i2c: i801: Drop needless bit-wise OR

[cascardo/linux.git] / drivers / i2c / busses / i2c-i801.c

diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
index 64b1208..b436963 100644 (file)
--- a/drivers/i2c/busses/i2c-i801.c
+++ b/drivers/i2c/busses/i2c-i801.c
@@ -245,6 +245,13 @@ struct i801_priv {
        struct platform_device *mux_pdev;
 #endif
        struct platform_device *tco_pdev;
+
+       /*
+        * If set to true the host controller registers are reserved for
+        * ACPI AML use. Protected by acpi_lock.
+        */
+       bool acpi_reserved;
+       struct mutex acpi_lock;
 };
 
 #define FEATURE_SMBUS_PEC      (1 << 0)
@@ -540,7 +547,7 @@ static irqreturn_t i801_isr(int irq, void *dev_id)
        status &= SMBHSTSTS_INTR | STATUS_ERROR_FLAGS;
        if (status) {
                outb_p(status, SMBHSTSTS(priv));
-               priv->status |= status;
+               priv->status = status;
                wake_up(&priv->waitq);
        }
 
@@ -718,6 +725,12 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr,
        int ret = 0, xact = 0;
        struct i801_priv *priv = i2c_get_adapdata(adap);
 
+       mutex_lock(&priv->acpi_lock);
+       if (priv->acpi_reserved) {
+               mutex_unlock(&priv->acpi_lock);
+               return -EBUSY;
+       }
+
        pm_runtime_get_sync(&priv->pci_dev->dev);
 
        hwpec = (priv->features & FEATURE_SMBUS_PEC) && (flags & I2C_CLIENT_PEC)
@@ -820,6 +833,7 @@ static s32 i801_access(struct i2c_adapter *adap, u16 addr,
 out:
        pm_runtime_mark_last_busy(&priv->pci_dev->dev);
        pm_runtime_put_autosuspend(&priv->pci_dev->dev);
+       mutex_unlock(&priv->acpi_lock);
        return ret;
 }
 
@@ -1257,6 +1271,83 @@ static void i801_add_tco(struct i801_priv *priv)
        priv->tco_pdev = pdev;
 }
 
+#ifdef CONFIG_ACPI
+static acpi_status
+i801_acpi_io_handler(u32 function, acpi_physical_address address, u32 bits,
+                    u64 *value, void *handler_context, void *region_context)
+{
+       struct i801_priv *priv = handler_context;
+       struct pci_dev *pdev = priv->pci_dev;
+       acpi_status status;
+
+       /*
+        * Once BIOS AML code touches the OpRegion we warn and inhibit any
+        * further access from the driver itself. This device is now owned
+        * by the system firmware.
+        */
+       mutex_lock(&priv->acpi_lock);
+
+       if (!priv->acpi_reserved) {
+               priv->acpi_reserved = true;
+
+               dev_warn(&pdev->dev, "BIOS is accessing SMBus registers\n");
+               dev_warn(&pdev->dev, "Driver SMBus register access inhibited\n");
+
+               /*
+                * BIOS is accessing the host controller so prevent it from
+                * suspending automatically from now on.
+                */
+               pm_runtime_get_sync(&pdev->dev);
+       }
+
+       if ((function & ACPI_IO_MASK) == ACPI_READ)
+               status = acpi_os_read_port(address, (u32 *)value, bits);
+       else
+               status = acpi_os_write_port(address, (u32)*value, bits);
+
+       mutex_unlock(&priv->acpi_lock);
+
+       return status;
+}
+
+static int i801_acpi_probe(struct i801_priv *priv)
+{
+       struct acpi_device *adev;
+       acpi_status status;
+
+       adev = ACPI_COMPANION(&priv->pci_dev->dev);
+       if (adev) {
+               status = acpi_install_address_space_handler(adev->handle,
+                               ACPI_ADR_SPACE_SYSTEM_IO, i801_acpi_io_handler,
+                               NULL, priv);
+               if (ACPI_SUCCESS(status))
+                       return 0;
+       }
+
+       return acpi_check_resource_conflict(&priv->pci_dev->resource[SMBBAR]);
+}
+
+static void i801_acpi_remove(struct i801_priv *priv)
+{
+       struct acpi_device *adev;
+
+       adev = ACPI_COMPANION(&priv->pci_dev->dev);
+       if (!adev)
+               return;
+
+       acpi_remove_address_space_handler(adev->handle,
+               ACPI_ADR_SPACE_SYSTEM_IO, i801_acpi_io_handler);
+
+       mutex_lock(&priv->acpi_lock);
+       if (priv->acpi_reserved)
+               pm_runtime_put(&priv->pci_dev->dev);
+       mutex_unlock(&priv->acpi_lock);
+}
+#else
+static inline int i801_acpi_probe(struct i801_priv *priv) { return 0; }
+static inline void i801_acpi_remove(struct i801_priv *priv) { }
+#endif
+
 static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
 {
        unsigned char temp;
@@ -1274,6 +1365,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
        priv->adapter.dev.parent = &dev->dev;
        ACPI_COMPANION_SET(&priv->adapter.dev, ACPI_COMPANION(&dev->dev));
        priv->adapter.retries = 3;
+       mutex_init(&priv->acpi_lock);
 
        priv->pci_dev = dev;
        switch (dev->device) {
@@ -1336,10 +1428,8 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
                return -ENODEV;
        }
 
-       err = acpi_check_resource_conflict(&dev->resource[SMBBAR]);
-       if (err) {
+       if (i801_acpi_probe(priv))
                return -ENODEV;
-       }
 
        err = pcim_iomap_regions(dev, 1 << SMBBAR,
                                 dev_driver_string(&dev->dev));
@@ -1348,6 +1438,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
                        "Failed to request SMBus region 0x%lx-0x%Lx\n",
                        priv->smba,
                        (unsigned long long)pci_resource_end(dev, SMBBAR));
+               i801_acpi_remove(priv);
                return err;
        }
 
@@ -1412,6 +1503,7 @@ static int i801_probe(struct pci_dev *dev, const struct pci_device_id *id)
        err = i2c_add_adapter(&priv->adapter);
        if (err) {
                dev_err(&dev->dev, "Failed to add SMBus adapter\n");
+               i801_acpi_remove(priv);
                return err;
        }
 
@@ -1438,6 +1530,7 @@ static void i801_remove(struct pci_dev *dev)
 
        i801_del_mux(priv);
        i2c_del_adapter(&priv->adapter);
+       i801_acpi_remove(priv);
        pci_write_config_byte(dev, SMBHSTCFG, priv->original_hstcfg);
 
        platform_device_unregister(priv->tco_pdev);