Because period and duty cycle are defined in the PWM framework structs as ints with units of nanoseconds, the maximum time duration that can be set is limited to ~2.147 seconds. Consequently, applications desiring to set greater time periods via the PWM framework are not be able to do so - like, for instance, causing an LED to blink at an interval of 5 seconds.
Redefining the period and duty cycle struct members in the core PWM framework structs as u64 values will enable larger time durations to be set and solve this problem. Such a change to the framework mandates that drivers using these struct members (and corresponding helper functions) also be modified correctly in order to prevent compilation errors.
This patch series introduces the changes to all the drivers first, followed by the framework change at the very end so that when the latter is applied, all the drivers are in good shape and there are no compilation errors.
Changes from v8: - Gathered all received "Acked-by: " and "Reviewed-by: " tags - Dropped patch to clk-pwm.c for reasons mentiond in [2] - Expanded audience of unreviewed patches
Changes from v7: - Changed commit messages of all patches to be brief and to the point. - Added explanation of change in cover letter. - Dropped change to pwm-sti.c as upon review it was unnecessary as struct pwm_capture is not being modified in the PWM core.
Changes from v6: - Split out the driver changes out into separate patches, one patch per file for ease of reviewing.
Changes from v5: - Dropped the conversion of struct pwm_capture to u64 for reasons mentioned in https://www.spinics.net/lists/linux-pwm/msg11541.html
Changes from v4: - Split the patch into two: one for changes to the drivers, and the actual switch to u64 for ease of reverting should the need arise. - Re-examined the patch and made the following corrections: * intel_panel.c: DIV64_U64_ROUND_UP -> DIV_ROUND_UP_ULL (as only the numerator would be 64-bit in this case). * pwm-sti.c: do_div -> div_u64 (do_div is optimized only for x86 architectures, and div_u64's comment block suggests to use this as much as possible).
Changes from v3: - Rebased to current tip of for-next.
Changes from v2: - Fixed %u -> %llu in a dev_dbg in pwm-stm32-lp.c, thanks to kbuild test robot - Added a couple of fixes to pwm-imx-tpm.c and pwm-sifive.c
Changes from v1: - Fixed compilation errors seen when compiling for different archs.
v1: - Reworked the change pushed upstream earlier [1] so as to not add an extension to an obsolete API. With this change, pwm_ops->apply() can be used to set pwm_state parameters as usual.
[1] https://lore.kernel.org/lkml/20190916140048.GB7488@ulmo/ [2] https://lore.kernel.org/lkml/20200312190859.GA19605@codeaurora.org/
Guru Das Srinagesh (11): drm/i915: Use 64-bit division macro hwmon: pwm-fan: Use 64-bit division macro ir-rx51: Use 64-bit division macro pwm: clps711x: Use 64-bit division macro pwm: pwm-imx-tpm: Use 64-bit division macro pwm: imx27: Use 64-bit division macro and function pwm: sifive: Use 64-bit division macro pwm: stm32-lp: Use %llu format specifier for period pwm: sun4i: Use 64-bit division function backlight: pwm_bl: Use 64-bit division function pwm: core: Convert period and duty cycle to u64
drivers/gpu/drm/i915/display/intel_panel.c | 2 +- drivers/hwmon/pwm-fan.c | 2 +- drivers/media/rc/ir-rx51.c | 3 ++- drivers/pwm/core.c | 4 ++-- drivers/pwm/pwm-clps711x.c | 2 +- drivers/pwm/pwm-imx-tpm.c | 2 +- drivers/pwm/pwm-imx27.c | 5 ++--- drivers/pwm/pwm-sifive.c | 2 +- drivers/pwm/pwm-stm32-lp.c | 2 +- drivers/pwm/pwm-sun4i.c | 2 +- drivers/pwm/sysfs.c | 8 ++++---- drivers/video/backlight/pwm_bl.c | 3 ++- include/linux/pwm.h | 12 ++++++------ 13 files changed, 25 insertions(+), 24 deletions(-)
Cc: Lee Jones lee.jones@linaro.org Cc: Daniel Thompson daniel.thompson@linaro.org Cc: Jingoo Han jingoohan1@gmail.com Cc: Bartlomiej Zolnierkiewicz b.zolnierkie@samsung.com Cc: linux-fbdev@vger.kernel.org Cc: Maxime Ripard mripard@kernel.org Cc: Chen-Yu Tsai wens@csie.org Cc: Philipp Zabel p.zabel@pengutronix.de Cc: Fabrice Gasnier fabrice.gasnier@st.com Cc: Maxime Coquelin mcoquelin.stm32@gmail.com Cc: Alexandre Torgue alexandre.torgue@st.com Cc: Palmer Dabbelt palmer@dabbelt.com Cc: Paul Walmsley paul.walmsley@sifive.com Cc: linux-riscv@lists.infradead.org Cc: Yash Shah yash.shah@sifive.com Cc: Atish Patra atish.patra@wdc.com Cc: Shawn Guo shawnguo@kernel.org Cc: Sascha Hauer s.hauer@pengutronix.de Cc: Pengutronix Kernel Team kernel@pengutronix.de Cc: Fabio Estevam festevam@gmail.com Cc: NXP Linux Team linux-imx@nxp.com Cc: Sascha Hauer s.hauer@pengutronix.de Cc: Pengutronix Kernel Team kernel@pengutronix.de Cc: Fabio Estevam festevam@gmail.com Cc: NXP Linux Team linux-imx@nxp.com Cc: Alexander Shiyan shc_work@mail.ru Cc: Mauro Carvalho Chehab mchehab@kernel.org Cc: Richard Fontana rfontana@redhat.com Cc: Thomas Gleixner tglx@linutronix.de Cc: Kate Stewart kstewart@linuxfoundation.org Cc: Allison Randal allison@lohutok.net Cc: linux-media@vger.kernel.org Cc: Kamil Debski kamil@wypas.org Cc: Bartlomiej Zolnierkiewicz b.zolnierkie@samsung.com Cc: Jean Delvare jdelvare@suse.com Cc: Guenter Roeck linux@roeck-us.net Cc: Liam Girdwood lgirdwood@gmail.com Cc: Mark Brown broonie@kernel.org Cc: linux-hwmon@vger.kernel.org Cc: Jani Nikula jani.nikula@linux.intel.com Cc: Joonas Lahtinen joonas.lahtinen@linux.intel.com Cc: David Airlie airlied@linux.ie Cc: Daniel Vetter daniel@ffwll.ch Cc: Chris Wilson chris@chris-wilson.co.uk Cc: "Ville Syrjälä" ville.syrjala@linux.intel.com Cc: intel-gfx@lists.freedesktop.org Cc: dri-devel@lists.freedesktop.org Cc: Michael Turquette mturquette@baylibre.com Cc: Stephen Boyd sboyd@kernel.org Cc: linux-clk@vger.kernel.org Cc: Rodrigo Vivi rodrigo.vivi@intel.com Cc: Maarten Lankhorst maarten.lankhorst@linux.intel.com Cc: Arnd Bergmann arnd@arndb.de Cc: Mukesh Ojha mojha@codeaurora.org Cc: Dan Carpenter dan.carpenter@oracle.com Cc: Anson Huang Anson.Huang@nxp.com Cc: Gerald Baeza gerald.baeza@st.com Cc: Benjamin Gaignard benjamin.gaignard@linaro.org Cc: Axel Lin axel.lin@ingics.com Cc: Ding Xiang dingxiang@cmss.chinamobile.com Cc: Wesley W. Terpstra wesley@sifive.com