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path: root/drivers/mfd/dln2.c
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2020-08-13mfd: dln2: Run event handler loop under spinlockAndy Shevchenko
The event handler loop must be run with interrupts disabled. Otherwise we will have a warning: [ 1970.785649] irq 31 handler lineevent_irq_handler+0x0/0x20 enabled interrupts [ 1970.792739] WARNING: CPU: 0 PID: 0 at kernel/irq/handle.c:159 __handle_irq_event_percpu+0x162/0x170 [ 1970.860732] RIP: 0010:__handle_irq_event_percpu+0x162/0x170 ... [ 1970.946994] Call Trace: [ 1970.949446] <IRQ> [ 1970.951471] handle_irq_event_percpu+0x2c/0x80 [ 1970.955921] handle_irq_event+0x23/0x43 [ 1970.959766] handle_simple_irq+0x57/0x70 [ 1970.963695] generic_handle_irq+0x42/0x50 [ 1970.967717] dln2_rx+0xc1/0x210 [dln2] [ 1970.971479] ? usb_hcd_unmap_urb_for_dma+0xa6/0x1c0 [ 1970.976362] __usb_hcd_giveback_urb+0x77/0xe0 [ 1970.980727] usb_giveback_urb_bh+0x8e/0xe0 [ 1970.984837] tasklet_action_common.isra.0+0x4a/0xe0 ... Recently xHCI driver switched to tasklets in the commit 36dc01657b49 ("usb: host: xhci: Support running urb giveback in tasklet context"). The handle_irq_event_* functions are expected to be called with interrupts disabled and they rightfully complain here because we run in tasklet context with interrupts enabled. Use a event spinlock to protect event handler from being interrupted. Note, that there are only two users of this GPIO and ADC drivers and both of them are using generic_handle_irq() which makes above happen. Fixes: 338a12814297 ("mfd: Add support for Diolan DLN-2 devices") Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2020-03-30mfd: dln2: Allow to be enumerated via ACPIAndy Shevchenko
On some platforms user may want to enumerate DLN2 device, its children, to be enumerated via ACPI. In order to achieve this, let's distinguish children by _ADR value. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2020-03-30mfd: dln2: Fix sanity checking for endpointsAndy Shevchenko
While the commit 2b8bd606b1e6 ("mfd: dln2: More sanity checking for endpoints") tries to harden the sanity checks it made at the same time a regression, i.e. mixed in and out endpoints. Obviously it should have been not tested on real hardware at that time, but unluckily it didn't happen. So, fix above mentioned typo and make device being enumerated again. While here, introduce an enumerator for magic values to prevent similar issue to happen in the future. Fixes: 2b8bd606b1e6 ("mfd: dln2: More sanity checking for endpoints") Cc: Oliver Neukum <oneukum@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2020-01-24mfd: dln2: More sanity checking for endpointsOliver Neukum
It is not enough to check for the number of endpoints. The types must also be correct. Reported-and-tested-by: syzbot+48a2851be24583b864dc@syzkaller.appspotmail.com Signed-off-by: Oliver Neukum <oneukum@suse.com> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Lee Jones <lee.jones@linaro.org>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 372Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 135 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531081036.435762997@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-07-27mfd: dln2: Use irqsave() in USB's complete callbackSebastian Andrzej Siewior
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>
2015-03-26mfd: dln2: Use msecs_to_jiffies for time conversionNicholas Mc Guire
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>
2015-01-22mfd: dln2: Add suspend/resume functionalityOctavian Purdila
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>
2015-01-22mfd: dln2: Add start/stop RX URBs helpersOctavian Purdila
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>
2014-11-25mfd: dln2: add support for USB-SPI moduleLaurentiu Palcu
Signed-off-by: Laurentiu Palcu <laurentiu.palcu@intel.com>
2014-11-19mfd: dln2: A couple endian fixesDan Carpenter
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>
2014-11-19mfd: dln2: Add a limit check for invalid echoOctavian Purdila
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>
2014-11-19mfd: dln2: Fix _dln2_transfer return codeOctavian Purdila
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>
2014-11-10mfd: Add support for Diolan DLN-2 devicesOctavian Purdila
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>