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

[Michal Simek <michal.simek@xilinx.com>]

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@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


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)

 /* Debug utility */
 #ifdef DEBUG

Regarding numbers. It is just hex to int conversion + gpio number.
It means gpio at 20 is 0x20 which is 32. Using hex everywhere make sense
and this is the fix. Maybe better to also use underscore.

diff --git a/drivers/gpio/pca953x_gpio.c b/drivers/gpio/pca953x_gpio.c
index 6b67b079a17b..1eeb4c8f199a 100644
--- a/drivers/gpio/pca953x_gpio.c
+++ b/drivers/gpio/pca953x_gpio.c
@@ -292,7 +292,7 @@ static int pca953x_probe(struct udevice *dev)
                return ret;
        }

-       snprintf(name, sizeof(name), "gpio@%u", info->addr);
+       snprintf(name, sizeof(name), "gpio@%x_", info->addr);
        str = strdup(name);
        if (!str)
                return -ENOMEM;

Output below.

Thanks,
Michal

ZynqMP> dm tree
 Class       Probed   Name
----------------------------------------
 root        [ + ]    root_driver
 simple_bus  [   ]    |-- amba_apu
 simple_bus  [ + ]    `-- amba
 eth         [ + ]        |-- ethernet at ff0e0000
 i2c         [ + ]        |-- i2c at ff020000
 gpio        [ + ]        |   |-- gpio at 20
 gpio        [ + ]        |   |-- gpio at 21
 i2c_mux     [   ]        |   `-- i2cswitch at 75
 i2c         [   ]        |       |-- i2c at 0
 i2c         [   ]        |       |-- i2c at 1
 i2c         [   ]        |       `-- i2c at 2
 i2c         [   ]        |-- i2c at ff030000
 i2c_mux     [   ]        |   |-- i2cswitch at 74
 i2c         [   ]        |   |   |-- i2c at 0
 i2c         [   ]        |   |   |-- i2c at 1
 i2c         [   ]        |   |   |-- i2c at 2
 i2c         [   ]        |   |   |-- i2c at 3
 i2c         [   ]        |   |   `-- i2c at 4
 i2c_mux     [   ]        |   `-- i2cswitch at 75
 i2c         [   ]        |       |-- i2c at 0
 i2c         [   ]        |       |-- i2c at 1
 i2c         [   ]        |       |-- i2c at 2
 i2c         [   ]        |       |-- i2c at 3
 i2c         [   ]        |       |-- i2c at 4
 i2c         [   ]        |       |-- i2c at 5
 i2c         [   ]        |       |-- i2c at 6
 i2c         [   ]        |       `-- i2c at 7
 mmc         [ + ]        |-- sdhci at ff170000
 serial      [ + ]        |-- serial at ff000000
 serial      [   ]        `-- serial at ff010000
ZynqMP> i2c bus
Bus 0:	i2c at ff020000  (active 0)
   20: gpio at 20, offset len 1, flags 0
   21: gpio at 21, offset len 1, flags 0
   75: i2cswitch at 75, offset len 1, flags 0
Bus 750:	i2c at 0
Bus 751:	i2c at 1
Bus 752:	i2c at 2
Bus 1:	i2c at ff030000
   74: i2cswitch at 74, offset len 1, flags 0
   75: i2cswitch at 75, offset len 1, flags 0
Bus 750:	i2c at 0
Bus 751:	i2c at 1
Bus 752:	i2c at 2
Bus 1743:	i2c at 3
Bus 1744:	i2c at 4
Bus 750:	i2c at 0
Bus 751:	i2c at 1
Bus 752:	i2c at 2
Bus 1743:	i2c at 3
Bus 1744:	i2c at 4
Bus 1755:	i2c at 5
Bus 1756:	i2c at 6
Bus 1757:	i2c at 7
ZynqMP> gpio status -a
Bank gpio at 20_:
gpio at 20_0: output: 1 [ ]
gpio at 20_1: output: 1 [ ]
gpio at 20_2: output: 1 [ ]
gpio at 20_3: output: 1 [ ]
gpio at 20_4: output: 0 [ ]
gpio at 20_5: output: 1 [ ]
gpio at 20_6: output: 1 [ ]
gpio at 20_7: output: 1 [ ]
gpio at 20_8: output: 0 [ ]
gpio at 20_9: output: 0 [ ]
gpio at 20_10: output: 0 [ ]
gpio at 20_11: output: 0 [ ]
gpio at 20_12: output: 0 [ ]
gpio at 20_13: output: 0 [ ]
gpio at 20_14: output: 0 [ ]
gpio at 20_15: output: 0 [ ]

Bank gpio at 21_:
gpio at 21_0: input: 1 [ ]
gpio at 21_1: input: 1 [ ]
gpio at 21_2: input: 1 [ ]
gpio at 21_3: input: 1 [ ]
gpio at 21_4: input: 1 [ ]
gpio at 21_5: input: 0 [ ]
gpio at 21_6: input: 0 [ ]
gpio at 21_7: input: 0 [ ]
gpio at 21_8: input: 0 [ ]
gpio at 21_9: input: 0 [ ]
gpio at 21_10: input: 0 [ ]
gpio at 21_11: input: 0 [ ]
gpio at 21_12: input: 0 [ ]
gpio at 21_13: input: 0 [ ]
gpio at 21_14: input: 0 [ ]
gpio at 21_15: input: 0 [ ]
ZynqMP>