From mboxrd@z Thu Jan 1 00:00:00 1970 From: lee.jones@linaro.org (Lee Jones) Date: Wed, 2 Mar 2016 15:32:00 +0000 Subject: [RESEND 02/11] pwm: sysfs: Add PWM Capture support In-Reply-To: <1456932729-9667-1-git-send-email-lee.jones@linaro.org> References: <1456932729-9667-1-git-send-email-lee.jones@linaro.org> Message-ID: <1456932729-9667-3-git-send-email-lee.jones@linaro.org> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org Allow a user to read PWM Capture results from /sysfs. First, the user must tell PWM Capture which channel they wish to read from: $ echo 2 > $PWMCHIP/capture To start a capture and read the result, simply read the file: $ cat $PWMCHIP/capture The output format is left to the device. Signed-off-by: Lee Jones --- drivers/pwm/sysfs.c | 28 ++++++++++++++++++++++++++++ 1 file changed, 28 insertions(+) diff --git a/drivers/pwm/sysfs.c b/drivers/pwm/sysfs.c index 9c90886..3572ef4 100644 --- a/drivers/pwm/sysfs.c +++ b/drivers/pwm/sysfs.c @@ -23,6 +23,8 @@ #include #include +static int capture_channel; + struct pwm_export { struct device child; struct pwm_device *pwm; @@ -167,16 +169,42 @@ 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); + + return pwm_capture(pwm, capture_channel, buf); +} + +static ssize_t capture_store(struct device *child, + struct device_attribute *attr, + const char *buf, size_t size) +{ + int val, ret; + + ret = kstrtoint(buf, 0, &val); + if (ret) + return ret; + + capture_channel = val; + + return size; +} + static DEVICE_ATTR_RW(period); static DEVICE_ATTR_RW(duty_cycle); static DEVICE_ATTR_RW(enable); static DEVICE_ATTR_RW(polarity); +static DEVICE_ATTR_RW(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); -- 1.9.1