ath10k: enable bus layer suspend/resume for WCN3990

Register snoc bus layer suspend/resume PM ops and configure
the wakeup source(CE2) for the device.

Testing:
    Tested on WCN3990 HW.
    Tested FW: WLAN.HL.2.0-01192-QCAHLSWMTPLZ-1.
Signed-off-by: Govind Singh <govinds@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ath/ath10k/snoc.c

@@ -30,6 +30,7 @@
 
 #define ATH10K_SNOC_RX_POST_RETRY_MS 50
 #define CE_POLL_PIPE 4
+#define ATH10K_SNOC_WAKE_IRQ 2
 
 static char *const ce_name[] = {
 	"WLAN_CE_0",
@@ -1048,6 +1049,46 @@ static int ath10k_snoc_hif_power_up(struct ath10k *ar)
 	return ret;
 }
 
+#ifdef CONFIG_PM
+static int ath10k_snoc_hif_suspend(struct ath10k *ar)
+{
+	struct ath10k_snoc *ar_snoc = ath10k_snoc_priv(ar);
+	int ret;
+
+	if (!device_may_wakeup(ar->dev))
+		return -EPERM;
+
+	ret = enable_irq_wake(ar_snoc->ce_irqs[ATH10K_SNOC_WAKE_IRQ].irq_line);
+	if (ret) {
+		ath10k_err(ar, "failed to enable wakeup irq :%d\n", ret);
+		return ret;
+	}
+
+	ath10k_dbg(ar, ATH10K_DBG_SNOC, "snoc device suspended\n");
+
+	return ret;
+}
+
+static int ath10k_snoc_hif_resume(struct ath10k *ar)
+{
+	struct ath10k_snoc *ar_snoc = ath10k_snoc_priv(ar);
+	int ret;
+
+	if (!device_may_wakeup(ar->dev))
+		return -EPERM;
+
+	ret = disable_irq_wake(ar_snoc->ce_irqs[ATH10K_SNOC_WAKE_IRQ].irq_line);
+	if (ret) {
+		ath10k_err(ar, "failed to disable wakeup irq: %d\n", ret);
+		return ret;
+	}
+
+	ath10k_dbg(ar, ATH10K_DBG_SNOC, "snoc device resumed\n");
+
+	return ret;
+}
+#endif
+
 static const struct ath10k_hif_ops ath10k_snoc_hif_ops = {
 	.read32		= ath10k_snoc_read32,
 	.write32	= ath10k_snoc_write32,
@@ -1061,6 +1102,10 @@ static const struct ath10k_hif_ops ath10k_snoc_hif_ops = {
 	.send_complete_check	= ath10k_snoc_hif_send_complete_check,
 	.get_free_queue_number	= ath10k_snoc_hif_get_free_queue_number,
 	.get_target_info	= ath10k_snoc_hif_get_target_info,
+#ifdef CONFIG_PM
+	.suspend                = ath10k_snoc_hif_suspend,
+	.resume                 = ath10k_snoc_hif_resume,
+#endif
 };
 
 static const struct ath10k_bus_ops ath10k_snoc_bus_ops = {