Re: [PATCH v3 8/9] media: i2c: ov08d10: add support for reset and power management
From: Matthias Fend
Date: Thu Mar 26 2026 - 13:04:36 EST
Hi Sakari,
Am 26.03.2026 um 14:26 schrieb Sakari Ailus:
Hi Matthias,
A few more minor comments.
On Tue, Mar 24, 2026 at 11:41:42AM +0100, Matthias Fend wrote:
Add support for the required power supplies as well as the control of an
optional sensor reset.
Signed-off-by: Matthias Fend <matthias.fend@xxxxxxxxx>
---
drivers/media/i2c/ov08d10.c | 93 ++++++++++++++++++++++++++++++++++++++++++++-
1 file changed, 92 insertions(+), 1 deletion(-)
diff --git a/drivers/media/i2c/ov08d10.c b/drivers/media/i2c/ov08d10.c
index ce0fa30a86129302b5dda0b8796e44054fd77c88..19035991e8bb164d4fca5d87ee4551191974e8bb 100644
--- a/drivers/media/i2c/ov08d10.c
+++ b/drivers/media/i2c/ov08d10.c
@@ -8,6 +8,7 @@
#include <linux/module.h>
#include <linux/pm_runtime.h>
#include <linux/regulator/consumer.h>
+#include <linux/reset.h>
#include <media/v4l2-ctrls.h>
#include <media/v4l2-device.h>
#include <media/v4l2-fwnode.h>
@@ -513,9 +514,17 @@ static const char * const ov08d10_test_pattern_menu[] = {
"Standard Color Bar",
};
+static const char *const ov08d10_supply_names[] = {
+ "dovdd", /* Digital I/O power */
+ "avdd", /* Analog power */
+ "dvdd", /* Digital core power */
+};
+
struct ov08d10 {
struct device *dev;
struct clk *clk;
+ struct reset_control *reset;
+ struct regulator_bulk_data supplies[ARRAY_SIZE(ov08d10_supply_names)];
struct v4l2_subdev sd;
struct media_pad pad;
@@ -1265,6 +1274,56 @@ static const struct v4l2_subdev_internal_ops ov08d10_internal_ops = {
.open = ov08d10_open,
};
+static int ov08d10_power_off(struct device *dev)
+{
+ struct v4l2_subdev *sd = dev_get_drvdata(dev);
+ struct ov08d10 *ov08d10 = to_ov08d10(sd);
+
+ reset_control_assert(ov08d10->reset);
+
+ regulator_bulk_disable(ARRAY_SIZE(ov08d10->supplies),
+ ov08d10->supplies);
+
+ clk_disable_unprepare(ov08d10->clk);
+
+ return 0;
+}
+
+static int ov08d10_power_on(struct device *dev)
+{
+ struct v4l2_subdev *sd = dev_get_drvdata(dev);
+ struct ov08d10 *ov08d10 = to_ov08d10(sd);
+ int ret;
+
+ ret = regulator_bulk_enable(ARRAY_SIZE(ov08d10->supplies),
+ ov08d10->supplies);
+ if (ret < 0) {
+ dev_err(dev, "failed to enable regulators: %d\n", ret);
+ return ret;
+ }
+
+ ret = clk_prepare_enable(ov08d10->clk);
+ if (ret < 0) {
+ regulator_bulk_disable(ARRAY_SIZE(ov08d10->supplies),
+ ov08d10->supplies);
+
+ dev_err(dev, "failed to enable imaging clock: %d\n", ret);
+ return ret;
+ }
+
+ if (ov08d10->reset) {
+ /* Delay from DVDD stable to sensor XSHUTDN pull up: 5ms */
+ fsleep(5 * USEC_PER_MSEC);
+
+ reset_control_deassert(ov08d10->reset);
+
+ /* Delay from XSHUTDN pull up to SCCB start: 8ms */
+ fsleep(8 * USEC_PER_MSEC);
Don't you need the fsleep()'s (or at least the latter one) even if you have
no reset GPIO?
Good point. I couldn't find any explicit information in the datasheet about operating without a hardware reset.
While I didn't encounter any problems during my tests without a reset, that's probably just coincidence, and I think it's a good idea to wait for the delay you suggested in any case.
+ }
+
+ return 0;
+}
+
static int ov08d10_identify_module(struct ov08d10 *ov08d10)
{
struct i2c_client *client = v4l2_get_subdevdata(&ov08d10->sd);
@@ -1371,6 +1430,10 @@ static void ov08d10_remove(struct i2c_client *client)
media_entity_cleanup(&sd->entity);
v4l2_ctrl_handler_free(sd->ctrl_handler);
pm_runtime_disable(ov08d10->dev);
+ if (!pm_runtime_status_suspended(ov08d10->dev)) {
+ ov08d10_power_off(ov08d10->dev);
+ pm_runtime_set_suspended(ov08d10->dev);
+ }
mutex_destroy(&ov08d10->mutex);
}
@@ -1378,6 +1441,7 @@ static int ov08d10_probe(struct i2c_client *client)
{
struct ov08d10 *ov08d10;
unsigned long freq;
+ unsigned int i;
int ret;
ov08d10 = devm_kzalloc(&client->dev, sizeof(*ov08d10), GFP_KERNEL);
@@ -1403,12 +1467,32 @@ static int ov08d10_probe(struct i2c_client *client)
return ret;
}
+ ov08d10->reset = devm_reset_control_get_optional_exclusive(ov08d10->dev, NULL);
This is a bit long.
I'll take the set now but please post a fix on top.
I just posted a fixup. I hope it was as you intended.
Thanks
~Matthias
+ if (IS_ERR(ov08d10->reset))
+ return dev_err_probe(ov08d10->dev, PTR_ERR(ov08d10->reset),
+ "failed to get reset\n");
+ reset_control_assert(ov08d10->reset);
+
+ for (i = 0; i < ARRAY_SIZE(ov08d10_supply_names); i++)
+ ov08d10->supplies[i].supply = ov08d10_supply_names[i];
+
+ ret = devm_regulator_bulk_get(ov08d10->dev,
+ ARRAY_SIZE(ov08d10->supplies),
+ ov08d10->supplies);
+ if (ret)
+ return dev_err_probe(ov08d10->dev, ret,
+ "failed to get regulators\n");
+
v4l2_i2c_subdev_init(&ov08d10->sd, client, &ov08d10_subdev_ops);
+ ret = ov08d10_power_on(ov08d10->dev);
+ if (ret)
+ return dev_err_probe(ov08d10->dev, ret, "failed to power on\n");
+
ret = ov08d10_identify_module(ov08d10);
if (ret) {
dev_err(ov08d10->dev, "failed to find sensor: %d\n", ret);
- return ret;
+ goto probe_error_power_off;
}
mutex_init(&ov08d10->mutex);
@@ -1452,9 +1536,15 @@ static int ov08d10_probe(struct i2c_client *client)
v4l2_ctrl_handler_free(ov08d10->sd.ctrl_handler);
mutex_destroy(&ov08d10->mutex);
+probe_error_power_off:
+ ov08d10_power_off(ov08d10->dev);
+
return ret;
}
+static DEFINE_RUNTIME_DEV_PM_OPS(ov08d10_pm_ops,
+ ov08d10_power_off, ov08d10_power_on, NULL);
+
#ifdef CONFIG_ACPI
static const struct acpi_device_id ov08d10_acpi_ids[] = {
{ "OVTI08D1" },
@@ -1473,6 +1563,7 @@ MODULE_DEVICE_TABLE(of, ov08d10_of_match);
static struct i2c_driver ov08d10_i2c_driver = {
.driver = {
.name = "ov08d10",
+ .pm = pm_ptr(&ov08d10_pm_ops),
.acpi_match_table = ACPI_PTR(ov08d10_acpi_ids),
.of_match_table = ov08d10_of_match,
},