HID: intel-ish-hid: ipc: check FW status to distinguish ISH resume paths

For ISH resume, there are two paths, they need different way to handle: one
where ISH is not powered off, in that case a simple resume message is enough,
in other case we need a reset sequence.

We can use ISH FW status to distinguish those two cases and handle them
properly.

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/hw-ish-regs.h

@@ -110,6 +110,14 @@
 #define IPC_ILUP_OFFS			(0)
 #define IPC_ILUP_BIT			(1<<IPC_ILUP_OFFS)
 
+/*
+ * ISH FW status bits in ISH FW Status Register
+ */
+#define IPC_ISH_FWSTS_SHIFT		12
+#define IPC_ISH_FWSTS_MASK		GENMASK(15, 12)
+#define IPC_GET_ISH_FWSTS(status)	\
+	(((status) & IPC_ISH_FWSTS_MASK) >> IPC_ISH_FWSTS_SHIFT)
+
 /*
  * FW status bits (relevant)
  */

drivers/hid/intel-ish-hid/ipc/hw-ish.h

@@ -61,6 +61,18 @@ struct ish_hw {
 	void __iomem *mem_addr;
 };
 
+/*
+ * ISH FW status type
+ */
+enum {
+	FWSTS_AFTER_RESET		= 0,
+	FWSTS_WAIT_FOR_HOST		= 4,
+	FWSTS_START_KERNEL_DMA		= 5,
+	FWSTS_FW_IS_RUNNING		= 7,
+	FWSTS_SENSOR_APP_LOADED		= 8,
+	FWSTS_SENSOR_APP_RUNNING	= 15
+};
+
 #define to_ish_hw(dev) (struct ish_hw *)((dev)->hw)
 
 irqreturn_t ish_irq_handler(int irq, void *dev_id);

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

@@ -206,33 +206,47 @@ static void ish_remove(struct pci_dev *pdev)
 #ifdef CONFIG_PM
 static struct device *ish_resume_device;
 
+/* 50ms to get resume response */
+#define WAIT_FOR_RESUME_ACK_MS		50
+
 /**
  * ish_resume_handler() - Work function to complete resume
  * @work:	work struct
  *
  * The resume work function to complete resume function asynchronously.
- * There are two types of platforms, one where ISH is not powered off,
+ * There are two resume paths, one where ISH is not powered off,
  * in that case a simple resume message is enough, others we need
  * a reset sequence.
  */
 static void ish_resume_handler(struct work_struct *work)
 {
 	struct pci_dev *pdev = to_pci_dev(ish_resume_device);
 	struct ishtp_device *dev = pci_get_drvdata(pdev);
+	uint32_t fwsts;
 	int ret;
 
-	ishtp_send_resume(dev);
+	/* Get ISH FW status */
+	fwsts = IPC_GET_ISH_FWSTS(dev->ops->get_fw_status(dev));
 
-	/* 50 ms to get resume response */
-	if (dev->resume_flag)
-		ret = wait_event_interruptible_timeout(dev->resume_wait,
-						       !dev->resume_flag,
-						       msecs_to_jiffies(50));
+	/*
+	 * If currently, in ISH FW, sensor app is loaded or beyond that,
+	 * it means ISH isn't powered off, in this case, send a resume message.
+	 */
+	if (fwsts >= FWSTS_SENSOR_APP_LOADED) {
+		ishtp_send_resume(dev);
+
+		/* Waiting to get resume response */
+		if (dev->resume_flag)
+			ret = wait_event_interruptible_timeout(dev->resume_wait,
+				!dev->resume_flag,
+				msecs_to_jiffies(WAIT_FOR_RESUME_ACK_MS));
+	}
 
 	/*
-	 * If no resume response. This platform  is not S0ix compatible
-	 * So on resume full reboot of ISH processor will happen, so
-	 * need to go through init sequence again
+	 * If in ISH FW, sensor app isn't loaded yet, or no resume response.
+	 * That means this platform is not S0ix compatible, or something is
+	 * wrong with ISH FW. So on resume, full reboot of ISH processor will
+	 * happen, so need to go through init sequence again.
 	 */
 	if (dev->resume_flag)
 		ish_init(dev);