> Le 25/06/2010 22:08, Steve Brown a écrit :
>>
>> I see that there are some TO DO comments in the ath5k code for
>> half/quarter channels. Is this being worked on?
>>
>> If not and somebody on the list has the needed info and would be willing
>> to suffer some dumb questions, I'll try to add it.
>>
>> Steve
>
> Hi Steve,
>
> Reading ath5k, I gathered the following information :
>
> /*
> * PHY timing register 3 [5112+]
> */
> #define AR5K_PHY_TIMING_3 0x9814
> #define AR5K_PHY_TIMING_3_DSC_MAN 0xfffe0000
> #define AR5K_PHY_TIMING_3_DSC_MAN_S 17
> #define AR5K_PHY_TIMING_3_DSC_EXP 0x0001e000
> #define AR5K_PHY_TIMING_3_DSC_EXP_S 13
>
> This describe the mantissa (MAN) and exponent (EXP) of the clock used
> to compute the center frequency. This value is divided by 2 for 10 MHz
> channels.
>
> /*
> * PHY PLL (Phase Locked Loop) control register
> */
> #define AR5K_PHY_PLL 0x987c
> #define AR5K_PHY_PLL_HALF_RATE 0x00000100
> #define AR5K_PHY_PLL_QUARTER_RATE 0x00000200
>
> For 802.11a (40MHz PLL), bit AR5K_PHY_PLL_HALF is set to get 10 MHz
> channels. That's probably the most important register.
>
> /*
> * PHY mode register [5111+]
> */
> #define AR5K_PHY_MODE 0x0a200 /*
> Register Address */
> #define AR5K_PHY_MODE_MOD 0x00000001 /* PHY
> Modulation bit */
> #define AR5K_PHY_MODE_MOD_OFDM 0
> #define AR5K_PHY_MODE_MOD_CCK 1
> #define AR5K_PHY_MODE_FREQ 0x00000002 /* Freq mode
> bit */
> #define AR5K_PHY_MODE_FREQ_5GHZ 0
> #define AR5K_PHY_MODE_FREQ_2GHZ 2
> #define AR5K_PHY_MODE_MOD_DYN 0x00000004 /* Enable
> Dynamic OFDM/CCK mode [5112+] */
> #define AR5K_PHY_MODE_RAD 0x00000008 /* [5212+] */
> #define AR5K_PHY_MODE_RAD_RF5111 0
> #define AR5K_PHY_MODE_RAD_RF5112 8
> #define AR5K_PHY_MODE_XR 0x00000010 /* Enable XR
> mode [5112+] */
> #define AR5K_PHY_MODE_HALF_RATE 0x00000020 /* Enable Half
> rate (test) */
> #define AR5K_PHY_MODE_QUARTER_RATE 0x00000040 /* Enable
> Quarter rat (test) */
>
> For 10 MHz channels, AR5K_PHY_MODE_HALF_RATE needs to be set.
>
> There are also some information on madwifi-free :
>
http://madwifi-project.org/browser/madwifi/trunk/ath_hal/ar5212/ar5212_reset.c
>
>
> I've not played myself with those bits, but that could be a good
> starting point for you.
>
> Regards,
> Benoit
