ath11k: implement suspend for QCA6390 PCI devices

Now that all the needed pieces are in place implement suspend support QCA6390
PCI devices. All other devices will return -EOPNOTSUPP during suspend. The
suspend is implemented by switching the firmware to WoW mode during suspend, so
the firmware will be running on low power mode while host is in suspend.

At the moment we are not able to shutdown and fully power off the device due to
bugs in MHI subsystem, so WoW mode is a workaround for the time being.

During suspend we enable WoW mode, disable CE irq and DP irq, then put MHI to
suspend state.  During resume, driver resumes MHI firstly, then enables CE irq
and dp IRQ, and sends WoW wakeup command to firmware.

Tested-on: QCA6390 hw2.0 PCI WLAN.HST.1.0.1-01740-QCAHSTSWPLZ_V2_TO_X86-1
Signed-off-by: Carl Huang <cjhuang@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1607708150-21066-11-git-send-email-kvalo@codeaurora.org

drivers/net/wireless/ath/ath11k/ce.c

@@ -195,7 +195,7 @@ static bool ath11k_ce_need_shadow_fix(int ce_id)
 	return false;
 }
 
-static void ath11k_ce_stop_shadow_timers(struct ath11k_base *ab)
+void ath11k_ce_stop_shadow_timers(struct ath11k_base *ab)
 {
 	int i;
 

drivers/net/wireless/ath/ath11k/ce.h

@@ -190,4 +190,6 @@ int ath11k_ce_map_service_to_pipe(struct ath11k_base *ab, u16 service_id,
 int ath11k_ce_attr_attach(struct ath11k_base *ab);
 void ath11k_ce_get_shadow_config(struct ath11k_base *ab,
 				 u32 **shadow_cfg, u32 *shadow_cfg_len);
+void ath11k_ce_stop_shadow_timers(struct ath11k_base *ab);
+
 #endif

drivers/net/wireless/ath/ath11k/core.c

@@ -13,6 +13,7 @@
 #include "dp_rx.h"
 #include "debug.h"
 #include "hif.h"
+#include "wow.h"
 
 unsigned int ath11k_debug_mask;
 EXPORT_SYMBOL(ath11k_debug_mask);
@@ -66,6 +67,7 @@ static const struct ath11k_hw_params ath11k_hw_params[] = {
 		.supports_shadow_regs = false,
 		.idle_ps = false,
 		.cold_boot_calib = true,
+		.supports_suspend = false,
 	},
 	{
 		.hw_rev = ATH11K_HW_IPQ6018_HW10,
@@ -103,6 +105,7 @@ static const struct ath11k_hw_params ath11k_hw_params[] = {
 		.supports_shadow_regs = false,
 		.idle_ps = false,
 		.cold_boot_calib = true,
+		.supports_suspend = false,
 	},
 	{
 		.name = "qca6390 hw2.0",
@@ -139,9 +142,91 @@ static const struct ath11k_hw_params ath11k_hw_params[] = {
 		.supports_shadow_regs = true,
 		.idle_ps = true,
 		.cold_boot_calib = false,
+		.supports_suspend = true,
 	},
 };
 
+int ath11k_core_suspend(struct ath11k_base *ab)
+{
+	int ret;
+
+	if (!ab->hw_params.supports_suspend)
+		return -EOPNOTSUPP;
+
+	/* TODO: there can frames in queues so for now add delay as a hack.
+	 * Need to implement to handle and remove this delay.
+	 */
+	msleep(500);
+
+	ret = ath11k_dp_rx_pktlog_stop(ab, true);
+	if (ret) {
+		ath11k_warn(ab, "failed to stop dp rx (and timer) pktlog during suspend: %d\n",
+			    ret);
+		return ret;
+	}
+
+	ret = ath11k_wow_enable(ab);
+	if (ret) {
+		ath11k_warn(ab, "failed to enable wow during suspend: %d\n", ret);
+		return ret;
+	}
+
+	ret = ath11k_dp_rx_pktlog_stop(ab, false);
+	if (ret) {
+		ath11k_warn(ab, "failed to stop dp rx pktlog during suspend: %d\n",
+			    ret);
+		return ret;
+	}
+
+	ath11k_ce_stop_shadow_timers(ab);
+	ath11k_dp_stop_shadow_timers(ab);
+
+	ath11k_hif_irq_disable(ab);
+	ath11k_hif_ce_irq_disable(ab);
+
+	ret = ath11k_hif_suspend(ab);
+	if (!ret) {
+		ath11k_warn(ab, "failed to suspend hif: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(ath11k_core_suspend);
+
+int ath11k_core_resume(struct ath11k_base *ab)
+{
+	int ret;
+
+	if (!ab->hw_params.supports_suspend)
+		return -EOPNOTSUPP;
+
+	ret = ath11k_hif_resume(ab);
+	if (ret) {
+		ath11k_warn(ab, "failed to resume hif during resume: %d\n", ret);
+		return ret;
+	}
+
+	ath11k_hif_ce_irq_enable(ab);
+	ath11k_hif_irq_enable(ab);
+
+	ret = ath11k_dp_rx_pktlog_start(ab);
+	if (ret) {
+		ath11k_warn(ab, "failed to start rx pktlog during resume: %d\n",
+			    ret);
+		return ret;
+	}
+
+	ret = ath11k_wow_wakeup(ab);
+	if (ret) {
+		ath11k_warn(ab, "failed to wakeup wow during resume: %d\n", ret);
+		return ret;
+	}
+
+	return 0;
+}
+EXPORT_SYMBOL(ath11k_core_resume);
+
 int ath11k_core_check_dt(struct ath11k_base *ab)
 {
 	size_t max_len = sizeof(ab->qmi.target.bdf_ext);

drivers/net/wireless/ath/ath11k/core.h

@@ -897,6 +897,8 @@ void ath11k_core_free_bdf(struct ath11k_base *ab, struct ath11k_board_data *bd);
 int ath11k_core_check_dt(struct ath11k_base *ath11k);
 
 void ath11k_core_halt(struct ath11k *ar);
+int ath11k_core_resume(struct ath11k_base *ab);
+int ath11k_core_suspend(struct ath11k_base *ab);
 
 const struct firmware *ath11k_core_firmware_request(struct ath11k_base *ab,
 						    const char *filename);

drivers/net/wireless/ath/ath11k/dp.c

@@ -304,7 +304,7 @@ int ath11k_dp_srng_setup(struct ath11k_base *ab, struct dp_srng *ring,
 	return 0;
 }
 
-static void ath11k_dp_stop_shadow_timers(struct ath11k_base *ab)
+void ath11k_dp_stop_shadow_timers(struct ath11k_base *ab)
 {
 	int i;
 

drivers/net/wireless/ath/ath11k/dp.h

@@ -1641,5 +1641,6 @@ void ath11k_dp_shadow_stop_timer(struct ath11k_base *ab,
 void ath11k_dp_shadow_init_timer(struct ath11k_base *ab,
 				 struct ath11k_hp_update_timer *update_timer,
 				 u32 interval, u32 ring_id);
+void ath11k_dp_stop_shadow_timers(struct ath11k_base *ab);
 
 #endif

drivers/net/wireless/ath/ath11k/hw.h

@@ -156,6 +156,7 @@ struct ath11k_hw_params {
 	bool supports_shadow_regs;
 	bool idle_ps;
 	bool cold_boot_calib;
+	bool supports_suspend;
 };
 
 struct ath11k_hw_ops {

drivers/net/wireless/ath/ath11k/pci.c

@@ -1204,12 +1204,43 @@ static void ath11k_pci_shutdown(struct pci_dev *pdev)
 	ath11k_pci_power_down(ab);
 }
 
+static __maybe_unused int ath11k_pci_pm_suspend(struct device *dev)
+{
+	struct ath11k_base *ab = dev_get_drvdata(dev);
+	int ret;
+
+	ret = ath11k_core_suspend(ab);
+	if (ret)
+		ath11k_warn(ab, "failed to suspend core: %d\n", ret);
+
+	return ret;
+}
+
+static __maybe_unused int ath11k_pci_pm_resume(struct device *dev)
+{
+	struct ath11k_base *ab = dev_get_drvdata(dev);
+	int ret;
+
+	ret = ath11k_core_resume(ab);
+	if (ret)
+		ath11k_warn(ab, "failed to resume core: %d\n", ret);
+
+	return ret;
+}
+
+static SIMPLE_DEV_PM_OPS(ath11k_pci_pm_ops,
+			 ath11k_pci_pm_suspend,
+			 ath11k_pci_pm_resume);
+
 static struct pci_driver ath11k_pci_driver = {
 	.name = "ath11k_pci",
 	.id_table = ath11k_pci_id_table,
 	.probe = ath11k_pci_probe,
 	.remove = ath11k_pci_remove,
 	.shutdown = ath11k_pci_shutdown,
+#ifdef CONFIG_PM
+	.driver.pm = &ath11k_pci_pm_ops,
+#endif
 };
 
 static int ath11k_pci_init(void)