ath6kl: Add debugfs entry to modify roaming parameters.

Firmware initiates roaming only after it reaches a rssi of 20.
This lower rssi threshold can be modified through a wmi command
to modify the roaming behavior.

kvalo: rename debugfs functions and move comment about rssi units next to
ath6kl_wmi_set_roam_lrssi_cmd()

Signed-off-by: Vivek Natarajan <nataraja@qca.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>

5 files changed, 119 insertions, 0 deletions

diff --git a/drivers/net/wireless/ath/ath6kl/core.h b/drivers/net/wireless/ath/ath6kl/core.h
index de5308727b62..faf801571214 100644
--- a/drivers/net/wireless/ath/ath6kl/core.h
+++ b/drivers/net/wireless/ath/ath6kl/core.h
@@ -394,6 +394,7 @@ struct ath6kl {
         u16 bss_ch;
         u16 listen_intvl_b;
         u16 listen_intvl_t;
+        u8 lrssi_roam_threshold;
         struct ath6kl_version version;
         u32 target_type;
         u8 tx_pwr;
diff --git a/drivers/net/wireless/ath/ath6kl/debug.c b/drivers/net/wireless/ath/ath6kl/debug.c
index cb89776f9485..8bc475376372 100644
--- a/drivers/net/wireless/ath/ath6kl/debug.c
+++ b/drivers/net/wireless/ath/ath6kl/debug.c
@@ -714,6 +714,51 @@ static const struct file_operations fops_reg_dump = {
         .llseek = default_llseek,
 };
 
+static ssize_t ath6kl_lrssi_roam_write(struct file *file,
+                                       const char __user *user_buf,
+                                       size_t count, loff_t *ppos)
+{
+        struct ath6kl *ar = file->private_data;
+        unsigned long lrssi_roam_threshold;
+        char buf[32];
+        ssize_t len;
+
+        len = min(count, sizeof(buf) - 1);
+        if (copy_from_user(buf, user_buf, len))
+                return -EFAULT;
+
+        buf[len] = '\0';
+        if (strict_strtoul(buf, 0, &lrssi_roam_threshold))
+                return -EINVAL;
+
+        ar->lrssi_roam_threshold = lrssi_roam_threshold;
+
+        ath6kl_wmi_set_roam_lrssi_cmd(ar->wmi, ar->lrssi_roam_threshold);
+
+        return count;
+}
+
+static ssize_t ath6kl_lrssi_roam_read(struct file *file,
+                                      char __user *user_buf,
+                                      size_t count, loff_t *ppos)
+{
+        struct ath6kl *ar = file->private_data;
+        char buf[32];
+        unsigned int len;
+
+        len = snprintf(buf, sizeof(buf), "%u\n", ar->lrssi_roam_threshold);
+
+        return simple_read_from_buffer(user_buf, count, ppos, buf, len);
+}
+
+static const struct file_operations fops_lrssi_roam_threshold = {
+        .read = ath6kl_lrssi_roam_read,
+        .write = ath6kl_lrssi_roam_write,
+        .open = ath6kl_debugfs_open,
+        .owner = THIS_MODULE,
+        .llseek = default_llseek,
+};
+
 int ath6kl_debug_init(struct ath6kl *ar)
 {
         ar->debug.fwlog_buf.buf = vmalloc(ATH6KL_FWLOG_SIZE);
@@ -760,6 +805,8 @@ int ath6kl_debug_init(struct ath6kl *ar)
         debugfs_create_file("reg_dump", S_IRUSR, ar->debugfs_phy, ar,
                             &fops_reg_dump);
 
+        debugfs_create_file("lrssi_roam_threshold", S_IRUSR | S_IWUSR,
+                            ar->debugfs_phy, ar, &fops_lrssi_roam_threshold);
         return 0;
 }
 
diff --git a/drivers/net/wireless/ath/ath6kl/init.c b/drivers/net/wireless/ath/ath6kl/init.c
index d234dc22e709..3d67025b72c4 100644
--- a/drivers/net/wireless/ath/ath6kl/init.c
+++ b/drivers/net/wireless/ath/ath6kl/init.c
@@ -280,6 +280,7 @@ static void ath6kl_init_control_info(struct ath6kl *ar)
         memset(&ar->sc_params, 0, sizeof(ar->sc_params));
         ar->sc_params.short_scan_ratio = WMI_SHORTSCANRATIO_DEFAULT;
         ar->sc_params.scan_ctrl_flags = DEFAULT_SCAN_CTRL_FLAGS;
+        ar->lrssi_roam_threshold = DEF_LRSSI_ROAM_THRESHOLD;
 
         memset((u8 *)ar->sta_list, 0,
                AP_MAX_NUM_STA * sizeof(struct ath6kl_sta));
diff --git a/drivers/net/wireless/ath/ath6kl/wmi.c b/drivers/net/wireless/ath/ath6kl/wmi.c
index 7201a72ac1b8..c9ec6303db72 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.c
+++ b/drivers/net/wireless/ath/ath6kl/wmi.c
@@ -666,6 +666,35 @@ static int ath6kl_wmi_ready_event_rx(struct wmi *wmi, u8 *datap, int len)
         return 0;
 }
 
+/*
+ * Mechanism to modify the roaming behavior in the firmware. The lower rssi
+ * at which the station has to roam can be passed with
+ * WMI_SET_LRSSI_SCAN_PARAMS. Subtract 96 from RSSI to get the signal level
+ * in dBm.
+ */
+int ath6kl_wmi_set_roam_lrssi_cmd(struct wmi *wmi, u8 lrssi)
+{
+        struct sk_buff *skb;
+        struct roam_ctrl_cmd *cmd;
+
+        skb = ath6kl_wmi_get_new_buf(sizeof(*cmd));
+        if (!skb)
+                return -ENOMEM;
+
+        cmd = (struct roam_ctrl_cmd *) skb->data;
+
+        cmd->info.params.lrssi_scan_period = cpu_to_le16(DEF_LRSSI_SCAN_PERIOD);
+        cmd->info.params.lrssi_scan_threshold = a_cpu_to_sle16(lrssi +
+                                                       DEF_SCAN_FOR_ROAM_INTVL);
+        cmd->info.params.lrssi_roam_threshold = a_cpu_to_sle16(lrssi);
+        cmd->info.params.roam_rssi_floor = DEF_LRSSI_ROAM_FLOOR;
+        cmd->roam_ctrl = WMI_SET_LRSSI_SCAN_PARAMS;
+
+        ath6kl_wmi_cmd_send(wmi, skb, WMI_SET_ROAM_CTRL_CMDID, NO_SYNC_WMIFLAG);
+
+        return 0;
+}
+
 static int ath6kl_wmi_connect_event_rx(struct wmi *wmi, u8 *datap, int len)
 {
         struct wmi_connect_event *ev;
diff --git a/drivers/net/wireless/ath/ath6kl/wmi.h b/drivers/net/wireless/ath/ath6kl/wmi.h
index 1c565816f622..a78e21b91776 100644
--- a/drivers/net/wireless/ath/ath6kl/wmi.h
+++ b/drivers/net/wireless/ath/ath6kl/wmi.h
@@ -1333,6 +1333,46 @@ enum wmi_bi_ftype {
         PROBEREQ_FTYPE,
 };
 
+#define DEF_LRSSI_SCAN_PERIOD            5
+#define DEF_LRSSI_ROAM_THRESHOLD        20
+#define DEF_LRSSI_ROAM_FLOOR            60
+#define DEF_SCAN_FOR_ROAM_INTVL          2
+
+enum wmi_roam_ctrl {
+        WMI_FORCE_ROAM = 1,
+        WMI_SET_ROAM_MODE,
+        WMI_SET_HOST_BIAS,
+        WMI_SET_LRSSI_SCAN_PARAMS,
+};
+
+struct bss_bias {
+        u8 bssid[ETH_ALEN];
+        u8  bias;
+} __packed;
+
+struct bss_bias_info {
+        u8 num_bss;
+        struct bss_bias bss_bias[1];
+} __packed;
+
+struct low_rssi_scan_params {
+        __le16 lrssi_scan_period;
+        a_sle16 lrssi_scan_threshold;
+        a_sle16 lrssi_roam_threshold;
+        u8 roam_rssi_floor;
+        u8 reserved[1];
+} __packed;
+
+struct roam_ctrl_cmd {
+        union {
+                u8 bssid[ETH_ALEN];
+                u8 roam_mode;
+                struct bss_bias_info bss;
+                struct low_rssi_scan_params params;
+        } __packed info;
+        u8 roam_ctrl;
+} __packed;
+
 struct wmi_bss_info_hdr {
         __le16 ch;
 
@@ -2190,6 +2230,7 @@ int ath6kl_wmi_test_cmd(struct wmi *wmi, void *buf, size_t len);
 s32 ath6kl_wmi_get_rate(s8 rate_index);
 
 int ath6kl_wmi_set_ip_cmd(struct wmi *wmi, struct wmi_set_ip_cmd *ip_cmd);
+int ath6kl_wmi_set_roam_lrssi_cmd(struct wmi *wmi, u8 lrssi);
 
 struct bss *ath6kl_wmi_find_ssid_node(struct wmi *wmi, u8 *ssid,
                                       u32 ssid_len, bool is_wpa2,