Commit Graph

25 Commits

Author SHA1 Message Date
Uwe Kleine-König
faaa222221 pwm: omap-dmtimer: Don't check the return code of pwmchip_remove()
pwmchip_remove() returns always 0. Don't use the value to make it
possible to eventually change the function to return void. Also the
driver core ignores the return value of pwm_omap_dmtimer_remove()
and considers the device removed anyhow. So returning early results
in a resource leak.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-09-02 21:38:52 +02:00
Uwe Kleine-König
e9fdf122cf pwm: Simplify all drivers with explicit of_pwm_n_cells = 3
With the previous commit there is no need for the lowlevel driver any
more to specify it it uses two or three cells. So simplify accordingly.

The only non-trival change affects the pwm-rockchip driver: It used to only
support three cells if the hardware supports polarity. Now the default
number depends on the device tree which has to match hardware anyhow
(and if it doesn't the error is just a bit delayed as a PWM handle with
an inverted setting is catched when pwm_apply_state() is called).

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-05-25 18:19:15 +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
Alexander A. Klimov
216a094de2 pwm: Replace HTTP links with HTTPS ones
Rationale:
Reduces attack surface on kernel devs opening the links for MITM
as HTTPS traffic is much harder to manipulate.

Deterministic algorithm:
For each file:
  If not .svg:
    For each line:
      If doesn't contain `\bxmlns\b`:
        For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`:
          If neither `\bgnu\.org/license`, nor `\bmozilla\.org/MPL\b`:
            If both the HTTP and HTTPS versions
            return 200 OK and serve the same content:
              Replace HTTP with HTTPS.

Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-07-30 11:27:13 +02:00
Lee Jones
dfd9b6154d pwm: omap-dmtimer: Repair pwm_omap_dmtimer_chip's broken kerneldoc header
Argument descriptions must be prepended with a '@' to be understood
by the kerneldoc tooling/parsers/validators.

Fixes the following W=1 warning:

  drivers/pwm/pwm-omap-dmtimer.c:70: warning: Function parameter or member 'dm_timer_pdev' not described in 'pwm_omap_dmtimer_chip'

Cc: Tony Lindgren <tony@atomide.com>
Cc: Joachim Eastwood <manabian@gmail.com>
Cc: NeilBrown <neilb@suse.de>
Cc: Grant Erickson <marathon96@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-07-30 11:27:12 +02:00
Lokesh Vutla
6b28fb6f3c pwm: omap-dmtimer: Implement .apply callback
Implement .apply callback and drop the legacy callbacks(enable, disable,
config, set_polarity). In .apply() check for the current hardware status
before changing the PWM configuration.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:08 +02:00
Lokesh Vutla
e793eef806 pwm: omap-dmtimer: Do not disable PWM before changing period/duty_cycle
Only the Timer control register(TCLR) cannot be updated when the timer
is running. Registers like Counter register (TCRR), loader register
(TLDR) and match register (TMAR) can be updated while the counter is
running. Since TCLR is not updated in pwm_omap_dmtimer_config(), do not
stop the timer for period/duty_cycle update.

Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:07 +02:00
Lokesh Vutla
867beb60d1 pwm: omap-dmtimer: Fix PWM enabling sequence
To configure DM timer in PWM mode the following needs to be set in
OMAP_TIMER_CTRL_REG using set_pwm callback:
- Set toggle mode on PORTIMERPWM output pin
- Set trigger on overflow and match on PORTIMERPWM output pin.
- Set auto reload

This is a one time configuration and needs to be set before the start of
the DM timer. But the current driver tries to set the same configuration
for every period/duty cycle update, which is not needed. So move the PWM
setup before enabling timer and do not update it in
pwm_omap_dmtimer_config().

Tested-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:07 +02:00
Lokesh Vutla
348fb6f7fb pwm: omap-dmtimer: Update description for PWM OMAP DM timer
Update the description with a brief about how PWM is generated using
OMAP DM timer and add limitations for the PWM generations. Also add a
link to the reference manual.

Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:06 +02:00
Lokesh Vutla
54091b5f19 pwm: omap-dmtimer: Drop unused header file
pwm_omap_dmtimer.h is used only:
- to typedef struct omap_dm_timer to pwm_omap_dmtimer
- for macro PWM_OMAP_DMTIMER_TRIGGER_OVERFLOW_AND_COMPARE
Rest of the file is pretty mush unsed. So reuse omap_dm_timer
and OMAP_TIMER_TRIGGER_OVERFLOW_AND_COMPARE in pwm-omap-dmtimer.c
and delete the header file.

Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30 18:03:06 +02:00
Lokesh Vutla
02e6d546e3 clocksource/drivers/timer-ti-dm: Enable autoreload in set_pwm
dm timer ops set_load() api allows to configure the load value and to
set the auto reload feature. But auto reload feature is independent of
load value and should be part of configuring pwm. This way pwm can be
disabled by disabling auto reload feature using set_pwm() so that the
current pwm cycle will be completed. Else pwm disabling causes the
cycle to be stopped abruptly.

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Acked-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200305082715.15861-7-lokeshvutla@ti.com
2020-03-16 12:40:51 +01:00
Uwe Kleine-König
c7cb3a1dd5 pwm: omap-dmtimer: put_device() after of_find_device_by_node()
This was found by coccicheck:

	drivers/pwm/pwm-omap-dmtimer.c:304:2-8: ERROR: missing put_device;
	call of_find_device_by_node on line 255, but without a corresponding
	object release within this function.

Reported-by: Markus Elfring <elfring@users.sourceforge.net>
Fixes: 6604c6556d ("pwm: Add PWM driver for OMAP using dual-mode timers")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 12:32:37 +01:00
Uwe Kleine-König
c4cf7aa57e pwm: omap-dmtimer: Simplify error handling
Instead of doing error handling in the middle of ->probe(), move error
handling and freeing the reference to timer to the end.

This fixes a resource leak as dm_timer wasn't freed when allocating
*omap failed.

Implementation note: The put: label was never reached without a goto and
ret being unequal to 0, so the removed return statement is fine.

Fixes: 6604c6556d ("pwm: Add PWM driver for OMAP using dual-mode timers")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 12:31:19 +01:00
Uwe Kleine-König
43efdc8f0e pwm: omap-dmtimer: Remove PWM chip in .remove before making it unfunctional
In the old code (e.g.) mutex_destroy() was called before
pwmchip_remove(). Between these two calls it is possible that a PWM
callback is used which tries to grab the mutex.

Fixes: 6604c6556d ("pwm: Add PWM driver for OMAP using dual-mode timers")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-20 12:29:34 +01:00
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