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: Acked-by: Thierry Reding <thierry.reding@xxxxxxxxx>
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