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This allows to simplify all drivers that use three pwm-cells.
The only ugly side effect is that if a driver specified of_pwm_n_cells = 2
it suddenly supports device trees that use #pwm-cells = <3>. This however
isn't a bad thing because the driver doesn't need explicit support for
three cells as the core handles all the details. Also there is no such
in-tree driver.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Since the previous commit the latter function can do everything that the
former does. So simplify accordingly.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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The two functions of_pwm_simple_xlate() and of_pwm_xlate_with_flags()
are quite similar. of_pwm_simple_xlate() only supports two-cell PWM
specifiers while of_pwm_xlate_with_flags() only supports PWM specifiers
with 3 or more cells. The latter can easily be modified to behave
identically to of_pwm_simple_xlate() for two-cell PWM specifiers. This
is implemented here and allows to drop of_pwm_simple_xlate() in the next
commit.
There is a small detail that is different now in the two-cell specifier
case in of_pwm_xlate_with_flags(): pwm->args.polarity is unconditionally
initialized to PWM_POLARITY_NORMAL in the latter. I didn't find a case
where this matters and doing that explicitly is the more robust
approach.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[thierry.reding@gmail.com: fix up checkpatch warnings]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
Pull pwm updates from Thierry Reding:
"This adds support for the PWM controller found on Toshiba Visconti
SoCs and converts a couple of drivers to the atomic API.
There's also a bunch of cleanups and minor fixes across the board"
* tag 'pwm/for-5.13-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (35 commits)
pwm: Reword docs about pwm_apply_state()
pwm: atmel: Improve duty cycle calculation in .apply()
pwm: atmel: Fix duty cycle calculation in .get_state()
pwm: visconti: Add Toshiba Visconti SoC PWM support
dt-bindings: pwm: Add bindings for Toshiba Visconti PWM Controller
arm64: dts: rockchip: Remove clock-names from PWM nodes
ARM: dts: rockchip: Remove clock-names from PWM nodes
dt-bindings: pwm: rockchip: Add more compatible strings
dt-bindings: pwm: Convert pwm-rockchip.txt to YAML
pwm: mediatek: Remove unused function
pwm: pca9685: Improve runtime PM behavior
pwm: pca9685: Support hardware readout
pwm: pca9685: Switch to atomic API
pwm: lpss: Don't modify HW state in .remove callback
pwm: sti: Free resources only after pwmchip_remove()
pwm: sti: Don't modify HW state in .remove callback
pwm: lpc3200: Don't modify HW state in .remove callback
pwm: lpc18xx-sct: Free resources only after pwmchip_remove()
pwm: bcm-kona: Don't modify HW state in .remove callback
pwm: bcm2835: Free resources only after pwmchip_remove()
...
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git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd
Pull MFD updates from Lee Jones:
"Core Framework:
- Add support for Software Nodes to MFD Core
- Remove support for Device Properties from MFD Core
- Use standard APIs in MFD Core
New Drivers:
- Add support for ROHM BD9576MUF and BD9573MUF PMICs
- Add support for Netronix Embedded Controller, PWM and RTC
- Add support for Actions Semi ATC260x PMICs and OnKey
New Device Support:
- Add support for DG1 PCIe Graphics Card to Intel PMT
- Add support for ROHM BD71815 PMIC to ROHM BD71828
- Add support for Tolino Shine 2 HD to Netronix Embedded Controller
- Add support for AX10 BMC Secure Updates to Intel M10 BMC
Removed Device Support:
- Remove Arizona Extcon support from MFD
- Remove ST-E AB8500 Power Supply code from MFD
- Remove AB3100 altogether
New Functionality:
- Add support for SMBus and I2C modes to Dialog DA9063
- Switch to using Software Nodes in Intel (various)
New/converted Device Tree bindings:
- rohm bd71815-pmic, rohm bd9576-pmic, netronix ntxec, actions
atc260x, ricoh rn5t618, qcom pm8xxx
- Fix-ups:
- Fix error handling/path; intel_pmt
- Simplify code; rohm-bd718x7, ab8500-core, intel-m10-bmc
- Trivial clean-ups (reordering, spelling); rohm-generic, rn5t618,
max8997
- Use correct data-type; db8500-prcmu
- Remove superfluous code; lp87565, intel_quark_i2c_gpi, lpc_sch, twl
- Use generic APIs/defines; lm3533-core, intel_quark_i2c_gpio
- Regmap related fix-ups; intel-m10-bmc, sec-core
- Reorder resource freeing during remove; intel_quark_i2c_gpio
- Make table indexing more robust; intel_quark_i2c_gpio
- Fix reference imbalances; arizona-irq
- Staticify and (un)constify things; arizona-spi, stmpe, ene-kb3930,
intel-lpss-acpi, intel-lpss-pci, atc260x-i2c, intel_quark_i2c_gpio
Bug Fixes:
- Fix incorrect (register) values; intel-m10-bmc
- Kconfig related fixes; ABX500_CORE
- Do not clear the Auto Reload Register; stm32-timers"
* tag 'mfd-next-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/lee/mfd: (84 commits)
mfd: intel-m10-bmc: Add support for MAX10 BMC Secure Updates
Revert "mfd: max8997: Add of_compatible to Extcon and Charger mfd_cell"
mfd: twl: Remove unused inline function twl4030charger_usb_en()
dt-bindings: mfd: Convert pm8xxx bindings to yaml
dt-bindings: mfd: Add compatible for pmk8350 rtc
i2c: designware: Get rid of legacy platform data
mfd: intel_quark_i2c_gpio: Convert I²C to use software nodes
mfd: lpc_sch: Partially revert "Add support for Intel Quark X1000"
mfd: arizona: Fix rumtime PM imbalance on error
mfd: max8997: Replace 8998 with 8997
mfd: core: Use acpi_find_child_device() for child devices lookup
mfd: intel_quark_i2c_gpio: Don't play dirty trick with const
mfd: intel_quark_i2c_gpio: Enable MSI interrupt
mfd: intel_quark_i2c_gpio: Reuse BAR definitions for MFD cell indexing
mfd: ntxec: Support for EC in Tolino Shine 2 HD
mfd: stm32-timers: Avoid clearing auto reload register
mfd: intel_quark_i2c_gpio: Replace I²C speeds with descriptive definitions
mfd: intel_quark_i2c_gpio: Remove unused struct device member
mfd: intel_quark_i2c_gpio: Unregister resources in reversed order
mfd: Kconfig: ABX500_CORE should depend on ARCH_U8500
...
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In the calculation of the register value determining the duty cycle the
requested period is used instead of the actually implemented period which
results in suboptimal settings.
The following example assumes an input clock of 133333333 Hz on one of
the SoCs with 16 bit period.
When the following state is to be applied:
.period = 414727681
.duty_cycle = 652806
the following register values used to be calculated:
PRES = 10
CPRD = 54000
CDTY = 53916
which yields an actual duty cycle of a bit more than 645120 ns.
The setting
PRES = 10
CPRD = 54000
CDTY = 53915
however yields a duty of 652800 ns which is between the current result
and the requested value and so is a better approximation.
The reason for this error is that for the calculation of CDTY the
requested period was used instead of the actually implemented one.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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The CDTY register contains the number of inactive cycles. .apply() does
this correctly, however .get_state() got this wrong.
Fixes: 651b510a74d4 ("pwm: atmel: Implement .get_state()")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Add driver for the PWM controller on Toshiba Visconti ARM SoC.
Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
[thierry.reding@gmail.com: fix up a couple of checkpatch warnings]
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Fix the following clang warning:
drivers/pwm/pwm-mediatek.c:110:19: warning: unused function
'pwm_mediatek_readl' [-Wunused-function].
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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The chip does not come out of POR in active state but in sleep state.
To be sure (in case the bootloader woke it up) we force it to sleep in
probe.
If runtime PM is disabled, we instead wake the chip in .probe and put it
to sleep in .remove.
Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Implement .get_state to read-out the current hardware state.
The hardware readout may return slightly different values than those
that were set in apply due to the limited range of possible prescale and
counter register values.
Also note that although the datasheet mentions 200 Hz as default
frequency when using the internal 25 MHz oscillator, the calculated
period from the default prescaler register setting of 30 is 5079040ns.
Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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The switch to the atomic API goes hand in hand with a few fixes to
previously experienced issues:
- The duty cycle is no longer lost after disable/enable (previously the
OFF registers were cleared in disable and the user was required to
call config to restore the duty cycle settings)
- If one sets a period resulting in the same prescale register value,
the sleep and write to the register is now skipped
- Previously, only the full ON bit was toggled in GPIO mode (and full
OFF cleared if set to high), which could result in both full OFF and
full ON not being set and on=0, off=0, which is not allowed according
to the datasheet
- The OFF registers were reset to 0 in probe, which could lead to the
forbidden on=0, off=0. Fixed by resetting to POR default (full OFF)
Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.
So drop the hardware modification from the .remove() callback.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Before pwmchip_remove() returns the PWM is expected to be functional. So
remove the pwmchip before disabling the clocks.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.
So drop the hardware modification from the .remove() callback.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing). Also if disabling an enabled PWM was the right thing to do,
this should better be done in the framework instead of in each low level
driver.
So drop the hardware modification from the .remove() callback.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Before pwmchip_remove() returns the PWM is expected to be functional. So
remove the pwmchip before disabling the clock.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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A consumer is expected to disable a PWM before calling pwm_put(). And if
they didn't there is hopefully a good reason (or the consumer needs
fixing.) Also if disabling an enabled PWM was the right thing to do, this
should better be done in the framework instead of in each low level driver.
So drop the hardware modification from the .remove() callback.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Before pwmchip_remove() returns the PWM is expected to be functional. So
remove the pwmchip before disabling the clock.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Before pwmchip_remove() returns the PWM is expected to be functional. So
remove the pwmchip before disabling the clock.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Before pwmchip_remove() returns the PWM is expected to be functional. So
remove the pwmchip before disabling the clock.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Adds support to control the PWM bus available in official Raspberry Pi
PoE HAT. Only RPi's co-processor has access to it, so commands have to
be sent through RPi's firmware mailbox interface.
Signed-off-by: Nicolas Saenz Julienne <nsaenzjulienne@suse.de>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
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pwmchip_add() only calls pwmchip_add_with_polarity() and nothing else. All
other users of pwmchip_add_with_polarity() are gone. So drop
pwmchip_add_with_polarity() and move the code instead to pwmchip_add().
The initial assignment to pwm->state.polarity is dropped. In every correct
usage of the PWM API this value is overwritten later anyhow.
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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The only side effect of this change is that pwm->state.polarity is
initialized to PWM_POLARITY_NORMAL instead of PWM_POLARITY_INVERSED.
However all other members of pwm->state are uninitialized and consumers
are expected to provide the right polarity (either by setting it explicitly
or by using a helper like pwm_init_state() that overwrites .polarity
anyhow with a value independent of the initial value).
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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The only side effect of this change is that pwm->state.polarity is
initialized to PWM_POLARITY_NORMAL instead of PWM_POLARITY_INVERSED.
However all other members of pwm->state are uninitialized and consumers
are expected to provide the right polarity (either by setting it explicitly
or by using a helper like pwm_init_state() that overwrites .polarity
anyhow with a value independent of the initial value).
The eventual goal is to remove pwmchip_add_with_polarity() and so simplify
the data flow in the PWM core.
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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The driver only supports normal polarity and so should refuse requests
for inversed polarity.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Enric Balletbo i Serra <enric.balletbo@collabora.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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The driver only supports normal polarity and so should refuse requests
for inversed polarity.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Chunyan Zhang <zhang.lyra@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Otherwise the PWM stops working before the PWM core and its consumers
are aware the device is going away.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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This is just pushing down the core's compat code down into the driver using
the legacy callback nearly unchanged. The call to .enable() was just
dropped from .config() because .apply() calls it unconditionally.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Since commit 2b1c1a5d5148 ("pwm: Use -EINVAL for unsupported polarity")
all drivers implementing the apply callback are unified to return
-EINVAL if an unsupported polarity is requested. Do the same in the
compat code for old-style drivers.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Since commit 5e5da1e9fbee ("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>
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There is no need to split the dev_err() call in three lines.
Use a single line to improve readability.
Signed-off-by: Fabio Estevam <festevam@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply().
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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With an input clk rate bigger than 2000000000, scaler would have been
zero which then would have resulted in a division by zero.
Also the originally implemented algorithm divided by the result of a
division. This nearly always looses precision. Consider a requested period
of 1000000 ns. With an input clock frequency of 32786885 Hz the hardware
was configured with an actual period of 983869.007 ns (PERIOD = 32258)
while the hardware can provide 1000003.508 ns (PERIOD = 32787).
And note if the input clock frequency was 32786886 Hz instead, the hardware
was configured to 1016656.477 ns (PERIOD = 33333) while the optimal
setting results in 1000003.477 ns (PERIOD = 32787).
This patch implements proper range checking and only divides once for
the calculation of period (and similar for duty_cycle).
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Tested-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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The Netronix EC provides a PWM output which is used for the backlight
on some ebook readers. This patches adds a driver for the PWM output.
The .get_state callback is not implemented, because the PWM state can't
be read back from the hardware.
Signed-off-by: Jonathan Neuschäfer <j.neuschaefer@gmx.net>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Thierry Reding <thierry.reding@gmail.com>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
Pull pwm updates from Thierry Reding:
"The ZTE ZX platform is being removed, so the PWM driver is no longer
needed and removed as well.
Other than that this contains a small set of fixes and cleanups across
a couple of drivers"
* tag 'pwm/for-5.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm:
pwm: lpc18xx-sct: remove unneeded semicolon
pwm: iqs620a: Correct a stale state variable
pwm: iqs620a: Fix overflow and optimize calculations
pwm: rockchip: Enable clock before calling clk_get_rate()
pwm: rockchip: Eliminate potential race condition when probing
pwm: rockchip: Replace "bus clk" with "PWM clk"
pwm: rockchip: rockchip_pwm_probe(): Remove superfluous clk_unprepare()
pwm: rockchip: Enable APB clock during register access while probing
pwm: Remove ZTE ZX driver
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Eliminate the following coccicheck warning:
./drivers/pwm/pwm-lpc18xx-sct.c:292:2-3: Unneeded semicolon
Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Yang Li <yang.lee@linux.alibaba.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Vladimir Zapolskiy <vz@mleia.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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If duty cycle is first set to a value that is sufficiently high to
enable the output (e.g. 10000 ns) but then lowered to a value that
is quantized to zero (e.g. 1000 ns), the output is disabled as the
device cannot drive a constant zero (as expected).
However if the device is later re-initialized due to watchdog bite,
the output is re-enabled at the next-to-last duty cycle (10000 ns).
This is because the iqs620_pwm->out_en flag unconditionally tracks
state->enabled instead of what was actually written to the device.
To solve this problem, use one state variable that encodes all 257
states of the output (duty_scale) with 0 representing tri-state, 1
representing the minimum available duty cycle and 256 representing
100% duty cycle.
Signed-off-by: Jeff LaBundy <jeff@labundy.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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If state->duty_cycle is 0x100000000000000, the previous calculation of
duty_scale overflows and yields a duty cycle ratio of 0% instead of
100%. Fix this by clamping the requested duty cycle to the maximal
possible duty cycle first. This way it is possible to use a native
integer division instead of a (depending on the architecture) more
expensive 64bit division.
With this change in place duty_scale cannot be bigger than 256 which
allows to simplify the calculation of duty_val.
Fixes: 6f0841a8197b ("pwm: Add support for Azoteq IQS620A PWM generator")
Tested-by: Jeff LaBundy <jeff@labundy.com>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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The documentation for clk_get_rate() in include/linux/clk.h states the
function's result is valid only for a clock source that has been
enabled. However, the Rockchip PWM driver uses this function in two places
to query the rate of a clock without first ensuring it is enabled.
Fix this by modifying rockchip_pwm_get_state() and rockchip_pwm_apply() so
they enable a device's PWM clock before querying its rate (in the latter
case, the querying is actually done in rockchip_pwm_config()) and disable
the clock again before returning.
Reported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Simon South <simon@simonsouth.net>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Commit 48cf973cae33 ("pwm: rockchip: Avoid glitches on already running
PWMs") introduced a potential race condition in rockchip_pwm_probe(): A
consumer could enable an inactive PWM, or disable a running one, between
rockchip_pwm_probe() registering the device via pwmchip_add() and checking
whether it is enabled (to determine whether it was started by a
bootloader). This could result in a device's PWM clock being either enabled
once more than necessary, potentially causing it to continue running when
no longer needed, or disabled once more than necessary, producing a warning
from the kernel.
Eliminate these possibilities by modifying rockchip_pwm_probe() so it
checks whether a device is enabled before registering it rather than after.
Fixes: 48cf973cae33 ("pwm: rockchip: Avoid glitches on already running PWMs")
Reported-by: Trent Piepho <tpiepho@gmail.com>
Signed-off-by: Simon South <simon@simonsouth.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Clarify the Rockchip PWM driver's error messages by referring to the clock
that operates a PWM device as the "PWM" clock, matching its name in the
device tree, rather than the "bus" clock (which is especially misleading in
the case of devices that also use a separate clock for bus access).
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Simon South <simon@simonsouth.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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If rockchip_pwm_probe() fails to register a PWM device it calls
clk_unprepare() for the device's PWM clock, without having first disabled
the clock and before jumping to an error handler that also unprepares
it. This is likely to produce warnings from the kernel about the clock
being unprepared when it is still enabled, and then being unprepared when
it has already been unprepared.
Prevent these warnings by removing this unnecessary call to
clk_unprepare().
Fixes: 48cf973cae33 ("pwm: rockchip: Avoid glitches on already running PWMs")
Signed-off-by: Simon South <simon@simonsouth.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Commit 457f74abbed0 ("pwm: rockchip: Keep enabled PWMs running while
probing") modified rockchip_pwm_probe() to access a PWM device's registers
directly to check whether or not the device is enabled, but did not also
change the function so it first enables the device's APB clock to be
certain the device can respond. This risks hanging the kernel on systems
with PWM devices that use more than a single clock.
Avoid this by enabling the device's APB clock before accessing its
registers (and disabling the clock when register access is complete).
Fixes: 457f74abbed0 ("pwm: rockchip: Keep enabled PWMs running while probing")
Reported-by: Thierry Reding <thierry.reding@gmail.com>
Suggested-by: Trent Piepho <tpiepho@gmail.com>
Signed-off-by: Simon South <simon@simonsouth.net>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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The ZTE ZX platform is getting removed, so this driver is no longer
needed.
Cc: Jun Nie <jun.nie@linaro.org>
Cc: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm
Pull pwm updates from Thierry Reding:
"This is a fairly big release cycle from the PWM framework's point of
view.
There's a large patcheset here which converts drivers to use the new
devm_platform_ioremap_resource() helper and a bunch of minor fixes to
existing drivers. Some of the existing drivers also add support for
more hardware, such as Atmel SAMA 5D2 and Mediatek MT8183.
Finally there's a couple of new drivers for Intel Keem Bay and LGM
SoCs as well as the DesignWare PWM controller"
* tag 'pwm/for-5.11-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: (66 commits)
pwm: sun4i: Remove erroneous else branch
pwm: sl28cpld: Set driver data before registering the PWM chip
pwm: Remove unused function pwmchip_add_inversed()
pwm: imx27: Fix overflow for bigger periods
pwm: bcm2835: Support apply function for atomic configuration
pwm: keembay: Fix build failure with -Os
pwm: core: Use octal permission
pwm: lpss: Make compilable with COMPILE_TEST
pwm: Fix dependencies on HAS_IOMEM
pwm: Use -EINVAL for unsupported polarity
pwm: sti: Remove unnecessary blank line
pwm: sti: Avoid conditional gotos
pwm: Add PWM fan controller driver for LGM SoC
Add DT bindings YAML schema for PWM fan controller of LGM SoC
pwm: Add DesignWare PWM Controller Driver
dt-bindings: pwm: mtk-disp: add MT8167 SoC binding
pwm: mediatek: Add MT8183 SoC support
pwm: mediatek: Always use bus clock
dt-bindings: pwm: pwm-mediatek: Add documentation for MT8183 SoC
pwm: Add PWM driver for Intel Keem Bay
...
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Commit d3817a647059 ("pwm: sun4i: Remove redundant needs_delay") changed
the logic of an else branch so that the PWM_EN and PWM_CLK_GATING bits
are now cleared if the PWM is to be disabled, whereas previously the
condition was always false, and hence the branch never got executed.
This code is reported causing backlight issues on boards based on the
Allwinner A20 SoC. Fix this by removing the else branch, which restores
the behaviour prior to the offending commit.
Note that the PWM_EN and PWM_CLK_GATING bits still get cleared later in
sun4i_pwm_apply() if the PWM is to be disabled.
Fixes: d3817a647059 ("pwm: sun4i: Remove redundant needs_delay")
Reported-by: Taras Galchenko <tpgalchenko@gmail.com>
Suggested-by: Taras Galchenko <tpgalchenko@gmail.com>
Tested-by: Taras Galchenko <tpgalchenko@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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It is good practice to set the driver data before registering a device
with a subsystem because the subsystem or the driver core may call back
into the driver implementation. This is not currently an issue, but to
prevent future changes from causing this to break unexpectedly, make
sure that the driver data is set before the PWM chip registration.
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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The second parameter of do_div is an u32 and NSEC_PER_SEC * prescale
overflows this for bigger periods. Assuming the usual pwm input clk rate
of 66 MHz this happens starting at requested period > 606060 ns.
Splitting the division into two operations doesn't loose any precision.
It doesn't need to be feared that c / NSEC_PER_SEC doesn't fit into the
unsigned long variable "duty_cycles" because in this case the assignment
above to period_cycles would already have been overflowing as
period >= duty_cycle and then the calculation is moot anyhow.
Fixes: aef1a3799b5c ("pwm: imx27: Fix rounding behavior")
Signed-off-by: Uwe Kleine-König <uwe@kleine-koenig.org>
Tested-by: Johannes Pointner <johannes.pointner@br-automation.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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Use the newer .apply function of pwm_ops instead of .config, .enable,
.disable and .set_polarity. This guarantees atomic changes of the pwm
controller configuration. It also reduces the size of the driver.
Since now period is a 64 bit value, add an extra check to reject periods
that exceed the possible max value for the 32 bit register.
This has been tested on a Raspberry PI 4.
Signed-off-by: Lino Sanfilippo <LinoSanfilippo@gmx.de>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
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