1 files changed, 562 insertions, 13 deletions

diff --git a/drivers/net/wireless/iwlwifi/iwl-4965-hw.h b/drivers/net/wireless/iwlwifi/iwl-4965-hw.h
index 78d9854f7506..4a2fa80acff7 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965-hw.h
+++ b/drivers/net/wireless/iwlwifi/iwl-4965-hw.h
@@ -647,7 +647,7 @@ static inline int iwl4965_hw_valid_rtc_data_addr(u32 addr)
 
 /********************* START TEMPERATURE *************************************/
 
-/*
+/**
  * 4965 temperature calculation.
  *
  * The driver must calculate the device temperature before calculating
@@ -693,44 +693,593 @@ static inline int iwl4965_hw_valid_rtc_data_addr(u32 addr)
 
 /********************* START TXPOWER *****************************************/
 
-enum {
-        CALIB_CH_GROUP_1 = 0,
-        CALIB_CH_GROUP_2 = 1,
-        CALIB_CH_GROUP_3 = 2,
-        CALIB_CH_GROUP_4 = 3,
-        CALIB_CH_GROUP_5 = 4,
-        CALIB_CH_GROUP_MAX
-};
+/**
+ * 4965 txpower calculations rely on information from three sources:
+ *
+ *     1) EEPROM
+ *     2) "initialize" alive notification
+ *     3) statistics notifications
+ *
+ * EEPROM data consists of:
+ *
+ * 1)  Regulatory information (max txpower and channel usage flags) is provided
+ *     separately for each channel that can possibly supported by 4965.
+ *     40 MHz wide (.11n fat) channels are listed separately from 20 MHz
+ *     (legacy) channels.
+ *
+ *     See struct iwl4965_eeprom_channel for format, and struct iwl4965_eeprom
+ *     for locations in EEPROM.
+ *
+ * 2)  Factory txpower calibration information is provided separately for
+ *     sub-bands of contiguous channels.  2.4GHz has just one sub-band,
+ *     but 5 GHz has several sub-bands.
+ *
+ *     In addition, per-band (2.4 and 5 Ghz) saturation txpowers are provided.
+ *
+ *     See struct iwl4965_eeprom_calib_info (and the tree of structures
+ *     contained within it) for format, and struct iwl4965_eeprom for
+ *     locations in EEPROM.
+ *
+ * "Initialization alive" notification (see struct iwl4965_init_alive_resp)
+ * consists of:
+ *
+ * 1)  Temperature calculation parameters.
+ *
+ * 2)  Power supply voltage measurement.
+ *
+ * 3)  Tx gain compensation to balance 2 transmitters for MIMO use.
+ *
+ * Statistics notifications deliver:
+ *
+ * 1)  Current values for temperature param R4.
+ */
 
-#define IWL_TX_POWER_MIMO_REGULATORY_COMPENSATION (6)
+/**
+ * To calculate a txpower setting for a given desired target txpower, channel,
+ * modulation bit rate, and transmitter chain (4965 has 2 transmitters to
+ * support MIMO and transmit diversity), driver must do the following:
+ *
+ * 1)  Compare desired txpower vs. (EEPROM) regulatory limit for this channel.
+ *     Do not exceed regulatory limit; reduce target txpower if necessary.
+ *
+ *     If setting up txpowers for MIMO rates (rate indexes 8-15, 24-31),
+ *     2 transmitters will be used simultaneously; driver must reduce the
+ *     regulatory limit by 3 dB (half-power) for each transmitter, so the
+ *     combined total output of the 2 transmitters is within regulatory limits.
+ *
+ *
+ * 2)  Compare target txpower vs. (EEPROM) saturation txpower *reduced by
+ *     backoff for this bit rate*.  Do not exceed (saturation - backoff[rate]);
+ *     reduce target txpower if necessary.
+ *
+ *     Backoff values below are in 1/2 dB units (equivalent to steps in
+ *     txpower gain tables):
+ *
+ *     OFDM 6 - 36 MBit:  10 steps (5 dB)
+ *     OFDM 48 MBit:      15 steps (7.5 dB)
+ *     OFDM 54 MBit:      17 steps (8.5 dB)
+ *     OFDM 60 MBit:      20 steps (10 dB)
+ *     CCK all rates:     10 steps (5 dB)
+ *
+ *     Backoff values apply to saturation txpower on a per-transmitter basis;
+ *     when using MIMO (2 transmitters), each transmitter uses the same
+ *     saturation level provided in EEPROM, and the same backoff values;
+ *     no reduction (such as with regulatory txpower limits) is required.
+ *
+ *     Saturation and Backoff values apply equally to 20 Mhz (legacy) channel
+ *     widths and 40 Mhz (.11n fat) channel widths; there is no separate
+ *     factory measurement for fat channels.
+ *
+ *     The result of this step is the final target txpower.  The rest of
+ *     the steps figure out the proper settings for the device to achieve
+ *     that target txpower.
+ *
+ *
+ * 3)  Determine (EEPROM) calibration subband for the target channel, by
+ *     comparing against first and last channels in each subband
+ *     (see struct iwl4965_eeprom_calib_subband_info).
+ *
+ *
+ * 4)  Linearly interpolate (EEPROM) factory calibration measurement sets,
+ *     referencing the 2 factory-measured (sample) channels within the subband.
+ *
+ *     Interpolation is based on difference between target channel's frequency
+ *     and the sample channels' frequencies.  Since channel numbers are based
+ *     on frequency (5 MHz between each channel number), this is equivalent
+ *     to interpolating based on channel number differences.
+ *
+ *     Note that the sample channels may or may not be the channels at the
+ *     edges of the subband.  The target channel may be "outside" of the
+ *     span of the sampled channels.
+ *
+ *     Driver may choose the pair (for 2 Tx chains) of measurements (see
+ *     struct iwl4965_eeprom_calib_ch_info) for which the actual measured
+ *     txpower comes closest to the desired txpower.  Usually, though,
+ *     the middle set of measurements is closest to the regulatory limits,
+ *     and is therefore a good choice for all txpower calculations (this
+ *     assumes that high accuracy is needed for maximizing legal txpower,
+ *     while lower txpower configurations do not need as much accuracy).
+ *
+ *     Driver should interpolate both members of the chosen measurement pair,
+ *     i.e. for both Tx chains (radio transmitters), unless the driver knows
+ *     that only one of the chains will be used (e.g. only one tx antenna
+ *     connected, but this should be unusual).  The rate scaling algorithm
+ *     switches antennas to find best performance, so both Tx chains will
+ *     be used (although only one at a time) even for non-MIMO transmissions.
+ *
+ *     Driver should interpolate factory values for temperature, gain table
+ *     index, and actual power.  The power amplifier detector values are
+ *     not used by the driver.
+ *
+ *     Sanity check:  If the target channel happens to be one of the sample
+ *     channels, the results should agree with the sample channel's
+ *     measurements!
+ *
+ *
+ * 5)  Find difference between desired txpower and (interpolated)
+ *     factory-measured txpower.  Using (interpolated) factory gain table index
+ *     (shown elsewhere) as a starting point, adjust this index lower to
+ *     increase txpower, or higher to decrease txpower, until the target
+ *     txpower is reached.  Each step in the gain table is 1/2 dB.
+ *
+ *     For example, if factory measured txpower is 16 dBm, and target txpower
+ *     is 13 dBm, add 6 steps to the factory gain index to reduce txpower
+ *     by 3 dB.
+ *
+ *
+ * 6)  Find difference between current device temperature and (interpolated)
+ *     factory-measured temperature for sub-band.  Factory values are in
+ *     degrees Celsius.  To calculate current temperature, see comments for
+ *     "4965 temperature calculation".
+ *
+ *     If current temperature is higher than factory temperature, driver must
+ *     increase gain (lower gain table index), and vice versa.
+ *
+ *     Temperature affects gain differently for different channels:
+ *
+ *     2.4 GHz all channels:  3.5 degrees per half-dB step
+ *     5 GHz channels 34-43:  4.5 degrees per half-dB step
+ *     5 GHz channels >= 44:  4.0 degrees per half-dB step
+ *
+ *     NOTE:  Temperature can increase rapidly when transmitting, especially
+ *            with heavy traffic at high txpowers.  Driver should update
+ *            temperature calculations often under these conditions to
+ *            maintain strong txpower in the face of rising temperature.
+ *
+ *
+ * 7)  Find difference between current power supply voltage indicator
+ *     (from "initialize alive") and factory-measured power supply voltage
+ *     indicator (EEPROM).
+ *
+ *     If the current voltage is higher (indicator is lower) than factory
+ *     voltage, gain should be reduced (gain table index increased) by:
+ *
+ *     (eeprom - current) / 7
+ *
+ *     If the current voltage is lower (indicator is higher) than factory
+ *     voltage, gain should be increased (gain table index decreased) by:
+ *
+ *     2 * (current - eeprom) / 7
+ *
+ *     If number of index steps in either direction turns out to be > 2,
+ *     something is wrong ... just use 0.
+ *
+ *     NOTE:  Voltage compensation is independent of band/channel.
+ *
+ *     NOTE:  "Initialize" uCode measures current voltage, which is assumed
+ *            to be constant after this initial measurement.  Voltage
+ *            compensation for txpower (number of steps in gain table)
+ *            may be calculated once and used until the next uCode bootload.
+ *
+ *
+ * 8)  If setting up txpowers for MIMO rates (rate indexes 8-15, 24-31),
+ *     adjust txpower for each transmitter chain, so txpower is balanced
+ *     between the two chains.  There are 5 pairs of tx_atten[group][chain]
+ *     values in "initialize alive", one pair for each of 5 channel ranges:
+ *
+ *     Group 0:  5 GHz channel 34-43
+ *     Group 1:  5 GHz channel 44-70
+ *     Group 2:  5 GHz channel 71-124
+ *     Group 3:  5 GHz channel 125-200
+ *     Group 4:  2.4 GHz all channels
+ *
+ *     Add the tx_atten[group][chain] value to the index for the target chain.
+ *     The values are signed, but are in pairs of 0 and a non-negative number,
+ *     so as to reduce gain (if necessary) of the "hotter" channel.  This
+ *     avoids any need to double-check for regulatory compliance after
+ *     this step.
+ *
+ *
+ * 9)  If setting up for a CCK rate, lower the gain by adding a CCK compensation
+ *     value to the index:
+ *
+ *     Hardware rev B:  9 steps (4.5 dB)
+ *     Hardware rev C:  5 steps (2.5 dB)
+ *
+ *     Hardware rev for 4965 can be determined by reading CSR_HW_REV_WA_REG,
+ *     bits [3:2], 1 = B, 2 = C.
+ *
+ *     NOTE:  This compensation is in addition to any saturation backoff that
+ *            might have been applied in an earlier step.
+ *
+ *
+ * 10) Select the gain table, based on band (2.4 vs 5 GHz).
+ *
+ *     Limit the adjusted index to stay within the table!
+ *
+ *
+ * 11) Read gain table entries for DSP and radio gain, place into appropriate
+ *     location(s) in command (struct iwl4965_txpowertable_cmd).
+ */
 
+/* Limit range of txpower output target to be between these values */
 #define IWL_TX_POWER_TARGET_POWER_MIN       (0) /* 0 dBm = 1 milliwatt */
 #define IWL_TX_POWER_TARGET_POWER_MAX      (16) /* 16 dBm */
 
-#define MIN_TX_GAIN_INDEX               (0)
-#define MIN_TX_GAIN_INDEX_52GHZ_EXT     (-9)
+/**
+ * When MIMO is used (2 transmitters operating simultaneously), driver should
+ * limit each transmitter to deliver a max of 3 dB below the regulatory limit
+ * for the device.  That is, use half power for each transmitter, so total
+ * txpower is within regulatory limits.
+ *
+ * The value "6" represents number of steps in gain table to reduce power 3 dB.
+ * Each step is 1/2 dB.
+ */
+#define IWL_TX_POWER_MIMO_REGULATORY_COMPENSATION (6)
+
+/**
+ * CCK gain compensation.
+ *
+ * When calculating txpowers for CCK, after making sure that the target power
+ * is within regulatory and saturation limits, driver must additionally
+ * back off gain by adding these values to the gain table index.
+ *
+ * Hardware rev for 4965 can be determined by reading CSR_HW_REV_WA_REG,
+ * bits [3:2], 1 = B, 2 = C.
+ */
+#define IWL_TX_POWER_CCK_COMPENSATION_B_STEP (9)
+#define IWL_TX_POWER_CCK_COMPENSATION_C_STEP (5)
+
+/*
+ * 4965 power supply voltage compensation for txpower
+ */
+#define TX_POWER_IWL_VOLTAGE_CODES_PER_03V   (7)
+
+/**
+ * Gain tables.
+ *
+ * The following tables contain pair of values for setting txpower, i.e.
+ * gain settings for the output of the device's digital signal processor (DSP),
+ * and for the analog gain structure of the transmitter.
+ *
+ * Each entry in the gain tables represents a step of 1/2 dB.  Note that these
+ * are *relative* steps, not indications of absolute output power.  Output
+ * power varies with temperature, voltage, and channel frequency, and also
+ * requires consideration of average power (to satisfy regulatory constraints),
+ * and peak power (to avoid distortion of the output signal).
+ *
+ * Each entry contains two values:
+ * 1)  DSP gain (or sometimes called DSP attenuation).  This is a fine-grained
+ *     linear value that multiplies the output of the digital signal processor,
+ *     before being sent to the analog radio.
+ * 2)  Radio gain.  This sets the analog gain of the radio Tx path.
+ *     It is a coarser setting, and behaves in a logarithmic (dB) fashion.
+ *
+ * EEPROM contains factory calibration data for txpower.  This maps actual
+ * measured txpower levels to gain settings in the "well known" tables
+ * below ("well-known" means here that both factory calibration *and* the
+ * driver work with the same table).
+ *
+ * There are separate tables for 2.4 GHz and 5 GHz bands.  The 5 GHz table
+ * has an extension (into negative indexes), in case the driver needs to
+ * boost power setting for high device temperatures (higher than would be
+ * present during factory calibration).  A 5 Ghz EEPROM index of "40"
+ * corresponds to the 49th entry in the table used by the driver.
+ */
+#define MIN_TX_GAIN_INDEX               (0)  /* highest gain, lowest idx, 2.4 */
+#define MIN_TX_GAIN_INDEX_52GHZ_EXT     (-9) /* highest gain, lowest idx, 5 */
+
+/**
+ * 2.4 GHz gain table
+ *
+ * Index    Dsp gain   Radio gain
+ *   0        110         0x3f      (highest gain)
+ *   1        104         0x3f
+ *   2         98         0x3f
+ *   3        110         0x3e
+ *   4        104         0x3e
+ *   5         98         0x3e
+ *   6        110         0x3d
+ *   7        104         0x3d
+ *   8         98         0x3d
+ *   9        110         0x3c
+ *  10        104         0x3c
+ *  11         98         0x3c
+ *  12        110         0x3b
+ *  13        104         0x3b
+ *  14         98         0x3b
+ *  15        110         0x3a
+ *  16        104         0x3a
+ *  17         98         0x3a
+ *  18        110         0x39
+ *  19        104         0x39
+ *  20         98         0x39
+ *  21        110         0x38
+ *  22        104         0x38
+ *  23         98         0x38
+ *  24        110         0x37
+ *  25        104         0x37
+ *  26         98         0x37
+ *  27        110         0x36
+ *  28        104         0x36
+ *  29         98         0x36
+ *  30        110         0x35
+ *  31        104         0x35
+ *  32         98         0x35
+ *  33        110         0x34
+ *  34        104         0x34
+ *  35         98         0x34
+ *  36        110         0x33
+ *  37        104         0x33
+ *  38         98         0x33
+ *  39        110         0x32
+ *  40        104         0x32
+ *  41         98         0x32
+ *  42        110         0x31
+ *  43        104         0x31
+ *  44         98         0x31
+ *  45        110         0x30
+ *  46        104         0x30
+ *  47         98         0x30
+ *  48        110          0x6
+ *  49        104          0x6
+ *  50         98          0x6
+ *  51        110          0x5
+ *  52        104          0x5
+ *  53         98          0x5
+ *  54        110          0x4
+ *  55        104          0x4
+ *  56         98          0x4
+ *  57        110          0x3
+ *  58        104          0x3
+ *  59         98          0x3
+ *  60        110          0x2
+ *  61        104          0x2
+ *  62         98          0x2
+ *  63        110          0x1
+ *  64        104          0x1
+ *  65         98          0x1
+ *  66        110          0x0
+ *  67        104          0x0
+ *  68         98          0x0
+ *  69         97            0
+ *  70         96            0
+ *  71         95            0
+ *  72         94            0
+ *  73         93            0
+ *  74         92            0
+ *  75         91            0
+ *  76         90            0
+ *  77         89            0
+ *  78         88            0
+ *  79         87            0
+ *  80         86            0
+ *  81         85            0
+ *  82         84            0
+ *  83         83            0
+ *  84         82            0
+ *  85         81            0
+ *  86         80            0
+ *  87         79            0
+ *  88         78            0
+ *  89         77            0
+ *  90         76            0
+ *  91         75            0
+ *  92         74            0
+ *  93         73            0
+ *  94         72            0
+ *  95         71            0
+ *  96         70            0
+ *  97         69            0
+ *  98         68            0
+ */
+
+/**
+ * 5 GHz gain table
+ *
+ * Index    Dsp gain   Radio gain
+ *  -9        123         0x3F      (highest gain)
+ *  -8        117         0x3F
+ *  -7        110         0x3F
+ *  -6        104         0x3F
+ *  -5         98         0x3F
+ *  -4        110         0x3E
+ *  -3        104         0x3E
+ *  -2         98         0x3E
+ *  -1        110         0x3D
+ *   0        104         0x3D
+ *   1         98         0x3D
+ *   2        110         0x3C
+ *   3        104         0x3C
+ *   4         98         0x3C
+ *   5        110         0x3B
+ *   6        104         0x3B
+ *   7         98         0x3B
+ *   8        110         0x3A
+ *   9        104         0x3A
+ *  10         98         0x3A
+ *  11        110         0x39
+ *  12        104         0x39
+ *  13         98         0x39
+ *  14        110         0x38
+ *  15        104         0x38
+ *  16         98         0x38
+ *  17        110         0x37
+ *  18        104         0x37
+ *  19         98         0x37
+ *  20        110         0x36
+ *  21        104         0x36
+ *  22         98         0x36
+ *  23        110         0x35
+ *  24        104         0x35
+ *  25         98         0x35
+ *  26        110         0x34
+ *  27        104         0x34
+ *  28         98         0x34
+ *  29        110         0x33
+ *  30        104         0x33
+ *  31         98         0x33
+ *  32        110         0x32
+ *  33        104         0x32
+ *  34         98         0x32
+ *  35        110         0x31
+ *  36        104         0x31
+ *  37         98         0x31
+ *  38        110         0x30
+ *  39        104         0x30
+ *  40         98         0x30
+ *  41        110         0x25
+ *  42        104         0x25
+ *  43         98         0x25
+ *  44        110         0x24
+ *  45        104         0x24
+ *  46         98         0x24
+ *  47        110         0x23
+ *  48        104         0x23
+ *  49         98         0x23
+ *  50        110         0x22
+ *  51        104         0x18
+ *  52         98         0x18
+ *  53        110         0x17
+ *  54        104         0x17
+ *  55         98         0x17
+ *  56        110         0x16
+ *  57        104         0x16
+ *  58         98         0x16
+ *  59        110         0x15
+ *  60        104         0x15
+ *  61         98         0x15
+ *  62        110         0x14
+ *  63        104         0x14
+ *  64         98         0x14
+ *  65        110         0x13
+ *  66        104         0x13
+ *  67         98         0x13
+ *  68        110         0x12
+ *  69        104         0x08
+ *  70         98         0x08
+ *  71        110         0x07
+ *  72        104         0x07
+ *  73         98         0x07
+ *  74        110         0x06
+ *  75        104         0x06
+ *  76         98         0x06
+ *  77        110         0x05
+ *  78        104         0x05
+ *  79         98         0x05
+ *  80        110         0x04
+ *  81        104         0x04
+ *  82         98         0x04
+ *  83        110         0x03
+ *  84        104         0x03
+ *  85         98         0x03
+ *  86        110         0x02
+ *  87        104         0x02
+ *  88         98         0x02
+ *  89        110         0x01
+ *  90        104         0x01
+ *  91         98         0x01
+ *  92        110         0x00
+ *  93        104         0x00
+ *  94         98         0x00
+ *  95         93         0x00
+ *  96         88         0x00
+ *  97         83         0x00
+ *  98         78         0x00
+ */
 
+
+/**
+ * Sanity checks and default values for EEPROM regulatory levels.
+ * If EEPROM values fall outside MIN/MAX range, use default values.
+ *
+ * Regulatory limits refer to the maximum average txpower allowed by
+ * regulatory agencies in the geographies in which the device is meant
+ * to be operated.  These limits are SKU-specific (i.e. geography-specific),
+ * and channel-specific; each channel has an individual regulatory limit
+ * listed in the EEPROM.
+ *
+ * Units are in half-dBm (i.e. "34" means 17 dBm).
+ */
 #define IWL_TX_POWER_DEFAULT_REGULATORY_24   (34)
 #define IWL_TX_POWER_DEFAULT_REGULATORY_52   (34)
 #define IWL_TX_POWER_REGULATORY_MIN          (0)
 #define IWL_TX_POWER_REGULATORY_MAX          (34)
+
+/**
+ * Sanity checks and default values for EEPROM saturation levels.
+ * If EEPROM values fall outside MIN/MAX range, use default values.
+ *
+ * Saturation is the highest level that the output power amplifier can produce
+ * without significant clipping distortion.  This is a "peak" power level.
+ * Different types of modulation (i.e. various "rates", and OFDM vs. CCK)
+ * require differing amounts of backoff, relative to their average power output,
+ * in order to avoid clipping distortion.
+ *
+ * Driver must make sure that it is violating neither the saturation limit,
+ * nor the regulatory limit, when calculating Tx power settings for various
+ * rates.
+ *
+ * Units are in half-dBm (i.e. "38" means 19 dBm).
+ */
 #define IWL_TX_POWER_DEFAULT_SATURATION_24   (38)
 #define IWL_TX_POWER_DEFAULT_SATURATION_52   (38)
 #define IWL_TX_POWER_SATURATION_MIN          (20)
 #define IWL_TX_POWER_SATURATION_MAX          (50)
 
-/* First and last channels of all groups */
+/**
+ * Channel groups used for Tx Attenuation calibration (MIMO tx channel balance)
+ * and thermal Txpower calibration.
+ *
+ * When calculating txpower, driver must compensate for current device
+ * temperature; higher temperature requires higher gain.  Driver must calculate
+ * current temperature (see "4965 temperature calculation"), then compare vs.
+ * factory calibration temperature in EEPROM; if current temperature is higher
+ * than factory temperature, driver must *increase* gain by proportions shown
+ * in table below.  If current temperature is lower than factory, driver must
+ * *decrease* gain.
+ *
+ * Different frequency ranges require different compensation, as shown below.
+ */
+/* Group 0, 5.2 GHz ch 34-43:  4.5 degrees per 1/2 dB. */
 #define CALIB_IWL_TX_ATTEN_GR1_FCH 34
 #define CALIB_IWL_TX_ATTEN_GR1_LCH 43
+
+/* Group 1, 5.3 GHz ch 44-70:  4.0 degrees per 1/2 dB. */
 #define CALIB_IWL_TX_ATTEN_GR2_FCH 44
 #define CALIB_IWL_TX_ATTEN_GR2_LCH 70
+
+/* Group 2, 5.5 GHz ch 71-124:  4.0 degrees per 1/2 dB. */
 #define CALIB_IWL_TX_ATTEN_GR3_FCH 71
 #define CALIB_IWL_TX_ATTEN_GR3_LCH 124
+
+/* Group 3, 5.7 GHz ch 125-200:  4.0 degrees per 1/2 dB. */
 #define CALIB_IWL_TX_ATTEN_GR4_FCH 125
 #define CALIB_IWL_TX_ATTEN_GR4_LCH 200
+
+/* Group 4, 2.4 GHz all channels:  3.5 degrees per 1/2 dB. */
 #define CALIB_IWL_TX_ATTEN_GR5_FCH 1
 #define CALIB_IWL_TX_ATTEN_GR5_LCH 20
 
+enum {
+        CALIB_CH_GROUP_1 = 0,
+        CALIB_CH_GROUP_2 = 1,
+        CALIB_CH_GROUP_3 = 2,
+        CALIB_CH_GROUP_4 = 3,
+        CALIB_CH_GROUP_5 = 4,
+        CALIB_CH_GROUP_MAX
+};
+
 /********************* END TXPOWER *****************************************/
 
 /* Flow Handler Definitions */