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path: root/drivers/pwm
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2016-05-25Merge tag 'pwm/for-4.7-rc1' of ↵Linus Torvalds7-106/+199
git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm Pull pwm updates from Thierry Reding: "This set of changes introduces an atomic API to the PWM subsystem. This is influenced by the DRM atomic API that was introduced a while back, though it is obviously a lot simpler. The fundamental idea remains the same, though: drivers provide a single callback to implement the atomic configuration of a PWM channel. As a side-effect the PWM subsystem gains the ability for initial state retrieval, so that the logical state mirrors that of the hardware. Many use-cases don't care about this, but for others it is essential. These new features require changes in all users, which these patches take care of. The core is transitioned to use the atomic callback if available and provides a fallback mechanism for other drivers. Changes to transition users and drivers to the atomic API are postponed to v4.8" * tag 'pwm/for-4.7-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (30 commits) pwm: Add information about polarity, duty cycle and period to debugfs pwm: Switch to the atomic API pwm: Update documentation pwm: Add core infrastructure to allow atomic updates pwm: Add hardware readout infrastructure pwm: Move the enabled/disabled info into pwm_state pwm: Introduce the pwm_state concept pwm: Keep PWM state in sync with hardware state ARM: Explicitly apply PWM config extracted from pwm_args drm: i915: Explicitly apply PWM config extracted from pwm_args input: misc: pwm-beeper: Explicitly apply PWM config extracted from pwm_args input: misc: max8997: Explicitly apply PWM config extracted from pwm_args backlight: lm3630a: explicitly apply PWM config extracted from pwm_args backlight: lp855x: Explicitly apply PWM config extracted from pwm_args backlight: lp8788: Explicitly apply PWM config extracted from pwm_args backlight: pwm_bl: Use pwm_get_args() where appropriate fbdev: ssd1307fb: Use pwm_get_args() where appropriate regulator: pwm: Use pwm_get_args() where appropriate leds: pwm: Use pwm_get_args() where appropriate input: misc: max77693: Use pwm_get_args() where appropriate ...
2016-05-17Merge branch 'for-4.7/pwm-atomic' into for-nextThierry Reding7-109/+194
2016-05-17Merge branch 'for-4.7/pwm-args' into for-nextThierry Reding3-8/+22
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 <heiko@sntech.de> Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> [thierry.reding@gmail.com: use more spaces in debugfs output] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17pwm: Switch to the atomic APIBoris Brezillon2-12/+41
Replace legacy pwm_get/set_xxx() and pwm_config/enable/disable() calls by pwm_get/apply_state(). Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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 <boris.brezillon@free-electrons.com> [thierry.reding@gmail.com: fix a couple of typos] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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 <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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 <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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 <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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 <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17pwm: Use pwm_get/set_xxx() helpers where appropriateBoris Brezillon4-4/+5
Use pwm_get/set_xxx() helpers instead of directly accessing the pwm->xxx field. Doing that will ease adaptation of the PWM framework to support atomic update. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17pwm: Get rid of pwm->lockBoris BREZILLON2-19/+24
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 <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-17pwm: rcar: Make use of pwm_is_enabled()Boris BREZILLON1-1/+1
Commit 5c31252c4a86 ("pwm: Add the pwm_is_enabled() helper") introduced a new function to test whether a PWM device is enabled or not without manipulating PWM internal fields. Hiding this is necessary if we want to smoothly move to the atomic PWM config approach without impacting PWM drivers. Fix this driver to use pwm_is_enabled() instead of directly accessing the ->flags field. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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 <boris.brezillon@free-electrons.com> Fixes: e39c0df1be5a ("pwm: Introduce the pwm_args concept") Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-05-13Merge remote-tracking branches 'regulator/topic/pwm', ↵Mark Brown3-9/+16
'regulator/topic/qcom-spmi', 'regulator/topic/rk808' and 'regulator/topic/s2mps11' into regulator-next
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 <thierry.reding@gmail.com>
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 <thierry.reding@gmail.com>
2016-05-03pwm: Introduce the pwm_args conceptBoris Brezillon3-9/+16
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 <boris.brezillon@free-electrons.com> [thierry.reding@gmail.com: reword kerneldoc comments] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-04-14pwm: fsl-ftm: Use flat regmap cacheStefan Agner1-1/+1
Use flat regmap cache to avoid lockdep warning at probe: [ 0.697285] WARNING: CPU: 0 PID: 1 at kernel/locking/lockdep.c:2755 lockdep_trace_alloc+0x15c/0x160() [ 0.697449] DEBUG_LOCKS_WARN_ON(irqs_disabled_flags(flags)) The RB-tree regmap cache needs to allocate new space on first writes. However, allocations in an atomic context (e.g. when a spinlock is held) are not allowed. The function regmap_write calls map->lock, which acquires a spinlock in the fast_io case. Since the pwm-fsl-ftm driver uses MMIO, the regmap bus of type regmap_mmio is being used which has fast_io set to true. The MMIO space of the pwm-fsl-ftm driver is reasonable condense, hence using the much faster flat regmap cache is anyway the better choice. Signed-off-by: Stefan Agner <stefan@agner.ch> Cc: Mark Brown <broonie@kernel.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-03-23pwm: omap-dmtimer: Add debug message for effective period and duty cycleDavid Rivshin1-1/+8
After going through the math and constraints checking to compute load and match values, it is helpful to know what the resultant period and duty cycle are. Signed-off-by: David Rivshin <drivshin@allworx.com> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-03-23pwm: omap-dmtimer: Round load and match values rather than truncateDavid Rivshin1-5/+1
When converting period and duty_cycle from nanoseconds to fclk cycles, the error introduced by the integer division can be appreciable, especially in the case of slow fclk or short period. Use DIV_ROUND_CLOSEST_ULL() so that the error is kept to +/- 0.5 clock cycles. Fixes: 6604c6556db9 ("pwm: Add PWM driver for OMAP using dual-mode timers") Signed-off-by: David Rivshin <drivshin@allworx.com> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-03-23pwm: omap-dmtimer: Add sanity checking for load and match valuesDavid Rivshin1-4/+30
Add sanity checking to ensure that we do not program load or match values that are out of range if a user requests period or duty_cycle values which are not achievable. The match value cannot be less than the load value (but can be equal), and neither can be 0xffffffff. This means that there must be at least one fclk cycle between load and match, and another between match and overflow. Fixes: 6604c6556db9 ("pwm: Add PWM driver for OMAP using dual-mode timers") Signed-off-by: David Rivshin <drivshin@allworx.com> Acked-by: Neil Armstrong <narmstrong@baylibre.com> [thierry.reding@gmail.com: minor coding style cleanups] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-03-23pwm: omap-dmtimer: Fix inaccurate period and duty cycle calculationsDavid Rivshin1-7/+20
Fix the calculation of load_value and match_value. Currently they are slightly too low, which produces a noticeably wrong PWM rate with sufficiently short periods (i.e. when 1/period approaches clk_rate/2). Example: clk_rate=32768Hz, period=122070ns, duty_cycle=61035ns (8192Hz/50% PWM) Correct values: load = 0xfffffffc, match = 0xfffffffd Current values: load = 0xfffffffa, match = 0xfffffffc effective PWM: period=183105ns, duty_cycle=91553ns (5461Hz/50% PWM) Fixes: 6604c6556db9 ("pwm: Add PWM driver for OMAP using dual-mode timers") Signed-off-by: David Rivshin <drivshin@allworx.com> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Tested-by: Adam Ford <aford173@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-03-23pwm: brcmstb: Fix check of devm_ioremap_resource() return codeVladimir Zapolskiy1-2/+2
The change fixes potential oops while accessing iomem on invalid address if devm_ioremap_resource() fails due to some reason. The devm_ioremap_resource() function returns ERR_PTR() and never returns NULL, which makes useless a following check for NULL. Signed-off-by: Vladimir Zapolskiy <vz@mleia.com> Fixes: 3a9f5957020f ("pwm: Add Broadcom BCM7038 PWM controller support") Acked-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-03-23pwm: rcar: Depend on ARCH_RENESAS instead of ARCH_SHMOBILESimon Horman1-1/+1
This is part of an ongoing process to migrate from ARCH_SHMOBILE to ARCH_RENESAS the motivation for which being that RENESAS seems to be a more appropriate name than SHMOBILE for the majority of Renesas ARM based SoCs. Signed-off-by: Simon Horman <horms+renesas@verge.net.au> Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-03-23pwm: lpc18xx-sct: Test clock rate to avoid division by 0Wolfram Sang1-0/+5
The clk API may return 0 on clk_get_rate(), so we should check the result before using it as a divisor. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Acked-by: Joachim Eastwood <manabian@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-03-23pwm: img: Test clock rate to avoid division by 0Wolfram Sang1-0/+5
The clk API may return 0 on clk_get_rate(), so we should check the result before using it as a divisor. Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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 <thierry.reding@gmail.com>
2016-01-04pwm: omap-dmtimer: Potential NULL dereference on errorDan Carpenter1-1/+1
"omap" is NULL so we can't dereference it. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-01-04pwm: add HAS_IOMEM dependency to PWM_FSL_FTMVegard Nossum1-0/+1
Ran into this on UML: drivers/built-in.o: In function `fsl_pwm_probe': linux/drivers/pwm/pwm-fsl-ftm.c:436: undefined reference to `devm_ioremap_resource' collect2: error: ld returned 1 exit status devm_ioremap_resource() is defined only when HAS_IOMEM is selected. Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: Xiubo Li <Li.Xiubo@freescale.com> Cc: Alison Wang <b18965@freescale.com> Cc: Jingchang Lu <b35083@freescale.com> Cc: Sascha Hauer <s.hauer@pengutronix.de> Cc: Yuan Yao <yao.yuan@freescale.com> Cc: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: Add PWM driver for OMAP using dual-mode timersNeil Armstrong3-0/+337
Adds support for using a OMAP dual-mode timer with PWM capability as a Linux PWM device. The driver controls the timer by using the dmtimer API. Add a platform_data structure for each pwm-omap-dmtimer nodes containing the dmtimers functions in order to get driver not rely on platform specific functions. Cc: Grant Erickson <marathon96@gmail.com> Cc: NeilBrown <neilb@suse.de> Cc: Joachim Eastwood <manabian@gmail.com> Suggested-by: Tony Lindgren <tony@atomide.com> Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Tony Lindgren <tony@atomide.com> [thierry.reding@gmail.com: coding style bikeshed, fix timer leak] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: rcar: Improve accuracy of frequency division settingRyo Kodama1-1/+1
From: Ryo Kodama <ryo.kodama.vz@renesas.com> When period_ns is set to the same value of RCAR_PWM_MAX_CYCLE in rcar_pwm_get_clock_division(), this function should allow such value for improving accuracy of frequency division setting. Signed-off-by: Ryo Kodama <ryo.kodama.vz@renesas.com> Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: lpc32xx: return ERANGE, if requested period is not supportedVladimir Zapolskiy1-3/+3
Instead of silent acceptance of unsupported requested configuration for PWM period and setting the boundary supported value, return -ERANGE to a caller. Duty period value equal to 0 or period is still accepted to allow configuration by PWM sysfs interface, when it is set to 0 by default. For reference this is a list of restrictions on period_ns == 1/freq: | PWM parent clock | parent clock divisor | max freq | min freq | +------------------+----------------------+----------+----------+ | HCLK == 13 MHz | 1 (min) | 50.7 KHz | 198.3 Hz | | HCLK == 13 MHz | 15 (max) | 3.38 KHz | 13.22 Hz | | RTC == 32.7 KHz | 1 (min) | 128 Hz | 0.5 Hz | | RTC == 32.7 KHz | 15 (max) | 8.533 Hz | 0.033 Hz | Note that PWM sysfs interface does not support setting of period more than NSEC_PER_SEC / MAX_INT32 ~ 2 seconds, however this PWM controller supports a period up to 30 seconds. Signed-off-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: lpc32xx: fix and simplify duty cycle and period calculationsVladimir Zapolskiy1-34/+19
The change fixes a problem, if duty_ns is too small in comparison to period_ns (as a valid corner case duty_ns is 0 ns), then due to PWM_DUTY() macro applied on a value the result is overflowed over 8 bits, and instead of the highest bitfield duty cycle value 0xff the invalid duty cycle bitfield value 0x00 is written. For reference the LPC32xx spec defines PWMx_DUTY bitfield description is this way and it seems to be correct: [Low]/[High] = [PWM_DUTY]/[256-PWM_DUTY], where 0 < PWM_DUTY <= 255. In addition according to my oscilloscope measurements LPC32xx PWM is "tristate" in sense that it produces a wave with floating min/max voltage levels for different duty cycle values, for corner cases: PWM_DUTY == 0x01 => signal is in range from -1.05v to 0v .... PWM_DUTY == 0x80 => signal is in range from -0.75v to +0.75v .... PWM_DUTY == 0xff => signal is in range from 0v to +1.05v PWM_DUTY == 0x00 => signal is around 0v, PWM is off Due to this peculiarity on very long period ranges (less than 1KHz) and odd pre-divider values PWM generated wave does not remind a clock shape signal, but rather a heartbit shape signal with positive and negative peaks, so I would recommend to use high-speed HCLK clock as a PWM parent clock and avoid using RTC clock as a parent. The change corrects PWM output in corner cases and prevents any possible overflows in calculation of values for PWM_DUTY and PWM_RELOADV bitfields, thus helper macro definitions may be removed. Signed-off-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: lpc32xx: make device usable with common clock frameworkVladimir Zapolskiy1-2/+2
As a preparatory change for switching LPC32xx mach support to common clock framework fix clk_enable/clk_disable calls without matching clk_prepare/clk_unprepare. The driver can not be used on a platform with common clock framework until clk_prepare/clk_unprepare calls are added, otherwise clk_enable calls will fail and a WARN is generated: # echo 1 > /sys/bus/platform/drivers/lpc32xx-pwm/4005c000.pwm/pwm/pwmchip0/pwm0/enable ------------[ cut here ]------------ WARNING: CPU: 0 PID: 701 at drivers/clk/clk.c:727 clk_core_enable+0x2c/0xa4() Modules linked in: sc16is7xx CPU: 0 PID: 701 Comm: sh Tainted: G W 4.3.0-rc2+ #171 Hardware name: LPC32XX SoC (Flattened Device Tree) Backtrace: [<>] (dump_backtrace) from [<>] (show_stack+0x18/0x1c) [<>] (show_stack) from [<>] (dump_stack+0x20/0x28) [<>] (dump_stack) from [<>] (warn_slowpath_common+0x90/0xb8) [<>] (warn_slowpath_common) from [<>] (warn_slowpath_null+0x24/0x2c) [<>] (warn_slowpath_null) from [<>] (clk_core_enable+0x2c/0xa4) [<>] (clk_core_enable) from [<>] (clk_enable+0x24/0x38) [<>] (clk_enable) from [<>] (lpc32xx_pwm_enable+0x1c/0x40) [<>] (lpc32xx_pwm_enable) from [<>] (pwm_enable+0x48/0x5c) [<>] (pwm_enable) from [<>] (pwm_enable_store+0x5c/0x78) [<>] (pwm_enable_store) from [<>] (dev_attr_store+0x20/0x2c) [<>] (dev_attr_store) from [<>] (sysfs_kf_write+0x44/0x50) [<>] (sysfs_kf_write) from [<>] (kernfs_fop_write+0x134/0x194) [<>] (kernfs_fop_write) from [<>] (__vfs_write+0x34/0xdc) [<>] (__vfs_write) from [<>] (vfs_write+0xb8/0x140) [<>] (vfs_write) from [<>] (SyS_write+0x50/0x90) [<>] (SyS_write) from [<>] (ret_fast_syscall+0x0/0x38) Signed-off-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: lpc32xx: correct number of PWM channels from 2 to 1Vladimir Zapolskiy1-1/+1
LPC32xx SoC has two independent PWM controllers, they have different clock parents, clock gates and even slightly different controls, and each of these two PWM controllers has one output channel. Due to almost similar controls arranged in a row it is incorrectly set that there is one PWM controller with two channels, fix this problem, which at the moment prevents separate configuration of different clock parents and gates for both PWM controllers. The change makes previous PWM device node description incompatible with this update. Signed-off-by: Vladimir Zapolskiy <vz@mleia.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: fsl-ftm: Fix clock enable/disable when using PMStefan Agner1-33/+25
A FTM PWM instance enables/disables three clocks: The bus clock, the counter clock and the PWM clock. The bus clock gets enabled on pwm_request, whereas the counter and PWM clocks will be enabled upon pwm_enable. The driver has three closesly related issues when enabling/disabling clocks during suspend/resume: - The three clocks are not treated differently in regards to the individual PWM state enabled/requested. This can lead to clocks getting disabled which have not been enabled in the first place (a PWM channel which only has been requested going through suspend/resume). - When entering suspend, the current behavior relies on the FTM_OUTMASK register: If a PWM output is unmasked, the driver assumes the clocks are enabled. However, some PWM instances have only 2 channels connected (e.g. Vybrid's FTM1). In that case, the FTM_OUTMASK reads 0x3 if all channels are disabled, even if the code wrote 0xff to it before. For those PWM instances, the current approach to detect enabled PWM signals does not work. - A third issue applies to the bus clock only, which can get enabled multiple times (once for each PWM channel of a PWM chip). This is fine, however when entering suspend mode, the clock only gets disabled once. This change introduces a different approach by relying on the enable and prepared counters of the clock framework and using the frameworks PWM signal states to address all three issues. Clocks get disabled during suspend and back enabled on resume regarding to the PWM channels individual state (requested/enabled). Since we do not count the clock enables in the driver, this change no longer clears the Status and Control registers Clock Source Selection (FTM_SC[CLKS]). However, since we disable the selected clock anyway, and we explicitly select the clock source on reenabling a PWM channel this approach should not make a difference in practice. Signed-off-by: Stefan Agner <stefan@agner.ch> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: lpss: Rework the sequence of programming PWM_SW_UPDATEMika Westerberg1-2/+21
Setting of PWM_SW_UPDATE is bit different in Intel Broxton compared to the previous generation SoCs. Previously it was OK to set the bit many times (from userspace via sysfs for example) before the PWM is actually enabled. Starting from Intel Broxton it seems that we must set PWM_SW_UPDATE only once before the PWM is enabled. Otherwise it is possible that the PWM does not start properly. Change the sequence of how PWM_SW_UPDATE is programmed so that we only set it in pwm_lpss_config() when the PWM is already enabled. The initial setting of PWM_SW_UPDATE will be done when PWM gets enabled. This should make the driver work with the previous generation Intel SoCs and Broxton. Add also small delay after the bit is set to let the hardware propagate it properly. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: lpss: Select core part automaticallyAndy Shevchenko1-10/+5
We have two users of core part right now. Let them to select core part automatically. Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: lpss: Update PWM setting for Broxtonqipeng.zha2-14/+20
For Broxton PWM controller, base unit is defined as 8-bit integer and 14-bit fraction, so need to update base unit setting to output wave with right frequency. Signed-off-by: Qipeng Zha <qipeng.zha@intel.com> Acked-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: bcm2835: Fix email address specificationStefan Wahren1-1/+1
Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: bcm2835: Prevent division by zeroStefan Wahren1-1/+9
It's possible that the PWM clock becomes an orphan. So better check the result of clk_get_rate() in order to prevent a division by zero. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: bcm2835: Calculate scaler in ->config()Stefan Wahren1-5/+3
Currently pwm-bcm2835 assumes a fixed clock rate and stores the resulting scaler in the driver structure. But with the upcoming PWM clock support for clk-bcm2835 the rate could change, so calculate the scaler in the ->config() callback. Signed-off-by: Stefan Wahren <stefan.wahren@i2se.com> Reviewed-by: Eric Anholt <eric@anholt.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-12-16pwm: lpss: Remove ->free() callbackMika Westerberg1-1/+0
The LPSS PWM driver calls pwm_lpss_disable() when the PWM device is released (for example unexported from sysfs). This in turn calls pm_runtime_put() which makes runtime PM count to be unbalanced if the device has not been enabled at this point. This is easy to reproduce: # cd /sys/class/pwm/pwmchip0 # echo 0 > export # echo 0 > unexport The count is unbalanced and prevents the PWM device from being powered on next time. Fix this by removing ->free() callback. There are no resources to be released anyway. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-11Merge tag 'pwm/for-4.4-rc1' of ↵Linus Torvalds15-80/+1323
git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm Pull pwm updates from Thierry Reding: "This round contains a couple of new drivers for the Marvell Berlin family of SoCs, various SoCs from Renesas and Broadcom as well as the backlight PWM present on MediaTek SoCs. Further existing drivers are extended to support a wider range of hardware. The remaining patches are minor fixes and cleanups across the board. Note that one of the patches included in this pull request is against arch/unicore32. I've included it here because I couldn't get a response from Guan Xuetao and I consider the change low-risk. Equivalent patches have been merged and tested in Samsung and PXA trees. The goal is to finally get rid of legacy code paths that have repeatedly been causing headaches" * tag 'pwm/for-4.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (24 commits) pwm: sunxi: Fix whitespace issue pwm: sysfs: Make use of the DEVICE_ATTR_[RW][WO] macro's pwm: sysfs: Remove unnecessary temporary variable unicore32: nb0916: Use PWM lookup table pwm: pwm-rcar: Revise the device tree binding document about compatible pwm: Return -ENODEV if no PWM lookup match is found pwm: sun4i: Add support for PWM controller on sun5i SoCs pwm: Set enable state properly on failed call to enable pwm: lpss: Add support for runtime PM pwm: lpss: Add more Intel Broxton IDs pwm: lpss: Support all four PWMs on Intel Broxton pwm: lpss: Add support for multiple PWMs pwm-pca9685: enable ACPI device found on Galileo Gen2 pwm: Add MediaTek display PWM driver support dt-bindings: pwm: Add MediaTek display PWM bindings pwm: tipwmss: Enable on TI DRA7x and AM437x pwm: atmel-hlcdc: add sama5d2 SoC support. pwm: Add Broadcom BCM7038 PWM controller support Documentation: dt: add Broadcom BCM7038 PWM controller binding pwm: Add support for R-Car PWM Timer ...
2015-11-10pwm: sunxi: Fix whitespace issueOlliver Schinagl1-1/+1
This patch changes no code, it just fixes the whitespacing. Operators should be separated from operands by a single space. Signed-off-by: Olliver Schinagl <oliver@schinagl.nl> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-10pwm: sysfs: Make use of the DEVICE_ATTR_[RW][WO] macro'sOlliver Schinagl1-36/+36
For the npwm property the PWM sysfs interface already made use of the DEVICE_ATTR_RO macro. This patch expands this to the other sysfs properties so that the code base is concise and makes use of this helpful macro. This has the advantage of slightly reducing the code size, improving readability and no longer using magic values for permissions. Signed-off-by: Olliver Schinagl <oliver@schinagl.nl> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-10pwm: sysfs: Remove unnecessary temporary variableOlliver Schinagl1-2/+1
Use the result of pwm_is_enabled() directly instead of storing it in a temporary variable. Signed-off-by: Olliver Schinagl <oliver@schinagl.nl> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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 <thierry.reding@gmail.com>
2015-11-10pwm: sun4i: Add support for PWM controller on sun5i SoCsHans de Goede1-2/+23
The PWM controller on sun5i SoCs is identical to the one found on sun7i SoCs. On the A13 package only one of the 2 pins is routed to the outside, so only advertise one PWM channel there. Signed-off-by: Hans de Goede <hdegoede@redhat.com> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
generated by cgit v1.2.3 (git 2.39.0) at 2024-11-23 00:41:23 +0300