[U-Boot] [PATCH] dm: gpio: pca953x: introduce driver model support for pca953x

[Michal Simek]

On 13.4.2016 07:50, Peng Fan wrote:
> Hi Michal,
> On Tue, Apr 12, 2016 at 07:17:55AM +0200, Michal Simek wrote:
>> On 12.4.2016 03:25, Peng Fan wrote:
>>> Hi Michal,
>>>
>>> On Mon, Apr 11, 2016 at 02:40:06PM +0200, Michal Simek wrote:
>>>> On 11.4.2016 14:09, Michal Simek wrote:
>>>>> On 11.4.2016 07:47, Peng Fan wrote:
>>>>>> On Sat, Apr 09, 2016 at 12:33:34PM -0600, Simon Glass wrote:
>>>>>>> On 18 March 2016 at 03:54, Peng Fan <van.freenix at gmail.com> wrote:
>>>>>>>> Introduce a new driver that supports driver model for pca953x.
>>>>>>>> The pca953x chips are used as I2C I/O expanders.
>>>>>>>> This driver is designed to support the following chips:
>>>>>>>> "
>>>>>>>> 4 bits: pca9536, pca9537
>>>>>>>> 8 bits: max7310, max7315, pca6107, pca9534, pca9538, pca9554,
>>>>>>>>         pca9556, pca9557, pca9574, tca6408, xra1202
>>>>>>>> 16 bits: max7312, max7313, pca9535, pca9539, pca9555, pca9575,
>>>>>>>>          tca6416
>>>>>>>> 24 bits: tca6424
>>>>>>>> 40 bits: pca9505, pca9698
>>>>>>>> "
>>>>>>>> But for now this driver only supports max 24 bits and pca953x compatible
>>>>>>>> chips. pca957x compatible chips are not supported now.
>>>>>>>> These can be addressed when we need to add such support for the different
>>>>>>>> chips.
>>>>>>>> This driver has been tested on i.MX6 SoloX Sabreauto board with max7310
>>>>>>>> i2c expander using gpio command as following:
>>>>>>>>
>>>>>>>> =>gpio status -a
>>>>>>>> Bank gpio at 48:
>>>>>>>> gpio at 480: input: 1 [ ]
>>>>>>>> => gpio clear gpio at 480
>>>>>>>> gpio: pin gpio at 480 (gpio 224) value is 0
>>>>>>>> => gpio status -a
>>>>>>>> Bank gpio at 48:
>>>>>>>> gpio at 480: output: 0 [ ]
>>>>>>>
>>>>>>> Don't you think 480 is confusing? Perhaps you should have gpio at 48_ as
>>>>>>> the bank name? Also I think you should support a gpio-bank-name
>>>>>>> property in the node, to allow a sensible name to be provided.
>>>>>>
>>>>>> 480 is added by gpio uclass driver I think.
>>>>>> The dts is copied from Linux side. I'd not change the dts, will try to
>>>>>> see how to introudce a sensible name here.
>>>>>
>>>>> What's the binding you are using?
>>>>>
>>>>> The part of this patch should be DT binding.
>>>>>
>>>>> This is my node.
>>>>> 	tca6416_u61: gpio at 21 {
>>>>> 		compatible = "ti,tca6416";
>>>>> 		reg = <0x21>;
>>>>> 		gpio-controller;
>>>>> 		#gpio-cells = <2>;
>>>>> 	};
>>>>>
>>>>
>>>> Ok. I found where the problem is.
>>>>
>>>> i2c bus has
>>>> #address-cells = <1>;
>>>> #size-cells = <0>;
>>>>
>>>> And then OF_CHECK_COUNTS thinks that it is incorrect setting for bus
>>>> but it should be valid for i2c where only address without size is used.
>>>> When I apply patch below driver is probed
>>>
>>> I did not met this issue.
>>
>> That's interesting. Can you please add
>>
>> Can you please apply this and look at na and ns values?
>> If you are on imx6q then you should reach the same problem as I if this
>> code is called that's why I would like to confirm this.
>>
>> diff --git a/common/fdt_support.c b/common/fdt_support.c
>> index ced119e70d9f..9c18b312d647 100644
>> --- a/common/fdt_support.c
>> +++ b/common/fdt_support.c
>> @@ -1109,6 +1109,7 @@ static u64 __of_translate_address(void *blob, int
>> node_offset, const fdt32_t *in
>>
>>        /* Cound address cells & copy address locally */
>>        bus->count_cells(blob, parent, &na, &ns);
>> +       printf("addr cells %d, size cells %d\n", na, ns);
>>        if (!OF_CHECK_COUNTS(na, ns)) {
>>                printf("%s: Bad cell count for %s\n", __FUNCTION__,
>>                       fdt_get_name(blob, node_offset, NULL));
>>
>>
>>>
>>>>
>>>>
>>>> diff --git a/common/fdt_support.c b/common/fdt_support.c
>>>> index ced119e70d9f..5f5b49c6210b 100644
>>>> --- a/common/fdt_support.c
>>>> +++ b/common/fdt_support.c
>>>> @@ -941,7 +941,7 @@ void fdt_del_node_and_alias(void *blob, const char
>>>> *alias)
>>>> #define OF_MAX_ADDR_CELLS      4
>>>> #define OF_BAD_ADDR    FDT_ADDR_T_NONE
>>>> #define OF_CHECK_COUNTS(na, ns)        ((na) > 0 && (na) <=
>>>> OF_MAX_ADDR_CELLS && \
>>>> -                       (ns) > 0)
>>>> +                       (ns) >= 0)
> 
> You are correct.
> 
> I have no idea why I first test my patch, I did not met the issue as you.
> After applying your patch as above, gpio status -a can correctly detect
> max7310.
> 
> The dts I used is for mx6sxsabreauto board, not in U-Boot now.

good. Do you want me to create this patch or do you want to create it
and add it as 1/2 before this one?

Thanks,
Michal