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path: root/drivers/gpio/gpio-104-dio-48e.c
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2017-05-10Merge tag 'hwparam-20170420' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull hw lockdown support from David Howells: "Annotation of module parameters that configure hardware resources including ioports, iomem addresses, irq lines and dma channels. This allows a future patch to prohibit the use of such module parameters to prevent that hardware from being abused to gain access to the running kernel image as part of locking the kernel down under UEFI secure boot conditions. Annotations are made by changing: module_param(n, t, p) module_param_named(n, v, t, p) module_param_array(n, t, m, p) to: module_param_hw(n, t, hwtype, p) module_param_hw_named(n, v, t, hwtype, p) module_param_hw_array(n, t, hwtype, m, p) where the module parameter refers to a hardware setting hwtype specifies the type of the resource being configured. This can be one of: ioport Module parameter configures an I/O port iomem Module parameter configures an I/O mem address ioport_or_iomem Module parameter could be either (runtime set) irq Module parameter configures an I/O port dma Module parameter configures a DMA channel dma_addr Module parameter configures a DMA buffer address other Module parameter configures some other value Note that the hwtype is compile checked, but not currently stored (the lockdown code probably won't require it). It is, however, there for future use. A bonus is that the hwtype can also be used for grepping. The intention is for the kernel to ignore or reject attempts to set annotated module parameters if lockdown is enabled. This applies to options passed on the boot command line, passed to insmod/modprobe or direct twiddling in /sys/module/ parameter files. The module initialisation then needs to handle the parameter not being set, by (1) giving an error, (2) probing for a value or (3) using a reasonable default. What I can't do is just reject a module out of hand because it may take a hardware setting in the module parameters. Some important modules, some ipmi stuff for instance, both probe for hardware and allow hardware to be manually specified; if the driver is aborts with any error, you don't get any ipmi hardware. Further, trying to do this entirely in the module initialisation code doesn't protect against sysfs twiddling. [!] Note that in and of itself, this series of patches should have no effect on the the size of the kernel or code execution - that is left to a patch in the next series to effect. It does mark annotated kernel parameters with a KERNEL_PARAM_FL_HWPARAM flag in an already existing field" * tag 'hwparam-20170420' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: (38 commits) Annotate hardware config module parameters in sound/pci/ Annotate hardware config module parameters in sound/oss/ Annotate hardware config module parameters in sound/isa/ Annotate hardware config module parameters in sound/drivers/ Annotate hardware config module parameters in fs/pstore/ Annotate hardware config module parameters in drivers/watchdog/ Annotate hardware config module parameters in drivers/video/ Annotate hardware config module parameters in drivers/tty/ Annotate hardware config module parameters in drivers/staging/vme/ Annotate hardware config module parameters in drivers/staging/speakup/ Annotate hardware config module parameters in drivers/staging/media/ Annotate hardware config module parameters in drivers/scsi/ Annotate hardware config module parameters in drivers/pcmcia/ Annotate hardware config module parameters in drivers/pci/hotplug/ Annotate hardware config module parameters in drivers/parport/ Annotate hardware config module parameters in drivers/net/wireless/ Annotate hardware config module parameters in drivers/net/wan/ Annotate hardware config module parameters in drivers/net/irda/ Annotate hardware config module parameters in drivers/net/hamradio/ Annotate hardware config module parameters in drivers/net/ethernet/ ...
2017-04-20Annotate hardware config module parameters in drivers/gpio/David Howells
When the kernel is running in secure boot mode, we lock down the kernel to prevent userspace from modifying the running kernel image. Whilst this includes prohibiting access to things like /dev/mem, it must also prevent access by means of configuring driver modules in such a way as to cause a device to access or modify the kernel image. To this end, annotate module_param* statements that refer to hardware configuration and indicate for future reference what type of parameter they specify. The parameter parser in the core sees this information and can skip such parameters with an error message if the kernel is locked down. The module initialisation then runs as normal, but just sees whatever the default values for those parameters is. Note that we do still need to do the module initialisation because some drivers have viable defaults set in case parameters aren't specified and some drivers support automatic configuration (e.g. PNP or PCI) in addition to manually coded parameters. This patch annotates drivers in drivers/gpio/. Suggested-by: Alan Cox <gnomes@lxorguk.ukuu.org.uk> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> Acked-by: Linus Walleij <linus.walleij@linaro.org> cc: Alexandre Courbot <gnurou@gmail.com> cc: linux-gpio@vger.kernel.org
2017-03-16gpio: 104-dio-48e: make use of raw_spinlock variantsJulia Cartwright
The 104-dio-48e gpio driver currently implements an irq_chip for handling interrupts; due to how irq_chip handling is done, it's necessary for the irq_chip methods to be invoked from hardirq context, even on a a real-time kernel. Because the spinlock_t type becomes a "sleeping" spinlock w/ RT kernels, it is not suitable to be used with irq_chips. A quick audit of the operations under the lock reveal that they do only minimal, bounded work, and are therefore safe to do under a raw spinlock. Signed-off-by: Julia Cartwright <julia@ni.com> Acked-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-02-01gpio: 104-dio-48e: Add support for GPIO namesWilliam Breathitt Gray
This patch sets the gpio_chip names option with an array of GPIO line names that match the manual documentation for the ACCES 104-DIO-48E. This should make it easier for users to identify which GPIO line corresponds to a respective GPIO pin on the device. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-02-01gpio: 104-dio-48e: Remove unnecessary driver_data setWilliam Breathitt Gray
Setting driver_data was necessary to access private data in the dio48e_remove function. Now that the dio48e_remove function is gone, driver_data is no longer used. This patch removes the relevant code. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-26gpio: 104-dio-48e: Utilize devm_ functions in driver probe callbackWilliam Breathitt Gray
The devm_ resource manager functions allow memory to be automatically released when a device is unbound. This patch takes advantage of the resource manager functions and replaces the gpiochip_add_data call and request_irq call with the devm_gpiochip_add_data call and devm_request_irq call respectively. In addition, the dio48e_remove function has been removed as no longer necessary due to the use of the relevant devm_ resource manager functions. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2017-01-26gpio: 104-dio-48e: Add set_multiple callback function supportWilliam Breathitt Gray
The ACCES 104-DIO-48E series provides registers where 8 lines of GPIO may be set at a time. This patch add support for the set_multiple callback function, thus allowing multiple GPIO output lines to be set more efficiently in groups. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-06-08gpio: 104-dio-48e: Fix control port offset computation off-by-one errorWilliam Breathitt Gray
There are only two control ports, each controlling three distinct I/O ports. To compute the control port address offset for a respective I/O port, the I/O port address offset should be divided by 3; dividing by 2 may result in not only the wrong address offset but possibly also an out-of-bounds array memory access for a non-existent third control port. Fixes: 1b06d64f7374 ("gpio: Add GPIO support for the ACCES 104-DIO-48E") Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-05-02gpio: 104-dio-48e: Utilize the ISA bus driverWilliam Breathitt Gray
The ACCES 104-DIO-48E series communicates via the ISA bus. As such, it is more appropriate to use the ISA bus driver over the platform driver to control the ACCES 104-DIO-48E GPIO driver. This patch also adds support for multiple devices via the base and irq module array parameters. Each element of the base array corresponds to a discrete device; each element of the irq array corresponds to the respective device addressed in the respective base array element. Acked-by: Linus Walleij <linus.walleij@linaro.org> Cc: Alexandre Courbot <gnurou@gmail.com> Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-16gpio: 104-dio-48e: Use devm_request_regionWilliam Breathitt Gray
By the time request_region is called in the ACCES 104-DIO-48E GPIO driver, a corresponding device structure has already been allocated. The devm_request_region function should be used to help simplify the cleanup code and reduce the possible points of failure. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Reviewed-by: Alexandre Courbot <acourbot@nvidia.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-02-16gpio: misc: Pass correct license string to MODULE_LICENSEWilliam Breathitt Gray
The GPIO driver copyright boilerplate lacks the "or later" verbiage regarding GPL compliant distribution. The MODULE_LICENSE string should reflect the actual copyright license terms used. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2016-01-28gpio: Add GPIO support for the ACCES 104-DIO-48EWilliam Breathitt Gray
The ACCES 104-DIO-48E device provides 48 lines digital I/O via two Programmable Peripheral Interface (PPI) chips of type 82C55. Bit C3 at each 24-bit Group can be used as an external interrupt, triggered by a rising edge. This driver provides GPIO and IRQ support for these 48 channels of digital I/O. The base port address for the device may be configured via the dio_48e_base module parameter. The interrupt line number for the device may be configured via the dio_48e_irq module parameter. Signed-off-by: William Breathitt Gray <vilhelm.gray@gmail.com> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>