packet (TLP) message which is sent across the cDMI.
 44 *
 45 * 2. South Complex cDMI block receives this message and writes it to
 46 *    the IPC-1 register block, causing an interrupt to the SCU
 47 *
 48 * 3. SCU firmware decodes this interrupt and IPC message and the appropriate
 49 *    message handler is called within firmware.
 50 */
 51
 52#define IPC_WWBUF_SIZE    20		/* IPC Write buffer Size */
 53#define IPC_RWBUF_SIZE    20		/* IPC Read buffer Size */
 54#define IPC_IOC	          0x100		/* IPC command register IOC bit */
 55
 56struct intel_scu_ipc_dev {
 57	struct device dev;
 58	struct resource mem;
 59	struct module *owner;
 60	int irq;
 61	void __iomem *ipc_base;
 62	struct completion cmd_complete;
 
 
 
 63};
 64
 65#define IPC_STATUS		0x04
 66#define IPC_STATUS_IRQ		BIT(2)
 67#define IPC_STATUS_ERR		BIT(1)
 68#define IPC_STATUS_BUSY		BIT(0)
 69
 70/*
 71 * IPC Write/Read Buffers:
 72 * 16 byte buffer for sending and receiving data to and from SCU.
 73 */
 74#define IPC_WRITE_BUFFER	0x80
 75#define IPC_READ_BUFFER		0x90
 76
 77/* Timeout in jiffies */
 78#define IPC_TIMEOUT		(10 * HZ)
 79
 80static struct intel_scu_ipc_dev *ipcdev; /* Only one for now */
 81static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
 82
 83static struct class intel_scu_ipc_class = {
 84	.name = "intel_scu_ipc",
 85	.owner = THIS_MODULE,
 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	unsigned long end = jiffies + IPC_TIMEOUT;
236
237	do {
238		u32 status;
239
 
 
 
240		status = ipc_read_status(scu);
241		if (!(status & IPC_STATUS_BUSY))
242			return (status & IPC_STATUS_ERR) ? -EIO : 0;
 
 
 
 
243
244		usleep_range(50, 100);
245	} while (time_before(jiffies, end));
246
247	return -ETIMEDOUT;
248}
249
250/* Wait till ipc ioc interrupt is received or timeout in 10 HZ */
251static inline int ipc_wait_for_interrupt(struct intel_scu_ipc_dev *scu)
252{
253	int status;
254
255	if (!wait_for_completion_timeout(&scu->cmd_complete, IPC_TIMEOUT))
 
256		return -ETIMEDOUT;
 
257
258	status = ipc_read_status(scu);
259	if (status & IPC_STATUS_ERR)
260		return -EIO;
261
262	return 0;
263}
264
265static int intel_scu_ipc_check_status(struct intel_scu_ipc_dev *scu)
266{
267	return scu->irq > 0 ? ipc_wait_for_interrupt(scu) : busy_loop(scu);
268}
269
270/* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
271static int pwr_reg_rdwr(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,
272			u32 count, u32 op, u32 id)
273{
 
274	int nc;
275	u32 offset = 0;
276	int err;
277	u8 cbuf[IPC_WWBUF_SIZE];
278	u32 *wbuf = (u32 *)&cbuf;
279
280	memset(cbuf, 0, sizeof(cbuf));
281
282	mutex_lock(&ipclock);
283	if (!scu)
284		scu = ipcdev;
285	if (!scu) {
286		mutex_unlock(&ipclock);
287		return -ENODEV;
288	}
289
290	for (nc = 0; nc < count; nc++, offset += 2) {
291		cbuf[offset] = addr[nc];
292		cbuf[offset + 1] = addr[nc] >> 8;
293	}
294
295	if (id == IPC_CMD_PCNTRL_R) {
296		for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
297			ipc_data_writel(scu, wbuf[nc], offset);
298		ipc_command(scu, (count * 2) << 16 | id << 12 | 0 << 8 | op);
299	} else if (id == IPC_CMD_PCNTRL_W) {
300		for (nc = 0; nc < count; nc++, offset += 1)
301			cbuf[offset] = data[nc];
302		for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
303			ipc_data_writel(scu, wbuf[nc], offset);
304		ipc_command(scu, (count * 3) << 16 | id << 12 | 0 << 8 | op);
305	} else if (id == IPC_CMD_PCNTRL_M) {
306		cbuf[offset] = data[0];
307		cbuf[offset + 1] = data[1];
308		ipc_data_writel(scu, wbuf[0], 0); /* Write wbuff */
309		ipc_command(scu, 4 << 16 | id << 12 | 0 << 8 | op);
310	}
311
312	err = intel_scu_ipc_check_status(scu);
313	if (!err && id == IPC_CMD_PCNTRL_R) { /* Read rbuf */
314		/* Workaround: values are read as 0 without memcpy_fromio */
315		memcpy_fromio(cbuf, scu->ipc_base + 0x90, 16);
316		for (nc = 0; nc < count; nc++)
317			data[nc] = ipc_data_readb(scu, nc);
318	}
319	mutex_unlock(&ipclock);
320	return err;
321}
322
323/**
324 * intel_scu_ipc_dev_ioread8() - Read a byte via the SCU
325 * @scu: Optional SCU IPC instance
326 * @addr: Register on SCU
327 * @data: Return pointer for read byte
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
328 *
329 * Read a single register. Returns %0 on success or an error code. All
330 * locking between SCU accesses is handled for the caller.
331 *
332 * This function may sleep.
333 */
334int intel_scu_ipc_dev_ioread8(struct intel_scu_ipc_dev *scu, u16 addr, u8 *data)
335{
336	return pwr_reg_rdwr(scu, &addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
 
337}
338EXPORT_SYMBOL(intel_scu_ipc_dev_ioread8);
339
340/**
341 * intel_scu_ipc_dev_iowrite8() - Write a byte via the SCU
342 * @scu: Optional SCU IPC instance
343 * @addr: Register on SCU
344 * @data: Byte to write
345 *
346 * Write a single register. Returns %0 on success or an error code. All
347 * locking between SCU accesses is handled for the caller.
348 *
349 * This function may sleep.
350 */
351int intel_scu_ipc_dev_iowrite8(struct intel_scu_ipc_dev *scu, u16 addr, u8 data)
352{
353	return pwr_reg_rdwr(scu, &addr, &data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
354}
355EXPORT_SYMBOL(intel_scu_ipc_dev_iowrite8);
356
357/**
358 * intel_scu_ipc_dev_readv() - Read a set of registers
359 * @scu: Optional SCU IPC instance
360 * @addr: Register list
361 * @data: Bytes to return
362 * @len: Length of array
363 *
364 * Read registers. Returns %0 on success or an error code. All locking
365 * between SCU accesses is handled for the caller.
366 *
367 * The largest array length permitted by the hardware is 5 items.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
368 *
369 * This function may sleep.
 
 
 
 
 
370 */
371int intel_scu_ipc_dev_readv(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,
372			    size_t len)
373{
374	return pwr_reg_rdwr(scu, addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
375}
376EXPORT_SYMBOL(intel_scu_ipc_dev_readv);
377
378/**
379 * intel_scu_ipc_dev_writev() - Write a set of registers
380 * @scu: Optional SCU IPC instance
381 * @addr: Register list
382 * @data: Bytes to write
383 * @len: Length of array
 
 
384 *
385 * Write registers. Returns %0 on success or an error code. All locking
386 * between SCU accesses is handled for the caller.
387 *
388 * The largest array length permitted by the hardware is 5 items.
389 *
390 * This function may sleep.
391 */
392int intel_scu_ipc_dev_writev(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,
393			     size_t len)
394{
395	return pwr_reg_rdwr(scu, addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
396}
397EXPORT_SYMBOL(intel_scu_ipc_dev_writev);
398
399/**
400 * intel_scu_ipc_dev_update() - Update a register
401 * @scu: Optional SCU IPC instance
402 * @addr: Register address
403 * @data: Bits to update
404 * @mask: Mask of bits to update
405 *
406 * Read-modify-write power control unit register. The first data argument
407 * must be register value and second is mask value mask is a bitmap that
408 * indicates which bits to update. %0 = masked. Don't modify this bit, %1 =
409 * modify this bit. returns %0 on success or an error code.
 
410 *
411 * This function may sleep. Locking between SCU accesses is handled
412 * for the caller.
413 */
414int intel_scu_ipc_dev_update(struct intel_scu_ipc_dev *scu, u16 addr, u8 data,
415			     u8 mask)
416{
417	u8 tmp[2] = { data, mask };
418	return pwr_reg_rdwr(scu, &addr, tmp, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_M);
419}
420EXPORT_SYMBOL(intel_scu_ipc_dev_update);
421
422/**
423 * intel_scu_ipc_dev_simple_command() - Send a simple command
424 * @scu: Optional SCU IPC instance
425 * @cmd: Command
426 * @sub: Sub type
427 *
428 * Issue a simple command to the SCU. Do not use this interface if you must
429 * then access data as any data values may be overwritten by another SCU
430 * access by the time this function returns.
431 *
432 * This function may sleep. Locking for SCU accesses is handled for the
433 * caller.
434 */
435int intel_scu_ipc_dev_simple_command(struct intel_scu_ipc_dev *scu, int cmd,
436				     int sub)
437{
438	u32 cmdval;
439	int err;
440
441	mutex_lock(&ipclock);
442	if (!scu)
443		scu = ipcdev;
444	if (!scu) {
445		mutex_unlock(&ipclock);
446		return -ENODEV;
447	}
448	scu = ipcdev;
449	cmdval = sub << 12 | cmd;
450	ipc_command(scu, cmdval);
451	err = intel_scu_ipc_check_status(scu);
452	mutex_unlock(&ipclock);
453	if (err)
454		dev_err(&scu->dev, "IPC command %#x failed with %d\n", cmdval, err);
455	return err;
456}
457EXPORT_SYMBOL(intel_scu_ipc_dev_simple_command);
458
459/**
460 * intel_scu_ipc_dev_command_with_size() - Command with data
461 * @scu: Optional SCU IPC instance
462 * @cmd: Command
463 * @sub: Sub type
464 * @in: Input data
465 * @inlen: Input length in bytes
466 * @size: Input size written to the IPC command register in whatever
467 *	  units (dword, byte) the particular firmware requires. Normally
468 *	  should be the same as @inlen.
469 * @out: Output data
470 * @outlen: Output length in bytes
471 *
472 * Issue a command to the SCU which involves data transfers. Do the
473 * data copies under the lock but leave it for the caller to interpret.
474 */
475int intel_scu_ipc_dev_command_with_size(struct intel_scu_ipc_dev *scu, int cmd,
476					int sub, const void *in, size_t inlen,
477					size_t size, void *out, size_t outlen)
478{
479	size_t outbuflen = DIV_ROUND_UP(outlen, sizeof(u32));
480	size_t inbuflen = DIV_ROUND_UP(inlen, sizeof(u32));
481	u32 cmdval, inbuf[4] = {};
482	int i, err;
483
484	if (inbuflen > 4 || outbuflen > 4)
485		return -EINVAL;
486
487	mutex_lock(&ipclock);
488	if (!scu)
489		scu = ipcdev;
490	if (!scu) {
491		mutex_unlock(&ipclock);
492		return -ENODEV;
493	}
494
495	memcpy(inbuf, in, inlen);
496	for (i = 0; i < inbuflen; i++)
497		ipc_data_writel(scu, inbuf[i], 4 * i);
498
499	cmdval = (size << 16) | (sub << 12) | cmd;
500	ipc_command(scu, cmdval);
501	err = intel_scu_ipc_check_status(scu);
502
503	if (!err) {
504		u32 outbuf[4] = {};
505
506		for (i = 0; i < outbuflen; i++)
507			outbuf[i] = ipc_data_readl(scu, 4 * i);
508
509		memcpy(out, outbuf, outlen);
510	}
511
512	mutex_unlock(&ipclock);
513	if (err)
514		dev_err(&scu->dev, "IPC command %#x failed with %d\n", cmdval, err);
515	return err;
516}
517EXPORT_SYMBOL(intel_scu_ipc_dev_command_with_size);
518
519/*
520 * Interrupt handler gets called when ioc bit of IPC_COMMAND_REG set to 1
521 * When ioc bit is set to 1, caller api must wait for interrupt handler called
522 * which in turn unlocks the caller api. Currently this is not used
523 *
524 * This is edge triggered so we need take no action to clear anything
525 */
526static irqreturn_t ioc(int irq, void *dev_id)
527{
528	struct intel_scu_ipc_dev *scu = dev_id;
529	int status = ipc_read_status(scu);
530
531	writel(status | IPC_STATUS_IRQ, scu->ipc_base + IPC_STATUS);
532	complete(&scu->cmd_complete);
533
534	return IRQ_HANDLED;
535}
536
537static void intel_scu_ipc_release(struct device *dev)
538{
539	struct intel_scu_ipc_dev *scu;
540
541	scu = container_of(dev, struct intel_scu_ipc_dev, dev);
542	if (scu->irq > 0)
543		free_irq(scu->irq, scu);
544	iounmap(scu->ipc_base);
545	release_mem_region(scu->mem.start, resource_size(&scu->mem));
546	kfree(scu);
547}
548
549/**
550 * __intel_scu_ipc_register() - Register SCU IPC device
551 * @parent: Parent device
552 * @scu_data: Data used to configure SCU IPC
553 * @owner: Module registering the SCU IPC device
 
 
 
 
 
 
 
554 *
555 * Call this function to register SCU IPC mechanism under @parent.
556 * Returns pointer to the new SCU IPC device or ERR_PTR() in case of
557 * failure. The caller may use the returned instance if it needs to do
558 * SCU IPC calls itself.
559 */
560struct intel_scu_ipc_dev *
561__intel_scu_ipc_register(struct device *parent,
562			 const struct intel_scu_ipc_data *scu_data,
563			 struct module *owner)
564{
565	int err;
566	struct intel_scu_ipc_dev *scu;
567	void __iomem *ipc_base;
568
569	mutex_lock(&ipclock);
570	/* We support only one IPC */
571	if (ipcdev) {
572		err = -EBUSY;
573		goto err_unlock;
574	}
575
576	scu = kzalloc(sizeof(*scu), GFP_KERNEL);
577	if (!scu) {
578		err = -ENOMEM;
579		goto err_unlock;
580	}
581
582	scu->owner = owner;
583	scu->dev.parent = parent;
584	scu->dev.class = &intel_scu_ipc_class;
585	scu->dev.release = intel_scu_ipc_release;
586
587	if (!request_mem_region(scu_data->mem.start, resource_size(&scu_data->mem),
588				"intel_scu_ipc")) {
589		err = -EBUSY;
590		goto err_free;
591	}
592
593	ipc_base = ioremap(scu_data->mem.start, resource_size(&scu_data->mem));
594	if (!ipc_base) {
595		err = -ENOMEM;
596		goto err_release;
597	}
598
599	scu->ipc_base = ipc_base;
600	scu->mem = scu_data->mem;
601	scu->irq = scu_data->irq;
602	init_completion(&scu->cmd_complete);
603
604	if (scu->irq > 0) {
605		err = request_irq(scu->irq, ioc, 0, "intel_scu_ipc", scu);
606		if (err)
607			goto err_unmap;
608	}
609
610	/*
611	 * After this point intel_scu_ipc_release() takes care of
612	 * releasing the SCU IPC resources once refcount drops to zero.
 
 
 
613	 */
614	dev_set_name(&scu->dev, "intel_scu_ipc");
615	err = device_register(&scu->dev);
616	if (err) {
617		put_device(&scu->dev);
618		goto err_unlock;
619	}
620
621	/* Assign device at last */
622	ipcdev = scu;
623	mutex_unlock(&ipclock);
624
625	return scu;
 
 
 
 
 
626
627err_unmap:
628	iounmap(ipc_base);
629err_release:
630	release_mem_region(scu_data->mem.start, resource_size(&scu_data->mem));
631err_free:
632	kfree(scu);
633err_unlock:
634	mutex_unlock(&ipclock);
635
636	return ERR_PTR(err);
637}
638EXPORT_SYMBOL_GPL(__intel_scu_ipc_register);
 
 
 
 
639
640/**
641 * intel_scu_ipc_unregister() - Unregister SCU IPC
642 * @scu: SCU IPC handle
 
 
 
 
643 *
644 * This unregisters the SCU IPC device and releases the acquired
645 * resources once the refcount goes to zero.
 
646 */
647void intel_scu_ipc_unregister(struct intel_scu_ipc_dev *scu)
648{
 
 
 
649	mutex_lock(&ipclock);
650	if (!WARN_ON(!ipcdev)) {
651		ipcdev = NULL;
652		device_unregister(&scu->dev);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
653	}
654	mutex_unlock(&ipclock);
 
655}
656EXPORT_SYMBOL_GPL(intel_scu_ipc_unregister);
657
658static void devm_intel_scu_ipc_unregister(struct device *dev, void *res)
 
 
 
 
 
 
 
659{
660	struct intel_scu_ipc_devres *dr = res;
661	struct intel_scu_ipc_dev *scu = dr->scu;
662
663	intel_scu_ipc_unregister(scu);
 
 
 
664}
665
666/**
667 * __devm_intel_scu_ipc_register() - Register managed SCU IPC device
668 * @parent: Parent device
669 * @scu_data: Data used to configure SCU IPC
670 * @owner: Module registering the SCU IPC device
671 *
672 * Call this function to register managed SCU IPC mechanism under
673 * @parent. Returns pointer to the new SCU IPC device or ERR_PTR() in
674 * case of failure. The caller may use the returned instance if it needs
675 * to do SCU IPC calls itself.
676 */
677struct intel_scu_ipc_dev *
678__devm_intel_scu_ipc_register(struct device *parent,
679			      const struct intel_scu_ipc_data *scu_data,
680			      struct module *owner)
681{
682	struct intel_scu_ipc_devres *dr;
683	struct intel_scu_ipc_dev *scu;
 
684
685	dr = devres_alloc(devm_intel_scu_ipc_unregister, sizeof(*dr), GFP_KERNEL);
686	if (!dr)
687		return NULL;
688
689	scu = __intel_scu_ipc_register(parent, scu_data, owner);
690	if (IS_ERR(scu)) {
691		devres_free(dr);
692		return scu;
693	}
694
695	dr->scu = scu;
696	devres_add(parent, dr);
697
698	return scu;
699}
700EXPORT_SYMBOL_GPL(__devm_intel_scu_ipc_register);
701
702static int __init intel_scu_ipc_init(void)
703{
704	return class_register(&intel_scu_ipc_class);
705}
706subsys_initcall(intel_scu_ipc_init);
707
708static void __exit intel_scu_ipc_exit(void)
709{
710	class_unregister(&intel_scu_ipc_class);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
711}
712module_exit(intel_scu_ipc_exit);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
v5.4
  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/pci.h>
 22#include <linux/pm.h>
 23#include <linux/sfi.h>
 24
 25#include <asm/intel-mid.h>
 26#include <asm/intel_scu_ipc.h>
 27
 28/* IPC defines the following message types */
 29#define IPCMSG_WATCHDOG_TIMER 0xF8 /* Set Kernel Watchdog Threshold */
 30#define IPCMSG_BATTERY        0xEF /* Coulomb Counter Accumulator */
 31#define IPCMSG_FW_UPDATE      0xFE /* Firmware update */
 32#define IPCMSG_PCNTRL         0xFF /* Power controller unit read/write */
 33#define IPCMSG_FW_REVISION    0xF4 /* Get firmware revision */
 34
 35/* Command id associated with message IPCMSG_PCNTRL */
 36#define IPC_CMD_PCNTRL_W      0 /* Register write */
 37#define IPC_CMD_PCNTRL_R      1 /* Register read */
 38#define IPC_CMD_PCNTRL_M      2 /* Register read-modify-write */
 39
 40/*
 41 * IPC register summary
 42 *
 43 * IPC register blocks are memory mapped at fixed address of PCI BAR 0.
 44 * To read or write information to the SCU, driver writes to IPC-1 memory
 45 * mapped registers. The following is the IPC mechanism
 46 *
 47 * 1. IA core cDMI interface claims this transaction and converts it to a
 48 *    Transaction Layer Packet (TLP) message which is sent across the cDMI.
 49 *
 50 * 2. South Complex cDMI block receives this message and writes it to
 51 *    the IPC-1 register block, causing an interrupt to the SCU
 52 *
 53 * 3. SCU firmware decodes this interrupt and IPC message and the appropriate
 54 *    message handler is called within firmware.
 55 */
 56
 57#define IPC_WWBUF_SIZE    20		/* IPC Write buffer Size */
 58#define IPC_RWBUF_SIZE    20		/* IPC Read buffer Size */
 59#define IPC_IOC	          0x100		/* IPC command register IOC bit */
 60
 61#define PCI_DEVICE_ID_LINCROFT		0x082a
 62#define PCI_DEVICE_ID_PENWELL		0x080e
 63#define PCI_DEVICE_ID_CLOVERVIEW	0x08ea
 64#define PCI_DEVICE_ID_TANGIER		0x11a0
 65
 66/* intel scu ipc driver data */
 67struct intel_scu_ipc_pdata_t {
 68	u32 i2c_base;
 69	u32 i2c_len;
 70	u8 irq_mode;
 71};
 72
 73static const struct intel_scu_ipc_pdata_t intel_scu_ipc_lincroft_pdata = {
 74	.i2c_base = 0xff12b000,
 75	.i2c_len = 0x10,
 76	.irq_mode = 0,
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 77};
 78
 79/* Penwell and Cloverview */
 80static const struct intel_scu_ipc_pdata_t intel_scu_ipc_penwell_pdata = {
 81	.i2c_base = 0xff12b000,
 82	.i2c_len = 0x10,
 83	.irq_mode = 1,
 84};
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 85
 86static const struct intel_scu_ipc_pdata_t intel_scu_ipc_tangier_pdata = {
 87	.i2c_base  = 0xff00d000,
 88	.i2c_len = 0x10,
 89	.irq_mode = 0,
 90};
 91
 92struct intel_scu_ipc_dev {
 93	struct device *dev;
 94	void __iomem *ipc_base;
 95	void __iomem *i2c_base;
 96	struct completion cmd_complete;
 97	u8 irq_mode;
 98};
 99
100static struct intel_scu_ipc_dev  ipcdev; /* Only one for now */
 
101
102/*
103 * IPC Read Buffer (Read Only):
104 * 16 byte buffer for receiving data from SCU, if IPC command
105 * processing results in response data
 
 
 
 
 
 
106 */
107#define IPC_READ_BUFFER		0x90
 
 
 
 
 
 
 
 
 
 
 
 
 
108
109#define IPC_I2C_CNTRL_ADDR	0
110#define I2C_DATA_ADDR		0x04
111
112static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
 
 
113
114/*
115 * Send ipc command
116 * Command Register (Write Only):
117 * A write to this register results in an interrupt to the SCU core processor
118 * Format:
119 * |rfu2(8) | size(8) | command id(4) | rfu1(3) | ioc(1) | command(8)|
120 */
121static inline void ipc_command(struct intel_scu_ipc_dev *scu, u32 cmd)
122{
123	if (scu->irq_mode) {
124		reinit_completion(&scu->cmd_complete);
125		writel(cmd | IPC_IOC, scu->ipc_base);
126	}
127	writel(cmd, scu->ipc_base);
128}
129
130/*
131 * Write ipc data
132 * IPC Write Buffer (Write Only):
133 * 16-byte buffer for sending data associated with IPC command to
134 * SCU. Size of the data is specified in the IPC_COMMAND_REG register
135 */
136static inline void ipc_data_writel(struct intel_scu_ipc_dev *scu, u32 data, u32 offset)
137{
138	writel(data, scu->ipc_base + 0x80 + offset);
139}
140
141/*
142 * Status Register (Read Only):
143 * Driver will read this register to get the ready/busy status of the IPC
144 * block and error status of the IPC command that was just processed by SCU
145 * Format:
146 * |rfu3(8)|error code(8)|initiator id(8)|cmd id(4)|rfu1(2)|error(1)|busy(1)|
147 */
148static inline u8 ipc_read_status(struct intel_scu_ipc_dev *scu)
149{
150	return __raw_readl(scu->ipc_base + 0x04);
151}
152
153/* Read ipc byte data */
154static inline u8 ipc_data_readb(struct intel_scu_ipc_dev *scu, u32 offset)
155{
156	return readb(scu->ipc_base + IPC_READ_BUFFER + offset);
157}
158
159/* Read ipc u32 data */
160static inline u32 ipc_data_readl(struct intel_scu_ipc_dev *scu, u32 offset)
161{
162	return readl(scu->ipc_base + IPC_READ_BUFFER + offset);
163}
164
165/* Wait till scu status is busy */
166static inline int busy_loop(struct intel_scu_ipc_dev *scu)
167{
168	u32 status = ipc_read_status(scu);
169	u32 loop_count = 100000;
 
 
170
171	/* break if scu doesn't reset busy bit after huge retry */
172	while ((status & BIT(0)) && --loop_count) {
173		udelay(1); /* scu processing time is in few u secods */
174		status = ipc_read_status(scu);
175	}
176
177	if (status & BIT(0)) {
178		dev_err(scu->dev, "IPC timed out");
179		return -ETIMEDOUT;
180	}
181
182	if (status & BIT(1))
183		return -EIO;
184
185	return 0;
186}
187
188/* Wait till ipc ioc interrupt is received or timeout in 3 HZ */
189static inline int ipc_wait_for_interrupt(struct intel_scu_ipc_dev *scu)
190{
191	int status;
192
193	if (!wait_for_completion_timeout(&scu->cmd_complete, 3 * HZ)) {
194		dev_err(scu->dev, "IPC timed out\n");
195		return -ETIMEDOUT;
196	}
197
198	status = ipc_read_status(scu);
199	if (status & BIT(1))
200		return -EIO;
201
202	return 0;
203}
204
205static int intel_scu_ipc_check_status(struct intel_scu_ipc_dev *scu)
206{
207	return scu->irq_mode ? ipc_wait_for_interrupt(scu) : busy_loop(scu);
208}
209
210/* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
211static int pwr_reg_rdwr(u16 *addr, u8 *data, u32 count, u32 op, u32 id)
 
212{
213	struct intel_scu_ipc_dev *scu = &ipcdev;
214	int nc;
215	u32 offset = 0;
216	int err;
217	u8 cbuf[IPC_WWBUF_SIZE];
218	u32 *wbuf = (u32 *)&cbuf;
219
220	memset(cbuf, 0, sizeof(cbuf));
221
222	mutex_lock(&ipclock);
223
224	if (scu->dev == NULL) {
 
225		mutex_unlock(&ipclock);
226		return -ENODEV;
227	}
228
229	for (nc = 0; nc < count; nc++, offset += 2) {
230		cbuf[offset] = addr[nc];
231		cbuf[offset + 1] = addr[nc] >> 8;
232	}
233
234	if (id == IPC_CMD_PCNTRL_R) {
235		for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
236			ipc_data_writel(scu, wbuf[nc], offset);
237		ipc_command(scu, (count * 2) << 16 | id << 12 | 0 << 8 | op);
238	} else if (id == IPC_CMD_PCNTRL_W) {
239		for (nc = 0; nc < count; nc++, offset += 1)
240			cbuf[offset] = data[nc];
241		for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
242			ipc_data_writel(scu, wbuf[nc], offset);
243		ipc_command(scu, (count * 3) << 16 | id << 12 | 0 << 8 | op);
244	} else if (id == IPC_CMD_PCNTRL_M) {
245		cbuf[offset] = data[0];
246		cbuf[offset + 1] = data[1];
247		ipc_data_writel(scu, wbuf[0], 0); /* Write wbuff */
248		ipc_command(scu, 4 << 16 | id << 12 | 0 << 8 | op);
249	}
250
251	err = intel_scu_ipc_check_status(scu);
252	if (!err && id == IPC_CMD_PCNTRL_R) { /* Read rbuf */
253		/* Workaround: values are read as 0 without memcpy_fromio */
254		memcpy_fromio(cbuf, scu->ipc_base + 0x90, 16);
255		for (nc = 0; nc < count; nc++)
256			data[nc] = ipc_data_readb(scu, nc);
257	}
258	mutex_unlock(&ipclock);
259	return err;
260}
261
262/**
263 *	intel_scu_ipc_ioread8		-	read a word via the SCU
264 *	@addr: register on SCU
265 *	@data: return pointer for read byte
266 *
267 *	Read a single register. Returns 0 on success or an error code. All
268 *	locking between SCU accesses is handled for the caller.
269 *
270 *	This function may sleep.
271 */
272int intel_scu_ipc_ioread8(u16 addr, u8 *data)
273{
274	return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
275}
276EXPORT_SYMBOL(intel_scu_ipc_ioread8);
277
278/**
279 *	intel_scu_ipc_ioread16		-	read a word via the SCU
280 *	@addr: register on SCU
281 *	@data: return pointer for read word
282 *
283 *	Read a register pair. Returns 0 on success or an error code. All
284 *	locking between SCU accesses is handled for the caller.
285 *
286 *	This function may sleep.
287 */
288int intel_scu_ipc_ioread16(u16 addr, u16 *data)
289{
290	u16 x[2] = {addr, addr + 1};
291	return pwr_reg_rdwr(x, (u8 *)data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
292}
293EXPORT_SYMBOL(intel_scu_ipc_ioread16);
294
295/**
296 *	intel_scu_ipc_ioread32		-	read a dword via the SCU
297 *	@addr: register on SCU
298 *	@data: return pointer for read dword
299 *
300 *	Read four registers. Returns 0 on success or an error code. All
301 *	locking between SCU accesses is handled for the caller.
302 *
303 *	This function may sleep.
304 */
305int intel_scu_ipc_ioread32(u16 addr, u32 *data)
306{
307	u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
308	return pwr_reg_rdwr(x, (u8 *)data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
309}
310EXPORT_SYMBOL(intel_scu_ipc_ioread32);
311
312/**
313 *	intel_scu_ipc_iowrite8		-	write a byte via the SCU
314 *	@addr: register on SCU
315 *	@data: byte to write
 
316 *
317 *	Write a single register. Returns 0 on success or an error code. All
318 *	locking between SCU accesses is handled for the caller.
319 *
320 *	This function may sleep.
321 */
322int intel_scu_ipc_iowrite8(u16 addr, u8 data)
323{
324	return pwr_reg_rdwr(&addr, &data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
325}
326EXPORT_SYMBOL(intel_scu_ipc_iowrite8);
327
328/**
329 *	intel_scu_ipc_iowrite16		-	write a word via the SCU
330 *	@addr: register on SCU
331 *	@data: word to write
 
 
332 *
333 *	Write two registers. Returns 0 on success or an error code. All
334 *	locking between SCU accesses is handled for the caller.
335 *
336 *	This function may sleep.
337 */
338int intel_scu_ipc_iowrite16(u16 addr, u16 data)
339{
340	u16 x[2] = {addr, addr + 1};
341	return pwr_reg_rdwr(x, (u8 *)&data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
342}
343EXPORT_SYMBOL(intel_scu_ipc_iowrite16);
344
345/**
346 *	intel_scu_ipc_iowrite32		-	write a dword via the SCU
347 *	@addr: register on SCU
348 *	@data: dword to write
349 *
350 *	Write four registers. Returns 0 on success or an error code. All
351 *	locking between SCU accesses is handled for the caller.
352 *
353 *	This function may sleep.
354 */
355int intel_scu_ipc_iowrite32(u16 addr, u32 data)
356{
357	u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
358	return pwr_reg_rdwr(x, (u8 *)&data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
359}
360EXPORT_SYMBOL(intel_scu_ipc_iowrite32);
361
362/**
363 *	intel_scu_ipc_readvv		-	read a set of registers
364 *	@addr: register list
365 *	@data: bytes to return
366 *	@len: length of array
367 *
368 *	Read registers. Returns 0 on success or an error code. All
369 *	locking between SCU accesses is handled for the caller.
370 *
371 *	The largest array length permitted by the hardware is 5 items.
372 *
373 *	This function may sleep.
374 */
375int intel_scu_ipc_readv(u16 *addr, u8 *data, int len)
 
376{
377	return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
378}
379EXPORT_SYMBOL(intel_scu_ipc_readv);
380
381/**
382 *	intel_scu_ipc_writev		-	write a set of registers
383 *	@addr: register list
384 *	@data: bytes to write
385 *	@len: length of array
386 *
387 *	Write registers. Returns 0 on success or an error code. All
388 *	locking between SCU accesses is handled for the caller.
389 *
390 *	The largest array length permitted by the hardware is 5 items.
 
391 *
392 *	This function may sleep.
393 *
 
394 */
395int intel_scu_ipc_writev(u16 *addr, u8 *data, int len)
 
396{
397	return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
398}
399EXPORT_SYMBOL(intel_scu_ipc_writev);
400
401/**
402 *	intel_scu_ipc_update_register	-	r/m/w a register
403 *	@addr: register address
404 *	@bits: bits to update
405 *	@mask: mask of bits to update
 
406 *
407 *	Read-modify-write power control unit register. The first data argument
408 *	must be register value and second is mask value
409 *	mask is a bitmap that indicates which bits to update.
410 *	0 = masked. Don't modify this bit, 1 = modify this bit.
411 *	returns 0 on success or an error code.
412 *
413 *	This function may sleep. Locking between SCU accesses is handled
414 *	for the caller.
415 */
416int intel_scu_ipc_update_register(u16 addr, u8 bits, u8 mask)
 
417{
418	u8 data[2] = { bits, mask };
419	return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_M);
420}
421EXPORT_SYMBOL(intel_scu_ipc_update_register);
422
423/**
424 *	intel_scu_ipc_simple_command	-	send a simple command
425 *	@cmd: command
426 *	@sub: sub type
 
427 *
428 *	Issue a simple command to the SCU. Do not use this interface if
429 *	you must then access data as any data values may be overwritten
430 *	by another SCU access by the time this function returns.
431 *
432 *	This function may sleep. Locking for SCU accesses is handled for
433 *	the caller.
434 */
435int intel_scu_ipc_simple_command(int cmd, int sub)
 
436{
437	struct intel_scu_ipc_dev *scu = &ipcdev;
438	int err;
439
440	mutex_lock(&ipclock);
441	if (scu->dev == NULL) {
 
 
442		mutex_unlock(&ipclock);
443		return -ENODEV;
444	}
445	ipc_command(scu, sub << 12 | cmd);
 
 
446	err = intel_scu_ipc_check_status(scu);
447	mutex_unlock(&ipclock);
 
 
448	return err;
449}
450EXPORT_SYMBOL(intel_scu_ipc_simple_command);
451
452/**
453 *	intel_scu_ipc_command	-	command with data
454 *	@cmd: command
455 *	@sub: sub type
456 *	@in: input data
457 *	@inlen: input length in dwords
458 *	@out: output data
459 *	@outlein: output length in dwords
460 *
461 *	Issue a command to the SCU which involves data transfers. Do the
462 *	data copies under the lock but leave it for the caller to interpret
463 */
464int intel_scu_ipc_command(int cmd, int sub, u32 *in, int inlen,
465			  u32 *out, int outlen)
466{
467	struct intel_scu_ipc_dev *scu = &ipcdev;
 
 
 
 
 
 
 
468	int i, err;
469
 
 
 
470	mutex_lock(&ipclock);
471	if (scu->dev == NULL) {
 
 
472		mutex_unlock(&ipclock);
473		return -ENODEV;
474	}
475
476	for (i = 0; i < inlen; i++)
477		ipc_data_writel(scu, *in++, 4 * i);
 
478
479	ipc_command(scu, (inlen << 16) | (sub << 12) | cmd);
 
480	err = intel_scu_ipc_check_status(scu);
481
482	if (!err) {
483		for (i = 0; i < outlen; i++)
484			*out++ = ipc_data_readl(scu, 4 * i);
 
 
 
 
485	}
486
487	mutex_unlock(&ipclock);
 
 
488	return err;
489}
490EXPORT_SYMBOL(intel_scu_ipc_command);
491
492#define IPC_SPTR		0x08
493#define IPC_DPTR		0x0C
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
494
495/**
496 * intel_scu_ipc_raw_command() - IPC command with data and pointers
497 * @cmd:	IPC command code.
498 * @sub:	IPC command sub type.
499 * @in:		input data of this IPC command.
500 * @inlen:	input data length in dwords.
501 * @out:	output data of this IPC command.
502 * @outlen:	output data length in dwords.
503 * @sptr:	data writing to SPTR register.
504 * @dptr:	data writing to DPTR register.
505 *
506 * Send an IPC command to SCU with input/output data and source/dest pointers.
507 *
508 * Return:	an IPC error code or 0 on success.
 
 
 
509 */
510int intel_scu_ipc_raw_command(int cmd, int sub, u8 *in, int inlen,
511			      u32 *out, int outlen, u32 dptr, u32 sptr)
 
 
512{
513	struct intel_scu_ipc_dev *scu = &ipcdev;
514	int inbuflen = DIV_ROUND_UP(inlen, 4);
515	u32 inbuf[4];
516	int i, err;
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
517
518	/* Up to 16 bytes */
519	if (inbuflen > 4)
520		return -EINVAL;
 
 
521
522	mutex_lock(&ipclock);
523	if (scu->dev == NULL) {
524		mutex_unlock(&ipclock);
525		return -ENODEV;
526	}
527
528	writel(dptr, scu->ipc_base + IPC_DPTR);
529	writel(sptr, scu->ipc_base + IPC_SPTR);
 
 
 
 
 
 
 
 
530
531	/*
532	 * SRAM controller doesn't support 8-bit writes, it only
533	 * supports 32-bit writes, so we have to copy input data into
534	 * the temporary buffer, and SCU FW will use the inlen to
535	 * determine the actual input data length in the temporary
536	 * buffer.
537	 */
538	memcpy(inbuf, in, inlen);
 
 
 
 
 
539
540	for (i = 0; i < inbuflen; i++)
541		ipc_data_writel(scu, inbuf[i], 4 * i);
 
542
543	ipc_command(scu, (inlen << 16) | (sub << 12) | cmd);
544	err = intel_scu_ipc_check_status(scu);
545	if (!err) {
546		for (i = 0; i < outlen; i++)
547			*out++ = ipc_data_readl(scu, 4 * i);
548	}
549
 
 
 
 
 
 
 
550	mutex_unlock(&ipclock);
551	return err;
 
552}
553EXPORT_SYMBOL_GPL(intel_scu_ipc_raw_command);
554
555/* I2C commands */
556#define IPC_I2C_WRITE 1 /* I2C Write command */
557#define IPC_I2C_READ  2 /* I2C Read command */
558
559/**
560 *	intel_scu_ipc_i2c_cntrl		-	I2C read/write operations
561 *	@addr: I2C address + command bits
562 *	@data: data to read/write
563 *
564 *	Perform an an I2C read/write operation via the SCU. All locking is
565 *	handled for the caller. This function may sleep.
566 *
567 *	Returns an error code or 0 on success.
568 *
569 *	This has to be in the IPC driver for the locking.
570 */
571int intel_scu_ipc_i2c_cntrl(u32 addr, u32 *data)
572{
573	struct intel_scu_ipc_dev *scu = &ipcdev;
574	u32 cmd = 0;
575
576	mutex_lock(&ipclock);
577	if (scu->dev == NULL) {
578		mutex_unlock(&ipclock);
579		return -ENODEV;
580	}
581	cmd = (addr >> 24) & 0xFF;
582	if (cmd == IPC_I2C_READ) {
583		writel(addr, scu->i2c_base + IPC_I2C_CNTRL_ADDR);
584		/* Write not getting updated without delay */
585		usleep_range(1000, 2000);
586		*data = readl(scu->i2c_base + I2C_DATA_ADDR);
587	} else if (cmd == IPC_I2C_WRITE) {
588		writel(*data, scu->i2c_base + I2C_DATA_ADDR);
589		usleep_range(1000, 2000);
590		writel(addr, scu->i2c_base + IPC_I2C_CNTRL_ADDR);
591	} else {
592		dev_err(scu->dev,
593			"intel_scu_ipc: I2C INVALID_CMD = 0x%x\n", cmd);
594
595		mutex_unlock(&ipclock);
596		return -EIO;
597	}
598	mutex_unlock(&ipclock);
599	return 0;
600}
601EXPORT_SYMBOL(intel_scu_ipc_i2c_cntrl);
602
603/*
604 * Interrupt handler gets called when ioc bit of IPC_COMMAND_REG set to 1
605 * When ioc bit is set to 1, caller api must wait for interrupt handler called
606 * which in turn unlocks the caller api. Currently this is not used
607 *
608 * This is edge triggered so we need take no action to clear anything
609 */
610static irqreturn_t ioc(int irq, void *dev_id)
611{
612	struct intel_scu_ipc_dev *scu = dev_id;
 
613
614	if (scu->irq_mode)
615		complete(&scu->cmd_complete);
616
617	return IRQ_HANDLED;
618}
619
620/**
621 *	ipc_probe	-	probe an Intel SCU IPC
622 *	@pdev: the PCI device matching
623 *	@id: entry in the match table
 
624 *
625 *	Enable and install an intel SCU IPC. This appears in the PCI space
626 *	but uses some hard coded addresses as well.
 
 
627 */
628static int ipc_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 
 
 
629{
630	int err;
631	struct intel_scu_ipc_dev *scu = &ipcdev;
632	struct intel_scu_ipc_pdata_t *pdata;
633
634	if (scu->dev)		/* We support only one SCU */
635		return -EBUSY;
 
636
637	pdata = (struct intel_scu_ipc_pdata_t *)id->driver_data;
638	if (!pdata)
639		return -ENODEV;
 
 
640
641	scu->irq_mode = pdata->irq_mode;
 
642
643	err = pcim_enable_device(pdev);
644	if (err)
645		return err;
646
647	err = pcim_iomap_regions(pdev, 1 << 0, pci_name(pdev));
648	if (err)
649		return err;
 
 
650
651	init_completion(&scu->cmd_complete);
652
653	scu->ipc_base = pcim_iomap_table(pdev)[0];
654
655	scu->i2c_base = ioremap_nocache(pdata->i2c_base, pdata->i2c_len);
656	if (!scu->i2c_base)
657		return -ENOMEM;
658
659	err = devm_request_irq(&pdev->dev, pdev->irq, ioc, 0, "intel_scu_ipc",
660			       scu);
661	if (err)
662		return err;
663
664	/* Assign device at last */
665	scu->dev = &pdev->dev;
666
667	intel_scu_devices_create();
668
669	pci_set_drvdata(pdev, scu);
670	return 0;
671}
672
673#define SCU_DEVICE(id, pdata)	{PCI_VDEVICE(INTEL, id), (kernel_ulong_t)&pdata}
674
675static const struct pci_device_id pci_ids[] = {
676	SCU_DEVICE(PCI_DEVICE_ID_LINCROFT,	intel_scu_ipc_lincroft_pdata),
677	SCU_DEVICE(PCI_DEVICE_ID_PENWELL,	intel_scu_ipc_penwell_pdata),
678	SCU_DEVICE(PCI_DEVICE_ID_CLOVERVIEW,	intel_scu_ipc_penwell_pdata),
679	SCU_DEVICE(PCI_DEVICE_ID_TANGIER,	intel_scu_ipc_tangier_pdata),
680	{}
681};
682
683static struct pci_driver ipc_driver = {
684	.driver = {
685		.suppress_bind_attrs = true,
686	},
687	.name = "intel_scu_ipc",
688	.id_table = pci_ids,
689	.probe = ipc_probe,
690};
691builtin_pci_driver(ipc_driver);