[PATCH RFC net-next v1 3/9] ptp: expose the programmable pins via sysfs

From: Richard Cochran
Date: Sat Mar 08 2014 - 14:42:51 EST


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

Signed-off-by: Richard Cochran <richardcochran@xxxxxxxxx>
---
Documentation/ABI/testing/sysfs-ptp | 20 +++++++
drivers/ptp/ptp_private.h | 3 +
drivers/ptp/ptp_sysfs.c | 109 +++++++++++++++++++++++++++++++++++
3 files changed, 132 insertions(+)

diff --git a/Documentation/ABI/testing/sysfs-ptp b/Documentation/ABI/testing/sysfs-ptp
index 05aeedf..44806a6 100644
--- a/Documentation/ABI/testing/sysfs-ptp
+++ b/Documentation/ABI/testing/sysfs-ptp
@@ -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@xxxxxxxxx>
+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@xxxxxxxxx>
+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@xxxxxxxxx>
diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index 253e942..fb7c6b1 100644
--- a/drivers/ptp/ptp_private.h
+++ b/drivers/ptp/ptp_private.h
@@ -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;
};

/*
diff --git a/drivers/ptp/ptp_sysfs.c b/drivers/ptp/ptp_sysfs.c
index 13ec531..4495c4d 100644
--- a/drivers/ptp/ptp_sysfs.c
+++ b/drivers/ptp/ptp_sysfs.c
@@ -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 +178,60 @@ 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;
+
+ err = ptp_setpin(ptp, index, func, chan);
+ 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);
@@ -195,7 +252,54 @@ 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)
@@ -222,6 +326,11 @@ int ptp_populate_sysfs(struct ptp_clock *ptp)
if (err)
goto out4;
}
+ if (info->n_pins) {
+ err = ptp_populate_pins(ptp);
+ if (err)
+ goto out4;
+ }
return 0;
out4:
if (info->n_per_out)
--
1.7.10.4

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