HID: intel-ish-hid: Move DMA disable code to new function

Add a new function ish_disable_dma() and move DMA disable operations
here, so that this functionality can be reused.

Signed-off-by: Even Xu <even.xu@intel.com>
Acked-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>

diff --git a/drivers/hid/intel-ish-hid/ipc/ipc.c b/drivers/hid/intel-ish-hid/ipc/ipc.c
index d4c5721..0e0dfa6 100644 (file)
--- a/drivers/hid/intel-ish-hid/ipc/ipc.c
+++ b/drivers/hid/intel-ish-hid/ipc/ipc.c
@@ -638,6 +638,36 @@ eoi:
 }
 
 /**
+ * ish_disable_dma() - disable dma communication between host and ISHFW
+ * @dev: ishtp device pointer
+ *
+ * Clear the dma enable bit and wait for dma inactive.
+ *
+ * Return: 0 for success else error code.
+ */
+static int ish_disable_dma(struct ishtp_device *dev)
+{
+       unsigned int    dma_delay;
+
+       /* Clear the dma enable bit */
+       ish_reg_write(dev, IPC_REG_ISH_RMP2, 0);
+
+       /* wait for dma inactive */
+       for (dma_delay = 0; dma_delay < MAX_DMA_DELAY &&
+               _ish_read_fw_sts_reg(dev) & (IPC_ISH_IN_DMA);
+               dma_delay += 5)
+               mdelay(5);
+
+       if (dma_delay >= MAX_DMA_DELAY) {
+               dev_err(dev->devc,
+                       "Wait for DMA inactive timeout\n");
+               return  -EBUSY;
+       }
+
+       return 0;
+}
+
+/**
  * ish_wakeup() - wakeup ishfw from waiting-for-host state
  * @dev: ishtp device pointer
  *
@@ -671,7 +701,6 @@ static int _ish_hw_reset(struct ishtp_device *dev)
 {
        struct pci_dev *pdev = dev->pdev;
        int     rv;
-       unsigned int    dma_delay;
        uint16_t csr;
 
        if (!pdev)
@@ -686,15 +715,8 @@ static int _ish_hw_reset(struct ishtp_device *dev)
                return  -EINVAL;
        }
 
-       /* Now trigger reset to FW */
-       ish_reg_write(dev, IPC_REG_ISH_RMP2, 0);
-
-       for (dma_delay = 0; dma_delay < MAX_DMA_DELAY &&
-               _ish_read_fw_sts_reg(dev) & (IPC_ISH_IN_DMA);
-               dma_delay += 5)
-               mdelay(5);
-
-       if (dma_delay >= MAX_DMA_DELAY) {
+       /* Disable dma communication between FW and host */
+       if (ish_disable_dma(dev)) {
                dev_err(&pdev->dev,
                        "Can't reset - stuck with DMA in-progress\n");
                return  -EBUSY;