From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dustin Byford Subject: [RFC v2 1/1] i2c: acpi: scan ACPI enumerated I2C mux channels Date: Fri, 14 Aug 2015 12:31:33 -0700 Message-ID: <1439580693-5538-2-git-send-email-dustin@cumulusnetworks.com> References: <1439580693-5538-1-git-send-email-dustin@cumulusnetworks.com> Return-path: In-Reply-To: <1439580693-5538-1-git-send-email-dustin@cumulusnetworks.com> Sender: linux-kernel-owner@vger.kernel.org To: Wolfram Sang , linux-i2c@vger.kernel.org Cc: linux-kernel@vger.kernel.org, rjw@rjwysocki.net, linux-acpi@vger.kernel.org List-Id: linux-acpi@vger.kernel.org Set an ACPI companion for I2C mux channels enumerated through ACPI and ensure they are scanned for devices. Signed-off-by: Dustin Byford --- drivers/i2c/i2c-core.c | 10 ++++++++++ drivers/i2c/i2c-mux.c | 8 ++++++++ 2 files changed, 18 insertions(+) diff --git a/drivers/i2c/i2c-core.c b/drivers/i2c/i2c-core.c index c83e4d1..23cc8e9 100644 --- a/drivers/i2c/i2c-core.c +++ b/drivers/i2c/i2c-core.c @@ -171,8 +171,18 @@ static void acpi_i2c_register_devices(struct i2c_adapter *adap) if (!adap->dev.parent) return; + /* + * Determine where to start walking the ACPI namespace. The common + * case is to start at the adapter's parent device. However, in + * the case of a "virtual" I2C adapter created to represent a mux + * channel the parent dev (pointing to the mux device) does not + * have an ACPI handle. Walk starting at the adapter instead. + */ handle = ACPI_HANDLE(adap->dev.parent); if (!handle) + handle = ACPI_HANDLE(&adap->dev); + + if (!handle) return; status = acpi_walk_namespace(ACPI_TYPE_DEVICE, handle, 1, diff --git a/drivers/i2c/i2c-mux.c b/drivers/i2c/i2c-mux.c index 2ba7c0f..2731b99 100644 --- a/drivers/i2c/i2c-mux.c +++ b/drivers/i2c/i2c-mux.c @@ -25,6 +25,7 @@ #include #include #include +#include /* multiplexer per channel data */ struct i2c_mux_priv { @@ -173,6 +174,13 @@ struct i2c_adapter *i2c_add_mux_adapter(struct i2c_adapter *parent, } } + /* + * Now try to populate the mux adapter's ACPI node. + */ + if (has_acpi_companion(mux_dev)) + acpi_preset_companion(&priv->adap.dev, ACPI_COMPANION(mux_dev), + chan_id); + if (force_nr) { priv->adap.nr = force_nr; ret = i2c_add_numbered_adapter(&priv->adap); -- 2.1.4