| Hans de Goede | 49ad712 | 2018-10-14 19:54:27 +0200 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0 |
| 2 | /* |
| 3 | * Dummy driver for Intel's Image Signal Processor found on Bay and Cherry |
| 4 | * Trail devices. The sole purpose of this driver is to allow the ISP to |
| 5 | * 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_probe(struct pci_dev *dev, const struct pci_device_id *id) |
| 37 | { |
| 38 | unsigned long timeout; |
| 39 | u32 val; |
| 40 | |
| 41 | pci_write_config_dword(dev, PCI_INTERRUPT_CTRL, 0); |
| 42 | |
| 43 | /* |
| 44 | * MRFLD IUNIT DPHY is located in an always-power-on island |
| 45 | * MRFLD HW design need all CSI ports are disabled before |
| 46 | * powering down the IUNIT. |
| 47 | */ |
| 48 | pci_read_config_dword(dev, PCI_CSI_CONTROL, &val); |
| 49 | val |= PCI_CSI_CONTROL_PORTS_OFF_MASK; |
| 50 | pci_write_config_dword(dev, PCI_CSI_CONTROL, val); |
| 51 | |
| 52 | /* Write 0x3 to ISPSSPM0 bit[1:0] to power off the IUNIT */ |
| 53 | iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0, |
| 54 | ISPSSPM0_IUNIT_POWER_OFF, ISPSSPM0_ISPSSC_MASK); |
| 55 | |
| 56 | /* |
| 57 | * There should be no IUNIT access while power-down is |
| 58 | * in progress HW sighting: 4567865 |
| 59 | * Wait up to 50 ms for the IUNIT to shut down. |
| 60 | */ |
| 61 | timeout = jiffies + msecs_to_jiffies(50); |
| 62 | while (1) { |
| 63 | /* Wait until ISPSSPM0 bit[25:24] shows 0x3 */ |
| 64 | iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0, &val); |
| 65 | val = (val & ISPSSPM0_ISPSSS_MASK) >> ISPSSPM0_ISPSSS_OFFSET; |
| 66 | if (val == ISPSSPM0_IUNIT_POWER_OFF) |
| 67 | break; |
| 68 | |
| 69 | if (time_after(jiffies, timeout)) { |
| 70 | dev_err(&dev->dev, "IUNIT power-off timeout.\n"); |
| 71 | return -EBUSY; |
| 72 | } |
| 73 | usleep_range(1000, 2000); |
| 74 | } |
| 75 | |
| 76 | pm_runtime_allow(&dev->dev); |
| 77 | pm_runtime_put_sync_suspend(&dev->dev); |
| 78 | |
| 79 | return 0; |
| 80 | } |
| 81 | |
| 82 | static void isp_remove(struct pci_dev *dev) |
| 83 | { |
| 84 | pm_runtime_get_sync(&dev->dev); |
| 85 | pm_runtime_forbid(&dev->dev); |
| 86 | } |
| 87 | |
| 88 | static int isp_pci_suspend(struct device *dev) |
| 89 | { |
| 90 | return 0; |
| 91 | } |
| 92 | |
| 93 | static int isp_pci_resume(struct device *dev) |
| 94 | { |
| 95 | return 0; |
| 96 | } |
| 97 | |
| 98 | static UNIVERSAL_DEV_PM_OPS(isp_pm_ops, isp_pci_suspend, |
| 99 | isp_pci_resume, NULL); |
| 100 | |
| 101 | static const struct pci_device_id isp_id_table[] = { |
| 102 | { PCI_VDEVICE(INTEL, 0x22b8), }, |
| 103 | { 0, } |
| 104 | }; |
| 105 | MODULE_DEVICE_TABLE(pci, isp_id_table); |
| 106 | |
| 107 | static struct pci_driver isp_pci_driver = { |
| 108 | .name = "intel_atomisp2_pm", |
| 109 | .id_table = isp_id_table, |
| 110 | .probe = isp_probe, |
| 111 | .remove = isp_remove, |
| 112 | .driver.pm = &isp_pm_ops, |
| 113 | }; |
| 114 | |
| 115 | module_pci_driver(isp_pci_driver); |
| 116 | |
| 117 | MODULE_DESCRIPTION("Intel AtomISP2 dummy / power-management drv (for suspend)"); |
| 118 | MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); |
| 119 | MODULE_LICENSE("GPL v2"); |