1 // SPDX-License-Identifier: GPL-2.0
3  * Driver for the Intel SCU IPC mechanism
5  * (C) Copyright 2008-2010,2015 Intel Corporation
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
12  * IPC-1 Driver provides an API for power control unit registers (e.g. MSIC)
27 /* IPC defines the following message types */
33 #define IPC_CMD_PCNTRL_M      2 /* Register read-modify-write */
36  * IPC register summary
38  * IPC register blocks are memory mapped at fixed address of PCI BAR 0.
39  * To read or write information to the SCU, driver writes to IPC-1 memory
40  * mapped registers. The following is the IPC mechanism
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
52 #define IPC_WWBUF_SIZE    20		/* IPC Write buffer Size */
53 #define IPC_RWBUF_SIZE    20		/* IPC Read buffer Size */
54 #define IPC_IOC	          0x100		/* IPC command register IOC bit */
71  * IPC Write/Read Buffers:
89  * intel_scu_ipc_dev_get() - Get SCU IPC instance
91  * The recommended new API takes SCU IPC instance as parameter and this
93  * sure the driver providing the IPC functionality cannot be unloaded
98  * Returns %NULL if SCU IPC is not currently available.
106 		get_device(&ipcdev->dev);  in intel_scu_ipc_dev_get()
108 		 * Prevent the IPC provider from being unloaded while it  in intel_scu_ipc_dev_get()
111 		if (!try_module_get(ipcdev->owner))  in intel_scu_ipc_dev_get()
112 			put_device(&ipcdev->dev);  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
127  * intel_scu_ipc_dev_get() and allows the driver providing IPC to be
133 		module_put(scu->owner);  in intel_scu_ipc_dev_put()
134 		put_device(&scu->dev);  in intel_scu_ipc_dev_put()
146 	struct intel_scu_ipc_dev *scu = dr->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
157  * sure the driver providing the IPC functionality cannot be unloaded
160  * Returns %NULL if SCU IPC is not currently available.
177 	dr->scu = scu;  in devm_intel_scu_ipc_dev_get()
185  * Send ipc command
189  * |rfu2(8) | size(8) | command id(4) | rfu1(3) | ioc(1) | command(8)|
193 	reinit_completion(&scu->cmd_complete);  in ipc_command()
194 	writel(cmd | IPC_IOC, scu->ipc_base);  in ipc_command()
198  * Write ipc data
199  * IPC Write Buffer (Write Only):
200  * 16-byte buffer for sending data associated with IPC command to
205 	writel(data, scu->ipc_base + IPC_WRITE_BUFFER + offset);  in ipc_data_writel()
210  * Driver will read this register to get the ready/busy status of the IPC
211  * block and error status of the IPC command that was just processed by SCU
217 	return __raw_readl(scu->ipc_base + IPC_STATUS);  in ipc_read_status()
220 /* Read ipc byte data */
223 	return readb(scu->ipc_base + IPC_READ_BUFFER + offset);  in ipc_data_readb()
226 /* Read ipc u32 data */
229 	return readl(scu->ipc_base + IPC_READ_BUFFER + offset);  in ipc_data_readl()
242 			return (status & IPC_STATUS_ERR) ? -EIO : 0;  in busy_loop()
247 	return -ETIMEDOUT;  in busy_loop()
250 /* Wait till ipc ioc interrupt is received or timeout in 10 HZ */
255 	if (!wait_for_completion_timeout(&scu->cmd_complete, IPC_TIMEOUT))  in ipc_wait_for_interrupt()
256 		return -ETIMEDOUT;  in ipc_wait_for_interrupt()
260 		return -EIO;  in ipc_wait_for_interrupt()
267 	return scu->irq > 0 ? ipc_wait_for_interrupt(scu) : busy_loop(scu);  in intel_scu_ipc_check_status()
287 		return -ENODEV;  in pwr_reg_rdwr()
304 		ipc_command(scu, (count * 3) << 16 | id << 12 | 0 << 8 | op);  in pwr_reg_rdwr()
315 		memcpy_fromio(cbuf, scu->ipc_base + 0x90, 16);  in pwr_reg_rdwr()
324  * intel_scu_ipc_dev_ioread8() - Read a byte via the SCU
325  * @scu: Optional SCU IPC instance
341  * intel_scu_ipc_dev_iowrite8() - Write a byte via the SCU
342  * @scu: Optional SCU IPC instance
358  * intel_scu_ipc_dev_readv() - Read a set of registers
359  * @scu: Optional SCU IPC instance
379  * intel_scu_ipc_dev_writev() - Write a set of registers
380  * @scu: Optional SCU IPC instance
400  * intel_scu_ipc_dev_update() - Update a register
401  * @scu: Optional SCU IPC instance
406  * Read-modify-write power control unit register. The first data argument
423  * intel_scu_ipc_dev_simple_command() - Send a simple command
424  * @scu: Optional SCU IPC instance
446 		return -ENODEV;  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()
460  * intel_scu_ipc_dev_command_with_size() - Command with data
461  * @scu: Optional SCU IPC instance
466  * @size: Input size written to the IPC command register in whatever
485 		return -EINVAL;  in intel_scu_ipc_dev_command_with_size()
492 		return -ENODEV;  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()
531 	writel(status | IPC_STATUS_IRQ, scu->ipc_base + IPC_STATUS);  in ioc()
532 	complete(&scu->cmd_complete);  in ioc()
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()
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.
570 	/* We support only one IPC */  in __intel_scu_ipc_register()
572 		err = -EBUSY;  in __intel_scu_ipc_register()
578 		err = -ENOMEM;  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()
588 	if (!request_mem_region(scu_data->mem.start, resource_size(&scu_data->mem),  in __intel_scu_ipc_register()
590 		err = -EBUSY;  in __intel_scu_ipc_register()
594 	ipc_base = ioremap(scu_data->mem.start, resource_size(&scu_data->mem));  in __intel_scu_ipc_register()
596 		err = -ENOMEM;  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()
630 	release_mem_region(scu_data->mem.start, resource_size(&scu_data->mem));  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
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()
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.
695 	dr->scu = scu;  in __devm_intel_scu_ipc_register()