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by lioryb
Mon Jul 30, 2018 10:56 am
Forum: Device Tree
Topic: GPIO - SMI pulldown
Replies: 3
Views: 1487

Re: GPIO - SMI pulldown

Thanks both for your replies. Burngate Indeed, it's ALT1 not ALT2 (my typo). Yet, the pins are actually pulled up. These are so called address pins, in smi-nand driver are used as controls (NAND uses address and data multiplexed). PhilE I am not sure I understand your remark. in the DTS file, I chan...
by lioryb
Sun Jul 29, 2018 2:52 pm
Forum: Device Tree
Topic: GPIO - SMI pulldown
Replies: 3
Views: 1487

GPIO - SMI pulldown

Hi.

While trying to work with with GPIO in SMI mode (ALT2 mode), I want on of SA0-SA5 to be pulled down.
I tried to config these pins as pulled down, but they keep being pulled up (using Logic Analyzer).

Is there any restrictions on ALT2 mode to deny pulldown on GPIO-GPIO5?

Thanks
by lioryb
Thu Jul 19, 2018 7:28 am
Forum: Device Tree
Topic: Connecting external raw nand using GPIO - RPI3b
Replies: 16
Views: 8405

Re: Connecting external raw nand using GPIO - RPI3b

Thank you Luke for you reply. So, I understand SA0-SA5 are actually used for all the NAND controls? where can I find the CE and R_B conrols? I am experiencing a few more issues with the driver, and I would be thankful if you could help. when I add the SMI-NAND overlay, w Apparently, in bcm2835_smi_n...
by lioryb
Mon Jul 16, 2018 11:01 am
Forum: Device Tree
Topic: Connecting external raw nand using GPIO - RPI3b
Replies: 16
Views: 8405

Re: Connecting external raw nand using GPIO - RPI3b

I know that guide, but on ALT1, which is the relevant assignment for the SMI-NAND, GPIO-GPIO, are called SA5-SA0, while it should have CE, R/B ALE, CLE ext. I noticed, on the driver code, the following defines: #define SMI_NAND_CLE_PIN 0x01 #define SMI_NAND_ALE_PIN 0x02 and I wonder does these pins ...
by lioryb
Mon Jul 16, 2018 10:28 am
Forum: Device Tree
Topic: Connecting external raw nand using GPIO - RPI3b
Replies: 16
Views: 8405

Re: Connecting external raw nand using GPIO - RPI3b

Address and Data are multiplexed on NAND device, That is how NAND works. The main issue is that it should support both output and input.
Is there any 'thumb-rule' where I can find how to connect the RPI3 headers pin? How can I find each pins' connectivity, from the smi-nand driver?
by lioryb
Mon Jul 16, 2018 9:43 am
Forum: Device Tree
Topic: Connecting external raw nand using GPIO - RPI3b
Replies: 16
Views: 8405

Re: Connecting external raw nand using GPIO - RPI3b

Thanks again for your help. I did notice that there is that smi-nand ovleray and went through the thread you mentioned. Unfortunately, the thread hardly mentions the nand issue, so I couldn't find any help there. The only thing I could get from there, is that looks like I need to load both smi overl...
by lioryb
Sun Jul 15, 2018 8:20 am
Forum: Device Tree
Topic: Connecting external raw nand using GPIO - RPI3b
Replies: 16
Views: 8405

Re: Connecting external raw nand using GPIO - RPI3b

Thanks Phil for you reply.
Reading deeper into BCM2835 datasheet shows that some of the GPIO pins may be configured to Secondary Module Interface, and the example in "Documentation/devicetree/bindings/misc/brcm,bcm2835-smi.txt" specifically mentions the use for NAND.
Wouldn't that answer my issue?
by lioryb
Thu Jul 12, 2018 12:10 pm
Forum: Device Tree
Topic: Connecting external raw nand using GPIO - RPI3b
Replies: 16
Views: 8405

Connecting external raw nand using GPIO - RPI3b

Hi. I'm trying to define a device tree for connecting an external raw NAND using GPIO on RPI3. I found that there are available drivers, and I found an example in the sources' "Documentation" directory (Documentation/devicetree/bindings/mtd/gpio-control-nand.txt) Yet, while using this example, I cou...

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