diff options
Diffstat (limited to 'drivers/platform/x86/intel/atomisp2/pm.c')
| -rw-r--r-- | drivers/platform/x86/intel/atomisp2/pm.c | 143 |
1 files changed, 143 insertions, 0 deletions
diff --git a/drivers/platform/x86/intel/atomisp2/pm.c b/drivers/platform/x86/intel/atomisp2/pm.c new file mode 100644 index 000000000000..805fc0d8515c --- /dev/null +++ b/drivers/platform/x86/intel/atomisp2/pm.c @@ -0,0 +1,143 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Dummy driver for Intel's Image Signal Processor found on Bay Trail + * and Cherry Trail devices. The sole purpose of this driver is to allow + * the ISP to be put in D3. + * + * Copyright (C) 2018 Hans de Goede <hdegoede@redhat.com> + * + * Based on various non upstream patches for ISP support: + * Copyright (C) 2010-2017 Intel Corporation. All rights reserved. + * Copyright (c) 2010 Silicon Hive www.siliconhive.com. + */ + +#include <linux/delay.h> +#include <linux/module.h> +#include <linux/mod_devicetable.h> +#include <linux/pci.h> +#include <linux/pm_runtime.h> +#include <asm/iosf_mbi.h> + +/* PCI configuration regs */ +#define PCI_INTERRUPT_CTRL 0x9c + +#define PCI_CSI_CONTROL 0xe8 +#define PCI_CSI_CONTROL_PORTS_OFF_MASK 0x7 + +/* IOSF BT_MBI_UNIT_PMC regs */ +#define ISPSSPM0 0x39 +#define ISPSSPM0_ISPSSC_OFFSET 0 +#define ISPSSPM0_ISPSSC_MASK 0x00000003 +#define ISPSSPM0_ISPSSS_OFFSET 24 +#define ISPSSPM0_ISPSSS_MASK 0x03000000 +#define ISPSSPM0_IUNIT_POWER_ON 0x0 +#define ISPSSPM0_IUNIT_POWER_OFF 0x3 + +static int isp_set_power(struct pci_dev *dev, bool enable) +{ + unsigned long timeout; + u32 val = enable ? ISPSSPM0_IUNIT_POWER_ON : ISPSSPM0_IUNIT_POWER_OFF; + + /* Write to ISPSSPM0 bit[1:0] to power on/off the IUNIT */ + iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0, + val, ISPSSPM0_ISPSSC_MASK); + + /* + * There should be no IUNIT access while power-down is + * in progress. HW sighting: 4567865. + * Wait up to 50 ms for the IUNIT to shut down. + * And we do the same for power on. + */ + timeout = jiffies + msecs_to_jiffies(50); + do { + u32 tmp; + + /* Wait until ISPSSPM0 bit[25:24] shows the right value */ + iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0, &tmp); + tmp = (tmp & ISPSSPM0_ISPSSS_MASK) >> ISPSSPM0_ISPSSS_OFFSET; + if (tmp == val) + return 0; + + usleep_range(1000, 2000); + } while (time_before(jiffies, timeout)); + + dev_err(&dev->dev, "IUNIT power-%s timeout.\n", enable ? "on" : "off"); + return -EBUSY; +} + +static int isp_probe(struct pci_dev *dev, const struct pci_device_id *id) +{ + pm_runtime_allow(&dev->dev); + pm_runtime_put_sync_suspend(&dev->dev); + + return 0; +} + +static void isp_remove(struct pci_dev *dev) +{ + pm_runtime_get_sync(&dev->dev); + pm_runtime_forbid(&dev->dev); +} + +static int isp_pci_suspend(struct device *dev) +{ + struct pci_dev *pdev = to_pci_dev(dev); + u32 val; + + pci_write_config_dword(pdev, PCI_INTERRUPT_CTRL, 0); + + /* + * MRFLD IUNIT DPHY is located in an always-power-on island + * MRFLD HW design need all CSI ports are disabled before + * powering down the IUNIT. + */ + pci_read_config_dword(pdev, PCI_CSI_CONTROL, &val); + val |= PCI_CSI_CONTROL_PORTS_OFF_MASK; + pci_write_config_dword(pdev, PCI_CSI_CONTROL, val); + + /* + * We lose config space access when punit power gates + * the ISP. Can't use pci_set_power_state() because + * pmcsr won't actually change when we write to it. + */ + pci_save_state(pdev); + pdev->current_state = PCI_D3cold; + isp_set_power(pdev, false); + + return 0; +} + +static int isp_pci_resume(struct device *dev) +{ + struct pci_dev *pdev = to_pci_dev(dev); + + isp_set_power(pdev, true); + pdev->current_state = PCI_D0; + pci_restore_state(pdev); + + return 0; +} + +static UNIVERSAL_DEV_PM_OPS(isp_pm_ops, isp_pci_suspend, + isp_pci_resume, NULL); + +static const struct pci_device_id isp_id_table[] = { + { PCI_VDEVICE(INTEL, 0x0f38), }, + { PCI_VDEVICE(INTEL, 0x22b8), }, + { 0, } +}; +MODULE_DEVICE_TABLE(pci, isp_id_table); + +static struct pci_driver isp_pci_driver = { + .name = "intel_atomisp2_pm", + .id_table = isp_id_table, + .probe = isp_probe, + .remove = isp_remove, + .driver.pm = &isp_pm_ops, +}; + +module_pci_driver(isp_pci_driver); + +MODULE_DESCRIPTION("Intel AtomISP2 dummy / power-management drv (for suspend)"); +MODULE_AUTHOR("Hans de Goede <hdegoede@redhat.com>"); +MODULE_LICENSE("GPL v2"); |