linux/drivers/platform/x86/intel_atomisp2_pm.c

149 lines
3.8 KiB
C

// SPDX-License-Identifier: GPL-2.0
/*
* Dummy driver for Intel's Image Signal Processor found on Bay 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);
while (1) {
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)
break;
if (time_after(jiffies, timeout)) {
dev_err(&dev->dev, "IUNIT power-%s timeout.\n",
enable ? "on" : "off");
return -EBUSY;
}
usleep_range(1000, 2000);
}
return 0;
}
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");