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1// SPDX-License-Identifier: GPL-2.02/*3 * Dummy driver for Intel's Image Signal Processor found on Bay Trail4 * and Cherry Trail devices. The sole purpose of this driver is to allow5 * the ISP to be put in D3.6 *7 * Copyright (C) 2018 Hans de Goede <hdegoede@redhat.com>8 *9 * Based on various non upstream patches for ISP support:10 * Copyright (C) 2010-2017 Intel Corporation. All rights reserved.11 * Copyright (c) 2010 Silicon Hive www.siliconhive.com.12 */13 14#include <linux/delay.h>15#include <linux/module.h>16#include <linux/mod_devicetable.h>17#include <linux/pci.h>18#include <linux/pm_runtime.h>19#include <asm/iosf_mbi.h>20 21/* PCI configuration regs */22#define PCI_INTERRUPT_CTRL 0x9c23 24#define PCI_CSI_CONTROL 0xe825#define PCI_CSI_CONTROL_PORTS_OFF_MASK 0x726 27/* IOSF BT_MBI_UNIT_PMC regs */28#define ISPSSPM0 0x3929#define ISPSSPM0_ISPSSC_OFFSET 030#define ISPSSPM0_ISPSSC_MASK 0x0000000331#define ISPSSPM0_ISPSSS_OFFSET 2432#define ISPSSPM0_ISPSSS_MASK 0x0300000033#define ISPSSPM0_IUNIT_POWER_ON 0x034#define ISPSSPM0_IUNIT_POWER_OFF 0x335 36static int isp_set_power(struct pci_dev *dev, bool enable)37{38 unsigned long timeout;39 u32 val = enable ? ISPSSPM0_IUNIT_POWER_ON : ISPSSPM0_IUNIT_POWER_OFF;40 41 /* Write to ISPSSPM0 bit[1:0] to power on/off the IUNIT */42 iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0,43 val, ISPSSPM0_ISPSSC_MASK);44 45 /*46 * There should be no IUNIT access while power-down is47 * in progress. HW sighting: 4567865.48 * Wait up to 50 ms for the IUNIT to shut down.49 * And we do the same for power on.50 */51 timeout = jiffies + msecs_to_jiffies(50);52 do {53 u32 tmp;54 55 /* Wait until ISPSSPM0 bit[25:24] shows the right value */56 iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0, &tmp);57 tmp = (tmp & ISPSSPM0_ISPSSS_MASK) >> ISPSSPM0_ISPSSS_OFFSET;58 if (tmp == val)59 return 0;60 61 usleep_range(1000, 2000);62 } while (time_before(jiffies, timeout));63 64 dev_err(&dev->dev, "IUNIT power-%s timeout.\n", enable ? "on" : "off");65 return -EBUSY;66}67 68static int isp_probe(struct pci_dev *dev, const struct pci_device_id *id)69{70 pm_runtime_allow(&dev->dev);71 pm_runtime_put_sync_suspend(&dev->dev);72 73 return 0;74}75 76static void isp_remove(struct pci_dev *dev)77{78 pm_runtime_get_sync(&dev->dev);79 pm_runtime_forbid(&dev->dev);80}81 82static int isp_pci_suspend(struct device *dev)83{84 struct pci_dev *pdev = to_pci_dev(dev);85 u32 val;86 87 pci_write_config_dword(pdev, PCI_INTERRUPT_CTRL, 0);88 89 /*90 * MRFLD IUNIT DPHY is located in an always-power-on island91 * MRFLD HW design need all CSI ports are disabled before92 * powering down the IUNIT.93 */94 pci_read_config_dword(pdev, PCI_CSI_CONTROL, &val);95 val |= PCI_CSI_CONTROL_PORTS_OFF_MASK;96 pci_write_config_dword(pdev, PCI_CSI_CONTROL, val);97 98 /*99 * We lose config space access when punit power gates100 * the ISP. Can't use pci_set_power_state() because101 * pmcsr won't actually change when we write to it.102 */103 pci_save_state(pdev);104 pdev->current_state = PCI_D3cold;105 isp_set_power(pdev, false);106 107 return 0;108}109 110static int isp_pci_resume(struct device *dev)111{112 struct pci_dev *pdev = to_pci_dev(dev);113 114 isp_set_power(pdev, true);115 pdev->current_state = PCI_D0;116 pci_restore_state(pdev);117 118 return 0;119}120 121static UNIVERSAL_DEV_PM_OPS(isp_pm_ops, isp_pci_suspend,122 isp_pci_resume, NULL);123 124static const struct pci_device_id isp_id_table[] = {125 { PCI_VDEVICE(INTEL, 0x0f38), },126 { PCI_VDEVICE(INTEL, 0x22b8), },127 { 0, }128};129MODULE_DEVICE_TABLE(pci, isp_id_table);130 131static struct pci_driver isp_pci_driver = {132 .name = "intel_atomisp2_pm",133 .id_table = isp_id_table,134 .probe = isp_probe,135 .remove = isp_remove,136 .driver.pm = &isp_pm_ops,137};138 139module_pci_driver(isp_pci_driver);140 141MODULE_DESCRIPTION("Intel AtomISP2 dummy / power-management drv (for suspend)");142MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>");143MODULE_LICENSE("GPL v2");144