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2019-05-21treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 18Thomas Gleixner1-14/+1
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program see the file copying if not write to the free software foundation 675 mass ave cambridge ma 02139 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 52 file(s). Signed-off-by: Thomas Gleixner <[email protected]> Reviewed-by: Jilayne Lovejoy <[email protected]> Reviewed-by: Steve Winslow <[email protected]> Reviewed-by: Kate Stewart <[email protected]> Reviewed-by: Allison Randal <[email protected]> Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Greg Kroah-Hartman <[email protected]>
2019-05-09pwm: Clear chip_data in pwm_put()Uwe Kleine-König1-0/+1
After a PWM is disposed by its user the per chip data becomes invalid. Clear the data in common code instead of the device drivers to get consistent behaviour. Before this patch only three of nine drivers cleaned up here. Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2019-03-20pwm: Fix deadlock warning when removing PWM devicePhong Hoang1-5/+5
This patch fixes deadlock warning if removing PWM device when CONFIG_PROVE_LOCKING is enabled. This issue can be reproceduced by the following steps on the R-Car H3 Salvator-X board if the backlight is disabled: # cd /sys/class/pwm/pwmchip0 # echo 0 > export # ls device export npwm power pwm0 subsystem uevent unexport # cd device/driver # ls bind e6e31000.pwm uevent unbind # echo e6e31000.pwm > unbind [ 87.659974] ====================================================== [ 87.666149] WARNING: possible circular locking dependency detected [ 87.672327] 5.0.0 #7 Not tainted [ 87.675549] ------------------------------------------------------ [ 87.681723] bash/2986 is trying to acquire lock: [ 87.686337] 000000005ea0e178 (kn->count#58){++++}, at: kernfs_remove_by_name_ns+0x50/0xa0 [ 87.694528] [ 87.694528] but task is already holding lock: [ 87.700353] 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c [ 87.707405] [ 87.707405] which lock already depends on the new lock. [ 87.707405] [ 87.715574] [ 87.715574] the existing dependency chain (in reverse order) is: [ 87.723048] [ 87.723048] -> #1 (pwm_lock){+.+.}: [ 87.728017] __mutex_lock+0x70/0x7e4 [ 87.732108] mutex_lock_nested+0x1c/0x24 [ 87.736547] pwm_request_from_chip.part.6+0x34/0x74 [ 87.741940] pwm_request_from_chip+0x20/0x40 [ 87.746725] export_store+0x6c/0x1f4 [ 87.750820] dev_attr_store+0x18/0x28 [ 87.754998] sysfs_kf_write+0x54/0x64 [ 87.759175] kernfs_fop_write+0xe4/0x1e8 [ 87.763615] __vfs_write+0x40/0x184 [ 87.767619] vfs_write+0xa8/0x19c [ 87.771448] ksys_write+0x58/0xbc [ 87.775278] __arm64_sys_write+0x18/0x20 [ 87.779721] el0_svc_common+0xd0/0x124 [ 87.783986] el0_svc_compat_handler+0x1c/0x24 [ 87.788858] el0_svc_compat+0x8/0x18 [ 87.792947] [ 87.792947] -> #0 (kn->count#58){++++}: [ 87.798260] lock_acquire+0xc4/0x22c [ 87.802353] __kernfs_remove+0x258/0x2c4 [ 87.806790] kernfs_remove_by_name_ns+0x50/0xa0 [ 87.811836] remove_files.isra.1+0x38/0x78 [ 87.816447] sysfs_remove_group+0x48/0x98 [ 87.820971] sysfs_remove_groups+0x34/0x4c [ 87.825583] device_remove_attrs+0x6c/0x7c [ 87.830197] device_del+0x11c/0x33c [ 87.834201] device_unregister+0x14/0x2c [ 87.838638] pwmchip_sysfs_unexport+0x40/0x4c [ 87.843509] pwmchip_remove+0xf4/0x13c [ 87.847773] rcar_pwm_remove+0x28/0x34 [ 87.852039] platform_drv_remove+0x24/0x64 [ 87.856651] device_release_driver_internal+0x18c/0x21c [ 87.862391] device_release_driver+0x14/0x1c [ 87.867175] unbind_store+0xe0/0x124 [ 87.871265] drv_attr_store+0x20/0x30 [ 87.875442] sysfs_kf_write+0x54/0x64 [ 87.879618] kernfs_fop_write+0xe4/0x1e8 [ 87.884055] __vfs_write+0x40/0x184 [ 87.888057] vfs_write+0xa8/0x19c [ 87.891887] ksys_write+0x58/0xbc [ 87.895716] __arm64_sys_write+0x18/0x20 [ 87.900154] el0_svc_common+0xd0/0x124 [ 87.904417] el0_svc_compat_handler+0x1c/0x24 [ 87.909289] el0_svc_compat+0x8/0x18 [ 87.913378] [ 87.913378] other info that might help us debug this: [ 87.913378] [ 87.921374] Possible unsafe locking scenario: [ 87.921374] [ 87.927286] CPU0 CPU1 [ 87.931808] ---- ---- [ 87.936331] lock(pwm_lock); [ 87.939293] lock(kn->count#58); [ 87.945120] lock(pwm_lock); [ 87.950599] lock(kn->count#58); [ 87.953908] [ 87.953908] *** DEADLOCK *** [ 87.953908] [ 87.959821] 4 locks held by bash/2986: [ 87.963563] #0: 00000000ace7bc30 (sb_writers#6){.+.+}, at: vfs_write+0x188/0x19c [ 87.971044] #1: 00000000287991b2 (&of->mutex){+.+.}, at: kernfs_fop_write+0xb4/0x1e8 [ 87.978872] #2: 00000000f739d016 (&dev->mutex){....}, at: device_release_driver_internal+0x40/0x21c [ 87.988001] #3: 000000006313b17c (pwm_lock){+.+.}, at: pwmchip_remove+0x28/0x13c [ 87.995481] [ 87.995481] stack backtrace: [ 87.999836] CPU: 0 PID: 2986 Comm: bash Not tainted 5.0.0 #7 [ 88.005489] Hardware name: Renesas Salvator-X board based on r8a7795 ES1.x (DT) [ 88.012791] Call trace: [ 88.015235] dump_backtrace+0x0/0x190 [ 88.018891] show_stack+0x14/0x1c [ 88.022204] dump_stack+0xb0/0xec [ 88.025514] print_circular_bug.isra.32+0x1d0/0x2e0 [ 88.030385] __lock_acquire+0x1318/0x1864 [ 88.034388] lock_acquire+0xc4/0x22c [ 88.037958] __kernfs_remove+0x258/0x2c4 [ 88.041874] kernfs_remove_by_name_ns+0x50/0xa0 [ 88.046398] remove_files.isra.1+0x38/0x78 [ 88.050487] sysfs_remove_group+0x48/0x98 [ 88.054490] sysfs_remove_groups+0x34/0x4c [ 88.058580] device_remove_attrs+0x6c/0x7c [ 88.062671] device_del+0x11c/0x33c [ 88.066154] device_unregister+0x14/0x2c [ 88.070070] pwmchip_sysfs_unexport+0x40/0x4c [ 88.074421] pwmchip_remove+0xf4/0x13c [ 88.078163] rcar_pwm_remove+0x28/0x34 [ 88.081906] platform_drv_remove+0x24/0x64 [ 88.085996] device_release_driver_internal+0x18c/0x21c [ 88.091215] device_release_driver+0x14/0x1c [ 88.095478] unbind_store+0xe0/0x124 [ 88.099048] drv_attr_store+0x20/0x30 [ 88.102704] sysfs_kf_write+0x54/0x64 [ 88.106359] kernfs_fop_write+0xe4/0x1e8 [ 88.110275] __vfs_write+0x40/0x184 [ 88.113757] vfs_write+0xa8/0x19c [ 88.117065] ksys_write+0x58/0xbc [ 88.120374] __arm64_sys_write+0x18/0x20 [ 88.124291] el0_svc_common+0xd0/0x124 [ 88.128034] el0_svc_compat_handler+0x1c/0x24 [ 88.132384] el0_svc_compat+0x8/0x18 The sysfs unexport in pwmchip_remove() is completely asymmetric to what we do in pwmchip_add_with_polarity() and commit 0733424c9ba9 ("pwm: Unexport children before chip removal") is a strong indication that this was wrong to begin with. We should just move pwmchip_sysfs_unexport() where it belongs, which is right after pwmchip_sysfs_unexport_children(). In that case, we do not need separate functions anymore either. We also really want to remove sysfs irrespective of whether or not the chip will be removed as a result of pwmchip_remove(). We can only assume that the driver will be gone after that, so we shouldn't leave any dangling sysfs files around. This warning disappears if we move pwmchip_sysfs_unexport() to the top of pwmchip_remove(), pwmchip_sysfs_unexport_children(). That way it is also outside of the pwm_lock section, which indeed doesn't seem to be needed. Moving the pwmchip_sysfs_export() call outside of that section also seems fine and it'd be perfectly symmetric with pwmchip_remove() again. So, this patch fixes them. Signed-off-by: Phong Hoang <[email protected]> [shimoda: revise the commit log and code] Fixes: 76abbdde2d95 ("pwm: Add sysfs interface") Fixes: 0733424c9ba9 ("pwm: Unexport children before chip removal") Signed-off-by: Yoshihiro Shimoda <[email protected]> Tested-by: Hoan Nguyen An <[email protected]> Reviewed-by: Geert Uytterhoeven <[email protected]> Reviewed-by: Simon Horman <[email protected]> Reviewed-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2019-01-10pwm: Drop per-chip dbg_show callbackUwe Kleine-König1-4/+1
This callback was introduced in commit 62099abf67a2 ("pwm: Add debugfs interface") in 2012 and up to now there is not a single user. So drop this unused code. Signed-off-by: Uwe Kleine-König <[email protected]> [[email protected]: remove kerneldoc for ->dbg_show()] Signed-off-by: Thierry Reding <[email protected]>
2019-01-10pwm: Don't use memcmp() to compare state variablesUwe Kleine-König1-1/+4
Given that struct pwm_state is sparse (at least on some platforms), variables of this type might represent the same state because all fields are pairwise identical but still memcmp() returns a difference because some of the unused bits are different. To prevent surprises compare member by member instead of the whole occupied memory. Signed-off-by: Uwe Kleine-König <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2017-07-06pwm: Silently error out on EPROBE_DEFERJerome Brunet1-1/+3
In of_pwm_get(), if we fail to get the PWM chip due to probe deferal, we shouldn't print an error message. Just be silent in this case. Signed-off-by: Jerome Brunet <[email protected]> Reviewed-by: Andreas Färber <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2017-01-30pwm: Try to load modules during pwm_get()Hans de Goede1-0/+14
Add a module name string to the pwm_lookup struct and if specified try to load the module using request_module() if pwmchip_find_by_name() is unable to find the PWM chip. This is a last resort to work around drivers that can't - and can't be made to - deal with deferred probe. Signed-off-by: Hans de Goede <[email protected]> [[email protected]: rename new macro, reword commit message] [[email protected]: add comment explaining use-case] Signed-off-by: Thierry Reding <[email protected]>
2017-01-30pwm: Don't hold pwm_lookup_lock longer than necessaryHans de Goede1-10/+8
There is no need to hold pwm_lookup_lock after we're done with looping over pwm_lookup_list, so release it earlier. Signed-off-by: Hans de Goede <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2017-01-30pwm: Make the PWM_POLARITY flag in DTB optionalLothar Wassmann1-10/+12
Change the PWM chip driver registration so that a chip driver that supports polarity inversion can still be used with DTBs that don't provide the polarity flag as part of the specifier. This is done to provide polarity inversion support for the pwm-imx driver without having to modify all existing DTS files. Signed-off-by: Lothar Wassmann <[email protected]> Signed-off-by: Bhuvanchandra DV <[email protected]> Suggested-by: Sascha Hauer <[email protected]> Signed-off-by: Lukasz Majewski <[email protected]> Reviewed-by: Boris Brezillon <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2017-01-30pwm: Print error messages with pr_err() instead of pr_debug()Lothar Wassmann1-2/+2
Make the messages that are printed in case of fatal errors actually visible to the user without having to recompile the driver with debugging enabled. Signed-off-by: Lothar Waßmann <[email protected]> Signed-off-by: Bhuvanchandra DV <[email protected]> Reviewed-by: Boris Brezillon <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2017-01-04pwm: Remove pwm_can_sleep()Thierry Reding1-12/+0
The last user of this function has been removed, so it is no longer needed. Signed-off-by: Thierry Reding <[email protected]>
2016-09-05pwm: Unexport children before chip removalDavid Hsu1-0/+2
Exported pwm channels aren't removed before the pwmchip and are leaked. This results in invalid sysfs files. This fix removes all exported pwm channels before chip removal. Signed-off-by: David Hsu <[email protected]> Fixes: 76abbdde2d95 ("pwm: Add sysfs interface") Signed-off-by: Thierry Reding <[email protected]>
2016-07-25Merge branch 'for-4.8/capture' into for-nextThierry Reding1-0/+27
2016-06-10pwm: Add PWM capture supportLee Jones1-0/+27
Supply a PWM capture callback op in order to pass back information obtained by running analysis on a PWM signal. This would normally (at least during testing) be called from the sysfs routines with a view to printing out PWM capture data which has been encoded into a string. Signed-off-by: Lee Jones <[email protected]> [[email protected]: make capture data unsigned int for symmetry] Signed-off-by: Thierry Reding <[email protected]>
2016-06-10pwm: Improve args checking in pwm_apply_state()Brian Norris1-1/+2
It seems like in the process of refactoring pwm_config() to utilize the newly-introduced pwm_apply_state() API, some args/bounds checking was dropped. In particular, I noted that we are now allowing invalid period selections, e.g.: # echo 1 > /sys/class/pwm/pwmchip0/export # cat /sys/class/pwm/pwmchip0/pwm1/period 100 # echo 101 > /sys/class/pwm/pwmchip0/pwm1/duty_cycle [... driver may or may not reject the value, or trigger some logic bug ...] It's better to see: # echo 1 > /sys/class/pwm/pwmchip0/export # cat /sys/class/pwm/pwmchip0/pwm1/period 100 # echo 101 > /sys/class/pwm/pwmchip0/pwm1/duty_cycle -bash: echo: write error: Invalid argument This patch reintroduces some bounds checks in both pwm_config() (for its signed parameters; we don't want to convert negative values into large unsigned values) and in pwm_apply_state() (which fix the above described behavior, as well as other potential API misuses). Fixes: 5ec803edcb70 ("pwm: Add core infrastructure to allow atomic updates") Signed-off-by: Brian Norris <[email protected]> Acked-by: Boris Brezillon <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2016-05-17Merge branch 'for-4.7/pwm-atomic' into for-nextThierry Reding1-90/+132
2016-05-17Merge branch 'for-4.7/pwm-args' into for-nextThierry Reding1-6/+20
2016-05-17pwm: Add information about polarity, duty cycle and period to debugfsHeiko Stübner1-0/+5
The PWM states make it possible to also output the polarity, duty cycle and period information in the debugfs summary output. This simplifies gathering information about PWMs without needing to walk through the sysfs attributes of every PWM. Signed-off-by: Heiko Stuebner <[email protected]> Signed-off-by: Boris Brezillon <[email protected]> [[email protected]: use more spaces in debugfs output] Signed-off-by: Thierry Reding <[email protected]>
2016-05-17pwm: Switch to the atomic APIBoris Brezillon1-1/+4
Replace legacy pwm_get/set_xxx() and pwm_config/enable/disable() calls by pwm_get/apply_state(). Signed-off-by: Boris Brezillon <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2016-05-17pwm: Add core infrastructure to allow atomic updatesBoris Brezillon1-68/+119
Add an ->apply() method to the pwm_ops struct to allow PWM drivers to implement atomic updates. This method is preferred over the ->enable(), ->disable() and ->config() methods if available. Add the pwm_apply_state() function to the PWM user API. Note that the pwm_apply_state() does not guarantee the atomicity of the update operation, it all depends on the availability and implementation of the ->apply() method. pwm_enable/disable/set_polarity/config() are now implemented as wrappers around the pwm_apply_state() function. pwm_adjust_config() is allowing smooth handover between the bootloader and the kernel. This function tries to adapt the current PWM state to the PWM arguments coming from a PWM lookup table or a DT definition without changing the duty_cycle/period proportion. Signed-off-by: Boris Brezillon <[email protected]> [[email protected]: fix a couple of typos] Signed-off-by: Thierry Reding <[email protected]>
2016-05-17pwm: Add hardware readout infrastructureBoris Brezillon1-0/+3
Add a ->get_state() function to the pwm_ops struct to let PWM drivers initialize the PWM state attached to a PWM device. Signed-off-by: Boris Brezillon <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2016-05-17pwm: Move the enabled/disabled info into pwm_stateBoris Brezillon1-4/+9
Prepare the transition to PWM atomic update by moving the enabled and disabled state into the pwm_state struct. This way we can easily update the whole PWM state by copying the new state in the ->state field. Signed-off-by: Boris Brezillon <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2016-05-17pwm: Introduce the pwm_state conceptBoris Brezillon1-4/+4
The PWM state, represented by its period, duty_cycle and polarity is currently directly stored in the PWM device. Declare a pwm_state structure embedding those field so that we can later use this struct to atomically update all the PWM parameters at once. All pwm_get_xxx() helpers are now implemented as wrappers around pwm_get_state(). Signed-off-by: Boris Brezillon <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2016-05-17pwm: Keep PWM state in sync with hardware stateBoris Brezillon1-14/+0
Before the introduction of pwm_args, the core was resetting the PWM period and polarity states to the reference values (those provided through the DT, a PWM lookup table or hardcoded in the driver). Now that all PWM users are correctly using pwm_args to configure their PWM device, we can safely remove the pwm_apply_args() call in pwm_get() and of_pwm_get(). We can also get rid of the pwm_set_period() call in pwm_apply_args(), because PWM users are now directly using pargs->period instead of pwm_get_period(). By doing that we avoid messing with the current PWM period. The only remaining bit in pwm_apply_args() is the initial polarity setting, and it should go away when all PWM users have been patched to use the atomic API (with this API the polarity will be set along with other PWM arguments when configuring the PWM). Signed-off-by: Boris Brezillon <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2016-05-17pwm: Get rid of pwm->lockBoris BREZILLON1-15/+4
PWM devices are not protected against concurrent accesses. The lock in struct pwm_device might let PWM users think it is, but it's actually only protecting the enabled state. Removing this lock should be fine as long as all PWM users are aware that accesses to the PWM device have to be serialized, which seems to be the case for all of them except the sysfs interface. Patch the sysfs code by adding a lock to the pwm_export struct and making sure it's taken for all relevant accesses to the exported PWM device. Signed-off-by: Boris Brezillon <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2016-05-17pwm: Fix pwm_apply_args() call sitesBoris Brezillon1-10/+17
pwm_apply_args() is supposed to initialize a PWM device according to the arguments provided by the DT or the PWM lookup, but this function was called inside pwm_device_request(), which in turn was called before the core had a chance to initialize the pwm->args fields. Fix that by calling pwm_apply_args directly in pwm_get() and of_pwm_get() after initializing pwm->args field. This commit also fixes an invalid pointer dereference introduced by commit e39c0df1be5a ("pwm: Introduce the pwm_args concept"). Signed-off-by: Boris Brezillon <[email protected]> Fixes: e39c0df1be5a ("pwm: Introduce the pwm_args concept") Signed-off-by: Thierry Reding <[email protected]>
2016-05-03pwm: Use kcalloc() instead of kzalloc()Thierry Reding1-1/+1
kcalloc() should be preferred for allocations of arrays over kzalloc() with multiplication. Signed-off-by: Thierry Reding <[email protected]>
2016-05-03pwm: Add missing newlineThierry Reding1-0/+1
checkpatch requires that declarations be separated from code by a blank line. Add one for readability and to silence the warning. Signed-off-by: Thierry Reding <[email protected]>
2016-05-03pwm: Introduce the pwm_args conceptBoris Brezillon1-7/+14
Currently the PWM core mixes the current PWM state with the per-platform reference config (specified through the PWM lookup table, DT definition or directly hardcoded in PWM drivers). Create a struct pwm_args to store this reference configuration, so that PWM users can differentiate between the current and reference configurations. Patch all places where pwm->args should be initialized. We keep the pwm_set_polarity/period() calls until all PWM users are patched to use pwm_args instead of pwm_get_period/polarity(). Signed-off-by: Boris Brezillon <[email protected]> [[email protected]: reword kerneldoc comments] Signed-off-by: Thierry Reding <[email protected]>
2016-01-21pwm: Mark all devices as "might sleep"Thierry Reding1-1/+1
Commit d1cd21427747 ("pwm: Set enable state properly on failed call to enable") introduced a mutex that is needed to protect internal state of PWM devices. Since that mutex is acquired in pwm_set_polarity() and in pwm_enable() and might potentially block, all PWM devices effectively become "might sleep". It's rather pointless to keep the .can_sleep field around, but given that there are external users let's postpone the removal for the next release cycle. Signed-off-by: Thierry Reding <[email protected]>
2015-11-10pwm: Return -ENODEV if no PWM lookup match is foundThierry Reding1-1/+3
When looking up a PWM using the lookup table, assume that all entries will have been added already, so failure to find a match means that no corresponding entry has been registered. This fixes an issue where -EPROBE_DEFER would be returned if the PWM lookup table is empty. After this fix, -EPROBE_DEFER is reserved for situations where no provider has yet registered for a matching entry. Signed-off-by: Thierry Reding <[email protected]>
2015-11-10pwm: Set enable state properly on failed call to enableJonathan Richardson1-7/+26
The pwm_enable() function didn't clear the enabled bit if a call to the driver's ->enable() callback returned an error. The result was that the state of the PWM core was wrong. Clearing the bit when enable returns an error ensures the state is properly set. Tested-by: Jonathan Richardson <[email protected]> Reviewed-by: Dmitry Torokhov <[email protected]> Signed-off-by: Jonathan Richardson <[email protected]> [[email protected]: add missing kerneldoc for the lock] Signed-off-by: Thierry Reding <[email protected]>
2015-08-17pwm: Clean up kerneldocThierry Reding1-6/+38
Clean up kerneldoc in preparation for including the PWM documentation in DocBook. Signed-off-by: Thierry Reding <[email protected]>
2015-08-17pwm: Remove useless whitespaceThierry Reding1-1/+0
Remove useless tabs used for padding in structure definitions as well as some blank lines. Signed-off-by: Thierry Reding <[email protected]>
2015-07-20pwm: Add the pwm_is_enabled() helperBoris Brezillon1-2/+2
Some PWM drivers are testing the PWMF_ENABLED flag. Create a helper function to hide the logic behind enabled test. This will allow us to smoothly move from the current approach to an atomic PWM update approach. Signed-off-by: Boris Brezillon <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2015-06-12pwm: Add pwmchip_add_with_polarity() APITim Kryger1-3/+20
Add a new function to register a PWM chip with channels that have their initial polarity as specified by an additional parameter. This benefits drivers of controllers that by default operate with inversed polarity by removing the need to modify the polarity during initialization. Signed-off-by: Tim Kryger <[email protected]> Signed-off-by: Jonathan Richardson <[email protected]> [[email protected]: export pwmchip_add_with_polarity()] Signed-off-by: Thierry Reding <[email protected]>
2015-05-06pwm: Add support to remove registered consumer lookup tablesShobhit Kumar1-0/+17
In case some drivers are unloading, they can remove lookup tables which they had registered during their load time to avoid redundant entries if loaded again. CC: Samuel Ortiz <[email protected]> Cc: Linus Walleij <[email protected]> Cc: Alexandre Courbot <[email protected]> Cc: Thierry Reding <[email protected]> Signed-off-by: Shobhit Kumar <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2015-04-23pwm: Remove __init initializer for pwm_add_table()Shobhit Kumar1-1/+1
For platforms that don't support DT, some early MFD modules can register lookup tables. Remove the __init annotation so that this works. This is similar to gpio_add_lookup_table() which allows late additions. CC: Samuel Ortiz <[email protected]> Cc: Linus Walleij <[email protected]> Cc: Alexandre Courbot <[email protected]> Cc: Thierry Reding <[email protected]> Signed-off-by: Shobhit Kumar <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2015-02-03pwm: Remove unnecessary check before of_node_put()Markus Elfring1-1/+1
The of_node_put() function tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2014-08-29pwm: Fix uninitialized warnings in pwm_get()Geert Uytterhoeven1-15/+14
With some versions of gcc (e.g. 4.1.2): drivers/pwm/core.c: In function ‘pwm_get’: drivers/pwm/core.c:610: warning: ‘polarity’ may be used uninitialized in this function drivers/pwm/core.c:609: warning: ‘period’ may be used uninitialized in this function While these are false positives, we can get rid of them by refactoring the code to store a pointer to the best match, as suggested before by Thierry Reding. This does require moving the mutex_unlock() down. Fixes: d717ea73e36dd565 ("pwm: Fix period and polarity in pwm_get() for non-perfect matches") Signed-off-by: Geert Uytterhoeven <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2014-08-25pwm: Fix possible ZERO_SIZE_PTR pointer dereferencing error.Xiubo Li1-1/+1
Since we cannot make sure the 'chip->npwm' will always be none zero here, and then if either equal to zero, the kzalloc() will return ZERO_SIZE_PTR, which equals to ((void *)16). So this patch fix this with just doing the zero check before calling kzalloc(). Signed-off-by: Xiubo Li <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2014-08-18pwm: Fix period and polarity in pwm_get() for non-perfect matchesGeert Uytterhoeven1-2/+6
If pwm_get() finds a look-up entry with a perfect match (both dev_id and con_id match), the loop is aborted, and "p" still points to the correct struct pwm_lookup. If only an entry with a matching dev_id or con_id is found, the loop terminates after traversing the whole list, and "p" now points to arbitrary memory, not part of the pwm_lookup list. Then pwm_set_period() and pwm_set_polarity() will set random values for period resp. polarity. To fix this, save period and polarity when finding a new best match, just like is done for chip (for the provider) and index. This fixes the LCD backlight on r8a7740/armadillo-legacy, which was fed period 0 and polarity -1068821144 instead of 33333 resp. 1. Fixes: 3796ce1d4d4b ("pwm: add period and polarity to struct pwm_lookup") Signed-off-by: Geert Uytterhoeven <[email protected]> Cc: [email protected] Signed-off-by: Thierry Reding <[email protected]>
2014-05-21pwm: add period and polarity to struct pwm_lookupAlexandre Belloni1-1/+7
Add period and polarity members to struct pwm_lookup so that platforms using the lookup table can be treated the same way as those using the device tree. Signed-off-by: Alexandre Belloni <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2013-12-20pwm: use seq_puts() instead of seq_printf()Jingoo Han1-3/+3
For a constant format without additional arguments, use seq_puts() instead of seq_printf(). Also, the following checkpatch warning is fixed. WARNING: Prefer seq_puts to seq_printf Signed-off-by: Jingoo Han <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2013-09-03pwm: Use the DT macro directly when parsing PWM DT flagsLaurent Pinchart1-4/+3
Don't redefine a PWM_SPEC_POLARITY macro with a value identical to PWM_POLARITY_INVERTED, use the PWM DT macro directly. Signed-off-by: Laurent Pinchart <[email protected]> Reviewed-by: Stephen Warren <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2013-06-21pwm: Add sysfs interfaceH Hartley Sweeten1-2/+23
Add a simple sysfs interface to the generic PWM framework. /sys/class/pwm/ `-- pwmchipN/ for each PWM chip |-- export (w/o) ask the kernel to export a PWM channel |-- npwm (r/o) number of PWM channels in this PWM chip |-- pwmX/ for each exported PWM channel | |-- duty_cycle (r/w) duty cycle (in nanoseconds) | |-- enable (r/w) enable/disable PWM | |-- period (r/w) period (in nanoseconds) | `-- polarity (r/w) polarity of PWM (normal/inversed) `-- unexport (w/o) return a PWM channel to the kernel Based on work by Lars Poeschel. Signed-off-by: H Hartley Sweeten <[email protected]> Cc: Thierry Reding <[email protected]> Cc: Lars Poeschel <[email protected]> Cc: Ryan Mallon <[email protected]> Cc: Rob Landley <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2013-06-10pwm: devm: alloc correct pointer sizeWolfram Sang1-2/+2
The allocated object should be the size of what the pointer is pointing to and not the size of the pointer itself. Signed-off-by: Wolfram Sang <[email protected]> Reviewed-by: Andy Shevchenko <[email protected]> Signed-off-by: Thierry Reding <[email protected]>
2013-02-26Merge tag 'for-3.9-rc1' of git://gitorious.org/linux-pwm/linux-pwmLinus Torvalds1-0/+14
Pull PWM changes from Thierry Reding: "A new driver has been added to support the PWM mode of the timer counter blocks found on Atmel AT91 SoCs. The VT8500 driver now supports changing the PWM signal polarity and the TI drivers (EHRPWM and ECAP) gained suspend and resume functionality. User drivers can now query the core for whether access to a PWM device will sleep (if the PWM chip is on a slow bus such as I2C or SPI). The pwm-backlight driver now handles the backlight BL_CORE_FBBLANK state in addition to the FB layer's blanking states. To round things off, a few fixes and cleanups are also included" * tag 'for-3.9-rc1' of git://gitorious.org/linux-pwm/linux-pwm: pwm: twl: Use to_twl() instead of container_of() pwm: tegra: assume CONFIG_OF pwm_backlight: Validate dft_brightness in main probe function pwm: Export pwm_{set,get}_chip_data() pwm: Make Kconfig entries more consistent pwm: Add can_sleep property to drivers pwm: Add pwm_can_sleep() as exported API to users pwm-backlight: handle BL_CORE_FBBLANK state pwm: pwm-tiecap: Low power sleep support pwm: pwm-tiehrpwm: Low power sleep support pwm: pwm-tiehrpwm: Update the clock handling of pwm-tiehrpwm driver pwm: vt8500: Add polarity support pwm: vt8500: Register write busy test performed incorrectly pwm: atmel: add Timer Counter Block PWM driver
2013-02-01pwm: Add devm_of_pwm_get() as exported API for usersPeter Ujfalusi1-0/+30
When booted with DT users can use devm version of of_pwm_get() to benefit from automatic resource release. Signed-off-by: Peter Ujfalusi <[email protected]> Acked-by: Thierry Reding <[email protected]> Signed-off-by: Bryan Wu <[email protected]>
2013-02-01pwm: core: Rename of_pwm_request() to of_pwm_get() and export itPeter Ujfalusi1-4/+4
Allow client driver to use of_pwm_get() to get the PWM they need. This is needed for drivers which handle more than one PWM separately, like leds-pwm driver, which have: pwmleds { compatible = "pwm-leds"; kpad { label = "omap4::keypad"; pwms = <&twl_pwm 0 7812500>; max-brightness = <127>; }; charging { label = "omap4:green:chrg"; pwms = <&twl_pwmled 0 7812500>; max-brightness = <255>; }; }; in the dts files. Signed-off-by: Peter Ujfalusi <[email protected]> Acked-by: Thierry Reding <[email protected]> Signed-off-by: Bryan Wu <[email protected]>
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