From: Hans de Goede <hdegoede@redhat.com>
To: "Thierry Reding" <thierry.reding@gmail.com>,
"Uwe Kleine-König" <u.kleine-koenig@pengutronix.de>,
"Jani Nikula" <jani.nikula@linux.intel.com>,
"Joonas Lahtinen" <joonas.lahtinen@linux.intel.com>,
"Rodrigo Vivi" <rodrigo.vivi@intel.com>,
"Ville Syrjälä" <ville.syrjala@linux.intel.com>,
"Rafael J . Wysocki" <rjw@rjwysocki.net>,
"Len Brown" <lenb@kernel.org>
Cc: Hans de Goede <hdegoede@redhat.com>,
linux-pwm@vger.kernel.org,
intel-gfx <intel-gfx@lists.freedesktop.org>,
dri-devel@lists.freedesktop.org,
Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
Mika Westerberg <mika.westerberg@linux.intel.com>,
linux-acpi@vger.kernel.org
Subject: [PATCH v4 06/16] pwm: lpss: Correct get_state result for base_unit == 0
Date: Wed, 8 Jul 2020 23:14:22 +0200 [thread overview]
Message-ID: <20200708211432.28612-7-hdegoede@redhat.com> (raw)
In-Reply-To: <20200708211432.28612-1-hdegoede@redhat.com>
The datasheet specifies that programming the base_unit part of the
ctrl register to 0 results in a contineous low signal.
Adjust the get_state method to reflect this by setting pwm_state.period
to 1 and duty_cycle to 0.
Suggested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
Changes in v4:
- This is a new patch in v4 of this patchset
---
drivers/pwm/pwm-lpss.c | 16 +++++++++-------
1 file changed, 9 insertions(+), 7 deletions(-)
diff --git a/drivers/pwm/pwm-lpss.c b/drivers/pwm/pwm-lpss.c
index 4f3d60ce9929..4d4de45cf99b 100644
--- a/drivers/pwm/pwm-lpss.c
+++ b/drivers/pwm/pwm-lpss.c
@@ -192,14 +192,16 @@ static void pwm_lpss_get_state(struct pwm_chip *chip, struct pwm_device *pwm,
freq = base_unit * lpwm->info->clk_rate;
do_div(freq, base_unit_range);
- if (freq == 0)
- state->period = NSEC_PER_SEC;
- else
+ if (freq == 0) {
+ /* In this case the PWM outputs a continous low signal */
+ state->period = 1;
+ state->duty_cycle = 0;
+ } else {
state->period = NSEC_PER_SEC / (unsigned long)freq;
-
- on_time_div *= state->period;
- do_div(on_time_div, 255);
- state->duty_cycle = on_time_div;
+ on_time_div *= state->period;
+ do_div(on_time_div, 255);
+ state->duty_cycle = on_time_div;
+ }
state->polarity = PWM_POLARITY_NORMAL;
state->enabled = !!(ctrl & PWM_ENABLE);
--
2.26.2
next prev parent reply other threads:[~2020-07-08 21:15 UTC|newest]
Thread overview: 35+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-08 21:14 [PATCH v4 00/15] acpi/pwm/i915: Convert pwm-crc and i915 driver's PWM code to use the atomic PWM API Hans de Goede
2020-07-08 21:14 ` [PATCH v4 01/16] ACPI / LPSS: Resume Cherry Trail PWM controller in no-irq phase Hans de Goede
2020-07-08 21:14 ` [PATCH v4 02/16] ACPI / LPSS: Save Cherry Trail PWM ctx registers only once (at activation) Hans de Goede
2020-07-08 21:14 ` [PATCH v4 03/16] pwm: lpss: Fix off by one error in base_unit math in pwm_lpss_prepare() Hans de Goede
2020-07-08 21:14 ` [PATCH v4 04/16] pwm: lpss: Add range limit check for the base_unit register value Hans de Goede
2020-07-09 12:53 ` Andy Shevchenko
2020-07-09 13:23 ` Hans de Goede
2020-07-09 14:21 ` Andy Shevchenko
2020-07-09 14:33 ` Hans de Goede
2020-07-09 14:51 ` Andy Shevchenko
2020-07-08 21:14 ` [PATCH v4 05/16] pwm: lpss: Use pwm_lpss_apply() when restoring state on resume Hans de Goede
2020-07-09 13:36 ` Andy Shevchenko
2020-07-09 13:48 ` Hans de Goede
2020-07-08 21:14 ` Hans de Goede [this message]
2020-07-09 14:50 ` [PATCH v4 06/16] pwm: lpss: Correct get_state result for base_unit == 0 Andy Shevchenko
2020-07-09 15:47 ` Hans de Goede
2020-07-11 6:11 ` Uwe Kleine-König
2020-07-11 13:58 ` Hans de Goede
2020-07-08 21:14 ` [PATCH v4 07/16] pwm: crc: Fix period / duty_cycle times being off by a factor of 256 Hans de Goede
2020-07-08 21:14 ` [PATCH v4 08/16] pwm: crc: Fix off-by-one error in the clock-divider calculations Hans de Goede
2020-07-08 21:14 ` [PATCH v4 09/16] pwm: crc: Fix period changes not having any effect Hans de Goede
2020-07-08 21:14 ` [PATCH v4 10/16] pwm: crc: Enable/disable PWM output on enable/disable Hans de Goede
2020-07-08 21:14 ` [PATCH v4 11/16] pwm: crc: Implement apply() method to support the new atomic PWM API Hans de Goede
2020-07-08 21:14 ` [PATCH v4 12/16] pwm: crc: Implement get_state() method Hans de Goede
2020-07-08 21:14 ` [PATCH v4 13/16] drm/i915: panel: Add get_vbt_pwm_freq() helper Hans de Goede
2020-07-08 21:14 ` [PATCH v4 14/16] drm/i915: panel: Honor the VBT PWM frequency for devs with an external PWM controller Hans de Goede
2020-07-08 21:14 ` [PATCH v4 15/16] drm/i915: panel: Honor the VBT PWM min setting " Hans de Goede
2020-07-08 21:14 ` [PATCH v4 16/16] drm/i915: panel: Use atomic PWM API " Hans de Goede
2020-07-11 6:32 ` Uwe Kleine-König
2020-07-11 13:51 ` Hans de Goede
2020-07-09 14:14 ` [PATCH v4 00/15] acpi/pwm/i915: Convert pwm-crc and i915 driver's PWM code to use the atomic PWM API Sam Ravnborg
2020-07-09 14:40 ` Hans de Goede
2020-07-09 15:23 ` Sam Ravnborg
2020-07-11 6:19 ` Uwe Kleine-König
2020-07-11 13:46 ` Hans de Goede
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