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>

diff --git a/Documentation/ABI/testing/sysfs-ptp b/Documentation/ABI/testing/sysfs-ptp
index 05aeedf..44806a6 100644 (file)
--- 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@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>

diff --git a/drivers/ptp/ptp_private.h b/drivers/ptp/ptp_private.h
index b114a84..9c5d414 100644 (file)
--- 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..302e626 100644 (file)
--- 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 +178,63 @@ 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);