On Mon, 11 Jan 2021, Thierry Reding wrote: > On Sat, Jan 09, 2021 at 07:02:17PM +0100, Jonathan Neuschäfer wrote: > > 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@xxxxxxx> > > --- > > v7: > > - no changes > > > > v6: > > - https://lore.kernel.org/lkml/20201208011000.3060239-5-j.neuschaefer@xxxxxxx/ > > - Move period / duty cycle setting code to a function > > - Rename pwmchip_to_priv to ntxec_pwm_from_chip > > - Set period and duty cycle only before enabling the output > > - Mention that duty=0, enable=1 is assumed not to happen > > - Interleave writes to the period and duty cycle registers, to minimize the > > window of time that an inconsistent state is configured > > > > v5: > > - https://lore.kernel.org/lkml/20201201011513.1627028-5-j.neuschaefer@xxxxxxx/ > > - Avoid truncation of period and duty cycle to 32 bits > > - Make ntxec_pwm_ops const > > - Use regmap_multi_reg_write > > - Add comment about get_state to ntxec_pwm_ops > > - Add comments about non-atomicity of (period, duty cycle) update > > > > v4: > > - https://lore.kernel.org/lkml/20201122222739.1455132-5-j.neuschaefer@xxxxxxx/ > > - Document hardware/driver limitations > > - Only accept normal polarity > > - Fix a typo ("zone" -> "zero") > > - change MAX_PERIOD_NS to 0xffff * 125 > > - Clamp period to the maximum rather than returning an error > > - Rename private struct pointer to priv > > - Rearrage control flow in _probe to save a few lines and a temporary variable > > - Add missing MODULE_ALIAS line > > - Spell out ODM > > > > v3: > > - https://lore.kernel.org/lkml/20200924192455.2484005-5-j.neuschaefer@xxxxxxx/ > > - Relicense as GPLv2 or later > > - Add email address to copyright line > > - Remove OF compatible string and don't include linux/of_device.h > > - Fix bogus ?: in return line > > - Don't use a comma after sentinels > > - Avoid ret |= ... pattern > > - Move 8-bit register conversion to ntxec.h > > > > v2: > > - https://lore.kernel.org/lkml/20200905133230.1014581-6-j.neuschaefer@xxxxxxx/ > > - Various grammar and style improvements, as suggested by Uwe Kleine-König, > > Lee Jones, and Alexandre Belloni > > - Switch to regmap > > - Prefix registers with NTXEC_REG_ > > - Add help text to the Kconfig option > > - Use the .apply callback instead of the old API > > - Add a #define for the time base (125ns) > > - Don't change device state in .probe; this avoids multiple problems > > - Rework division and overflow check logic to perform divisions in 32 bits > > - Avoid setting duty cycle to zero, to work around a hardware quirk > > --- > > drivers/pwm/Kconfig | 8 ++ > > drivers/pwm/Makefile | 1 + > > drivers/pwm/pwm-ntxec.c | 182 ++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 191 insertions(+) > > create mode 100644 drivers/pwm/pwm-ntxec.c > > Lee, I assume you'll want to pick the whole set up into the MFD tree? If > so: Yes, I'll pick this up once we have all the Acks. The Arm parts usually go in separately. > Acked-by: Thierry Reding <thierry.reding@xxxxxxxxx> Thanks. -- Lee Jones [李琼斯] Senior Technical Lead - Developer Services Linaro.org │ Open source software for Arm SoCs Follow Linaro: Facebook | Twitter | Blog
