On 3/30/20 8:46 AM, Michal Simek wrote:
> On 30. 03. 20 17:24, Guenter Roeck wrote:
>> On 3/30/20 4:33 AM, Michal Simek wrote:
>>> Hi Robert and Guenter,
>>>
>>> Xilinx boards are using IRPS5401 chips and I have tried to use your driver.
>>> I have checked that u-boot can detect that devices and read it.
>>>
>>> ZynqMP> i2c probe
>>> Valid chip addresses: 0C 13 14 20 43 44 74
>>> ZynqMP> i2c md 13 0 10
>>> 0000: 00 08 00 08 00 08 00 08 00 08 00 08 00 08 00 08 ................
>>> ZynqMP> i2c md 14 0 10
>>> 0000: 00 08 00 08 00 08 00 08 00 08 00 08 00 08 00 08 ................
>>> ZynqMP> i2c md 43 0 10
>>> 0000: 00 98 ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
>>> ZynqMP> i2c md 44 0 10
>>> 0000: 00 8a ff ff ff ff ff ff ff ff ff ff ff ff ff ff ................
>>> ZynqMP>
>>>
>>> Here is DT fragment which I use (it is under i2c mux)
>>>
>>> 185 irps5401_43: irps5401@43 {
>>> 186 compatible = "infineon,irps5401";
>>> 187 reg = <0x43>; /* pmbus / i2c 0x13 */
>>
>> Does that mean the mux is at 0x13 ?
>
> HW guys wrote that 0x13 is i2c address and 0x43 is pmbus address.
>
Sorry, I have no idea what that is supposed to mean. PMBus is SMBus
which, for all practical purpose, is i2c. There is no difference between
PMBus and I2C addresses.
[ ... ]
>
> There is nothing else on schematics. When I try 0x13/0x14 I am getting.
> irps5401 3-0013: Failed to identify chip capabilities
> irps5401 3-0014: Failed to identify chip capabilities
>
Yes, the chips at those addresses don't look like PMBus chips.
Maybe the chips are on other i2c busses. There must be at least four
of them in the system.
>>> Also I would like to know if there is a way to disable it via any API.
>>
>> Not sure what you want to disable. The message ? The PMBus core needs
>> to have access to the chip to initialize. If there is no status register,
>> there is nothing it can do but to refuse to instantiate.
>
> When driver is probed I would like to be able from user space
> enable/disable the specific output from PMIC. This one has 4 VOUTs.
>
You mean to instantiate a regulator ? That is possible; see
drivers/hwmon/pmbus/ltc2978.c for an example. I don't know if one
can enable/disable regulators from userspace, though.
Guenter
