Commit Graph

55 Commits

Author SHA1 Message Date
Uwe Kleine-König
8db7fdffaa pwm: Switch back to struct platform_driver::remove()
After commit 0edb555a65 ("platform: Make platform_driver::remove()
return void") .remove() is (again) the right callback to implement for
platform drivers.

Convert all pwm drivers to use .remove(), with the eventual goal to drop
struct platform_driver::remove_new(). As .remove() and .remove_new() have
the same prototypes, conversion is done by just changing the structure
member name in the driver initializer.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@baylibre.com>
Link: https://lore.kernel.org/r/20240909073125.382040-2-u.kleine-koenig@baylibre.com
Signed-off-by: Uwe Kleine-König <ukleinek@kernel.org>
2024-09-16 15:24:59 +02:00
Uwe Kleine-König
7550ebf04c pwm: tegra: Make use of devm_pwmchip_alloc() function
This prepares the pwm-tegra driver to further changes of the pwm core
outlined in the commit introducing devm_pwmchip_alloc(). There is no
intended semantical change and the driver should behave as before.

Link: https://lore.kernel.org/r/8719be3d57b0b5cf575b312e5ff41fe0717e3a43.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-22 14:39:26 +01:00
Uwe Kleine-König
aa37f83f7b pwm: tegra: Prepare removing pwm_chip from driver data
This prepares the driver for further changes that will drop struct
pwm_chip chip from struct tegra_pwm_chip. Use the pwm_chip as driver
data instead of the tegra_pwm_chip to get access to the pwm_chip in
tegra_pwm_remove() without using pc->chip.

Link: https://lore.kernel.org/r/2813c63bf1317dee808f4c5c4a9411999f2d5746.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-22 14:39:26 +01:00
Uwe Kleine-König
b662c6e809 pwm: tegra: Drop duplicated tracking of the parent device
The pwmchip stores a pointer to the parent device, so there is no need
to store another copy in driver private data. Drop struct
tegra_pwm_chip::dev and use the pwm_chip's parent pointer instead.

Link: https://lore.kernel.org/r/225f4bfcb15fb69eb818ddb71d623157c447180a.1707900770.git.u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-22 14:39:25 +01:00
Thierry Reding
80943bbdcf pwm: Stop referencing pwm->chip
Drivers have access to the chip via a function argument already, so
there is no need to reference it via the PWM device.

Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-12-20 16:04:14 +01:00
Uwe Kleine-König
384461abca pwm: Manage owner assignment implicitly for drivers
Instead of requiring each driver to care for assigning the owner member
of struct pwm_ops, handle that implicitly using a macro. Note that the
owner member has to be moved to struct pwm_chip, as the ops structure
usually lives in read-only memory and so cannot be modified.

The upside is that new low level drivers cannot forget the assignment and
save one line each. The pwm-crc driver didn't assign .owner, that's not
a problem in practice though as the driver cannot be compiled as a
module.

Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # Intel LPSS
Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> # pwm-{bcm,brcm}*.c
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> # sun4i
Acked-by: Andi Shyti <andi.shyti@kernel.org>
Acked-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> # pwm-visconti
Acked-by: Heiko Stuebner <heiko@sntech.de> # pwm-rockchip
Acked-by: Michael Walle <michael@walle.cc> # pwm-sl28cpld
Acked-by: Neil Armstrong <neil.armstrong@linaro.org> # pwm-meson
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20230804142707.412137-2-u.kleine-koenig@pengutronix.de
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-10-13 10:07:17 +02:00
Rob Herring
0a41b0c5d9 pwm: Explicitly include correct DT includes
The DT of_device.h and of_platform.h date back to the separate
of_platform_bus_type before it as merged into the regular platform bus.
As part of that merge prepping Arm DT support 13 years ago, they
"temporarily" include each other. They also include platform_device.h
and of.h. As a result, there's a pretty much random mix of those include
files used throughout the tree. In order to detangle these headers and
replace the implicit includes with struct declarations, users need to
explicitly include the correct includes.

Signed-off-by: Rob Herring <robh@kernel.org>
Reviewed-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-07-24 13:28:05 +02:00
Uwe Kleine-König
e39cb6f9be pwm: tegra: Convert to platform remove callback returning void
The .remove() callback for a platform driver returns an int which makes
many driver authors wrongly assume it's possible to do error handling by
returning an error code. However the value returned is (mostly) ignored
and this typically results in resource leaks. To improve here there is a
quest to make the remove callback return void. In the first step of this
quest all drivers are converted to .remove_new() which already returns
void.

Trivially convert this driver from always returning zero in the remove
callback to the void returning variant.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-03-30 16:26:38 +02:00
Steven Price
dd1f1da4ad pwm: tegra: Fix 32 bit build
The value of NSEC_PER_SEC << PWM_DUTY_WIDTH doesn't fix within a 32 bit
integer causing a build warning/error (and the value truncated):

  drivers/pwm/pwm-tegra.c: In function ‘tegra_pwm_config’:
  drivers/pwm/pwm-tegra.c:148:53: error: result of ‘1000000000 << 8’ requires 39 bits to represent, but ‘long int’ only has 32 bits [-Werror=shift-overflow=]
    148 |   required_clk_rate = DIV_ROUND_UP_ULL(NSEC_PER_SEC << PWM_DUTY_WIDTH,
        |                                                     ^~

Explicitly cast to a u64 to ensure the correct result.

Fixes: cfcb68817fb3 ("pwm: tegra: Improve required rate calculation")
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
2022-11-11 15:03:59 +01:00
Jon Hunter
5eccd0d9fa pwm: tegra: Ensure the clock rate is not less than needed
When dynamically scaling the PWM clock, the function
dev_pm_opp_set_rate() may set the PWM clock to a rate that is lower than
what is required. The clock rate requested when calling
dev_pm_opp_set_rate() is the minimum clock rate that is needed to drive
the PWM to achieve the required period. Hence, if the actual clock
rate is less than the requested clock rate, then the required period
cannot be achieved and configuring the PWM fails. Fix this by
calling clk_round_rate() to check if the clock rate that will be provided
is sufficient and if not, double the required clock rate to ensure the
required period can be attained.

Fixes: 8c193f4714 ("pwm: tegra: Optimize period calculation")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-11-09 18:30:52 +01:00
Jon Hunter
f271946117 pwm: tegra: Improve required rate calculation
For the case where dev_pm_opp_set_rate() is called to set the PWM clock
rate, the requested rate is calculated as ...

 required_clk_rate = (NSEC_PER_SEC / period_ns) << PWM_DUTY_WIDTH;

The above calculation may lead to rounding errors because the
NSEC_PER_SEC is divided by 'period_ns' before applying the
PWM_DUTY_WIDTH multiplication factor. For example, if the period is
45334ns, the above calculation yields a rate of 5646848Hz instead of
5646976Hz. Fix this by applying the multiplication factor before
dividing and using the DIV_ROUND_UP macro which yields the expected
result of 5646976Hz.

Fixes: 1d7796bdb6 ("pwm: tegra: Support dynamic clock frequency configuration")
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-11-09 18:30:52 +01:00
Uwe Kleine-König
fd3ddd4355 pwm: tegra: Implement .apply() callback
To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply().
This just pushed a variant of pwm_apply_legacy() into the driver that was
slightly simplified because the driver doesn't provide a .set_polarity()
callback.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-05-20 16:28:49 +02:00
Uwe Kleine-König
8c193f4714 pwm: tegra: Optimize period calculation
Dividing by the result of a division looses precision because the result is
rounded twice. E.g. with clk_rate = 48000000 and period = 32760033 the
following numbers result:

	rate = pc->clk_rate >> PWM_DUTY_WIDTH = 187500
	hz = DIV_ROUND_CLOSEST_ULL(100ULL * NSEC_PER_SEC, period_ns) = 3052
	rate = DIV_ROUND_CLOSEST_ULL(100ULL * rate, hz) = 6144

The exact result would be 6142.5061875 and (apart from rounding) this is
found by using a single division. As a side effect is also a tad
cheaper to calculate.

Also using clk_rate >> PWM_DUTY_WIDTH looses precision. Consider for
example clk_rate = 47999999 and period = 106667:

	mul_u64_u64_div_u64(pc->clk_rate >> PWM_DUTY_WIDTH, period_ns,
			    NSEC_PER_SEC) = 19

	mul_u64_u64_div_u64(pc->clk_rate, period_ns,
			    NSEC_PER_SEC << PWM_DUTY_WIDTH) = 20

(The exact result is 20.000062083332033.)

With this optimizations also switch from round-closest to round-down for
the period calculation. Given that the calculations were non-optimal for
quite some time now with variations in both directions which nobody
reported as a problem, this is the opportunity to align the driver's
behavior to the requirements of new drivers. This has several upsides:

 - Implementation is easier as there are no round-nearest variants of
   mul_u64_u64_div_u64().
 - Requests for too small periods are now consistently refused. This was
   kind of arbitrary before, where period_ns < min_period_ns was
   refused, but in some cases min_period_ns isn't actually implementable
   and then values between min_period_ns and the actual minimum were
   rounded up to the actual minimum.

Note that the duty_cycle calculation isn't using the usual round-down
approach yet.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-05-20 16:20:07 +02:00
Uwe Kleine-König
f19460c1d5 pwm: tegra: Rename variable pointing to driver private data
Status quo is that variables of type struct tegra_pwm_chip * are named
"pwm", "chip" or "pc". The two formers are all not optimal because
usually only struct pwm_device * variables are named "pwm" and "chip" is
usually used for variabled of type struct pwm_chip *.

So consistently use the same and non-conflicting name "pc".

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-02-02 18:03:04 +01:00
Dmitry Osipenko
3da9b0feaa pwm: tegra: Add runtime PM and OPP support
The PWM on Tegra belongs to the core power domain and we're going to
enable GENPD support for the core domain. Now PWM must be resumed using
runtime PM API in order to initialize the PWM power state. The PWM clock
rate must be changed using OPP API that will reconfigure the power domain
performance state in accordance to the rate. Add runtime PM and OPP
support to the PWM driver.

Reviewed-by: Ulf Hansson <ulf.hansson@linaro.org>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>
2021-12-16 14:05:23 +01:00
Uwe Kleine-König
2f1a3bd451 pwm: tegra: Assert reset only after the PWM was unregistered
The driver is supposed to stay functional until pwmchip_remove()
returns. So the reset must be asserted only after that.

pwmchip_remove() always returns 0, so the return code can be ignored
which keeps the tegra_pwm_remove() a bit simpler.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:20 +02:00
Uwe Kleine-König
3b8b571fcc pwm: tegra: Don't needlessly enable and disable the clock in .remove()
There is no reason to enable the PWM clock just to assert the reset
control. (If the reset control depends on the clock this is a bug and
probably it doesn't because in .probe() the reset is deasserted without
the clock being enabled.)

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:20 +02:00
Uwe Kleine-König
86f7fa71cd pwm: tegra: Don't modify HW state in .remove callback
A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.

So drop the hardware modification from the .remove() callback.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:20 +02:00
Uwe Kleine-König
c1b8ac969f pwm: tegra: Drop an if block with an always false condition
tegra_pwm_remove() is only called after tegra_pwm_probe() successfully
completed. In this case platform_set_drvdata() was called with a
non-NULL value and so platform_get_drvdata(pdev) cannot return NULL.

Returning an error code from a platform_driver's remove function is
ignored anyway, so it's a good thing this exit path is gone.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-30 19:12:20 +02:00
Uwe Kleine-König
f9a8ee8c8b pwm: Always allocate PWM chip base ID dynamically
Since commit 5e5da1e9fb ("pwm: ab8500: Explicitly allocate pwm chip
base dynamically") all drivers use dynamic ID allocation explicitly. New
drivers are supposed to do the same, so remove support for driver
specified base IDs and drop all assignments in the low-level drivers.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22 11:53:00 +01:00
Yangtao Li
fa44fe41cc pwm: tegra: Convert to devm_platform_ioremap_resource()
Use devm_platform_ioremap_resource() to simplify code.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-12-17 14:18:39 +01:00
Sandipan Patra
1d7796bdb6 pwm: tegra: Support dynamic clock frequency configuration
Added support for dynamic clock freq configuration in PWM kernel driver.
Earlier the PWM driver used to cache boot time clock rate by PWM clock
parent during probe. Hence dynamically changing PWM frequency was not
possible for all the possible ranges. With this change, dynamic
calculation is enabled and it is able to set the requested period from
sysfs knob provided the value is supported by clock source.

Changes mainly have 2 parts:
  - Tegra186 and later chips [1]
  - Tegra210 and prior chips [2]

For [1] - Changes implemented to set pwm period dynamically and also
          checks added to allow only if requested period(ns) is below or
          equals to higher range.

For [2] - Only checks if the requested period(ns) is below or equals to
          higher range defined by max clock limit. The limitation in
          Tegra210 or prior chips are due to the reason of having only
          one PWM controller supporting multiple channels. But later
          chips have multiple PWM controller instances each having
          single channel support.

Signed-off-by: Sandipan Patra <spatra@nvidia.com>
Reviewed-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-06-02 14:25:37 +02:00
Sandipan Patra
2d0c08fcd6 pwm: tegra: Add support for Tegra194
Tegra194 has multiple PWM controllers with each having only one output.

Also the maxmimum frequency is higher than earlier SoCs.

Add support for Tegra194 and specify the number of PWM outputs and
maximum supported frequency using device tree match data.

Signed-off-by: Sandipan Patra <spatra@nvidia.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:04 +02:00
Thomas Gleixner
1621633323 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 1
Based on 2 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 of the license 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 if not write to the free software foundation inc
  51 franklin street fifth floor boston ma 02110 1301 usa

  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 of the license or at
  your option [no]_[pad]_[ctrl] 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 if not write to the free
  software foundation inc 51 franklin street fifth floor boston ma
  02110 1301 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 176 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Jilayne Lovejoy <opensource@jilayne.com>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190519154040.652910950@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21 11:28:39 +02:00
Thierry Reding
f31fb2fe1e pwm: tegra: Remove gratuituous blank line
It's common to follow a device tree ID table by the MODULE_DEVICE_TABLE
immediately, without an extra blank line between.

Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-09-26 16:01:39 +02:00
Philipp Zabel
6b03ef24ea pwm: tegra: Explicitly request exclusive reset control
Commit a53e35db70 ("reset: Ensure drivers are explicit when requesting
reset lines") started to transition the reset control request API calls
to explicitly state whether the driver needs exclusive or shared reset
control behavior. Convert all drivers requesting exclusive resets to the
explicit API call so the temporary transition helpers can be removed.

No functional changes.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Jonathan Hunter <jonathanh@nvidia.com>
Cc: linux-pwm@vger.kernel.org
Cc: linux-tegra@vger.kernel.org
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-08-21 08:53:07 +02:00
Laxman Dewangan
0527eb3723 pwm: tegra: Set maximum pwm clock source per SoC tapeout
The PWM hardware IP is taped-out with different maximum frequency
on different SoCs.

From HW team:

	Before Tegra186, it is 48 MHz.
	In Tegra186, it is 102 MHz.

Add support to limit the clock source frequency to the maximum IP
supported frequency. Provide these values via SoC chipdata.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-06-13 14:30:22 +02:00
Laxman Dewangan
46fa8bc087 pwm: tegra: Read PWM clock source rate in driver init
It is required to know the PWM clock source frequency to calculate the
PWM period.

In driver, the clock source frequency of the PWM does not get change
and, hence, get the clock source frequency in driver init. Get this
values later for period calculation from pwm_config().

This will help in avoiding the clock call for getting clock rate in the
pwm_config() each time.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-13 17:35:40 +02:00
Thierry Reding
6db78b201b pwm: tegra: Avoid potential overflow for short periods
For very short periods, the result of the division might overflow the
unsigned long hz variable (on 32-bit architectures). Avoid that by
making it an unsigned long long. While at it, also remove an unneeded
local variable whose only purpose is to store a temporary computation.

Acked-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-13 17:34:54 +02:00
Laxman Dewangan
4a813b262f pwm: tegra: Add support to configure pin state in suspends/resume
In some of NVIDIA Tegra's platform, PWM controller is used to
control the PWM controlled regulators. PWM signal is connected to
the VID pin of the regulator where duty cycle of PWM signal decide
the voltage level of the regulator output.

When system enters suspend, some PWM client/slave regulator devices
require the PWM output to be tristated.

Add support to configure the pin state via pinctrl frameworks in
suspend and active state of the system.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Acked-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-12 16:10:09 +02:00
Laxman Dewangan
250b76f43f pwm: tegra: Increase precision in PWM rate calculation
The rate of the PWM calculated as follows:

	hz = NSEC_PER_SEC / period_ns;
 	rate = (rate + (hz / 2)) / hz;

This has the precision loss in lower PWM rate.

Change this to have more precision as:

	hz = DIV_ROUND_CLOSEST_ULL(NSEC_PER_SEC * 100, period_ns);
	rate = DIV_ROUND_CLOSEST(rate * 100, hz)

Example:

1. period_ns = 16672000, PWM clock rate is 200 KHz.

	Based on old formula
		hz = NSEC_PER_SEC / period_ns
		   = 1000000000ul/16672000
		   = 59 (59.98)
		rate = (200K + 59/2)/59 = 3390

	Based on new method:
		hz = 5998
		rate = DIV_ROUND_CLOSE(200000*100, 5998) = 3334

	If we measure the PWM signal rate, we will get more accurate
	period with rate value of 3334 instead of 3390.

2.  period_ns = 16803898, PWM clock rate is 200 KHz.

	Based on old formula:
		hz = 59, rate = 3390

	Based on new formula:
		hz = 5951, rate = 3360

	The PWM signal rate of 3360 is more near to requested period
	than 3333.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-12 16:08:15 +02:00
Laxman Dewangan
90241fb9b5 pwm: tegra: Use DIV_ROUND_CLOSEST_ULL() instead of local implementation
Use macro DIV_ROUND_CLOSEST_ULL() for 64-bit division to closest one
instead of implementing the same locally. This increase readability.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-12 16:08:00 +02:00
Laxman Dewangan
e9be88a2f0 pwm: tegra: Add support for Tegra186
Tegra186 has multiple PWM controllers with only one output instead of
one controller with four outputs in earlier SoC generations.

Add support for Tegra186 and detect the number of PWM outputs using
device tree match data.

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Reviewed-by: Alexandre Courbot <acourbot@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:34 +02:00
Hyong Bin Kim
b979ed5314 pwm: tegra: Avoid overflow when calculating duty cycle
duty_ns * (1 << PWM_DUTY_WIDTH) could overflow in integer calculation
when the PWM rate is low. Hence do all calculation on unsigned long long
to avoid overflow.

Signed-off-by: Hyong Bin Kim <hyongbink@nvidia.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:32 +02:00
Victor(Weiguo) Pan
e0ee1a75f4 pwm: tegra: Allow 100 % duty cycle
To get 100 % duty cycle (always high), pulse width needs to be set to
256.

Signed-off-by: Victor(Weiguo) Pan <wpan@nvidia.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:32 +02:00
Rohith Seelaboyina
5dfbd2bd54 pwm: tegra: Add support for reset control
Add reset control of the PWM controller to reset it before
accessing the PWM register.

Signed-off-by: Rohith Seelaboyina <rseelaboyina@nvidia.com>
Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:31 +02:00
Thierry Reding
4f57f5a01f pwm: tegra: Rename mmio_base to regs
The former is much longer to type and is ambiguous because the value
stored in the field is not the (physical) base address of the memory-
mapped I/O registers, but the virtual address of those registers as
mapped through the MMU.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:31 +02:00
Thierry Reding
e17c0b2258 pwm: tegra: Remove useless padding
Use single spaces to separate data type from field names in structure
definitions.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:30 +02:00
Thierry Reding
c009c56475 pwm: tegra: Drop NUM_PWM macro
This macro is used to initialize the ->npwm field of the PWM chip. Use a
literal instead and make all other places rely on ->npwm.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:30 +02:00
Boris Brezillon
5c31252c4a pwm: Add the pwm_is_enabled() helper
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>
2015-07-20 09:46:06 +02:00
Thierry Reding
b65af27ad8 pwm: tegra: Use NSEC_PER_SEC
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>
2015-02-18 08:40:29 +01:00
Wolfram Sang
f05fae14a1 pwm: drop owner assignment from platform_drivers
A platform_driver does not need to set an owner, it will be populated by the
driver core.

Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
2014-10-20 16:21:28 +02:00
Jingoo Han
474b69025d pwm: tegra: Remove unnecessary OOM messages
The site-specific OOM messages are unnecessary, because they
duplicate the MM subsystem generic OOM message.

Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-04-28 13:37:48 +02:00
Thierry Reding
3dd0a90947 pwm: Fill in missing .owner fields
Some drivers don't set the .owner fields of the struct device_driver or
struct pwm_ops, which causes the module usage count to become wrong.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-06-12 13:18:29 +02:00
Wolfram Sang
362e9cd2f5 drivers/pwm: don't check resource with devm_ioremap_resource
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>
2013-05-18 11:55:58 +02:00
Thierry Reding
f1a8870aeb pwm: Constify OF match tables
A few drivers already annotate this properly. Make the same change for
all other OF supporting drivers.

Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Acked-by: Alexandre Pereira da Silva <aletes.xgr@gmail.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
2013-04-23 07:42:20 +02:00
Linus Torvalds
3eb05225ee pwm: Changes for v3.9-rc1
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.
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Merge tag 'for-3.9-rc1' of git://gitorious.org/linux-pwm/linux-pwm

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
2013-02-26 09:34:29 -08:00
Stephen Warren
838bf09d4f pwm: tegra: assume CONFIG_OF
Tegra only supports, and always enables, device tree. Remove all ifdefs
for DT support from the driver.

Signed-off-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Thierry Reding <thierry.reding@avionic-design.de>
2013-02-15 23:27:51 +01:00
Thierry Reding
6d4294d163 pwm: Convert to devm_ioremap_resource()
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>
2013-01-22 11:41:57 -08:00
Bill Pemberton
77f37917a6 pwm: remove use of __devexit
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>
2012-11-28 12:23:41 -08:00