Hi Michal,
On Tue, Jan 3, 2017 at 1:22 AM, Michal Simek <michal.si...@xilinx.com> wrote:
> On 2.1.2017 20:20, Moritz Fischer wrote:
>> Hi Michal,
>>
>> On Mon, Jan 2, 2017 at 6:24 AM, Michal Simek <michal.si...@xilinx.com> wrote:
>>> On 29.12.2016 23:50, Moritz Fischer wrote:
>>>> For mux check if the parent is already a device of UCLASS_I2C and if yes
>>>> just use that. Otherwise see if someone specified an i2c-parent phandle.
>>>> This mimics the behavior found in the Kernel, as it removes the
>>>> requirement to explicitly specify a i2c-parent phandle.
>>>>
>>>> Signed-off-by: Moritz Fischer <moritz.fisc...@ettus.com>
>>>> Cc: Heiko Schocher <h...@denx.de>
>>>> Cc: Bin Meng <bmeng...@gmail.com>
>>>> Cc: Simon Glass <s...@chromium.org>
>>>> Cc: Michal Simek <michal.si...@xilinx.com>
>>>> Cc: u-boot@lists.denx.de
>>>> ---
>>>> drivers/i2c/muxes/i2c-mux-uclass.c | 9 +++++++++
>>>> 1 file changed, 9 insertions(+)
>>>>
>>>> diff --git a/drivers/i2c/muxes/i2c-mux-uclass.c
>>>> b/drivers/i2c/muxes/i2c-mux-uclass.c
>>>> index 7a698b6..e01b773 100644
>>>> --- a/drivers/i2c/muxes/i2c-mux-uclass.c
>>>> +++ b/drivers/i2c/muxes/i2c-mux-uclass.c
>>>> @@ -86,6 +86,15 @@ static int i2c_mux_post_probe(struct udevice *mux)
>>>> debug("%s: %s\n", __func__, mux->name);
>>>> priv->selected = -1;
>>>>
>>>> + /* if parent is of i2c uclass already, we'll take that, otherwise
>>>> + * look if we find an i2c-parent phandle */
>>>
>>> Incorrect comment style.
>>
>> Yeah, wasn't flagged by checkpatch .... will fix.
>>>
>>>> + if (UCLASS_I2C == device_get_uclass_id(mux->parent)) {
>>>> + priv->i2c_bus = dev_get_parent(mux);
>>>> + debug("%s: bus=%p/%s\n", __func__, priv->i2c_bus,
>>>> + priv->i2c_bus->name);
>>>> + return 0;
>>>> + }
>>>> +
>>>> ret = uclass_get_device_by_phandle(UCLASS_I2C, mux, "i2c-parent",
>>>> &priv->i2c_bus);
>>>> if (ret)
>>>>
>>>
>>> The part of this will be good to also handle
>>> req_seq for mux busses. But at least this should solved part of the
>>> problems.
>>
>> I'm not sure I understand this comment.
>
> AFAIK using i2c muxes requires two changes in DTS file.
> First change is this to setup i2c-parent in DTS file which is something
> what Linux doesn't need.
Yeah this part is addressed in this patch.
> The next change is that you have to extend i2c aliases to point to i2c
> mux sub busses which is the second thing what Linux doesn't need.
> I expect that this change you have in your dts file.
Yeah, thanks for clarifying. In my dts I have aliases for each of the
mux channels,
which, I don't have a good idea on how to solve differently. In Linux
I think I don't need that.
> I think that if you detect mux with 8 ports you can simply use unique
> busid to be able to address them.
In Linux? I'll have to take another look at that. Currently I get
busses like 700,701,702 etc (which are aliases I defined).
Each of them points to a mux channel.
<snip>
aliases { ...
i2c0 = &i2c0;
i2c0700 = &i2c0_70_0;
i2c0701 = &i2c0_70_1;
i2c0702 = &i2c0_70_2;
i2c0703 = &i2c0_70_3;
};
...
i2cswitch@70 {
compatible = "ti,pca9548", "nxp,pca9548";
#address-cells = <1>;
#size-cells = <0>;
reg = <0x70>;
status = "okay";
i2c0_70_0: i2c@0 {
reg = <0x0>;
#address-cells = <1>;
#size-cells = <0>;
status = "okay";
};
...
};
</snip>
I Will resubmit a v2 for the other changes above
If you or Simon have ideas on how to correctly solve the alias issue,
I can take another stab at that.
Thanks,
Moritz
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