From: Clemens Gruber <clemens.gruber@pqgruber.com>
To: linux-pwm@vger.kernel.org
Cc: Thierry Reding <thierry.reding@gmail.com>,
u.kleine-koenig@pengutronix.de,
Sven Van Asbroeck <TheSven73@gmail.com>,
Lee Jones <lee.jones@linaro.org>,
linux-kernel@vger.kernel.org,
Mika Westerberg <mika.westerberg@linux.intel.com>,
David Jander <david@protonic.nl>,
Clemens Gruber <clemens.gruber@pqgruber.com>
Subject: [PATCH v5 4/7] pwm: pca9685: Reset registers to POR state in probe
Date: Tue, 15 Dec 2020 22:22:25 +0100 [thread overview]
Message-ID: <20201215212228.185517-4-clemens.gruber@pqgruber.com> (raw)
In-Reply-To: <20201215212228.185517-1-clemens.gruber@pqgruber.com>
Reset the prescale and ON/OFF registers to their POR default state in
the probe function. Otherwise, the PWMs could still be active after a
watchdog reset and reboot, etc.
Signed-off-by: Clemens Gruber <clemens.gruber@pqgruber.com>
---
drivers/pwm/pwm-pca9685.c | 9 +++++++--
1 file changed, 7 insertions(+), 2 deletions(-)
diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c
index 7b14447f3c05..38aadaf50996 100644
--- a/drivers/pwm/pwm-pca9685.c
+++ b/drivers/pwm/pwm-pca9685.c
@@ -47,6 +47,7 @@
#define PCA9685_ALL_LED_OFF_H 0xFD
#define PCA9685_PRESCALE 0xFE
+#define PCA9685_PRESCALE_DEF 0x1E /* => default frequency of ~200 Hz */
#define PCA9685_PRESCALE_MIN 0x03 /* => max. frequency of 1526 Hz */
#define PCA9685_PRESCALE_MAX 0xFF /* => min. frequency of 24 Hz */
@@ -446,9 +447,11 @@ static int pca9685_pwm_probe(struct i2c_client *client,
reg &= ~(MODE1_ALLCALL | MODE1_SUB1 | MODE1_SUB2 | MODE1_SUB3);
regmap_write(pca->regmap, PCA9685_MODE1, reg);
- /* Clear all "full off" bits */
+ /* Reset ON/OFF registers to HW defaults (only full OFF bit is set) */
+ regmap_write(pca->regmap, PCA9685_ALL_LED_ON_L, 0);
+ regmap_write(pca->regmap, PCA9685_ALL_LED_ON_H, 0);
regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0);
- regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0);
+ regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, LED_FULL);
pca->chip.ops = &pca9685_pwm_ops;
/* Add an extra channel for ALL_LED */
@@ -470,8 +473,10 @@ static int pca9685_pwm_probe(struct i2c_client *client,
/*
* The chip comes out of power-up in the sleep state,
* but force it to sleep in case it was woken up before
+ * and set the default prescale value
*/
pca9685_set_sleep_mode(pca, true);
+ regmap_write(pca->regmap, PCA9685_PRESCALE, PCA9685_PRESCALE_DEF);
pm_runtime_set_suspended(&client->dev);
pm_runtime_enable(&client->dev);
--
2.29.2
next prev parent reply other threads:[~2020-12-15 21:29 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-15 21:22 [PATCH v5 1/7] pwm: pca9685: Switch to atomic API Clemens Gruber
2020-12-15 21:22 ` [PATCH v5 2/7] pwm: pca9685: Support hardware readout Clemens Gruber
2020-12-15 21:22 ` [PATCH v5 3/7] pwm: pca9685: Improve runtime PM behavior Clemens Gruber
2020-12-15 21:22 ` Clemens Gruber [this message]
2020-12-17 4:02 ` [PATCH v5 4/7] pwm: pca9685: Reset registers to POR state in probe Sven Van Asbroeck
2020-12-17 17:45 ` Clemens Gruber
2021-03-01 21:46 ` Uwe Kleine-König
2021-03-04 13:16 ` Clemens Gruber
2020-12-15 21:22 ` [PATCH v5 5/7] pwm: pca9685: Support staggered output ON times Clemens Gruber
2020-12-17 4:02 ` Sven Van Asbroeck
2020-12-17 17:50 ` Clemens Gruber
2020-12-15 21:22 ` [PATCH v5 6/7] dt-bindings: pwm: pca9685: Add nxp,staggered-outputs property Clemens Gruber
2020-12-15 21:22 ` [PATCH v5 7/7] pwm: pca9685: Restrict period change for prescaler users Clemens Gruber
2020-12-17 4:03 ` Sven Van Asbroeck
2020-12-17 18:07 ` Clemens Gruber
2020-12-17 18:17 ` Sven Van Asbroeck
2020-12-17 3:58 ` [PATCH v5 1/7] pwm: pca9685: Switch to atomic API Sven Van Asbroeck
2020-12-17 16:48 ` Clemens Gruber
2020-12-17 17:10 ` Sven Van Asbroeck
2021-03-01 21:41 ` Uwe Kleine-König
2021-03-04 13:10 ` Clemens Gruber
2021-03-22 7:58 ` Thierry Reding
2021-03-27 15:54 ` Clemens Gruber
2021-03-01 21:44 ` Uwe Kleine-König
2021-03-04 13:12 ` Clemens Gruber
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20201215212228.185517-4-clemens.gruber@pqgruber.com \
--to=clemens.gruber@pqgruber.com \
--cc=TheSven73@gmail.com \
--cc=david@protonic.nl \
--cc=lee.jones@linaro.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-pwm@vger.kernel.org \
--cc=mika.westerberg@linux.intel.com \
--cc=thierry.reding@gmail.com \
--cc=u.kleine-koenig@pengutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).