brcm80211: moved power conversion functions

Moved brcmu_mw_to_qdbm and brcmu_qdbm_to_mw functions into the only
file using them. Names were adjusted accordingly.

Reported-by: Johannes Berg <johannes@sipsolutions.net>
Reviewed-by: Roland Vossen <rvossen@broadcom.com>
Reviewed-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 86 insertions, 2 deletions

diff --git a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
index 27a748e5503..db9176d2d86 100644
--- a/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
+++ b/drivers/net/wireless/brcm80211/brcmfmac/wl_cfg80211.c
@@ -247,6 +247,90 @@ static const u32 __wl_cipher_suites[] = {
         WLAN_CIPHER_SUITE_AES_CMAC,
 };
 
+/* Quarter dBm units to mW
+ * Table starts at QDBM_OFFSET, so the first entry is mW for qdBm=153
+ * Table is offset so the last entry is largest mW value that fits in
+ * a u16.
+ */
+
+#define QDBM_OFFSET 153         /* Offset for first entry */
+#define QDBM_TABLE_LEN 40       /* Table size */
+
+/* Smallest mW value that will round up to the first table entry, QDBM_OFFSET.
+ * Value is ( mW(QDBM_OFFSET - 1) + mW(QDBM_OFFSET) ) / 2
+ */
+#define QDBM_TABLE_LOW_BOUND 6493       /* Low bound */
+
+/* Largest mW value that will round down to the last table entry,
+ * QDBM_OFFSET + QDBM_TABLE_LEN-1.
+ * Value is ( mW(QDBM_OFFSET + QDBM_TABLE_LEN - 1) +
+ * mW(QDBM_OFFSET + QDBM_TABLE_LEN) ) / 2.
+ */
+#define QDBM_TABLE_HIGH_BOUND 64938     /* High bound */
+
+static const u16 nqdBm_to_mW_map[QDBM_TABLE_LEN] = {
+/* qdBm:        +0      +1      +2      +3      +4      +5      +6      +7 */
+/* 153: */ 6683, 7079, 7499, 7943, 8414, 8913, 9441, 10000,
+/* 161: */ 10593, 11220, 11885, 12589, 13335, 14125, 14962, 15849,
+/* 169: */ 16788, 17783, 18836, 19953, 21135, 22387, 23714, 25119,
+/* 177: */ 26607, 28184, 29854, 31623, 33497, 35481, 37584, 39811,
+/* 185: */ 42170, 44668, 47315, 50119, 53088, 56234, 59566, 63096
+};
+
+static u16 brcmf_qdbm_to_mw(u8 qdbm)
+{
+        uint factor = 1;
+        int idx = qdbm - QDBM_OFFSET;
+
+        if (idx >= QDBM_TABLE_LEN)
+                /* clamp to max u16 mW value */
+                return 0xFFFF;
+
+        /* scale the qdBm index up to the range of the table 0-40
+         * where an offset of 40 qdBm equals a factor of 10 mW.
+         */
+        while (idx < 0) {
+                idx += 40;
+                factor *= 10;
+        }
+
+        /* return the mW value scaled down to the correct factor of 10,
+         * adding in factor/2 to get proper rounding.
+         */
+        return (nqdBm_to_mW_map[idx] + factor / 2) / factor;
+}
+
+static u8 brcmf_mw_to_qdbm(u16 mw)
+{
+        u8 qdbm;
+        int offset;
+        uint mw_uint = mw;
+        uint boundary;
+
+        /* handle boundary case */
+        if (mw_uint <= 1)
+                return 0;
+
+        offset = QDBM_OFFSET;
+
+        /* move mw into the range of the table */
+        while (mw_uint < QDBM_TABLE_LOW_BOUND) {
+                mw_uint *= 10;
+                offset -= 40;
+        }
+
+        for (qdbm = 0; qdbm < QDBM_TABLE_LEN - 1; qdbm++) {
+                boundary = nqdBm_to_mW_map[qdbm] + (nqdBm_to_mW_map[qdbm + 1] -
+                                                    nqdBm_to_mW_map[qdbm]) / 2;
+                if (mw_uint < boundary)
+                        break;
+        }
+
+        qdbm += (u8) offset;
+
+        return qdbm;
+}
+
 /* function for reading/writing a single u32 from/to the dongle */
 static int
 brcmf_exec_dcmd_u32(struct net_device *ndev, u32 cmd, u32 *par)
@@ -1380,7 +1464,7 @@ brcmf_cfg80211_set_tx_power(struct wiphy *wiphy,
         else
                 txpwrmw = (u16) dbm;
         err = brcmf_dev_intvar_set(ndev, "qtxpower",
-                        (s32) (brcmu_mw_to_qdbm(txpwrmw)));
+                        (s32) (brcmf_mw_to_qdbm(txpwrmw)));
         if (err)
                 WL_ERR("qtxpower error (%d)\n", err);
         cfg_priv->conf->tx_power = dbm;
@@ -1409,7 +1493,7 @@ static s32 brcmf_cfg80211_get_tx_power(struct wiphy *wiphy, s32 *dbm)
         }
 
         result = (u8) (txpwrdbm & ~WL_TXPWR_OVERRIDE);
-        *dbm = (s32) brcmu_qdbm_to_mw(result);
+        *dbm = (s32) brcmf_qdbm_to_mw(result);
 
 done:
         WL_TRACE("Exit\n");