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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 <jonathar@broadcom.com> Reviewed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Jonathan Richardson <jonathar@broadcom.com> [thierry.reding@gmail.com: add missing kerneldoc for the lock] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-06pwm: lpss: Add support for runtime PMQipeng Zha3-0/+45
To be able to save some power when PWM is not in use, add support for runtime PM for this driver. This also allows the platform to transition to low power S0ix states when the system is idle. Signed-off-by: Huiquan Zhong <huiquan.zhong@intel.com> Signed-off-by: Qipeng Zha <qipeng.zha@intel.com> Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-06pwm: lpss: Add more Intel Broxton IDsMika Westerberg2-0/+2
Add more Intel Broxton ACPI and PCI IDs to the driver supported devices list. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-06pwm: lpss: Support all four PWMs on Intel BroxtonMika Westerberg3-2/+10
Intel Broxton has similar PWM than Intel Braswell but instead of one it has four PWMs included in one PCI/ACPI device. This patch adds support for all the four PWMs and changes the PCI part of the driver to use 'pwm_lpss_bxt_info' instead. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-06pwm: lpss: Add support for multiple PWMsMika Westerberg2-21/+28
New Intel SoCs such as Broxton will have four PWMs per PCI (or ACPI) device. Each PWM has 1k of register space allocated from the parent device. Add support for this. Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-06pwm-pca9685: enable ACPI device found on Galileo Gen2Andy Shevchenko2-5/+17
There is a chip connected to i2c bus on Intel Galileo Gen2 board. Enable it via ACPI ID INT3492. Cc: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-10-06pwm: Add MediaTek display PWM driver supportYH Huang3-0/+255
Add display PWM driver support to modify backlight for MT8173 and MT6595. The PWM has one channel to control the brightness of the display. When the (high_width / period) is closer to 1, the screen is brighter; otherwise, it is darker. Signed-off-by: YH Huang <yh.huang@mediatek.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-10-06pwm: tipwmss: Enable on TI DRA7x and AM437xVignesh R1-3/+3
TIPWMSS is present on TI's DRA7x and AM437x SoCs. Enable its usage. Instead of adding each SoC individually, use the more generic symbol ARCH_OMAP2PLUS instead. Signed-off-by: Vignesh R <vigneshr@ti.com> Signed-off-by: Sekhar Nori <nsekhar@ti.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-10-06pwm: atmel-hlcdc: add sama5d2 SoC support.Nicolas Ferre1-0/+3
Add sama5d2 hlcdc backlight PWM support. This chip doesn't have to deal with an errata, so it's a simple addition of the mfd compatible string. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-10-06pwm: Add Broadcom BCM7038 PWM controller supportFlorian Fainelli3-0/+354
Add support for the BCM7038-style PWM controller found in all BCM7xxx STB SoCs. This controller has a hardcoded 2 channels per controller, and cascades a variable frequency generator on top of a fixed frequency generator which offers a range of a 148ns period all the way to ~622ms periods. Signed-off-by: Florian Fainelli <f.fainelli@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-10-06misc: atmel_tclib: get and use slow clockBoris Brezillon1-7/+19
Commit dca1a4b5ff6e ("clk: at91: keep slow clk enabled to prevent system hang") added a workaround for the slow clock as it is not properly handled by its users. Get and use the slow clock as it is necessary for the timer counters. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: Thierry Reding <thierry.reding@gmail.com>
2015-10-06pwm: Add support for R-Car PWM TimerYoshihiro Shimoda3-0/+286
This patch adds support for R-Car SoCs PWM Timer. The PWM timer of R-Car H2 has 7 channels. So, we can use the channels if we describe device tree nodes. Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com> Reviewed-by: Simon Horman <horms+renesas@verge.net.au> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-10-06pwm: Add support for the Berlin PWM controllerAntoine Ténart3-0/+229
Add a PWM controller driver for the Marvell Berlin SoCs. This PWM controller has 4 channels. Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com> Acked-by: Sebastian Hesselbarth <sebastian.hesselbarth@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-09-21pwm: atmel-hlcdc: Fix module autoload for OF platform driverLuis de Bethencourt1-0/+1
This platform driver has a OF device ID table but the OF module alias information is not created so module autoloading won't work. This patch adds the missing MODULE_DEVICE_TABLE() for OF to export that information so modules have the correct aliases built-in and autoloading works correctly. A longer explanation by Javier Canillas can be found here: https://lkml.org/lkml/2015/7/30/519 Signed-off-by: Luis de Bethencourt <luisbg@osg.samsung.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-09-09Merge tag 'pwm/for-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwmLinus Torvalds18-55/+697
Pull pwm updates from Thierry Reding: "This set of changes introduces the beginnings of a new API that's based around the concept of states that can be atomically applied. Drivers go to various lengths to implement something similar, which indicates that the core should really be providing the necessary framework. On top of that, there is a bit of cleanup as well as improved kerneldoc and integration into the device-drivers DocBook. Regarding drivers there is a new one for the NXP LPC18xx family of SoCs and a couple of fixes for existing drivers (pca9685, Broadcom Kona and Atmel HLCDC)" * tag 'pwm/for-4.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: ARM: at91: pwm: atmel-hlcdc: Add at91sam9n12 errata pwm: Add NXP LPC18xx PWM/SCT DT binding documentation pwm: NXP LPC18xx PWM/SCT driver pwm-pca9685: Support changing the output frequency pwm-pca9685: Fix several driver bugs pwm: kona: Modify settings application sequence pwm: pca9685: Drop owner assignment pwm: Add to device-drivers documentation pwm: Clean up kerneldoc pwm: Remove useless whitespace pwm: sysfs: Remove unnecessary padding pwm: sysfs: Properly convert from enum to string pwm: Make use of pwm_get_xxx() helpers where appropriate pwm: Add pwm_get_polarity() helper function pwm: Constify PWM device where possible pwm: Add the pwm_is_enabled() helper
2015-09-09ARM: at91: pwm: atmel-hlcdc: Add at91sam9n12 errataJosh Wu1-0/+5
The errata for HLCDC PWM of at91sam9n12 are the same as for at91sam9x5. Signed-off-by: Josh Wu <josh.wu@atmel.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-09-09pwm: NXP LPC18xx PWM/SCT driverAriel D'Alessandro3-0/+478
This commit adds support for NXP LPC18xx PWM/SCT. NXP LPC SoCs family, which includes LPC18xx/LPC43xx, provides a State Configurable Timer (SCT) which can be configured as a Pulse Width Modulator. Other SoCs in that family may share the same hardware. The PWM supports a total of 16 channels, but only 15 can be simultaneously requested. There's only one period, global to all the channels, thus PWM driver will refuse setting different values to it, unless there's only one channel requested. Signed-off-by: Ariel D'Alessandro <ariel@vanguardiasur.com.ar> [thierry.reding@gmail.com: remove excessive padding of fields] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-08-17pwm-pca9685: Support changing the output frequencyClemens Gruber1-1/+64
Previously, period_ns and duty_ns were only used to determine the ratio of ON and OFF time, the default frequency of 200 Hz was never changed. The PCA9685 however is capable of changing the PWM output frequency, which is expected when changing the period. This patch configures the prescaler accordingly, using the formula and notes provided in the PCA9685 datasheet. Bounds checking for the minimum and maximum frequencies, last updated in revision v.4 of said datasheet, is also added. The prescaler is only touched if the period changed, because we have to put the chip into sleep mode to unlock the prescale register. If it is changed, the PWM output frequency changes for all outputs, because there is one prescaler per chip. This is documented in the PCA9685 datasheet and in the comments. If the duty cycle is not changed at the same time as the period, then we restart the PWM output using the duty cycle to period ratio from before the period change. When using LEDs for example, previously set brightness levels stay the same when the frequency changes. Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Steffen Trumtrar <s.trumtrar@pengutronix.de> Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-08-17pwm-pca9685: Fix several driver bugsClemens Gruber1-0/+24
Problems: - When duty_ns == period_ns, the full OFF bit was not cleared and the PWM output of the PCA9685 stayed off. - When duty_ns == period_ns and the catch-all channel was used, the ALL_LED_OFF_L register was not cleared. - The full ON bit was not cleared when setting the OFF time, therefore the exact OFF time was ignored when setting a duty_ns < period_ns Solution: Clear both OFF registers when setting full ON and clear the full ON bit when changing the OFF registers. Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Steffen Trumtrar <s.trumtrar@pengutronix.de> Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-08-17pwm: kona: Modify settings application sequenceJonathan Richardson1-9/+38
Update the driver so that settings are applied in accordance with the most recent version of the hardware spec. The revised sequence clears the trigger bit, waits 400ns, writes settings, sets the trigger bit, and waits another 400ns. This corrects an issue where occasionally a requested change was not properly reflected in the PWM output. Reviewed-by: Arun Ramamurthy <arunrama@broadcom.com> Reviewed-by: Scott Branden <sbranden@broadcom.com> Tested-by: Scott Branden <sbranden@broadcom.com> Reviewed-by: Tim Kryger <tim.kryger@gmail.com> Signed-off-by: Jonathan Richardson <jonathar@broadcom.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-08-17pwm: pca9685: Drop owner assignmentKrzysztof Kozlowski1-1/+0
i2c_driver does not need to set an owner because i2c_register_driver() will set it. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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 <thierry.reding@gmail.com>
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 <thierry.reding@gmail.com>
2015-07-27pwm: sysfs: Remove unnecessary paddingThierry Reding1-3/+3
Padding initializers so that assignment operators align is bound to lead to inconsistencies or churn. Single spaces around the assignment is just fine. Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-07-27pwm: sysfs: Properly convert from enum to stringThierry Reding1-2/+12
The current code will check for polarity in a boolean way. While it is correct that polarity is either normal or inversed, make it more obvious that it's an enumeration by using a switch statement and explicit matches on the enumeration values. Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-07-21pwm: crc: Add Crystalcove (CRC) PWM driverShobhit Kumar3-0/+151
The Crystalcove PMIC provides three PWM signals and this driver exports one of them on the BYT platform which is used to control backlight for DSI panel. This is platform device implementation of the drivers/mfd cell device for CRC PMIC. CC: Samuel Ortiz <sameo@linux.intel.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Alexandre Courbot <gnurou@gmail.com> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Tested-by: Ville Syrjälä <ville.syrjala@linux.intel.com> Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com> Reviewed-by: Varka Bhadram <varkabhadram@gmail.com> Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
2015-07-20pwm: Make use of pwm_get_xxx() helpers where appropriateBoris Brezillon5-9/+12
Use the pwm_get_xxx() helpers instead of directly accessing the fields in struct pwm_device. This will allow us to smoothly move to the atomic update approach. Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-07-20pwm: Add the pwm_is_enabled() helperBoris Brezillon12-26/+26
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 <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-06-23Merge tag 'pwm/for-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwmLinus Torvalds5-26/+89
Pull pwm updates from Thierry Reding: "This has a couple of fixes for Atmel, Samsung and Broadcom drivers. Some preparatory patches for more upcoming Intel work is included as well" * tag 'pwm/for-4.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: pwm: lpss: pci: Add support for Broxton platform pwm: bcm-kona: Don't set polarity in probe pwm: Add pwmchip_add_with_polarity() API pwm: atmel: Fix incorrect CDTY value after disabling pwm: atmel: Fix incorrect CDTY value after enabling pwm: samsung: Use MODULE_DEVICE_TABLE() to include OF modalias pwm: Add support to remove registered consumer lookup tables
2015-06-12pwm: lpss: pci: Add support for Broxton platformQipeng Zha1-0/+2
Add PCI device IDs for Broxton platform. 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>
2015-06-12pwm: bcm-kona: Don't set polarity in probeArun Ramamurthy1-6/+3
Omit setting the polarity to normal during probe and instead use the new pwmchip_add_with_polarity() function to register a PWM chip with inverse polarity by default for all channels to reflect the hardware default. Signed-off-by: Arun Ramamurthy <arunrama@broadcom.com> Reviewed-by: Ray Jui <rjui@broadcom.com> Signed-off-by: Scott Branden <sbranden@broadcom.com> Signed-off-by: Tim Kryger <tim.kryger@gmail.com> Signed-off-by: Jonathan Richardson <jonathar@broadcom.com> [thierry.reding@gmail.com: use pwmchip_add_with_polarity()] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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 <tim.kryger@gmail.com> Signed-off-by: Jonathan Richardson <jonathar@broadcom.com> [thierry.reding@gmail.com: export pwmchip_add_with_polarity()] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-06-12pwm: atmel: Fix incorrect CDTY value after disablingAlexandre Belloni1-0/+28
pwm-leds calls .config() and .disable() in a row. This exhibits that it may happen that the channel gets disabled before CDTY has been updated with CUPD. The issue gets quite worse with long periods. So, ensure that at least one period has past before disabling the channel by polling ISR. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Tested-by: Gaël PORTAY <gael.portay@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-06-12pwm: atmel: Fix incorrect CDTY value after enablingAlexandre Belloni1-17/+18
CUPD is not flushed before enabling the channel so it will update CDTY/CPRD just after one period. So we always set CUPD, even when the channel is not enabled. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-05-21pwm: samsung: Use MODULE_DEVICE_TABLE() to include OF modaliasJavier Martinez Canillas1-0/+1
If the pwm-samsung driver is built as a module, modalias information is not filled so the module is not autoloaded. Use the MODULE_DEVICE_TABLE() macro to export the OF device ID so the module contains that information. Signed-off-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Reviewed-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-05-19pwm: img: Impose upper and lower timebase steps valueNaidu Tellapati1-12/+64
The PWM hardware on Pistachio platform has a maximum timebase steps value to 255. To fix it, let's introduce a compatible-specific data structure to contain the SoC-specific details and use it to specify a maximum timebase. Also, let's limit the minimum timebase to 16 steps, to allow a sane range of duty cycle steps. Fixes: 277bb6a29e00 ("pwm: Imagination Technologies PWM DAC driver") Signed-off-by: Naidu Tellapati <naidu.tellapati@imgtec.com> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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 <sameo@linux.intel.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Alexandre Courbot <gnurou@gmail.com> Cc: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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 <sameo@linux.intel.com> Cc: Linus Walleij <linus.walleij@linaro.org> Cc: Alexandre Courbot <gnurou@gmail.com> Cc: Thierry Reding <thierry.reding@gmail.com> Signed-off-by: Shobhit Kumar <shobhit.kumar@intel.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-03-27pwm: samsung: Fix output race on disablingSjoerd Simons1-1/+31
When disabling the Samsung PWM the output state remains at the level it was at the end of a PWM cycle. In other words, calling pwm_disable() when at 100% duty cycle will keep the output active, while at all other settings the output will go/stay inactive. On top of that the Samsung PWM settings are double-buffered, which means the new settings only get applied at the start of a new PWM cycle. This results in a race if the PWM is at 100% duty cycle and a driver calls: pwm_config(pwm, 0, period); pwm_disable(pwm); In this case the PWMs output will unexpectedly stay active, unless a new PWM cycle happened to start between the register writes in pwm_config() and pwm_disable(). As far as I can tell this is a regression introduced by 3bdf878, before that a call to pwm_config() would call pwm_samsung_enable() which, while heavy-handed, made sure the expected settings were live. To resolve this, while not re-introducing the issues 3bdf878 (flickering as the PWM got reset while in a PWM cycle) fixed, only force an update of the settings when at 100% duty cycle, which shouldn't have any noticeable effect on the output but is enough to ensure the behaviour is as expected on disable. Signed-off-by: Sjoerd Simons <sjoerd.simons@collabora.co.uk> Reviewed-by: Javier Martinez Canillas <javier.martinez@collabora.co.uk> Acked-by: Lukasz Majewski <l.majewski@samsung.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-03-11pwm: mxs: Fix period divider computationGaetan Hug1-2/+6
The driver computes which clock divider it sould be using from the requested period. This computation assumes that the link between the register value and the actual divider value is raising 2 to the power of the registry value. div = 1 << regvalue This is true only for the first 5 values out of 8. Next values are 64, 256 and, 1024 - instead of 32, 64, 128. This affects only the users requesting a period > 0.04369s. Replace the computation with a look-up table. Signed-off-by: Gaetan Hug <ghug@induct.be> Acked-by: Shawn Guo <shawn.guo@linaro.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-03-11pwm: atmel-hlcdc: Add errata handling for sama5d4Nicolas Ferre1-0/+4
sama5d4 SoC also has an errata on the HLCDC PWM. It is the same as the sama5d3 that is forbidding the use of div1 prescaler. Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-03-11pwm: pca9685: Constify struct regmap_configKrzysztof Kozlowski1-1/+1
The regmap_config struct may be const because it is not modified by the driver and regmap_init() accepts pointer to const. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@samsung.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-02-18pwm: tegra: Use NSEC_PER_SECThierry Reding1-1/+1
Instead of using the literal value for the number of nanoseconds per second, use the macro instead to increase readability. Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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 <elfring@users.sourceforge.net> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-01-30pwm: Imagination Technologies PWM DAC driverNaidu Tellapati3-0/+263
The Pistachio SOC from Imagination Technologies includes a Pulse Width Modulation DAC which produces 1 to 4 digital bit-outputs which represent digital waveforms. These PWM outputs are primarily in charge of controlling backlight LED devices. Reviewed-by: Andrew Bresticker <abrestic@chromium.org> Signed-off-by: Naidu Tellapati <Naidu.Tellapati@imgtec.com> Signed-off-by: Sai Masarapu <Sai.Masarapu@imgtec.com> Signed-off-by: Ezequiel Garcia <ezequiel.garcia@imgtec.com> Reviewed-by: Vladimir Zapolskiy <vladimir_zapolskiy@mentor.com> [thierry.reding: fixup license header as discussed on list] Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-01-30pwm: sti: Maintain a bitmap of configured devicesAjit Pal Singh1-19/+11
This patch introduces a bitmap which is used to keep track of the pwm channels which have been configured in a pwm chip. The method used earlier to find the number of configured channels, was to count the pwmdevices with PWMF_REQUESTED field set and period value configured. This was not correct and failed when of_pwm_get()/pwm_get() and then pwm_config() was used. Signed-off-by: Ajit Pal Singh <ajitpal.singh@st.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-01-30pwm: Add Allwinner SoC supportAlexandre Belloni3-0/+377
This adds a generic PWM framework driver for the PWM controller found on Allwinner SoCs. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-01-30pwm: atmel-hlcdc: Prevent division by zeroBoris BREZILLON1-0/+6
The slow and system clock should never return a rate of zero, but this might happen if the clocks property defined in the DT is referencing the wrong clocks. Prevent any division by zero from happening by testing the clk_freq value before calling do_div(). Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-01-30pwm: atmel-hlcdc: Depend on HAVE_CLKThierry Reding1-0/+1
The include/linux/clk.h header defines dummy implementations for the various clk_*() functions if HAVE_CLK is not selected to improve build coverage in randconfig builds. The dummy implementation of clk_get_rate() returns 0, which causes the Atmel HLCDC PWM driver's atmel_hlcdc_pwm_config() implementation to end up calling: do_div(clk_period_ns, 0) On x86, do_div(n, base) will end up evaluating to this: n >>= ilog2(base) with base = 0, the implementation of ilog2() will call ____ilog2_NaN(), which is purposely undefined and results in a linker failure: ERROR: "____ilog2_NaN" [drivers/pwm/pwm-atmel-hlcdc.ko] undefined! The implementation of do_div() checks that base is a power of 2 before calling ilog2(). The compiler doesn't optimize this away, presumably because is_power_of_2() is an inline function and the compiler doesn't or can't inspect it closely enough. ilog2() being a macro it still ends up generating the ____ilog2_NaN() because of the constant 0. The root of the problem is that the driver really should be checking before possibly dividing by zero. That should eventually be fixed, but for now just assume that the clock runs at a sensible frequency when available. Reported-by: Jim Davis <jim.epost@gmail.com> Acked-by: Boris Brezillon <boris.brezillon@free-electrons.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-12-17Merge tag 'pwm/for-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwmLinus Torvalds5-5/+587
Pull pwm updates from Thierry Reding: "There are two new drivers, one for the BCM2835 (Raspberry Pi) and one used in conjunction with the LCD controller on various Atmel SoCs. The Samsung PWM driver can now be built for 64-bit ARM (Exynos7). A couple of fixes have been applied to the FTM PWM driver and system sleep support was added" * tag 'pwm/for-3.19-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: pwm: atmel-hlcdc: add at91sam9x5 and sama5d3 errata handling pwm: ftm: Add Power Management support for FTM PWM pwm: ftm: Add regmap rbtree type cache support pwm: ftm: Correctly track usage count pwm: samsung: Allow Samsung PWM driver to be enabled on Exynos7 pwm: add DT bindings documentation for atmel-hlcdc-pwm driver pwm: add support for atmel-hlcdc-pwm device pwm: Add BCM2835 PWM driver