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
39  * To read or write information to the SCU, driver writes to IPC-1 memory
46  *    the IPC-1 register block, causing an interrupt to the SCU
48  * 3. SCU firmware decodes this interrupt and IPC message and the appropriate
72  * 16 byte buffer for sending and receiving data to and from SCU.
81 static DEFINE_MUTEX(ipclock); /* lock used to prevent multiple call to SCU */
89  * intel_scu_ipc_dev_get() - Get SCU IPC instance
91  * The recommended new API takes SCU IPC instance as parameter and this
98  * Returns %NULL if SCU IPC is not currently available.
102 	struct intel_scu_ipc_dev *scu = NULL;  in intel_scu_ipc_dev_get()  local
114 			scu = ipcdev;  in intel_scu_ipc_dev_get()
118 	return scu;  in intel_scu_ipc_dev_get()
123  * intel_scu_ipc_dev_put() - Put SCU IPC instance
124  * @scu: SCU IPC instance
126  * This function releases the SCU IPC instance retrieved from
130 void intel_scu_ipc_dev_put(struct intel_scu_ipc_dev *scu)  in intel_scu_ipc_dev_put()  argument
132 	if (scu) {  in intel_scu_ipc_dev_put()
133 		module_put(scu->owner);  in intel_scu_ipc_dev_put()
134 		put_device(&scu->dev);  in intel_scu_ipc_dev_put()
140 	struct intel_scu_ipc_dev *scu;  member
146 	struct intel_scu_ipc_dev *scu = dr->scu;  in devm_intel_scu_ipc_dev_release()  local
148 	intel_scu_ipc_dev_put(scu);  in devm_intel_scu_ipc_dev_release()
152  * devm_intel_scu_ipc_dev_get() - Allocate managed SCU IPC device
153  * @dev: Device requesting the SCU IPC device
155  * The recommended new API takes SCU IPC instance as parameter and this
160  * Returns %NULL if SCU IPC is not currently available.
165 	struct intel_scu_ipc_dev *scu;  in devm_intel_scu_ipc_dev_get()  local
171 	scu = intel_scu_ipc_dev_get();  in devm_intel_scu_ipc_dev_get()
172 	if (!scu) {  in devm_intel_scu_ipc_dev_get()
177 	dr->scu = scu;  in devm_intel_scu_ipc_dev_get()
180 	return scu;  in devm_intel_scu_ipc_dev_get()
187  * A write to this register results in an interrupt to the SCU core processor
191 static inline void ipc_command(struct intel_scu_ipc_dev *scu, u32 cmd)  in ipc_command()  argument
193 	reinit_completion(&scu->cmd_complete);  in ipc_command()
194 	writel(cmd | IPC_IOC, scu->ipc_base);  in ipc_command()
201  * SCU. Size of the data is specified in the IPC_COMMAND_REG register
203 static inline void ipc_data_writel(struct intel_scu_ipc_dev *scu, u32 data, u32 offset)  in ipc_data_writel()  argument
205 	writel(data, scu->ipc_base + IPC_WRITE_BUFFER + offset);  in ipc_data_writel()
211  * block and error status of the IPC command that was just processed by SCU
215 static inline u8 ipc_read_status(struct intel_scu_ipc_dev *scu)  in ipc_read_status()  argument
217 	return __raw_readl(scu->ipc_base + IPC_STATUS);  in ipc_read_status()
221 static inline u8 ipc_data_readb(struct intel_scu_ipc_dev *scu, u32 offset)  in ipc_data_readb()  argument
223 	return readb(scu->ipc_base + IPC_READ_BUFFER + offset);  in ipc_data_readb()
227 static inline u32 ipc_data_readl(struct intel_scu_ipc_dev *scu, u32 offset)  in ipc_data_readl()  argument
229 	return readl(scu->ipc_base + IPC_READ_BUFFER + offset);  in ipc_data_readl()
232 /* Wait till scu status is busy */
233 static inline int busy_loop(struct intel_scu_ipc_dev *scu)  in busy_loop()  argument
240 		status = ipc_read_status(scu);  in busy_loop()
251 static inline int ipc_wait_for_interrupt(struct intel_scu_ipc_dev *scu)  in ipc_wait_for_interrupt()  argument
255 	if (!wait_for_completion_timeout(&scu->cmd_complete, IPC_TIMEOUT))  in ipc_wait_for_interrupt()
258 	status = ipc_read_status(scu);  in ipc_wait_for_interrupt()
265 static int intel_scu_ipc_check_status(struct intel_scu_ipc_dev *scu)  in intel_scu_ipc_check_status()  argument
267 	return scu->irq > 0 ? ipc_wait_for_interrupt(scu) : busy_loop(scu);  in intel_scu_ipc_check_status()
271 static int pwr_reg_rdwr(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,  in pwr_reg_rdwr()  argument
283 	if (!scu)  in pwr_reg_rdwr()
284 		scu = ipcdev;  in pwr_reg_rdwr()
285 	if (!scu) {  in pwr_reg_rdwr()
297 			ipc_data_writel(scu, wbuf[nc], offset);  in pwr_reg_rdwr()
298 		ipc_command(scu, (count * 2) << 16 | id << 12 | 0 << 8 | op);  in pwr_reg_rdwr()
303 			ipc_data_writel(scu, wbuf[nc], offset);  in pwr_reg_rdwr()
304 		ipc_command(scu, (count * 3) << 16 | id << 12 | 0 << 8 | op);  in pwr_reg_rdwr()
308 		ipc_data_writel(scu, wbuf[0], 0); /* Write wbuff */  in pwr_reg_rdwr()
309 		ipc_command(scu, 4 << 16 | id << 12 | 0 << 8 | op);  in pwr_reg_rdwr()
312 	err = intel_scu_ipc_check_status(scu);  in pwr_reg_rdwr()
315 		memcpy_fromio(cbuf, scu->ipc_base + 0x90, 16);  in pwr_reg_rdwr()
317 			data[nc] = ipc_data_readb(scu, nc);  in pwr_reg_rdwr()
324  * intel_scu_ipc_dev_ioread8() - Read a byte via the SCU
325  * @scu: Optional SCU IPC instance
326  * @addr: Register on SCU
330  * locking between SCU accesses is handled for the caller.
334 int intel_scu_ipc_dev_ioread8(struct intel_scu_ipc_dev *scu, u16 addr, u8 *data)  in intel_scu_ipc_dev_ioread8()  argument
336 	return pwr_reg_rdwr(scu, &addr, data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);  in intel_scu_ipc_dev_ioread8()
341  * intel_scu_ipc_dev_iowrite8() - Write a byte via the SCU
342  * @scu: Optional SCU IPC instance
343  * @addr: Register on SCU
347  * locking between SCU accesses is handled for the caller.
351 int intel_scu_ipc_dev_iowrite8(struct intel_scu_ipc_dev *scu, u16 addr, u8 data)  in intel_scu_ipc_dev_iowrite8()  argument
353 	return pwr_reg_rdwr(scu, &addr, &data, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);  in intel_scu_ipc_dev_iowrite8()
359  * @scu: Optional SCU IPC instance
365  * between SCU accesses is handled for the caller.
371 int intel_scu_ipc_dev_readv(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,  in intel_scu_ipc_dev_readv()  argument
374 	return pwr_reg_rdwr(scu, addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_R);  in intel_scu_ipc_dev_readv()
380  * @scu: Optional SCU IPC instance
386  * between SCU accesses is handled for the caller.
392 int intel_scu_ipc_dev_writev(struct intel_scu_ipc_dev *scu, u16 *addr, u8 *data,  in intel_scu_ipc_dev_writev()  argument
395 	return pwr_reg_rdwr(scu, addr, data, len, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_W);  in intel_scu_ipc_dev_writev()
401  * @scu: Optional SCU IPC instance
411  * This function may sleep. Locking between SCU accesses is handled
414 int intel_scu_ipc_dev_update(struct intel_scu_ipc_dev *scu, u16 addr, u8 data,  in intel_scu_ipc_dev_update()  argument
418 	return pwr_reg_rdwr(scu, &addr, tmp, 1, IPCMSG_PCNTRL, IPC_CMD_PCNTRL_M);  in intel_scu_ipc_dev_update()
424  * @scu: Optional SCU IPC instance
428  * Issue a simple command to the SCU. Do not use this interface if you must
429  * then access data as any data values may be overwritten by another SCU
432  * This function may sleep. Locking for SCU accesses is handled for the
435 int intel_scu_ipc_dev_simple_command(struct intel_scu_ipc_dev *scu, int cmd,  in intel_scu_ipc_dev_simple_command()  argument
442 	if (!scu)  in intel_scu_ipc_dev_simple_command()
443 		scu = ipcdev;  in intel_scu_ipc_dev_simple_command()
444 	if (!scu) {  in intel_scu_ipc_dev_simple_command()
448 	scu = ipcdev;  in intel_scu_ipc_dev_simple_command()
450 	ipc_command(scu, cmdval);  in intel_scu_ipc_dev_simple_command()
451 	err = intel_scu_ipc_check_status(scu);  in intel_scu_ipc_dev_simple_command()
454 		dev_err(&scu->dev, "IPC command %#x failed with %d\n", cmdval, err);  in intel_scu_ipc_dev_simple_command()
461  * @scu: Optional SCU IPC instance
472  * Issue a command to the SCU which involves data transfers. Do the
475 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
488 	if (!scu)  in intel_scu_ipc_dev_command_with_size()
489 		scu = ipcdev;  in intel_scu_ipc_dev_command_with_size()
490 	if (!scu) {  in intel_scu_ipc_dev_command_with_size()
497 		ipc_data_writel(scu, inbuf[i], 4 * i);  in intel_scu_ipc_dev_command_with_size()
500 	ipc_command(scu, cmdval);  in intel_scu_ipc_dev_command_with_size()
501 	err = intel_scu_ipc_check_status(scu);  in intel_scu_ipc_dev_command_with_size()
507 			outbuf[i] = ipc_data_readl(scu, 4 * i);  in intel_scu_ipc_dev_command_with_size()
514 		dev_err(&scu->dev, "IPC command %#x failed with %d\n", cmdval, err);  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;  in intel_scu_ipc_release()  local
541 	scu = container_of(dev, struct intel_scu_ipc_dev, dev);  in intel_scu_ipc_release()
542 	if (scu->irq > 0)  in intel_scu_ipc_release()
543 		free_irq(scu->irq, scu);  in intel_scu_ipc_release()
544 	iounmap(scu->ipc_base);  in intel_scu_ipc_release()
545 	release_mem_region(scu->mem.start, resource_size(&scu->mem));  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.
566 	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()
582 	scu->owner = owner;  in __intel_scu_ipc_register()
583 	scu->dev.parent = parent;  in __intel_scu_ipc_register()
584 	scu->dev.class = &intel_scu_ipc_class;  in __intel_scu_ipc_register()
585 	scu->dev.release = intel_scu_ipc_release;  in __intel_scu_ipc_register()
586 	dev_set_name(&scu->dev, "intel_scu_ipc");  in __intel_scu_ipc_register()
600 	scu->ipc_base = ipc_base;  in __intel_scu_ipc_register()
601 	scu->mem = scu_data->mem;  in __intel_scu_ipc_register()
602 	scu->irq = scu_data->irq;  in __intel_scu_ipc_register()
603 	init_completion(&scu->cmd_complete);  in __intel_scu_ipc_register()
605 	if (scu->irq > 0) {  in __intel_scu_ipc_register()
606 		err = request_irq(scu->irq, ioc, 0, "intel_scu_ipc", scu);  in __intel_scu_ipc_register()
613 	 * releasing the SCU IPC resources once refcount drops to zero.  in __intel_scu_ipc_register()
615 	err = device_register(&scu->dev);  in __intel_scu_ipc_register()
617 		put_device(&scu->dev);  in __intel_scu_ipc_register()
622 	ipcdev = scu;  in __intel_scu_ipc_register()
625 	return scu;  in __intel_scu_ipc_register()
632 	kfree(scu);  in __intel_scu_ipc_register()
641  * intel_scu_ipc_unregister() - Unregister SCU IPC
642  * @scu: SCU IPC handle
644  * This unregisters the SCU IPC device and releases the acquired
647 void intel_scu_ipc_unregister(struct intel_scu_ipc_dev *scu)  in intel_scu_ipc_unregister()  argument
652 		device_unregister(&scu->dev);  in intel_scu_ipc_unregister()
661 	struct intel_scu_ipc_dev *scu = dr->scu;  in devm_intel_scu_ipc_unregister()  local
663 	intel_scu_ipc_unregister(scu);  in devm_intel_scu_ipc_unregister()
667  * __devm_intel_scu_ipc_register() - Register managed SCU IPC device
669  * @scu_data: Data used to configure SCU IPC
670  * @owner: Module registering the SCU IPC device
672  * Call this function to register managed SCU IPC mechanism under
673  * @parent. Returns pointer to the new SCU IPC device or ERR_PTR() in
675  * to do SCU IPC calls itself.
683 	struct intel_scu_ipc_dev *scu;  in __devm_intel_scu_ipc_register()  local
689 	scu = __intel_scu_ipc_register(parent, scu_data, owner);  in __devm_intel_scu_ipc_register()
690 	if (IS_ERR(scu)) {  in __devm_intel_scu_ipc_register()
692 		return scu;  in __devm_intel_scu_ipc_register()
695 	dr->scu = scu;  in __devm_intel_scu_ipc_register()
698 	return scu;  in __devm_intel_scu_ipc_register()