3  * Driver for the Intel SCU IPC mechanism
8  * SCU running in ARC processor communicates with other entity running in IA
9  * core through IPC mechanism which in turn messaging between IA core ad SCU.
10  * SCU has two IPC mechanism IPC-1 and IPC-2. IPC-1 is used between IA32 and
11  * SCU where IPC-2 is used between P-Unit and SCU. This driver delas with
41  * To read or write information to the SCU, driver writes to IPC-1 memory
48  *    the IPC-1 register block, causing an interrupt to the SCU
50  * 3. SCU firmware decodes this interrupt and IPC message and the appropriate
74  * 16 byte buffer for sending and receiving data to and from SCU.
83 static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
90  * intel_scu_ipc_dev_get() - Get SCU IPC instance
92  * The recommended new API takes SCU IPC instance as parameter and this
99  * Returns %NULL if SCU IPC is not currently available.
122  * intel_scu_ipc_dev_put() - Put SCU IPC instance
123  * @scu: SCU IPC instance
125  * This function releases the SCU IPC instance retrieved from
129 void intel_scu_ipc_dev_put(struct intel_scu_ipc_dev *scu)  in intel_scu_ipc_dev_put()  argument
131 	if (scu) {  in intel_scu_ipc_dev_put()
132 		module_put(scu->owner);  in intel_scu_ipc_dev_put()
133 		put_device(&scu->dev);  in intel_scu_ipc_dev_put()
139 	struct intel_scu_ipc_dev *scu;  member
145 	struct intel_scu_ipc_dev *scu = dr->scu;  in devm_intel_scu_ipc_dev_release()  local
147 	intel_scu_ipc_dev_put(scu);  in devm_intel_scu_ipc_dev_release()
151  * devm_intel_scu_ipc_dev_get() - Allocate managed SCU IPC device
152  * @dev: Device requesting the SCU IPC device
154  * The recommended new API takes SCU IPC instance as parameter and this
159  * Returns %NULL if SCU IPC is not currently available.
164 	struct intel_scu_ipc_dev *scu;  in devm_intel_scu_ipc_dev_get()  local
170 	scu = intel_scu_ipc_dev_get();  in devm_intel_scu_ipc_dev_get()
171 	if (!scu) {  in devm_intel_scu_ipc_dev_get()
176 	dr->scu = scu;  in devm_intel_scu_ipc_dev_get()
179 	return scu;  in devm_intel_scu_ipc_dev_get()
186  * A write to this register results in an interrupt to the SCU core processor
190 static inline void ipc_command(struct intel_scu_ipc_dev *scu, u32 cmd)  in ipc_command()  argument
192 	reinit_completion(&scu->cmd_complete);  in ipc_command()
193 	writel(cmd | IPC_IOC, scu->ipc_base);  in ipc_command()
200  * SCU. Size of the data is specified in the IPC_COMMAND_REG register
202 static inline void ipc_data_writel(struct intel_scu_ipc_dev *scu, u32 data, u32 offset)  in ipc_data_writel()  argument
204 	writel(data, scu->ipc_base + IPC_WRITE_BUFFER + offset);  in ipc_data_writel()
210  * block and error status of the IPC command that was just processed by SCU
214 static inline u8 ipc_read_status(struct intel_scu_ipc_dev *scu)  in ipc_read_status()  argument
216 	return __raw_readl(scu->ipc_base + IPC_STATUS);  in ipc_read_status()
220 static inline u32 ipc_data_readl(struct intel_scu_ipc_dev *scu, u32 offset)  in ipc_data_readl()  argument
222 	return readl(scu->ipc_base + IPC_READ_BUFFER + offset);  in ipc_data_readl()
225 /* Wait till scu status is busy */
226 static inline int busy_loop(struct intel_scu_ipc_dev *scu)  in busy_loop()  argument
231 	err = readx_poll_timeout(ipc_read_status, scu, status, !(status & IPC_STATUS_BUSY),  in busy_loop()
240 static inline int ipc_wait_for_interrupt(struct intel_scu_ipc_dev *scu)  in ipc_wait_for_interrupt()  argument
244 	wait_for_completion_timeout(&scu->cmd_complete, IPC_TIMEOUT);  in ipc_wait_for_interrupt()
246 	status = ipc_read_status(scu);  in ipc_wait_for_interrupt()
256 static int intel_scu_ipc_check_status(struct intel_scu_ipc_dev *scu)  in intel_scu_ipc_check_status()  argument
258 	return scu->data.irq > 0 ? ipc_wait_for_interrupt(scu) : busy_loop(scu);  in intel_scu_ipc_check_status()
261 static struct intel_scu_ipc_dev *intel_scu_ipc_get(struct intel_scu_ipc_dev *scu)  in intel_scu_ipc_get()  argument
265 	if (!scu)  in intel_scu_ipc_get()
266 		scu = ipcdev;  in intel_scu_ipc_get()
267 	if (!scu)  in intel_scu_ipc_get()
270 	status = ipc_read_status(scu);  in intel_scu_ipc_get()
272 		dev_dbg(&scu->dev, "device is busy\n");  in intel_scu_ipc_get()
276 	return scu;  in intel_scu_ipc_get()
280 static int pwr_reg_rdwr(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,  in pwr_reg_rdwr()  argument
293 	scu = intel_scu_ipc_get(scu);  in pwr_reg_rdwr()
294 	if (IS_ERR(scu))  in pwr_reg_rdwr()
295 		return PTR_ERR(scu);  in pwr_reg_rdwr()
304 			ipc_data_writel(scu, wbuf[nc], offset);  in pwr_reg_rdwr()
305 		ipc_command(scu, (count * 2) << 16 | id << 12 | 0 << 8 | op);  in pwr_reg_rdwr()
310 			ipc_data_writel(scu, wbuf[nc], offset);  in pwr_reg_rdwr()
311 		ipc_command(scu, (count * 3) << 16 | id << 12 | 0 << 8 | op);  in pwr_reg_rdwr()
315 		ipc_data_writel(scu, wbuf[0], 0); /* Write wbuff */  in pwr_reg_rdwr()
316 		ipc_command(scu, 4 << 16 | id << 12 | 0 << 8 | op);  in pwr_reg_rdwr()
319 	err = intel_scu_ipc_check_status(scu);  in pwr_reg_rdwr()
325 		wbuf[nc] = ipc_data_readl(scu, offset);  in pwr_reg_rdwr()
332  * intel_scu_ipc_dev_ioread8() - Read a byte via the SCU
333  * @scu: Optional SCU IPC instance
334  * @addr: Register on SCU
338  * locking between SCU accesses is handled for the caller.
342 int intel_scu_ipc_dev_ioread8(struct intel_scu_ipc_dev *scu, u16 addr, u8 *data)  in intel_scu_ipc_dev_ioread8()  argument
344 	return pwr_reg_rdwr(scu, &addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);  in intel_scu_ipc_dev_ioread8()
349  * intel_scu_ipc_dev_iowrite8() - Write a byte via the SCU
350  * @scu: Optional SCU IPC instance
351  * @addr: Register on SCU
355  * locking between SCU accesses is handled for the caller.
359 int intel_scu_ipc_dev_iowrite8(struct intel_scu_ipc_dev *scu, u16 addr, u8 data)  in intel_scu_ipc_dev_iowrite8()  argument
361 	return pwr_reg_rdwr(scu, &addr, &data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);  in intel_scu_ipc_dev_iowrite8()
367  * @scu: Optional SCU IPC instance
373  * between SCU accesses is handled for the caller.
379 int intel_scu_ipc_dev_readv(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,  in intel_scu_ipc_dev_readv()  argument
382 	return pwr_reg_rdwr(scu, addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);  in intel_scu_ipc_dev_readv()
388  * @scu: Optional SCU IPC instance
394  * between SCU accesses is handled for the caller.
400 int intel_scu_ipc_dev_writev(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,  in intel_scu_ipc_dev_writev()  argument
403 	return pwr_reg_rdwr(scu, addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);  in intel_scu_ipc_dev_writev()
409  * @scu: Optional SCU IPC instance
419  * This function may sleep. Locking between SCU accesses is handled
422 int intel_scu_ipc_dev_update(struct intel_scu_ipc_dev *scu, u16 addr, u8 data,  in intel_scu_ipc_dev_update()  argument
426 	return pwr_reg_rdwr(scu, &addr, tmp, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_M);  in intel_scu_ipc_dev_update()
432  * @scu: Optional SCU IPC instance
436  * Issue a simple command to the SCU. Do not use this interface if you must
437  * then access data as any data values may be overwritten by another SCU
440  * This function may sleep. Locking for SCU accesses is handled for the
443 int intel_scu_ipc_dev_simple_command(struct intel_scu_ipc_dev *scu, int cmd,  in intel_scu_ipc_dev_simple_command()  argument
451 	scu = intel_scu_ipc_get(scu);  in intel_scu_ipc_dev_simple_command()
452 	if (IS_ERR(scu))  in intel_scu_ipc_dev_simple_command()
453 		return PTR_ERR(scu);  in intel_scu_ipc_dev_simple_command()
456 	ipc_command(scu, cmdval);  in intel_scu_ipc_dev_simple_command()
457 	err = intel_scu_ipc_check_status(scu);  in intel_scu_ipc_dev_simple_command()
459 		dev_err(&scu->dev, "IPC command %#x failed with %d\n", cmdval, err);  in intel_scu_ipc_dev_simple_command()
466  * @scu: Optional SCU IPC instance
477  * Issue a command to the SCU which involves data transfers. Do the
480 int intel_scu_ipc_dev_command_with_size(struct intel_scu_ipc_dev *scu, int cmd,  in intel_scu_ipc_dev_command_with_size()  argument
494 	scu = intel_scu_ipc_get(scu);  in intel_scu_ipc_dev_command_with_size()
495 	if (IS_ERR(scu))  in intel_scu_ipc_dev_command_with_size()
496 		return PTR_ERR(scu);  in intel_scu_ipc_dev_command_with_size()
500 		ipc_data_writel(scu, inbuf[i], 4 * i);  in intel_scu_ipc_dev_command_with_size()
503 	ipc_command(scu, cmdval);  in intel_scu_ipc_dev_command_with_size()
504 	err = intel_scu_ipc_check_status(scu);  in intel_scu_ipc_dev_command_with_size()
506 		dev_err(&scu->dev, "IPC command %#x failed with %d\n", cmdval, err);  in intel_scu_ipc_dev_command_with_size()
511 		outbuf[i] = ipc_data_readl(scu, 4 * i);  in intel_scu_ipc_dev_command_with_size()
528 	struct intel_scu_ipc_dev *scu = dev_id;  in ioc()  local
529 	int status = ipc_read_status(scu);  in ioc()
531 	writel(status | IPC_STATUS_IRQ, scu->ipc_base + IPC_STATUS);  in ioc()
532 	complete(&scu->cmd_complete);  in ioc()
539 	struct intel_scu_ipc_dev *scu = container_of(dev, struct intel_scu_ipc_dev, dev);  in intel_scu_ipc_release()  local
540 	struct intel_scu_ipc_data *data = &scu->data;  in intel_scu_ipc_release()
543 		free_irq(data->irq, scu);  in intel_scu_ipc_release()
544 	iounmap(scu->ipc_base);  in intel_scu_ipc_release()
546 	kfree(scu);  in intel_scu_ipc_release()
550  * __intel_scu_ipc_register() - Register SCU IPC device
552  * @scu_data: Data used to configure SCU IPC
553  * @owner: Module registering the SCU IPC device
555  * Call this function to register SCU IPC mechanism under @parent.
556  * Returns pointer to the new SCU IPC device or ERR_PTR() in case of
558  * SCU IPC calls itself.
567 	struct intel_scu_ipc_dev *scu;  in __intel_scu_ipc_register()  local
576 	scu = kzalloc(sizeof(*scu), GFP_KERNEL);  in __intel_scu_ipc_register()
577 	if (!scu)  in __intel_scu_ipc_register()
580 	scu->owner = owner;  in __intel_scu_ipc_register()
581 	scu->dev.parent = parent;  in __intel_scu_ipc_register()
582 	scu->dev.class = &intel_scu_ipc_class;  in __intel_scu_ipc_register()
583 	scu->dev.release = intel_scu_ipc_release;  in __intel_scu_ipc_register()
585 	memcpy(&scu->data, scu_data, sizeof(scu->data));  in __intel_scu_ipc_register()
586 	data = &scu->data;  in __intel_scu_ipc_register()
599 	scu->ipc_base = ipc_base;  in __intel_scu_ipc_register()
600 	init_completion(&scu->cmd_complete);  in __intel_scu_ipc_register()
603 		err = request_irq(data->irq, ioc, 0, "intel_scu_ipc", scu);  in __intel_scu_ipc_register()
610 	 * releasing the SCU IPC resources once refcount drops to zero.  in __intel_scu_ipc_register()
612 	dev_set_name(&scu->dev, "intel_scu_ipc");  in __intel_scu_ipc_register()
613 	err = device_register(&scu->dev);  in __intel_scu_ipc_register()
615 		put_device(&scu->dev);  in __intel_scu_ipc_register()
620 	ipcdev = scu;  in __intel_scu_ipc_register()
621 	return scu;  in __intel_scu_ipc_register()
628 	kfree(scu);  in __intel_scu_ipc_register()
634  * intel_scu_ipc_unregister() - Unregister SCU IPC
635  * @scu: SCU IPC handle
637  * This unregisters the SCU IPC device and releases the acquired
640 void intel_scu_ipc_unregister(struct intel_scu_ipc_dev *scu)  in intel_scu_ipc_unregister()  argument
646 		device_unregister(&scu->dev);  in intel_scu_ipc_unregister()
654 	struct intel_scu_ipc_dev *scu = dr->scu;  in devm_intel_scu_ipc_unregister()  local
656 	intel_scu_ipc_unregister(scu);  in devm_intel_scu_ipc_unregister()
660  * __devm_intel_scu_ipc_register() - Register managed SCU IPC device
662  * @scu_data: Data used to configure SCU IPC
663  * @owner: Module registering the SCU IPC device
665  * Call this function to register managed SCU IPC mechanism under
666  * @parent. Returns pointer to the new SCU IPC device or ERR_PTR() in
668  * to do SCU IPC calls itself.
676 	struct intel_scu_ipc_dev *scu;  in __devm_intel_scu_ipc_register()  local
682 	scu = __intel_scu_ipc_register(parent, scu_data, owner);  in __devm_intel_scu_ipc_register()
683 	if (IS_ERR(scu)) {  in __devm_intel_scu_ipc_register()
685 		return scu;  in __devm_intel_scu_ipc_register()
688 	dr->scu = scu;  in __devm_intel_scu_ipc_register()
691 	return scu;  in __devm_intel_scu_ipc_register()