p54: more accurate rssi to dBm conversion

This patch replaces the static rssi auto calibration data
with more precise values out of the device's eeprom.

Signed-off-by: Christian Lamparter <chunkeey@web.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

3 files changed, 68 insertions, 26 deletions

diff --git a/drivers/net/wireless/p54/p54.h b/drivers/net/wireless/p54/p54.h
index 23b80ef4d015..e0a68815a471 100644
--- a/drivers/net/wireless/p54/p54.h
+++ b/drivers/net/wireless/p54/p54.h
@@ -61,6 +61,13 @@ struct p54_edcf_queue_param {
         __le16 txop;
 } __attribute__ ((packed));
 
+struct p54_rssi_linear_approximation {
+        s16 mul;
+        s16 add;
+        s16 longbow_unkn;
+        s16 longbow_unk2;
+};
+
 #define EEPROM_READBACK_LEN 0x3fc
 
 #define ISL38XX_DEV_FIRMWARE_ADDR 0x20000
@@ -91,6 +98,7 @@ struct p54_common {
         struct pda_channel_output_limit *output_limit;
         unsigned int output_limit_len;
         struct pda_pa_curve_data *curve_data;
+        struct p54_rssi_linear_approximation rssical_db[IEEE80211_NUM_BANDS];
         unsigned int filter_flags;
         bool use_short_slot;
         u16 rxhw;
diff --git a/drivers/net/wireless/p54/p54common.c b/drivers/net/wireless/p54/p54common.c
index ddb858608a50..05eb677aa3e1 100644
--- a/drivers/net/wireless/p54/p54common.c
+++ b/drivers/net/wireless/p54/p54common.c
@@ -335,6 +335,36 @@ static const char *p54_rf_chips[] = { "NULL", "Duette3", "Duette2",
                               "Frisbee", "Xbow", "Longbow", "NULL", "NULL" };
 static int p54_init_xbow_synth(struct ieee80211_hw *dev);
 
+static void p54_parse_rssical(struct ieee80211_hw *dev, void *data, int len,
+                             u16 type)
+{
+        struct p54_common *priv = dev->priv;
+        int offset = (type == PDR_RSSI_LINEAR_APPROXIMATION_EXTENDED) ? 2 : 0;
+        int entry_size = sizeof(struct pda_rssi_cal_entry) + offset;
+        int num_entries = (type == PDR_RSSI_LINEAR_APPROXIMATION) ? 1 : 2;
+        int i;
+
+        if (len != (entry_size * num_entries)) {
+                printk(KERN_ERR "%s: unknown rssi calibration data packing "
+                                 " type:(%x) len:%d.\n",
+                       wiphy_name(dev->wiphy), type, len);
+
+                print_hex_dump_bytes("rssical:", DUMP_PREFIX_NONE,
+                                     data, len);
+
+                printk(KERN_ERR "%s: please report this issue.\n",
+                        wiphy_name(dev->wiphy));
+                return;
+        }
+
+        for (i = 0; i < num_entries; i++) {
+                struct pda_rssi_cal_entry *cal = data +
+                                                 (offset + i * entry_size);
+                priv->rssical_db[i].mul = (s16) le16_to_cpu(cal->mul);
+                priv->rssical_db[i].add = (s16) le16_to_cpu(cal->add);
+        }
+}
+
 static int p54_parse_eeprom(struct ieee80211_hw *dev, void *eeprom, int len)
 {
         struct p54_common *priv = dev->priv;
@@ -434,6 +464,12 @@ static int p54_parse_eeprom(struct ieee80211_hw *dev, void *eeprom, int len)
                 case PDR_HARDWARE_PLATFORM_COMPONENT_ID:
                         priv->version = *(u8 *)(entry->data + 1);
                         break;
+                case PDR_RSSI_LINEAR_APPROXIMATION:
+                case PDR_RSSI_LINEAR_APPROXIMATION_DUAL_BAND:
+                case PDR_RSSI_LINEAR_APPROXIMATION_EXTENDED:
+                        p54_parse_rssical(dev, entry->data, data_len,
+                                          le16_to_cpu(entry->code));
+                        break;
                 case PDR_END:
                         /* make it overrun */
                         entry_len = len;
@@ -453,10 +489,7 @@ static int p54_parse_eeprom(struct ieee80211_hw *dev, void *eeprom, int len)
                 case PDR_DEFAULT_COUNTRY:
                 case PDR_ANTENNA_GAIN:
                 case PDR_PRISM_INDIGO_PA_CALIBRATION_DATA:
-                case PDR_RSSI_LINEAR_APPROXIMATION:
-                case PDR_RSSI_LINEAR_APPROXIMATION_DUAL_BAND:
                 case PDR_REGULATORY_POWER_LIMITS:
-                case PDR_RSSI_LINEAR_APPROXIMATION_EXTENDED:
                 case PDR_RADIATED_TRANSMISSION_CORRECTION:
                 case PDR_PRISM_TX_IQ_CALIBRATION:
                 case PDR_BASEBAND_REGISTERS:
@@ -527,8 +560,11 @@ static int p54_parse_eeprom(struct ieee80211_hw *dev, void *eeprom, int len)
 
 static int p54_rssi_to_dbm(struct ieee80211_hw *dev, int rssi)
 {
-        /* TODO: get the rssi_add & rssi_mul data from the eeprom */
-        return ((rssi * 0x83) / 64 - 400) / 4;
+        struct p54_common *priv = dev->priv;
+        int band = dev->conf.channel->band;
+
+        return ((rssi * priv->rssical_db[band].mul) / 64 +
+                         priv->rssical_db[band].add) / 4;
 }
 
 static int p54_rx_data(struct ieee80211_hw *dev, struct sk_buff *skb)
@@ -1466,15 +1502,15 @@ static int p54_setup_mac(struct ieee80211_hw *dev)
         return 0;
 }
 
-static int p54_scan(struct ieee80211_hw *dev, u16 mode, u16 dwell,
-                    u16 frequency)
+static int p54_scan(struct ieee80211_hw *dev, u16 mode, u16 dwell)
 {
         struct p54_common *priv = dev->priv;
         struct sk_buff *skb;
         struct p54_scan *chan;
         unsigned int i;
         void *entry;
-        __le16 freq = cpu_to_le16(frequency);
+        __le16 freq = cpu_to_le16(dev->conf.channel->center_freq);
+        int band = dev->conf.channel->band;
 
         skb = p54_alloc_skb(dev, P54_HDR_FLAG_CONTROL_OPSET, sizeof(*chan) +
                             sizeof(struct p54_hdr), P54_CONTROL_TYPE_SCAN,
@@ -1535,11 +1571,11 @@ static int p54_scan(struct ieee80211_hw *dev, u16 mode, u16 dwell,
         }
 
         if (priv->fw_var < 0x500) {
-                chan->v1.rssical_mul = cpu_to_le16(130);
-                chan->v1.rssical_add = cpu_to_le16(0xfe70);
+                chan->v1_rssi.mul = cpu_to_le16(priv->rssical_db[band].mul);
+                chan->v1_rssi.add = cpu_to_le16(priv->rssical_db[band].add);
         } else {
-                chan->v2.rssical_mul = cpu_to_le16(130);
-                chan->v2.rssical_add = cpu_to_le16(0xfe70);
+                chan->v2.rssi.mul = cpu_to_le16(priv->rssical_db[band].mul);
+                chan->v2.rssi.add = cpu_to_le16(priv->rssical_db[band].add);
                 chan->v2.basic_rate_mask = cpu_to_le32(priv->basic_rate_mask);
                 memset(chan->v2.rts_rates, 0, 8);
         }
@@ -1801,8 +1837,7 @@ static int p54_config(struct ieee80211_hw *dev, u32 changed)
                         goto out;
         }
         if (changed & IEEE80211_CONF_CHANGE_CHANNEL) {
-                ret = p54_scan(dev, P54_SCAN_EXIT, 0,
-                               conf->channel->center_freq);
+                ret = p54_scan(dev, P54_SCAN_EXIT, 0);
                 if (ret)
                         goto out;
         }
@@ -1828,8 +1863,7 @@ static int p54_config_interface(struct ieee80211_hw *dev,
         }
 
         if (conf->changed & IEEE80211_IFCC_BEACON) {
-                ret = p54_scan(dev, P54_SCAN_EXIT, 0,
-                               dev->conf.channel->center_freq);
+                ret = p54_scan(dev, P54_SCAN_EXIT, 0);
                 if (ret)
                         goto out;
                 ret = p54_setup_mac(dev);
@@ -1968,8 +2002,7 @@ static void p54_bss_info_changed(struct ieee80211_hw *dev,
                         priv->basic_rate_mask = info->basic_rates;
                 p54_setup_mac(dev);
                 if (priv->fw_var >= 0x500)
-                        p54_scan(dev, P54_SCAN_EXIT, 0,
-                                 dev->conf.channel->center_freq);
+                        p54_scan(dev, P54_SCAN_EXIT, 0);
         }
         if (changed & BSS_CHANGED_ASSOC) {
                 if (info->assoc) {
diff --git a/drivers/net/wireless/p54/p54common.h b/drivers/net/wireless/p54/p54common.h
index 06e1643cc295..6c824e40f3ba 100644
--- a/drivers/net/wireless/p54/p54common.h
+++ b/drivers/net/wireless/p54/p54common.h
@@ -178,6 +178,11 @@ struct pda_pa_curve_data {
         u8 data[0];
 } __attribute__ ((packed));
 
+struct pda_rssi_cal_entry {
+        __le16 mul;
+        __le16 add;
+} __attribute__ ((packed));
+
 /*
  * this defines the PDR codes used to build PDAs as defined in document
  * number 553155. The current implementation mirrors version 1.1 of the
@@ -429,22 +434,18 @@ struct p54_scan {
         u8 dup_16qam;
         u8 dup_64qam;
         union {
-                struct {
-                        __le16 rssical_mul;
-                        __le16 rssical_add;
-                } v1 __attribute__ ((packed));
+                struct pda_rssi_cal_entry v1_rssi;
 
                 struct {
                         __le32 basic_rate_mask;
                         u8 rts_rates[8];
-                        __le16 rssical_mul;
-                        __le16 rssical_add;
+                        struct pda_rssi_cal_entry rssi;
                 } v2 __attribute__ ((packed));
         } __attribute__ ((packed));
 } __attribute__ ((packed));
 
-#define P54_SCAN_V1_LEN (sizeof(struct p54_scan)-12)
-#define P54_SCAN_V2_LEN (sizeof(struct p54_scan))
+#define P54_SCAN_V1_LEN 0x70
+#define P54_SCAN_V2_LEN 0x7c
 
 struct p54_led {
         __le16 mode;