Loading...
1/*
2 * intel_scu_ipc.c: Driver for the Intel SCU IPC mechanism
3 *
4 * (C) Copyright 2008-2010,2015 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 <asm/intel-mid.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 PCI BAR 0.
46 * To read or write information to the SCU, driver writes to IPC-1 memory
47 * mapped registers. The following is the IPC 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_WWBUF_SIZE 20 /* IPC Write buffer Size */
60#define IPC_RWBUF_SIZE 20 /* IPC Read buffer Size */
61#define IPC_IOC 0x100 /* IPC command register IOC bit */
62
63#define PCI_DEVICE_ID_LINCROFT 0x082a
64#define PCI_DEVICE_ID_PENWELL 0x080e
65#define PCI_DEVICE_ID_CLOVERVIEW 0x08ea
66#define PCI_DEVICE_ID_TANGIER 0x11a0
67
68/* intel scu ipc driver data */
69struct intel_scu_ipc_pdata_t {
70 u32 i2c_base;
71 u32 i2c_len;
72 u8 irq_mode;
73};
74
75static struct intel_scu_ipc_pdata_t intel_scu_ipc_lincroft_pdata = {
76 .i2c_base = 0xff12b000,
77 .i2c_len = 0x10,
78 .irq_mode = 0,
79};
80
81/* Penwell and Cloverview */
82static struct intel_scu_ipc_pdata_t intel_scu_ipc_penwell_pdata = {
83 .i2c_base = 0xff12b000,
84 .i2c_len = 0x10,
85 .irq_mode = 1,
86};
87
88static struct intel_scu_ipc_pdata_t intel_scu_ipc_tangier_pdata = {
89 .i2c_base = 0xff00d000,
90 .i2c_len = 0x10,
91 .irq_mode = 0,
92};
93
94struct intel_scu_ipc_dev {
95 struct device *dev;
96 void __iomem *ipc_base;
97 void __iomem *i2c_base;
98 struct completion cmd_complete;
99 u8 irq_mode;
100};
101
102static struct intel_scu_ipc_dev ipcdev; /* Only one for now */
103
104/*
105 * IPC Read Buffer (Read Only):
106 * 16 byte buffer for receiving data from SCU, if IPC command
107 * processing results in response data
108 */
109#define IPC_READ_BUFFER 0x90
110
111#define IPC_I2C_CNTRL_ADDR 0
112#define I2C_DATA_ADDR 0x04
113
114static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
115
116/*
117 * Send ipc command
118 * Command Register (Write Only):
119 * A write to this register results in an interrupt to the SCU core processor
120 * Format:
121 * |rfu2(8) | size(8) | command id(4) | rfu1(3) | ioc(1) | command(8)|
122 */
123static inline void ipc_command(struct intel_scu_ipc_dev *scu, u32 cmd)
124{
125 if (scu->irq_mode) {
126 reinit_completion(&scu->cmd_complete);
127 writel(cmd | IPC_IOC, scu->ipc_base);
128 }
129 writel(cmd, scu->ipc_base);
130}
131
132/*
133 * Write ipc data
134 * IPC Write Buffer (Write Only):
135 * 16-byte buffer for sending data associated with IPC command to
136 * SCU. Size of the data is specified in the IPC_COMMAND_REG register
137 */
138static inline void ipc_data_writel(struct intel_scu_ipc_dev *scu, u32 data, u32 offset)
139{
140 writel(data, scu->ipc_base + 0x80 + offset);
141}
142
143/*
144 * Status Register (Read Only):
145 * Driver will read this register to get the ready/busy status of the IPC
146 * block and error status of the IPC command that was just processed by SCU
147 * Format:
148 * |rfu3(8)|error code(8)|initiator id(8)|cmd id(4)|rfu1(2)|error(1)|busy(1)|
149 */
150static inline u8 ipc_read_status(struct intel_scu_ipc_dev *scu)
151{
152 return __raw_readl(scu->ipc_base + 0x04);
153}
154
155/* Read ipc byte data */
156static inline u8 ipc_data_readb(struct intel_scu_ipc_dev *scu, u32 offset)
157{
158 return readb(scu->ipc_base + IPC_READ_BUFFER + offset);
159}
160
161/* Read ipc u32 data */
162static inline u32 ipc_data_readl(struct intel_scu_ipc_dev *scu, u32 offset)
163{
164 return readl(scu->ipc_base + IPC_READ_BUFFER + offset);
165}
166
167/* Wait till scu status is busy */
168static inline int busy_loop(struct intel_scu_ipc_dev *scu)
169{
170 u32 status = ipc_read_status(scu);
171 u32 loop_count = 100000;
172
173 /* break if scu doesn't reset busy bit after huge retry */
174 while ((status & BIT(0)) && --loop_count) {
175 udelay(1); /* scu processing time is in few u secods */
176 status = ipc_read_status(scu);
177 }
178
179 if (status & BIT(0)) {
180 dev_err(scu->dev, "IPC timed out");
181 return -ETIMEDOUT;
182 }
183
184 if (status & BIT(1))
185 return -EIO;
186
187 return 0;
188}
189
190/* Wait till ipc ioc interrupt is received or timeout in 3 HZ */
191static inline int ipc_wait_for_interrupt(struct intel_scu_ipc_dev *scu)
192{
193 int status;
194
195 if (!wait_for_completion_timeout(&scu->cmd_complete, 3 * HZ)) {
196 dev_err(scu->dev, "IPC timed out\n");
197 return -ETIMEDOUT;
198 }
199
200 status = ipc_read_status(scu);
201 if (status & BIT(1))
202 return -EIO;
203
204 return 0;
205}
206
207static int intel_scu_ipc_check_status(struct intel_scu_ipc_dev *scu)
208{
209 return scu->irq_mode ? ipc_wait_for_interrupt(scu) : busy_loop(scu);
210}
211
212/* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
213static int pwr_reg_rdwr(u16 *addr, u8 *data, u32 count, u32 op, u32 id)
214{
215 struct intel_scu_ipc_dev *scu = &ipcdev;
216 int nc;
217 u32 offset = 0;
218 int err;
219 u8 cbuf[IPC_WWBUF_SIZE];
220 u32 *wbuf = (u32 *)&cbuf;
221
222 memset(cbuf, 0, sizeof(cbuf));
223
224 mutex_lock(&ipclock);
225
226 if (scu->dev == NULL) {
227 mutex_unlock(&ipclock);
228 return -ENODEV;
229 }
230
231 for (nc = 0; nc < count; nc++, offset += 2) {
232 cbuf[offset] = addr[nc];
233 cbuf[offset + 1] = addr[nc] >> 8;
234 }
235
236 if (id == IPC_CMD_PCNTRL_R) {
237 for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
238 ipc_data_writel(scu, wbuf[nc], offset);
239 ipc_command(scu, (count * 2) << 16 | id << 12 | 0 << 8 | op);
240 } else if (id == IPC_CMD_PCNTRL_W) {
241 for (nc = 0; nc < count; nc++, offset += 1)
242 cbuf[offset] = data[nc];
243 for (nc = 0, offset = 0; nc < count; nc++, offset += 4)
244 ipc_data_writel(scu, wbuf[nc], offset);
245 ipc_command(scu, (count * 3) << 16 | id << 12 | 0 << 8 | op);
246 } else if (id == IPC_CMD_PCNTRL_M) {
247 cbuf[offset] = data[0];
248 cbuf[offset + 1] = data[1];
249 ipc_data_writel(scu, wbuf[0], 0); /* Write wbuff */
250 ipc_command(scu, 4 << 16 | id << 12 | 0 << 8 | op);
251 }
252
253 err = intel_scu_ipc_check_status(scu);
254 if (!err && id == IPC_CMD_PCNTRL_R) { /* Read rbuf */
255 /* Workaround: values are read as 0 without memcpy_fromio */
256 memcpy_fromio(cbuf, scu->ipc_base + 0x90, 16);
257 for (nc = 0; nc < count; nc++)
258 data[nc] = ipc_data_readb(scu, nc);
259 }
260 mutex_unlock(&ipclock);
261 return err;
262}
263
264/**
265 * intel_scu_ipc_ioread8 - read a word via the SCU
266 * @addr: register on SCU
267 * @data: return pointer for read byte
268 *
269 * Read a single register. 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 */
274int intel_scu_ipc_ioread8(u16 addr, u8 *data)
275{
276 return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
277}
278EXPORT_SYMBOL(intel_scu_ipc_ioread8);
279
280/**
281 * intel_scu_ipc_ioread16 - read a word via the SCU
282 * @addr: register on SCU
283 * @data: return pointer for read word
284 *
285 * Read a register pair. 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_ioread16(u16 addr, u16 *data)
291{
292 u16 x[2] = {addr, addr + 1};
293 return pwr_reg_rdwr(x, (u8 *)data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
294}
295EXPORT_SYMBOL(intel_scu_ipc_ioread16);
296
297/**
298 * intel_scu_ipc_ioread32 - read a dword via the SCU
299 * @addr: register on SCU
300 * @data: return pointer for read dword
301 *
302 * Read four 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 */
307int intel_scu_ipc_ioread32(u16 addr, u32 *data)
308{
309 u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
310 return pwr_reg_rdwr(x, (u8 *)data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
311}
312EXPORT_SYMBOL(intel_scu_ipc_ioread32);
313
314/**
315 * intel_scu_ipc_iowrite8 - write a byte via the SCU
316 * @addr: register on SCU
317 * @data: byte to write
318 *
319 * Write a single register. 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 */
324int intel_scu_ipc_iowrite8(u16 addr, u8 data)
325{
326 return pwr_reg_rdwr(&addr, &data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
327}
328EXPORT_SYMBOL(intel_scu_ipc_iowrite8);
329
330/**
331 * intel_scu_ipc_iowrite16 - write a word via the SCU
332 * @addr: register on SCU
333 * @data: word to write
334 *
335 * Write two registers. Returns 0 on success or an error code. All
336 * locking between SCU accesses is handled for the caller.
337 *
338 * This function may sleep.
339 */
340int intel_scu_ipc_iowrite16(u16 addr, u16 data)
341{
342 u16 x[2] = {addr, addr + 1};
343 return pwr_reg_rdwr(x, (u8 *)&data, 2, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
344}
345EXPORT_SYMBOL(intel_scu_ipc_iowrite16);
346
347/**
348 * intel_scu_ipc_iowrite32 - write a dword via the SCU
349 * @addr: register on SCU
350 * @data: dword to write
351 *
352 * Write four registers. Returns 0 on success or an error code. All
353 * locking between SCU accesses is handled for the caller.
354 *
355 * This function may sleep.
356 */
357int intel_scu_ipc_iowrite32(u16 addr, u32 data)
358{
359 u16 x[4] = {addr, addr + 1, addr + 2, addr + 3};
360 return pwr_reg_rdwr(x, (u8 *)&data, 4, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
361}
362EXPORT_SYMBOL(intel_scu_ipc_iowrite32);
363
364/**
365 * intel_scu_ipc_readvv - read a set of registers
366 * @addr: register list
367 * @data: bytes to return
368 * @len: length of array
369 *
370 * Read registers. Returns 0 on success or an error code. All
371 * locking between SCU accesses is handled for the caller.
372 *
373 * The largest array length permitted by the hardware is 5 items.
374 *
375 * This function may sleep.
376 */
377int intel_scu_ipc_readv(u16 *addr, u8 *data, int len)
378{
379 return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);
380}
381EXPORT_SYMBOL(intel_scu_ipc_readv);
382
383/**
384 * intel_scu_ipc_writev - write a set of registers
385 * @addr: register list
386 * @data: bytes to write
387 * @len: length of array
388 *
389 * Write registers. Returns 0 on success or an error code. All
390 * locking between SCU accesses is handled for the caller.
391 *
392 * The largest array length permitted by the hardware is 5 items.
393 *
394 * This function may sleep.
395 *
396 */
397int intel_scu_ipc_writev(u16 *addr, u8 *data, int len)
398{
399 return pwr_reg_rdwr(addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);
400}
401EXPORT_SYMBOL(intel_scu_ipc_writev);
402
403/**
404 * intel_scu_ipc_update_register - r/m/w a register
405 * @addr: register address
406 * @bits: bits to update
407 * @mask: mask of bits to update
408 *
409 * Read-modify-write power control unit register. The first data argument
410 * must be register value and second is mask value
411 * mask is a bitmap that indicates which bits to update.
412 * 0 = masked. Don't modify this bit, 1 = modify this bit.
413 * returns 0 on success or an error code.
414 *
415 * This function may sleep. Locking between SCU accesses is handled
416 * for the caller.
417 */
418int intel_scu_ipc_update_register(u16 addr, u8 bits, u8 mask)
419{
420 u8 data[2] = { bits, mask };
421 return pwr_reg_rdwr(&addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_M);
422}
423EXPORT_SYMBOL(intel_scu_ipc_update_register);
424
425/**
426 * intel_scu_ipc_simple_command - send a simple command
427 * @cmd: command
428 * @sub: sub type
429 *
430 * Issue a simple command to the SCU. Do not use this interface if
431 * you must then access data as any data values may be overwritten
432 * by another SCU access by the time this function returns.
433 *
434 * This function may sleep. Locking for SCU accesses is handled for
435 * the caller.
436 */
437int intel_scu_ipc_simple_command(int cmd, int sub)
438{
439 struct intel_scu_ipc_dev *scu = &ipcdev;
440 int err;
441
442 mutex_lock(&ipclock);
443 if (scu->dev == NULL) {
444 mutex_unlock(&ipclock);
445 return -ENODEV;
446 }
447 ipc_command(scu, sub << 12 | cmd);
448 err = intel_scu_ipc_check_status(scu);
449 mutex_unlock(&ipclock);
450 return err;
451}
452EXPORT_SYMBOL(intel_scu_ipc_simple_command);
453
454/**
455 * intel_scu_ipc_command - command with data
456 * @cmd: command
457 * @sub: sub type
458 * @in: input data
459 * @inlen: input length in dwords
460 * @out: output data
461 * @outlein: output length in dwords
462 *
463 * Issue a command to the SCU which involves data transfers. Do the
464 * data copies under the lock but leave it for the caller to interpret
465 */
466int intel_scu_ipc_command(int cmd, int sub, u32 *in, int inlen,
467 u32 *out, int outlen)
468{
469 struct intel_scu_ipc_dev *scu = &ipcdev;
470 int i, err;
471
472 mutex_lock(&ipclock);
473 if (scu->dev == NULL) {
474 mutex_unlock(&ipclock);
475 return -ENODEV;
476 }
477
478 for (i = 0; i < inlen; i++)
479 ipc_data_writel(scu, *in++, 4 * i);
480
481 ipc_command(scu, (inlen << 16) | (sub << 12) | cmd);
482 err = intel_scu_ipc_check_status(scu);
483
484 if (!err) {
485 for (i = 0; i < outlen; i++)
486 *out++ = ipc_data_readl(scu, 4 * i);
487 }
488
489 mutex_unlock(&ipclock);
490 return err;
491}
492EXPORT_SYMBOL(intel_scu_ipc_command);
493
494/* I2C commands */
495#define IPC_I2C_WRITE 1 /* I2C Write command */
496#define IPC_I2C_READ 2 /* I2C Read command */
497
498/**
499 * intel_scu_ipc_i2c_cntrl - I2C read/write operations
500 * @addr: I2C address + command bits
501 * @data: data to read/write
502 *
503 * Perform an an I2C read/write operation via the SCU. All locking is
504 * handled for the caller. This function may sleep.
505 *
506 * Returns an error code or 0 on success.
507 *
508 * This has to be in the IPC driver for the locking.
509 */
510int intel_scu_ipc_i2c_cntrl(u32 addr, u32 *data)
511{
512 struct intel_scu_ipc_dev *scu = &ipcdev;
513 u32 cmd = 0;
514
515 mutex_lock(&ipclock);
516 if (scu->dev == NULL) {
517 mutex_unlock(&ipclock);
518 return -ENODEV;
519 }
520 cmd = (addr >> 24) & 0xFF;
521 if (cmd == IPC_I2C_READ) {
522 writel(addr, scu->i2c_base + IPC_I2C_CNTRL_ADDR);
523 /* Write not getting updated without delay */
524 mdelay(1);
525 *data = readl(scu->i2c_base + I2C_DATA_ADDR);
526 } else if (cmd == IPC_I2C_WRITE) {
527 writel(*data, scu->i2c_base + I2C_DATA_ADDR);
528 mdelay(1);
529 writel(addr, scu->i2c_base + IPC_I2C_CNTRL_ADDR);
530 } else {
531 dev_err(scu->dev,
532 "intel_scu_ipc: I2C INVALID_CMD = 0x%x\n", cmd);
533
534 mutex_unlock(&ipclock);
535 return -EIO;
536 }
537 mutex_unlock(&ipclock);
538 return 0;
539}
540EXPORT_SYMBOL(intel_scu_ipc_i2c_cntrl);
541
542/*
543 * Interrupt handler gets called when ioc bit of IPC_COMMAND_REG set to 1
544 * When ioc bit is set to 1, caller api must wait for interrupt handler called
545 * which in turn unlocks the caller api. Currently this is not used
546 *
547 * This is edge triggered so we need take no action to clear anything
548 */
549static irqreturn_t ioc(int irq, void *dev_id)
550{
551 struct intel_scu_ipc_dev *scu = dev_id;
552
553 if (scu->irq_mode)
554 complete(&scu->cmd_complete);
555
556 return IRQ_HANDLED;
557}
558
559/**
560 * ipc_probe - probe an Intel SCU IPC
561 * @pdev: the PCI device matching
562 * @id: entry in the match table
563 *
564 * Enable and install an intel SCU IPC. This appears in the PCI space
565 * but uses some hard coded addresses as well.
566 */
567static int ipc_probe(struct pci_dev *pdev, const struct pci_device_id *id)
568{
569 int platform; /* Platform type */
570 int err;
571 struct intel_scu_ipc_dev *scu = &ipcdev;
572 struct intel_scu_ipc_pdata_t *pdata;
573
574 platform = intel_mid_identify_cpu();
575 if (platform == 0)
576 return -ENODEV;
577
578 if (scu->dev) /* We support only one SCU */
579 return -EBUSY;
580
581 pdata = (struct intel_scu_ipc_pdata_t *)id->driver_data;
582
583 scu->dev = &pdev->dev;
584 scu->irq_mode = pdata->irq_mode;
585
586 err = pcim_enable_device(pdev);
587 if (err)
588 return err;
589
590 err = pcim_iomap_regions(pdev, 1 << 0, pci_name(pdev));
591 if (err)
592 return err;
593
594 init_completion(&scu->cmd_complete);
595
596 err = devm_request_irq(&pdev->dev, pdev->irq, ioc, 0, "intel_scu_ipc",
597 scu);
598 if (err)
599 return err;
600
601 scu->ipc_base = pcim_iomap_table(pdev)[0];
602
603 scu->i2c_base = ioremap_nocache(pdata->i2c_base, pdata->i2c_len);
604 if (!scu->i2c_base)
605 return -ENOMEM;
606
607 intel_scu_devices_create();
608
609 pci_set_drvdata(pdev, scu);
610 return 0;
611}
612
613static const struct pci_device_id pci_ids[] = {
614 {
615 PCI_VDEVICE(INTEL, PCI_DEVICE_ID_LINCROFT),
616 (kernel_ulong_t)&intel_scu_ipc_lincroft_pdata,
617 }, {
618 PCI_VDEVICE(INTEL, PCI_DEVICE_ID_PENWELL),
619 (kernel_ulong_t)&intel_scu_ipc_penwell_pdata,
620 }, {
621 PCI_VDEVICE(INTEL, PCI_DEVICE_ID_CLOVERVIEW),
622 (kernel_ulong_t)&intel_scu_ipc_penwell_pdata,
623 }, {
624 PCI_VDEVICE(INTEL, PCI_DEVICE_ID_TANGIER),
625 (kernel_ulong_t)&intel_scu_ipc_tangier_pdata,
626 }, {
627 0,
628 }
629};
630
631static struct pci_driver ipc_driver = {
632 .driver = {
633 .suppress_bind_attrs = true,
634 },
635 .name = "intel_scu_ipc",
636 .id_table = pci_ids,
637 .probe = ipc_probe,
638};
639builtin_pci_driver(ipc_driver);
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);