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Wi-Fi Bluetooth for Linux

ChSi_4659482
New Contributor

Hello ZhengbaoZ_96,

We are working on integrating CYW43438 based module with a AM335x based board.

When we attached the module over SDIO, it is not detected at all.

Could it be due to the processor stopping the clock after CMD0?

Is there any workaround?

Thanks in advance!

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1 Solution
GauravS_31
Moderator
Moderator

Thanks for the information. From the dmesg logs, I do not see the chip getting enumerated. From your oscilloscope, do you see WL_REG_ON high and stable during the bring-up? Which version of FMAC is being used here? Did you use the following commands to bring up the driver?

insmod compat.ko

insmod cfg80211.ko

insmod brcmutil.ko

insmod brcmfmac.ko

Secondly, the WLAN firmware is dated back to 2017 and i do not see clm_blob file in the directory. Our recommendation is to use the latest firmware which contains security fixes to known Wi-Fi vulnerabilities. Since the latest firmware requires clm_blob support, the FMAC driver would also need to be upgraded to the latest version.

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7 Replies
GauravS_31
Moderator
Moderator

Which driver is being used? Which commands have you used for WLAN bringup? Can you share the dmesg logs? Regarding your question on CMD0, do you observe from oscilloscope that the SDIO clock stops during WLAN bringup?

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ChSi_4659482
New Contributor

Thanks Gaurav for your response.

System is powered on with the module plugged in over SDIO but no detection takes place. Yes we can see that the SDIO clock stops.

Please find the attached following: Drivers, dmesg logs, device tree.

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GauravS_31
Moderator
Moderator

Thanks for the information. From the dmesg logs, I do not see the chip getting enumerated. From your oscilloscope, do you see WL_REG_ON high and stable during the bring-up? Which version of FMAC is being used here? Did you use the following commands to bring up the driver?

insmod compat.ko

insmod cfg80211.ko

insmod brcmutil.ko

insmod brcmfmac.ko

Secondly, the WLAN firmware is dated back to 2017 and i do not see clm_blob file in the directory. Our recommendation is to use the latest firmware which contains security fixes to known Wi-Fi vulnerabilities. Since the latest firmware requires clm_blob support, the FMAC driver would also need to be upgraded to the latest version.

View solution in original post

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ChSi_4659482
New Contributor

Is the device tree alright?

How to get the FMAC driver? Shall I use this one  Cypress Linux WiFi Driver Release (FMAC) [2020-04-02] ?

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GauravS_31
Moderator
Moderator

The latest FMAC driver is available here Cypress Linux WiFi Driver Release (FMAC) [2020-06-25]

The device tree is under evaluation. I will share the feedback early next week.

ChSi_4659482
New Contributor

Thanks Gaurav, looking forward to it

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GauravS_31
Moderator
Moderator

I have some questions based on the device tree as well as some general questions on the hardware:

1. The clock frequency has been specified 38400000. Shouldn't it be 37.4MHz?

2. What is the pull-up resistor value on the SDIO lines? As per the datasheet, it should lie in the range of 10k to 100k ohms on the 4 data lines and CMD line. What is the difference between MUX_MODE1 and MUX_MODE2?

3. For WL_REG_ON, a minimum 10ms delay should be provided between consecutive toggles as per the datasheet. Is the startup-delay-us taking care of this?

4. Why is compatible specified as "brcm,bcm4329-fmac"?

5. Do you have a common power supply for both host and radio?

6. Was the hardware schematic and layout reviewed by the module vendor? Did you obtain nvram from module vendor?