144 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			144 lines
		
	
	
		
			3.7 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
// SPDX-License-Identifier: GPL-2.0
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/*
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 * Dummy driver for Intel's Image Signal Processor found on Bay Trail
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 * and Cherry Trail devices. The sole purpose of this driver is to allow
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 * the ISP to be put in D3.
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 *
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 * Copyright (C) 2018 Hans de Goede <hdegoede@redhat.com>
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 *
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 * Based on various non upstream patches for ISP support:
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 * Copyright (C) 2010-2017 Intel Corporation. All rights reserved.
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 * Copyright (c) 2010 Silicon Hive www.siliconhive.com.
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 */
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#include <linux/delay.h>
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#include <linux/module.h>
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#include <linux/mod_devicetable.h>
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#include <linux/pci.h>
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#include <linux/pm_runtime.h>
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#include <asm/iosf_mbi.h>
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/* PCI configuration regs */
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#define PCI_INTERRUPT_CTRL		0x9c
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#define PCI_CSI_CONTROL			0xe8
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#define PCI_CSI_CONTROL_PORTS_OFF_MASK	0x7
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/* IOSF BT_MBI_UNIT_PMC regs */
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#define ISPSSPM0			0x39
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#define ISPSSPM0_ISPSSC_OFFSET		0
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#define ISPSSPM0_ISPSSC_MASK		0x00000003
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#define ISPSSPM0_ISPSSS_OFFSET		24
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#define ISPSSPM0_ISPSSS_MASK		0x03000000
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#define ISPSSPM0_IUNIT_POWER_ON		0x0
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#define ISPSSPM0_IUNIT_POWER_OFF	0x3
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static int isp_set_power(struct pci_dev *dev, bool enable)
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{
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	unsigned long timeout;
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	u32 val = enable ? ISPSSPM0_IUNIT_POWER_ON : ISPSSPM0_IUNIT_POWER_OFF;
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	/* Write to ISPSSPM0 bit[1:0] to power on/off the IUNIT */
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	iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0,
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			val, ISPSSPM0_ISPSSC_MASK);
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	/*
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	 * There should be no IUNIT access while power-down is
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	 * in progress. HW sighting: 4567865.
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	 * Wait up to 50 ms for the IUNIT to shut down.
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	 * And we do the same for power on.
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	 */
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	timeout = jiffies + msecs_to_jiffies(50);
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	do {
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		u32 tmp;
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		/* Wait until ISPSSPM0 bit[25:24] shows the right value */
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		iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0, &tmp);
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		tmp = (tmp & ISPSSPM0_ISPSSS_MASK) >> ISPSSPM0_ISPSSS_OFFSET;
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		if (tmp == val)
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			return 0;
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		usleep_range(1000, 2000);
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	} while (time_before(jiffies, timeout));
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	dev_err(&dev->dev, "IUNIT power-%s timeout.\n", enable ? "on" : "off");
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	return -EBUSY;
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}
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static int isp_probe(struct pci_dev *dev, const struct pci_device_id *id)
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{
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	pm_runtime_allow(&dev->dev);
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	pm_runtime_put_sync_suspend(&dev->dev);
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	return 0;
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}
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static void isp_remove(struct pci_dev *dev)
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{
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	pm_runtime_get_sync(&dev->dev);
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	pm_runtime_forbid(&dev->dev);
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}
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static int isp_pci_suspend(struct device *dev)
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{
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	struct pci_dev *pdev = to_pci_dev(dev);
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	u32 val;
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	pci_write_config_dword(pdev, PCI_INTERRUPT_CTRL, 0);
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	/*
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	 * MRFLD IUNIT DPHY is located in an always-power-on island
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	 * MRFLD HW design need all CSI ports are disabled before
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	 * powering down the IUNIT.
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	 */
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	pci_read_config_dword(pdev, PCI_CSI_CONTROL, &val);
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	val |= PCI_CSI_CONTROL_PORTS_OFF_MASK;
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	pci_write_config_dword(pdev, PCI_CSI_CONTROL, val);
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	/*
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	 * We lose config space access when punit power gates
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	 * the ISP. Can't use pci_set_power_state() because
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	 * pmcsr won't actually change when we write to it.
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	 */
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	pci_save_state(pdev);
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	pdev->current_state = PCI_D3cold;
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	isp_set_power(pdev, false);
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	return 0;
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}
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static int isp_pci_resume(struct device *dev)
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{
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	struct pci_dev *pdev = to_pci_dev(dev);
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	isp_set_power(pdev, true);
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	pdev->current_state = PCI_D0;
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	pci_restore_state(pdev);
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	return 0;
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}
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static UNIVERSAL_DEV_PM_OPS(isp_pm_ops, isp_pci_suspend,
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			    isp_pci_resume, NULL);
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static const struct pci_device_id isp_id_table[] = {
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	{ PCI_VDEVICE(INTEL, 0x0f38), },
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	{ PCI_VDEVICE(INTEL, 0x22b8), },
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	{ 0, }
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};
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MODULE_DEVICE_TABLE(pci, isp_id_table);
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static struct pci_driver isp_pci_driver = {
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	.name = "intel_atomisp2_pm",
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	.id_table = isp_id_table,
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	.probe = isp_probe,
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	.remove = isp_remove,
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	.driver.pm = &isp_pm_ops,
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};
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module_pci_driver(isp_pci_driver);
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MODULE_DESCRIPTION("Intel AtomISP2 dummy / power-management drv (for suspend)");
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MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");
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MODULE_LICENSE("GPL v2");
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