xref: /linux/drivers/platform/x86/intel_scu_ipc.c (revision a234ca0faa65dcd5cc473915bd925130ebb7b74b)
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 runing 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 <asm/mrst.h>
27 #include <asm/intel_scu_ipc.h>
28 
29 /* IPC defines the following message types */
30 #define IPCMSG_WATCHDOG_TIMER 0xF8 /* Set Kernel Watchdog Threshold */
31 #define IPCMSG_BATTERY        0xEF /* Coulomb Counter Accumulator */
32 #define IPCMSG_FW_UPDATE      0xFE /* Firmware update */
33 #define IPCMSG_PCNTRL         0xFF /* Power controller unit read/write */
34 #define IPCMSG_FW_REVISION    0xF4 /* Get firmware revision */
35 
36 /* Command id associated with message IPCMSG_PCNTRL */
37 #define IPC_CMD_PCNTRL_W      0 /* Register write */
38 #define IPC_CMD_PCNTRL_R      1 /* Register read */
39 #define IPC_CMD_PCNTRL_M      2 /* Register read-modify-write */
40 
41 /*
42  * IPC register summary
43  *
44  * IPC register blocks are memory mapped at fixed address of 0xFF11C000
45  * To read or write information to the SCU, driver writes to IPC-1 memory
46  * mapped registers (base address 0xFF11C000). The following is the IPC
47  * mechanism
48  *
49  * 1. IA core cDMI interface claims this transaction and converts it to a
50  *    Transaction Layer Packet (TLP) message which is sent across the cDMI.
51  *
52  * 2. South Complex cDMI block receives this message and writes it to
53  *    the IPC-1 register block, causing an interrupt to the SCU
54  *
55  * 3. SCU firmware decodes this interrupt and IPC message and the appropriate
56  *    message handler is called within firmware.
57  */
58 
59 #define IPC_BASE_ADDR     0xFF11C000	/* IPC1 base register address */
60 #define IPC_MAX_ADDR      0x100		/* Maximum IPC regisers */
61 #define IPC_WWBUF_SIZE    20		/* IPC Write buffer Size */
62 #define IPC_RWBUF_SIZE    20		/* IPC Read buffer Size */
63 #define IPC_I2C_BASE      0xFF12B000	/* I2C control register base address */
64 #define IPC_I2C_MAX_ADDR  0x10		/* Maximum I2C regisers */
65 
66 static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id);
67 static void ipc_remove(struct pci_dev *pdev);
68 
69 struct intel_scu_ipc_dev {
70 	struct pci_dev *pdev;
71 	void __iomem *ipc_base;
72 	void __iomem *i2c_base;
73 };
74 
75 static struct intel_scu_ipc_dev  ipcdev; /* Only one for now */
76 
77 static int platform;		/* Platform type */
78 
79 /*
80  * IPC Read Buffer (Read Only):
81  * 16 byte buffer for receiving data from SCU, if IPC command
82  * processing results in response data
83  */
84 #define IPC_READ_BUFFER		0x90
85 
86 #define IPC_I2C_CNTRL_ADDR	0
87 #define I2C_DATA_ADDR		0x04
88 
89 static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
90 
91 /*
92  * Command Register (Write Only):
93  * A write to this register results in an interrupt to the SCU core processor
94  * Format:
95  * |rfu2(8) | size(8) | command id(4) | rfu1(3) | ioc(1) | command(8)|
96  */
97 static inline void ipc_command(u32 cmd) /* Send ipc command */
98 {
99 	writel(cmd, ipcdev.ipc_base);
100 }
101 
102 /*
103  * IPC Write Buffer (Write Only):
104  * 16-byte buffer for sending data associated with IPC command to
105  * SCU. Size of the data is specified in the IPC_COMMAND_REG register
106  */
107 static inline void ipc_data_writel(u32 data, u32 offset) /* Write ipc data */
108 {
109 	writel(data, ipcdev.ipc_base + 0x80 + offset);
110 }
111 
112 /*
113  * Status Register (Read Only):
114  * Driver will read this register to get the ready/busy status of the IPC
115  * block and error status of the IPC command that was just processed by SCU
116  * Format:
117  * |rfu3(8)|error code(8)|initiator id(8)|cmd id(4)|rfu1(2)|error(1)|busy(1)|
118  */
119 
120 static inline u8 ipc_read_status(void)
121 {
122 	return __raw_readl(ipcdev.ipc_base + 0x04);
123 }
124 
125 static inline u8 ipc_data_readb(u32 offset) /* Read ipc byte data */
126 {
127 	return readb(ipcdev.ipc_base + IPC_READ_BUFFER + offset);
128 }
129 
130 static inline u32 ipc_data_readl(u32 offset) /* Read ipc u32 data */
131 {
132 	return readl(ipcdev.ipc_base + IPC_READ_BUFFER + offset);
133 }
134 
135 static inline int busy_loop(void) /* Wait till scu status is busy */
136 {
137 	u32 status = 0;
138 	u32 loop_count = 0;
139 
140 	status = ipc_read_status();
141 	while (status & 1) {
142 		udelay(1); /* scu processing time is in few u secods */
143 		status = ipc_read_status();
144 		loop_count++;
145 		/* break if scu doesn't reset busy bit after huge retry */
146 		if (loop_count > 100000) {
147 			dev_err(&ipcdev.pdev->dev, "IPC timed out");
148 			return -ETIMEDOUT;
149 		}
150 	}
151 	if ((status >> 1) & 1)
152 		return -EIO;
153 
154 	return 0;
155 }
156 
157 /* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
158 static int pwr_reg_rdwr(u16 *addr, u8 *data, u32 count, u32 op, u32 id)
159 {
160 	int i, nc, bytes, d;
161 	u32 offset = 0;
162 	u32 err = 0;
163 	u8 cbuf[IPC_WWBUF_SIZE] = { };
164 	u32 *wbuf = (u32 *)&cbuf;
165 
166 	mutex_lock(&ipclock);
167 
168 	memset(cbuf, 0, sizeof(cbuf));
169 
170 	if (ipcdev.pdev == NULL) {
171 		mutex_unlock(&ipclock);
172 		return -ENODEV;
173 	}
174 
175 	if (platform != MRST_CPU_CHIP_PENWELL) {
176 		bytes = 0;
177 		d = 0;
178 		for (i = 0; i < count; i++) {
179 			cbuf[bytes++] = addr[i];
180 			cbuf[bytes++] = addr[i] >> 8;
181 			if (id != IPC_CMD_PCNTRL_R)
182 				cbuf[bytes++] = data[d++];
183 			if (id == IPC_CMD_PCNTRL_M)
184 				cbuf[bytes++] = data[d++];
185 		}
186 		for (i = 0; i < bytes; i += 4)
187 			ipc_data_writel(wbuf[i/4], i);
188 		ipc_command(bytes << 16 |  id << 12 | 0 << 8 | op);
189 	} else {
190 		for (nc = 0; nc < count; nc++, offset += 2) {
191 			cbuf[offset] = addr[nc];
192 			cbuf[offset + 1] = addr[nc] >> 8;
193 		}
194 
195 		if (id == IPC_CMD_PCNTRL_R) {
196 			for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
197 				ipc_data_writel(wbuf[nc], offset);
198 			ipc_command((count*2) << 16 |  id << 12 | 0 << 8 | op);
199 		} else if (id == IPC_CMD_PCNTRL_W) {
200 			for (nc = 0; nc < count; nc++, offset += 1)
201 				cbuf[offset] = data[nc];
202 			for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
203 				ipc_data_writel(wbuf[nc], offset);
204 			ipc_command((count*3) << 16 |  id << 12 | 0 << 8 | op);
205 		} else if (id == IPC_CMD_PCNTRL_M) {
206 			cbuf[offset] = data[0];
207 			cbuf[offset + 1] = data[1];
208 			ipc_data_writel(wbuf[0], 0); /* Write wbuff */
209 			ipc_command(4 << 16 |  id << 12 | 0 << 8 | op);
210 		}
211 	}
212 
213 	err = busy_loop();
214 	if (id == IPC_CMD_PCNTRL_R) { /* Read rbuf */
215 		/* Workaround: values are read as 0 without memcpy_fromio */
216 		memcpy_fromio(cbuf, ipcdev.ipc_base + 0x90, 16);
217 		if (platform != MRST_CPU_CHIP_PENWELL) {
218 			for (nc = 0, offset = 2; nc < count; nc++, offset += 3)
219 				data[nc] = ipc_data_readb(offset);
220 		} else {
221 			for (nc = 0; nc < count; nc++)
222 				data[nc] = ipc_data_readb(nc);
223 		}
224 	}
225 	mutex_unlock(&ipclock);
226 	return err;
227 }
228 
229 /**
230  *	intel_scu_ipc_ioread8		-	read a word via the SCU
231  *	@addr: register on SCU
232  *	@data: return pointer for read byte
233  *
234  *	Read a single register. Returns 0 on success or an error code. All
235  *	locking between SCU accesses is handled for the caller.
236  *
237  *	This function may sleep.
238  */
239 int intel_scu_ipc_ioread8(u16 addr, u8 *data)
240 {
241 	return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
242 }
243 EXPORT_SYMBOL(intel_scu_ipc_ioread8);
244 
245 /**
246  *	intel_scu_ipc_ioread16		-	read a word via the SCU
247  *	@addr: register on SCU
248  *	@data: return pointer for read word
249  *
250  *	Read a register pair. Returns 0 on success or an error code. All
251  *	locking between SCU accesses is handled for the caller.
252  *
253  *	This function may sleep.
254  */
255 int intel_scu_ipc_ioread16(u16 addr, u16 *data)
256 {
257 	u16 x[2] = {addr, addr + 1 };
258 	return pwr_reg_rdwr(x, (u8 *)data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
259 }
260 EXPORT_SYMBOL(intel_scu_ipc_ioread16);
261 
262 /**
263  *	intel_scu_ipc_ioread32		-	read a dword via the SCU
264  *	@addr: register on SCU
265  *	@data: return pointer for read dword
266  *
267  *	Read four registers. 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  */
272 int intel_scu_ipc_ioread32(u16 addr, u32 *data)
273 {
274 	u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
275 	return pwr_reg_rdwr(x, (u8 *)data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
276 }
277 EXPORT_SYMBOL(intel_scu_ipc_ioread32);
278 
279 /**
280  *	intel_scu_ipc_iowrite8		-	write a byte via the SCU
281  *	@addr: register on SCU
282  *	@data: byte to write
283  *
284  *	Write a single register. Returns 0 on success or an error code. All
285  *	locking between SCU accesses is handled for the caller.
286  *
287  *	This function may sleep.
288  */
289 int intel_scu_ipc_iowrite8(u16 addr, u8 data)
290 {
291 	return pwr_reg_rdwr(&addr, &data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
292 }
293 EXPORT_SYMBOL(intel_scu_ipc_iowrite8);
294 
295 /**
296  *	intel_scu_ipc_iowrite16		-	write a word via the SCU
297  *	@addr: register on SCU
298  *	@data: word to write
299  *
300  *	Write two 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  */
305 int intel_scu_ipc_iowrite16(u16 addr, u16 data)
306 {
307 	u16 x[2] = {addr, addr + 1 };
308 	return pwr_reg_rdwr(x, (u8 *)&data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
309 }
310 EXPORT_SYMBOL(intel_scu_ipc_iowrite16);
311 
312 /**
313  *	intel_scu_ipc_iowrite32		-	write a dword via the SCU
314  *	@addr: register on SCU
315  *	@data: dword to write
316  *
317  *	Write four registers. 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  */
322 int intel_scu_ipc_iowrite32(u16 addr, u32 data)
323 {
324 	u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
325 	return pwr_reg_rdwr(x, (u8 *)&data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
326 }
327 EXPORT_SYMBOL(intel_scu_ipc_iowrite32);
328 
329 /**
330  *	intel_scu_ipc_readvv		-	read a set of registers
331  *	@addr: register list
332  *	@data: bytes to return
333  *	@len: length of array
334  *
335  *	Read 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 int intel_scu_ipc_readv(u16 *addr, u8 *data, int len)
343 {
344 	return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
345 }
346 EXPORT_SYMBOL(intel_scu_ipc_readv);
347 
348 /**
349  *	intel_scu_ipc_writev		-	write a set of registers
350  *	@addr: register list
351  *	@data: bytes to write
352  *	@len: length of array
353  *
354  *	Write registers. Returns 0 on success or an error code. All
355  *	locking between SCU accesses is handled for the caller.
356  *
357  *	The largest array length permitted by the hardware is 5 items.
358  *
359  *	This function may sleep.
360  *
361  */
362 int intel_scu_ipc_writev(u16 *addr, u8 *data, int len)
363 {
364 	return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
365 }
366 EXPORT_SYMBOL(intel_scu_ipc_writev);
367 
368 
369 /**
370  *	intel_scu_ipc_update_register	-	r/m/w a register
371  *	@addr: register address
372  *	@bits: bits to update
373  *	@mask: mask of bits to update
374  *
375  *	Read-modify-write power control unit register. The first data argument
376  *	must be register value and second is mask value
377  *	mask is a bitmap that indicates which bits to update.
378  *	0 = masked. Don't modify this bit, 1 = modify this bit.
379  *	returns 0 on success or an error code.
380  *
381  *	This function may sleep. Locking between SCU accesses is handled
382  *	for the caller.
383  */
384 int intel_scu_ipc_update_register(u16 addr, u8 bits, u8 mask)
385 {
386 	u8 data[2] = { bits, mask };
387 	return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_M);
388 }
389 EXPORT_SYMBOL(intel_scu_ipc_update_register);
390 
391 /**
392  *	intel_scu_ipc_simple_command	-	send a simple command
393  *	@cmd: command
394  *	@sub: sub type
395  *
396  *	Issue a simple command to the SCU. Do not use this interface if
397  *	you must then access data as any data values may be overwritten
398  *	by another SCU access by the time this function returns.
399  *
400  *	This function may sleep. Locking for SCU accesses is handled for
401  *	the caller.
402  */
403 int intel_scu_ipc_simple_command(int cmd, int sub)
404 {
405 	u32 err = 0;
406 
407 	mutex_lock(&ipclock);
408 	if (ipcdev.pdev == NULL) {
409 		mutex_unlock(&ipclock);
410 		return -ENODEV;
411 	}
412 	ipc_command(sub << 12 | cmd);
413 	err = busy_loop();
414 	mutex_unlock(&ipclock);
415 	return err;
416 }
417 EXPORT_SYMBOL(intel_scu_ipc_simple_command);
418 
419 /**
420  *	intel_scu_ipc_command	-	command with data
421  *	@cmd: command
422  *	@sub: sub type
423  *	@in: input data
424  *	@inlen: input length in dwords
425  *	@out: output data
426  *	@outlein: output length in dwords
427  *
428  *	Issue a command to the SCU which involves data transfers. Do the
429  *	data copies under the lock but leave it for the caller to interpret
430  */
431 
432 int intel_scu_ipc_command(int cmd, int sub, u32 *in, int inlen,
433 							u32 *out, int outlen)
434 {
435 	u32 err = 0;
436 	int i = 0;
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 }
456 EXPORT_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  */
474 int 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(addr, 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 -1;
499 	}
500 	mutex_unlock(&ipclock);
501 	return 0;
502 }
503 EXPORT_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 
519 struct 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  */
534 int 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 
589 update_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 
634 update_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 -1;
644 }
645 EXPORT_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  */
654 static 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  */
667 static 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 	return 0;
702 }
703 
704 /**
705  *	ipc_remove	-	remove a bound IPC device
706  *	@pdev: PCI device
707  *
708  *	In practice the SCU is not removable but this function is also
709  *	called for each device on a module unload or cleanup which is the
710  *	path that will get used.
711  *
712  *	Free up the mappings and release the PCI resources
713  */
714 static void ipc_remove(struct pci_dev *pdev)
715 {
716 	free_irq(pdev->irq, &ipcdev);
717 	pci_release_regions(pdev);
718 	pci_dev_put(ipcdev.pdev);
719 	iounmap(ipcdev.ipc_base);
720 	iounmap(ipcdev.i2c_base);
721 	ipcdev.pdev = NULL;
722 }
723 
724 static const struct pci_device_id pci_ids[] = {
725 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x080e)},
726 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x082a)},
727 	{ 0,}
728 };
729 MODULE_DEVICE_TABLE(pci, pci_ids);
730 
731 static struct pci_driver ipc_driver = {
732 	.name = "intel_scu_ipc",
733 	.id_table = pci_ids,
734 	.probe = ipc_probe,
735 	.remove = ipc_remove,
736 };
737 
738 
739 static int __init intel_scu_ipc_init(void)
740 {
741 	platform = mrst_identify_cpu();
742 	if (platform == 0)
743 		return -ENODEV;
744 	return  pci_register_driver(&ipc_driver);
745 }
746 
747 static void __exit intel_scu_ipc_exit(void)
748 {
749 	pci_unregister_driver(&ipc_driver);
750 }
751 
752 MODULE_AUTHOR("Sreedhara DS <sreedhara.ds@intel.com>");
753 MODULE_DESCRIPTION("Intel SCU IPC driver");
754 MODULE_LICENSE("GPL");
755 
756 module_init(intel_scu_ipc_init);
757 module_exit(intel_scu_ipc_exit);
758