Commit Graph

21 Commits

Author SHA1 Message Date
Jernej Skrabec 5b090b430d pwm: sun4i: Add an optional probe for bus clock
H6 PWM core needs bus clock to be enabled in order to work.

Add an optional probe for it.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:48:19 +01:00
Clément Péron b8d74644f3 pwm: sun4i: Prefer "mod" clock to unnamed
New device tree bindings called the source clock of the module
"mod" when several clocks are defined.

Try to get a clock called "mod" if nothing is found try to get
an unnamed clock.

Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:48:05 +01:00
Jernej Skrabec a7fe985633 pwm: sun4i: Add an optional probe for reset line
H6 PWM core needs deasserted reset line in order to work.

Add an optional probe for it.

Signed-off-by: Jernej Skrabec <jernej.skrabec@siol.net>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Clément Péron <peron.clem@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-01-08 12:47:26 +01:00
Ondrej Jirman 50cc7e3e4f pwm: sun4i: Fix incorrect calculation of duty_cycle/period
Since 5.4-rc1, pwm_apply_state calls ->get_state after ->apply
if available, and this revealed an issue with integer precision
when calculating duty_cycle and period for the currently set
state in ->get_state callback.

This issue manifested in broken backlight on several Allwinner
based devices.

Previously this worked, because ->apply updated the passed state
directly.

Fixes: deb9c462f4 ("pwm: sun4i: Don't update the state for the caller of pwm_apply_state")
Signed-off-by: Ondrej Jirman <megous@megous.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:50:02 +02:00
Colin Ian King 1b98ad3b3b pwm: sun4i: Drop redundant assignment to variable pval
Variable pval is being assigned a value that is never read. The
assignment is redundant and hence can be removed.

Addresses-Coverity: ("Unused value")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-10-21 16:49:58 +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
Uwe Kleine-König deb9c462f4 pwm: sun4i: Don't update the state for the caller of pwm_apply_state()
The pwm-sun4i driver is one of only three PWM drivers which updates the
state for the caller of pwm_apply_state(). This might have surprising
results if the caller reuses the values expecting them to still
represent the same state.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21 01:48:55 +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
Andre Przywara 7b4c7c567d pwm: sun4i: Simplify controller mapping
At the moment we assign our supported compatible strings to a respective
instance of our sun4i_pwm_data structure, even though some of them
are the same.
To avoid further clutter, split out the three different combinations of
features we have at the moment and name them accordingly.
This should make it more obvious which compatible string to use for new
SoCs.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-03-28 01:12:12 +02:00
Andre Przywara 6a89bb6cc0 pwm: sun4i: Drop unused .has_rdy member
Commit a054c4d684 ("pwm: sun4i: Drop legacy callbacks") dropped the
only user of the .has_rdy member in our sun4i_pwm_data struct.
Consequently we don't need to store this anymore for the various SoCs,
which paves the way for further simplifications.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Maxime Ripard <maxime.ripard@bootlin.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-03-28 01:11:53 +02:00
Alexandre Belloni 989ae7a5b2 pwm: sun4i: Properly check current state
Correctly extract the prescaler value from CTRL_REG before comparing it
to PWM_PRESCAL_MASK.

Also, check that both PWM_CLK_GATING and PWM_EN to ensure the PWM is
enabled instead of relying on only one of those.

Fixes: 93e0dfb2c5 ("pwm: sun4i: Improve hardware read out")
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2018-03-28 01:07:57 +02:00
Corentin Labbe df4f6e8c9f pwm: sunxi: Use of_device_get_match_data()
The usage of of_device_get_match_data reduce the code size a bit.
Furthermore, it prevents an improbable dereference when
of_match_device() returns NULL.

Signed-off-by: Corentin Labbe <clabbe.montjoie@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-11-15 10:56:55 +01:00
Alexandre Belloni a054c4d684 pwm: sun4i: Drop legacy callbacks
Remove the legacy callbacks .enable(), .disable(), .set_polarity() and
.config().

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-07-06 09:05:21 +02:00
Alexandre Belloni c32c5c50d4 pwm: sun4i: Switch to atomic PWM
Switch the driver to atomic PWM. This makes it easier to wait a proper
amount of time when changing the duty cycle before disabling the channel
(main use case is switching the duty cycle to 0 before disabling).

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-07-06 09:05:21 +02:00
Alexandre Belloni 93e0dfb2c5 pwm: sun4i: Improve hardware read out
Implement .get_state instead of only reading the polarity at probe time.
This allows to get the proper state, period and duty cycle.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-07-06 09:05:17 +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
Milo Kim 42ddcf4f9e pwm: sunxi: Add H3 support
H3 PWM controller has same register layout as sun4i driver, so it works
by adding H3 specific data.

Cc: Thierry Reding <thierry.reding@gmail.com>
Cc: Rob Herring <robh+dt@kernel.org>
Cc: Maxime Ripard <maxime.ripard@free-electrons.com>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: linux-pwm@vger.kernel.org
Cc: devicetree@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Milo Kim <woogyom.kim@gmail.com>
Acked-by: Chen-Yu Tsai <wens@csie.org>
Reviewed-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:55:05 +02:00
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
Olliver Schinagl 5dcd7b42f1 pwm: sunxi: Fix whitespace issue
This patch changes no code, it just fixes the whitespacing. Operators
should be separated from operands by a single space.

Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-10 13:06:47 +01:00
Hans de Goede f6649f7ad8 pwm: sun4i: Add support for PWM controller on sun5i SoCs
The PWM controller on sun5i SoCs is identical to the one found on sun7i
SoCs. On the A13 package only one of the 2 pins is routed to the outside,
so only advertise one PWM channel there.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-11-10 13:06:41 +01:00
Alexandre Belloni 09853ce7bc pwm: Add Allwinner SoC support
This adds a generic PWM framework driver for the PWM controller
found on Allwinner SoCs.

Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Acked-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2015-01-30 12:16:01 +01:00