linux-toradex.git/drivers/gpio/gpio-pch.c, branch v3.4.83

gpio: pch9: Use proper flow type handlers

2012-05-12T00:18:50+00:00

Jean-Francois Dagenais reported:

 Configuring a gpio pin with the gpio-pch driver with
 "IRQF_TRIGGER_LOW | IRQF_ONESHOT" generates an interrupt storm for
 threaded ISR until the ISR thread actually gets to physically clear
 the interrupt on the triggering chip!! The immediate observable
 symptom is the high CPU usage for my ISR thread task and the
 interrupt count in /proc/interrupts incrementing radically.

The driver is wrong in several ways:

1) Using handle_simple_irq() does not provide proper flow control
   handling. In the case of oneshot threaded handlers for the
   demultiplexed interrupts this results in an interrupt storm because
   the simple handler does not deal with masking/unmasking.  Even
   without threaded oneshot handlers an interrupt storm for level type
   interrupts can easily be triggered when the interrupt is disabled
   and the interrupt line is activated from the device.

2) Acknowlegding the demultiplexed interrupt before calling the
   handler is wrong for level type interrupts.

3) The set_type function unconditionally enables the interrupt. It's
   supposed to set the type and nothing else. The unmasking is done by
   the core code.

Move the acknowledge code into a separate function and add it to the
demux irqchip callbacks.

Remove the unconditional enabling from the set_type() callback and set
the proper flow handlers depending on the selected type (level/edge).

Reported-and-tested-by: Jean-Francois Dagenais 
Signed-off-by: Thomas Gleixner 
Signed-off-by: Grant Likely

gpio: Add missing spin_lock_init in gpio-pch driver

2012-02-02T04:59:15+00:00

This bug was introduced by commit d568a681
"gpio-pch: add spinlock in suspend/resume processing"
which adds a spinlock to struct pch_gpio but never init the spinlock.

Reported-by: Tomoya MORINAGA 
Signed-off-by: Axel Lin 
Acked-by: Linus Walleij 
Signed-off-by: Grant Likely

gpio-pch: cleanup __iomem annotation usage

2012-01-16T16:12:24+00:00

The __iomem annotation is to be used together with pointers used
as iowrite32() parameter. For more details see [1] and [2].

This patch will remove the following sparse warnings ("make C=1"):
 * warning: incorrect type in assignment (different address spaces)
 * warning: incorrect type in argument 1 (different address spaces)
 * warning: incorrect type in argument 2 (different address spaces)

References:
[1] A new I/O memory access mechanism (Sep 15, 2004)
    http://lwn.net/Articles/102232/

[2] Being more anal about iospace accesses (Sep 15, 2004)
    http://lwn.net/Articles/102240/

Signed-off-by: Márton Németh 
Signed-off-by: Grant Likely

gpio-pch: cleanup NULL pointer checking

2012-01-16T16:12:24+00:00

This patch will remove the following sparse warning ("make C=1"):
 * warning: Using plain integer as NULL pointer

Signed-off-by: Márton Németh 
Signed-off-by: Grant Likely

pch_gpio: Change company name OKI SEMICONDUCTOR to LAPIS Semiconductor

2011-12-12T20:40:16+00:00

On October 1 in 2011,
OKI SEMICONDUCTOR Co., Ltd. changed the company name in to LAPIS Semiconductor Co., Ltd.

Signed-off-by: Tomoya MORINAGA 
Signed-off-by: Grant Likely

pch_gpio: Support new device LAPIS Semiconductor ML7831 IOH

2011-12-12T20:40:15+00:00

ML7831 is companion chip for Intel Atom E6xx series.

Signed-off-by: Tomoya MORINAGA 
Signed-off-by: Grant Likely

drivers/gpio: Fix drivers who are implicit users of module.h

2011-10-31T23:31:47+00:00

A pending cleanup will mean that module.h won't be implicitly
everywhere anymore.  Make sure the modular drivers in gpio
are actually calling out for  explicitly in advance.

Signed-off-by: Paul Gortmaker

gpio-pch: Use NUMA_NO_NODE not GFP_KERNEL

2011-10-20T01:01:29+00:00

Currently, GFP_KERNEL is used as parameter of irq_alloc_descs like below.

          irq_base = irq_alloc_descs(-1, IOH_IRQ_BASE, num_ports[j],
                                     GFP_KERNEL);

This is not true.
So, this patch uses NUMA_NO_NODE not GFP_KERNEL.

Reported-by: Dan Carpenter 
Reported-by: David Rientjes 
Signed-off-by: Tomoya MORINAGA 
Acked-by: David Rientjes 
Signed-off-by: Grant Likely

gpio-pch: Support interrupt function

2011-10-05T17:59:17+00:00

Signed-off-by: Tomoya MORINAGA 
Signed-off-by: Grant Likely

gpio-pch: Save register value in suspend()

2011-10-05T17:59:17+00:00

Currently, when suspend is occurred, register im0/1 and gpio_use_sel are not
saved.
This patch modifies so that register im0/1 and gpio_use_sel are saved.

Signed-off-by: Tomoya MORINAGA 
Signed-off-by: Grant Likely