Re: GPMC in device tree

On Thu, Aug 6, 2015 at 6:07 AM, Scott Wood [off-list ref] wrote:

On Wed, 2015-08-05 at 17:27 +0300, Ran Shalit wrote:

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On Wed, Aug 5, 2015 at 9:11 AM, Ran Shalit [off-list ref] wrote:

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On Wed, Aug 5, 2015 at 6:56 AM, Ran Shalit [off-list ref] wrote:

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On Wed, Aug 5, 2015 at 12:25 AM, Scott Wood [off-list ref]
wrote:

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On Wed, 2015-08-05 at 00:22 +0300, Ran Shalit wrote:

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On more thing, if I may.
The localbus is also connected to nvram & cpld.
I've noticed that read/write works well, even though I didn't define
anything in device tree.
Is there any reasom to add these devices into device tree, or can we
use the cpld and nvram without the definition in device tree ?

I don't know what you're doing in your kernel to access devices that
aren't
in the device tree.  You should add the devices to the device tree,
and have
the kernel use it rather than hardcoded info.

-Scott

Hi,

Yes I understand.
But It is worse noting that I have no localbus entry in the device tree.
Yes, The nvram, cpld which are both connected to device tree, seems to
work without any issues.

Thanks,
Ran

I apologyze for the bad english, I meant "it worth to note" that there
is no localbus entry at all in the device tree.
So I wander how the nvram and cpld worked...

I don't know how it worked -- presumably there's something in your kernel
that hardcodes knowledge of those devices.

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If I may please ask, what should be the "compatible" for generic
devices such as  nvram/cpld ?

CPLD is not a generic device.  The compatible should describe the logic that
has been programmed into the CPLD.

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I assume that if they worked without any entry, it means that there is
no need for specific driver.

Regards,
Ran

Hi,

After studing the localbus configuration as should be configured in
device tree for powerpc, I think I have come with the following
configuration, (not yet tested on board):


 localbus@e0005000{
#address-cells = <2>;
#size-cells = <1>;
    compatible = "fsl,mpc8349-localbus", "simple-bus";
     reg = <0xe0005000 0x1000>;
     interrupts = <77 0x8>;
     interrupt-parent = <&ipic>;


/* NOR and NAND Flashes */
   ranges = <0x0 0x0 0xff800000 0x00800000         /* 8MB NOR Flash */
             0x1 0x0 0xF8000000 0x08000000      /* User flash (same
nor, in burst mode) 128M */
             0x2 0x0 0xf7e00000 0x00200000>;    /*NVRAM/CPLD C2 is
selected in CPLD , */
/*nvram 0xf7e00000 1MB */
/*cpld      0xf7f00000 1M  (<- different address!)*/
nor@0,0 {
#address-cells = <1>;
#size-cells = <1>;
compatible = "cfi-flash";
reg = <0x0 0x0 0x1000000>;
#bank-width = <1>;
device-width = <4>;

};
};

Hi ,

I reboot the board, with the new device tree localbus, but I don't
have any new /dev/mtdX entry for the NOR flash.
There is no HW issue, becuase we can R/W access the NOR flash from u-boot.
Is there any hint what can be the issue here ? I've checked in kernel
config and validated that mtd is supported.
The NOR flash is S29GL512P , SPANSION.

localbus@e0005000 {
#address-cells = <2>;
#size-cells = <1>;
   compatible = "fsl,mpc8349-localbus", "simple-bus";
    reg = <0xe0005000 0x1000>;
    interrupts = <77 0x8>;
    interrupt-parent = <&ipic>;


# NOR and NAND Flashes
  ranges = <0x0 0x0 0xff800000 0x00800000
    0x1 0x0 0xF8000000 0x08000000
    0x2 0x0 0xf7e00000 0x00200000>;
nor@0,0 {
#address-cells = <1>;
#size-cells = <1>;
compatible = "cfi-flash";
reg = <0x0 0x0 0x00800000>;
#bank-width = <1>;
device-width = <1>;

};
};

Best Regards,
Ran