This is a follow up patches after adding i2c mux adapter for bypass
mode. Potentially many different types of sensor can be attached to
INVMPU6XXX device, which can be connected to main cpu i2c bus in
bypass mode.
Why do we need this?
The system ACPI table entry will consist of only one device for
INV6XXX, assuming that this driver will handle all connected sensors.
That is not true for the Linux driver. There are bunch of IIO drivers
for each sensors, hence we created a mux on this device. So to load
these additional drivers, we need to create i2c devices for them
in this driver using this mux adapter.
There are multiple options:
1. Use the auto detect feature, this needs a new i2c class for the
adapter as the existing HWMON class is not acceptable. Also the
autodetect has overhead of executing detect method for each
matching class of adapters.
This is a simple implementation. This option was previously submitted
with not a happy feedback.
2. Option is use ACPI magic and parse the configuration data. What
we need to create a i2c device at a minimum is address and a name.
Address can be obtained for secondary device in more or less in a
standard way from using _CRS element. But there is no name. To get
name we need to process proprietary vendor data. Not having name is
not fun, as you have to create device using the device name of
INVN6XXXX, respecting driver duplicate name space restriction.
Also each client driver needs to have this name in the id table.
Since multiple driver can be loaded, the driver should be able to
detect its presence and gracefully exit for the other client driver
to take it over.
So we use two step process:
- Use DMI to id platform and parse propritery data. This is not uncommon
for many x86 platform specific driver. We will get both name and address.
The change created necessary infrastructure to add more properitery vendor
data parsing.
- If DMI match fails, then create device on INV6XXX-client (we can't
create with same name as INV6XXX as it will cause duplicate name and driver
model will reject.) With this each client sensor driver which needs to get
attached via INV6XXXX, need this name in the id table and detect the
physical presence of sensor in probe and exit if not found.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This chip allows some limited number of sensors connected to it as
slaves, which can be directly accessed by register interface of this
driver.But the current upstream driver doesn't support such mode.
To attach such slaves to main processor i2c bus, chip has to be set
up in bypass mode. This change adds i2c mux, which will enable/disable
this mode for transaction to/from such slave devices.
This was discussed for a while in mailing list, this was the outcome:
Reference:
http://www.spinics.net/lists/linux-iio/msg12126.htmlhttp://comments.gmane.org/gmane.linux.kernel.iio/11470
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Reviewed-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Adding MPU6500 in target list for this driver.
Description:
Source
Document: MPU-6500 Register Map and Descriptions Revision 2.1
Section 3: Register Map
This section describes difference in terms device programmability
between MPU6050 and MPU6500.
These are different registers, which differs between MPU6050 and
MPU6500.
Addr Name
---------------------
1E LP_ACCEL_ODR
6C PWR_MGMT_2
77 XA_OFFSET_H
78 XA_OFFSET_L
7A YA_OFFSET_H
7B YA_OFFSET_L
7D ZA_OFFSET_H
7E ZA_OFFSET_L
But the current MPU6050 driver doesn't use registers which are different
except PWR_MGMT_2. The difference is support of "LP_WAKE_CTRL" at bit6-7
in MPU6050 mode. In MPU6500 they are not defined.
In current mpu6050 driver, only values used for this register are for
standby mode for gyro and accelerometer.
In both case frequency of wakeups is set to default and not using
bit 6-7.
So this driver van as well support MPU6500. In addition MPU6500 can
run MPU6050 mode by changing device trim settings.
So changing config comments to allow MPU6500 to use this driver.
When the driver is enhanced to support more functions, i2c driver
data INV_MPU6500 or "WHO_AM_I" register can be used to add additional
functionality.
Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
This the basic functional Invensense MPU6050 Device driver.
Signed-off-by: Ge Gao <ggao@invensense.com>
Reviewed-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: Jonathan Cameron <jic23@kernel.org>
Srinivas Pandruvada