linux-toradex.git/drivers/pinctrl/pinctrl-single.c, branch v3.18.7

pinctrl: single: fix freudian slip

2014-09-05T08:33:25+00:00

commit 03e9f0cac5da6af85758276cb4624caf5911f2b9
"pinctrl: clean up after enable refactoring"
renamed the vtable callback .enable to .set_mux. The
renaming was done manually, and one of the alterations
contained a freudian slip. I confess, I am human.

Signed-off-by: Linus Walleij

pinctrl: clean up after enable refactoring

2014-09-04T08:05:07+00:00

commit 2243a87d90b42eb38bc281957df3e57c712b5e56
"pinctrl: avoid duplicated calling enable_pinmux_setting for a pin"
removed the .disable callback from the struct pinmux_ops,
making the .enable() callback the only remaining callback.

However .enable() is a bad name as it seems to imply that a
muxing can also be disabled. Rename the callback to .set_mux()
and also take this opportunity to clean out any remaining
mentions of .disable() from the documentation.

Acked-by: Stephen Warren 
Acked-by: Bjorn Andersson 
Acked-by: Fan Wu 
Signed-off-by: Linus Walleij

pinctrl: single: AM437x: Add pinctrl compatibility

2014-08-29T07:28:35+00:00

AM437x pinctrl definitions now differ from traditional 16 bit OMAP pin
ctrl definitions, in that all 32 bits are used to describe a single pin

Also the location of wakeupenable and event bits have changed.

Signed-off-by: Keerthy 
[nm@ti.com: minor updates]
Signed-off-by: Nishanth Menon 
Acked-by: Tony Lindgren 
Signed-off-by: Linus Walleij

pinctrl: single: Add DRA7 pinctrl compatibility

2014-08-29T07:27:44+00:00

DRA7 pinctrl definitions now differ from traditional 16 bit OMAP pin
ctrl definitions, in that all 32 bits are used to describe a single pin

Also the location of wakeupenable and event bits have changed.

Signed-off-by: Nishanth Menon 
Acked-by: Tony Lindgren 
Signed-off-by: Linus Walleij

pinctrl: pinctrl-single.c: Cleaning up wrong format string usage

2014-07-11T12:08:35+00:00

%d in format string used, but the type is unsigned int

This was found using a static code analysis program called cppcheck

Signed-off-by: Rickard Strandqvist 
Signed-off-by: Linus Walleij

pinctrl: pinctrl-single.c: Cleaning up values that are never used

2014-07-11T12:08:34+00:00

Remove variable that are never used

This was found using a static code analysis program called cppcheck.

Signed-off-by: Rickard Strandqvist 
Signed-off-by: Linus Walleij

pinctrl: avoid duplicated calling enable_pinmux_setting for a pin

2014-07-11T12:08:26+00:00

What the patch does:
1. Call pinmux_disable_setting ahead of pinmux_enable_setting
  each time pinctrl_select_state is called
2. Remove the HW disable operation in pinmux_disable_setting function.
3. Remove the disable ops in struct pinmux_ops
4. Remove all the disable ops users in current code base.

Notes:
1. Great thanks for the suggestion from Linus, Tony Lindgren and
   Stephen Warren and Everyone that shared comments on this patch.
2. The patch also includes comment fixes from Stephen Warren.

The reason why we do this:
1. To avoid duplicated calling of the enable_setting operation
   without disabling operation inbetween which will let the pin
   descriptor desc->mux_usecount increase monotonously.
2. The HW pin disable operation is not useful for any of the
   existing platforms.
   And this can be used to avoid the HW glitch after using the
   item #1 modification.

In the following case, the issue can be reproduced:
1. There is a driver that need to switch pin state dynamically,
   e.g. between "sleep" and "default" state
2. The pin setting configuration in a DTS node may be like this:

  component a {
	pinctrl-names = "default", "sleep";
	pinctrl-0 = <&a_grp_setting &c_grp_setting>;
	pinctrl-1 = <&b_grp_setting &c_grp_setting>;
  }

  The "c_grp_setting" config node is totally identical, maybe like
  following one:

  c_grp_setting: c_grp_setting {
	pinctrl-single,pins = ;
  }

3. When switching the pin state in the following official pinctrl
   sequence:
	pin = pinctrl_get();
	state = pinctrl_lookup_state(wanted_state);
	pinctrl_select_state(state);
	pinctrl_put();

Test Result:
1. The switch is completed as expected, that is: the device's
   pin configuration is changed according to the description in the
   "wanted_state" group setting
2. The "desc->mux_usecount" of the corresponding pins in "c_group"
   is increased without being decreased, because the "desc" is for
   each physical pin while the setting is for each setting node
   in the DTS.
   Thus, if the "c_grp_setting" in pinctrl-0 is not disabled ahead
   of enabling "c_grp_setting" in pinctrl-1, the desc->mux_usecount
   will keep increasing without any chance to be decreased.

According to the comments in the original code, only the setting,
in old state but not in new state, will be "disabled" (calling
pinmux_disable_setting), which is correct logic but not intact. We
still need consider case that the setting is in both old state
and new state. We can do this in the following two ways:

1. Avoid to "enable"(calling pinmux_enable_setting) the "same pin
   setting" repeatedly
2. "Disable"(calling pinmux_disable_setting) the "same pin setting",
   actually two setting instances, ahead of enabling them.

Analysis:
1. The solution #2 is better because it can avoid too much
   iteration.
2. If we disable all of the settings in the old state and one of
   the setting(s) exist in the new state, the pins mux function
   change may happen when some SoC vendors defined the
   "pinctrl-single,function-off"
   in their DTS file.
   old_setting => disabled_setting => new_setting.
3. In the pinmux framework, when a pin state is switched, the
   setting in the old state should be marked as "disabled".

Conclusion:
1. To Remove the HW disabling operation to above the glitch mentioned
   above.
2. Handle the issue mentioned above by disabling all of the settings
   in old state and then enable the all of the settings in new state.

Signed-off-by: Fan Wu 
Acked-by: Stephen Warren 
Acked-by: Patrice Chotard 
Acked-by: Heiko Stuebner 
Acked-by: Maxime Coquelin 
Signed-off-by: Linus Walleij

pinctrl: single: Clear pin interrupts enabled by bootloader

2014-04-23T13:56:56+00:00

Since we set up device wake-up interrupts as pinctrl-single
interrupts, we now must use the standard request_irq and
related functions to manage them.

If the pin interrupts are enabled for some pins at boot,
the wake-up events can show up as constantly pending
at least on omaps and will hang the system unless the related
device driver clears the event at the device.

To fix this, let's clear the interrupt flags during init,
and print out a warning so the board maintainers can update
their drivers to do proper request_irq for the driver specific
wake-up events.

Cc: Haojian Zhuang 
Cc: Linus Walleij 
Signed-off-by: Tony Lindgren 
Signed-off-by: Linus Walleij

pinctrl: single: add low power mode support

2014-02-10T09:13:08+00:00

For some silicons, the pin configuration register can control
the output of the pin when the pad including the pin enter
low power mode.
For example, the pin can be "Drive 1", "Drive 0", "Float" when
the pad including the pin enter low power mode.
It is very useful when you want to control the power leakeage
when the SOC enter low power mode, and can save more power for
the low power mode.

Signed-off-by: Chao Xie 
Signed-off-by: Linus Walleij

pinctrl: single: fix infinite loop caused by bad mask

2014-01-15T07:31:53+00:00

commit 4e7e8017a80e1 (pinctrl: pinctrl-single:
enhance to configure multiple pins of different modules) improved
support for pinctrl-single,bits option, but also caused a regression
in parsing badly configured mask data.

If the masks in DT data are not quite right,
pcs_parse_bits_in_pinctrl_entry() can end up in an infinite loop,
trashing memory at the same time.

Add a check to verify that each loop actually removes bits from the
'mask', so that the loop can eventually end.

Signed-off-by: Tomi Valkeinen 
Acked-by: Tony Lindgren 
Signed-off-by: Linus Walleij