Commit Graph

462 Commits

Author SHA1 Message Date
Thierry Reding 97512ceafa Merge branch 'for-4.12/drivers' into for-next 2017-04-13 17:41:50 +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
Sven Van Asbroeck c40c461e19 pwm: pca9685: Fix GPIO-only operation
GPIO-only driver operation never clears the SLEEP bit, which can cause
the GPIOs to become unusable.

Example:
1. user requests first PWM  ->      driver clears SLEEP bit
2. user frees last PWM      ->      driver sets SLEEP bit
3. user requests GPIO
4. user switches GPIO on    ->      output does not turn on
                                    because SLEEP bit is set

Prevent this behaviour by letting the runtime PM framework control the
SLEEP bit. This will put the chip to SLEEP if no PWMs/GPIOs are exported
or in use.

Fixes: bccec89f0a ("Allow any of the 16 PWMs to be used as a GPIO")
Reported-by: Sven Van Asbroeck <TheSven73@googlemail.com>
Signed-off-by: Sven Van Asbroeck <TheSven73@googlemail.com>
Suggested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-13 17:35:01 +02:00
kbuild test robot 6db249db5e pwm: mediatek: Don't explicitly set .owner
drivers/pwm/pwm-mediatek.c:210:3-8: No need to set .owner here. The core will do it.

 Remove .owner field if calls are used which set it automatically

Generated by: scripts/coccinelle/api/platform_no_drv_owner.cocci

CC: John Crispin <john@phrozen.org>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-13 17:35:00 +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
John Crispin caf065f8fd pwm: Add MediaTek PWM support
This patch adds support for the PWM core found on current ARM base SoCs
made by MediaTek. This IP core supports 5 channels and has 2 operational
modes. There is the old mode, which is a classical PWM and the new mode
which allows the user to define bitmasks that get clocked out on the
pins. As the subsystem currently only supports PWM cores with the "old"
mode, we can safely ignore the "new" mode for now.

Signed-off-by: John Crispin <john@phrozen.org>
[thierry.reding@gmail.com: minor cleanups]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-06 17:45:04 +02:00
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
Boris Brezillon f9bb9da7c0 pwm: atmel-hlcdc: Implement the suspend/resume hooks
Implement the suspend/resume hooks to make sure the PWM device is
restored to a correct state after a suspend.

Signed-off-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
Boris Brezillon 2267517cd3 pwm: atmel-hlcdc: Convert to the atomic PWM API
Implement the ->apply() hook and drop the ->enable(), ->disable,
->set_polarity and ->config() ones.

Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Acked-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-06 16:12:52 +02:00
David Wu a900152b5c pwm: rockchip: State of PWM clock should synchronize with PWM enabled state
If the PWM was not enabled at U-Boot loader, PWM could not work for
clock always disabled at PWM driver. The PWM clock is enabled at
beginning of pwm_apply(), but disabled at end of pwm_apply().

If the PWM was enabled at U-Boot loader, PWM clock is always enabled
unless closed by ATF. The pwm-backlight might turn off the power at
early suspend, should disable PWM clock for saving power consume.

It is important to provide opportunity to enable/disable clock at PWM
driver, the PWM consumer should ensure correct order to call PWM enable
and disable, and PWM driver ensure state of PWM clock synchronized with
PWM enabled state.

Fixes: 2bf1c98aa5 ("pwm: rockchip: Add support for atomic update")
Cc: stable@vger.kernel.org
Signed-off-by: David Wu <david.wu@rock-chips.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-06 15:08:52 +02:00
Hans de Goede b997e3edca pwm: lpss: Set enable-bit before waiting for update-bit to go low
At least on cherrytrail, the update bit will never go low when the
enabled bit is not set.

This causes the backlight on my cube iwork8 air tablet to never turn on
again after being turned off because in the pwm_lpss_apply enable path
pwm_lpss_update will fail causing an error exit and the enable-bit to
never get set. Any following pwm_lpss_apply calls will fail the
pwm_lpss_is_updating check.

Since the docs say that the update bit should be set before the
enable-bit, split pwm_lpss_update into setting the update-bit and
pwm_lpss_wait_for_update, and move the pwm_lpss_wait_for_update call
in the enable path to after setting the enable-bit.

Fixes: 10d56a4 ("pwm: lpss: Avoid reconfiguring while UPDATE bit...")
Cc: Ilkka Koskinen <ilkka.koskinen@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-06 14:48:14 +02:00
Andy Shevchenko 3c1460e934 pwm: lpss: Split Tangier configuration
As a preparation for special treatment for Broxton we split Tangier
configuration.

Fixes: b89b4b7a3d ("pwm: lpss: pci: Enable PWM module on Intel Edison")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Tested-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-04-06 14:47:30 +02:00
Linus Torvalds 545b2820c4 pwm: Changes for v4.11-rc1
This set contains mostly fixes to existing drivers as well as cleanup of
 code that's not been in active use for a while.
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Merge tag 'pwm/for-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This set contains mostly fixes to existing drivers as well as cleanup
  of code that's not been in active use for a while"

* tag 'pwm/for-4.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (27 commits)
  acpi: lpss: call pwm_add_table() for BSW PWM device
  pwm: Try to load modules during pwm_get()
  pwm: Don't hold pwm_lookup_lock longer than necessary
  pwm: Make the PWM_POLARITY flag in DTB optional
  pwm: Print error messages with pr_err() instead of pr_debug()
  pwm: imx: Add polarity inversion support to i.MX's PWMv2
  pwm: imx: doc: Update imx-pwm.txt documentation entry
  pwm: imx: Remove redundant i.MX PWMv2 code
  pwm: imx: Provide atomic PWM support for i.MX PWMv2
  pwm: imx: Move PWMv2 wait for fifo slot code to a separate function
  pwm: imx: Move PWMv2 software reset code to a separate function
  pwm: imx: Rewrite v1 code to facilitate switch to atomic PWM
  pwm: imx: Add separate set of PWM ops for v1 and v2
  pwm: imx: Remove ipg clock and enable per clock when required
  pwm: lpss: Add Intel Gemini Lake PCI ID
  pwm: lpss: Do not export board infos for different PWM types
  pwm: lpss: Avoid reconfiguring while UPDATE bit is still enabled
  pwm: lpss: Switch to new atomic API
  pwm: lpss: Allow duty cycle to be 0
  pwm: lpss: Avoid potential overflow of base_unit
  ...
2017-03-01 09:46:02 -08:00
Thierry Reding 38b0a526ec Merge branch 'for-4.11/drivers' into for-next 2017-02-10 15:15:56 +01:00
Hans de Goede b526a31426 pwm: Try to load modules during pwm_get()
Add a module name string to the pwm_lookup struct and if specified try
to load the module using request_module() if pwmchip_find_by_name() is
unable to find the PWM chip.

This is a last resort to work around drivers that can't - and can't be
made to - deal with deferred probe.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
[thierry.reding@gmail.com: rename new macro, reword commit message]
[thierry.reding@gmail.com: add comment explaining use-case]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:36:42 +01:00
Hans de Goede 69efb3439c pwm: Don't hold pwm_lookup_lock longer than necessary
There is no need to hold pwm_lookup_lock after we're done with looping
over pwm_lookup_list, so release it earlier.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:19:26 +01:00
Lothar Wassmann 42883cbc08 pwm: Make the PWM_POLARITY flag in DTB optional
Change the PWM chip driver registration so that a chip driver that
supports polarity inversion can still be used with DTBs that don't
provide the polarity flag as part of the specifier.

This is done to provide polarity inversion support for the pwm-imx
driver without having to modify all existing DTS files.

Signed-off-by: Lothar Wassmann <LW@KARO-electronics.de>
Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Suggested-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:13:34 +01:00
Lothar Wassmann f2dafc0950 pwm: Print error messages with pr_err() instead of pr_debug()
Make the messages that are printed in case of fatal errors actually
visible to the user without having to recompile the driver with
debugging enabled.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:13:30 +01:00
Lukasz Majewski 326ed314fe pwm: imx: Add polarity inversion support to i.MX's PWMv2
With this patch the polarity settings for i.MX's PWMv2 is now supported
on top of atomic PWM setting

Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:13:07 +01:00
Lukasz Majewski 871985b154 pwm: imx: Remove redundant i.MX PWMv2 code
The code providing functionality surpassed by the atomic PWM is not
needed anymore and hence can be removed.

Suggested-by: Stefan Agner <stefan@agner.ch>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:12:59 +01:00
Lukasz Majewski 0ca1a11a1d pwm: imx: Provide atomic PWM support for i.MX PWMv2
This commit provides apply() callback implementation for i.MX's PWMv2.

Suggested-by: Stefan Agner <stefan@agner.ch>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:12:52 +01:00
Lukasz Majewski 73b1ff1f3e pwm: imx: Move PWMv2 wait for fifo slot code to a separate function
The code, which waits for fifo slot, has been extracted from
imx_pwm_config_v2 function and moved to new one - imx_pwm_wait_fifo_slot().

This change reduces the overall size of imx_pwm_config_v2() and prepares
it for atomic PWM operation.

Suggested-by: Stefan Agner <stefan@agner.ch>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:12:48 +01:00
Lukasz Majewski 970247a486 pwm: imx: Move PWMv2 software reset code to a separate function
The software reset code has been extracted from imx_pwm_config_v2 function
and moved to new one - imx_pwm_sw_reset().

This change reduces the overall size of imx_pwm_config_v2() and prepares
it for atomic PWM operation.

Suggested-by: Stefan Agner <stefan@agner.ch>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:12:46 +01:00
Lukasz Majewski b3c088fe02 pwm: imx: Rewrite v1 code to facilitate switch to atomic PWM
The code has been rewritten to remove "generic" calls to
imx_pwm_{enable|disable|config}.

Such approach would facilitate switch to atomic PWM (a.k.a ->apply())
implementation.

Suggested-by: Stefan Agner <stefan@agner.ch>
Suggested-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:12:42 +01:00
Lukasz Majewski 0038922954 pwm: imx: Add separate set of PWM ops for v1 and v2
This patch provides separate set of PWM operations utilized by i.MX's
v1 and v2 of the PWM hardware.

Signed-off-by: Lothar Waßmann <LW@KARO-electronics.de>
Signed-off-by: Bhuvanchandra DV <bhuvanchandra.dv@toradex.com>
Signed-off-by: Lukasz Majewski <l.majewski@majess.pl>
Acked-by: Shawn Guo <shawn.guo@linaro.org>
Reviewed-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:12:39 +01:00
Sascha Hauer 9fb27fac39 pwm: imx: Remove ipg clock and enable per clock when required
The use of the ipg clock was introduced with commit 7b27c160c6 ("pwm:
i.MX: fix clock lookup"). In the commit message it was claimed that the
ipg clock is enabled for register accesses. This is true for the
->config() callback, but not for the ->set_enable() callback. Given that
the ipg clock is not consistently enabled for all register accesses we
can assume that either it is not required at all or that the current
code does not work. Remove the ipg clock code for now so that it's no
longer in the way of refactoring the driver.

On the other hand, the i.MX 7 IP requires the peripheral clock to be
enabled before accessing its registers. Since ->config() can be called
when the PWM is disabled (in which case, the peripheral clock is also
disabled), we need to surround the imx->config() with
clk_prepare_enable(per_clk)/clk_disable_unprepare(per_clk) calls.

Note that the driver was working fine for the i.MX 7 IP so far because
the ipg and peripheral clock use the same hardware clock gate, which
guaranteed peripheral clock activation even when ->config() was called
when the PWM was disabled.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Philipp Zabel <p.zabel@pengutronix.de>
Reviewed-by: Stefan Agner <stefan@agner.ch>
Tested-by: Stefan Agner <stefan@agner.ch>
Reviewed-by: Boris Brezillon <boris.brezillon@free-electrons.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 09:12:18 +01:00
Mika Westerberg ae2520540c pwm: lpss: Add Intel Gemini Lake PCI ID
Intel Gemini Lake PWM is pretty much same as used in Intel Broxton. Add
this new PCI ID to the list of supported devices.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 08:17:18 +01:00
Andy Shevchenko 9900073cf5 pwm: lpss: Do not export board infos for different PWM types
The PWM LPSS probe drivers just pass a pointer to the exported board
info structures to pwm_lpss_probe() based on device PCI or ACPI ID.

In order to remove the knowledge of specific devices from library part of
the driver and reduce noise in exported namespace just duplicate the
board info structures and stop exporting them.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 08:16:55 +01:00
Ilkka Koskinen 10d56a4cb1 pwm: lpss: Avoid reconfiguring while UPDATE bit is still enabled
PWM Configuration register has SW_UPDATE bit that is set when a new
configuration is written to the register. The bit is automatically
cleared at the start of the next output cycle by the IP block.

If one writes a new configuration to the register while it still has
the bit enabled, PWM may freeze. That is, while one can still write
to the register, it won't have an effect. Thus, we try to sleep long
enough that the bit gets cleared and make sure the bit is not
enabled while we update the configuration.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Tested-by: Richard Griffiths <richard.a.griffiths@intel.com>
Signed-off-by: Ilkka Koskinen <ilkka.koskinen@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 08:15:12 +01:00
Andy Shevchenko b14e8ceff0 pwm: lpss: Switch to new atomic API
Instead of doing things separately, which is not so reliable on some platforms,
switch the driver to use new atomic API, i.e. ->apply() callback.

The change has been tested on Intel platforms such as Broxton, BayTrail, and
Merrifield.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 08:13:55 +01:00
Andy Shevchenko b5c050c719 pwm: lpss: Allow duty cycle to be 0
A duty cycle is represented by values [0..<period>] which reflects [0%..100%].
0% of the duty cycle means always off (logical "0") on output. Allow this in
the driver.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 08:13:39 +01:00
Andy Shevchenko 684309e504 pwm: lpss: Avoid potential overflow of base_unit
The resolution of base_unit is derived from base_unit_bits and thus must be
equal to (2^base_unit_bits - 1). Otherwise frequency and therefore base_unit
might potentially overflow.

Prevent the above by substracting 1 in all cases where base_unit_bits or
derivative is used.

Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-30 08:13:19 +01:00
Benjamin Gaignard 7edf736920 pwm: Add driver for STM32 plaftorm
This driver adds support for PWM driver on STM32 platform.
The SoC have multiple instances of the hardware IP and each
of them could have small differences: number of channels,
complementary output, auto reload register size...

version 9:
- fix commit message header
- remove one space MODULE_ALIAS

version 8:
- fix comments done by Thierry on version 7

version 6:
- change st,breakinput parameter to make it usuable for stm32f7 too.

version 4:
- detect at probe time hardware capabilities
- fix comments done on v2 and v3
- use PWM atomic ops

version 2:
- only keep one comptatible
- use DT parameters to discover hardware block configuration

Signed-off-by: Benjamin Gaignard <benjamin.gaignard@st.com>
Acked-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
2017-01-25 16:11:55 +00:00
Clemens Gruber 8d254a340e pwm: pca9685: Fix period change with same duty cycle
When first implementing support for changing the output frequency, an
optimization was added to continue the PWM after changing the prescaler
without having to reprogram the ON and OFF registers for the duty cycle,
in case the duty cycle stayed the same. This was flawed, because we
compared the absolute value of the duty cycle in nanoseconds instead of
the ratio to the period.

Fix the problem by removing the shortcut.

Fixes: 01ec847200 ("pwm-pca9685: Support changing the output frequency")
Cc: <stable@vger.kernel.org> # v4.3+
Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-20 07:43:22 +01:00
Bhumika Goyal b2ec9efc1f pwm: constify pwm_ops structures
Declare pwm_ops structures as const as they are only stored in the ops
field of a pwm_chip structure. This field is of type const struct pwm_ops
*, so pwm_ops structures having this property can be declared as const.
Done using Coccinelle:

@r1 disable optional_qualifier@
identifier i;
position p;
@@
static struct pwm_ops i@p={...};

@ok1@
identifier r1.i;
position p;
struct pxa_pwm_chip pwm;
struct bfin_pwm_chip bwm;
struct vt8500_chip vp;
struct imx_chip icp;
@@
(
pwm.chip.ops=&i@p
|
bwm.chip.ops=&i@p
|
vp.chip.ops=&i@p
|
icp.chip.ops=&i@p
)

@bad@
position p!={r1.p,ok1.p};
identifier r1.i;
@@
i@p

@depends on !bad disable optional_qualifier@
identifier r1.i;
@@
+const
struct pwm_ops i;

File size details:

   text	   data	    bss	    dec	    hex	filename
   1646	    328	      0	   1974	    7b6	drivers/pwm/pwm-imx.o
   1742	    224	      0	   1966	    7ae	drivers/pwm/pwm-imx.o

   1941	    296	      0	   2237	    8bd	drivers/pwm/pwm-pxa.o
   2037	    192	      0	   2229	    8b5	drivers/pwm/pwm-pxa.o

   1946	    296	      0	   2242	    8c2	drivers/pwm/pwm-vt8500.o
   2050	    192	      0	   2242	    8c2	drivers/pwm/pwm-vt8500.o

The drivers/pwm/pwm-bfin.o file did not compile.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-19 00:38:17 +01:00
Scott Branden 5bf22ff32e pwm: bcm-iproc: Update dependencies for compile-test
Add dependency on COMMON_CLK and allow COMPILE_TEST for broader compile
coverage. Default to Y for IPROC SoCs. This allows the driver to simply
be enabled by selecting PWM.

Signed-off-by: Scott Branden <scott.branden@broadcom.com>
Reviewed-by: Ray Jui <ray.jui@broadcom.com>
[thierry.reding@gmail.com: reword commit message]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-19 00:38:17 +01:00
Mika Westerberg bccec89f0a pwm: pca9685: Allow any of the 16 PWMs to be used as a GPIO
The PCA9685 controller has full on/off bit for each PWM channel. Setting
this bit bypasses the PWM control and the line works just as it would be a
GPIO. Furthermore in Intel Galileo it is actually used as GPIO output for
discreet muxes on the board.

This patch adds GPIO output only support for the driver so that we can
control the muxes on Galileo using standard GPIO interfaces available in
the kernel. GPIO and PWM functionality is exclusive so only one can be
active at a time on a single PWM channel.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-19 00:38:16 +01:00
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 fe2858c8c6 pwm: Remove pwm_can_sleep()
The last user of this function has been removed, so it is no longer
needed.

Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2017-01-04 09:39:52 +01:00
Linus Torvalds 57d64e6f5f pwm: Changes for v4.10-rc1
This is a very tiny pull request, with just a new driver for HiSilicon
 BVT SoCs and a cleanup for the Amlogic Meson driver.
 
 There are other patches on the list, but my timing was really bad this
 time and I ended up not having the time to look at them in enough detail
 to be comfortable merging them.
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Merge tag 'pwm/for-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm

Pull pwm updates from Thierry Reding:
 "This is a very tiny pull request, with just a new driver for HiSilicon
  BVT SoCs and a cleanup for the Amlogic Meson driver.

  There are other patches on the list, but my timing was really bad this
  time and I ended up not having the time to look at them in enough
  detail to be comfortable merging them"

* tag 'pwm/for-4.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
  pwm: Add PWM driver for HiSilicon BVT SOCs
  pwm: meson: Remove unneeded platform MODULE_ALIAS
2016-12-15 11:45:13 -08:00
yuanjian d09f008108 pwm: Add PWM driver for HiSilicon BVT SOCs
Add PWM driver for the PWM controller found on HiSilicon BVT SoCs such
as Hi3519V100, Hi3516CV300, etc. The PWM controller is primarily in
charge of controlling the P-Iris lens.

Reviewed-by: Jiancheng Xue <xuejiancheng@hisilicon.com>
Signed-off-by: Jian Yuan <yuanjian12@hisilicon.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-11-29 16:50:12 +01:00
Johan Hovold 0e1614ac84 pwm: Fix device reference leak
Make sure to drop the reference to the parent device taken by
class_find_device() after "unexporting" any children when deregistering
a PWM chip.

Fixes: 0733424c9b ("pwm: Unexport children before chip removal")
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-11-29 16:43:24 +01:00
Javier Martinez Canillas 58d5b69363 pwm: meson: Remove unneeded platform MODULE_ALIAS
The Amlogic Meson is a DT-only platform, which means the devices are
registered via OF and not using the legacy platform devices support.

So there's no need to have a MODULE_ALIAS("platform:meson-pwm") since
the reported uevent MODALIAS to user-space will always be the OF one.

Signed-off-by: Javier Martinez Canillas <javier@osg.samsung.com>
Acked-by: Kevin Hilman <khilman@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-10-21 09:12:41 +02:00
Axel Lin c699995663 pwm: meson: Add missing spin_lock_init()
The driver uses the spin_lock but does not initialize it. Fix it.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-10-21 09:10:11 +02:00
Thierry Reding dc8e6e1e8f Merge branch 'for-4.9/drivers' into for-next 2016-09-08 10:59:30 +02:00
Arnd Bergmann 2fbc487df6 pwm: meson: Handle unknown ID values
When building with -Wmaybe-uninitialized, we get a couple of harmless
warnings about three functions in this new driver that don't look
safe to the compiler:

drivers/pwm/pwm-meson.c: In function 'meson_pwm_get_state':
drivers/pwm/pwm-meson.c:355:26: error: 'mask' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/pwm/pwm-meson.c: In function 'meson_pwm_disable':
drivers/pwm/pwm-meson.c:263:13: error: 'enable' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/pwm/pwm-meson.c: In function 'meson_pwm_apply':
drivers/pwm/pwm-meson.c:231:13: error: 'clk_shift' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/pwm/pwm-meson.c:231:36: error: 'enable' may be used uninitialized in this function [-Werror=maybe-uninitialized]
drivers/pwm/pwm-meson.c:231:24: error: 'clk_enable' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Specifically, if we have a device with an ID other than 0 or 1,
this would result in undefined behavior. This is currently not
possible, but the compiler cannot be expected to know this.

This patch adds a 'default' clause to let the compiler know
what to do instead, which shuts up the warning and makes the
code slightly more resiliant in case it gets extended to other
identifiers.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Neil Armstrong <narmstrong@baylibre.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2016-09-08 10:58:33 +02:00