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From bf1805e0c8c4fc05e2a13b0a03b510ff4e523418 Mon Sep 17 00:00:00 2001
From: Dave Stevenson <dave.stevenson@raspberrypi.org>
Date: Tue, 29 Jan 2019 15:56:10 +0000
Subject: [PATCH] media:bcm2835-unicam: Power on subdev on
open/release, not streaming
The driver was powering on the source subdevice as part of STREAMON,
and powering it off in STREAMOFF. This isn't so great if there is a
significant amount of setup required for your device.
Copy the approach taken in the Atmel ISC driver where s_power(1) is called
on first file handle open, and s_power(0) is called on the last release.
See https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=232437
Signed-off-by: Dave Stevenson <dave.stevenson@raspberrypi.org>
---
.../media/platform/bcm2835/bcm2835-unicam.c | 68 +++++++++++++++----
1 file changed, 54 insertions(+), 14 deletions(-)
--- a/drivers/media/platform/bcm2835/bcm2835-unicam.c
+++ b/drivers/media/platform/bcm2835/bcm2835-unicam.c
@@ -1237,11 +1237,6 @@ static int unicam_start_streaming(struct
unicam_err(dev, "Failed to enable CSI clock: %d\n", ret);
goto err_pm_put;
}
- ret = v4l2_subdev_call(dev->sensor, core, s_power, 1);
- if (ret < 0 && ret != -ENOIOCTLCMD) {
- unicam_err(dev, "power on failed in subdev\n");
- goto err_clock_unprepare;
- }
dev->streaming = 1;
unicam_start_rx(dev, addr);
@@ -1256,8 +1251,6 @@ static int unicam_start_streaming(struct
err_disable_unicam:
unicam_disable(dev);
- v4l2_subdev_call(dev->sensor, core, s_power, 0);
-err_clock_unprepare:
clk_disable_unprepare(dev->clock);
err_pm_put:
unicam_runtime_put(dev);
@@ -1306,11 +1299,6 @@ static void unicam_stop_streaming(struct
dev->next_frm = NULL;
spin_unlock_irqrestore(&dev->dma_queue_lock, flags);
- if (v4l2_subdev_has_op(dev->sensor, core, s_power)) {
- if (v4l2_subdev_call(dev->sensor, core, s_power, 0) < 0)
- unicam_err(dev, "power off failed in subdev\n");
- }
-
clk_disable_unprepare(dev->clock);
unicam_runtime_put(dev);
}
@@ -1543,11 +1531,63 @@ static const struct vb2_ops unicam_video
.stop_streaming = unicam_stop_streaming,
};
+/*
+ * unicam_open : This function is based on the v4l2_fh_open helper function.
+ * It has been augmented to handle sensor subdevice power management,
+ */
+static int unicam_open(struct file *file)
+{
+ struct unicam_device *dev = video_drvdata(file);
+ int ret;
+
+ mutex_lock(&dev->lock);
+
+ ret = v4l2_fh_open(file);
+ if (ret) {
+ unicam_err(dev, "v4l2_fh_open failed\n");
+ goto unlock;
+ }
+
+ if (!v4l2_fh_is_singular_file(file))
+ goto unlock;
+
+ ret = v4l2_subdev_call(dev->sensor, core, s_power, 1);
+ if (ret < 0 && ret != -ENOIOCTLCMD) {
+ v4l2_fh_release(file);
+ goto unlock;
+ }
+
+unlock:
+ mutex_unlock(&dev->lock);
+ return ret;
+}
+
+static int unicam_release(struct file *file)
+{
+ struct unicam_device *dev = video_drvdata(file);
+ struct v4l2_subdev *sd = dev->sensor;
+ bool fh_singular;
+ int ret;
+
+ mutex_lock(&dev->lock);
+
+ fh_singular = v4l2_fh_is_singular_file(file);
+
+ ret = _vb2_fop_release(file, NULL);
+
+ if (fh_singular)
+ v4l2_subdev_call(sd, core, s_power, 0);
+
+ mutex_unlock(&dev->lock);
+
+ return ret;
+}
+
/* unicam capture driver file operations */
static const struct v4l2_file_operations unicam_fops = {
.owner = THIS_MODULE,
- .open = v4l2_fh_open,
- .release = vb2_fop_release,
+ .open = unicam_open,
+ .release = unicam_release,
.read = vb2_fop_read,
.poll = vb2_fop_poll,
.unlocked_ioctl = video_ioctl2,
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