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* ENGR00317376-4 pwm: i.MX: Avoid sample FIFO overflow for i.MX PWM version2Liu Ying2014-06-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The i.MX PWM version2 is embedded in several i.MX SoCs, such as i.MX27, i.MX51 and i.MX6SL. There is a 4-word(16bit) sample FIFO in this IP. Each FIFO slot determines the duty period of a PWM waveform in one full cycle. The IP spec mentions that we should not write a fourth sample because the FIFO will become full and triggers a FIFO write error (FWE) which will prevent the PWM from starting once it is enabled. In order to avoid any sample FIFO overflow issue, this patch clears all sample FIFO by doing software reset in the configuration hook when the controller is disabled or waits for a full PWM cycle to get a relinquished FIFO slot when the controller is enabled and the FIFO is fully loaded. The FIFO overflow issue can be reproduced by the following commands on the i.MX6SL EVK platform, assuming we use PWM2 for the debug LED which is driven by the pin HSIC_STROBE and the maximal brightness is 255. echo 0 > /sys/class/leds/user/brightness echo 0 > /sys/class/leds/user/brightness echo 0 > /sys/class/leds/user/brightness echo 0 > /sys/class/leds/user/brightness echo 255 > /sys/class/leds/user/brightness Here, FWE happens(PWMSR register reads 0x58) and the LED can not be lighten. Another way to reproduce the FIFO overflow issue is to run this script: while true; do echo 255 > /sys/class/leds/user/brightness; done Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
* ENGR00317376-3 pwm: i.MX: Cleanup indentation for register definitionsLiu Ying2014-06-08
| | | | | | | This patch contains no logic change to cleanup indentation for register definitions only. Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
* ENGR00317376-2 pwm: i.MX: Fix the macro MX3_PWMCR_PRESCALER(x) definitionLiu Ying2014-06-08
| | | | | | | | This patch adds missing parentheses around the argument of the macro MX3_PWMCR_PRESCALER(x) to avoid any potential macro expansion issue. Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
* ENGR00317376-1 pwm: i.MX: Don't reset PWMv2 when doing configurationLiu Ying2014-06-08
| | | | | | | | | | | | The patch for ENGR00308394 resets PWMv2 every time we do configuration. This may make the PWM period unstable if we only tune duty period continuously, and finally cause unstable PWM backlight light issue happen. Revert "ENGR00308394 pwm: i.MX: Avoid sample fifo overflow for i.MX pwm version2" This reverts commit 545c7383dfba874180b394f8b00b563a6541e158. Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
* ENGR00308394 pwm: i.MX: Avoid sample fifo overflow for i.MX pwm version2Liu Ying2014-04-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | The i.MX pwm version2 is embedded in several i.MX SoCs, such as i.MX27, i.MX51 and i.MX6SL. There are four 16bit sample fifos in this IP, each of which determines the duty period of a PWM waveform in one full cycle. The IP spec mentions that we should not write a fourth sample because the fifo will become full and trigger a fifo write error(FWE) which will prevent the PWM from starting once it is enabled. In order to avoid any sample fifo overflow issue, this patch does software reset to clear all the sample fifos in the very beginning of the pwm configuration function. The fifo overflow issue can be reproduced by the following commands on the i.MX6SL evk platform, assuming we use pwm2 for the debug LED which is driven by the pin HSIC_STROBE and the maximal brightness is 255. echo 0 > /sys/class/leds/user/brightness echo 0 > /sys/class/leds/user/brightness echo 0 > /sys/class/leds/user/brightness echo 0 > /sys/class/leds/user/brightness echo 255 > /sys/class/leds/user/brightness Here, FWE happens(PWMSR register reads 0x58) and the LED can not be lighten. Acked-by: Shawn Guo <shawn.guo@freescale.com> Signed-off-by: Liu Ying <Ying.Liu@freescale.com>
* ENGR00283508-1 pwm: imx: support pin sleep mode in suspendAnson Huang2014-04-16
| | | | | | | | When system suspend, need to switch pwm pin to sleep mode, this is to save IO power. Using pinctrl mode switch framework to make it happen. Signed-off-by: Anson Huang <b20788@freescale.com>
* drivers/pwm: don't check resource with devm_ioremap_resourceWolfram Sang2013-05-18
| | | | | | | | devm_ioremap_resource does sanity checks on the given resource. No need to duplicate this in the driver. Signed-off-by: Wolfram Sang <wsa@the-dreams.de> Acked-by: Stephen Warren <swarren@nvidia.com>
* pwm: imx: Remove enabled field from struct imx_chipAxel Lin2013-04-02
| | | | | | | | | We can test PWMF_ENABLED bit to know if pwm is enabled or not. Thus remove enabled field from struct imx_chip. Signed-off-by: Axel Lin <axel.lin@ingics.com> Acked-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: Convert to devm_ioremap_resource()Thierry Reding2013-01-22
| | | | | | | | | Convert all uses of devm_request_and_ioremap() to the newly introduced devm_ioremap_resource() which provides more consistent error handling. Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de> Acked-by: Viresh Kumar <viresh.kumar@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge tag 'for-3.8-rc1' of git://gitorious.org/linux-pwm/linux-pwmLinus Torvalds2012-12-19
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Pull pwm changes from Thierry Reding: "A new driver has been added for the SPEAr platform and the TWL4030/6030 driver has been replaced by two drivers that control the regular PWMs and the PWM driven LEDs provided by the chips. The vt8500, tiecap, tiehrpwm, i.MX, LPC32xx and Samsung drivers have all been improved and the device tree bindings now support the PWM signal polarity." Fix up trivial conflicts due to __devinit/exit removal. * tag 'for-3.8-rc1' of git://gitorious.org/linux-pwm/linux-pwm: (21 commits) pwm: samsung: add missing s3c->pwm_id assignment pwm: lpc32xx: Set the chip base for dynamic allocation pwm: lpc32xx: Properly disable the clock on device removal pwm: lpc32xx: Fix the PWM polarity pwm: i.MX: eliminate build warning pwm: Export of_pwm_xlate_with_flags() pwm: Remove pwm-twl6030 driver pwm: New driver to support PWM driven LEDs on TWL4030/6030 series of PMICs pwm: New driver to support PWMs on TWL4030/6030 series of PMICs pwm: pwm-tiehrpwm: pinctrl support pwm: tiehrpwm: Add device-tree binding pwm: pwm-tiehrpwm: Adding TBCLK gating support. pwm: pwm-tiecap: pinctrl support pwm: tiecap: Add device-tree binding pwm: Add TI PWM subsystem driver pwm: Device tree support for PWM polarity pwm: vt8500: Ensure PWM clock is enabled during pwm_config pwm: vt8500: Fix build error pwm: spear: Staticize spear_pwm_config() pwm: Add SPEAr PWM chip driver support ...
| * pwm: i.MX: eliminate build warningLothar Waßmann2012-12-06
| | | | | | | | | | | | | | | | | | | | | | | | compiling the i.MX pwm driver produces the following warning: |drivers/pwm/pwm-imx.c: In function 'imx_pwm_probe': |drivers/pwm/pwm-imx.c:281:7: warning: assignment discards qualifiers from pointer target type Apply a 'const' attribute to the affected variable declaration. Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de> Acked-by: Sascha Hauer <s.hauer@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* | pwm: remove use of __devexitBill Pemberton2012-11-28
| | | | | | | | | | | | | | | | | | CONFIG_HOTPLUG is going away as an option so __devexit is no longer needed. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Acked-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | pwm: remove use of __devinitBill Pemberton2012-11-28
| | | | | | | | | | | | | | | | | | CONFIG_HOTPLUG is going away as an option so __devinit is no longer needed. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Acked-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | pwm: remove use of __devexit_pBill Pemberton2012-11-28
|/ | | | | | | | | CONFIG_HOTPLUG is going away as an option so __devexit_p is no longer needed. Signed-off-by: Bill Pemberton <wfp5p@virginia.edu> Acked-by: Thierry Reding <thierry.reding@avionic-design.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* pwm: i.MX: fix clock lookupPhilipp Zabel2012-09-12
| | | | | | | | | | | | | | | | The i.MX PWM core has two clocks: The ipg clock and the ipg highfreq (peripheral) clock. The ipg clock has to be enabled for this hardware to work. The actual PWM output can either be driven by the ipg clock or the ipg highfreq. The ipg highfreq has the advantage that it runs even when the SoC is in low power modes. This patch requests both clocks and enables the ipg clock for accessing registers and the peripheral clock to actually turn on the PWM. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: i.MX: use per clock unconditionallySascha Hauer2012-09-12
| | | | | | | | | | | | | | The i.MX PWM module has two clocks: The ipg clock and the ipg highfreq (peripheral) clock. The ipg clock has to be enabled for this hardware to work. The actual PWM output can either be driven by the ipg clock or the ipg highfreq. The ipg highfreq has the advantage that it runs even when the SoC is in low power modes. Use the always running clock also on i.MX25. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: i.MX: add devicetree supportPhilipp Zabel2012-09-12
| | | | | | | | | | | | At the same time remove platform based support. No user for this driver has made it into mainline so far, so all we break is out of tree stuff. Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de> Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: i.MX: Use module_platform_driverSascha Hauer2012-09-12
| | | | | | | Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: i.MX: add functions to enable/disable pwm.Sascha Hauer2012-09-12
| | | | | | | | | | | | We used to enable/disable the PWM only by switching the clock on or off. Instead, use the dedicated register bits. These differ on different SoCs, so introduce a SoC specific function for this. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: i.MX: remove unnecessary if in pwm_[en|dis]ableSascha Hauer2012-09-12
| | | | | | | | | | | The PWM core makes sure that pwm_enable/disable are called only once. Still keep the enabled state since we will need it in pwm_config. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: i.MX: factor out SoC specific functionsSascha Hauer2012-09-12
| | | | | | | | | | To cleanup the code and to make it easier to support different SoCs. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> Reviewed-by: Shawn Guo <shawn.guo@linaro.org> Reviewed-by: Benoît Thébaudeau <benoit.thebaudeau@advansee.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* pwm: Convert pwm-imx to use devm_* APIsAxel Lin2012-07-23
| | | | | Signed-off-by: Axel Lin <axel.lin@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
* ARM i.MX: Move i.MX pwm driver to pwm frameworkSascha Hauer2012-07-02
Move the driver to drivers/pwm/ and convert it to use the framework. Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de> [eric@eukrea.com: set chip.dev to prevent probe failure] [eric@eukrea.com: fix pwmchip_add return code test] Signed-off-by: Eric Bénard <eric@eukrea.com> Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
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