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/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 0x9c 23 24 #define PCI_CSI_CONTROL 0xe8 25 #define PCI_CSI_CONTROL_PORTS_OFF_MASK 0x7 26 27 /* IOSF BT_MBI_UNIT_PMC regs */ 28 #define ISPSSPM0 0x39 29 #define ISPSSPM0_ISPSSC_OFFSET 0 30 #define ISPSSPM0_ISPSSC_MASK 0x00000003 31 #define ISPSSPM0_ISPSSS_OFFSET 24 32 #define ISPSSPM0_ISPSSS_MASK 0x03000000 33 #define ISPSSPM0_IUNIT_POWER_ON 0x0 34 #define ISPSSPM0_IUNIT_POWER_OFF 0x3 35 36 static 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 is 47 * 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 68 static 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 76 static void isp_remove(struct pci_dev *dev) 77 { 78 pm_runtime_get_sync(&dev->dev); 79 pm_runtime_forbid(&dev->dev); 80 } 81 82 static 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 island 91 * MRFLD HW design need all CSI ports are disabled before 92 * 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 gates 100 * the ISP. Can't use pci_set_power_state() because 101 * 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 } 109 110 static 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 } 120 121 static UNIVERSAL_DEV_PM_OPS(isp_pm_ops, isp_pci_suspend, 122 isp_pci_resume, NULL); 123 124 static const struct pci_device_id isp_id_table[] = { 125 { PCI_VDEVICE(INTEL, 0x0f38), }, 126 { PCI_VDEVICE(INTEL, 0x22b8), }, 127 { 0, } 128 }; 129 MODULE_DEVICE_TABLE(pci, isp_id_table); 130 131 static 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 }; 138 139 module_pci_driver(isp_pci_driver); 140 141 MODULE_DESCRIPTION("Intel AtomISP2 dummy / power-management drv (for suspend)"); 142 MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); 143 MODULE_LICENSE("GPL v2"); 144