[Intel-gfx] [PATCH v6 3/4] ACPI / PMIC: Add generic intel_soc_pmic_exec_mipi_pmic_seq_element handling

[Hans de Goede]

Hi,

On 07-01-19 16:46, Andy Shevchenko wrote:
> On Mon, Jan 07, 2019 at 12:15:55PM +0100, Hans de Goede wrote:
>> Most PMIC-s use only a single i2c-address, so after verifying the
>> i2c-address matches, we can simply pass the call to regmap_update_bits.
>>
>> This commit adds support for this and hooks this up for the xpower AXP288
>> PMIC by setting the new pmic_i2c_address field.
>>
>> This fixes the following errors on display on / off on a Jumper Ezpad
>> mini 3 and an Onda V80 plus tablet, both of which use the AXP288:
>>
>> intel_soc_pmic_exec_mipi_pmic_seq_element: Not implemented
>> intel_soc_pmic_exec_mipi_pmic_seq_element: i2c-addr: 0x34 reg-addr ...
>> [drm:mipi_exec_pmic [i915]] *ERROR* mipi_exec_pmic failed, error: -95
>>
>> Instead of these errors on both devices we now correctly turn on / off
>> DLDO3 (through direct register manipulation). On the Onda V80 plus this
>> fixes an issue with the backlight being brighter around the borders after
>> an off / on cycle. This should also help to save some power when the
>> display is off.
> 
>> +	} else if (d->pmic_i2c_address) {
>> +		if (i2c_address == d->pmic_i2c_address) {
>> +			ret = regmap_update_bits(intel_pmic_opregion->regmap,
>> +						 reg_address, mask, value);
>> +		} else {
>> +			pr_err("%s: Unexpected i2c-addr: 0x%02x (reg-addr 0x%x value 0x%x mask 0x%x)\n",
>> +			       __func__, i2c_address, reg_address, value, mask);
>> +			ret = -ENXIO;
>> +		}
> 
>> --- a/drivers/acpi/pmic/intel_pmic_xpower.c
>> +++ b/drivers/acpi/pmic/intel_pmic_xpower.c
>> +	.pmic_i2c_address = 0x34,
> 
> Can we just have a hook here instead of exposing PMIC I2C address?
> Am I missing something in case it's not possible?

We already have a hook, but it isn't really necessary to implement
that for each model PMIC. The MFD device which is the PMIC's parent
in most cases will give us a regmap to access the PMIC registers and
that allows us to do a generic implementation.

But the MIPI PMIC sequence includes an i2c-address as some PMICs
span multiple i2c-addresses. For the simple single i2c-address case
the regmap gives us access to the registers behind that single address
and we can use a generic solution. In this case we should verify the
i2c-addr is what we expect, which is where the pmic_i2c_address comes in.

Regards,

Hans