From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lee Jones Subject: [PATCH v3 10/20] pwm: sysfs: Add PWM Capture support Date: Wed, 8 Jun 2016 10:21:25 +0100 Message-ID: <20160608092135.21184-11-lee.jones@linaro.org> References: <20160608092135.21184-1-lee.jones@linaro.org> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20160608092135.21184-1-lee.jones@linaro.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=m.gmane.org@lists.infradead.org To: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org Cc: linux-pwm@vger.kernel.org, kernel@stlinux.com, devicetree@vger.kernel.org, patrice.chotard@st.com, robh+dt@kernel.org, thierry.reding@gmail.com, Lee Jones , maxime.coquelin@st.com List-Id: devicetree@vger.kernel.org Allow a user to read PWM Capture results from /sysfs. To start a capture and read the result, simply read the file: $ cat $PWMCHIP/capture The output format is ":". Signed-off-by: Lee Jones --- drivers/pwm/sysfs.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c index d985992..901e647 100644 --- a/drivers/pwm/sysfs.c +++ b/drivers/pwm/sysfs.c @@ -208,16 +208,33 @@ static ssize_t polarity_store(struct device *child, return ret ? : size; } +static ssize_t capture_show(struct device *child, + struct device_attribute *attr, + char *buf) +{ + struct pwm_device *pwm = child_to_pwm_device(child); + struct pwm_capture result; + int ret; + + ret = pwm_capture(pwm, &result, jiffies_to_msecs(HZ)); + if (ret) + return ret; + + return sprintf(buf, "%llu %llu\n", result.period, result.duty_cycle); +} + static DEVICE_ATTR_RW(period); static DEVICE_ATTR_RW(duty_cycle); static DEVICE_ATTR_RW(enable); static DEVICE_ATTR_RW(polarity); +static DEVICE_ATTR_RO(capture); static struct attribute *pwm_attrs[] = { &dev_attr_period.attr, &dev_attr_duty_cycle.attr, &dev_attr_enable.attr, &dev_attr_polarity.attr, + &dev_attr_capture.attr, NULL }; ATTRIBUTE_GROUPS(pwm); -- 2.8.3