Dividing by the result of a division looses precision because the result is
rounded twice. E.g. with clk_rate = 48000000 and period = 32760033 the
following numbers result:

	rate = pc->clk_rate >> PWM_DUTY_WIDTH = 187500
	hz = DIV_ROUND_CLOSEST_ULL(100ULL * NSEC_PER_SEC, period_ns) = 3052
	rate = DIV_ROUND_CLOSEST_ULL(100ULL * rate, hz) = 6144

The exact result would be 6142.5061875 and (apart from rounding) this is
found by using a single division. As a side effect is also a tad
cheaper to calculate.

Also using clk_rate >> PWM_DUTY_WIDTH looses precision. Consider for
example clk_rate = 47999999 and period = 106667:

	mul_u64_u64_div_u64(pc->clk_rate >> PWM_DUTY_WIDTH, period_ns,
			    NSEC_PER_SEC) = 19

	mul_u64_u64_div_u64(pc->clk_rate, period_ns,
			    NSEC_PER_SEC << PWM_DUTY_WIDTH) = 20

(The exact result is 20.000062083332033.)

With this optimizations also switch from round-closest to round-down for
the period calculation. Given that the calculations were non-optimal for
quite some time now with variations in both directions which nobody
reported as a problem, this is the opportunity to align the driver's
behavior to the requirements of new drivers. This has several upsides:

 - Implementation is easier as there are no round-nearest variants of
   mul_u64_u64_div_u64().
 - Requests for too small periods are now consistently refused. This was
   kind of arbitrary before, where period_ns < min_period_ns was
   refused, but in some cases min_period_ns isn't actually implementable
   and then values between min_period_ns and the actual minimum were
   rounded up to the actual minimum.

Note that the duty_cycle calculation isn't using the usual round-down
approach yet.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Dividing by the result of a division looses precision. Consider for example
clk_rate = 33000000 and period_ns = 500001. Then

	clk_rate / (NSEC_PER_SEC / period_ns)

has the exact value 16500.033, but in C this evaluates to 16508. It gets
worse for even bigger values of period_ns, so with period_ns = 500000001,
the exact result is 16500000.033 while in C we get 33000000.

For that reason use

	clk_rate * period_ns / NSEC_PER_SEC

instead which doesn't suffer from this problem. To ensure this doesn't
overflow add a safeguard check for clk_rate.

Note that duty > period can never happen, so the respective check can be
dropped.

Incidentally this fixes a division by zero if period_ns > NSEC_PER_SEC.
Another side effect is that values bigger than INT_MAX for period and
duty_cyle are not wrongly discarded any more.

Fixes: 99b82abb ("pwm: Add Renesas TPU PWM driver")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

The newly computed register values are intended to exactly match the
previously computed values. The main improvement is that the prescaler
is computed without a loop that involves two divisions in each step.
This uses the fact, that prescalers[i] = 1 << (2 * i).

Assuming a moderately smart compiler, the needed number of divisions for
the case where the requested period is too big, is reduced from 5 to 2.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

The driver used "pwm" for struct tpu_pwm_device pointers. This name is
usually only used for struct pwm_device pointers which this driver calls
"_pwm". So rename to the driver data pointers to "tpd" which then allows
to drop the underscore from "_pwm".
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply().

As pwm->state might not be updated in tpu_pwm_apply() before calling
tpu_pwm_config(), an additional parameter is needed for tpu_pwm_config()
to not change the implemented logic.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

This simplifies an error path in .probe() and allows to drop the .remove()
function.
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

The added benefit is that the error code is mentioned in the error message
and its usage is a bit more compact than open coding it. This also
improves behaviour in case devm_clk_get() returns -EPROBE_DEFER.

While touching this code, consistently start error messages with upper
case.
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply().

The size check for state->period is moved to .apply() to make sure that
the values of state->duty_cycle and state->period are passed to
pwm_samsung_config without change while they are discarded to int.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Use if and else instead of if(A) and if (!A).
Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Add interrupts property of pwm for MediaTek MT8192 SoC.
Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Add dt-binding documentation of pwm for MediaTek MT8186 SoC.
Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Add dt-binding documentation of pwm for MediaTek MT8195 SoC.
Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Add dt-binding documentation of pwm for MediaTek MT8192 SoC.
Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Convert pwm-mtk-disp.txt to mediatek,pwm-disp.yaml format as suggested
by maintainer.
Signed-off-by: Xinlei Lee <xinlei.lee@mediatek.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Miles Chen <miles.chen@mediatek.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

To eventually get rid of all legacy drivers convert this driver to the
modern world implementing .apply().

This fixes a small issue in clps711x_get_duty() en passant: the
multiplication v * 0xf might have overflown.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

The reg member of struct raspberrypi_pwm_prop is a little endian 32 bit
quantity. Explicitly convert the (native endian) value to little endian
on assignment as is already done in raspberrypi_pwm_set_property().

This fixes the following sparse warning:

	drivers/pwm/pwm-raspberrypi-poe.c:69:24: warning: incorrect type in initializer (different base types)
	drivers/pwm/pwm-raspberrypi-poe.c:69:24:    expected restricted __le32 [usertype] reg
	drivers/pwm/pwm-raspberrypi-poe.c:69:24:    got unsigned int [usertype] reg

Fixes: 79caa362 ("pwm: Add Raspberry Pi Firmware based PWM bus")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

The array atmel_tcb_divisors is not supposed to be used outside of the
driver, so make it static.

This fixes a sparse warning:

	drivers/pwm/pwm-atmel-tcb.c:64:10: warning: symbol 'atmel_tcb_divisors' was not declared. Should it be static?
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

pwmchip_add() unconditionally assigns the base ID dynamically. Commit
f9a8ee8c ("pwm: Always allocate PWM chip base ID dynamically")
dropped all base assignment from drivers under drivers/pwm/. It missed
this driver. Fix that.

Fixes: f9a8ee8c ("pwm: Always allocate PWM chip base ID dynamically")
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

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>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

The hardware only supports periods <= 1.6 ms and if a bigger period is
requested it is clamped to 1.6 ms. In this case duty_cycle might be bigger
than 1.6 ms and then the duty cycle register is written with a value
bigger than LP3943_MAX_DUTY. So clamp duty_cycle accordingly.

Fixes: af66b3c0 ("pwm: Add LP3943 PWM driver")
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Add Sunplus SoC SP7021 PWM Driver
Signed-off-by: Hammer Hsieh <hammerh0314@gmail.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Add bindings doc for Sunplus SoC SP7021 PWM Driver
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Signed-off-by: Hammer Hsieh <hammerh0314@gmail.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Add compatible strings list for SAMA7G5.
Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Convert PWM binding for Atmel/Microchip SoCs to Device Tree Schema
format.
Signed-off-by: Sergiu Moga <sergiu.moga@microchip.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@canonical.com>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

This adds PWM support for Xilinx LogiCORE IP AXI soft timers commonly
found on Xilinx FPGAs. At the moment clock control is very basic: we
just enable the clock during probe and pin the frequency. In the future,
someone could add support for disabling the clock when not in use.

Some common code has been specially demarcated. While currently only
used by the PWM driver, it is anticipated that it may be split off in
the future to be used by the timer driver as well.

This driver was written with reference to Xilinx DS764 for v1.03.a [1].

[1] https://www.xilinx.com/support/documentation/ip_documentation/axi_timer/v1_03_a/axi_timer_ds764.pdfSigned-off-by: Sean Anderson <sean.anderson@seco.com>
Acked-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

This adds a binding for the Xilinx LogiCORE IP AXI Timer. This device is a
"soft" block, so it has some parameters which would not be configurable in
most hardware. This binding is usually automatically generated by Xilinx's
tools, so the names and values of some properties should be kept as they
are, if possible. In addition, this binding is already in the kernel at
arch/microblaze/boot/dts/system.dts, and in user software such as QEMU.

The existing driver uses the clock-frequency property, or alternatively the
/cpus/timebase-frequency property as its frequency input. Because these
properties are deprecated, they have not been included with this schema.
All new bindings should use the clocks/clock-names properties to specify
the parent clock.

Because we need to init timer devices so early in boot, we determine if we
should use the PWM driver or the clocksource/clockevent driver by the
presence/absence, respectively, of #pwm-cells. Because both counters are
used by the PWM, there is no need for a separate property specifying which
counters are to be used for the PWM.
Signed-off-by: Sean Anderson <sean.anderson@seco.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Per-channel data is tracked using struct pwm_device::chip_data and
struct atmel_tcb_pwm_chip::pwms[]. Simplify by using the latter
consistently.
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

This fixes a problem that was supposed to be addressed by commit
6eefb79d ("pwm: sun4i: Remove erroneous else branch") - backlight
could not be switched off on some Allwinner A20.  The commit was
correct, but was not a reliable fix for the problem, which was timing
related.

The real problem for the backlight switching problem was that sleeping
for a full period did not work, because delay_us is always zero.

It is zero because the period (plus 1 microsecond) is rounded down to
the next "jiffies", but the period is less than one jiffy.

On my Cubieboard 2, the period is 5ms, and 1 jiffy (at the default
HZ=100) is 10ms, so nsecs_to_jiffies(10ms+1us)=0.

The roundtrip from nanoseconds to jiffies and back to microseconds is
an unnecessary loss of precision; always rounding down (via
nsecs_to_jiffies()) then causes the breakage.

This patch eliminates this roundtrip, and directly converts from
nanoseconds to microseconds (for usleep_range()), using
DIV_ROUND_UP_ULL() to force rounding up.  This way, the sleep time is
never zero, and after the sleep, we are guaranteed to be in a
different period, and the device is ready for another control command
for sure.
Signed-off-by: Max Kellermann <max.kellermann@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Basically this code did "jiffies + period - jiffies", and we can
simply eliminate the "jiffies" time stamp here.
Signed-off-by: Max Kellermann <max.kellermann@gmail.com>
Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Its value is calculated in sun4i_pwm_apply() and is used only there.
Signed-off-by: Max Kellermann <max.kellermann@gmail.com>
Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Thierry Reding <thierry.reding@gmail.com>

Pull xen fixlet from Juergen Gross:
 "A single cleanup patch for the Xen balloon driver"

* tag 'for-linus-5.18-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen/balloon: don't use PV mode extra memory for zone device allocations

Pull x86 fixes from Thomas Gleixner:
 "Two x86 fixes related to TSX:

   - Use either MSR_TSX_FORCE_ABORT or MSR_IA32_TSX_CTRL to disable TSX
     to cover all CPUs which allow to disable it.

   - Disable TSX development mode at boot so that a microcode update
     which provides TSX development mode does not suddenly make the
     system vulnerable to TSX Asynchronous Abort"

* tag 'x86-urgent-2022-04-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/tsx: Disable TSX development mode at boot
  x86/tsx: Use MSR_TSX_CTRL to clear CPUID bits

Pull timer fixes from Thomas Gleixner:
 "A small set of fixes for the timers core:

   - Fix the warning condition in __run_timers() which does not take
     into account that a CPU base (especially the deferrable base) never
     has a timer armed on it and therefore the next_expiry value can
     become stale.

   - Replace a WARN_ON() in the NOHZ code with a WARN_ON_ONCE() to
     prevent endless spam in dmesg.

   - Remove the double star from a comment which is not meant to be in
     kernel-doc format"

* tag 'timers-urgent-2022-04-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  tick/sched: Fix non-kernel-doc comment
  tick/nohz: Use WARN_ON_ONCE() to prevent console saturation
  timers: Fix warning condition in __run_timers()

Pull SMP fixes from Thomas Gleixner:
 "Two fixes for the SMP core:

   - Make the warning condition in flush_smp_call_function_queue()
     correct, which checked a just emptied list head for being empty
     instead of validating that there was no pending entry on the
     offlined CPU at all.

   - The @cpu member of struct cpuhp_cpu_state is initialized when the
     CPU hotplug thread for the upcoming CPU is created. That's too late
     because the creation of the thread can fail and then the following
     rollback operates on CPU0. Get rid of the CPU member and hand the
     CPU number to the involved functions directly"

* tag 'smp-urgent-2022-04-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  cpu/hotplug: Remove the 'cpu' member of cpuhp_cpu_state
  smp: Fix offline cpu check in flush_smp_call_function_queue()

Pull irq fix from Thomas Gleixner:
 "A single fix for the interrupt affinity spreading logic to take into
  account that there can be an imbalance between present and possible
  CPUs, which causes already assigned bits to be overwritten"

* tag 'irq-urgent-2022-04-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  genirq/affinity: Consider that CPUs on nodes can be unbalanced

Pull power supply fixes from Sebastian Reichel:

 - Fix a regression with battery data failing to load from DT

* tag 'for-v5.18-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/sre/linux-power-supply:
  power: supply: Reset err after not finding static battery
  power: supply: samsung-sdi-battery: Add missing charge restart voltages

Pull i2c fixes from Wolfram Sang:
 "Regular set of fixes for drivers and the dev-interface"

* 'i2c/for-current' of git://git.kernel.org/pub/scm/linux/kernel/git/wsa/linux:
  i2c: ismt: Fix undefined behavior due to shift overflowing the constant
  i2c: dev: Force case user pointers in compat_i2cdev_ioctl()
  i2c: dev: check return value when calling dev_set_name()
  i2c: qcom-geni: Use dev_err_probe() for GPI DMA error
  i2c: imx: Implement errata ERR007805 or e7805 bus frequency limit
  i2c: pasemi: Wait for write xfers to finish

Pull devicetree fixes from Rob Herring:

 - Fix scalar property schemas with array constraints

 - Fix 'enum' lists with duplicate entries

 - Fix incomplete if/then/else schemas

 - Add Renesas RZ/V2L SoC support to Mali Bifrost binding

 - Maintainers update for Marvell irqchip

* tag 'devicetree-fixes-for-5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux:
  dt-bindings: display: panel-timing: Define a single type for properties
  dt-bindings: Fix array constraints on scalar properties
  dt-bindings: gpu: mali-bifrost: Document RZ/V2L SoC
  dt-bindings: net: snps: remove duplicate name
  dt-bindings: Fix 'enum' lists with duplicate entries
  dt-bindings: irqchip: mrvl,intc: refresh maintainers
  dt-bindings: Fix incomplete if/then/else schemas
  dt-bindings: power: renesas,apmu: Fix cpus property limits
  dt-bindings: extcon: maxim,max77843: fix ports type

Pull gpio fixes from Bartosz Golaszewski:
 "A single fix for gpio-sim and two patches for GPIO ACPI pulled from
  Andy:

   - fix the set/get_multiple() callbacks in gpio-sim

   - use correct format characters in gpiolib-acpi

   - use an unsigned type for pins in gpiolib-acpi"

* tag 'gpio-fixes-for-v5.18-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/brgl/linux:
  gpio: sim: fix setting and getting multiple lines
  gpiolib: acpi: Convert type for pin to be unsigned
  gpiolib: acpi: use correct format characters