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path: root/drivers/pwm/pwm-meson.c
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2024-03-02pwm: meson: generalize 4 inputs clock on meson8 pwm typeJerome Brunet1-42/+11
Meson8 pwm type always has 4 input clocks. Some inputs may be grounded, like in the AO domain of some SoCs. Drop the parent number parameter and make this is constant. This is also done to make the addition of generic meson8 compatible easier. Signed-off-by: Jerome Brunet <jbrunet@baylibre.com> Link: https://lore.kernel.org/r/20240221151154.26452-4-jbrunet@baylibre.com Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-19pwm: meson: Make use of devm_pwmchip_alloc() functionUwe Kleine-König1-10/+9
This prepares the pwm-meson driver to further changes of the pwm core outlined in the commit introducing devm_pwmchip_alloc(). There is no intended semantical change and the driver should behave as before. Link: https://lore.kernel.org/r/6cc57880e910e6ffd8df15bc4a41c42fe9523293.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-19pwm: meson: Make use of pwmchip_parent() accessorUwe Kleine-König1-8/+8
struct pwm_chip::dev is about to change. To not have to touch this driver in the same commit as struct pwm_chip::dev, use the accessor function provided for exactly this purpose. Link: https://lore.kernel.org/r/02d5f32001c4d0817fa79f5831cfd16b7e345f00.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2024-02-19pwm: meson: Change prototype of a few helpers to prepare further changesUwe Kleine-König1-17/+21
This prepares the driver for further changes that will make it harder to determine the pwm_chip from a given meson_pwm. To just not have to do that, rework meson_pwm_calc(), meson_pwm_enable(), meson_pwm_disable() and meson_pwm_init_channels() to take a pwm_chip. Link: https://lore.kernel.org/r/157084e1dd464da0097edba880240868c1c0b27e.1707900770.git.u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
2023-12-20pwm: meson: Simplify using dev_err_probe()Uwe Kleine-König1-21/+14
Using dev_err_probe() emitting an error message mentioning a return value and returning that value can be done in a single statement. Make use of that to simplify the probe part of the driver. This has the additional advantage to emit the symbolic name for the error instead of the integer error value. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-10-13pwm: Manage owner assignment implicitly for driversUwe Kleine-König1-1/+0
Instead of requiring each driver to care for assigning the owner member of struct pwm_ops, handle that implicitly using a macro. Note that the owner member has to be moved to struct pwm_chip, as the ops structure usually lives in read-only memory and so cannot be modified. The upside is that new low level drivers cannot forget the assignment and save one line each. The pwm-crc driver didn't assign .owner, that's not a problem in practice though as the driver cannot be compiled as a module. Acked-by: Andy Shevchenko <andy.shevchenko@gmail.com> # Intel LPSS Reviewed-by: Florian Fainelli <florian.fainelli@broadcom.com> # pwm-{bcm,brcm}*.c Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> # sun4i Acked-by: Andi Shyti <andi.shyti@kernel.org> Acked-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> # pwm-visconti Acked-by: Heiko Stuebner <heiko@sntech.de> # pwm-rockchip Acked-by: Michael Walle <michael@walle.cc> # pwm-sl28cpld Acked-by: Neil Armstrong <neil.armstrong@linaro.org> # pwm-meson Reviewed-by: Linus Walleij <linus.walleij@linaro.org> Link: https://lore.kernel.org/r/20230804142707.412137-2-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-07-24pwm: Explicitly include correct DT includesRob Herring1-1/+0
The DT of_device.h and of_platform.h date back to the separate of_platform_bus_type before it as merged into the regular platform bus. As part of that merge prepping Arm DT support 13 years ago, they "temporarily" include each other. They also include platform_device.h and of.h. As a result, there's a pretty much random mix of those include files used throughout the tree. In order to detangle these headers and replace the implicit includes with struct declarations, users need to explicitly include the correct includes. Signed-off-by: Rob Herring <robh@kernel.org> Reviewed-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-06-23pwm: meson: make full use of common clock frameworkHeiner Kallweit1-68/+90
Newer versions of the PWM block use a core clock with external mux, divider, and gate. These components either don't exist any longer in the PWM block, or they are bypassed. To minimize needed changes for supporting the new version, the internal divider and gate should be handled by CCF too. I didn't see a good way to split the patch, therefore it's somewhat bigger. What it does: - The internal mux is handled by CCF already. Register also internal divider and gate with CCF, so that we have one representation of the input clock: [mux] parent of [divider] parent of [gate] - Now that CCF selects an appropriate mux parent, we don't need the DT-provided default parent any longer. Accordingly we can also omit setting the mux parent directly in the driver. - Instead of manually handling the pre-div divider value, let CCF set the input clock. Targeted input clock frequency is 0xffff * 1/period for best precision. - For the "inverted pwm disabled" scenario target an input clock frequency of ULONG_MAX. This ensures that the remaining low pulses have minimum length. I don't have hw with the old PWM block, therefore I couldn't test this patch. With the not yet included extension for the new PWM block (channel->clk coming directly from get_clk(external_clk)) I didn't notice any problem. My system uses PWM for the CPU voltage regulator and for the SDIO 32kHz clock. Note: The clock gate in the old PWM block is permanently disabled. This seems to indicate that it's not used by the new PWM block. Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-06-23pwm: meson: don't use hdmi/video clock as mux parentHeiner Kallweit1-21/+3
The meson_vclk code from the display driver may change the rate of the video clock. Therefore better don't use it as pwm mux parent. After removing this clock from the parent list pwm_gxbb_data and pwm_g12a_ee_data are the same as pwm_meson8b_data. So we can remove them. Reported-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-06-23pwm: meson: switch to using struct clk_parent_data for mux parentsHeiner Kallweit1-2/+9
We'll use struct clk_parent_data for mux/div/gate initialization in the follow-up patches. As a first step switch the mux from using parent_names to clk_parent_data. Suggested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Tested-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-06-23pwm: meson: remove not needed check in meson_pwm_calcHeiner Kallweit1-5/+0
period >= duty implies that cnt >= duty_cnt. We verified before that cnt <= 0xffff, therefore we can omit the check here. Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-06-23pwm: meson: fix handling of period/duty if greater than UINT_MAXHeiner Kallweit1-7/+7
state->period/duty are of type u64, and if their value is greater than UINT_MAX, then the cast to uint will cause problems. Fix this by changing the type of the respective local variables to u64. Fixes: b79c3670e120 ("pwm: meson: Don't duplicate the polarity internally") Cc: stable@vger.kernel.org Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-06-23pwm: meson: modify and simplify calculation in meson_pwm_get_stateHeiner Kallweit1-12/+2
I don't see a reason why we should treat the case lo < hi differently and return 0 as period and duty_cycle. The current logic was added with c375bcbaabdb ("pwm: meson: Read the full hardware state in meson_pwm_get_state()"), Martin as original author doesn't remember why it was implemented this way back then. So let's handle it as normal use case and also remove the optimization for lo == 0. I think the improved readability is worth it. Fixes: c375bcbaabdb ("pwm: meson: Read the full hardware state in meson_pwm_get_state()") Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Dmitry Rokosov <ddrokosov@sberdevices.ru> Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Cc: stable@vger.kernel.org Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-04-13pwm: meson: Fix g12a ao clk81 nameHeiner Kallweit1-2/+2
Fix the name of the aoclk81 clock. Apparently name aoclk81 as used by the vendor driver was changed when mainlining the g12a clock driver. Fixes: f41efceb46e6 ("pwm: meson: Add clock source configuration for Meson G12A") Cc: stable@vger.kernel.org Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-04-13pwm: meson: Fix axg ao mux parentsHeiner Kallweit1-1/+1
This fix is basically the same as 9bce02ef0dfa ("pwm: meson: Fix the G12A AO clock parents order"). Vendor driver referenced there has xtal as first parent also for axg ao. In addition fix the name of the aoclk81 clock. Apparently name aoclk81 as used by the vendor driver was changed when mainlining the axg clock driver. Fixes: bccaa3f917c9 ("pwm: meson: Add clock source configuration for Meson-AXG") Cc: stable@vger.kernel.org Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2023-03-23pwm: meson: Explicitly set .polarity in .get_state()Uwe Kleine-König1-0/+8
The driver only supports normal polarity. Complete the implementation of .get_state() by setting .polarity accordingly. This fixes a regression that was possible since commit c73a3107624d ("pwm: Handle .get_state() failures") which stopped to zero-initialize the state passed to the .get_state() callback. This was reported at https://forum.odroid.com/viewtopic.php?f=177&t=46360 . While this was an unintended side effect, the real issue is the driver's callback not setting the polarity. There is a complicating fact, that the .apply() callback fakes support for inversed polarity. This is not (and cannot) be matched by .get_state(). As fixing this isn't easy, only point it out in a comment to prevent authors of other drivers from copying that approach. Fixes: c375bcbaabdb ("pwm: meson: Read the full hardware state in meson_pwm_get_state()") Reported-by: Munehisa Kamata <kamatam@amazon.com> Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Link: https://lore.kernel.org/r/20230310191405.2606296-1-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-12-06pwm: Make .get_state() callback return an error codeUwe Kleine-König1-3/+5
.get_state() might fail in some cases. To make it possible that a driver signals such a failure change the prototype of .get_state() to return an error code. This patch was created using coccinelle and the following semantic patch: @p1@ identifier getstatefunc; identifier driver; @@ struct pwm_ops driver = { ..., .get_state = getstatefunc ,... }; @p2@ identifier p1.getstatefunc; identifier chip, pwm, state; @@ -void +int getstatefunc(struct pwm_chip *chip, struct pwm_device *pwm, struct pwm_state *state) { ... - return; + return 0; ... } plus the actual change of the prototype in include/linux/pwm.h (plus some manual fixing of indentions and empty lines). So for now all drivers return success unconditionally. They are adapted in the following patches to make the changes easier reviewable. Reviewed-by: Heiko Stuebner <heiko@sntech.de> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Tzung-Bi Shih <tzungbi@kernel.org> Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org> Reviewed-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Dave Stevenson <dave.stevenson@raspberrypi.com> Acked-by: Douglas Anderson <dianders@chromium.org> Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com> Acked-by: Pavel Machek <pavel@ucw.cz> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://lore.kernel.org/r/20221130152148.2769768-2-u.kleine-koenig@pengutronix.de Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-02-01pwm: meson: Drop always false check from .apply()Uwe Kleine-König1-3/+0
The PWM core only calls the apply callback with a valid state pointer, so don't repeat this check already done in the core. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-02-01pwm: meson: Simplify duplicated per-channel trackingUwe Kleine-König1-5/+6
The driver tracks per-channel data via struct pwm_device::chip_data and struct meson_pwm::channels[]. The latter holds the actual data, the former is only a pointer to the latter. So simplify by using struct meson_pwm::channels[] consistently. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-02-01pwm: meson: Drop useless check for channel data being NULLUwe Kleine-König1-2/+1
In meson_pwm_free() the function pwm_get_chip_data() always returns a non-NULL pointer because it's only called when the request callback succeeded and this callback calls pwm_set_chip_data() in this case. Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2022-02-01pwm: meson: Drop always false check from .request()Uwe Kleine-König1-7/+1
In .request() pwm_get_chip_data() returns NULL always since commit e926b12c611c ("pwm: Clear chip_data in pwm_put()"). (And if it didn't returning 0 would be wrong because then .request() wouldn't reenable the clk which the other driver code depends on.) Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-06-28pwm: meson: Simplify using devm_pwmchip_add()Uwe Kleine-König1-11/+1
Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-05-25pwm: Simplify all drivers with explicit of_pwm_n_cells = 3Uwe Kleine-König1-2/+0
With the previous commit there is no need for the lowlevel driver any more to specify it it uses two or three cells. So simplify accordingly. The only non-trival change affects the pwm-rockchip driver: It used to only support three cells if the hardware supports polarity. Now the default number depends on the device tree which has to match hardware anyhow (and if it doesn't the error is just a bit delayed as a PWM handle with an inverted setting is catched when pwm_apply_state() is called). Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2021-03-22pwm: Always allocate PWM chip base ID dynamicallyUwe Kleine-König1-1/+0
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>
2020-12-17pwm: meson: Convert to devm_platform_ioremap_resource()Yangtao Li1-3/+1
Use devm_platform_ioremap_resource() to simplify code. Signed-off-by: Yangtao Li <tiny.windzz@gmail.com> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-04-03pwm: meson: Remove redundant assignment to variable fin_freqColin Ian King1-1/+1
The variable fin_freq is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Addresses-Coverity: ("Unused value") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2020-03-30pwm: meson: Fix confusing indentationKrzysztof Kozlowski1-1/+1
Fix indentation of return block. Smatch warning: drivers/pwm/pwm-meson.c:139 meson_pwm_request() warn: inconsistent indenting Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org> Acked-by: Neil Armstrong <narmstrong@baylibre.com> Fixes: 211ed630753d ("pwm: Add support for Meson PWM Controller") Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-09-21pwm: Ensure pwm_apply_state() doesn't modify the state argumentUwe Kleine-König1-2/+2
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>
2019-06-26pwm: meson: Add documentation to the driverMartin Blumenstingl1-0/+22
Add links to the datasheet and a short summary how the hardware works. The goal is to make it easier for other developers to understand why the pwm-meson driver is implemented the way it is. Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Co-authored-by: Neil Armstrong <narmstrong@baylibre.com> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: meson: Add support PWM_POLARITY_INVERSED when disablingMartin Blumenstingl1-1/+22
meson_pwm_apply() has to consider the PWM polarity when disabling the output. With enabled=false and polarity=PWM_POLARITY_NORMAL the output needs to be LOW. The driver already supports this. With enabled=false and polarity=PWM_POLARITY_INVERSED the output needs to be HIGH. Implement this in the driver by internally enabling the output with the same settings that we already use for "period == duty". This fixes a PWM API violation which expects that the driver honors the polarity also for enabled=false. Due to the IP block not supporting this natively we only get "an as close as possible" to 100% HIGH signal (in my test setup with input clock of 24MHz and measuring the output with a logic analyzer at 24MHz sampling rate I got a duty cycle of 99.998475% on a Khadas VIM). Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: meson: Don't cache struct pwm_state internallyMartin Blumenstingl1-24/+1
The PWM core already caches the "current struct pwm_state" as the "current state of the hardware registers" inside struct pwm_device. Drop the struct pwm_state from struct meson_pwm_channel in favour of the struct pwm_state in struct pwm_device. While here also drop any checks based on the pwm_state because the PWM core already takes care of this. No functional changes intended. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: meson: Read the full hardware state in meson_pwm_get_state()Martin Blumenstingl1-3/+49
Update the meson_pwm_get_state() implementation to take care of all information in the registers instead of only reading the "enabled" state. The PWM output is only enabled if two conditions are met: 1. the per-channel clock is enabled 2. the PWM output is enabled Calculate the PWM period and duty cycle using the reverse formula which we already have in meson_pwm_calc() and update struct pwm_state with the results. As result of this /sys/kernel/debug/pwm now shows the PWM state set by the bootloader (or firmware) after booting Linux. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: meson: Simplify the calculation of the pre-divider and countMartin Blumenstingl1-15/+10
Replace the loop to calculate the pre-divider and count with two separate div64_u64() calculations. This makes the code easier to read and improves the precision. Three example cases: 1) 32.768kHz LPO clock for the SDIO wifi chip on Khadas VIM clock input: 500MHz (FCLK_DIV4) period: 30518ns duty cycle: 15259ns old algorithm: pre_div=0, cnt=15259 new algorithm: pre_div=0, cnt=15259 (no difference in calculated values) 2) PWM LED on Khadas VIM clock input: 24MHz (XTAL) period: 7812500ns duty cycle: 7812500ns old algorithm: pre_div=2, cnt=62004 new algorithm: pre_div=2, cnt=62500 Using a scope (24MHz sampling rate) shows the actual difference: - old: 7753000ns, off by -59500ns (0.7616%) - new: 7815000ns, off by +2500ns (0.032%) 3) Theoretical case where pre_div is different clock input: 24MHz (XTAL) period: 2730624ns duty cycle: 1365312ns old algorithm: pre_div=1, cnt=32768 new algorithm: pre_div=0, cnt=65534 Using a scope (24MHz sampling rate) shows the actual difference: - old: 2731000ns - new: 2731000ns (my scope is not precise enough to measure the difference if there's any) Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: meson: Move pwm_set_chip_data() to meson_pwm_request()Martin Blumenstingl1-14/+8
All existing PWM drivers (except pwm-meson and two other ones) call pwm_set_chip_data() from their pwm_ops.request() callback. Now that we can access the struct meson_pwm_channel from struct meson_pwm we can do the same. Move the call to pwm_set_chip_data() to meson_pwm_request() and drop the custom meson_pwm_add_channels(). This makes the implementation consistent with other drivers and makes it slightly more obvious thatpwm_get_chip_data() cannot be used from pwm_ops.get_state() (because that's called by the PWM core before pwm_ops.request()). No functional changes intended. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: meson: Add the per-channel register offsets and bits in a structMartin Blumenstingl1-56/+34
Introduce struct meson_pwm_channel_data which contains the per-channel offsets for the PWM register and REG_MISC_AB bits. Replace the existing switch (pwm->hwpwm) statements with an access to the new struct. This simplifies the code and will make it easier to implement pwm_ops.get_state() because the switch-case which all per-channel registers and offsets (as previously implemented in meson_pwm_enable()) doesn't have to be duplicated. No functional changes intended. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: meson: Add the meson_pwm_channel data to struct meson_pwmMartin Blumenstingl1-15/+10
Make struct meson_pwm_channel accessible from struct meson_pwm. PWM core has a limitation: per-channel data can only be set after pwmchip_add() is called. However, pwmchip_add() internally calls pwm_ops.get_state(). If pwm_ops.get_state() needs access to the per-channel data it has to obtain it from struct pwm_chip and struct pwm_device's hwpwm information. Add a struct meson_pwm_channel for each PWM channel to struct meson_pwm so the pwm_ops.get_state() callback can be implemented as it needs access to the clock from struct meson_pwm_channel. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: meson: Pass struct pwm_device to meson_pwm_calc()Martin Blumenstingl1-3/+3
meson_pwm_calc() is the last function that accepts a struct meson_pwm_channel. meson_pwm_enable(), meson_pwm_disable() and meson_pwm_apply() for example are all taking a struct pwm_device as parameter. When they need the struct meson_pwm_channel these functions simply call pwm_get_chip_data() internally. Make meson_pwm_calc() consistent with the other functions in the meson-pwm driver by passing struct pwm_device to it as well. The value of the "id" parameter is actually pwm->hwpwm, but the driver never read the "id" parameter, which is why there's no replacement for it in the new code. No functional changes. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: meson: Don't duplicate the polarity internallyMartin Blumenstingl1-15/+8
Let meson_pwm_calc() use the polarity from struct pwm_state directly. This removes a level of indirection where meson_pwm_apply() first had to set a driver-internal inverter mask which was then only used by meson_pwm_calc(). Instead of adding the polarity as parameter to meson_pwm_calc() switch to struct pwm_state directly to make it easier to see where the parameters are actually coming from. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: meson: Change MISC_CLK_SEL_WIDTH to MISC_CLK_SEL_MASKMartin Blumenstingl1-2/+2
MISC_CLK_SEL_WIDTH is only used in one place where it's converted into a bit-mask. Rename and change the macro to be a bit-mask so that conversion is not needed anymore. No functional changes intended. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: meson: Use GENMASK and FIELD_PREP for the lo and hi valuesMartin Blumenstingl1-2/+6
meson_pwm_calc() ensures that "lo" is always less than 16 bits wide (otherwise it would overflow into the "hi" part of the REG_PWM_{A,B} register). Use GENMASK and FIELD_PREP for the lo and hi values to make it easier to spot how wide these are internally. Additionally this is a preparation step for the .get_state() implementation where the GENMASK() for lo and hi becomes handy because it can be used with FIELD_GET() to extract the values from the register REG_PWM_{A,B} register. No functional changes intended. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: meson: Use devm_clk_get_optional() to get the input clockMartin Blumenstingl1-8/+3
Simplify the code which fetches the input clock for a PWM channel by using devm_clk_get_optional(). This comes with a small functional change: previously all errors except EPROBE_DEFER were ignored. Now all other errors are also treated as errors. If no input clock is present devm_clk_get_optional() will return NULL instead of an error which matches the behavior of the old code. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-26pwm: meson: Unify the parameter list of meson_pwm_{enable, disable}Martin Blumenstingl1-8/+7
This is a preparation for a future cleanup. Pass struct pwm_device instead of passing the individual values required by each function as these can be obtained for each struct pwm_device instance. As a nice side-effect the driver now uses "switch (pwm->hwpwm)" everywhere. Before some functions used "switch (id)" while others used "switch (pwm->hwpwm)". No functional changes. Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-25pwm: meson: Fix the G12A AO clock parents orderNeil Armstrong1-2/+11
The Amlogic G12A and G12B Documentation is wrong, the AO xtal and clk81 clock source order is reversed, and validated when adding DVFS support by using the PWM AO D output to control the CPU supply voltage. The vendor tree also uses the reversed xtal and clk81 order at [1]. [1] https://github.com/hardkernel/linux/blob/odroidn2-4.9.y/drivers/amlogic/pwm/pwm_meson.c#L462 Fixes: f41efceb46e6 ("pwm: meson: Add clock source configuration for Meson G12A") Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Acked-by: Kevin Hilman <khilman@baylibre.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-06-25pwm: meson: Update with SPDX Licence identifierNeil Armstrong1-51/+1
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-05-10Merge tag 'pwm/for-5.2-rc1' of ↵Linus Torvalds1-15/+49
ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm Pull pwm updates from Thierry Reding: "Nothing out of the ordinary this cycle. The bulk of this is a collection of fixes for existing drivers and some cleanups. There's one new driver for i.MX SoCs and addition of support for some new variants to existing drivers" * tag 'pwm/for-5.2-rc1' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/thierry.reding/linux-pwm: pwm: meson: Add clock source configuration for Meson G12A dt-bindings: pwm: Update bindings for the Meson G12A Family pwm: samsung: Don't uses devm_*() functions in ->request() pwm: Clear chip_data in pwm_put() pwm: Add i.MX TPM PWM driver support dt-bindings: pwm: Add i.MX TPM PWM binding pwm: imx27: Use devm_platform_ioremap_resource() to simplify code pwm: meson: Use the spin-lock only to protect register modifications pwm: meson: Don't disable PWM when setting duty repeatedly pwm: meson: Consider 128 a valid pre-divider pwm: sysfs: fix typo "its" -> "it's" pwm: tiehrpwm: Enable compilation for ARCH_K3 dt-bindings: pwm: tiehrpwm: Add TI AM654 SoC specific compatible pwm: tiehrpwm: Update shadow register for disabling PWMs pwm: img: Turn final 'else if' into 'else' in img_pwm_config pwm: Fix deadlock warning when removing PWM device
2019-05-09pwm: meson: Add clock source configuration for Meson G12ANeil Armstrong1-0/+30
For the PWM controller in the Meson G12A SoC, the EE domain and AO domain have different clock sources. This patch tries to describe them in the DT compatible data. The two AO PWM controller has different clock source, but the first AO controller (A & B) can reuse the AXG parents name. Signed-off-by: Neil Armstrong <narmstrong@baylibre.com> Reviewed-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-05-09pwm: meson: Use the spin-lock only to protect register modificationsMartin Blumenstingl1-8/+17
Holding the spin-lock for all of the code in meson_pwm_apply() can result in a "BUG: scheduling while atomic". This can happen because clk_get_rate() (which is called from meson_pwm_calc()) may sleep. Only hold the spin-lock when modifying registers to solve this. The reason why we need a spin-lock in the driver is because the REG_MISC_AB register is shared between the two channels provided by one PWM controller. The only functions where REG_MISC_AB is modified are meson_pwm_enable() and meson_pwm_disable() so the register reads/writes in there need to be protected by the spin-lock. The original code also used the spin-lock to protect the values in struct meson_pwm_channel. This could be necessary if two consumers can use the same PWM channel. However, PWM core doesn't allow this so we don't need to protect the values in struct meson_pwm_channel with a lock. Fixes: 211ed630753d2f ("pwm: Add support for Meson PWM Controller") Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Reviewed-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-05-09pwm: meson: Don't disable PWM when setting duty repeatedlyBichao Zheng1-5/+0
There is an abnormally low about 20ms,when setting duty repeatedly. Because setting the duty will disable PWM and then enable. Delete this operation now. Fixes: 211ed630753d2f ("pwm: Add support for Meson PWM Controller") Signed-off-by: Bichao Zheng <bichao.zheng@amlogic.com> [ Dropped code instead of hiding it behind a comment ] Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-05-09pwm: meson: Consider 128 a valid pre-dividerMartin Blumenstingl1-2/+2
The pre-divider allows configuring longer PWM periods compared to using the input clock directly. The pre-divider is 7 bit wide, meaning it's maximum value is 128 (the register value is off-by-one: 0x7f or 127). Change the loop to also allow for the maximum possible value to be considered valid. Fixes: 211ed630753d2f ("pwm: Add support for Meson PWM Controller") Signed-off-by: Martin Blumenstingl <martin.blumenstingl@googlemail.com> Acked-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de> Reviewed-by: Neil Armstrong <narmstrong@baylibre.com> Signed-off-by: Thierry Reding <thierry.reding@gmail.com>
2019-04-26clk: Remove CLK_IS_BASIC clk flagStephen Boyd1-1/+1
This flag was historically used to indicate that a clk is a "basic" type of clk like a mux, divider, gate, etc. This never turned out to be very useful though because it was hard to cleanly split "basic" clks from other clks in a system. This one flag was a way for type introspection and it just didn't scale. If anything, it was used by the TI clk driver to indicate that a clk_hw wasn't contained in the SoC specific clk structure. We can get rid of this define now that TI is finding those clks a different way. Cc: Tero Kristo <t-kristo@ti.com> Cc: Ralf Baechle <ralf@linux-mips.org> Cc: Paul Burton <paul.burton@mips.com> Cc: James Hogan <jhogan@kernel.org> Cc: <linux-mips@vger.kernel.org> Cc: Thierry Reding <thierry.reding@gmail.com> Cc: Kevin Hilman <khilman@baylibre.com> Cc: <linux-pwm@vger.kernel.org> Cc: <linux-amlogic@lists.infradead.org> Acked-by: Thierry Reding <treding@nvidia.com> Signed-off-by: Stephen Boyd <sboyd@kernel.org>