2 * intel_scu_ipc.c: Driver for the Intel SCU IPC mechanism
4 * (C) Copyright 2008-2010,2015 Intel Corporation
5 * Author: Sreedhara DS (sreedhara.ds@intel.com)
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
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.
19 #include <linux/delay.h>
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/device.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>
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 */
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 */
43 * IPC register summary
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
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.
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
55 * 3. SCU firmware decodes this interrupt and IPC message and the appropriate
56 * message handler is called within firmware.
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 */
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
68 /* intel scu ipc driver data */
69 struct intel_scu_ipc_pdata_t
{
75 static struct intel_scu_ipc_pdata_t intel_scu_ipc_lincroft_pdata
= {
76 .i2c_base
= 0xff12b000,
81 /* Penwell and Cloverview */
82 static struct intel_scu_ipc_pdata_t intel_scu_ipc_penwell_pdata
= {
83 .i2c_base
= 0xff12b000,
88 static struct intel_scu_ipc_pdata_t intel_scu_ipc_tangier_pdata
= {
89 .i2c_base
= 0xff00d000,
94 struct intel_scu_ipc_dev
{
96 void __iomem
*ipc_base
;
97 void __iomem
*i2c_base
;
98 struct completion cmd_complete
;
102 static struct intel_scu_ipc_dev ipcdev
; /* Only one for now */
105 * IPC Read Buffer (Read Only):
106 * 16 byte buffer for receiving data from SCU, if IPC command
107 * processing results in response data
109 #define IPC_READ_BUFFER 0x90
111 #define IPC_I2C_CNTRL_ADDR 0
112 #define I2C_DATA_ADDR 0x04
114 static DEFINE_MUTEX(ipclock
); /* lock used to prevent multiple call to SCU */
118 * Command Register (Write Only):
119 * A write to this register results in an interrupt to the SCU core processor
121 * |rfu2(8) | size(8) | command id(4) | rfu1(3) | ioc(1) | command(8)|
123 static inline void ipc_command(struct intel_scu_ipc_dev
*scu
, u32 cmd
)
126 reinit_completion(&scu
->cmd_complete
);
127 writel(cmd
| IPC_IOC
, scu
->ipc_base
);
129 writel(cmd
, scu
->ipc_base
);
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
138 static inline void ipc_data_writel(struct intel_scu_ipc_dev
*scu
, u32 data
, u32 offset
)
140 writel(data
, scu
->ipc_base
+ 0x80 + offset
);
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
148 * |rfu3(8)|error code(8)|initiator id(8)|cmd id(4)|rfu1(2)|error(1)|busy(1)|
150 static inline u8
ipc_read_status(struct intel_scu_ipc_dev
*scu
)
152 return __raw_readl(scu
->ipc_base
+ 0x04);
155 /* Read ipc byte data */
156 static inline u8
ipc_data_readb(struct intel_scu_ipc_dev
*scu
, u32 offset
)
158 return readb(scu
->ipc_base
+ IPC_READ_BUFFER
+ offset
);
161 /* Read ipc u32 data */
162 static inline u32
ipc_data_readl(struct intel_scu_ipc_dev
*scu
, u32 offset
)
164 return readl(scu
->ipc_base
+ IPC_READ_BUFFER
+ offset
);
167 /* Wait till scu status is busy */
168 static inline int busy_loop(struct intel_scu_ipc_dev
*scu
)
170 u32 status
= ipc_read_status(scu
);
171 u32 loop_count
= 100000;
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
);
179 if (status
& BIT(0)) {
180 dev_err(scu
->dev
, "IPC timed out");
190 /* Wait till ipc ioc interrupt is received or timeout in 3 HZ */
191 static inline int ipc_wait_for_interrupt(struct intel_scu_ipc_dev
*scu
)
195 if (!wait_for_completion_timeout(&scu
->cmd_complete
, 3 * HZ
)) {
196 dev_err(scu
->dev
, "IPC timed out\n");
200 status
= ipc_read_status(scu
);
207 static int intel_scu_ipc_check_status(struct intel_scu_ipc_dev
*scu
)
209 return scu
->irq_mode
? ipc_wait_for_interrupt(scu
) : busy_loop(scu
);
212 /* Read/Write power control(PMIC in Langwell, MSIC in PenWell) registers */
213 static int pwr_reg_rdwr(u16
*addr
, u8
*data
, u32 count
, u32 op
, u32 id
)
215 struct intel_scu_ipc_dev
*scu
= &ipcdev
;
219 u8 cbuf
[IPC_WWBUF_SIZE
];
220 u32
*wbuf
= (u32
*)&cbuf
;
222 memset(cbuf
, 0, sizeof(cbuf
));
224 mutex_lock(&ipclock
);
226 if (scu
->dev
== NULL
) {
227 mutex_unlock(&ipclock
);
231 for (nc
= 0; nc
< count
; nc
++, offset
+= 2) {
232 cbuf
[offset
] = addr
[nc
];
233 cbuf
[offset
+ 1] = addr
[nc
] >> 8;
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
);
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
);
260 mutex_unlock(&ipclock
);
265 * intel_scu_ipc_ioread8 - read a word via the SCU
266 * @addr: register on SCU
267 * @data: return pointer for read byte
269 * Read a single register. Returns 0 on success or an error code. All
270 * locking between SCU accesses is handled for the caller.
272 * This function may sleep.
274 int intel_scu_ipc_ioread8(u16 addr
, u8
*data
)
276 return pwr_reg_rdwr(&addr
, data
, 1, IPCMSG_PCNTRL
, IPC_CMD_PCNTRL_R
);
278 EXPORT_SYMBOL(intel_scu_ipc_ioread8
);
281 * intel_scu_ipc_ioread16 - read a word via the SCU
282 * @addr: register on SCU
283 * @data: return pointer for read word
285 * Read a register pair. Returns 0 on success or an error code. All
286 * locking between SCU accesses is handled for the caller.
288 * This function may sleep.
290 int intel_scu_ipc_ioread16(u16 addr
, u16
*data
)
292 u16 x
[2] = {addr
, addr
+ 1};
293 return pwr_reg_rdwr(x
, (u8
*)data
, 2, IPCMSG_PCNTRL
, IPC_CMD_PCNTRL_R
);
295 EXPORT_SYMBOL(intel_scu_ipc_ioread16
);
298 * intel_scu_ipc_ioread32 - read a dword via the SCU
299 * @addr: register on SCU
300 * @data: return pointer for read dword
302 * Read four registers. Returns 0 on success or an error code. All
303 * locking between SCU accesses is handled for the caller.
305 * This function may sleep.
307 int intel_scu_ipc_ioread32(u16 addr
, u32
*data
)
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
);
312 EXPORT_SYMBOL(intel_scu_ipc_ioread32
);
315 * intel_scu_ipc_iowrite8 - write a byte via the SCU
316 * @addr: register on SCU
317 * @data: byte to write
319 * Write a single register. Returns 0 on success or an error code. All
320 * locking between SCU accesses is handled for the caller.
322 * This function may sleep.
324 int intel_scu_ipc_iowrite8(u16 addr
, u8 data
)
326 return pwr_reg_rdwr(&addr
, &data
, 1, IPCMSG_PCNTRL
, IPC_CMD_PCNTRL_W
);
328 EXPORT_SYMBOL(intel_scu_ipc_iowrite8
);
331 * intel_scu_ipc_iowrite16 - write a word via the SCU
332 * @addr: register on SCU
333 * @data: word to write
335 * Write two registers. Returns 0 on success or an error code. All
336 * locking between SCU accesses is handled for the caller.
338 * This function may sleep.
340 int intel_scu_ipc_iowrite16(u16 addr
, u16 data
)
342 u16 x
[2] = {addr
, addr
+ 1};
343 return pwr_reg_rdwr(x
, (u8
*)&data
, 2, IPCMSG_PCNTRL
, IPC_CMD_PCNTRL_W
);
345 EXPORT_SYMBOL(intel_scu_ipc_iowrite16
);
348 * intel_scu_ipc_iowrite32 - write a dword via the SCU
349 * @addr: register on SCU
350 * @data: dword to write
352 * Write four registers. Returns 0 on success or an error code. All
353 * locking between SCU accesses is handled for the caller.
355 * This function may sleep.
357 int intel_scu_ipc_iowrite32(u16 addr
, u32 data
)
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
);
362 EXPORT_SYMBOL(intel_scu_ipc_iowrite32
);
365 * intel_scu_ipc_readvv - read a set of registers
366 * @addr: register list
367 * @data: bytes to return
368 * @len: length of array
370 * Read registers. Returns 0 on success or an error code. All
371 * locking between SCU accesses is handled for the caller.
373 * The largest array length permitted by the hardware is 5 items.
375 * This function may sleep.
377 int intel_scu_ipc_readv(u16
*addr
, u8
*data
, int len
)
379 return pwr_reg_rdwr(addr
, data
, len
, IPCMSG_PCNTRL
, IPC_CMD_PCNTRL_R
);
381 EXPORT_SYMBOL(intel_scu_ipc_readv
);
384 * intel_scu_ipc_writev - write a set of registers
385 * @addr: register list
386 * @data: bytes to write
387 * @len: length of array
389 * Write registers. Returns 0 on success or an error code. All
390 * locking between SCU accesses is handled for the caller.
392 * The largest array length permitted by the hardware is 5 items.
394 * This function may sleep.
397 int intel_scu_ipc_writev(u16
*addr
, u8
*data
, int len
)
399 return pwr_reg_rdwr(addr
, data
, len
, IPCMSG_PCNTRL
, IPC_CMD_PCNTRL_W
);
401 EXPORT_SYMBOL(intel_scu_ipc_writev
);
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
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.
415 * This function may sleep. Locking between SCU accesses is handled
418 int intel_scu_ipc_update_register(u16 addr
, u8 bits
, u8 mask
)
420 u8 data
[2] = { bits
, mask
};
421 return pwr_reg_rdwr(&addr
, data
, 1, IPCMSG_PCNTRL
, IPC_CMD_PCNTRL_M
);
423 EXPORT_SYMBOL(intel_scu_ipc_update_register
);
426 * intel_scu_ipc_simple_command - send a simple command
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.
434 * This function may sleep. Locking for SCU accesses is handled for
437 int intel_scu_ipc_simple_command(int cmd
, int sub
)
439 struct intel_scu_ipc_dev
*scu
= &ipcdev
;
442 mutex_lock(&ipclock
);
443 if (scu
->dev
== NULL
) {
444 mutex_unlock(&ipclock
);
447 ipc_command(scu
, sub
<< 12 | cmd
);
448 err
= intel_scu_ipc_check_status(scu
);
449 mutex_unlock(&ipclock
);
452 EXPORT_SYMBOL(intel_scu_ipc_simple_command
);
455 * intel_scu_ipc_command - command with data
459 * @inlen: input length in dwords
461 * @outlein: output length in dwords
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
466 int intel_scu_ipc_command(int cmd
, int sub
, u32
*in
, int inlen
,
467 u32
*out
, int outlen
)
469 struct intel_scu_ipc_dev
*scu
= &ipcdev
;
472 mutex_lock(&ipclock
);
473 if (scu
->dev
== NULL
) {
474 mutex_unlock(&ipclock
);
478 for (i
= 0; i
< inlen
; i
++)
479 ipc_data_writel(scu
, *in
++, 4 * i
);
481 ipc_command(scu
, (inlen
<< 16) | (sub
<< 12) | cmd
);
482 err
= intel_scu_ipc_check_status(scu
);
485 for (i
= 0; i
< outlen
; i
++)
486 *out
++ = ipc_data_readl(scu
, 4 * i
);
489 mutex_unlock(&ipclock
);
492 EXPORT_SYMBOL(intel_scu_ipc_command
);
495 #define IPC_I2C_WRITE 1 /* I2C Write command */
496 #define IPC_I2C_READ 2 /* I2C Read command */
499 * intel_scu_ipc_i2c_cntrl - I2C read/write operations
500 * @addr: I2C address + command bits
501 * @data: data to read/write
503 * Perform an an I2C read/write operation via the SCU. All locking is
504 * handled for the caller. This function may sleep.
506 * Returns an error code or 0 on success.
508 * This has to be in the IPC driver for the locking.
510 int intel_scu_ipc_i2c_cntrl(u32 addr
, u32
*data
)
512 struct intel_scu_ipc_dev
*scu
= &ipcdev
;
515 mutex_lock(&ipclock
);
516 if (scu
->dev
== NULL
) {
517 mutex_unlock(&ipclock
);
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 */
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
);
529 writel(addr
, scu
->i2c_base
+ IPC_I2C_CNTRL_ADDR
);
532 "intel_scu_ipc: I2C INVALID_CMD = 0x%x\n", cmd
);
534 mutex_unlock(&ipclock
);
537 mutex_unlock(&ipclock
);
540 EXPORT_SYMBOL(intel_scu_ipc_i2c_cntrl
);
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
547 * This is edge triggered so we need take no action to clear anything
549 static irqreturn_t
ioc(int irq
, void *dev_id
)
551 struct intel_scu_ipc_dev
*scu
= dev_id
;
554 complete(&scu
->cmd_complete
);
560 * ipc_probe - probe an Intel SCU IPC
561 * @pdev: the PCI device matching
562 * @id: entry in the match table
564 * Enable and install an intel SCU IPC. This appears in the PCI space
565 * but uses some hard coded addresses as well.
567 static int ipc_probe(struct pci_dev
*pdev
, const struct pci_device_id
*id
)
569 int platform
; /* Platform type */
571 struct intel_scu_ipc_dev
*scu
= &ipcdev
;
572 struct intel_scu_ipc_pdata_t
*pdata
;
574 platform
= intel_mid_identify_cpu();
578 if (scu
->dev
) /* We support only one SCU */
581 pdata
= (struct intel_scu_ipc_pdata_t
*)id
->driver_data
;
583 scu
->dev
= &pdev
->dev
;
584 scu
->irq_mode
= pdata
->irq_mode
;
586 err
= pcim_enable_device(pdev
);
590 err
= pcim_iomap_regions(pdev
, 1 << 0, pci_name(pdev
));
594 init_completion(&scu
->cmd_complete
);
596 err
= devm_request_irq(&pdev
->dev
, pdev
->irq
, ioc
, 0, "intel_scu_ipc",
601 scu
->ipc_base
= pcim_iomap_table(pdev
)[0];
603 scu
->i2c_base
= ioremap_nocache(pdata
->i2c_base
, pdata
->i2c_len
);
607 intel_scu_devices_create();
609 pci_set_drvdata(pdev
, scu
);
613 static const struct pci_device_id pci_ids
[] = {
615 PCI_VDEVICE(INTEL
, PCI_DEVICE_ID_LINCROFT
),
616 (kernel_ulong_t
)&intel_scu_ipc_lincroft_pdata
,
618 PCI_VDEVICE(INTEL
, PCI_DEVICE_ID_PENWELL
),
619 (kernel_ulong_t
)&intel_scu_ipc_penwell_pdata
,
621 PCI_VDEVICE(INTEL
, PCI_DEVICE_ID_CLOVERVIEW
),
622 (kernel_ulong_t
)&intel_scu_ipc_penwell_pdata
,
624 PCI_VDEVICE(INTEL
, PCI_DEVICE_ID_TANGIER
),
625 (kernel_ulong_t
)&intel_scu_ipc_tangier_pdata
,
631 static struct pci_driver ipc_driver
= {
633 .suppress_bind_attrs
= true,
635 .name
= "intel_scu_ipc",
639 builtin_pci_driver(ipc_driver
);