From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hans de Goede Subject: Re: [PATCH v3 4/4] i2c: Add multi-instantiate pseudo driver Date: Wed, 8 Aug 2018 10:08:03 +0200 Message-ID: <594d2c14-6f93-98cb-100d-9cc307d1cee4@redhat.com> References: <20180807080539.17811-1-hdegoede@redhat.com> <20180807080539.17811-5-hdegoede@redhat.com> <7e68276c-2211-85d3-3e1f-2bc4b2d9f7d5@huawei.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 8bit Return-path: In-Reply-To: <7e68276c-2211-85d3-3e1f-2bc4b2d9f7d5@huawei.com> Content-Language: en-US Sender: linux-kernel-owner@vger.kernel.org To: John Garry , "Rafael J . Wysocki" , Len Brown , Andy Shevchenko , Mika Westerberg , Darren Hart , Wolfram Sang Cc: Srinivas Pandruvada , linux-acpi@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-kernel@vger.kernel.org, Heikki Krogerus , linux-i2c@vger.kernel.org List-Id: linux-i2c@vger.kernel.org Hi, On 07-08-18 14:46, John Garry wrote: > On 07/08/2018 09:05, Hans de Goede wrote: >> On systems with ACPI instantiated i2c-clients, normally there is 1 fw_node >> per i2c-device and that fw-node contains 1 I2cSerialBus resource for that 1 >> i2c-device. >> >> But in some rare cases the manufacturer has decided to describe multiple >> i2c-devices in a single ACPI fwnode with multiple I2cSerialBus resources. >> >> An earlier attempt to fix this in the i2c-core resulted in a lot of extra >> code to support this corner-case. >> >> This commit introduces a new i2c-multi-instantiate driver which fixes this >> in a different way. This new driver can be built as a module which will >> only loaded on affected systems. >> >> This driver will instantiate a new i2c-client per I2cSerialBus resource, >> using the driver_data from the acpi_device_id it is binding to to tell it >> which chip-type (and optional irq-resource) to use when instantiating. >> >> Note this driver depends on a platform device being instantiated for the >> ACPI fwnode, see the i2c_multi_instantiate_ids list of ACPI device-ids in >> drivers/acpi/scan.c: acpi_device_enumeration_by_parent(). >> >> Signed-off-by: Hans de Goede >> --- >>  MAINTAINERS                                  |   6 + >>  drivers/platform/x86/Kconfig                 |  11 ++ >>  drivers/platform/x86/Makefile                |   1 + >>  drivers/platform/x86/i2c-multi-instantiate.c | 131 +++++++++++++++++++ >>  4 files changed, 149 insertions(+) >>  create mode 100644 drivers/platform/x86/i2c-multi-instantiate.c >> >> diff --git a/MAINTAINERS b/MAINTAINERS >> index 9b377508f24f..09e16d76cab7 100644 >> --- a/MAINTAINERS >> +++ b/MAINTAINERS >> @@ -6657,6 +6657,12 @@ F:    drivers/i2c/i2c-mux.c >>  F:    drivers/i2c/muxes/ >>  F:    include/linux/i2c-mux.h >> >> +I2C MULTI INSTANTIATE DRIVER >> +M:    Hans de Goede >> +L:    linux-i2c@vger.kernel.org >> +S:    Maintained >> +F:    drivers/drivers/platform/x86/i2c-multi-instantiate.c > > This path looks incorrect > >> + >>  I2C MV64XXX MARVELL AND ALLWINNER DRIVER >>  M:    Gregory CLEMENT >>  L:    linux-i2c@vger.kernel.org >> diff --git a/drivers/platform/x86/Kconfig b/drivers/platform/x86/Kconfig >> index 85a93453237c..8256629f58f7 100644 >> --- a/drivers/platform/x86/Kconfig >> +++ b/drivers/platform/x86/Kconfig >> @@ -1219,6 +1219,17 @@ config INTEL_CHTDC_TI_PWRBTN >>        To compile this driver as a module, choose M here: the module >>        will be called intel_chtdc_ti_pwrbtn. >> >> +config I2C_MULTI_INSTANTIATE >> +    tristate "I2C multi instantiate pseudo device driver" >> +    depends on I2C && ACPI >> +    help >> +      Some ACPI bases systems list multiple i2c-devices in a single ACPI > > I guess that this should be "Some ACPI-based systems" Thanks, both fixed for v4 of the patchset. Regards, Hans > >> +      firmware-node. This driver will instantiate separate i2c-clients >> +      for each device in the firmware-node. >> + >> +      To compile this driver as a module, choose M here: the module >> +      will be called i2c-multi-instantiate. >> + > > Thanks, > John >