From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sven Van Asbroeck Subject: [PATCH 1/1] pwm: pca9685: fix gpio-only operation. Date: Sun, 9 Apr 2017 12:11:24 -0400 Message-ID: <1491754284-3870-2-git-send-email-svenv@arcx.com> References: <1491754284-3870-1-git-send-email-svenv@arcx.com> Return-path: In-Reply-To: <1491754284-3870-1-git-send-email-svenv@arcx.com> Sender: linux-kernel-owner@vger.kernel.org To: thierry.reding@gmail.com Cc: linux-pwm@vger.kernel.org, linux-kernel@vger.kernel.org, clemens.gruber@pqgruber.com, mika.westerberg@linux.intel.com, andriy.shevchenko@linux.intel.com, Sven Van Asbroeck List-Id: linux-pwm@vger.kernel.org gpio-only driver operation never clears the SLEEP bit, which can cause the gpios to become unusable. Example: 1. user requests first pwm -> driver clears SLEEP bit 2. user frees last pwm -> driver sets SLEEP bit 3. user requests gpio 4. user switches gpio on -> output does not turn on because SLEEP bit is set Prevent this behaviour by keeping the SLEEP bit cleared for the lifetime of the driver instance. Fixes: bccec89f0a35 ("Allow any of the 16 PWMs to be used as a GPIO") Signed-off-by: Sven Van Asbroeck --- drivers/pwm/pwm-pca9685.c | 18 +++--------------- 1 file changed, 3 insertions(+), 15 deletions(-) diff --git a/drivers/pwm/pwm-pca9685.c b/drivers/pwm/pwm-pca9685.c index 0cfb357..4b6adaf 100644 --- a/drivers/pwm/pwm-pca9685.c +++ b/drivers/pwm/pwm-pca9685.c @@ -79,7 +79,6 @@ struct pca9685 { struct pwm_chip chip; struct regmap *regmap; - int active_cnt; int duty_ns; int period_ns; #if IS_ENABLED(CONFIG_GPIOLIB) @@ -407,28 +406,14 @@ static int pca9685_pwm_request(struct pwm_chip *chip, struct pwm_device *pwm) if (pca9685_pwm_is_gpio(pca, pwm)) return -EBUSY; - if (pca->active_cnt++ == 0) - return regmap_update_bits(pca->regmap, PCA9685_MODE1, - MODE1_SLEEP, 0x0); - return 0; } -static void pca9685_pwm_free(struct pwm_chip *chip, struct pwm_device *pwm) -{ - struct pca9685 *pca = to_pca(chip); - - if (--pca->active_cnt == 0) - regmap_update_bits(pca->regmap, PCA9685_MODE1, MODE1_SLEEP, - MODE1_SLEEP); -} - static const struct pwm_ops pca9685_pwm_ops = { .enable = pca9685_pwm_enable, .disable = pca9685_pwm_disable, .config = pca9685_pwm_config, .request = pca9685_pwm_request, - .free = pca9685_pwm_free, .owner = THIS_MODULE, }; @@ -479,6 +464,9 @@ static int pca9685_pwm_probe(struct i2c_client *client, /* clear all "full off" bits */ regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_L, 0); regmap_write(pca->regmap, PCA9685_ALL_LED_OFF_H, 0); + /* clear the "sleep" bit */ + regmap_update_bits(pca->regmap, PCA9685_MODE1, + MODE1_SLEEP, 0x0); pca->chip.ops = &pca9685_pwm_ops; /* add an extra channel for ALL_LED */ -- 1.9.1