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ptp: expose the programmable pins via sysfs 

This patch adds the sysfs hooks needed in order to get and set the
programmable pin settings.

Signed-off-by: Richard Cochran <richardcochran@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
hifive-unleashed-5.1
Richard Cochran 2014-03-20 22:21:54 +01:00 committed by David S. Miller
parent 888a36871e
commit 653104d19a
3 changed files with 138 additions and 0 deletions
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20
Documentation/ABI/testing/sysfs-ptp
View File

@ -54,6 +54,26 @@ Description:
This file contains the number of programmable periodic
output channels offered by the PTP hardware clock.
What: /sys/class/ptp/ptpN/n_pins
Date: March 2014
Contact: Richard Cochran <richardcochran@gmail.com>
Description:
This file contains the number of programmable pins
offered by the PTP hardware clock.
What: /sys/class/ptp/ptpN/pins
Date: March 2014
Contact: Richard Cochran <richardcochran@gmail.com>
Description:
This directory contains one file for each programmable
pin offered by the PTP hardware clock. The file name
is the hardware dependent pin name. Reading from this
file produces two numbers, the assigned function (see
the PTP_PF_ enumeration values in linux/ptp_clock.h)
and the channel number. The function and channel
assignment may be changed by two writing numbers into
the file.
What: /sys/class/ptp/ptpN/pps_avaiable
Date: September 2010
Contact: Richard Cochran <richardcochran@gmail.com>

3
drivers/ptp/ptp_private.h
View File

@ -51,6 +51,9 @@ struct ptp_clock {
struct mutex pincfg_mux; /* protect concurrent info->pin_config access */
wait_queue_head_t tsev_wq;
int defunct; /* tells readers to go away when clock is being removed */
struct device_attribute *pin_dev_attr;
struct attribute **pin_attr;
struct attribute_group pin_attr_group;
};
/*

115
drivers/ptp/ptp_sysfs.c
View File

@ -18,6 +18,7 @@
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
*/
#include <linux/capability.h>
#include <linux/slab.h>
#include "ptp_private.h"
@ -42,6 +43,7 @@ PTP_SHOW_INT(max_adjustment, max_adj);
PTP_SHOW_INT(n_alarms, n_alarm);
PTP_SHOW_INT(n_external_timestamps, n_ext_ts);
PTP_SHOW_INT(n_periodic_outputs, n_per_out);
PTP_SHOW_INT(n_programmable_pins, n_pins);
PTP_SHOW_INT(pps_available, pps);
static struct attribute *ptp_attrs[] = {
@ -50,6 +52,7 @@ static struct attribute *ptp_attrs[] = {
&dev_attr_n_alarms.attr,
&dev_attr_n_external_timestamps.attr,
&dev_attr_n_periodic_outputs.attr,
&dev_attr_n_programmable_pins.attr,
&dev_attr_pps_available.attr,
NULL,
};
@ -175,6 +178,63 @@ out:
return err;
}
static int ptp_pin_name2index(struct ptp_clock *ptp, const char *name)
{
int i;
for (i = 0; i < ptp->info->n_pins; i++) {
if (!strcmp(ptp->info->pin_config[i].name, name))
return i;
}
return -1;
}
static ssize_t ptp_pin_show(struct device *dev, struct device_attribute *attr,
char *page)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
unsigned int func, chan;
int index;
index = ptp_pin_name2index(ptp, attr->attr.name);
if (index < 0)
return -EINVAL;
if (mutex_lock_interruptible(&ptp->pincfg_mux))
return -ERESTARTSYS;
func = ptp->info->pin_config[index].func;
chan = ptp->info->pin_config[index].chan;
mutex_unlock(&ptp->pincfg_mux);
return snprintf(page, PAGE_SIZE, "%u %u\n", func, chan);
}
static ssize_t ptp_pin_store(struct device *dev, struct device_attribute *attr,
const char *buf, size_t count)
{
struct ptp_clock *ptp = dev_get_drvdata(dev);
unsigned int func, chan;
int cnt, err, index;
cnt = sscanf(buf, "%u %u", &func, &chan);
if (cnt != 2)
return -EINVAL;
index = ptp_pin_name2index(ptp, attr->attr.name);
if (index < 0)
return -EINVAL;
if (mutex_lock_interruptible(&ptp->pincfg_mux))
return -ERESTARTSYS;
err = ptp_set_pinfunc(ptp, index, func, chan);
mutex_unlock(&ptp->pincfg_mux);
if (err)
return err;
return count;
}
static DEVICE_ATTR(extts_enable, 0220, NULL, extts_enable_store);
static DEVICE_ATTR(fifo, 0444, extts_fifo_show, NULL);
static DEVICE_ATTR(period, 0220, NULL, period_store);
@ -195,9 +255,56 @@ int ptp_cleanup_sysfs(struct ptp_clock *ptp)
if (info->pps)
device_remove_file(dev, &dev_attr_pps_enable);
if (info->n_pins) {
sysfs_remove_group(&dev->kobj, &ptp->pin_attr_group);
kfree(ptp->pin_attr);
kfree(ptp->pin_dev_attr);
}
return 0;
}
static int ptp_populate_pins(struct ptp_clock *ptp)
{
struct device *dev = ptp->dev;
struct ptp_clock_info *info = ptp->info;
int err = -ENOMEM, i, n_pins = info->n_pins;
ptp->pin_dev_attr = kzalloc(n_pins * sizeof(*ptp->pin_dev_attr),
GFP_KERNEL);
if (!ptp->pin_dev_attr)
goto no_dev_attr;
ptp->pin_attr = kzalloc((1 + n_pins) * sizeof(struct attribute *),
GFP_KERNEL);
if (!ptp->pin_attr)
goto no_pin_attr;
for (i = 0; i < n_pins; i++) {
struct device_attribute *da = &ptp->pin_dev_attr[i];
sysfs_attr_init(&da->attr);
da->attr.name = info->pin_config[i].name;
da->attr.mode = 0644;
da->show = ptp_pin_show;
da->store = ptp_pin_store;
ptp->pin_attr[i] = &da->attr;
}
ptp->pin_attr_group.name = "pins";
ptp->pin_attr_group.attrs = ptp->pin_attr;
err = sysfs_create_group(&dev->kobj, &ptp->pin_attr_group);
if (err)
goto no_group;
return 0;
no_group:
kfree(ptp->pin_attr);
no_pin_attr:
kfree(ptp->pin_dev_attr);
no_dev_attr:
return err;
}
int ptp_populate_sysfs(struct ptp_clock *ptp)
{
struct device *dev = ptp->dev;
@ -222,7 +329,15 @@ int ptp_populate_sysfs(struct ptp_clock *ptp)
if (err)
goto out4;
}
if (info->n_pins) {
err = ptp_populate_pins(ptp);
if (err)
goto out5;
}
return 0;
out5:
if (info->pps)
device_remove_file(dev, &dev_attr_pps_enable);
out4:
if (info->n_per_out)
device_remove_file(dev, &dev_attr_period);