HID: intel-ish-hid: consolidate ish wake up operation

Same operations are done in ish_hw_start() and _ish_hw_reset() to
wakeup ISH device. Consolidate them by introducing a new function
ish_wakeup() and move the code there.
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>

drivers/hid/intel-ish-hid/ipc/ipc.c

@@ -637,6 +637,28 @@ irqreturn_t ish_irq_handler(int irq, void *dev_id)
 	return	IRQ_HANDLED;
 }
 
+/**
+ * ish_wakeup() - wakeup ishfw from waiting-for-host state
+ * @dev: ishtp device pointer
+ *
+ * Set the dma enable bit and send a void message to FW,
+ * it wil wakeup FW from waiting-for-host state.
+ */
+static void ish_wakeup(struct ishtp_device *dev)
+{
+	/* Set dma enable bit */
+	ish_reg_write(dev, IPC_REG_ISH_RMP2, IPC_RMP2_DMA_ENABLED);
+
+	/*
+	 * Send 0 IPC message so that ISH FW wakes up if it was already
+	 * asleep.
+	 */
+	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, IPC_DRBL_BUSY_BIT);
+
+	/* Flush writes to doorbell and REMAP2 */
+	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+}
+
 /**
  * _ish_hw_reset() - HW reset
  * @dev: ishtp device pointer
@@ -690,16 +712,8 @@ static int _ish_hw_reset(struct ishtp_device *dev)
 	csr |= PCI_D0;
 	pci_write_config_word(pdev, pdev->pm_cap + PCI_PM_CTRL, csr);
 
-	ish_reg_write(dev, IPC_REG_ISH_RMP2, IPC_RMP2_DMA_ENABLED);
-
-	/*
-	 * Send 0 IPC message so that ISH FW wakes up if it was already
-	 * asleep
-	 */
-	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, IPC_DRBL_BUSY_BIT);
-
-	/* Flush writes to doorbell and REMAP2 */
-	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+	/* Now we can enable ISH DMA operation and wakeup ISHFW */
+	ish_wakeup(dev);
 
 	return	0;
 }
@@ -758,16 +772,9 @@ static int _ish_ipc_reset(struct ishtp_device *dev)
 int ish_hw_start(struct ishtp_device *dev)
 {
 	ish_set_host_rdy(dev);
-	/* After that we can enable ISH DMA operation */
-	ish_reg_write(dev, IPC_REG_ISH_RMP2, IPC_RMP2_DMA_ENABLED);
 
-	/*
-	 * Send 0 IPC message so that ISH FW wakes up if it was already
-	 * asleep
-	 */
-	ish_reg_write(dev, IPC_REG_HOST2ISH_DRBL, IPC_DRBL_BUSY_BIT);
-	/* Flush write to doorbell */
-	ish_reg_read(dev, IPC_REG_ISH_HOST_FWSTS);
+	/* After that we can enable ISH DMA operation and wakeup ISHFW */
+	ish_wakeup(dev);
 
 	set_host_ready(dev);