Messages in this thread Patch in this message | | | From | Lee Jones <> | Subject | [RESEND 02/11] pwm: sysfs: Add PWM Capture support | Date | Wed, 2 Mar 2016 15:32:00 +0000 |
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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 <lee.jones@linaro.org> --- 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 <linux/kdev_t.h> #include <linux/pwm.h> +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
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