bcma: extract antenna gains from SPROM correctly

Just like in case of SSB SPROMs they are encoded in a bit tricky way.
SPROM struct already uses s8 type and it's supposed to store decoded
values.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>

1 files changed, 33 insertions, 8 deletions

diff --git a/drivers/bcma/sprom.c b/drivers/bcma/sprom.c
index 72bf4540f565..a9dfb1ac138d 100644
--- a/drivers/bcma/sprom.c
+++ b/drivers/bcma/sprom.c
@@ -201,6 +201,23 @@ static int bcma_sprom_valid(struct bcma_bus *bus, const u16 *sprom,
                 SPEX(_field[7], _offset + 14, _mask, _shift);   \
         } while (0)
 
+static s8 sprom_extract_antgain(const u16 *in, u16 offset, u16 mask, u16 shift)
+{
+        u16 v;
+        u8 gain;
+
+        v = in[SPOFF(offset)];
+        gain = (v & mask) >> shift;
+        if (gain == 0xFF) {
+                gain = 8; /* If unset use 2dBm */
+        } else {
+                /* Q5.2 Fractional part is stored in 0xC0 */
+                gain = ((gain & 0xC0) >> 6) | ((gain & 0x3F) << 2);
+        }
+
+        return (s8)gain;
+}
+
 static void bcma_sprom_extract_r8(struct bcma_bus *bus, const u16 *sprom)
 {
         u16 v, o;
@@ -381,14 +398,22 @@ static void bcma_sprom_extract_r8(struct bcma_bus *bus, const u16 *sprom)
         SPEX32(ofdm5ghpo, SSB_SPROM8_OFDM5GHPO, ~0, 0);
 
         /* Extract the antenna gain values. */
-        SPEX(antenna_gain.a0, SSB_SPROM8_AGAIN01,
-             SSB_SPROM8_AGAIN0, SSB_SPROM8_AGAIN0_SHIFT);
-        SPEX(antenna_gain.a1, SSB_SPROM8_AGAIN01,
-             SSB_SPROM8_AGAIN1, SSB_SPROM8_AGAIN1_SHIFT);
-        SPEX(antenna_gain.a2, SSB_SPROM8_AGAIN23,
-             SSB_SPROM8_AGAIN2, SSB_SPROM8_AGAIN2_SHIFT);
-        SPEX(antenna_gain.a3, SSB_SPROM8_AGAIN23,
-             SSB_SPROM8_AGAIN3, SSB_SPROM8_AGAIN3_SHIFT);
+        bus->sprom.antenna_gain.a0 = sprom_extract_antgain(sprom,
+                                                           SSB_SPROM8_AGAIN01,
+                                                           SSB_SPROM8_AGAIN0,
+                                                           SSB_SPROM8_AGAIN0_SHIFT);
+        bus->sprom.antenna_gain.a1 = sprom_extract_antgain(sprom,
+                                                           SSB_SPROM8_AGAIN01,
+                                                           SSB_SPROM8_AGAIN1,
+                                                           SSB_SPROM8_AGAIN1_SHIFT);
+        bus->sprom.antenna_gain.a2 = sprom_extract_antgain(sprom,
+                                                           SSB_SPROM8_AGAIN23,
+                                                           SSB_SPROM8_AGAIN2,
+                                                           SSB_SPROM8_AGAIN2_SHIFT);
+        bus->sprom.antenna_gain.a3 = sprom_extract_antgain(sprom,
+                                                           SSB_SPROM8_AGAIN23,
+                                                           SSB_SPROM8_AGAIN3,
+                                                           SSB_SPROM8_AGAIN3_SHIFT);
 
         SPEX(leddc_on_time, SSB_SPROM8_LEDDC, SSB_SPROM8_LEDDC_ON,
              SSB_SPROM8_LEDDC_ON_SHIFT);