PWM is now consistently spelled in all uppercase letters. For the Atmel
driver the entry now also mentions Atmel to make it easier to find.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

This patch adds a PWM driver based on Atmel Timer Counter Block. The
Timer Counter Block is used in Waveform generator mode.

A Timer Counter Block provides up to 6 PWM devices grouped by 2:
* group 0 = PWM 0 and 1
* group 1 = PWM 2 and 3
* group 2 = PMW 4 and 5

PWM devices in a given group must be configured with the same period
value. If a PWM device in a group tries to change the period value and
the other device is already configured with a different value an error
will be returned.

This driver requires device tree support. The Timer Counter Block number
used to create a PWM chip is given by the tc-block field in an
"atmel,tcb-pwm" compatible node.

This patch was tested on kizbox board (at91sam9g20 SoC) with pwm-leds.
Signed-off-by: NBoris BREZILLON <linux-arm@overkiz.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

This driver only supported the Charging indicator LED.
New set of drivers going to provide support for both PWMs and LEDs for twl4030
and twl6030 series of PMICs.
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

The driver supports the following LED outputs as generic PWM driver:
TWL4030 LEDA and LEDB (PWMA and PWMB)
TWL6030 Charging indicator LED (PWM LED)

On TWL6030 when the PWM requested LED is configured to be controlled by SW.
In this case the user can enable/disable and set the duty period freely.
When the PWM has been freed, the LED driver is put back to HW control.
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

The driver supports the following PWM outputs:
TWL4030 PWM0 and PWM1
TWL6030 PWM1 and PWM2

On TWL4030 the PWM signals are muxed. Upon requesting the PWM the driver
will select the correct mux so the PWM can be used. When the PWM has been
freed the original configuration is going to be restored.
Signed-off-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

In some platforms (like am33xx), PWM sub modules (ECAP, EHRPWM, EQEP)
are integrated to PWM subsystem. These PWM submodules has resources
shared and only one register bit-field is provided to control
module/clock enable/disable, makes it difficult to handle common
resources from independent PWMSS submodule drivers.

So the solution here implemented in this patch is, to create driver for
PWMSS and take the role of parent driver for PWM submodules. PWMSS
parent driver enumerates all the child nodes under PWMSS module. Also
symbol "pwmss_submodule_state_change" exported to enable clock gating
for individual PWMSS submodules, and submodule drivers has to enable
clock gating from their drivers.

As this is only supported during DT boot, the parent/child relationship
is created and populated in DT execution flow. The only required change
is inside DTS file, making EHRPWM & ECAP as a child to PWMSS node.
Signed-off-by: NPhilip, Avinash <avinashphilip@ti.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

Add support for PWM chips present on SPEAr platforms. These PWM
chips support 4 channel output with programmable duty cycle and
frequency.

More details on these PWM chips can be obtained from relevant
chapter of reference manual, present at following[1] location.

1. http://www.st.com/internet/mcu/product/251211.jsp

Cc: Thierry Reding <thierry.reding@avionic-design.de>
Signed-off-by: NShiraz Hashim <shiraz.hashim@st.com>
Signed-off-by: NViresh Kumar <viresh.kumar@linaro.org>
Reviewed-by: NVipin Kumar <vipin.kumar@st.com>
Acked-by: NViresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

This commit moves the driver to drivers/pwm and converts it to the new
PWM framework.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Acked-by: NLars-Peter Clausen <lars@metafoo.de>
Tested-by: NLars-Peter Clausen <lars@metafoo.de>
Acked-by: NRalf Baechle <ralf@linux-mips.org>

This commit moves the driver to drivers/pwm and converts it to the new
PWM framework.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Tested-by: NQin Rui <qinrui@mprc.pku.edu.cn>
Acked-by: NGuan Xuetao <gxt@mprc.pku.edu.cn>

This commit moves the driver to drivers/pwm and converts it to the new
PWM framework.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Acked-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NArun Murthy <arun.murthy@stericsson.com>

This commit moves the driver to drivers/pwm and converts it to the new
PWM framework. In order for this to work properly, register the PWM as
child of the multi-function TWL6030 device.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Acked-by: NPeter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: NSamuel Ortiz <sameo@linux.intel.com>

The Kconfig help text should help the user understand what functionality
is provided by an option. This is especially true for new subsystems. An
improved help text is provided by this commit in the hopes of clarifying
the usefulness of the PWM framework.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>
Acked-by: NBorislav Petkov <bp@alien8.de>

Enhanced high resolution PWM module (EHRPWM) hardware can be used to
generate PWM output over 2 channels. This commit adds PWM driver support
for EHRPWM device present on AM33XX SOC. Current implementation supports
simple PWM functionality.
Reviewed-by: NVaibhav Bedia <vaibhav.bedia@ti.com>
Signed-off-by: NPhilip, Avinash <avinashphilip@ti.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

ECAP hardware on AM33XX SOC supports auxiliary PWM (APWM) feature. This
commit adds PWM driver support for ECAP hardware on AM33XX SOC.

In the ECAP hardware, each PWM pin can also be configured to be in
capture mode. Current implementation only supports PWM mode of
operation. Also, hardware supports sync between multiple PWM pins but
the driver supports simple independent PWM functionality.
Reviewed-by: NVaibhav Bedia <vaibhav.bedia@ti.com>
Signed-off-by: NPhilip, Avinash <avinashphilip@ti.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

Add lpc32xx SOC PWM driver.
Signed-off-by: NAlexandre Pereira da Silva <aletes.xgr@gmail.com>
Acked-by: NRoland Stigge <stigge@antcom.de>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

In order to avoid duplicate symbols with legacy PWM API implementations,
the new PWM framework needs to conflict with any of the existing legacy
implementations. This is done in two ways: for implementations provided
by drivers, a conflict is added to the driver to ensure it will have to
be ported to the PWM subsystem before it can coexist with other PWM
providers. For architecture-specific code, the conflict is added to the
PWM symbol to avoid confusion when a previously picked platform or
machine can no longer be selected because of the PWM subsystem being
included.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

Use global reset function stmp_reset_block instead of mxs_reset_block
to remove <mach/common.h> inclusion.
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

Add generic PWM framework driver (DT only) for Freescale MXS.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: NShawn Guo <shawn.guo@linaro.org>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

Move the driver to drivers/pwm/ and convert it to use the framework.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Cc: Alexey Charkov <alchark@gmail.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

Move the driver to drivers/pwm/ and convert it to use the framework.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kukjin Kim <kgene.kim@samsung.com>
[eric@eukrea.com: fix pwmchip_add return code test]
Signed-off-by: NEric Bénard <eric@eukrea.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

Move the driver to drivers/pwm/ and convert it to use the framework.
Signed-off-by: NSascha 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: NEric Bénard <eric@eukrea.com>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

This commit moves the PXA PWM driver to the drivers/pwm subdirectory and
converts it to use the new PWM framework.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

This commit moves the Blackfin PWM driver to the drivers/pwm sub-
directory and converts it to register with the new PWM framework.
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

This commit adds a generic PWM framework driver for the PWFM controller
found on NVIDIA Tegra SoCs. The driver is based on code from the
Chromium kernel tree and was originally written by Gary King (NVIDIA)
and later modified by Simon Que (Chromium).
Acked-by: NStephen Warren <swarren@wwwdotorg.org>
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>

This patch adds framework support for PWM (pulse width modulation) devices.

The is a barebone PWM API already in the kernel under include/linux/pwm.h,
but it does not allow for multiple drivers as each of them implements the
pwm_*() functions.

There are other PWM framework patches around from Bill Gatliff. Unlike
his framework this one does not change the existing API for PWMs so that
this framework can act as a drop in replacement for the existing API.

Why another framework?

Several people argue that there should not be another framework for PWMs
but they should be integrated into one of the existing frameworks like led
or hwmon. Unlike these frameworks the PWM framework is agnostic to the
purpose of the PWM. In fact, a PWM can drive a LED, but this makes the
LED framework a user of a PWM, like already done in leds-pwm.c. The gpio
framework also is not suitable for PWMs. Every gpio could be turned into
a PWM using timer based toggling, but on the other hand not every PWM hardware
device can be turned into a gpio due to the lack of hardware capabilities.

This patch does not try to improve the PWM API yet, this could be done in
subsequent patches.
Signed-off-by: NSascha Hauer <s.hauer@pengutronix.de>
Acked-by: NKurt Van Dijck <kurt.van.dijck@eia.be>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Reviewed-by: NMatthias Kaehlcke <matthias@kaehlcke.net>
Reviewed-by: NMark Brown <broonie@opensource.wolfsonmicro.com>
Reviewed-by: NShawn Guo <shawn.guo@linaro.org>
[thierry.reding@avionic-design.de: fixup typos, kerneldoc comments]
Signed-off-by: NThierry Reding <thierry.reding@avionic-design.de>