xref: /openbmc/linux/drivers/platform/x86/intel_scu_ipc.c (revision baa7eb025ab14f3cba2e35c0a8648f9c9f01d24f)
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 <linux/sfi.h>
27 #include <asm/mrst.h>
28 #include <asm/intel_scu_ipc.h>
29 #include <asm/mrst.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 
68 static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id);
69 static void ipc_remove(struct pci_dev *pdev);
70 
71 struct intel_scu_ipc_dev {
72 	struct pci_dev *pdev;
73 	void __iomem *ipc_base;
74 	void __iomem *i2c_base;
75 };
76 
77 static struct intel_scu_ipc_dev  ipcdev; /* Only one for now */
78 
79 static 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 
91 static 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  */
99 static 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  */
109 static 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 
122 static inline u8 ipc_read_status(void)
123 {
124 	return __raw_readl(ipcdev.ipc_base + 0x04);
125 }
126 
127 static inline u8 ipc_data_readb(u32 offset) /* Read ipc byte data */
128 {
129 	return readb(ipcdev.ipc_base + IPC_READ_BUFFER + offset);
130 }
131 
132 static inline u32 ipc_data_readl(u32 offset) /* Read ipc u32 data */
133 {
134 	return readl(ipcdev.ipc_base + IPC_READ_BUFFER + offset);
135 }
136 
137 static 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 */
160 static int pwr_reg_rdwr(u16 *addr, u8 *data, u32 count, u32 op, u32 id)
161 {
162 	int i, nc, bytes, d;
163 	u32 offset = 0;
164 	u32 err = 0;
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 	if (platform != MRST_CPU_CHIP_PENWELL) {
178 		bytes = 0;
179 		d = 0;
180 		for (i = 0; i < count; i++) {
181 			cbuf[bytes++] = addr[i];
182 			cbuf[bytes++] = addr[i] >> 8;
183 			if (id != IPC_CMD_PCNTRL_R)
184 				cbuf[bytes++] = data[d++];
185 			if (id == IPC_CMD_PCNTRL_M)
186 				cbuf[bytes++] = data[d++];
187 		}
188 		for (i = 0; i < bytes; i += 4)
189 			ipc_data_writel(wbuf[i/4], i);
190 		ipc_command(bytes << 16 |  id << 12 | 0 << 8 | op);
191 	} else {
192 		for (nc = 0; nc < count; nc++, offset += 2) {
193 			cbuf[offset] = addr[nc];
194 			cbuf[offset + 1] = addr[nc] >> 8;
195 		}
196 
197 		if (id == IPC_CMD_PCNTRL_R) {
198 			for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
199 				ipc_data_writel(wbuf[nc], offset);
200 			ipc_command((count*2) << 16 |  id << 12 | 0 << 8 | op);
201 		} else if (id == IPC_CMD_PCNTRL_W) {
202 			for (nc = 0; nc < count; nc++, offset += 1)
203 				cbuf[offset] = data[nc];
204 			for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
205 				ipc_data_writel(wbuf[nc], offset);
206 			ipc_command((count*3) << 16 |  id << 12 | 0 << 8 | op);
207 		} else if (id == IPC_CMD_PCNTRL_M) {
208 			cbuf[offset] = data[0];
209 			cbuf[offset + 1] = data[1];
210 			ipc_data_writel(wbuf[0], 0); /* Write wbuff */
211 			ipc_command(4 << 16 |  id << 12 | 0 << 8 | op);
212 		}
213 	}
214 
215 	err = busy_loop();
216 	if (id == IPC_CMD_PCNTRL_R) { /* Read rbuf */
217 		/* Workaround: values are read as 0 without memcpy_fromio */
218 		memcpy_fromio(cbuf, ipcdev.ipc_base + 0x90, 16);
219 		if (platform != MRST_CPU_CHIP_PENWELL) {
220 			for (nc = 0, offset = 2; nc < count; nc++, offset += 3)
221 				data[nc] = ipc_data_readb(offset);
222 		} else {
223 			for (nc = 0; nc < count; nc++)
224 				data[nc] = ipc_data_readb(nc);
225 		}
226 	}
227 	mutex_unlock(&ipclock);
228 	return err;
229 }
230 
231 /**
232  *	intel_scu_ipc_ioread8		-	read a word via the SCU
233  *	@addr: register on SCU
234  *	@data: return pointer for read byte
235  *
236  *	Read a single register. Returns 0 on success or an error code. All
237  *	locking between SCU accesses is handled for the caller.
238  *
239  *	This function may sleep.
240  */
241 int intel_scu_ipc_ioread8(u16 addr, u8 *data)
242 {
243 	return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
244 }
245 EXPORT_SYMBOL(intel_scu_ipc_ioread8);
246 
247 /**
248  *	intel_scu_ipc_ioread16		-	read a word via the SCU
249  *	@addr: register on SCU
250  *	@data: return pointer for read word
251  *
252  *	Read a register pair. Returns 0 on success or an error code. All
253  *	locking between SCU accesses is handled for the caller.
254  *
255  *	This function may sleep.
256  */
257 int intel_scu_ipc_ioread16(u16 addr, u16 *data)
258 {
259 	u16 x[2] = {addr, addr + 1 };
260 	return pwr_reg_rdwr(x, (u8 *)data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
261 }
262 EXPORT_SYMBOL(intel_scu_ipc_ioread16);
263 
264 /**
265  *	intel_scu_ipc_ioread32		-	read a dword via the SCU
266  *	@addr: register on SCU
267  *	@data: return pointer for read dword
268  *
269  *	Read four registers. Returns 0 on success or an error code. All
270  *	locking between SCU accesses is handled for the caller.
271  *
272  *	This function may sleep.
273  */
274 int intel_scu_ipc_ioread32(u16 addr, u32 *data)
275 {
276 	u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
277 	return pwr_reg_rdwr(x, (u8 *)data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
278 }
279 EXPORT_SYMBOL(intel_scu_ipc_ioread32);
280 
281 /**
282  *	intel_scu_ipc_iowrite8		-	write a byte via the SCU
283  *	@addr: register on SCU
284  *	@data: byte to write
285  *
286  *	Write a single register. Returns 0 on success or an error code. All
287  *	locking between SCU accesses is handled for the caller.
288  *
289  *	This function may sleep.
290  */
291 int intel_scu_ipc_iowrite8(u16 addr, u8 data)
292 {
293 	return pwr_reg_rdwr(&addr, &data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
294 }
295 EXPORT_SYMBOL(intel_scu_ipc_iowrite8);
296 
297 /**
298  *	intel_scu_ipc_iowrite16		-	write a word via the SCU
299  *	@addr: register on SCU
300  *	@data: word to write
301  *
302  *	Write two registers. Returns 0 on success or an error code. All
303  *	locking between SCU accesses is handled for the caller.
304  *
305  *	This function may sleep.
306  */
307 int intel_scu_ipc_iowrite16(u16 addr, u16 data)
308 {
309 	u16 x[2] = {addr, addr + 1 };
310 	return pwr_reg_rdwr(x, (u8 *)&data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
311 }
312 EXPORT_SYMBOL(intel_scu_ipc_iowrite16);
313 
314 /**
315  *	intel_scu_ipc_iowrite32		-	write a dword via the SCU
316  *	@addr: register on SCU
317  *	@data: dword to write
318  *
319  *	Write four registers. Returns 0 on success or an error code. All
320  *	locking between SCU accesses is handled for the caller.
321  *
322  *	This function may sleep.
323  */
324 int intel_scu_ipc_iowrite32(u16 addr, u32 data)
325 {
326 	u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
327 	return pwr_reg_rdwr(x, (u8 *)&data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
328 }
329 EXPORT_SYMBOL(intel_scu_ipc_iowrite32);
330 
331 /**
332  *	intel_scu_ipc_readvv		-	read a set of registers
333  *	@addr: register list
334  *	@data: bytes to return
335  *	@len: length of array
336  *
337  *	Read registers. Returns 0 on success or an error code. All
338  *	locking between SCU accesses is handled for the caller.
339  *
340  *	The largest array length permitted by the hardware is 5 items.
341  *
342  *	This function may sleep.
343  */
344 int intel_scu_ipc_readv(u16 *addr, u8 *data, int len)
345 {
346 	return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
347 }
348 EXPORT_SYMBOL(intel_scu_ipc_readv);
349 
350 /**
351  *	intel_scu_ipc_writev		-	write a set of registers
352  *	@addr: register list
353  *	@data: bytes to write
354  *	@len: length of array
355  *
356  *	Write registers. Returns 0 on success or an error code. All
357  *	locking between SCU accesses is handled for the caller.
358  *
359  *	The largest array length permitted by the hardware is 5 items.
360  *
361  *	This function may sleep.
362  *
363  */
364 int intel_scu_ipc_writev(u16 *addr, u8 *data, int len)
365 {
366 	return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
367 }
368 EXPORT_SYMBOL(intel_scu_ipc_writev);
369 
370 
371 /**
372  *	intel_scu_ipc_update_register	-	r/m/w a register
373  *	@addr: register address
374  *	@bits: bits to update
375  *	@mask: mask of bits to update
376  *
377  *	Read-modify-write power control unit register. The first data argument
378  *	must be register value and second is mask value
379  *	mask is a bitmap that indicates which bits to update.
380  *	0 = masked. Don't modify this bit, 1 = modify this bit.
381  *	returns 0 on success or an error code.
382  *
383  *	This function may sleep. Locking between SCU accesses is handled
384  *	for the caller.
385  */
386 int intel_scu_ipc_update_register(u16 addr, u8 bits, u8 mask)
387 {
388 	u8 data[2] = { bits, mask };
389 	return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_M);
390 }
391 EXPORT_SYMBOL(intel_scu_ipc_update_register);
392 
393 /**
394  *	intel_scu_ipc_simple_command	-	send a simple command
395  *	@cmd: command
396  *	@sub: sub type
397  *
398  *	Issue a simple command to the SCU. Do not use this interface if
399  *	you must then access data as any data values may be overwritten
400  *	by another SCU access by the time this function returns.
401  *
402  *	This function may sleep. Locking for SCU accesses is handled for
403  *	the caller.
404  */
405 int intel_scu_ipc_simple_command(int cmd, int sub)
406 {
407 	u32 err = 0;
408 
409 	mutex_lock(&ipclock);
410 	if (ipcdev.pdev == NULL) {
411 		mutex_unlock(&ipclock);
412 		return -ENODEV;
413 	}
414 	ipc_command(sub << 12 | cmd);
415 	err = busy_loop();
416 	mutex_unlock(&ipclock);
417 	return err;
418 }
419 EXPORT_SYMBOL(intel_scu_ipc_simple_command);
420 
421 /**
422  *	intel_scu_ipc_command	-	command with data
423  *	@cmd: command
424  *	@sub: sub type
425  *	@in: input data
426  *	@inlen: input length in dwords
427  *	@out: output data
428  *	@outlein: output length in dwords
429  *
430  *	Issue a command to the SCU which involves data transfers. Do the
431  *	data copies under the lock but leave it for the caller to interpret
432  */
433 
434 int intel_scu_ipc_command(int cmd, int sub, u32 *in, int inlen,
435 							u32 *out, int outlen)
436 {
437 	u32 err = 0;
438 	int i = 0;
439 
440 	mutex_lock(&ipclock);
441 	if (ipcdev.pdev == NULL) {
442 		mutex_unlock(&ipclock);
443 		return -ENODEV;
444 	}
445 
446 	for (i = 0; i < inlen; i++)
447 		ipc_data_writel(*in++, 4 * i);
448 
449 	ipc_command((inlen << 16) | (sub << 12) | cmd);
450 	err = busy_loop();
451 
452 	for (i = 0; i < outlen; i++)
453 		*out++ = ipc_data_readl(4 * i);
454 
455 	mutex_unlock(&ipclock);
456 	return err;
457 }
458 EXPORT_SYMBOL(intel_scu_ipc_command);
459 
460 /*I2C commands */
461 #define IPC_I2C_WRITE 1 /* I2C Write command */
462 #define IPC_I2C_READ  2 /* I2C Read command */
463 
464 /**
465  *	intel_scu_ipc_i2c_cntrl		-	I2C read/write operations
466  *	@addr: I2C address + command bits
467  *	@data: data to read/write
468  *
469  *	Perform an an I2C read/write operation via the SCU. All locking is
470  *	handled for the caller. This function may sleep.
471  *
472  *	Returns an error code or 0 on success.
473  *
474  *	This has to be in the IPC driver for the locking.
475  */
476 int intel_scu_ipc_i2c_cntrl(u32 addr, u32 *data)
477 {
478 	u32 cmd = 0;
479 
480 	mutex_lock(&ipclock);
481 	if (ipcdev.pdev == NULL) {
482 		mutex_unlock(&ipclock);
483 		return -ENODEV;
484 	}
485 	cmd = (addr >> 24) & 0xFF;
486 	if (cmd == IPC_I2C_READ) {
487 		writel(addr, ipcdev.i2c_base + IPC_I2C_CNTRL_ADDR);
488 		/* Write not getting updated without delay */
489 		mdelay(1);
490 		*data = readl(ipcdev.i2c_base + I2C_DATA_ADDR);
491 	} else if (cmd == IPC_I2C_WRITE) {
492 		writel(*data, ipcdev.i2c_base + I2C_DATA_ADDR);
493 		mdelay(1);
494 		writel(addr, ipcdev.i2c_base + IPC_I2C_CNTRL_ADDR);
495 	} else {
496 		dev_err(&ipcdev.pdev->dev,
497 			"intel_scu_ipc: I2C INVALID_CMD = 0x%x\n", cmd);
498 
499 		mutex_unlock(&ipclock);
500 		return -1;
501 	}
502 	mutex_unlock(&ipclock);
503 	return 0;
504 }
505 EXPORT_SYMBOL(intel_scu_ipc_i2c_cntrl);
506 
507 #define IPC_FW_LOAD_ADDR 0xFFFC0000 /* Storage location for FW image */
508 #define IPC_FW_UPDATE_MBOX_ADDR 0xFFFFDFF4 /* Mailbox between ipc and scu */
509 #define IPC_MAX_FW_SIZE 262144 /* 256K storage size for loading the FW image */
510 #define IPC_FW_MIP_HEADER_SIZE 2048 /* Firmware MIP header size */
511 /* IPC inform SCU to get ready for update process */
512 #define IPC_CMD_FW_UPDATE_READY  0x10FE
513 /* IPC inform SCU to go for update process */
514 #define IPC_CMD_FW_UPDATE_GO     0x20FE
515 /* Status code for fw update */
516 #define IPC_FW_UPDATE_SUCCESS	0x444f4e45 /* Status code 'DONE' */
517 #define IPC_FW_UPDATE_BADN	0x4241444E /* Status code 'BADN' */
518 #define IPC_FW_TXHIGH		0x54784849 /* Status code 'IPC_FW_TXHIGH' */
519 #define IPC_FW_TXLOW		0x54784c4f /* Status code 'IPC_FW_TXLOW' */
520 
521 struct fw_update_mailbox {
522 	u32    status;
523 	u32    scu_flag;
524 	u32    driver_flag;
525 };
526 
527 
528 /**
529  *	intel_scu_ipc_fw_update	-	 Firmware update utility
530  *	@buffer: firmware buffer
531  *	@length: size of firmware buffer
532  *
533  *	This function provides an interface to load the firmware into
534  *	the SCU. Returns 0 on success or -1 on failure
535  */
536 int intel_scu_ipc_fw_update(u8 *buffer, u32 length)
537 {
538 	void __iomem *fw_update_base;
539 	struct fw_update_mailbox __iomem *mailbox = NULL;
540 	int retry_cnt = 0;
541 	u32 status;
542 
543 	mutex_lock(&ipclock);
544 	fw_update_base = ioremap_nocache(IPC_FW_LOAD_ADDR, (128*1024));
545 	if (fw_update_base == NULL) {
546 		mutex_unlock(&ipclock);
547 		return -ENOMEM;
548 	}
549 	mailbox = ioremap_nocache(IPC_FW_UPDATE_MBOX_ADDR,
550 					sizeof(struct fw_update_mailbox));
551 	if (mailbox == NULL) {
552 		iounmap(fw_update_base);
553 		mutex_unlock(&ipclock);
554 		return -ENOMEM;
555 	}
556 
557 	ipc_command(IPC_CMD_FW_UPDATE_READY);
558 
559 	/* Intitialize mailbox */
560 	writel(0, &mailbox->status);
561 	writel(0, &mailbox->scu_flag);
562 	writel(0, &mailbox->driver_flag);
563 
564 	/* Driver copies the 2KB MIP header to SRAM at 0xFFFC0000*/
565 	memcpy_toio(fw_update_base, buffer, 0x800);
566 
567 	/* Driver sends "FW Update" IPC command (CMD_ID 0xFE; MSG_ID 0x02).
568 	* Upon receiving this command, SCU will write the 2K MIP header
569 	* from 0xFFFC0000 into NAND.
570 	* SCU will write a status code into the Mailbox, and then set scu_flag.
571 	*/
572 
573 	ipc_command(IPC_CMD_FW_UPDATE_GO);
574 
575 	/*Driver stalls until scu_flag is set */
576 	while (readl(&mailbox->scu_flag) != 1) {
577 		rmb();
578 		mdelay(1);
579 	}
580 
581 	/* Driver checks Mailbox status.
582 	 * If the status is 'BADN', then abort (bad NAND).
583 	 * If the status is 'IPC_FW_TXLOW', then continue.
584 	 */
585 	while (readl(&mailbox->status) != IPC_FW_TXLOW) {
586 		rmb();
587 		mdelay(10);
588 	}
589 	mdelay(10);
590 
591 update_retry:
592 	if (retry_cnt > 5)
593 		goto update_end;
594 
595 	if (readl(&mailbox->status) != IPC_FW_TXLOW)
596 		goto update_end;
597 	buffer = buffer + 0x800;
598 	memcpy_toio(fw_update_base, buffer, 0x20000);
599 	writel(1, &mailbox->driver_flag);
600 	while (readl(&mailbox->scu_flag) == 1) {
601 		rmb();
602 		mdelay(1);
603 	}
604 
605 	/* check for 'BADN' */
606 	if (readl(&mailbox->status) == IPC_FW_UPDATE_BADN)
607 		goto update_end;
608 
609 	while (readl(&mailbox->status) != IPC_FW_TXHIGH) {
610 		rmb();
611 		mdelay(10);
612 	}
613 	mdelay(10);
614 
615 	if (readl(&mailbox->status) != IPC_FW_TXHIGH)
616 		goto update_end;
617 
618 	buffer = buffer + 0x20000;
619 	memcpy_toio(fw_update_base, buffer, 0x20000);
620 	writel(0, &mailbox->driver_flag);
621 
622 	while (mailbox->scu_flag == 0) {
623 		rmb();
624 		mdelay(1);
625 	}
626 
627 	/* check for 'BADN' */
628 	if (readl(&mailbox->status) == IPC_FW_UPDATE_BADN)
629 		goto update_end;
630 
631 	if (readl(&mailbox->status) == IPC_FW_TXLOW) {
632 		++retry_cnt;
633 		goto update_retry;
634 	}
635 
636 update_end:
637 	status = readl(&mailbox->status);
638 
639 	iounmap(fw_update_base);
640 	iounmap(mailbox);
641 	mutex_unlock(&ipclock);
642 
643 	if (status == IPC_FW_UPDATE_SUCCESS)
644 		return 0;
645 	return -1;
646 }
647 EXPORT_SYMBOL(intel_scu_ipc_fw_update);
648 
649 /*
650  * Interrupt handler gets called when ioc bit of IPC_COMMAND_REG set to 1
651  * When ioc bit is set to 1, caller api must wait for interrupt handler called
652  * which in turn unlocks the caller api. Currently this is not used
653  *
654  * This is edge triggered so we need take no action to clear anything
655  */
656 static irqreturn_t ioc(int irq, void *dev_id)
657 {
658 	return IRQ_HANDLED;
659 }
660 
661 /**
662  *	ipc_probe	-	probe an Intel SCU IPC
663  *	@dev: the PCI device matching
664  *	@id: entry in the match table
665  *
666  *	Enable and install an intel SCU IPC. This appears in the PCI space
667  *	but uses some hard coded addresses as well.
668  */
669 static int ipc_probe(struct pci_dev *dev, const struct pci_device_id *id)
670 {
671 	int err;
672 	resource_size_t pci_resource;
673 
674 	if (ipcdev.pdev)		/* We support only one SCU */
675 		return -EBUSY;
676 
677 	ipcdev.pdev = pci_dev_get(dev);
678 
679 	err = pci_enable_device(dev);
680 	if (err)
681 		return err;
682 
683 	err = pci_request_regions(dev, "intel_scu_ipc");
684 	if (err)
685 		return err;
686 
687 	pci_resource = pci_resource_start(dev, 0);
688 	if (!pci_resource)
689 		return -ENOMEM;
690 
691 	if (request_irq(dev->irq, ioc, 0, "intel_scu_ipc", &ipcdev))
692 		return -EBUSY;
693 
694 	ipcdev.ipc_base = ioremap_nocache(IPC_BASE_ADDR, IPC_MAX_ADDR);
695 	if (!ipcdev.ipc_base)
696 		return -ENOMEM;
697 
698 	ipcdev.i2c_base = ioremap_nocache(IPC_I2C_BASE, IPC_I2C_MAX_ADDR);
699 	if (!ipcdev.i2c_base) {
700 		iounmap(ipcdev.ipc_base);
701 		return -ENOMEM;
702 	}
703 
704 	intel_scu_devices_create();
705 
706 	return 0;
707 }
708 
709 /**
710  *	ipc_remove	-	remove a bound IPC device
711  *	@pdev: PCI device
712  *
713  *	In practice the SCU is not removable but this function is also
714  *	called for each device on a module unload or cleanup which is the
715  *	path that will get used.
716  *
717  *	Free up the mappings and release the PCI resources
718  */
719 static void ipc_remove(struct pci_dev *pdev)
720 {
721 	free_irq(pdev->irq, &ipcdev);
722 	pci_release_regions(pdev);
723 	pci_dev_put(ipcdev.pdev);
724 	iounmap(ipcdev.ipc_base);
725 	iounmap(ipcdev.i2c_base);
726 	ipcdev.pdev = NULL;
727 	intel_scu_devices_destroy();
728 }
729 
730 static const struct pci_device_id pci_ids[] = {
731 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x080e)},
732 	{PCI_DEVICE(PCI_VENDOR_ID_INTEL, 0x082a)},
733 	{ 0,}
734 };
735 MODULE_DEVICE_TABLE(pci, pci_ids);
736 
737 static struct pci_driver ipc_driver = {
738 	.name = "intel_scu_ipc",
739 	.id_table = pci_ids,
740 	.probe = ipc_probe,
741 	.remove = ipc_remove,
742 };
743 
744 
745 static int __init intel_scu_ipc_init(void)
746 {
747 	platform = mrst_identify_cpu();
748 	if (platform == 0)
749 		return -ENODEV;
750 	return  pci_register_driver(&ipc_driver);
751 }
752 
753 static void __exit intel_scu_ipc_exit(void)
754 {
755 	pci_unregister_driver(&ipc_driver);
756 }
757 
758 MODULE_AUTHOR("Sreedhara DS <sreedhara.ds@intel.com>");
759 MODULE_DESCRIPTION("Intel SCU IPC driver");
760 MODULE_LICENSE("GPL");
761 
762 module_init(intel_scu_ipc_init);
763 module_exit(intel_scu_ipc_exit);
764