Commit Graph

10 Commits

Author SHA1 Message Date
Andy Shevchenko 0d5102fe85 i2c: acpi: Introduce i2c_acpi_get_i2c_resource() helper
Besides current two users one more is coming. Definitely makes sense to
introduce a helper.

No functional change intended.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-03 21:40:02 +02:00
Andy Shevchenko 5f59d6a110 i2c: acpi: Use ACPI_FAILURE instead of !ACPI_SUCCESS
Convert to use ACPI_FAILURE instead of !ACPI_SUCCESS.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-03 21:40:02 +02:00
Andy Shevchenko 2dea645ffc i2c: acpi: Return error pointers from i2c_acpi_new_device()
The caller would like to know the reason why the i2c_acpi_new_device() fails.
For example, if adapter is not available, it might be in the future and we
would like to re-probe the clients again. But at the same time we would like to
bail out if the error seems unrecoverable, such as invalid argument supplied.
To achieve this, return error pointer in some cases.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
2018-12-03 21:40:02 +02:00
Hans de Goede 0a30446c0d i2c: core: ACPI: Make acpi_gsb_i2c_read_bytes() check i2c_transfer return value
Currently acpi_gsb_i2c_read_bytes() directly returns i2c_transfer's return
value. i2c_transfer returns a value < 0 on error and 2 (for 2 successfully
executed transfers) on success. But the ACPI code expects 0 on success, so
currently acpi_gsb_i2c_read_bytes()'s caller does:

        if (status > 0)
                status = 0;

This commit makes acpi_gsb_i2c_read_bytes() return a value which can be
directly consumed by the ACPI code, mirroring acpi_gsb_i2c_write_bytes(),
this commit also makes acpi_gsb_i2c_read_bytes() explitcly check that
i2c_transfer returns 2, rather then accepting any value > 0.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-08-20 14:09:26 +02:00
Hans de Goede c463a158cb i2c: core: ACPI: Properly set status byte to 0 for multi-byte writes
acpi_gsb_i2c_write_bytes() returns i2c_transfer()'s return value, which
is the number of transfers executed on success, so 1.

The ACPI code expects us to store 0 in gsb->status for success, not 1.

Specifically this breaks the following code in the Thinkpad 8 DSDT:

            ECWR = I2CW = ECWR /* \_SB_.I2C1.BAT0.ECWR */
            If ((ECST == Zero))
            {
                ECRD = I2CR /* \_SB_.I2C1.I2CR */
            }

Before this commit we set ECST to 1, causing the read to never happen
breaking battery monitoring on the Thinkpad 8.

This commit makes acpi_gsb_i2c_write_bytes() return 0 when i2c_transfer()
returns 1, so the single write transfer completed successfully, and
makes it return -EIO on for other (unexpected) return values >= 0.

Cc: stable@vger.kernel.org
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-08-20 14:08:59 +02:00
Hans de Goede 7781edaed6 i2c: core: ACPI: Log device not acking errors at dbg loglevel
Unfortunately some DSDTs issue bogus i2c reads to non existing devices
resulting in -EREMOTEIO errors because the non existing device of course
does not ack.

This happens e.g. from the The Asus T100TA's _BIX method, the DSDT on
the T100TA defines 2 resources on the I2C1 bus:

        Name (EHID, ResourceTemplate ()
        {
            I2cSerialBusV2 (0x005B, ControllerInitiated, 0x00061A80,
                AddressingMode7Bit, "\\_SB.I2C1",
                0x00, ResourceConsumer, , Exclusive,
                )
        })
        OperationRegion (EHOR, GenericSerialBus, Zero, 0x0100)
        Field (EHOR, BufferAcc, NoLock, Preserve)
        {
            Connection (EHID),
            Offset (0x01),
            AccessAs (BufferAcc, AttribBytes (0x10)),
            ABCD,   8
        }

        Name (UMPC, ResourceTemplate ()
        {
            I2cSerialBusV2 (0x0066, ControllerInitiated, 0x00061A80,
                AddressingMode7Bit, "\\_SB.I2C1",
                0x00, ResourceConsumer, , Exclusive,
                )
        })

The _BIX method does a single read (on each BIX() call) from the EHID
device through the ABCD Field, only to completely ignore the result.
This read always fails as there is no i2c client at address 0x5b.

The _BIX method also does several reads from the UMPC device and actually
uses the results of those to provide battery information.

IIRC I've also seen some DSTDs which do an i2c read to detect if a device
is present, also leading to false positive errors being logged.

Esp. the _BIX use is problematic as the _BIX method gets called
periodically to monitor battery status.

This commit stops the logs from filling up with errors like these:

[   57.327858] i2c i2c-0: i2c read 16 bytes from client@0x5b starting at
               reg 0x1 failed, error: -121

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:53:31 +02:00
Hans de Goede c8016fa215 i2c: core: ACPI: Improve OpRegion read errors
When we get an error doing an ACPI SerialBus I2C OpRegion read log some
useful details, like the client address and which register is being
read.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2018-04-30 10:53:26 +02:00
Andy Shevchenko c64ffff7a9 i2c: core: Allow empty id_table in ACPI case as well
For now empty ID table is not allowed with ACPI and prevents driver to
be probed.

Add a check to allow empty ID table.

This introduces a helper i2c_acpi_match_device().

Note, we rename some static function in i2c-core-acpi.c to distinguish
with public API.

Fixes: da10c06a04 ("i2c: Make I2C ID tables non-mandatory for DT'ed devices")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Rajmohan Mani <rajmohan.mani@intel.com>
Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com>
[wsa: needed to get some drivers probed again]
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-07-31 15:50:33 +02:00
Hans de Goede 3a4991a986 i2c: acpi: Do not create i2c-clients for LNXVIDEO ACPI devices
ACPI video devices get tagged by the kernel with the custom LNXVIDEO
HID so that normal pnp-id matching can be used and are handled by the
acpi-video driver.

Sometimes the ACPI nodes describing these contain a SERIAL_TYPE_I2C ACPI
resource. Before this commit the presence of this resource would cause the
i2c-core to create a /sys/bus/i2c/devices/i2c-LNXVIDEO:00 device for this
with a modalias of: "i2c:LNXVIDEO:00".

There is no i2c driver for this custom HID, the acpi-video driver binds
directly to the ACPI device /sys/bus/acpi/devices/LNXVIDEO\:00 which has
a modalias of "acpi:LNXVIDEO:" .

Not only is the creation of an i2c-client for this undesirable, it is
actually causing problems. This weird pseudo-resource claims an i2c
speed of 100KHz and typically points to the i2c bus which is used by the
touchscreen controller. Some touchscreen controllers only work properly at
400KHz, at 100KHz they cause errors like these:

i2c_designware 80860F41:03: i2c_dw_handle_tx_abort: lost arbitration
i2c_designware 80860F41:03: i2c_dw_handle_tx_abort: lost arbitration
i2c_designware 80860F41:03: i2c_dw_handle_tx_abort: lost arbitration
i2c_designware 80860F41:03: i2c_dw_handle_tx_abort: lost arbitration
silead_ts i2c-MSSL1680:00: Registers clear error -11

This commit makes the i2c-core ignore LNXVIDEO compatible ACPI devices
which has 2 positive results:

1) The bogus i2c-client for these is no longer created.
2) i2c_acpi_lookup_speed now ignores the 100KHz speed from the pseudo
i2c-resouce and properly returns 400KHz as speed for the touchscreen
i2c bus, fixing the touchscreen not working on various devies.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-07-04 15:57:34 +02:00
Wolfram Sang 53f8f7c5cf i2c: break out ACPI support into separate file
Removes some ifdeffery. Also add the new file to the relevant
MAINTAINERS section.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2017-05-31 21:01:04 +02:00