Commit Graph

9 Commits

Author SHA1 Message Date
Sebastian Andrzej Siewior 50d44f82c7 mfd: dln2: Use irqsave() in USB's complete callback
The USB completion callback does not disable interrupts while acquiring
the lock. We want to remove the local_irq_disable() invocation from
__usb_hcd_giveback_urb() and therefore it is required for the callback
handler to disable the interrupts while acquiring the lock.
The callback may be invoked either in IRQ or BH context depending on the
USB host controller.
Use the _irqsave() variant of the locking primitives.

Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2018-07-27 08:13:25 +01:00
Nicholas Mc Guire 48579a9ae8 mfd: dln2: Use msecs_to_jiffies for time conversion
Converting milliseconds to jiffies by "val * HZ / 1000" is technically
OK but msecs_to_jiffies(val) is the cleaner solution and handles all
corner cases correctly. This is a minor API consolidation only and
should make things more readable.

Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-03-26 14:20:18 +00:00
Octavian Purdila 3daa122d6b mfd: dln2: Add suspend/resume functionality
Without suspend/resume functionality in the USB driver the USB core
will disconnect and reconnect the DLN2 port and because the GPIO
framework does not yet support removal of an in-use controller a
suspend/resume operation will result in a crash.

This patch provides suspend and resume functions for the DLN2 driver
so that the above scenario is avoided, if the host controller does not
drop VBUS during suspend, since in this case the device state is
preserved.

We chose not implemented reset_resume so that if the host controller
does drop VBUS the resume path will go through above the
disconnect/reconnect process since it is probably better to fix the
GPIO framework disconnect issue then to save and restore the device
state for every driver.

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-01-22 15:56:01 +00:00
Octavian Purdila ee231aeed9 mfd: dln2: Add start/stop RX URBs helpers
This is in preparation for adding suspend / resume support.

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2015-01-22 15:55:58 +00:00
Laurentiu Palcu 21cf3318d6 mfd: dln2: add support for USB-SPI module
Signed-off-by: Laurentiu Palcu <laurentiu.palcu@intel.com>
2014-11-25 16:18:57 +00:00
Dan Carpenter 2fc2b4846c mfd: dln2: A couple endian fixes
Sparse catches a couple endian bugs.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-11-19 17:12:59 +00:00
Octavian Purdila 00ee7a37fd mfd: dln2: Add a limit check for invalid echo
The echo field in dln2_transfer_complete comes directly from an USB
transfer and we should not trust it is valid.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-11-19 17:12:50 +00:00
Octavian Purdila 7ca2b1c672 mfd: dln2: Fix _dln2_transfer return code
If wait_for_completion_interruptible_timeout returns a positive value
it may be propagated as the return value of _dln2_transfer. This
contradicts the documentation of the function and exposes unnecessary
internals to the callers.

This patch makes sure to set the return value to 0 in that case.

Reported-by: Julia Lawall <julia.lawall@lip6.fr>
Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-11-19 17:12:19 +00:00
Octavian Purdila 338a128142 mfd: Add support for Diolan DLN-2 devices
This patch implements the USB part of the Diolan USB-I2C/SPI/GPIO
Master Adapter DLN-2. Details about the device can be found here:

https://www.diolan.com/i2c/i2c_interface.html.

Information about the USB protocol can be found in the Programmer's
Reference Manual [1], see section 1.7.

Because the hardware has a single transmit endpoint and a single
receive endpoint the communication between the various DLN2 drivers
and the hardware will be muxed/demuxed by this driver.

Each DLN2 module will be identified by the handle field within the DLN2
message header. If a DLN2 module issues multiple commands in parallel
they will be identified by the echo counter field in the message header.

The DLN2 modules can use the dln2_transfer() function to issue a
command and wait for its response. They can also register a callback
that is going to be called when a specific event id is generated by
the device (e.g. GPIO interrupts). The device uses handle 0 for
sending events.

[1] https://www.diolan.com/downloads/dln-api-manual.pdf

Signed-off-by: Octavian Purdila <octavian.purdila@intel.com>
Reviewed-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2014-11-10 16:30:05 +00:00