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v3.1
  1/*
  2 * intel_scu_ipc.c: Driver for the Intel SCU IPC mechanism
  3 *
  4 * (C) Copyright 2008-2010 Intel Corporation
  5 * Author: Sreedhara DS (sreedhara.ds@intel.com)
  6 *
  7 * This program is free software; you can redistribute it and/or
  8 * modify it under the terms of the GNU General Public License
  9 * as published by the Free Software Foundation; version 2
 10 * of the License.
 11 *
 12 * SCU running in ARC processor communicates with other entity running in IA
 13 * core through IPC mechanism which in turn messaging between IA core ad SCU.
 14 * SCU has two IPC mechanism IPC-1 and IPC-2. IPC-1 is used between IA32 and
 15 * SCU where IPC-2 is used between P-Unit and SCU. This driver delas with
 16 * IPC-1 Driver provides an API for power control unit registers (e.g. MSIC)
 17 * along with other APIs.
 18 */
 19#include <linux/delay.h>
 20#include <linux/errno.h>
 21#include <linux/init.h>
 22#include <linux/sysdev.h>
 23#include <linux/pm.h>
 24#include <linux/pci.h>
 25#include <linux/interrupt.h>
 26#include <linux/sfi.h>
 
 27#include <asm/mrst.h>
 28#include <asm/intel_scu_ipc.h>
 29
 30/* IPC defines the following message types */
 31#define IPCMSG_WATCHDOG_TIMER 0xF8 /* Set Kernel Watchdog Threshold */
 32#define IPCMSG_BATTERY        0xEF /* Coulomb Counter Accumulator */
 33#define IPCMSG_FW_UPDATE      0xFE /* Firmware update */
 34#define IPCMSG_PCNTRL         0xFF /* Power controller unit read/write */
 35#define IPCMSG_FW_REVISION    0xF4 /* Get firmware revision */
 36
 37/* Command id associated with message IPCMSG_PCNTRL */
 38#define IPC_CMD_PCNTRL_W      0 /* Register write */
 39#define IPC_CMD_PCNTRL_R      1 /* Register read */
 40#define IPC_CMD_PCNTRL_M      2 /* Register read-modify-write */
 41
 42/*
 43 * IPC register summary
 44 *
 45 * IPC register blocks are memory mapped at fixed address of 0xFF11C000
 46 * To read or write information to the SCU, driver writes to IPC-1 memory
 47 * mapped registers (base address 0xFF11C000). The following is the IPC
 48 * mechanism
 49 *
 50 * 1. IA core cDMI interface claims this transaction and converts it to a
 51 *    Transaction Layer Packet (TLP) message which is sent across the cDMI.
 52 *
 53 * 2. South Complex cDMI block receives this message and writes it to
 54 *    the IPC-1 register block, causing an interrupt to the SCU
 55 *
 56 * 3. SCU firmware decodes this interrupt and IPC message and the appropriate
 57 *    message handler is called within firmware.
 58 */
 59
 60#define IPC_BASE_ADDR     0xFF11C000	/* IPC1 base register address */
 61#define IPC_MAX_ADDR      0x100		/* Maximum IPC regisers */
 62#define IPC_WWBUF_SIZE    20		/* IPC Write buffer Size */
 63#define IPC_RWBUF_SIZE    20		/* IPC Read buffer Size */
 64#define IPC_I2C_BASE      0xFF12B000	/* I2C control register base address */
 65#define IPC_I2C_MAX_ADDR  0x10		/* Maximum I2C regisers */
 66
 67static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id);
 68static void ipc_remove(struct pci_dev *pdev);
 69
 70struct intel_scu_ipc_dev {
 71	struct pci_dev *pdev;
 72	void __iomem *ipc_base;
 73	void __iomem *i2c_base;
 74};
 75
 76static struct intel_scu_ipc_dev  ipcdev; /* Only one for now */
 77
 78static int platform;		/* Platform type */
 79
 80/*
 81 * IPC Read Buffer (Read Only):
 82 * 16 byte buffer for receiving data from SCU, if IPC command
 83 * processing results in response data
 84 */
 85#define IPC_READ_BUFFER		0x90
 86
 87#define IPC_I2C_CNTRL_ADDR	0
 88#define I2C_DATA_ADDR		0x04
 89
 90static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
 91
 92/*
 93 * Command Register (Write Only):
 94 * A write to this register results in an interrupt to the SCU core processor
 95 * Format:
 96 * |rfu2(8) | size(8) | command id(4) | rfu1(3) | ioc(1) | command(8)|
 97 */
 98static inline void ipc_command(u32 cmd) /* Send ipc command */
 99{
100	writel(cmd, ipcdev.ipc_base);
101}
102
103/*
104 * IPC Write Buffer (Write Only):
105 * 16-byte buffer for sending data associated with IPC command to
106 * SCU. Size of the data is specified in the IPC_COMMAND_REG register
107 */
108static inline void ipc_data_writel(u32 data, u32 offset) /* Write ipc data */
109{
110	writel(data, ipcdev.ipc_base + 0x80 + offset);
111}
112
113/*
114 * Status Register (Read Only):
115 * Driver will read this register to get the ready/busy status of the IPC
116 * block and error status of the IPC command that was just processed by SCU
117 * Format:
118 * |rfu3(8)|error code(8)|initiator id(8)|cmd id(4)|rfu1(2)|error(1)|busy(1)|
119 */
120
121static inline u8 ipc_read_status(void)
122{
123	return __raw_readl(ipcdev.ipc_base + 0x04);
124}
125
126static inline u8 ipc_data_readb(u32 offset) /* Read ipc byte data */
127{
128	return readb(ipcdev.ipc_base + IPC_READ_BUFFER + offset);
129}
130
131static inline u32 ipc_data_readl(u32 offset) /* Read ipc u32 data */
132{
133	return readl(ipcdev.ipc_base + IPC_READ_BUFFER + offset);
134}
135
136static inline int busy_loop(void) /* Wait till scu status is busy */
137{
138	u32 status = 0;
139	u32 loop_count = 0;
140
141	status = ipc_read_status();
142	while (status & 1) {
143		udelay(1); /* scu processing time is in few u secods */
144		status = ipc_read_status();
145		loop_count++;
146		/* break if scu doesn't reset busy bit after huge retry */
147		if (loop_count > 100000) {
148			dev_err(&ipcdev.pdev->dev, "IPC timed out");
149			return -ETIMEDOUT;
150		}
151	}
152	if ((status >> 1) & 1)
153		return -EIO;
154
155	return 0;
156}
157
158/* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
159static int pwr_reg_rdwr(u16 *addr, u8 *data, u32 count, u32 op, u32 id)
160{
161	int i, nc, bytes, d;
162	u32 offset = 0;
163	int err;
164	u8 cbuf[IPC_WWBUF_SIZE] = { };
165	u32 *wbuf = (u32 *)&cbuf;
166
167	mutex_lock(&ipclock);
168
169	memset(cbuf, 0, sizeof(cbuf));
170
171	if (ipcdev.pdev == NULL) {
172		mutex_unlock(&ipclock);
173		return -ENODEV;
174	}
175
176	if (platform != MRST_CPU_CHIP_PENWELL) {
177		bytes = 0;
178		d = 0;
179		for (i = 0; i < count; i++) {
180			cbuf[bytes++] = addr[i];
181			cbuf[bytes++] = addr[i] >> 8;
182			if (id != IPC_CMD_PCNTRL_R)
183				cbuf[bytes++] = data[d++];
184			if (id == IPC_CMD_PCNTRL_M)
185				cbuf[bytes++] = data[d++];
186		}
187		for (i = 0; i < bytes; i += 4)
188			ipc_data_writel(wbuf[i/4], i);
189		ipc_command(bytes << 16 |  id << 12 | 0 << 8 | op);
190	} else {
191		for (nc = 0; nc < count; nc++, offset += 2) {
192			cbuf[offset] = addr[nc];
193			cbuf[offset + 1] = addr[nc] >> 8;
194		}
195
196		if (id == IPC_CMD_PCNTRL_R) {
197			for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
198				ipc_data_writel(wbuf[nc], offset);
199			ipc_command((count*2) << 16 |  id << 12 | 0 << 8 | op);
200		} else if (id == IPC_CMD_PCNTRL_W) {
201			for (nc = 0; nc < count; nc++, offset += 1)
202				cbuf[offset] = data[nc];
203			for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
204				ipc_data_writel(wbuf[nc], offset);
205			ipc_command((count*3) << 16 |  id << 12 | 0 << 8 | op);
206		} else if (id == IPC_CMD_PCNTRL_M) {
207			cbuf[offset] = data[0];
208			cbuf[offset + 1] = data[1];
209			ipc_data_writel(wbuf[0], 0); /* Write wbuff */
210			ipc_command(4 << 16 |  id << 12 | 0 << 8 | op);
211		}
212	}
213
214	err = busy_loop();
215	if (id == IPC_CMD_PCNTRL_R) { /* Read rbuf */
216		/* Workaround: values are read as 0 without memcpy_fromio */
217		memcpy_fromio(cbuf, ipcdev.ipc_base + 0x90, 16);
218		if (platform != MRST_CPU_CHIP_PENWELL) {
219			for (nc = 0, offset = 2; nc < count; nc++, offset += 3)
220				data[nc] = ipc_data_readb(offset);
221		} else {
222			for (nc = 0; nc < count; nc++)
223				data[nc] = ipc_data_readb(nc);
224		}
225	}
226	mutex_unlock(&ipclock);
227	return err;
228}
229
230/**
231 *	intel_scu_ipc_ioread8		-	read a word via the SCU
232 *	@addr: register on SCU
233 *	@data: return pointer for read byte
234 *
235 *	Read a single register. Returns 0 on success or an error code. All
236 *	locking between SCU accesses is handled for the caller.
237 *
238 *	This function may sleep.
239 */
240int intel_scu_ipc_ioread8(u16 addr, u8 *data)
241{
242	return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
243}
244EXPORT_SYMBOL(intel_scu_ipc_ioread8);
245
246/**
247 *	intel_scu_ipc_ioread16		-	read a word via the SCU
248 *	@addr: register on SCU
249 *	@data: return pointer for read word
250 *
251 *	Read a register pair. Returns 0 on success or an error code. All
252 *	locking between SCU accesses is handled for the caller.
253 *
254 *	This function may sleep.
255 */
256int intel_scu_ipc_ioread16(u16 addr, u16 *data)
257{
258	u16 x[2] = {addr, addr + 1 };
259	return pwr_reg_rdwr(x, (u8 *)data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
260}
261EXPORT_SYMBOL(intel_scu_ipc_ioread16);
262
263/**
264 *	intel_scu_ipc_ioread32		-	read a dword via the SCU
265 *	@addr: register on SCU
266 *	@data: return pointer for read dword
267 *
268 *	Read four registers. Returns 0 on success or an error code. All
269 *	locking between SCU accesses is handled for the caller.
270 *
271 *	This function may sleep.
272 */
273int intel_scu_ipc_ioread32(u16 addr, u32 *data)
274{
275	u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
276	return pwr_reg_rdwr(x, (u8 *)data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
277}
278EXPORT_SYMBOL(intel_scu_ipc_ioread32);
279
280/**
281 *	intel_scu_ipc_iowrite8		-	write a byte via the SCU
282 *	@addr: register on SCU
283 *	@data: byte to write
284 *
285 *	Write a single register. Returns 0 on success or an error code. All
286 *	locking between SCU accesses is handled for the caller.
287 *
288 *	This function may sleep.
289 */
290int intel_scu_ipc_iowrite8(u16 addr, u8 data)
291{
292	return pwr_reg_rdwr(&addr, &data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
293}
294EXPORT_SYMBOL(intel_scu_ipc_iowrite8);
295
296/**
297 *	intel_scu_ipc_iowrite16		-	write a word via the SCU
298 *	@addr: register on SCU
299 *	@data: word to write
300 *
301 *	Write two registers. Returns 0 on success or an error code. All
302 *	locking between SCU accesses is handled for the caller.
303 *
304 *	This function may sleep.
305 */
306int intel_scu_ipc_iowrite16(u16 addr, u16 data)
307{
308	u16 x[2] = {addr, addr + 1 };
309	return pwr_reg_rdwr(x, (u8 *)&data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
310}
311EXPORT_SYMBOL(intel_scu_ipc_iowrite16);
312
313/**
314 *	intel_scu_ipc_iowrite32		-	write a dword via the SCU
315 *	@addr: register on SCU
316 *	@data: dword to write
317 *
318 *	Write four registers. Returns 0 on success or an error code. All
319 *	locking between SCU accesses is handled for the caller.
320 *
321 *	This function may sleep.
322 */
323int intel_scu_ipc_iowrite32(u16 addr, u32 data)
324{
325	u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
326	return pwr_reg_rdwr(x, (u8 *)&data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
327}
328EXPORT_SYMBOL(intel_scu_ipc_iowrite32);
329
330/**
331 *	intel_scu_ipc_readvv		-	read a set of registers
332 *	@addr: register list
333 *	@data: bytes to return
334 *	@len: length of array
335 *
336 *	Read registers. Returns 0 on success or an error code. All
337 *	locking between SCU accesses is handled for the caller.
338 *
339 *	The largest array length permitted by the hardware is 5 items.
340 *
341 *	This function may sleep.
342 */
343int intel_scu_ipc_readv(u16 *addr, u8 *data, int len)
344{
345	return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
346}
347EXPORT_SYMBOL(intel_scu_ipc_readv);
348
349/**
350 *	intel_scu_ipc_writev		-	write a set of registers
351 *	@addr: register list
352 *	@data: bytes to write
353 *	@len: length of array
354 *
355 *	Write registers. Returns 0 on success or an error code. All
356 *	locking between SCU accesses is handled for the caller.
357 *
358 *	The largest array length permitted by the hardware is 5 items.
359 *
360 *	This function may sleep.
361 *
362 */
363int intel_scu_ipc_writev(u16 *addr, u8 *data, int len)
364{
365	return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
366}
367EXPORT_SYMBOL(intel_scu_ipc_writev);
368
369
370/**
371 *	intel_scu_ipc_update_register	-	r/m/w a register
372 *	@addr: register address
373 *	@bits: bits to update
374 *	@mask: mask of bits to update
375 *
376 *	Read-modify-write power control unit register. The first data argument
377 *	must be register value and second is mask value
378 *	mask is a bitmap that indicates which bits to update.
379 *	0 = masked. Don't modify this bit, 1 = modify this bit.
380 *	returns 0 on success or an error code.
381 *
382 *	This function may sleep. Locking between SCU accesses is handled
383 *	for the caller.
384 */
385int intel_scu_ipc_update_register(u16 addr, u8 bits, u8 mask)
386{
387	u8 data[2] = { bits, mask };
388	return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_M);
389}
390EXPORT_SYMBOL(intel_scu_ipc_update_register);
391
392/**
393 *	intel_scu_ipc_simple_command	-	send a simple command
394 *	@cmd: command
395 *	@sub: sub type
396 *
397 *	Issue a simple command to the SCU. Do not use this interface if
398 *	you must then access data as any data values may be overwritten
399 *	by another SCU access by the time this function returns.
400 *
401 *	This function may sleep. Locking for SCU accesses is handled for
402 *	the caller.
403 */
404int intel_scu_ipc_simple_command(int cmd, int sub)
405{
406	int err;
407
408	mutex_lock(&ipclock);
409	if (ipcdev.pdev == NULL) {
410		mutex_unlock(&ipclock);
411		return -ENODEV;
412	}
413	ipc_command(sub << 12 | cmd);
414	err = busy_loop();
415	mutex_unlock(&ipclock);
416	return err;
417}
418EXPORT_SYMBOL(intel_scu_ipc_simple_command);
419
420/**
421 *	intel_scu_ipc_command	-	command with data
422 *	@cmd: command
423 *	@sub: sub type
424 *	@in: input data
425 *	@inlen: input length in dwords
426 *	@out: output data
427 *	@outlein: output length in dwords
428 *
429 *	Issue a command to the SCU which involves data transfers. Do the
430 *	data copies under the lock but leave it for the caller to interpret
431 */
432
433int intel_scu_ipc_command(int cmd, int sub, u32 *in, int inlen,
434							u32 *out, int outlen)
435{
436	int i, err;
437
438	mutex_lock(&ipclock);
439	if (ipcdev.pdev == NULL) {
440		mutex_unlock(&ipclock);
441		return -ENODEV;
442	}
443
444	for (i = 0; i < inlen; i++)
445		ipc_data_writel(*in++, 4 * i);
446
447	ipc_command((inlen << 16) | (sub << 12) | cmd);
448	err = busy_loop();
449
450	for (i = 0; i < outlen; i++)
451		*out++ = ipc_data_readl(4 * i);
452
453	mutex_unlock(&ipclock);
454	return err;
455}
456EXPORT_SYMBOL(intel_scu_ipc_command);
457
458/*I2C commands */
459#define IPC_I2C_WRITE 1 /* I2C Write command */
460#define IPC_I2C_READ  2 /* I2C Read command */
461
462/**
463 *	intel_scu_ipc_i2c_cntrl		-	I2C read/write operations
464 *	@addr: I2C address + command bits
465 *	@data: data to read/write
466 *
467 *	Perform an an I2C read/write operation via the SCU. All locking is
468 *	handled for the caller. This function may sleep.
469 *
470 *	Returns an error code or 0 on success.
471 *
472 *	This has to be in the IPC driver for the locking.
473 */
474int intel_scu_ipc_i2c_cntrl(u32 addr, u32 *data)
475{
476	u32 cmd = 0;
477
478	mutex_lock(&ipclock);
479	if (ipcdev.pdev == NULL) {
480		mutex_unlock(&ipclock);
481		return -ENODEV;
482	}
483	cmd = (addr >> 24) & 0xFF;
484	if (cmd == IPC_I2C_READ) {
485		writel(addr, ipcdev.i2c_base + IPC_I2C_CNTRL_ADDR);
486		/* Write not getting updated without delay */
487		mdelay(1);
488		*data = readl(ipcdev.i2c_base + I2C_DATA_ADDR);
489	} else if (cmd == IPC_I2C_WRITE) {
490		writel(*data, ipcdev.i2c_base + I2C_DATA_ADDR);
491		mdelay(1);
492		writel(addr, ipcdev.i2c_base + IPC_I2C_CNTRL_ADDR);
493	} else {
494		dev_err(&ipcdev.pdev->dev,
495			"intel_scu_ipc: I2C INVALID_CMD = 0x%x\n", cmd);
496
497		mutex_unlock(&ipclock);
498		return -EIO;
499	}
500	mutex_unlock(&ipclock);
501	return 0;
502}
503EXPORT_SYMBOL(intel_scu_ipc_i2c_cntrl);
504
505#define IPC_FW_LOAD_ADDR 0xFFFC0000 /* Storage location for FW image */
506#define IPC_FW_UPDATE_MBOX_ADDR 0xFFFFDFF4 /* Mailbox between ipc and scu */
507#define IPC_MAX_FW_SIZE 262144 /* 256K storage size for loading the FW image */
508#define IPC_FW_MIP_HEADER_SIZE 2048 /* Firmware MIP header size */
509/* IPC inform SCU to get ready for update process */
510#define IPC_CMD_FW_UPDATE_READY  0x10FE
511/* IPC inform SCU to go for update process */
512#define IPC_CMD_FW_UPDATE_GO     0x20FE
513/* Status code for fw update */
514#define IPC_FW_UPDATE_SUCCESS	0x444f4e45 /* Status code 'DONE' */
515#define IPC_FW_UPDATE_BADN	0x4241444E /* Status code 'BADN' */
516#define IPC_FW_TXHIGH		0x54784849 /* Status code 'IPC_FW_TXHIGH' */
517#define IPC_FW_TXLOW		0x54784c4f /* Status code 'IPC_FW_TXLOW' */
518
519struct fw_update_mailbox {
520	u32    status;
521	u32    scu_flag;
522	u32    driver_flag;
523};
524
525
526/**
527 *	intel_scu_ipc_fw_update	-	 Firmware update utility
528 *	@buffer: firmware buffer
529 *	@length: size of firmware buffer
530 *
531 *	This function provides an interface to load the firmware into
532 *	the SCU. Returns 0 on success or -1 on failure
533 */
534int intel_scu_ipc_fw_update(u8 *buffer, u32 length)
535{
536	void __iomem *fw_update_base;
537	struct fw_update_mailbox __iomem *mailbox = NULL;
538	int retry_cnt = 0;
539	u32 status;
540
541	mutex_lock(&ipclock);
542	fw_update_base = ioremap_nocache(IPC_FW_LOAD_ADDR, (128*1024));
543	if (fw_update_base == NULL) {
544		mutex_unlock(&ipclock);
545		return -ENOMEM;
546	}
547	mailbox = ioremap_nocache(IPC_FW_UPDATE_MBOX_ADDR,
548					sizeof(struct fw_update_mailbox));
549	if (mailbox == NULL) {
550		iounmap(fw_update_base);
551		mutex_unlock(&ipclock);
552		return -ENOMEM;
553	}
554
555	ipc_command(IPC_CMD_FW_UPDATE_READY);
556
557	/* Intitialize mailbox */
558	writel(0, &mailbox->status);
559	writel(0, &mailbox->scu_flag);
560	writel(0, &mailbox->driver_flag);
561
562	/* Driver copies the 2KB MIP header to SRAM at 0xFFFC0000*/
563	memcpy_toio(fw_update_base, buffer, 0x800);
564
565	/* Driver sends "FW Update" IPC command (CMD_ID 0xFE; MSG_ID 0x02).
566	* Upon receiving this command, SCU will write the 2K MIP header
567	* from 0xFFFC0000 into NAND.
568	* SCU will write a status code into the Mailbox, and then set scu_flag.
569	*/
570
571	ipc_command(IPC_CMD_FW_UPDATE_GO);
572
573	/*Driver stalls until scu_flag is set */
574	while (readl(&mailbox->scu_flag) != 1) {
575		rmb();
576		mdelay(1);
577	}
578
579	/* Driver checks Mailbox status.
580	 * If the status is 'BADN', then abort (bad NAND).
581	 * If the status is 'IPC_FW_TXLOW', then continue.
582	 */
583	while (readl(&mailbox->status) != IPC_FW_TXLOW) {
584		rmb();
585		mdelay(10);
586	}
587	mdelay(10);
588
589update_retry:
590	if (retry_cnt > 5)
591		goto update_end;
592
593	if (readl(&mailbox->status) != IPC_FW_TXLOW)
594		goto update_end;
595	buffer = buffer + 0x800;
596	memcpy_toio(fw_update_base, buffer, 0x20000);
597	writel(1, &mailbox->driver_flag);
598	while (readl(&mailbox->scu_flag) == 1) {
599		rmb();
600		mdelay(1);
601	}
602
603	/* check for 'BADN' */
604	if (readl(&mailbox->status) == IPC_FW_UPDATE_BADN)
605		goto update_end;
606
607	while (readl(&mailbox->status) != IPC_FW_TXHIGH) {
608		rmb();
609		mdelay(10);
610	}
611	mdelay(10);
612
613	if (readl(&mailbox->status) != IPC_FW_TXHIGH)
614		goto update_end;
615
616	buffer = buffer + 0x20000;
617	memcpy_toio(fw_update_base, buffer, 0x20000);
618	writel(0, &mailbox->driver_flag);
619
620	while (mailbox->scu_flag == 0) {
621		rmb();
622		mdelay(1);
623	}
624
625	/* check for 'BADN' */
626	if (readl(&mailbox->status) == IPC_FW_UPDATE_BADN)
627		goto update_end;
628
629	if (readl(&mailbox->status) == IPC_FW_TXLOW) {
630		++retry_cnt;
631		goto update_retry;
632	}
633
634update_end:
635	status = readl(&mailbox->status);
636
637	iounmap(fw_update_base);
638	iounmap(mailbox);
639	mutex_unlock(&ipclock);
640
641	if (status == IPC_FW_UPDATE_SUCCESS)
642		return 0;
643	return -EIO;
644}
645EXPORT_SYMBOL(intel_scu_ipc_fw_update);
646
647/*
648 * Interrupt handler gets called when ioc bit of IPC_COMMAND_REG set to 1
649 * When ioc bit is set to 1, caller api must wait for interrupt handler called
650 * which in turn unlocks the caller api. Currently this is not used
651 *
652 * This is edge triggered so we need take no action to clear anything
653 */
654static irqreturn_t ioc(int irq, void *dev_id)
655{
656	return IRQ_HANDLED;
657}
658
659/**
660 *	ipc_probe	-	probe an Intel SCU IPC
661 *	@dev: the PCI device matching
662 *	@id: entry in the match table
663 *
664 *	Enable and install an intel SCU IPC. This appears in the PCI space
665 *	but uses some hard coded addresses as well.
666 */
667static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id)
668{
669	int err;
670	resource_size_t pci_resource;
671
672	if (ipcdev.pdev)		/* We support only one SCU */
673		return -EBUSY;
674
675	ipcdev.pdev = pci_dev_get(dev);
676
677	err = pci_enable_device(dev);
678	if (err)
679		return err;
680
681	err = pci_request_regions(dev, "intel_scu_ipc");
682	if (err)
683		return err;
684
685	pci_resource = pci_resource_start(dev, 0);
686	if (!pci_resource)
687		return -ENOMEM;
688
689	if (request_irq(dev->irq, ioc, 0, "intel_scu_ipc", &ipcdev))
690		return -EBUSY;
691
692	ipcdev.ipc_base = ioremap_nocache(IPC_BASE_ADDR, IPC_MAX_ADDR);
693	if (!ipcdev.ipc_base)
694		return -ENOMEM;
695
696	ipcdev.i2c_base = ioremap_nocache(IPC_I2C_BASE, IPC_I2C_MAX_ADDR);
697	if (!ipcdev.i2c_base) {
698		iounmap(ipcdev.ipc_base);
699		return -ENOMEM;
700	}
701
702	intel_scu_devices_create();
703
704	return 0;
705}
706
707/**
708 *	ipc_remove	-	remove a bound IPC device
709 *	@pdev: PCI device
710 *
711 *	In practice the SCU is not removable but this function is also
712 *	called for each device on a module unload or cleanup which is the
713 *	path that will get used.
714 *
715 *	Free up the mappings and release the PCI resources
716 */
717static void ipc_remove(struct pci_dev *pdev)
718{
719	free_irq(pdev->irq, &ipcdev);
720	pci_release_regions(pdev);
721	pci_dev_put(ipcdev.pdev);
722	iounmap(ipcdev.ipc_base);
723	iounmap(ipcdev.i2c_base);
724	ipcdev.pdev = NULL;
725	intel_scu_devices_destroy();
726}
727
728static DEFINE_PCI_DEVICE_TABLE(pci_ids) = {
729	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x080e)},
730	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x082a)},
731	{ 0,}
732};
733MODULE_DEVICE_TABLE(pci, pci_ids);
734
735static struct pci_driver ipc_driver = {
736	.name = "intel_scu_ipc",
737	.id_table = pci_ids,
738	.probe = ipc_probe,
739	.remove = ipc_remove,
740};
741
742
743static int __init intel_scu_ipc_init(void)
744{
745	platform = mrst_identify_cpu();
746	if (platform == 0)
747		return -ENODEV;
748	return  pci_register_driver(&ipc_driver);
749}
750
751static void __exit intel_scu_ipc_exit(void)
752{
753	pci_unregister_driver(&ipc_driver);
754}
755
756MODULE_AUTHOR("Sreedhara DS <sreedhara.ds@intel.com>");
757MODULE_DESCRIPTION("Intel SCU IPC driver");
758MODULE_LICENSE("GPL");
759
760module_init(intel_scu_ipc_init);
761module_exit(intel_scu_ipc_exit);
v3.5.6
  1/*
  2 * intel_scu_ipc.c: Driver for the Intel SCU IPC mechanism
  3 *
  4 * (C) Copyright 2008-2010 Intel Corporation
  5 * Author: Sreedhara DS (sreedhara.ds@intel.com)
  6 *
  7 * This program is free software; you can redistribute it and/or
  8 * modify it under the terms of the GNU General Public License
  9 * as published by the Free Software Foundation; version 2
 10 * of the License.
 11 *
 12 * SCU running in ARC processor communicates with other entity running in IA
 13 * core through IPC mechanism which in turn messaging between IA core ad SCU.
 14 * SCU has two IPC mechanism IPC-1 and IPC-2. IPC-1 is used between IA32 and
 15 * SCU where IPC-2 is used between P-Unit and SCU. This driver delas with
 16 * IPC-1 Driver provides an API for power control unit registers (e.g. MSIC)
 17 * along with other APIs.
 18 */
 19#include <linux/delay.h>
 20#include <linux/errno.h>
 21#include <linux/init.h>
 22#include <linux/device.h>
 23#include <linux/pm.h>
 24#include <linux/pci.h>
 25#include <linux/interrupt.h>
 26#include <linux/sfi.h>
 27#include <linux/module.h>
 28#include <asm/mrst.h>
 29#include <asm/intel_scu_ipc.h>
 30
 31/* IPC defines the following message types */
 32#define IPCMSG_WATCHDOG_TIMER 0xF8 /* Set Kernel Watchdog Threshold */
 33#define IPCMSG_BATTERY        0xEF /* Coulomb Counter Accumulator */
 34#define IPCMSG_FW_UPDATE      0xFE /* Firmware update */
 35#define IPCMSG_PCNTRL         0xFF /* Power controller unit read/write */
 36#define IPCMSG_FW_REVISION    0xF4 /* Get firmware revision */
 37
 38/* Command id associated with message IPCMSG_PCNTRL */
 39#define IPC_CMD_PCNTRL_W      0 /* Register write */
 40#define IPC_CMD_PCNTRL_R      1 /* Register read */
 41#define IPC_CMD_PCNTRL_M      2 /* Register read-modify-write */
 42
 43/*
 44 * IPC register summary
 45 *
 46 * IPC register blocks are memory mapped at fixed address of 0xFF11C000
 47 * To read or write information to the SCU, driver writes to IPC-1 memory
 48 * mapped registers (base address 0xFF11C000). The following is the IPC
 49 * mechanism
 50 *
 51 * 1. IA core cDMI interface claims this transaction and converts it to a
 52 *    Transaction Layer Packet (TLP) message which is sent across the cDMI.
 53 *
 54 * 2. South Complex cDMI block receives this message and writes it to
 55 *    the IPC-1 register block, causing an interrupt to the SCU
 56 *
 57 * 3. SCU firmware decodes this interrupt and IPC message and the appropriate
 58 *    message handler is called within firmware.
 59 */
 60
 61#define IPC_BASE_ADDR     0xFF11C000	/* IPC1 base register address */
 62#define IPC_MAX_ADDR      0x100		/* Maximum IPC regisers */
 63#define IPC_WWBUF_SIZE    20		/* IPC Write buffer Size */
 64#define IPC_RWBUF_SIZE    20		/* IPC Read buffer Size */
 65#define IPC_I2C_BASE      0xFF12B000	/* I2C control register base address */
 66#define IPC_I2C_MAX_ADDR  0x10		/* Maximum I2C regisers */
 67
 68static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id);
 69static void ipc_remove(struct pci_dev *pdev);
 70
 71struct intel_scu_ipc_dev {
 72	struct pci_dev *pdev;
 73	void __iomem *ipc_base;
 74	void __iomem *i2c_base;
 75};
 76
 77static struct intel_scu_ipc_dev  ipcdev; /* Only one for now */
 78
 79static int platform;		/* Platform type */
 80
 81/*
 82 * IPC Read Buffer (Read Only):
 83 * 16 byte buffer for receiving data from SCU, if IPC command
 84 * processing results in response data
 85 */
 86#define IPC_READ_BUFFER		0x90
 87
 88#define IPC_I2C_CNTRL_ADDR	0
 89#define I2C_DATA_ADDR		0x04
 90
 91static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
 92
 93/*
 94 * Command Register (Write Only):
 95 * A write to this register results in an interrupt to the SCU core processor
 96 * Format:
 97 * |rfu2(8) | size(8) | command id(4) | rfu1(3) | ioc(1) | command(8)|
 98 */
 99static inline void ipc_command(u32 cmd) /* Send ipc command */
100{
101	writel(cmd, ipcdev.ipc_base);
102}
103
104/*
105 * IPC Write Buffer (Write Only):
106 * 16-byte buffer for sending data associated with IPC command to
107 * SCU. Size of the data is specified in the IPC_COMMAND_REG register
108 */
109static inline void ipc_data_writel(u32 data, u32 offset) /* Write ipc data */
110{
111	writel(data, ipcdev.ipc_base + 0x80 + offset);
112}
113
114/*
115 * Status Register (Read Only):
116 * Driver will read this register to get the ready/busy status of the IPC
117 * block and error status of the IPC command that was just processed by SCU
118 * Format:
119 * |rfu3(8)|error code(8)|initiator id(8)|cmd id(4)|rfu1(2)|error(1)|busy(1)|
120 */
121
122static inline u8 ipc_read_status(void)
123{
124	return __raw_readl(ipcdev.ipc_base + 0x04);
125}
126
127static inline u8 ipc_data_readb(u32 offset) /* Read ipc byte data */
128{
129	return readb(ipcdev.ipc_base + IPC_READ_BUFFER + offset);
130}
131
132static inline u32 ipc_data_readl(u32 offset) /* Read ipc u32 data */
133{
134	return readl(ipcdev.ipc_base + IPC_READ_BUFFER + offset);
135}
136
137static inline int busy_loop(void) /* Wait till scu status is busy */
138{
139	u32 status = 0;
140	u32 loop_count = 0;
141
142	status = ipc_read_status();
143	while (status & 1) {
144		udelay(1); /* scu processing time is in few u secods */
145		status = ipc_read_status();
146		loop_count++;
147		/* break if scu doesn't reset busy bit after huge retry */
148		if (loop_count > 100000) {
149			dev_err(&ipcdev.pdev->dev, "IPC timed out");
150			return -ETIMEDOUT;
151		}
152	}
153	if ((status >> 1) & 1)
154		return -EIO;
155
156	return 0;
157}
158
159/* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
160static int pwr_reg_rdwr(u16 *addr, u8 *data, u32 count, u32 op, u32 id)
161{
162	int nc;
163	u32 offset = 0;
164	int err;
165	u8 cbuf[IPC_WWBUF_SIZE] = { };
166	u32 *wbuf = (u32 *)&cbuf;
167
168	mutex_lock(&ipclock);
169
170	memset(cbuf, 0, sizeof(cbuf));
171
172	if (ipcdev.pdev == NULL) {
173		mutex_unlock(&ipclock);
174		return -ENODEV;
175	}
176
177	for (nc = 0; nc < count; nc++, offset += 2) {
178		cbuf[offset] = addr[nc];
179		cbuf[offset + 1] = addr[nc] >> 8;
180	}
181
182	if (id == IPC_CMD_PCNTRL_R) {
183		for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
184			ipc_data_writel(wbuf[nc], offset);
185		ipc_command((count*2) << 16 |  id << 12 | 0 << 8 | op);
186	} else if (id == IPC_CMD_PCNTRL_W) {
187		for (nc = 0; nc < count; nc++, offset += 1)
188			cbuf[offset] = data[nc];
189		for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
190			ipc_data_writel(wbuf[nc], offset);
191		ipc_command((count*3) << 16 |  id << 12 | 0 << 8 | op);
192	} else if (id == IPC_CMD_PCNTRL_M) {
193		cbuf[offset] = data[0];
194		cbuf[offset + 1] = data[1];
195		ipc_data_writel(wbuf[0], 0); /* Write wbuff */
196		ipc_command(4 << 16 |  id << 12 | 0 << 8 | op);
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
197	}
198
199	err = busy_loop();
200	if (id == IPC_CMD_PCNTRL_R) { /* Read rbuf */
201		/* Workaround: values are read as 0 without memcpy_fromio */
202		memcpy_fromio(cbuf, ipcdev.ipc_base + 0x90, 16);
203		for (nc = 0; nc < count; nc++)
204			data[nc] = ipc_data_readb(nc);
 
 
 
 
 
205	}
206	mutex_unlock(&ipclock);
207	return err;
208}
209
210/**
211 *	intel_scu_ipc_ioread8		-	read a word via the SCU
212 *	@addr: register on SCU
213 *	@data: return pointer for read byte
214 *
215 *	Read a single register. Returns 0 on success or an error code. All
216 *	locking between SCU accesses is handled for the caller.
217 *
218 *	This function may sleep.
219 */
220int intel_scu_ipc_ioread8(u16 addr, u8 *data)
221{
222	return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
223}
224EXPORT_SYMBOL(intel_scu_ipc_ioread8);
225
226/**
227 *	intel_scu_ipc_ioread16		-	read a word via the SCU
228 *	@addr: register on SCU
229 *	@data: return pointer for read word
230 *
231 *	Read a register pair. Returns 0 on success or an error code. All
232 *	locking between SCU accesses is handled for the caller.
233 *
234 *	This function may sleep.
235 */
236int intel_scu_ipc_ioread16(u16 addr, u16 *data)
237{
238	u16 x[2] = {addr, addr + 1 };
239	return pwr_reg_rdwr(x, (u8 *)data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
240}
241EXPORT_SYMBOL(intel_scu_ipc_ioread16);
242
243/**
244 *	intel_scu_ipc_ioread32		-	read a dword via the SCU
245 *	@addr: register on SCU
246 *	@data: return pointer for read dword
247 *
248 *	Read four registers. Returns 0 on success or an error code. All
249 *	locking between SCU accesses is handled for the caller.
250 *
251 *	This function may sleep.
252 */
253int intel_scu_ipc_ioread32(u16 addr, u32 *data)
254{
255	u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
256	return pwr_reg_rdwr(x, (u8 *)data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
257}
258EXPORT_SYMBOL(intel_scu_ipc_ioread32);
259
260/**
261 *	intel_scu_ipc_iowrite8		-	write a byte via the SCU
262 *	@addr: register on SCU
263 *	@data: byte to write
264 *
265 *	Write a single register. Returns 0 on success or an error code. All
266 *	locking between SCU accesses is handled for the caller.
267 *
268 *	This function may sleep.
269 */
270int intel_scu_ipc_iowrite8(u16 addr, u8 data)
271{
272	return pwr_reg_rdwr(&addr, &data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
273}
274EXPORT_SYMBOL(intel_scu_ipc_iowrite8);
275
276/**
277 *	intel_scu_ipc_iowrite16		-	write a word via the SCU
278 *	@addr: register on SCU
279 *	@data: word to write
280 *
281 *	Write two registers. Returns 0 on success or an error code. All
282 *	locking between SCU accesses is handled for the caller.
283 *
284 *	This function may sleep.
285 */
286int intel_scu_ipc_iowrite16(u16 addr, u16 data)
287{
288	u16 x[2] = {addr, addr + 1 };
289	return pwr_reg_rdwr(x, (u8 *)&data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
290}
291EXPORT_SYMBOL(intel_scu_ipc_iowrite16);
292
293/**
294 *	intel_scu_ipc_iowrite32		-	write a dword via the SCU
295 *	@addr: register on SCU
296 *	@data: dword to write
297 *
298 *	Write four registers. Returns 0 on success or an error code. All
299 *	locking between SCU accesses is handled for the caller.
300 *
301 *	This function may sleep.
302 */
303int intel_scu_ipc_iowrite32(u16 addr, u32 data)
304{
305	u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
306	return pwr_reg_rdwr(x, (u8 *)&data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
307}
308EXPORT_SYMBOL(intel_scu_ipc_iowrite32);
309
310/**
311 *	intel_scu_ipc_readvv		-	read a set of registers
312 *	@addr: register list
313 *	@data: bytes to return
314 *	@len: length of array
315 *
316 *	Read registers. Returns 0 on success or an error code. All
317 *	locking between SCU accesses is handled for the caller.
318 *
319 *	The largest array length permitted by the hardware is 5 items.
320 *
321 *	This function may sleep.
322 */
323int intel_scu_ipc_readv(u16 *addr, u8 *data, int len)
324{
325	return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
326}
327EXPORT_SYMBOL(intel_scu_ipc_readv);
328
329/**
330 *	intel_scu_ipc_writev		-	write a set of registers
331 *	@addr: register list
332 *	@data: bytes to write
333 *	@len: length of array
334 *
335 *	Write registers. Returns 0 on success or an error code. All
336 *	locking between SCU accesses is handled for the caller.
337 *
338 *	The largest array length permitted by the hardware is 5 items.
339 *
340 *	This function may sleep.
341 *
342 */
343int intel_scu_ipc_writev(u16 *addr, u8 *data, int len)
344{
345	return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
346}
347EXPORT_SYMBOL(intel_scu_ipc_writev);
348
349
350/**
351 *	intel_scu_ipc_update_register	-	r/m/w a register
352 *	@addr: register address
353 *	@bits: bits to update
354 *	@mask: mask of bits to update
355 *
356 *	Read-modify-write power control unit register. The first data argument
357 *	must be register value and second is mask value
358 *	mask is a bitmap that indicates which bits to update.
359 *	0 = masked. Don't modify this bit, 1 = modify this bit.
360 *	returns 0 on success or an error code.
361 *
362 *	This function may sleep. Locking between SCU accesses is handled
363 *	for the caller.
364 */
365int intel_scu_ipc_update_register(u16 addr, u8 bits, u8 mask)
366{
367	u8 data[2] = { bits, mask };
368	return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_M);
369}
370EXPORT_SYMBOL(intel_scu_ipc_update_register);
371
372/**
373 *	intel_scu_ipc_simple_command	-	send a simple command
374 *	@cmd: command
375 *	@sub: sub type
376 *
377 *	Issue a simple command to the SCU. Do not use this interface if
378 *	you must then access data as any data values may be overwritten
379 *	by another SCU access by the time this function returns.
380 *
381 *	This function may sleep. Locking for SCU accesses is handled for
382 *	the caller.
383 */
384int intel_scu_ipc_simple_command(int cmd, int sub)
385{
386	int err;
387
388	mutex_lock(&ipclock);
389	if (ipcdev.pdev == NULL) {
390		mutex_unlock(&ipclock);
391		return -ENODEV;
392	}
393	ipc_command(sub << 12 | cmd);
394	err = busy_loop();
395	mutex_unlock(&ipclock);
396	return err;
397}
398EXPORT_SYMBOL(intel_scu_ipc_simple_command);
399
400/**
401 *	intel_scu_ipc_command	-	command with data
402 *	@cmd: command
403 *	@sub: sub type
404 *	@in: input data
405 *	@inlen: input length in dwords
406 *	@out: output data
407 *	@outlein: output length in dwords
408 *
409 *	Issue a command to the SCU which involves data transfers. Do the
410 *	data copies under the lock but leave it for the caller to interpret
411 */
412
413int intel_scu_ipc_command(int cmd, int sub, u32 *in, int inlen,
414							u32 *out, int outlen)
415{
416	int i, err;
417
418	mutex_lock(&ipclock);
419	if (ipcdev.pdev == NULL) {
420		mutex_unlock(&ipclock);
421		return -ENODEV;
422	}
423
424	for (i = 0; i < inlen; i++)
425		ipc_data_writel(*in++, 4 * i);
426
427	ipc_command((inlen << 16) | (sub << 12) | cmd);
428	err = busy_loop();
429
430	for (i = 0; i < outlen; i++)
431		*out++ = ipc_data_readl(4 * i);
432
433	mutex_unlock(&ipclock);
434	return err;
435}
436EXPORT_SYMBOL(intel_scu_ipc_command);
437
438/*I2C commands */
439#define IPC_I2C_WRITE 1 /* I2C Write command */
440#define IPC_I2C_READ  2 /* I2C Read command */
441
442/**
443 *	intel_scu_ipc_i2c_cntrl		-	I2C read/write operations
444 *	@addr: I2C address + command bits
445 *	@data: data to read/write
446 *
447 *	Perform an an I2C read/write operation via the SCU. All locking is
448 *	handled for the caller. This function may sleep.
449 *
450 *	Returns an error code or 0 on success.
451 *
452 *	This has to be in the IPC driver for the locking.
453 */
454int intel_scu_ipc_i2c_cntrl(u32 addr, u32 *data)
455{
456	u32 cmd = 0;
457
458	mutex_lock(&ipclock);
459	if (ipcdev.pdev == NULL) {
460		mutex_unlock(&ipclock);
461		return -ENODEV;
462	}
463	cmd = (addr >> 24) & 0xFF;
464	if (cmd == IPC_I2C_READ) {
465		writel(addr, ipcdev.i2c_base + IPC_I2C_CNTRL_ADDR);
466		/* Write not getting updated without delay */
467		mdelay(1);
468		*data = readl(ipcdev.i2c_base + I2C_DATA_ADDR);
469	} else if (cmd == IPC_I2C_WRITE) {
470		writel(*data, ipcdev.i2c_base + I2C_DATA_ADDR);
471		mdelay(1);
472		writel(addr, ipcdev.i2c_base + IPC_I2C_CNTRL_ADDR);
473	} else {
474		dev_err(&ipcdev.pdev->dev,
475			"intel_scu_ipc: I2C INVALID_CMD = 0x%x\n", cmd);
476
477		mutex_unlock(&ipclock);
478		return -EIO;
479	}
480	mutex_unlock(&ipclock);
481	return 0;
482}
483EXPORT_SYMBOL(intel_scu_ipc_i2c_cntrl);
484
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
485/*
486 * Interrupt handler gets called when ioc bit of IPC_COMMAND_REG set to 1
487 * When ioc bit is set to 1, caller api must wait for interrupt handler called
488 * which in turn unlocks the caller api. Currently this is not used
489 *
490 * This is edge triggered so we need take no action to clear anything
491 */
492static irqreturn_t ioc(int irq, void *dev_id)
493{
494	return IRQ_HANDLED;
495}
496
497/**
498 *	ipc_probe	-	probe an Intel SCU IPC
499 *	@dev: the PCI device matching
500 *	@id: entry in the match table
501 *
502 *	Enable and install an intel SCU IPC. This appears in the PCI space
503 *	but uses some hard coded addresses as well.
504 */
505static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id)
506{
507	int err;
508	resource_size_t pci_resource;
509
510	if (ipcdev.pdev)		/* We support only one SCU */
511		return -EBUSY;
512
513	ipcdev.pdev = pci_dev_get(dev);
514
515	err = pci_enable_device(dev);
516	if (err)
517		return err;
518
519	err = pci_request_regions(dev, "intel_scu_ipc");
520	if (err)
521		return err;
522
523	pci_resource = pci_resource_start(dev, 0);
524	if (!pci_resource)
525		return -ENOMEM;
526
527	if (request_irq(dev->irq, ioc, 0, "intel_scu_ipc", &ipcdev))
528		return -EBUSY;
529
530	ipcdev.ipc_base = ioremap_nocache(IPC_BASE_ADDR, IPC_MAX_ADDR);
531	if (!ipcdev.ipc_base)
532		return -ENOMEM;
533
534	ipcdev.i2c_base = ioremap_nocache(IPC_I2C_BASE, IPC_I2C_MAX_ADDR);
535	if (!ipcdev.i2c_base) {
536		iounmap(ipcdev.ipc_base);
537		return -ENOMEM;
538	}
539
540	intel_scu_devices_create();
541
542	return 0;
543}
544
545/**
546 *	ipc_remove	-	remove a bound IPC device
547 *	@pdev: PCI device
548 *
549 *	In practice the SCU is not removable but this function is also
550 *	called for each device on a module unload or cleanup which is the
551 *	path that will get used.
552 *
553 *	Free up the mappings and release the PCI resources
554 */
555static void ipc_remove(struct pci_dev *pdev)
556{
557	free_irq(pdev->irq, &ipcdev);
558	pci_release_regions(pdev);
559	pci_dev_put(ipcdev.pdev);
560	iounmap(ipcdev.ipc_base);
561	iounmap(ipcdev.i2c_base);
562	ipcdev.pdev = NULL;
563	intel_scu_devices_destroy();
564}
565
566static DEFINE_PCI_DEVICE_TABLE(pci_ids) = {
 
567	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x082a)},
568	{ 0,}
569};
570MODULE_DEVICE_TABLE(pci, pci_ids);
571
572static struct pci_driver ipc_driver = {
573	.name = "intel_scu_ipc",
574	.id_table = pci_ids,
575	.probe = ipc_probe,
576	.remove = ipc_remove,
577};
578
579
580static int __init intel_scu_ipc_init(void)
581{
582	platform = mrst_identify_cpu();
583	if (platform == 0)
584		return -ENODEV;
585	return  pci_register_driver(&ipc_driver);
586}
587
588static void __exit intel_scu_ipc_exit(void)
589{
590	pci_unregister_driver(&ipc_driver);
591}
592
593MODULE_AUTHOR("Sreedhara DS <sreedhara.ds@intel.com>");
594MODULE_DESCRIPTION("Intel SCU IPC driver");
595MODULE_LICENSE("GPL");
596
597module_init(intel_scu_ipc_init);
598module_exit(intel_scu_ipc_exit);