Commit Graph

11 Commits

Author SHA1 Message Date
Thomas Gleixner d2912cb15b treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500
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 version 2 as
  published by the free software foundation

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license version 2 as
  published by the free software foundation #

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 4122 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Enrico Weigelt <info@metux.net>
Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org>
Reviewed-by: Allison Randal <allison@lohutok.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190604081206.933168790@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-06-19 17:09:55 +02:00
David Rivshin 43725feb59 pwm: omap-dmtimer: Return -EPROBE_DEFER if no dmtimer platform data
If a pwm-omap-dmtimer is probed before the dmtimer it uses, the platform
data won't be set yet.

Fixes: ac30751df9 ("ARM: OMAP: pdata-quirks: Remove unused timer pdata")
Cc: <stable@vger.kernel.org> # 4.17+
Signed-off-by: David Rivshin <drivshin@allworx.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Tested-by: Pavel Machek <pavel@ucw.cz>
Acked-by: Ladislav Michl <ladis@linux-mips.org>
Tested-by: Andreas Kemnade <andreas@kemnade.info>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-08-20 11:32:19 +02:00
Keerthy b7290cf6ff pwm: pwm-omap-dmtimer: Adapt driver to utilize dmtimer pdata ops
Adapt driver to utilize dmtimer pdata ops instead of pdata-quirks.

Signed-off-by: Keerthy <j-keerthy@ti.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2018-02-22 10:54:24 -08:00
Ivaylo Dimitrov a74a198249 pwm: omap-dmtimer: Allow for setting dmtimer clock source
OMAP GP timers can have different input clocks that allow different PWM
frequencies. However, there is no other way of setting the clock source but
through clocks or clock-names properties of the timer itself. This limits
PWM functionality to only the frequencies allowed by the particular clock
source. Allowing setting the clock source by PWM rather than by timer
allows different PWMs to have different ranges by not hard-wiring the clock
source to the timer.

Signed-off-by: Ivaylo Dimitrov <ivo.g.dimitrov.75@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Acked-by: Thierry Reding <treding@nvidia.com>
Acked-by: Pali Rohár <pali.rohar@gmail.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
2016-06-29 21:54:00 -07:00
Boris Brezillon 4b58896f72 pwm: Use pwm_get/set_xxx() helpers where appropriate
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>
2016-05-17 14:44:59 +02:00
David Rivshin 922201d129 pwm: omap-dmtimer: Add debug message for effective period and duty cycle
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>
2016-03-23 17:11:48 +01:00
David Rivshin 7b0883f338 pwm: omap-dmtimer: Round load and match values rather than truncate
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: 6604c6556d ("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>
2016-03-23 17:11:47 +01:00
David Rivshin cd37888142 pwm: omap-dmtimer: Add sanity checking for load and match values
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: 6604c6556d ("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>
2016-03-23 17:11:46 +01:00
David Rivshin f8caa79226 pwm: omap-dmtimer: Fix inaccurate period and duty cycle calculations
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: 6604c6556d ("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>
2016-03-23 17:11:45 +01:00
Dan Carpenter 074726402b pwm: omap-dmtimer: Potential NULL dereference on error
"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>
2016-01-04 08:58:33 +01:00
Neil Armstrong 6604c6556d pwm: Add PWM driver for OMAP using dual-mode timers
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>
2015-12-16 17:25:37 +01:00