1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * Dummy driver for Intel's Image Signal Processor found on Bay Trail 4 * and Cherry Trail devices. The sole purpose of this driver is to allow 5 * 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/pci.h> 17 #include <linux/pm_runtime.h> 18 #include <asm/iosf_mbi.h> 19 20 /* PCI configuration regs */ 21 #define PCI_INTERRUPT_CTRL 0x9c 22 23 #define PCI_CSI_CONTROL 0xe8 24 #define PCI_CSI_CONTROL_PORTS_OFF_MASK 0x7 25 26 /* IOSF BT_MBI_UNIT_PMC regs */ 27 #define ISPSSPM0 0x39 28 #define ISPSSPM0_ISPSSC_OFFSET 0 29 #define ISPSSPM0_ISPSSC_MASK 0x00000003 30 #define ISPSSPM0_ISPSSS_OFFSET 24 31 #define ISPSSPM0_ISPSSS_MASK 0x03000000 32 #define ISPSSPM0_IUNIT_POWER_ON 0x0 33 #define ISPSSPM0_IUNIT_POWER_OFF 0x3 34 35 static int isp_set_power(struct pci_dev *dev, bool enable) 36 { 37 unsigned long timeout; 38 u32 val = enable ? ISPSSPM0_IUNIT_POWER_ON : ISPSSPM0_IUNIT_POWER_OFF; 39 40 /* Write to ISPSSPM0 bit[1:0] to power on/off the IUNIT */ 41 iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0, 42 val, ISPSSPM0_ISPSSC_MASK); 43 44 /* 45 * There should be no IUNIT access while power-down is 46 * in progress. HW sighting: 4567865. 47 * Wait up to 50 ms for the IUNIT to shut down. 48 * And we do the same for power on. 49 */ 50 timeout = jiffies + msecs_to_jiffies(50); 51 do { 52 u32 tmp; 53 54 /* Wait until ISPSSPM0 bit[25:24] shows the right value */ 55 iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0, &tmp); 56 tmp = (tmp & ISPSSPM0_ISPSSS_MASK) >> ISPSSPM0_ISPSSS_OFFSET; 57 if (tmp == val) 58 return 0; 59 60 usleep_range(1000, 2000); 61 } while (time_before(jiffies, timeout)); 62 63 dev_err(&dev->dev, "IUNIT power-%s timeout.\n", enable ? "on" : "off"); 64 return -EBUSY; 65 } 66 67 static int isp_probe(struct pci_dev *dev, const struct pci_device_id *id) 68 { 69 pm_runtime_allow(&dev->dev); 70 pm_runtime_put_sync_suspend(&dev->dev); 71 72 return 0; 73 } 74 75 static void isp_remove(struct pci_dev *dev) 76 { 77 pm_runtime_get_sync(&dev->dev); 78 pm_runtime_forbid(&dev->dev); 79 } 80 81 static int isp_pci_suspend(struct device *dev) 82 { 83 struct pci_dev *pdev = to_pci_dev(dev); 84 u32 val; 85 86 pci_write_config_dword(pdev, PCI_INTERRUPT_CTRL, 0); 87 88 /* 89 * MRFLD IUNIT DPHY is located in an always-power-on island 90 * MRFLD HW design need all CSI ports are disabled before 91 * powering down the IUNIT. 92 */ 93 pci_read_config_dword(pdev, PCI_CSI_CONTROL, &val); 94 val |= PCI_CSI_CONTROL_PORTS_OFF_MASK; 95 pci_write_config_dword(pdev, PCI_CSI_CONTROL, val); 96 97 /* 98 * We lose config space access when punit power gates 99 * the ISP. Can't use pci_set_power_state() because 100 * pmcsr won't actually change when we write to it. 101 */ 102 pci_save_state(pdev); 103 pdev->current_state = PCI_D3cold; 104 isp_set_power(pdev, false); 105 106 return 0; 107 } 108 109 static int isp_pci_resume(struct device *dev) 110 { 111 struct pci_dev *pdev = to_pci_dev(dev); 112 113 isp_set_power(pdev, true); 114 pdev->current_state = PCI_D0; 115 pci_restore_state(pdev); 116 117 return 0; 118 } 119 120 static UNIVERSAL_DEV_PM_OPS(isp_pm_ops, isp_pci_suspend, 121 isp_pci_resume, NULL); 122 123 static const struct pci_device_id isp_id_table[] = { 124 { PCI_VDEVICE(INTEL, 0x0f38), }, 125 { PCI_VDEVICE(INTEL, 0x22b8), }, 126 { 0, } 127 }; 128 MODULE_DEVICE_TABLE(pci, isp_id_table); 129 130 static struct pci_driver isp_pci_driver = { 131 .name = "intel_atomisp2_pm", 132 .id_table = isp_id_table, 133 .probe = isp_probe, 134 .remove = isp_remove, 135 .driver.pm = &isp_pm_ops, 136 }; 137 138 module_pci_driver(isp_pci_driver); 139 140 MODULE_DESCRIPTION("Intel AtomISP2 dummy / power-management drv (for suspend)"); 141 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 142 MODULE_LICENSE("GPL v2"); 143