linux.git/drivers/pinctrl/sirf, branch v3.17

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: sirf: fix a bad conflict resolution

2014-05-30T07:52:43+00:00

Commit 294d1351ff47726f0f110b88e816cbafe89512fb
"pinctrl: sirf: switch to using allocated state container"
caused a build conflict due to a bad conflict resolution
when cherry-picking the patch. Fix it up.

Cc: Barry Song 
Signed-off-by: Linus Walleij

pinctrl: sirf: switch to using allocated state container

2014-05-28T08:42:04+00:00

This rewrites the SIRF pinctrl driver to allocate a state container
for the GPIO chip, just as is done for the pin controller, and
use the gpiochip_add_pin_range() to add the range from the gpiochip
side rather than adding the range from the pinctrl side.

All resulting changes are done in order to pass around a state
container rather than refer to a static global object.

Acked-by: Barry Song 
Signed-off-by: Linus Walleij

pinctrl: sirf: fix typo for GPIO bank number

2014-05-27T13:25:05+00:00

The patch 7420d2d09b12: "pinctrl: sirf: switch driver to use gpiolib
irqchip helpers" from Apr 15, 2014, leads to the following static
checker warning:

      drivers/pinctrl/sirf/pinctrl-sirf.c:578 sirfsoc_gpio_handle_irq()
      warn: buffer overflow 'sgpio_chip.sgpio_bank' 5 <= 31

Cc: Dan Carpenter 
Signed-off-by: Barry Song 
Signed-off-by: Linus Walleij

pinctrl: sirf: switch driver to use gpiolib irqchip helpers

2014-04-23T20:02:54+00:00

This switches the SiRF pinctrl driver over to using the gpiolib
irqchip helpers simplifying some of the code.

Signed-off-by: Barry Song 
Signed-off-by: Linus Walleij

pinctrl: sirf: wrap all gpio banks into one gpio_chip

2014-04-23T20:01:31+00:00

all gpio banks are in one chip, that makes software clean in mapping
irq and gpio.

Signed-off-by: Barry Song 
Signed-off-by: Linus Walleij

pinctrl: sirf: rename inlined accessor

2014-04-23T20:01:17+00:00

The sirfsoc_irqchip_to_bank() is obviously misnamed, as it is
not converting an irqchip to a bank but converts a gpiochip
to a bank so rename it sirfsoc_gpiochip_to_bank().

Acked-by: Barry Song 
Signed-off-by: Linus Walleij

Merge tag 'gpio-v3.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio

2014-04-03T23:44:15+00:00

Pull bulk of gpio updates from Linus Walleij:
"A pretty big chunk of changes this time, but it has all been on
rotation in linux-next and had some testing. Of course there will be
some amount of fixes on top...

- Merged in a branch of irqchip changes from Thomas Gleixner: we need
to have new callbacks from the irqchip to determine if the GPIO
line will be eligible for IRQs, and this callback must be able to
say "no". After some thinking I got the branch from tglx and have
switched all current users over to use this.

- Based on tglx patches, we have added some generic irqchip helpers
in the gpiolib core. These will help centralize code when GPIO
drivers have simple chained/cascaded IRQs. Drivers will still
define their irqchip vtables, but the gpiolib core will take care
of irqdomain set-up, mapping from local offsets to Linux irqs, and
reserve resources by marking the GPIO lines for IRQs.

- Initially the PL061 and Nomadik GPIO/pin control drivers have been
switched over to use the new gpiochip-to-irqchip infrastructure
with more drivers expected for the next kernel cycle. The
factoring of just two drivers still makes it worth it so it is
already a win.

- A new driver for the Synopsys DesignWare APB GPIO block.

- Modify the DaVinci GPIO driver to be reusable also for the new TI
Keystone architecture.

- A new driver for the LSI ZEVIO SoCs.

- Delete the obsolte tnetv107x driver.

- Some incremental work on GPIO descriptors: have
gpiod_direction_output() use a logical level, respecting assertion
polarity through ACTIVE_LOW flags, adding gpiod_direction_output_raw()
for the case where you want to set that very value. Add
gpiochip_get_desc() to fetch a GPIO descriptor from a specific
offset on a certain chip inside driver code.

- Switch ACPI GPIO code over to using gpiochip_get_desc() and get rid
of gpio_to_desc().

- The ACPI GPIO event handling code has been reworked after
encountering an actual real life implementation.

- Support for ACPI GPIO operation regions.

- Generic GPIO chips can now be assigned labels/names from platform
data.

- We now clamp values returned from GPIO drivers to the boolean [0,1]
range.

- Some improved documentation on how to use the polarity flag was
added.

- a large slew of incremental driver updates and non-critical fixes.
Some targeted for stable"

* tag 'gpio-v3.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-gpio: (80 commits)
gpio: rcar: Add helper variable dev = &pdev->dev
gpio-lynxpoint: force gpio_get() to return "1" and "0" only
gpio: unmap gpio irqs properly
pch_gpio: set value before enabling output direction
gpio: moxart: Actually set output state in moxart_gpio_direction_output()
gpio: moxart: Avoid forward declaration
gpio: mxs: Allow for recursive enable_irq_wake() call
gpio: samsung: Add missing "break" statement
gpio: twl4030: Remove redundant assignment
gpio: dwapb: correct gpio-cells in binding document
gpio: iop: fix devm_ioremap_resource() return value checking
pinctrl: coh901: convert driver to use gpiolib irqchip
pinctrl: nomadik: convert driver to use gpiolib irqchip
gpio: pl061: convert driver to use gpiolib irqchip
gpio: add IRQ chip helpers in gpiolib
pinctrl: nomadik: factor in platform data container
pinctrl: nomadik: rename secondary to latent
gpio: Driver for SYSCON-based GPIOs
gpio: generic: Use platform_device_id->driver_data field for driver flags
pinctrl: coh901: move irq line locking to resource callbacks
...

Merge tag 'pinctrl-v3.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl

2014-04-01T20:10:49+00:00

Pull pin control bulk changes from Linus Walleij:
 "Pin control bulk changes for the v3.15 series, no new core
  functionality this time, just incremental driver updates:

   - A large refactoring of the MVEBU (Marvell) driver.

   - A large refactoring of the Tegra (nVidia) driver.

   - GPIO interrupt including soft edges support in the STi driver.

   - Misc updates to PFC (Renesas), AT91, ADI2 (Blackfin),
     pinctrl-single, sirf (CSR), msm (Qualcomm), Exynos (Samsung), sunxi
     (AllWinner), i.MX (Freescale), Baytrail"

* tag 'pinctrl-v3.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: (72 commits)
  pinctrl: tegra: add some missing Tegra114 entries
  pinctrl: tegra: fix some mistakes in Tegra124
  pinctrl: msm: fix up out-of-order merge conflict
  pinctrl: st: Fix error check for of_irq_to_resource usage
  pinctrl: tegra: consistency cleanup
  pinctrl: tegra: dynamically calculate function list of groups
  pinctrl: tegra: init Tegra20/30 at module_init time
  pinctrl: st: Use ARRAY_SIZE instead of raw value for number of delays
  pinctrl: st: add pinctrl support for the STiH407 SoC
  pinctrl: st: Enhance the controller to manage unavailable registers
  pinctrl: msm: Simplify msm_config_reg() and callers
  pinctrl: msm: Remove impossible WARN_ON()s
  pinctrl: msm: Replace lookup tables with math
  pinctrl: msm: Drop OF_IRQ dependency
  pinctrl: msm: Drop unused includes
  pinctrl: msm: Check for ngpios > MAX_NR_GPIO
  pinctrl: msm: Silence recursive lockdep warning
  pinctrl: mvebu: silence WARN to dev_warn
  pinctrl: msm: drop wake_irqs bitmap
  pinctrl-baytrail: add function mux checking in gpio pin request
  ...

gpio: switch drivers to use new callback

2014-03-18T08:28:30+00:00

This switches all GPIO and pin control drivers with irqchips
that were using .startup() and .shutdown() callbacks to lock
GPIO lines for IRQ usage over to using the .request_resources()
and .release_resources() callbacks just introduced into the
irqchip vtable.

Cc: Thomas Gleixner 
Cc: Jean-Jacques Hiblot 
Signed-off-by: Linus Walleij