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The method to acquire the input interrupt was working in a platform data
based board, but was failing in a device-tree one when the gpio
controller was probed after pxa_cplds.
Use platform_get_irq() to benefit from the probe deferral
mechanism. Moreover, as seen in dm9000.c development, platform_get_irq()
doesn't honor the irq type IO resource (ie. edge rising for example),
and it must be passed again at irq request in a not device-tree build,
hence the irq_get_trigger_type() call.
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
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Since its initial commit, the driver is buggy for multiple interrupts
handling. The translation from the former lubbock.c file was not
complete, and might stall all interrupt handling when multiple
interrupts occur.
This is especially true when inside the interrupt handler and if a new
interrupt comes and is not handled, leaving the output line still held,
and not creating a transition as the GPIO block behind would expect to
trigger another cplds_irq_handler() call.
For the record, the hardware is working as follows.
The interrupt mechanism relies on :
- one status register
- one mask register
Let's suppose the input irq lines are called :
- i_sa1111
- i_lan91x
- i_mmc_cd
Let's suppose the status register for each irq line is called :
- status_sa1111
- status_lan91x
- status_mmc_cd
Let's suppose the interrupt mask for each irq line is called :
- irqen_sa1111
- irqen_lan91x
- irqen_mmc_cd
Let's suppose the output irq line, connected to GPIO0 is called :
- o_gpio0
The behavior is as follows :
- o_gpio0 = not((status_sa1111 & irqen_sa1111) |
(status_lan91x & irqen_lan91x) |
(status_mmc_cd & irqen_mmc_cd))
=> this is a N-to-1 NOR gate and multiple AND gates
- irqen_* is exactly as programmed by a write to the FPGA
- status_* behavior is governed by a bi-stable D flip-flop
=> on next FPGA clock :
- if i_xxx is high, status_xxx becomes 1
- if i_xxx is low, status_xxx remains as it is
- if software sets status_xxx to 0, the D flip-flop is reset
=> status_xxx becomes 0
=> on next FPGA clock cycle, if i_xxx is high, status_xxx becomes
1 again
Fixes: fc9e38c0f4d3 ("ARM: pxa: lubbock: use new pxa_cplds driver")
Reported-by: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
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"base_irq" needs to be signed for the error handling to work. Also we
can remove the initialization because we re-assign it later.
Fixes: aa8d6b73ea33 ('ARM: pxa: pxa_cplds: add lubbock and mainstone IO')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
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Historically, this support was in arch/arm/mach-pxa/lubbock.c and
arch/arm/mach-pxa/mainstone.c. When gpio-pxa was moved to drivers/pxa,
it became a driver, and its initialization and probing happened at
postcore initcall. The lubbock code used to install the chained lubbock
interrupt handler at init_irq() time.
The consequence of the gpio-pxa change is that the installed chained irq
handler lubbock_irq_handler() was overwritten in pxa_gpio_probe(_dt)(),
removing :
- the handler
- the falling edge detection setting of GPIO0, which revealed the
interrupt request from the lubbock IO board.
As a fix, move the gpio0 chained handler setup to a place where we have
the guarantee that pxa_gpio_probe() was called before, so that lubbock
handler becomes the true IRQ chained handler of GPIO0, demuxing the
lubbock IO board interrupts.
This patch moves all that handling to a mfd driver. It's only purpose
for the time being is the interrupt handling, but in the future it
should encompass all the motherboard CPLDs handling :
- leds
- switches
- hexleds
The same logic applies to mainstone board.
Fixes: 157d2644cb0c ("ARM: pxa: change gpio to platform device")
Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Acked-by: Arnd Bergmann <arnd@arndb.de>
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