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
isp_set_power(struct pci_dev * dev,bool enable)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
isp_probe(struct pci_dev * dev,const struct pci_device_id * id)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
isp_remove(struct pci_dev * dev)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
isp_pci_suspend(struct device * dev)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
isp_pci_resume(struct device * dev)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