Commit Graph

26 Commits

Author SHA1 Message Date
Thierry Reding
9193c16e5a pwm: atmel: Consolidate driver data initialization
This helps readability by separating the driver-specific bits from the
PWM framework bits.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:11 +02:00
Thierry Reding
d85b9ce198 pwm: atmel: Remove unneeded check for match data
Since the driver is now exclusively DT, it only binds if it finds a
match in the of_device_id table. But in that case the associated data
can never be NULL, so drop the unnecessary check.

While at it, drop the extra local variable and store the pointer to
this per-SoC data in the driver data directly.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:11 +02:00
Kamel Bouhara
3d4d85741a pwm: atmel: Remove platform_device_id and use only dt bindings
Since commit 26202873bb ("avr32: remove support for AVR32
architecture") there is no more user of platform_device_id and we
should only use dt bindings

Signed-off-by: Kamel Bouhara <kamel.bouhara@bootlin.com>
Acked-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Acked-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:10 +02:00
Uwe Kleine-König
71523d1812 pwm: Ensure pwm_apply_state() doesn't modify the state argument
It is surprising for a PWM consumer when the variable holding the
requested state is modified by pwm_apply_state(). Consider for example a
driver doing:

        #define PERIOD 5000000
        #define DUTY_LITTLE 10
        ...
        struct pwm_state state = {
                .period = PERIOD,
                .duty_cycle = DUTY_LITTLE,
                .polarity = PWM_POLARITY_NORMAL,
                .enabled = true,
        };

        pwm_apply_state(mypwm, &state);
        ...
        state.duty_cycle = PERIOD / 2;
        pwm_apply_state(mypwm, &state);

For sure the second call to pwm_apply_state() should still have
state.period = PERIOD and not something the hardware driver chose for a
reason that doesn't necessarily apply to the second call.

So declare the state argument as a pointer to a const type and adapt all
drivers' .apply callbacks.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 03:25:10 +02:00
Thomas Gleixner
f50a7f3d92 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 191
Based on 1 normalized pattern(s):

  licensed under gplv2

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-only

has been chosen to replace the boilerplate/reference in 99 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Steve Winslow <swinslow@gmail.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190528170027.163048684@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:29:21 -07:00
Thierry Reding
d7d96312fe pwm: atmel: Remove useless symbolic definitions
The values that these symbols define are only assigned to the per-SoC
structure where the context is clear, so there's no need for the extra
symbolic name.

Acked-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-03-04 12:52:49 +01:00
Claudiu Beznea
74d0c3b205 pwm: atmel: Add support for SAM9X60's PWM controller
Add support for SAM9X60's PWM controller.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-03-04 11:57:44 +01:00
Claudiu Beznea
abcbe3733e pwm: atmel: Rename objects of type atmel_pwm_data
Rename objects of type atmel_pwm_data to contain chip name instead of
version number.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-03-04 11:56:48 +01:00
Claudiu Beznea
0285827d54 pwm: atmel: Add support for controllers with 32 bit counters
SAM9X60's PWM controller uses 32 bits counters thus it could generate
signals with higher period and duty cycles than the old ones. Prepare
the current driver to be able to work with old controllers (that uses
16 bits counters) and with the new SAM9X60's controller, by providing
counters information based on compatible string.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-03-04 11:56:08 +01:00
Claudiu Beznea
53784159f6 pwm: atmel: Add struct atmel_pwm_data
Add struct atmel_pwm_data to embed different per controller information.
It prepares adding support for another similar controller that needs
additional information. At this stage, embed a member of type struct
atmel_pwm_registers in it.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-03-04 11:50:33 +01:00
Claudiu Beznea
44521afa57 pwm: atmel: Enable PWM on sama5d2
sama5d2 can use the same atmel_pwm_data as sama5d3.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Acked-by: Rob Herring <robh@kernel.org>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-06 17:45:03 +02:00
Claudiu Beznea
1a722aad58 pwm: atmel: Switch to atomic PWM
The currently Atmel PWM controllers supported by this driver could
change period or duty factor without channel disable, for regular
channels (sama5d3 support this by using period or duty factor update
registers, sam9rl support this by writing channel update register and
select the corresponding update: period or duty factor). The chip
doesn't support run time changings of signal polarity. To take advantage
of atomic PWM framework and let controller works without glitches, in
this patch only the duty factor could be changed without disabling PWM
channel. For period and signal polarity the atomic PWM is simulated by
disabling + enabling the right PWM channel.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-06 17:45:02 +02:00
Thierry Reding
8c0216f377 pwm: Remove .can_sleep from struct pwm_chip
All PWM devices have been marked as "might sleep" since v4.5, there is
no longer a need to differentiate on a per-chip basis.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-04 09:40:54 +01:00
Thierry Reding
017bb04e84 pwm: atmel: Use of_device_get_match_data()
Use of_device_get_match_data() instead of an open-coded variant.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:36 +02:00
Thierry Reding
313b78efea pwm: atmel: Fix checkpatch warnings
Avoid an overly long line by moving a comment around, and remove a use
of else-after-return.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:36 +02:00
Guillermo Rodriguez
f718c54c1a pwm: atmel: Fix disabling of PWM channels
When disabling a PWM channel, the PWM clock was being stopped
immediately after writing to PWM_DIS. As a result, the disabling
of the PWM channel did not complete properly, and the PWM output
might be left at the wrong level.

Fix this by waiting for the channel to be effectively disabled
(by checking the PWM_SR register) before disabling the clock.

Signed-off-by: Guillermo Rodriguez <guille.rodriguez@gmail.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-07-11 12:49:35 +02:00
Boris Brezillon
15da7b5001 pwm: Make use of pwm_get_xxx() helpers where appropriate
Use the pwm_get_xxx() helpers instead of directly accessing the fields
in struct pwm_device. This will allow us to smoothly move to the atomic
update approach.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-07-20 09:53:22 +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
Alexandre Belloni
472ac3dcac pwm: atmel: Fix incorrect CDTY value after disabling
pwm-leds calls .config() and .disable() in a row. This exhibits that it
may happen that the channel gets disabled before CDTY has been updated
with CUPD. The issue gets quite worse with long periods. So, ensure that
at least one period has past before disabling the channel by polling
ISR.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Tested-by: Gaël PORTAY <gael.portay@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-06-12 11:16:12 +02:00
Alexandre Belloni
4c027f7ba8 pwm: atmel: Fix incorrect CDTY value after enabling
CUPD is not flushed before enabling the channel so it will update
CDTY/CPRD just after one period. So we always set CUPD, even when the
channel is not enabled.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-06-12 11:12:20 +02:00
Nikolaus Voss
e2e0897010 pwm: atmel: Fix calculation of prescale value
The prescale value used for calculating the period was incremented
afterwards, thus the resulting prescale value is by one too high.
This resulted in a PWM frequency only half as high as requested.

This patch moves the 64 bit division out of the prescale loop to
correct the above issue and make the calculation more efficient.

Signed-off-by: Nikolaus Voss <n.voss@weinmann-emt.de>
Tested-by: Bo Shen <voice.shen@atmel.com>
Acked-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-09-25 08:52:39 +02:00
Alexandre Belloni
cf3a384b34 pwm: atmel: set pwm_chip can_sleep flag
atmel_pwm_config() calls clk_get_rate() which might sleep, so we need to
set pwm_chip can_sleep flag.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-05-21 12:08:57 +02:00
Alexandre Belloni
916030db43 pwm: atmel: correct CDTY calculation
From the datasheet, the actual duty cycle is:

	(period - (1 / clk) * CDTY) / period

This actually correct the polarity of the PWM and solves the issue that
pwm-leds exhibits: when setting a duty cycle of 0 and then disabling a
channel, the level was wrong (1 when the polarity was normal and 0 when
the polarity was inversed).

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-03-18 20:47:48 +01:00
Alexandre Belloni
8db9e29fe5 pwm: atmel: Fix polarity handling
When atmel_pwm_config() calculates and then sets the prescaler, it is
overwriting the channel's CMR register so we are losing the CPOL
configuration.

As atmel_pwm_config() is always called before enabling a channel,
inverting the polarity doesn't work.

Fix that by reading CMR first and only overwriting the prescaler bits.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@atmel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2014-03-18 20:47:31 +01:00
Bo Shen
6a6833563f pwm: atmel-pwm: Do not unprepare clock after successful registration
When the PWM controller is registered successfully, the clock can not
unprepare, so fix it.

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-12-20 10:48:43 +01:00
Bo Shen
32b16d46e4 pwm: atmel-pwm: Add Atmel PWM controller driver
Add a PWM framework driver for the PWM controller found on Atmel SoCs.

Signed-off-by: Bo Shen <voice.shen@atmel.com>
Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com>
[thierry.reding: coding style and other minor cleanups]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2013-12-17 11:26:42 +01:00