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)
29 /* IPC defines the following message types */
35 #define IPC_CMD_PCNTRL_M      2 /* Register read-modify-write */
38  * IPC register summary
40  * IPC register blocks are memory mapped at fixed address of PCI BAR 0.
41  * To read or write information to the SCU, driver writes to IPC-1 memory
42  * mapped registers. The following is the IPC mechanism
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
54 #define IPC_WWBUF_SIZE    20		/* IPC Write buffer Size */
55 #define IPC_RWBUF_SIZE    20		/* IPC Read buffer Size */
56 #define IPC_IOC	          0x100		/* IPC command register IOC bit */
73  * IPC Write/Read Buffers:
90  * intel_scu_ipc_dev_get() - Get SCU IPC instance
92  * The recommended new API takes SCU IPC instance as parameter and this
94  * sure the driver providing the IPC functionality cannot be unloaded
99  * 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()
114 		put_device(&ipcdev->dev);  in intel_scu_ipc_dev_get()
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
126  * intel_scu_ipc_dev_get() and allows the driver providing IPC to be
132 		module_put(scu->owner);  in intel_scu_ipc_dev_put()
133 		put_device(&scu->dev);  in intel_scu_ipc_dev_put()
145 	struct intel_scu_ipc_dev *scu = dr->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
156  * sure the driver providing the IPC functionality cannot be unloaded
159  * Returns %NULL if SCU IPC is not currently available.
176 	dr->scu = scu;  in devm_intel_scu_ipc_dev_get()
184  * Send ipc command
188  * |rfu2(8) | size(8) | command id(4) | rfu1(3) | ioc(1) | command(8)|
192 	reinit_completion(&scu->cmd_complete);  in ipc_command()
193 	writel(cmd | IPC_IOC, scu->ipc_base);  in ipc_command()
197  * Write ipc data
198  * IPC Write Buffer (Write Only):
199  * 16-byte buffer for sending data associated with IPC command to
204 	writel(data, scu->ipc_base + IPC_WRITE_BUFFER + offset);  in ipc_data_writel()
209  * Driver will read this register to get the ready/busy status of the IPC
210  * block and error status of the IPC command that was just processed by SCU
216 	return __raw_readl(scu->ipc_base + IPC_STATUS);  in ipc_read_status()
219 /* Read ipc u32 data */
222 	return readl(scu->ipc_base + IPC_READ_BUFFER + offset);  in ipc_data_readl()
236 	return (status & IPC_STATUS_ERR) ? -EIO : 0;  in busy_loop()
239 /* Wait till ipc ioc interrupt is received or timeout in 10 HZ */
244 	wait_for_completion_timeout(&scu->cmd_complete, IPC_TIMEOUT);  in ipc_wait_for_interrupt()
248 		return -ETIMEDOUT;  in ipc_wait_for_interrupt()
251 		return -EIO;  in ipc_wait_for_interrupt()
258 	return scu->data.irq > 0 ? ipc_wait_for_interrupt(scu) : busy_loop(scu);  in intel_scu_ipc_check_status()
268 		return ERR_PTR(-ENODEV);  in intel_scu_ipc_get()
272 		dev_dbg(&scu->dev, "device is busy\n");  in intel_scu_ipc_get()
273 		return ERR_PTR(-EBUSY);  in intel_scu_ipc_get()
311 		ipc_command(scu, (count * 3) << 16 | id << 12 | 0 << 8 | op);  in pwr_reg_rdwr()
332  * intel_scu_ipc_dev_ioread8() - Read a byte via the SCU
333  * @scu: Optional SCU IPC instance
349  * intel_scu_ipc_dev_iowrite8() - Write a byte via the SCU
350  * @scu: Optional SCU IPC instance
366  * intel_scu_ipc_dev_readv() - Read a set of registers
367  * @scu: Optional SCU IPC instance
387  * intel_scu_ipc_dev_writev() - Write a set of registers
388  * @scu: Optional SCU IPC instance
408  * intel_scu_ipc_dev_update() - Update a register
409  * @scu: Optional SCU IPC instance
414  * Read-modify-write power control unit register. The first data argument
431  * intel_scu_ipc_dev_simple_command() - Send a simple command
432  * @scu: Optional SCU IPC instance
459 		dev_err(&scu->dev, "IPC command %#x failed with %d\n", cmdval, err);  in intel_scu_ipc_dev_simple_command()
465  * intel_scu_ipc_dev_command_with_size() - Command with data
466  * @scu: Optional SCU IPC instance
471  * @size: Input size written to the IPC command register in whatever
490 		return -EINVAL;  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()
531 	writel(status | IPC_STATUS_IRQ, scu->ipc_base + IPC_STATUS);  in ioc()
532 	complete(&scu->cmd_complete);  in ioc()
540 	struct intel_scu_ipc_data *data = &scu->data;  in intel_scu_ipc_release()
542 	if (data->irq > 0)  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()
545 	release_mem_region(data->mem.start, resource_size(&data->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.
572 	/* We support only one IPC */  in __intel_scu_ipc_register()
574 		return ERR_PTR(-EBUSY);  in __intel_scu_ipc_register()
578 		return ERR_PTR(-ENOMEM);  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()
588 	if (!request_mem_region(data->mem.start, resource_size(&data->mem), "intel_scu_ipc")) {  in __intel_scu_ipc_register()
589 		err = -EBUSY;  in __intel_scu_ipc_register()
593 	ipc_base = ioremap(data->mem.start, resource_size(&data->mem));  in __intel_scu_ipc_register()
595 		err = -ENOMEM;  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()
602 	if (data->irq > 0) {  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()
626 	release_mem_region(data->mem.start, resource_size(&data->mem));  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
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()
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.
688 	dr->scu = scu;  in __devm_intel_scu_ipc_register()