[PATCH v1 1/1] ocp: Add I2C control support for Adva TimeCard

[PATCH v1 1/1] ocp: Add I2C control support for Adva TimeCard

[Sagi Maimon]

- Load i2c-dev module to expose /dev/i2c-N character devices
- Add sysfs-based I2C bus control for Adva TimeCard model

Signed-off-by: Sagi Maimon <maimon.sagi@gmail.com>
---
 drivers/ptp/ptp_ocp.c | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/drivers/ptp/ptp_ocp.c b/drivers/ptp/ptp_ocp.c
index 35e911f1ad78..1b4ccb4feca5 100644
--- a/drivers/ptp/ptp_ocp.c
+++ b/drivers/ptp/ptp_ocp.c
@@ -4224,6 +4224,34 @@ static const struct ocp_attr_group art_timecard_groups[] = {
 	{ },
 };
 
+static ssize_t
+i2c_bus_ctrl_show(struct device *dev, struct device_attribute *attr, char *buf)
+{
+	struct ptp_ocp *bp = dev_get_drvdata(dev);
+
+	if (!bp->pps_select)
+		return -ENODEV;
+	return sysfs_emit(buf, "0x%08x\n",
+			  ioread32(&bp->pps_select->__pad1));
+}
+
+static ssize_t
+i2c_bus_ctrl_store(struct device *dev, struct device_attribute *attr,
+		   const char *buf, size_t count)
+{
+	struct ptp_ocp *bp = dev_get_drvdata(dev);
+	u32 val;
+
+	if (!bp->pps_select)
+		return -ENODEV;
+	if (kstrtou32(buf, 0, &val))
+		return -EINVAL;
+	iowrite32(val, &bp->pps_select->__pad1);
+	return count;
+}
+
+static DEVICE_ATTR_RW(i2c_bus_ctrl);
+
 static struct attribute *adva_timecard_attrs[] = {
 	&dev_attr_serialnum.attr,
 	&dev_attr_gnss_sync.attr,
@@ -4272,6 +4300,7 @@ static struct attribute *adva_timecard_x1_attrs[] = {
 	&dev_attr_ts_window_adjust.attr,
 	&dev_attr_utc_tai_offset.attr,
 	&dev_attr_tod_correction.attr,
+	&dev_attr_i2c_bus_ctrl.attr,
 	NULL,
 };
 
@@ -5235,6 +5264,7 @@ ptp_ocp_init(void)
 	const char *what;
 	int err;
 
+	request_module("i2c-dev");
 	ptp_ocp_debugfs_init();
 
 	what = "timecard class";
-- 
2.47.0

Re: [PATCH v1 1/1] ocp: Add I2C control support for Adva TimeCard

[Andrew Lunn]

On Thu, Jun 25, 2026 at 04:38:02PM +0300, Sagi Maimon wrote:
> - Load i2c-dev module to expose /dev/i2c-N character devices
> - Add sysfs-based I2C bus control for Adva TimeCard model

A list like this suggests the patch should actually be two patches.
Also, the commit message should answer the question "Why?". I can see
what you have done by reading the patch. But Why have you done it?

> +	request_module("i2c-dev");

linux/drivers$ grep -r i2c-dev | grep request
grep: i2c/i2c-dev.o: binary file matches

No other drive does this. Why is this driver special?

    Andrew

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