gpio: mockup: improve the user-space testing interface

From: Bartosz Golaszewski <[email protected]>

Marc,

as discussed. This is hopefully the last version. The irq_set_type() callback now only accepts edge triggers.

v1 -> v2:
- instead of providing the irq_sim_get_type() helper, move the irq type logic into the simulator and provide a helper that allows users to specify the type of the fired interrupt

v2 -> v3:
- switch back to having irq_sim_type() and put the line state logic into the GPIO testing module

v3 -> v4:
- drop irq_sim_get_type() and use a notifier chain instead so that any change in type configuration can be pushed out to interested users
- change the locking mechanism in gpio-mockup to a spinlock as we can't take a mutex when a hardirq-safe spinlock in irq_desc is being held when the irq_set_type() callback is called
- refuse to set any other type than falling or rising edge in irq_set_config

v4 -> v5:
- drop the notifier, use irqd_set_trigger_type() instead

v5 -> v6:
- same as v5, but we're now validating the trigger type and only allow edge triggers

Bartosz Golaszewski (7):
irq/irq_sim: add irq_set_type() callback
gpio: mockup: add locking
gpio: mockup: implement get_multiple()
gpio: mockup: don't create the debugfs link named after the label
gpio: mockup: change the type of 'offset' to unsigned int
gpio: mockup: change the signature of unlocked get/set helpers
gpio: mockup: rework debugfs interface

 drivers/gpio/gpio-mockup.c | 189 +++++++++++++++++++++++++++++++------
 kernel/irq/irq_sim.c       |  12 +++
 2 files changed, 174 insertions(+), 27 deletions(-)

2.20.1