1 files changed, 119 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..9371603a0ac9
--- /dev/null
+++ b/drivers/platform/x86/intel_atomisp2_pm.c
@@ -0,0 +1,119 @@
+// 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_probe(struct pci_dev *dev, const struct pci_device_id *id)
+{
+        unsigned long timeout;
+        u32 val;
+
+        pci_write_config_dword(dev, 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(dev, PCI_CSI_CONTROL, &val);
+        val |= PCI_CSI_CONTROL_PORTS_OFF_MASK;
+        pci_write_config_dword(dev, PCI_CSI_CONTROL, val);
+
+        /* Write 0x3 to ISPSSPM0 bit[1:0] to power off the IUNIT */
+        iosf_mbi_modify(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0,
+                        ISPSSPM0_IUNIT_POWER_OFF, 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.
+         */
+        timeout = jiffies + msecs_to_jiffies(50);
+        while (1) {
+                /* Wait until ISPSSPM0 bit[25:24] shows 0x3 */
+                iosf_mbi_read(BT_MBI_UNIT_PMC, MBI_REG_READ, ISPSSPM0, &val);
+                val = (val & ISPSSPM0_ISPSSS_MASK) >> ISPSSPM0_ISPSSS_OFFSET;
+                if (val == ISPSSPM0_IUNIT_POWER_OFF)
+                        break;
+
+                if (time_after(jiffies, timeout)) {
+                        dev_err(&dev->dev, "IUNIT power-off timeout.\n");
+                        return -EBUSY;
+                }
+                usleep_range(1000, 2000);
+        }
+
+        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)
+{
+        return 0;
+}
+
+static int isp_pci_resume(struct device *dev)
+{
+        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, 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");