intel_atomisp2_pm.c 3.7 KB

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