linux/drivers/pinctrl/core.c, branch v3.4.30

pinctrl: implement pinctrl_check_ops

2012-04-11T07:31:02Z

Most code assumes that the pinctrl ops are present. Validate this when registering a pinctrl driver. Remove the one place in the code that was checking whether one of these non-optional ops was present. Signed-off-by: Stephen Warren Signed-off-by: Linus Walleij

pinctrl: enhance mapping table to support pin config operations

2012-03-05T10:25:11Z

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: Stephen Warren Acked-by: Dong Aisheng Signed-off-by: Linus Walleij

pinctrl: API changes to support multiple states per device

2012-03-05T10:22:59Z

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: Stephen Warren Acked-by: Dong Aisheng Signed-off-by: Linus Walleij

pinctrl: refactor struct pinctrl handling in core.c vs pinmux.c

2012-03-05T10:20:50Z

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: Stephen Warren Acked-by: Linus Walleij Acked-by: Dong Aisheng Signed-off-by: Linus Walleij

pinctrl: fix and simplify locking

2012-03-05T10:19:49Z

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: Stephen Warren Signed-off-by: Linus Walleij

pinctrl: assume map table entries can't have a NULL name field

2012-03-02T15:20:54Z

pinctrl_register_mappings() already requires that every mapping table entry have a non-NULL name field. Logically, this makes sense too; drivers should always request a specific named state so they know what they're getting. Relying on getting the first mentioned state in the mapping table is error-prone, and a nasty special case to implement, given that a given the mapping table may define multiple states for a device. Remove a small part of the documentation that talked about optionally requesting a specific state; it's mandatory now. Signed-off-by: Stephen Warren Acked-by: Dong Aisheng Signed-off-by: Linus Walleij

pinctrl: introduce PINCTRL_STATE_DEFAULT, define hogs as that state

2012-03-02T15:18:24Z

This provides a single centralized name for the default state. Update PIN_MAP_* macros to use this state name, instead of requiring the user to pass a state name in. With this change, hog entries in the mapping table are defined as those with state name PINCTRL_STATE_DEFAULT, i.e. all entries have the same name. This interacts badly with the nested iteration over mapping table entries in pinctrl_hog_maps() and pinctrl_hog_map() which would now attempt to claim each hog mapping table entry multiple times. Replacing the custom hog code with a simple pinctrl_get()/pinctrl_enable(). Update documentation and mapping tables to use this. Signed-off-by: Stephen Warren Acked-by: Dong Aisheng Signed-off-by: Linus Walleij

pinctrl: move pinctrl-maps debugfs file to top-level

2012-02-29T18:10:56Z

The debugfs file pinctrl-maps is a system-wide file, not specific to any pin controller, so place it in the top-level directory. Also, move the code implementing the file to keep the order of all the functions matching the order they're created in pinctrl_init_*debugfs(). The only non-obvious change here is no private data is passed to debugfs_create_file() or single_open(). Signed-off-by: Stephen Warren Acked-by: Dong Aisheng Signed-off-by: Linus Walleij

pinctrl: remove pin and hogs locks from struct pinctrl_dev

2012-02-24T05:30:50Z

struct pinctrl_dev's pin_desc_tree_lock and pinctrl_hogs_lock aren't useful; the data they protect is read-only except when registering or unregistering a pinctrl_dev, and at those times, it doesn't make sense to protect one part of the structure independently from the rest. Move pinctrl_init_device_debugfs() to the end of pinctrl_register() so that debugfs can't access the struct pinctrl_dev until it's fully initialized, i.e. after the hogs are set up. Signed-off-by: Stephen Warren Signed-off-by: Linus Walleij

pinctrl: allocate sizeof(*p) instead of sizeof(struct foo)

2012-02-24T05:28:56Z

This hopefully makes it harder to take the sizeof the wrong type. Signed-off-by: Stephen Warren Acked-by: Dong Aisheng Signed-off-by: Linus Walleij