talos-obmc-linux/drivers/gpio, branch dev-4.13

gpio/aspeed: Use a cache of output data registers

2018-05-11T10:48:06+00:00

The current driver does a read/modify/write of the output registers when changing a bit in __aspeed_gpio_set(). This is sub-optimal for a couple of reasons: - If any of the neighbouring GPIOs (sharing the shared register) isn't (yet) configured as an output, it will read the current input value, and then apply it to the output latch, which may not be what the user expects. There should be no bug in practice as aspeed_gpio_dir_out() will establish a new value but it's not great either. - The GPIO block in the aspeed chip is clocked rather slowly (typically 25Mhz). That extra MMIO read halves the maximum speed at which we can toggle the GPIO. This provides a significant performance improvement to the GPIO based FSI master. Signed-off-by: Benjamin Herrenschmidt Reviewed-by: Christopher Bostic Reviewed-by: Andrew Jeffery Signed-off-by: Joel Stanley

gpio/aspeed: Set output latch before changing direction

2018-05-11T10:48:01+00:00

In aspeed_gpio_dir_out(), we need to establish the new output value in the output latch *before* we change the direction to output in order to avoid a glitch on the output line if the previous value of the latch was different. Signed-off-by: Benjamin Herrenschmidt Reviewed-by: Christopher Bostic Reviewed-by: Andrew Jeffery Signed-off-by: Joel Stanley

gpio: gpiolib: Generalise state persistence beyond sleep

2018-02-08T06:04:00+00:00

General support for state persistence is added to gpiolib with the introduction of a new pinconf parameter to propagate the request to hardware. The existing persistence support for sleep is adapted to include hardware support if the GPIO driver provides it. Persistence continues to be enabled by default; in-kernel consumers can opt out, but userspace (currently) does not have a choice. The *_SLEEP_MAY_LOSE_VALUE and *_SLEEP_MAINTAIN_VALUE symbols are renamed, dropping the SLEEP prefix to reflect that the concept is no longer sleep-specific. I feel that renaming to just *_MAY_LOSE_VALUE could initially be misinterpreted, so I've further changed the symbols to *_TRANSITORY and *_PERSISTENT to address this. The sysfs interface is modified only to keep consistency with the chardev interface in enforcing persistence for userspace exports. Signed-off-by: Andrew Jeffery Reviewed-by: Charles Keepax Acked-by: Rob Herring Signed-off-by: Linus Walleij (cherry picked from commit e10f72bf4b3e8885c1915a119141481e7fc45ca8) Signed-off-by: Joel Stanley

gpio: aspeed: Add support for reset tolerance

2018-02-08T06:04:00+00:00

Use the new pinconf parameter for state persistence to expose the associated capability of the Aspeed GPIO controller. Signed-off-by: Andrew Jeffery Reviewed-by: Joel Stanley Signed-off-by: Linus Walleij (cherry picked from commit 1b43d26985745901c87e0dca44c9b57896062306) Signed-off-by: Joel Stanley

gpio: aspeed: Remove reference to clock name in debounce warning message

2017-11-28T04:10:02+00:00

HPLL is in fact not the clock we need. Remove the description of which clock we failed to find a phandle to in order to avoid any further error. Signed-off-by: Andrew Jeffery Acked-by: Joel Stanley Signed-off-by: Linus Walleij (cherry picked from commit 754c04582a98fa2a24ff1b4c4b88964b114eb526) Signed-off-by: Joel Stanley

gpio: mvebu: Fix cause computation in irq handler

2017-08-14T13:00:43+00:00

When switching to regmap, the way to compute the irq cause was reorganized. However while doing it, a typo was introduced: a 'xor' replaced a 'and'. This lead to wrong behavior in the interrupt handler ans one of the symptom was wrong irq handler called on the Armada 388 GP: "->handle_irq(): c016303c, handle_bad_irq+0x0/0x278 ->irq_data.chip(): c0b0ec0c, 0xc0b0ec0c ->action(): (null) IRQ_NOPROBE set IRQ_NOREQUEST set unexpected IRQ trap at vector 00 irq 0, desc: ee804800, depth: 1, count: 0, unhandled: 0" Fixes: 2233bf7a92e7 ("gpio: mvebu: switch to regmap for register access") Signed-off-by: Gregory CLEMENT Signed-off-by: Linus Walleij

gpio: reject invalid gpio before getting gpio_desc

2017-08-14T13:00:43+00:00

Check user-given gpio number and reject it before calling gpio_to_desc() because gpio_to_desc() is for kernel driver and it expects given gpio number is valid (means 0 to 511). If given number is invalid, gpio_to_desc() calls WARN() and dump registers and stack for debug. This means user can easily kick WARN() just by writing invalid gpio number (e.g. 512) to /sys/class/gpio/export. Fixes: 0e9a5edf5d01 ("gpio: fix deferred probe detection for legacy API") Signed-off-by: Masami Hiramatsu Reviewed-by: Andy Shevchenko Signed-off-by: Linus Walleij

gpio: tegra: fix unbalanced chained_irq_enter/exit

2017-08-02T08:42:38+00:00

When more than one GPIO IRQs are triggered simultaneously, tegra_gpio_irq_handler() called chained_irq_exit() multiple times for one chained_irq_enter(). Fixes: 3c92db9ac0ca3eee8e46e2424b6c074e2e394ad9 Signed-off-by: Michał Mirosław [Also changed the variable to a bool] Signed-off-by: Linus Walleij

gpiolib: skip unwanted events, don't convert them to opposite edge

2017-08-01T12:07:35+00:00

The previous fix for filtering out of unwatched events was not entirely correct. Instead of skipping the events we don't want, they are now interpreted as events with opposing edge. In order to fix it: always read the GPIO line value on interrupt and only emit the event if it corresponds with the event type we requested. Cc: stable@vger.kernel.org Fixes: ad537b822577 ("gpiolib: fix filtering out unwanted events") Signed-off-by: Bartosz Golaszewski Signed-off-by: Linus Walleij

gpio: exar: Use correct property prefix and document bindings

2017-08-01T11:43:55+00:00

The device-specific property should be prefixed with the vendor name, not "linux,", as Linus Walleij pointed out. Change this and document the bindings of this platform device. We didn't ship the old binding in a release yet. So we can still change it without breaking an official API. Fixes: 380b1e2f3a2f ("gpio-exar/8250-exar: Make set of exported GPIOs configurable") Signed-off-by: Jan Kiszka Acked-by: Rob Herring Signed-off-by: Linus Walleij