Search Linux Wireless

[PATCH 05/34] iwlwifi: add comments to EEPROM stuff

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



From: Ben Cahill <ben.m.cahill@xxxxxxxxx>

Add comments to EEPROM stuff.

Signed-off-by: Ben Cahill <ben.m.cahill@xxxxxxxxx>
Signed-off-by: Zhu Yi <yi.zhu@xxxxxxxxx>
---
 drivers/net/wireless/iwlwifi/iwl-3945-hw.h |   94 +++++++++++--
 drivers/net/wireless/iwlwifi/iwl-3945.c    |    9 ++
 drivers/net/wireless/iwlwifi/iwl-4965-hw.h |  209 +++++++++++++++++++++++++---
 drivers/net/wireless/iwlwifi/iwl-4965.c    |    9 ++
 4 files changed, 285 insertions(+), 36 deletions(-)

diff --git a/drivers/net/wireless/iwlwifi/iwl-3945-hw.h b/drivers/net/wireless/iwlwifi/iwl-3945-hw.h
index a5e783c..6351df9 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945-hw.h
+++ b/drivers/net/wireless/iwlwifi/iwl-3945-hw.h
@@ -85,24 +85,48 @@
 #define IWL_RSSI_OFFSET	95
 
 /*
- * This file defines EEPROM related constants, enums, and inline functions.
- *
+ * EEPROM related constants, enums, and structures.
  */
 
+/*
+ * EEPROM access time values:
+ *
+ * Driver initiates EEPROM read by writing byte address << 1 to CSR_EEPROM_REG,
+ *   then clearing (with subsequent read/modify/write) CSR_EEPROM_REG bit
+ *   CSR_EEPROM_REG_BIT_CMD (0x2).
+ * Driver then polls CSR_EEPROM_REG for CSR_EEPROM_REG_READ_VALID_MSK (0x1).
+ * When polling, wait 10 uSec between polling loops, up to a maximum 5000 uSec.
+ * Driver reads 16-bit value from bits 31-16 of CSR_EEPROM_REG.
+ */
 #define IWL_EEPROM_ACCESS_TIMEOUT	5000 /* uSec */
 #define IWL_EEPROM_ACCESS_DELAY		10   /* uSec */
+
 /* EEPROM field values */
 #define ANTENNA_SWITCH_NORMAL     0
 #define ANTENNA_SWITCH_INVERSE    1
 
+/*
+ * Regulatory channel usage flags in EEPROM struct iwl_eeprom_channel.flags.
+ *
+ * IBSS and/or AP operation is allowed *only* on those channels with
+ * (VALID && IBSS && ACTIVE && !RADAR).  This restriction is in place because
+ * RADAR detection is not supported by the 3945 driver, but is a
+ * requirement for establishing a new network for legal operation on channels
+ * requiring RADAR detection or restricting ACTIVE scanning.
+ *
+ * NOTE:  "WIDE" flag indicates that 20 MHz channel is supported;
+ *        3945 does not support FAT 40 MHz-wide channels.
+ *
+ * NOTE:  Using a channel inappropriately will result in a uCode error!
+ */
 enum {
 	EEPROM_CHANNEL_VALID = (1 << 0),	/* usable for this SKU/geo */
-	EEPROM_CHANNEL_IBSS = (1 << 1),	/* usable as an IBSS channel */
+	EEPROM_CHANNEL_IBSS = (1 << 1),		/* usable as an IBSS channel */
 	/* Bit 2 Reserved */
 	EEPROM_CHANNEL_ACTIVE = (1 << 3),	/* active scanning allowed */
 	EEPROM_CHANNEL_RADAR = (1 << 4),	/* radar detection required */
-	EEPROM_CHANNEL_WIDE = (1 << 5),
-	EEPROM_CHANNEL_NARROW = (1 << 6),
+	EEPROM_CHANNEL_WIDE = (1 << 5),		/* 20 MHz channel okay */
+	EEPROM_CHANNEL_NARROW = (1 << 6),	/* 10 MHz channel, not used */
 	EEPROM_CHANNEL_DFS = (1 << 7),	/* dynamic freq selection candidate */
 };
 
@@ -147,6 +171,7 @@ struct iwl3945_eeprom_channel {
  *   long packets in normal operation to provide feedback as to proper output
  *   level.
  * Data copied from EEPROM.
+ * DO NOT ALTER THIS STRUCTURE!!!
  */
 struct iwl3945_eeprom_txpower_sample {
 	u8 gain_index;		/* index into power (gain) setup table ... */
@@ -163,11 +188,11 @@ struct iwl3945_eeprom_txpower_sample {
  * DO NOT ALTER THIS STRUCTURE!!!
  */
 struct iwl3945_eeprom_txpower_group {
-	struct iwl3945_eeprom_txpower_sample samples[5];	/* 5 power levels */
+	struct iwl3945_eeprom_txpower_sample samples[5];  /* 5 power levels */
 	s32 a, b, c, d, e;	/* coefficients for voltage->power
 				 * formula (signed) */
 	s32 Fa, Fb, Fc, Fd, Fe;	/* these modify coeffs based on
-					 * frequency (signed) */
+				 * frequency (signed) */
 	s8 saturation_power;	/* highest power possible by h/w in this
 				 * band */
 	u8 group_channel;	/* "representative" channel # in this band */
@@ -189,6 +214,9 @@ struct iwl3945_eeprom_temperature_corr {
 	u32 Te;
 } __attribute__ ((packed));
 
+/*
+ * EEPROM map
+ */
 struct iwl3945_eeprom {
 	u8 reserved0[16];
 #define EEPROM_DEVICE_ID                    (2*0x08)	/* 2 bytes */
@@ -229,29 +257,67 @@ struct iwl3945_eeprom {
 	u8 reserved6[42];
 #define EEPROM_REGULATORY_SKU_ID            (2*0x60)	/* 4  bytes */
 	u8 sku_id[4];		/* abs.ofs: 192 */
+
+/*
+ * Per-channel regulatory data.
+ *
+ * Each channel that *might* be supported by 3945 or 4965 has a fixed location
+ * in EEPROM containing EEPROM_CHANNEL_* usage flags (LSB) and max regulatory
+ * txpower (MSB).
+ *
+ * Entries immediately below are for 20 MHz channel width.  FAT (40 MHz)
+ * channels (only for 4965, not supported by 3945) appear later in the EEPROM.
+ *
+ * 2.4 GHz channels 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14
+ */
 #define EEPROM_REGULATORY_BAND_1            (2*0x62)	/* 2  bytes */
 	u16 band_1_count;	/* abs.ofs: 196 */
 #define EEPROM_REGULATORY_BAND_1_CHANNELS   (2*0x63)	/* 28 bytes */
-	struct iwl3945_eeprom_channel band_1_channels[14];	/* abs.ofs: 196 */
+	struct iwl3945_eeprom_channel band_1_channels[14];  /* abs.ofs: 196 */
+
+/*
+ * 4.9 GHz channels 183, 184, 185, 187, 188, 189, 192, 196,
+ * 5.0 GHz channels 7, 8, 11, 12, 16
+ * (4915-5080MHz) (none of these is ever supported)
+ */
 #define EEPROM_REGULATORY_BAND_2            (2*0x71)	/* 2  bytes */
 	u16 band_2_count;	/* abs.ofs: 226 */
 #define EEPROM_REGULATORY_BAND_2_CHANNELS   (2*0x72)	/* 26 bytes */
-	struct iwl3945_eeprom_channel band_2_channels[13];	/* abs.ofs: 228 */
+	struct iwl3945_eeprom_channel band_2_channels[13];  /* abs.ofs: 228 */
+
+/*
+ * 5.2 GHz channels 34, 36, 38, 40, 42, 44, 46, 48, 52, 56, 60, 64
+ * (5170-5320MHz)
+ */
 #define EEPROM_REGULATORY_BAND_3            (2*0x7F)	/* 2  bytes */
 	u16 band_3_count;	/* abs.ofs: 254 */
 #define EEPROM_REGULATORY_BAND_3_CHANNELS   (2*0x80)	/* 24 bytes */
-	struct iwl3945_eeprom_channel band_3_channels[12];	/* abs.ofs: 256 */
+	struct iwl3945_eeprom_channel band_3_channels[12];  /* abs.ofs: 256 */
+
+/*
+ * 5.5 GHz channels 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140
+ * (5500-5700MHz)
+ */
 #define EEPROM_REGULATORY_BAND_4            (2*0x8C)	/* 2  bytes */
 	u16 band_4_count;	/* abs.ofs: 280 */
 #define EEPROM_REGULATORY_BAND_4_CHANNELS   (2*0x8D)	/* 22 bytes */
-	struct iwl3945_eeprom_channel band_4_channels[11];	/* abs.ofs: 282 */
+	struct iwl3945_eeprom_channel band_4_channels[11];  /* abs.ofs: 282 */
+
+/*
+ * 5.7 GHz channels 145, 149, 153, 157, 161, 165
+ * (5725-5825MHz)
+ */
 #define EEPROM_REGULATORY_BAND_5            (2*0x98)	/* 2  bytes */
 	u16 band_5_count;	/* abs.ofs: 304 */
 #define EEPROM_REGULATORY_BAND_5_CHANNELS   (2*0x99)	/* 12 bytes */
-	struct iwl3945_eeprom_channel band_5_channels[6];	/* abs.ofs: 306 */
+	struct iwl3945_eeprom_channel band_5_channels[6];  /* abs.ofs: 306 */
 
 	u8 reserved9[194];
 
+
+/*
+ * 3945 Txpower calibration data.
+ */
 #define EEPROM_TXPOWER_CALIB_GROUP0 0x200
 #define EEPROM_TXPOWER_CALIB_GROUP1 0x240
 #define EEPROM_TXPOWER_CALIB_GROUP2 0x280
@@ -261,12 +327,14 @@ struct iwl3945_eeprom {
 	struct iwl3945_eeprom_txpower_group groups[IWL_NUM_TX_CALIB_GROUPS];
 /* abs.ofs: 512 */
 #define EEPROM_CALIB_TEMPERATURE_CORRECT 0x340
-	struct iwl3945_eeprom_temperature_corr corrections;	/* abs.ofs: 832 */
+	struct iwl3945_eeprom_temperature_corr corrections;  /* abs.ofs: 832 */
 	u8 reserved16[172];	/* fill out to full 1024 byte block */
 } __attribute__ ((packed));
 
 #define IWL_EEPROM_IMAGE_SIZE 1024
 
+/* End of EEPROM */
+
 
 #include "iwl-3945-commands.h"
 
diff --git a/drivers/net/wireless/iwlwifi/iwl-3945.c b/drivers/net/wireless/iwlwifi/iwl-3945.c
index 3de88b0..b58bcc2 100644
--- a/drivers/net/wireless/iwlwifi/iwl-3945.c
+++ b/drivers/net/wireless/iwlwifi/iwl-3945.c
@@ -2202,6 +2202,7 @@ int iwl3945_init_hw_rate_table(struct iwl3945_priv *priv)
 				&rate_cmd);
 }
 
+/* Called when initializing driver */
 int iwl3945_hw_set_hw_setting(struct iwl3945_priv *priv)
 {
 	memset((void *)&priv->hw_setting, 0,
@@ -2285,6 +2286,14 @@ struct pci_device_id iwl3945_hw_card_ids[] = {
 	{0}
 };
 
+/*
+ * Clear the OWNER_MSK, to establish driver (instead of uCode running on
+ * embedded controller) as EEPROM reader; each read is a series of pulses
+ * to/from the EEPROM chip, not a single event, so even reads could conflict
+ * if they weren't arbitrated by some ownership mechanism.  Here, the driver
+ * simply claims ownership, which should be safe when this function is called
+ * (i.e. before loading uCode!).
+ */
 inline int iwl3945_eeprom_acquire_semaphore(struct iwl3945_priv *priv)
 {
 	_iwl3945_clear_bit(priv, CSR_EEPROM_GP, CSR_EEPROM_GP_IF_OWNER_MSK);
diff --git a/drivers/net/wireless/iwlwifi/iwl-4965-hw.h b/drivers/net/wireless/iwlwifi/iwl-4965-hw.h
index 0d3f632..381ca93 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965-hw.h
+++ b/drivers/net/wireless/iwlwifi/iwl-4965-hw.h
@@ -85,24 +85,50 @@
 #define IWL_RSSI_OFFSET	44
 
 /*
- * This file defines EEPROM related constants, enums, and inline functions.
- *
+ * EEPROM related constants, enums, and structures.
  */
 
+/*
+ * EEPROM access time values:
+ *
+ * Driver initiates EEPROM read by writing byte address << 1 to CSR_EEPROM_REG,
+ *   then clearing (with subsequent read/modify/write) CSR_EEPROM_REG bit
+ *   CSR_EEPROM_REG_BIT_CMD (0x2).
+ * Driver then polls CSR_EEPROM_REG for CSR_EEPROM_REG_READ_VALID_MSK (0x1).
+ * When polling, wait 10 uSec between polling loops, up to a maximum 5000 uSec.
+ * Driver reads 16-bit value from bits 31-16 of CSR_EEPROM_REG.
+ */
 #define IWL_EEPROM_ACCESS_TIMEOUT	5000 /* uSec */
 #define IWL_EEPROM_ACCESS_DELAY		10   /* uSec */
+
 /* EEPROM field values */
 #define ANTENNA_SWITCH_NORMAL     0
 #define ANTENNA_SWITCH_INVERSE    1
 
+/*
+ * Regulatory channel usage flags in EEPROM struct iwl4965_eeprom_channel.flags.
+ *
+ * IBSS and/or AP operation is allowed *only* on those channels with
+ * (VALID && IBSS && ACTIVE && !RADAR).  This restriction is in place because
+ * RADAR detection is not supported by the 4965 driver, but is a
+ * requirement for establishing a new network for legal operation on channels
+ * requiring RADAR detection or restricting ACTIVE scanning.
+ *
+ * NOTE:  "WIDE" flag does not indicate anything about "FAT" 40 MHz channels.
+ *        It only indicates that 20 MHz channel use is supported; FAT channel
+ *        usage is indicated by a separate set of regulatory flags for each
+ *        FAT channel pair.
+ *
+ * NOTE:  Using a channel inappropriately will result in a uCode error!
+ */
 enum {
 	EEPROM_CHANNEL_VALID = (1 << 0),	/* usable for this SKU/geo */
-	EEPROM_CHANNEL_IBSS = (1 << 1),	/* usable as an IBSS channel */
+	EEPROM_CHANNEL_IBSS = (1 << 1),		/* usable as an IBSS channel */
 	/* Bit 2 Reserved */
 	EEPROM_CHANNEL_ACTIVE = (1 << 3),	/* active scanning allowed */
 	EEPROM_CHANNEL_RADAR = (1 << 4),	/* radar detection required */
-	EEPROM_CHANNEL_WIDE = (1 << 5),
-	EEPROM_CHANNEL_NARROW = (1 << 6),
+	EEPROM_CHANNEL_WIDE = (1 << 5),		/* 20 MHz channel okay */
+	EEPROM_CHANNEL_NARROW = (1 << 6),	/* 10 MHz channel, not used */
 	EEPROM_CHANNEL_DFS = (1 << 7),	/* dynamic freq selection candidate */
 };
 
@@ -136,9 +162,10 @@ enum {
 #define EEPROM_SKU_CAP_HW_RF_KILL_ENABLE                (1 << 1)
 #define EEPROM_SKU_CAP_OP_MODE_MRC                      (1 << 7)
 
-/* *regulatory* channel data from eeprom, one for each channel */
+/* *regulatory* channel data format in eeprom, one for each channel.
+ * There are separate entries for FAT (40 MHz) vs. normal (20 MHz) channels. */
 struct iwl4965_eeprom_channel {
-	u8 flags;		/* flags copied from EEPROM */
+	u8 flags;		/* EEPROM_CHANNEL_* flags copied from EEPROM */
 	s8 max_power_avg;	/* max power (dBm) on this chnl, limit 31 */
 } __attribute__ ((packed));
 
@@ -193,44 +220,112 @@ struct iwl4965_eeprom_temperature_corr {
 	u32 Te;
 } __attribute__ ((packed));
 
+/* 4965 has two radio transmitters (and 3 radio receivers) */
 #define EEPROM_TX_POWER_TX_CHAINS      (2)
+
+/* 4965 has room for up to 8 sets of txpower calibration data */
 #define EEPROM_TX_POWER_BANDS          (8)
+
+/* 4965 factory calibration measures txpower gain settings for
+ * each of 3 target output levels */
 #define EEPROM_TX_POWER_MEASUREMENTS   (3)
+
 #define EEPROM_TX_POWER_VERSION        (2)
+
+/* 4965 driver does not work with txpower calibration version < 5.
+ * Look for this in calib_version member of struct iwl4965_eeprom. */
 #define EEPROM_TX_POWER_VERSION_NEW    (5)
 
+
+/*
+ * 4965 factory calibration data for one txpower level, on one channel,
+ * measured on one of the 2 tx chains (radio transmitter and associated
+ * antenna).  EEPROM contains:
+ *
+ * 1)  Temperature (degrees Celsius) of device when measurement was made.
+ *
+ * 2)  Gain table index used to achieve the target measurement power.
+ *     This refers to the "well-known" gain tables (see iwl-4965-hw.h).
+ *
+ * 3)  Actual measured output power, in half-dBm ("34" = 17 dBm).
+ *
+ * 4)  RF power amplifier detector level measurement (not used).
+ */
 struct iwl4965_eeprom_calib_measure {
-	u8 temperature;
-	u8 gain_idx;
-	u8 actual_pow;
-	s8 pa_det;
+	u8 temperature;		/* Device temperature (Celsius) */
+	u8 gain_idx;		/* Index into gain table */
+	u8 actual_pow;		/* Measured RF output power, half-dBm */
+	s8 pa_det;		/* Power amp detector level (not used) */
 } __attribute__ ((packed));
 
+
+/*
+ * 4965 measurement set for one channel.  EEPROM contains:
+ *
+ * 1)  Channel number measured
+ *
+ * 2)  Measurements for each of 3 power levels for each of 2 radio transmitters
+ *     (a.k.a. "tx chains") (6 measurements altogether)
+ */
 struct iwl4965_eeprom_calib_ch_info {
 	u8 ch_num;
 	struct iwl4965_eeprom_calib_measure measurements[EEPROM_TX_POWER_TX_CHAINS]
 		[EEPROM_TX_POWER_MEASUREMENTS];
 } __attribute__ ((packed));
 
+/*
+ * 4965 txpower subband info.
+ *
+ * For each frequency subband, EEPROM contains the following:
+ *
+ * 1)  First and last channels within range of the subband.  "0" values
+ *     indicate that this sample set is not being used.
+ *
+ * 2)  Sample measurement sets for 2 channels close to the range endpoints.
+ */
 struct iwl4965_eeprom_calib_subband_info {
-	u8 ch_from;
-	u8 ch_to;
+	u8 ch_from;	/* channel number of lowest channel in subband */
+	u8 ch_to;	/* channel number of highest channel in subband */
 	struct iwl4965_eeprom_calib_ch_info ch1;
 	struct iwl4965_eeprom_calib_ch_info ch2;
 } __attribute__ ((packed));
 
+
+/*
+ * 4965 txpower calibration info.  EEPROM contains:
+ *
+ * 1)  Factory-measured saturation power levels (maximum levels at which
+ *     tx power amplifier can output a signal without too much distortion).
+ *     There is one level for 2.4 GHz band and one for 5 GHz band.  These
+ *     values apply to all channels within each of the bands.
+ *
+ * 2)  Factory-measured power supply voltage level.  This is assumed to be
+ *     constant (i.e. same value applies to all channels/bands) while the
+ *     factory measurements are being made.
+ *
+ * 3)  Up to 8 sets of factory-measured txpower calibration values.
+ *     These are for different frequency ranges, since txpower gain
+ *     characteristics of the analog radio circuitry vary with frequency.
+ *
+ *     Not all sets need to be filled with data;
+ *     struct iwl4965_eeprom_calib_subband_info contains range of channels
+ *     (0 if unused) for each set of data.
+ */
 struct iwl4965_eeprom_calib_info {
-	u8 saturation_power24;
-	u8 saturation_power52;
+	u8 saturation_power24;	/* half-dBm (e.g. "34" = 17 dBm) */
+	u8 saturation_power52;	/* half-dBm */
 	s16 voltage;		/* signed */
 	struct iwl4965_eeprom_calib_subband_info band_info[EEPROM_TX_POWER_BANDS];
 } __attribute__ ((packed));
 
 
+/*
+ * 4965 EEPROM map
+ */
 struct iwl4965_eeprom {
 	u8 reserved0[16];
 #define EEPROM_DEVICE_ID                    (2*0x08)	/* 2 bytes */
-	u16 device_id;	/* abs.ofs: 16 */
+	u16 device_id;		/* abs.ofs: 16 */
 	u8 reserved1[2];
 #define EEPROM_PMC                          (2*0x0A)	/* 2 bytes */
 	u16 pmc;		/* abs.ofs: 20 */
@@ -273,40 +368,107 @@ struct iwl4965_eeprom {
 	u8 reserved8[10];
 #define EEPROM_REGULATORY_SKU_ID            (2*0x60)	/* 4  bytes */
 	u8 sku_id[4];		/* abs.ofs: 192 */
+
+/*
+ * Per-channel regulatory data.
+ *
+ * Each channel that *might* be supported by 3945 or 4965 has a fixed location
+ * in EEPROM containing EEPROM_CHANNEL_* usage flags (LSB) and max regulatory
+ * txpower (MSB).
+ *
+ * Entries immediately below are for 20 MHz channel width.  FAT (40 MHz)
+ * channels (only for 4965, not supported by 3945) appear later in the EEPROM.
+ *
+ * 2.4 GHz channels 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14
+ */
 #define EEPROM_REGULATORY_BAND_1            (2*0x62)	/* 2  bytes */
 	u16 band_1_count;	/* abs.ofs: 196 */
 #define EEPROM_REGULATORY_BAND_1_CHANNELS   (2*0x63)	/* 28 bytes */
-	struct iwl4965_eeprom_channel band_1_channels[14];	/* abs.ofs: 196 */
+	struct iwl4965_eeprom_channel band_1_channels[14]; /* abs.ofs: 196 */
+
+/*
+ * 4.9 GHz channels 183, 184, 185, 187, 188, 189, 192, 196,
+ * 5.0 GHz channels 7, 8, 11, 12, 16
+ * (4915-5080MHz) (none of these is ever supported)
+ */
 #define EEPROM_REGULATORY_BAND_2            (2*0x71)	/* 2  bytes */
 	u16 band_2_count;	/* abs.ofs: 226 */
 #define EEPROM_REGULATORY_BAND_2_CHANNELS   (2*0x72)	/* 26 bytes */
-	struct iwl4965_eeprom_channel band_2_channels[13];	/* abs.ofs: 228 */
+	struct iwl4965_eeprom_channel band_2_channels[13]; /* abs.ofs: 228 */
+
+/*
+ * 5.2 GHz channels 34, 36, 38, 40, 42, 44, 46, 48, 52, 56, 60, 64
+ * (5170-5320MHz)
+ */
 #define EEPROM_REGULATORY_BAND_3            (2*0x7F)	/* 2  bytes */
 	u16 band_3_count;	/* abs.ofs: 254 */
 #define EEPROM_REGULATORY_BAND_3_CHANNELS   (2*0x80)	/* 24 bytes */
-	struct iwl4965_eeprom_channel band_3_channels[12];	/* abs.ofs: 256 */
+	struct iwl4965_eeprom_channel band_3_channels[12]; /* abs.ofs: 256 */
+
+/*
+ * 5.5 GHz channels 100, 104, 108, 112, 116, 120, 124, 128, 132, 136, 140
+ * (5500-5700MHz)
+ */
 #define EEPROM_REGULATORY_BAND_4            (2*0x8C)	/* 2  bytes */
 	u16 band_4_count;	/* abs.ofs: 280 */
 #define EEPROM_REGULATORY_BAND_4_CHANNELS   (2*0x8D)	/* 22 bytes */
-	struct iwl4965_eeprom_channel band_4_channels[11];	/* abs.ofs: 282 */
+	struct iwl4965_eeprom_channel band_4_channels[11]; /* abs.ofs: 282 */
+
+/*
+ * 5.7 GHz channels 145, 149, 153, 157, 161, 165
+ * (5725-5825MHz)
+ */
 #define EEPROM_REGULATORY_BAND_5            (2*0x98)	/* 2  bytes */
 	u16 band_5_count;	/* abs.ofs: 304 */
 #define EEPROM_REGULATORY_BAND_5_CHANNELS   (2*0x99)	/* 12 bytes */
-	struct iwl4965_eeprom_channel band_5_channels[6];	/* abs.ofs: 306 */
+	struct iwl4965_eeprom_channel band_5_channels[6]; /* abs.ofs: 306 */
 
 	u8 reserved10[2];
+
+
+/*
+ * 2.4 GHz FAT channels 1 (5), 2 (6), 3 (7), 4 (8), 5 (9), 6 (10), 7 (11)
+ *
+ * The channel listed is the center of the lower 20 MHz half of the channel.
+ * The overall center frequency is actually 2 channels (10 MHz) above that,
+ * and the upper half of each FAT channel is centered 4 channels (20 MHz) away
+ * from the lower half; e.g. the upper half of FAT channel 1 is channel 5,
+ * and the overall FAT channel width centers on channel 3.
+ *
+ * NOTE:  The RXON command uses 20 MHz channel numbers to specify the
+ *        control channel to which to tune.  RXON also specifies whether the
+ *        control channel is the upper or lower half of a FAT channel.
+ *
+ * NOTE:  4965 does not support FAT channels on 2.4 GHz.
+ */
 #define EEPROM_REGULATORY_BAND_24_FAT_CHANNELS (2*0xA0)	/* 14 bytes */
-	struct iwl4965_eeprom_channel band_24_channels[7];	/* abs.ofs: 320 */
+	struct iwl4965_eeprom_channel band_24_channels[7]; /* abs.ofs: 320 */
 	u8 reserved11[2];
+
+/*
+ * 5.2 GHz FAT channels 36 (40), 44 (48), 52 (56), 60 (64),
+ * 100 (104), 108 (112), 116 (120), 124 (128), 132 (136), 149 (153), 157 (161)
+ */
 #define EEPROM_REGULATORY_BAND_52_FAT_CHANNELS (2*0xA8)	/* 22 bytes */
-	struct iwl4965_eeprom_channel band_52_channels[11];	/* abs.ofs: 336 */
+	struct iwl4965_eeprom_channel band_52_channels[11]; /* abs.ofs: 336 */
 	u8 reserved12[6];
+
+/*
+ * 4965 driver requires txpower calibration format version 5 or greater.
+ * Driver does not work with txpower calibration version < 5.
+ * This value is simply a 16-bit number, no major/minor versions here.
+ */
 #define EEPROM_CALIB_VERSION_OFFSET            (2*0xB6)	/* 2 bytes */
 	u16 calib_version;	/* abs.ofs: 364 */
 	u8 reserved13[2];
+
 #define EEPROM_SATURATION_POWER_OFFSET         (2*0xB8)	/* 2 bytes */
 	u16 satruation_power;	/* abs.ofs: 368 */
 	u8 reserved14[94];
+
+/*
+ * 4965 Txpower calibration data.
+ */
 #define EEPROM_IWL_CALIB_TXPOWER_OFFSET        (2*0xE8)	/* 48  bytes */
 	struct iwl4965_eeprom_calib_info calib_info;	/* abs.ofs: 464 */
 
@@ -317,6 +479,7 @@ struct iwl4965_eeprom {
 
 #define IWL_EEPROM_IMAGE_SIZE 1024
 
+/* End of EEPROM */
 
 #include "iwl-4965-commands.h"
 
diff --git a/drivers/net/wireless/iwlwifi/iwl-4965.c b/drivers/net/wireless/iwlwifi/iwl-4965.c
index e4930a5..fc7e6b6 100644
--- a/drivers/net/wireless/iwlwifi/iwl-4965.c
+++ b/drivers/net/wireless/iwlwifi/iwl-4965.c
@@ -4717,14 +4717,23 @@ struct pci_device_id iwl4965_hw_card_ids[] = {
 	{0}
 };
 
+/*
+ * The device's EEPROM semaphore prevents conflicts between driver and uCode
+ * when accessing the EEPROM; each access is a series of pulses to/from the
+ * EEPROM chip, not a single event, so even reads could conflict if they
+ * weren't arbitrated by the semaphore.
+ */
 int iwl4965_eeprom_acquire_semaphore(struct iwl4965_priv *priv)
 {
 	u16 count;
 	int rc;
 
 	for (count = 0; count < EEPROM_SEM_RETRY_LIMIT; count++) {
+		/* Request semaphore */
 		iwl4965_set_bit(priv, CSR_HW_IF_CONFIG_REG,
 			CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM);
+
+		/* See if we got it */
 		rc = iwl4965_poll_bit(priv, CSR_HW_IF_CONFIG_REG,
 					CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM,
 					CSR_HW_IF_CONFIG_REG_BIT_EEPROM_OWN_SEM,
-- 
1.5.2.2
---------------------------------------------------------------------
Intel Israel (74) Limited

This e-mail and any attachments may contain confidential material for
the sole use of the intended recipient(s). Any review or distribution
by others is strictly prohibited. If you are not the intended
recipient, please contact the sender and delete all copies.
-
To unsubscribe from this list: send the line "unsubscribe linux-wireless" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Linux Host AP]     [ATH6KL]     [Linux Bluetooth]     [Linux Netdev]     [Kernel Newbies]     [Linux Kernel]     [IDE]     [Security]     [Git]     [Netfilter]     [Bugtraq]     [Yosemite News]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux ATA RAID]     [Samba]     [Device Mapper]
  Powered by Linux