1. 06 Mar, 2012 3 commits
  2. 05 Mar, 2012 6 commits
    • Stephen Warren's avatar
      pinctrl: Show selected function and group in pinmux-pins debugfs · ba110d90
      Stephen Warren authored
      Until recently, the pinctrl pinmux-pins debugfs file displayed the
      selected function for each owned pin. This feature was removed during
      restructing in support of recent API rework. This change restoreds this
      feature, and also displays the group that the function was selected on,
      in case a pin is a member of multiple groups.
      
      Based on work by: Linus Walleij <linus.walleij@linaro.org>
      Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
      Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
      ba110d90
    • Stephen Warren's avatar
      pinctrl: enhance mapping table to support pin config operations · 1e2082b5
      Stephen Warren authored
      The pinctrl mapping table can now contain entries to:
      * Set the mux function of a pin group
      * Apply a set of pin config options to a pin or a group
      
      This allows pinctrl_select_state() to apply pin configs settings as well
      as mux settings.
      
      v3: Fix find_pinctrl() to iterate over the correct list.
         s/_MUX_CONFIGS_/_CONFIGS_/ in mapping table macros.
         Fix documentation to use correct mapping table macro.
      v2: Added numerous extra PIN_MAP_*() special-case macros.
         Fixed kerneldoc typo. Delete pinctrl_get_pin_id() and
         replace it with pin_get_from_name(). Various minor fixes.
         Updates due to rebase.
      Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
      Acked-by: default avatarDong Aisheng <dong.aisheng@linaro.org>
      Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
      1e2082b5
    • Stephen Warren's avatar
      pinctrl: API changes to support multiple states per device · 6e5e959d
      Stephen Warren authored
      The API model is changed from:
      
      p = pinctrl_get(dev, "state1");
      pinctrl_enable(p);
      ...
      pinctrl_disable(p);
      pinctrl_put(p);
      p = pinctrl_get(dev, "state2");
      pinctrl_enable(p);
      ...
      pinctrl_disable(p);
      pinctrl_put(p);
      
      to this:
      
      p = pinctrl_get(dev);
      s1 = pinctrl_lookup_state(p, "state1");
      s2 = pinctrl_lookup_state(p, "state2");
      pinctrl_select_state(p, s1);
      ...
      pinctrl_select_state(p, s2);
      ...
      pinctrl_put(p);
      
      This allows devices to directly transition between states without
      disabling the pin controller programming and put()/get()ing the
      configuration data each time. This model will also better suit pinconf
      programming, which doesn't have a concept of "disable".
      
      The special-case hogging feature of pin controllers is re-written to use
      the regular APIs instead of special-case code. Hence, the pinmux-hogs
      debugfs file is removed; see the top-level pinctrl-handles files for
      equivalent data.
      Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
      Acked-by: default avatarDong Aisheng <dong.aisheng@linaro.org>
      Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
      6e5e959d
    • Stephen Warren's avatar
      pinctrl: add usecount to pins for muxing · 0e3db173
      Stephen Warren authored
      Multiple mapping table entries could reference the same pin, and hence
      "own" it. This would be unusual now that pinctrl_get() represents a single
      state for a client device, but in the future when it represents all known
      states for a device, this is quite likely. Implement reference counting
      for pin ownership to handle this.
      Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
      Acked-by: default avatarDong Aisheng <dong.aisheng@linaro.org>
      Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
      0e3db173
    • Stephen Warren's avatar
      pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c · 7ecdb16f
      Stephen Warren authored
      This change separates two aspects of struct pinctrl:
      
      a) The data representation of the parsed mapping table, into:
      
         1) The top-level struct pinctrl object, a single entity returned
            by pinctrl_get().
      
         2) The parsed version of each mapping table entry, struct
            pinctrl_setting, of which there is one per mapping table entry.
      
      b) The code that handles this; the code for (1) above is in core.c, and
         the code to parse/execute each entry in (2) above is in pinmux.c, while
         the iteration over multiple settings is lifted to core.c.
      
      This will allow the following future changes:
      
      1) pinctrl_get() API rework, so that struct pinctrl represents all states
         for the device, and the device can select between them without calling
         put()/get() again.
      
      2) To support that, a struct pinctrl_state object will be inserted into
         the data model between the struct pinctrl and struct pinctrl_setting.
      
      3) The mapping table will be extended to allow specification of pin config
         settings too. To support this, struct pinctrl_setting will be enhanced
         to store either mux settings or config settings, and functions will be
         added to pinconf.c to parse/execute pin configuration settings.
      Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
      Acked-by: default avatarLinus Walleij <linus.walleij@linaro.org>
      Acked-by: default avatarDong Aisheng <dong.aisheng@linaro.org>
      Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
      7ecdb16f
    • Stephen Warren's avatar
      pinctrl: fix and simplify locking · 57b676f9
      Stephen Warren authored
      There are many problems with the current pinctrl locking:
      
      struct pinctrl_dev's gpio_ranges_lock isn't effective;
      pinctrl_match_gpio_range() only holds this lock while searching for a gpio
      range, but the found range is return and manipulated after releading the
      lock. This could allow pinctrl_remove_gpio_range() for that range while it
      is in use, and the caller may very well delete the range after removing it,
      causing pinctrl code to touch the now-free range object.
      
      Solving this requires the introduction of a higher-level lock, at least
      a lock per pin controller, which both gpio range registration and
      pinctrl_get()/put() will acquire.
      
      There is missing locking on HW programming; pin controllers may pack the
      configuration for different pins/groups/config options/... into one
      register, and hence have to read-modify-write the register. This needs to
      be protected, but currently isn't. Related, a future change will add a
      "complete" op to the pin controller drivers, the idea being that each
      state's programming will be programmed into the pinctrl driver followed
      by the "complete" call, which may e.g. flush a register cache to HW. For
      this to work, it must not be possible to interleave the pinctrl driver
      calls for different devices.
      
      As above, solving this requires the introduction of a higher-level lock,
      at least a lock per pin controller, which will be held for the duration
      of any pinctrl_enable()/disable() call.
      
      However, each pinctrl mapping table entry may affect a different pin
      controller if necessary. Hence, with a per-pin-controller lock, almost
      any pinctrl API may need to acquire multiple locks, one per controller.
      To avoid deadlock, these would need to be acquired in the same order in
      all cases. This is extremely difficult to implement in the case of
      pinctrl_get(), which doesn't know which pin controllers to lock until it
      has parsed the entire mapping table, since it contains somewhat arbitrary
      data.
      
      The simplest solution here is to introduce a single lock that covers all
      pin controllers at once. This will be acquired by all pinctrl APIs.
      
      This then makes struct pinctrl's mutex irrelevant, since that single lock
      will always be held whenever this mutex is currently held.
      Signed-off-by: default avatarStephen Warren <swarren@nvidia.com>
      Signed-off-by: default avatarLinus Walleij <linus.walleij@linaro.org>
      57b676f9
  3. 02 Mar, 2012 4 commits
  4. 29 Feb, 2012 3 commits
  5. 24 Feb, 2012 4 commits
  6. 22 Feb, 2012 14 commits
  7. 10 Feb, 2012 4 commits
  8. 01 Feb, 2012 2 commits