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path: root/drivers/net/wireless/rt2x00/rt2800lib.c
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Diffstat (limited to 'drivers/net/wireless/rt2x00/rt2800lib.c')
-rw-r--r--drivers/net/wireless/rt2x00/rt2800lib.c100
1 files changed, 77 insertions, 23 deletions
diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c
index 59474ae0aec0..c0441a715c96 100644
--- a/drivers/net/wireless/rt2x00/rt2800lib.c
+++ b/drivers/net/wireless/rt2x00/rt2800lib.c
@@ -2520,20 +2520,37 @@ static int rt2800_get_txpower_bw_comp(struct rt2x00_dev *rt2x00dev,
return comp_value;
}
+static int rt2800_get_txpower_reg_delta(struct rt2x00_dev *rt2x00dev,
+ int power_level, int max_power)
+{
+ int delta;
+
+ if (test_bit(CAPABILITY_POWER_LIMIT, &rt2x00dev->cap_flags))
+ return 0;
+
+ /*
+ * XXX: We don't know the maximum transmit power of our hardware since
+ * the EEPROM doesn't expose it. We only know that we are calibrated
+ * to 100% tx power.
+ *
+ * Hence, we assume the regulatory limit that cfg80211 calulated for
+ * the current channel is our maximum and if we are requested to lower
+ * the value we just reduce our tx power accordingly.
+ */
+ delta = power_level - max_power;
+ return min(delta, 0);
+}
+
static u8 rt2800_compensate_txpower(struct rt2x00_dev *rt2x00dev, int is_rate_b,
enum ieee80211_band band, int power_level,
u8 txpower, int delta)
{
- u32 reg;
u16 eeprom;
u8 criterion;
u8 eirp_txpower;
u8 eirp_txpower_criterion;
u8 reg_limit;
- if (!((band == IEEE80211_BAND_5GHZ) && is_rate_b))
- return txpower;
-
if (test_bit(CAPABILITY_POWER_LIMIT, &rt2x00dev->cap_flags)) {
/*
* Check if eirp txpower exceed txpower_limit.
@@ -2542,11 +2559,13 @@ static u8 rt2800_compensate_txpower(struct rt2x00_dev *rt2x00dev, int is_rate_b,
* .11b data rate need add additional 4dbm
* when calculating eirp txpower.
*/
- rt2800_register_read(rt2x00dev, TX_PWR_CFG_0, &reg);
- criterion = rt2x00_get_field32(reg, TX_PWR_CFG_0_6MBS);
+ rt2x00_eeprom_read(rt2x00dev, EEPROM_TXPOWER_BYRATE + 1,
+ &eeprom);
+ criterion = rt2x00_get_field16(eeprom,
+ EEPROM_TXPOWER_BYRATE_RATE0);
- rt2x00_eeprom_read(rt2x00dev,
- EEPROM_EIRP_MAX_TX_POWER, &eeprom);
+ rt2x00_eeprom_read(rt2x00dev, EEPROM_EIRP_MAX_TX_POWER,
+ &eeprom);
if (band == IEEE80211_BAND_2GHZ)
eirp_txpower_criterion = rt2x00_get_field16(eeprom,
@@ -2563,36 +2582,71 @@ static u8 rt2800_compensate_txpower(struct rt2x00_dev *rt2x00dev, int is_rate_b,
} else
reg_limit = 0;
- return txpower + delta - reg_limit;
+ txpower = max(0, txpower + delta - reg_limit);
+ return min_t(u8, txpower, 0xc);
}
+/*
+ * We configure transmit power using MAC TX_PWR_CFG_{0,...,N} registers and
+ * BBP R1 register. TX_PWR_CFG_X allow to configure per rate TX power values,
+ * 4 bits for each rate (tune from 0 to 15 dBm). BBP_R1 controls transmit power
+ * for all rates, but allow to set only 4 discrete values: -12, -6, 0 and 6 dBm.
+ * Reference per rate transmit power values are located in the EEPROM at
+ * EEPROM_TXPOWER_BYRATE offset. We adjust them and BBP R1 settings according to
+ * current conditions (i.e. band, bandwidth, temperature, user settings).
+ */
static void rt2800_config_txpower(struct rt2x00_dev *rt2x00dev,
- enum ieee80211_band band,
+ struct ieee80211_channel *chan,
int power_level)
{
- u8 txpower;
+ u8 txpower, r1;
u16 eeprom;
- int i, is_rate_b;
- u32 reg;
- u8 r1;
- u32 offset;
- int delta;
+ u32 reg, offset;
+ int i, is_rate_b, delta, power_ctrl;
+ enum ieee80211_band band = chan->band;
/*
- * Calculate HT40 compensation delta
+ * Calculate HT40 compensation. For 40MHz we need to add or subtract
+ * value read from EEPROM (different for 2GHz and for 5GHz).
*/
delta = rt2800_get_txpower_bw_comp(rt2x00dev, band);
/*
- * calculate temperature compensation delta
+ * Calculate temperature compensation. Depends on measurement of current
+ * TSSI (Transmitter Signal Strength Indication) we know TX power (due
+ * to temperature or maybe other factors) is smaller or bigger than
+ * expected. We adjust it, based on TSSI reference and boundaries values
+ * provided in EEPROM.
*/
delta += rt2800_get_gain_calibration_delta(rt2x00dev);
/*
- * set to normal bbp tx power control mode: +/- 0dBm
+ * Decrease power according to user settings, on devices with unknown
+ * maximum tx power. For other devices we take user power_level into
+ * consideration on rt2800_compensate_txpower().
+ */
+ delta += rt2800_get_txpower_reg_delta(rt2x00dev, power_level,
+ chan->max_power);
+
+ /*
+ * BBP_R1 controls TX power for all rates, it allow to set the following
+ * gains -12, -6, 0, +6 dBm by setting values 2, 1, 0, 3 respectively.
+ *
+ * TODO: we do not use +6 dBm option to do not increase power beyond
+ * regulatory limit, however this could be utilized for devices with
+ * CAPABILITY_POWER_LIMIT.
*/
rt2800_bbp_read(rt2x00dev, 1, &r1);
- rt2x00_set_field8(&r1, BBP1_TX_POWER_CTRL, 0);
+ if (delta <= -12) {
+ power_ctrl = 2;
+ delta += 12;
+ } else if (delta <= -6) {
+ power_ctrl = 1;
+ delta += 6;
+ } else {
+ power_ctrl = 0;
+ }
+ rt2x00_set_field8(&r1, BBP1_TX_POWER_CTRL, power_ctrl);
rt2800_bbp_write(rt2x00dev, 1, r1);
offset = TX_PWR_CFG_0;
@@ -2710,7 +2764,7 @@ static void rt2800_config_txpower(struct rt2x00_dev *rt2x00dev,
void rt2800_gain_calibration(struct rt2x00_dev *rt2x00dev)
{
- rt2800_config_txpower(rt2x00dev, rt2x00dev->curr_band,
+ rt2800_config_txpower(rt2x00dev, rt2x00dev->hw->conf.channel,
rt2x00dev->tx_power);
}
EXPORT_SYMBOL_GPL(rt2800_gain_calibration);
@@ -2845,11 +2899,11 @@ void rt2800_config(struct rt2x00_dev *rt2x00dev,
if (flags & IEEE80211_CONF_CHANGE_CHANNEL) {
rt2800_config_channel(rt2x00dev, libconf->conf,
&libconf->rf, &libconf->channel);
- rt2800_config_txpower(rt2x00dev, libconf->conf->channel->band,
+ rt2800_config_txpower(rt2x00dev, libconf->conf->channel,
libconf->conf->power_level);
}
if (flags & IEEE80211_CONF_CHANGE_POWER)
- rt2800_config_txpower(rt2x00dev, libconf->conf->channel->band,
+ rt2800_config_txpower(rt2x00dev, libconf->conf->channel,
libconf->conf->power_level);
if (flags & IEEE80211_CONF_CHANGE_RETRY_LIMITS)
rt2800_config_retry_limit(rt2x00dev, libconf);