Hi
Sorry the delay. Answers below.
On 03/16/2016 01:12 AM, sergk sergk2mail wrote:
Hi,
regarding "80860F41:03"
from DSDT 80860F41:
Name (_HID, "80860F41" /* Intel Baytrail I2C Host Controller */) //
_HID: Hardware ID
Name (_CID, "80860F41" /* Intel Baytrail I2C Host
Controller */) // _CID: Compatible ID
So, is this mean i2c-3?
It's third i2c-designware compatible I2C host controller but it doesn't
necessarily map into i2c-3. For instance if there are other I2C host
controller drivers like SMBUS or those in display controller initialized
before it.
ls -l /sys/bus/acpi/devices/CHPN0001:00
lrwxrwxrwx 1 root root 0 Mar 15 22:08
/sys/bus/acpi/devices/CHPN0001:00 ->
../../../devices/LNXSYSTM:00/LNXSYBUS:00/80860F41:03/CHPN0001:00
root@archiso ~ # cat /sys/bus/acpi/devices/CHPN0001:00/status
0
status is 0 - what does this mean? It is detected via ACPI but not present?
What does "LNXSYBUS:00/80860F41:03" means? Does it mean i2c-3, 0x41
? 80860F41:03 == ?
Path shows the complete device hierarchy where CHPN0001:00 is under
80860F41:03 bus but not present. Looking at the DSDT snippet you posted
into thread there is _STA method that forms the above status:
Method (_STA, 0, NotSerialized) // _STA: Status
{
If ((OSSL & 0x80))
{
Return (Zero)
}
If ((OSYS == 0x07DD))
{
Return (0x0F)
}
Else
{
Return (0x0F)
}
}
I don't know what these OSSL and OSYS variables are. I guess OSSL
represents either some BIOS configuration or alternative device
manufacturer can use. Is there other similar device defined under
80860F41:03 that could be present (status == 15)?
The _DSM method shows it indeeds is an i2c-hid device and no new driver
is required:
Method (_DSM, 4, Serialized) // _DSM: Device-Specific
Method
{
Name (_T_1, Zero) // _T_x: Emitted by ASL Compiler
Name (_T_0, Zero) // _T_x: Emitted by ASL Compiler
Debug = "Method _DSM begin"
If ((Arg0 == ToUUID
("3cdff6f7-4267-4555-ad05-b30a3d8938de") /* HID I2C Device */))
This same UUID is matched in drivers/hid/i2c-hid/i2c-hid.c:
i2c_hid_acpi_pdata().
So the question is the same - how to obtain via acpi in mentioned
above code i2cbus, bus addr and irq for this touch?
Look up happens in acpi_i2c_add_device() and acpi_i2c_find_address() in
drivers/i2c/i2c-core.c but device must be present.
--
Jarkko
--
To unsubscribe from this list: send the line "unsubscribe linux-i2c" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
