kernel.git/drivers/pinctrl/pinctrl-tegra.c, branch linux-4.0.y

pinctrl: clean up after enable refactoring

2014-09-04T08:05:07Z

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: avoid duplicated calling enable_pinmux_setting for a pin

2014-07-11T12:08:26Z

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: tegra: print better error messages

2014-04-22T14:53:43Z

When an attempt is made to configure an unsupported option on a pin, print the DT property name of that option, so it's easier to debug what the problem is. Signed-off-by: Stephen Warren Acked-by: Laxman Dewangan Signed-off-by: Linus Walleij

pinctrl: tegra: remove fsafe from data tables

2014-04-22T14:50:24Z

The fsafe value in the pingroup data tables is only used to implement tegra_pinctrl_disable(). The only reason this function is called is when dynamically switching between pinmux states, i.e. when disabling the old state before programming the new state. It's simpler to have the new target state define the expected value of each pin (and all current DTs do that). This also gives more flexibility, since it allows individual boards explicit control over the "inactive" mux function for each pin, rather than requiring it to be an SoC-specific value. Assuming this, we can get rid of the fsafe value from the driver completely, thus saving some more space in the driver tables. While re-writing the content of tegra124_pingroups[], fix the indentation to use a TAB instead of spaces. Signed-off-by: Stephen Warren Acked-by: Laxman Dewangan Signed-off-by: Linus Walleij

pinctrl: tegra: remove redundant data table fields

2014-04-22T14:48:39Z

Any SoC which supports the einput, odrain, lock, ioreset, or rcv_sel options has the relevant HW register fields in the same register as the mux function selection. Similarly, the drvtype option is always in the drive register, if it is supported at all. Hence, we don't need to have struct *_reg fields in the pin group table to define which register and bank to use for those options. Delete this to save space in the driver's data tables. However, many of those options are not supported on all SoCs, or not supported on some pingroups. We need a way to detect when they are supported. Previously, this was indicated by setting the struct *_reg field to -1. With the struct *_reg fields removed, we use the struct *_bit fields for this purpose instead. The struct *_bit fields need to be expanded from 5 to 6 bits in order to store a value outside the valid HW bit range of 0..31. Even without removing the struct *_reg fields, we still need to add code to validate the struct *_bit fields, since some struct *_bit fields were already being set to -1, without an option-specific struct *_reg field to "guard" them. In other words, before this change, the pinmux driver might allow some unsupported options to be written to HW. Signed-off-by: Stephen Warren Signed-off-by: Linus Walleij

pinctrl: tegra: dynamically calculate function list of groups

2014-03-12T14:23:41Z

The per-SoC data structures for Tegra pinctrl stored some information in a redundant way. Specifically, the list of groups that each function could be muxed onto was stored once explicitly, and also as part of the definition of each group. Eliminate this redundancy, and calculate each function's list of valid groups at pinctrl probe time. This removes thousands of lines of code from the pinctrl driver and ~16K from the vmlinux binary size, and adds only about 500uS to the boot process (on Tegra30; newer SoCs will likely be faster still). Signed-off-by: Stephen Warren Signed-off-by: Linus Walleij

pinctrl: tegra: return correct error type

2014-02-06T13:21:19Z

When memory allocation failed, drive should return error as ENOMEM. Signed-off-by: Laxman Dewangan Acked-by: Stephen Warren Signed-off-by: Linus Walleij

pinctrl: Pass all configs to driver on pin_config_set()

2013-08-28T11:34:41Z

When setting pin configuration in the pinctrl framework, pin_config_set() or pin_config_group_set() is called in a loop to set one configuration at a time for the specified pin or group. This patch 1) removes the loop and 2) changes the API to pass the whole pin config array to the driver. It is now up to the driver to loop through the configs. This allows the driver to potentially combine configs and reduce the number of writes to pin config registers. All c files changed have been build-tested to verify the change compiles and that the corresponding .o is successfully generated. Signed-off-by: Sherman Yin Reviewed-by: Christian Daudt Reviewed-by: Matt Porter Tested-by: Stephen Warren Acked-by: Laurent Pinchart Signed-off-by: Linus Walleij

pinctrl: tegra: Convert to devm_ioremap_resource

2013-08-28T11:34:18Z

Using the new devm_ioremap_resource() we can greatly simplify resource handling. Signed-off-by: Axel Lin Acked-by: Stephen Warren Signed-off-by: Linus Walleij

pinctrl: tegra: use pinctrl-utils APIs for mapping

2013-08-23T06:56:32Z

Pin control utility functions provides the function for creating map lists. In place of implementing APIs locally in Tegra pin control driver for creating map lists, use the utility functions. This reduces the code size and avoid duplication. Changes from V1: - Rebased change on top of V1. - Use pinctrl_utils_dt_free_map Signed-off-by: Laxman Dewangan Acked-by: Stephen Warren Signed-off-by: Linus Walleij