ath11k: add support for spectral scan

spectral scan control interface is exposed through debugfs eentry.
Relayfs is used to collect the spectral data. These interfaces are
similar to ath10k spectral.

spectral debugfs interfaces are below,

echo background > /sys/kernel/debug/ieee80211/phy0/ath11k/spectral_scan_ctl
echo trigger > /sys/kernel/debug/ieee80211/phy0/ath11k/spectral_scan_ctl
iw dev wlan0 scan
echo disable > /sys/kernel/debug/ieee80211/phy0/ath11k/spectral_scan_ctl
cat /sys/kernel/debug/ieee80211/phy0/ath11k/spectral_scan0 > fft_samples.dump

Tested-on: IPQ8074 WLAN.HK.2.1.0.1-01228-QCAHKSWPL_SILICONZ-1

Signed-off-by: Karthikeyan Periyasamy <periyasa@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/1591688014-26441-2-git-send-email-periyasa@codeaurora.org

drivers/net/wireless/ath/ath11k/Kconfig

@@ -34,3 +34,12 @@ config ATH11K_TRACING
 	depends on ATH11K && EVENT_TRACING
 	---help---
 	  Select this to use ath11k tracing infrastructure.
+
+config ATH11K_SPECTRAL
+	bool "QCA ath11k spectral scan support"
+	depends on ATH11K_DEBUGFS
+	depends on RELAY
+	help
+	  Enable ath11k spectral scan support
+
+	  Say Y to enable access to the FFT/spectral data via debugfs.

drivers/net/wireless/ath/ath11k/Makefile

@@ -22,6 +22,7 @@ ath11k-$(CONFIG_ATH11K_DEBUGFS) += debug_htt_stats.o debugfs_sta.o
 ath11k-$(CONFIG_NL80211_TESTMODE) += testmode.o
 ath11k-$(CONFIG_ATH11K_TRACING) += trace.o
 ath11k-$(CONFIG_THERMAL) += thermal.o
+ath11k-$(CONFIG_ATH11K_SPECTRAL) += spectral.o
 
 # for tracing framework to find trace.h
 CFLAGS_trace.o := -I$(src)

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

@@ -400,8 +400,16 @@ static int ath11k_core_pdev_create(struct ath11k_base *ab)
 		goto err_dp_pdev_free;
 	}
 
+	ret = ath11k_spectral_init(ab);
+	if (ret) {
+		ath11k_err(ab, "failed to init spectral %d\n", ret);
+		goto err_thermal_unregister;
+	}
+
 	return 0;
 
+err_thermal_unregister:
+	ath11k_thermal_unregister(ab);
 err_dp_pdev_free:
 	ath11k_dp_pdev_free(ab);
 err_mac_unregister:
@@ -414,6 +422,7 @@ static int ath11k_core_pdev_create(struct ath11k_base *ab)
 
 static void ath11k_core_pdev_destroy(struct ath11k_base *ab)
 {
+	ath11k_spectral_deinit(ab);
 	ath11k_thermal_unregister(ab);
 	ath11k_mac_unregister(ab);
 	ath11k_hif_irq_disable(ab);
@@ -582,6 +591,7 @@ static int ath11k_core_reconfigure_on_crash(struct ath11k_base *ab)
 	ath11k_thermal_unregister(ab);
 	ath11k_hif_irq_disable(ab);
 	ath11k_dp_pdev_free(ab);
+	ath11k_spectral_deinit(ab);
 	ath11k_hif_stop(ab);
 	ath11k_wmi_detach(ab);
 	ath11k_dp_pdev_reo_cleanup(ab);

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

@@ -22,6 +22,7 @@
 #include "reg.h"
 #include "thermal.h"
 #include "dbring.h"
+#include "spectral.h"
 
 #define SM(_v, _f) (((_v) << _f##_LSB) & _f##_MASK)
 
@@ -216,6 +217,7 @@ struct ath11k_vif {
 
 	bool is_started;
 	bool is_up;
+	bool spectral_enabled;
 	u32 aid;
 	u8 bssid[ETH_ALEN];
 	struct cfg80211_bitrate_mask bitrate_mask;
@@ -541,6 +543,9 @@ struct ath11k {
 	u32 cached_ppdu_id;
 #ifdef CONFIG_ATH11K_DEBUGFS
 	struct ath11k_debug debug;
+#endif
+#ifdef CONFIG_ATH11K_SPECTRAL
+	struct ath11k_spectral spectral;
 #endif
 	bool dfs_block_radar_events;
 	struct ath11k_thermal thermal;

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

@@ -267,6 +267,9 @@ int ath11k_dbring_buffer_release_event(struct ath11k_base *ab,
 	}
 
 	switch (ev->fixed.module_id) {
+	case WMI_DIRECT_BUF_SPECTRAL:
+		ring = ath11k_spectral_get_dbring(ar);
+		break;
 	default:
 		ring = NULL;
 		ath11k_warn(ab, "Recv dma buffer release ev on unsupp module %d\n",

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

@@ -2208,6 +2208,9 @@ static int ath11k_start_scan(struct ath11k *ar,
 
 	lockdep_assert_held(&ar->conf_mutex);
 
+	if (ath11k_spectral_get_mode(ar) == ATH11K_SPECTRAL_BACKGROUND)
+		ath11k_spectral_reset_buffer(ar);
+
 	ret = ath11k_wmi_send_scan_start_cmd(ar, arg);
 	if (ret)
 		return ret;