* v4l: Add camera voice coil lens control class, current control
@ 2017-02-14 12:03 Sakari Ailus
2017-02-14 12:03 ` [PATCH v2 1/2] " Sakari Ailus
2017-02-14 12:03 ` [PATCH v2 2/2] ad5820: Use VOICE_COIL_CURRENT control Sakari Ailus
0 siblings, 2 replies; 3+ messages in thread
From: Sakari Ailus @ 2017-02-14 12:03 UTC (permalink / raw)
To: linux-media; +Cc: pavel
Hi folks,
I wanted to refresh my voice coil lens patchset before we have more voice
coil lens controller drivers. The VOCUS_ABSOLUTE control really is not a
best control ID to control a voice coil driver's current.
There may be additional controls in the class: the hardware I'm familiar
with provides other controls (PWM vs. linear mode, resonance frequency and
ringing compensation formula to name a few) but I'm not fully certain
they're something that even should be told to the user --- let alone
giving the user write access to them.
My expectation is still that there will be more controls in the class. The
PWM / linear mode might be one candidate: PWM saves power but it may cause
other issues. These other issues might be something to ignore, depending
on the use case. That will be anyway left for the future.
--
Kind regards,
Sakari
^ permalink raw reply [flat|nested] 3+ messages in thread
* [PATCH v2 1/2] v4l: Add camera voice coil lens control class, current control
2017-02-14 12:03 v4l: Add camera voice coil lens control class, current control Sakari Ailus
@ 2017-02-14 12:03 ` Sakari Ailus
2017-02-14 12:03 ` [PATCH v2 2/2] ad5820: Use VOICE_COIL_CURRENT control Sakari Ailus
1 sibling, 0 replies; 3+ messages in thread
From: Sakari Ailus @ 2017-02-14 12:03 UTC (permalink / raw)
To: linux-media; +Cc: pavel
Add a V4L2 control class for voice coil lens driver devices. These are
simple devices that are used to move a camera lens from its resting
position.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
Documentation/media/uapi/v4l/extended-controls.rst | 28 ++++++++++++++++++++++
drivers/media/i2c/ad5820.c | 3 +++
include/uapi/linux/v4l2-controls.h | 9 ++++++-
3 files changed, 39 insertions(+), 1 deletion(-)
diff --git a/Documentation/media/uapi/v4l/extended-controls.rst b/Documentation/media/uapi/v4l/extended-controls.rst
index abb1057..a75451a 100644
--- a/Documentation/media/uapi/v4l/extended-controls.rst
+++ b/Documentation/media/uapi/v4l/extended-controls.rst
@@ -3022,6 +3022,34 @@ Image Process Control IDs
driver specific and are documented in :ref:`v4l-drivers`.
+.. _voice-coil-lens-controls:
+
+Voice Coil Lens Control Reference
+=================================
+
+The Voice Coil class controls are used to control voice coil lens
+devices. These are very simple devices that consist of a voice coil, a
+spring and a lens. The current applied on the voice coil is used to
+move the lens away from the resting position which typically is (close
+to) infinity. The higher the current applied, the closer the lens is
+typically focused.
+
+.. _voice-coil-lens-control-is:
+
+Voice Coil Lens Control IDs
+---------------------------
+
+``V4L2_CID_VOICE_COIL_CLASS (class)``
+ The VOICE_COIL class descriptor.
+
+``V4L2_CID_VOICE_COIL_CURRENT (integer)``
+ Current applied on a voice coil. The more current is applied, the
+ more is the position of the lens moved from its resting position.
+ Do note that there may be a ringing effect; the lens will
+ oscillate after changing the current applied unless the device
+ implements ringing compensation.
+
+
.. _dv-controls:
Digital Video Control Reference
diff --git a/drivers/media/i2c/ad5820.c b/drivers/media/i2c/ad5820.c
index a9026a91..7167b26 100644
--- a/drivers/media/i2c/ad5820.c
+++ b/drivers/media/i2c/ad5820.c
@@ -162,6 +162,7 @@ static int ad5820_set_ctrl(struct v4l2_ctrl *ctrl)
switch (ctrl->id) {
case V4L2_CID_FOCUS_ABSOLUTE:
+ case V4L2_CID_VOICE_COIL_CURRENT:
coil->focus_absolute = ctrl->val;
return ad5820_update_hw(coil);
}
@@ -192,6 +193,8 @@ static int ad5820_init_controls(struct ad5820_device *coil)
*/
v4l2_ctrl_new_std(&coil->ctrls, &ad5820_ctrl_ops,
V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0);
+ v4l2_ctrl_new_std(&coil->ctrls, &ad5820_ctrl_ops,
+ V4L2_CID_VOICE_COIL_CURRENT, 0, 1023, 1, 0);
if (coil->ctrls.error)
return coil->ctrls.error;
diff --git a/include/uapi/linux/v4l2-controls.h b/include/uapi/linux/v4l2-controls.h
index 0d2e1e0..c1efbc5 100644
--- a/include/uapi/linux/v4l2-controls.h
+++ b/include/uapi/linux/v4l2-controls.h
@@ -62,7 +62,7 @@
#define V4L2_CTRL_CLASS_FM_RX 0x00a10000 /* FM Receiver controls */
#define V4L2_CTRL_CLASS_RF_TUNER 0x00a20000 /* RF tuner controls */
#define V4L2_CTRL_CLASS_DETECT 0x00a30000 /* Detection controls */
-
+#define V4L2_CTRL_CLASS_VOICE_COIL 0x00a40000 /* Voice coil lens driver controls */
/* User-class control IDs */
#define V4L2_CID_BASE (V4L2_CTRL_CLASS_USER | 0x900)
@@ -894,6 +894,13 @@ enum v4l2_jpeg_chroma_subsampling {
#define V4L2_CID_TEST_PATTERN (V4L2_CID_IMAGE_PROC_CLASS_BASE + 3)
#define V4L2_CID_DEINTERLACING_MODE (V4L2_CID_IMAGE_PROC_CLASS_BASE + 4)
+/* Voice coil lens driver controls */
+
+#define V4L2_CID_VOICE_COIL_CLASS_BASE (V4L2_CTRL_CLASS_VOICE_COIL | 0x900)
+#define V4L2_CID_VOICE_COIL_CLASS (V4L2_CTRL_CLASS_VOICE_COIL | 1)
+
+#define V4L2_CID_VOICE_COIL_CURRENT (V4L2_CID_VOICE_COIL_CLASS_BASE + 1)
+
/* DV-class control IDs defined by V4L2 */
#define V4L2_CID_DV_CLASS_BASE (V4L2_CTRL_CLASS_DV | 0x900)
--
2.7.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* [PATCH v2 2/2] ad5820: Use VOICE_COIL_CURRENT control
2017-02-14 12:03 v4l: Add camera voice coil lens control class, current control Sakari Ailus
2017-02-14 12:03 ` [PATCH v2 1/2] " Sakari Ailus
@ 2017-02-14 12:03 ` Sakari Ailus
1 sibling, 0 replies; 3+ messages in thread
From: Sakari Ailus @ 2017-02-14 12:03 UTC (permalink / raw)
To: linux-media; +Cc: pavel
Add V4L2_CID_VOICE_COIL_CURRENT control support to the ad5820 driver. The
usage of the control is equivalent to how V4L2_CID_FOCUS_ABSOLUTE was used
by the driver. The old control remains supported.
Signed-off-by: Sakari Ailus <sakari.ailus@linux.intel.com>
---
drivers/media/i2c/ad5820.c | 28 ++++++++++++++++++++--------
1 file changed, 20 insertions(+), 8 deletions(-)
diff --git a/drivers/media/i2c/ad5820.c b/drivers/media/i2c/ad5820.c
index 7167b26..e5ff1a2 100644
--- a/drivers/media/i2c/ad5820.c
+++ b/drivers/media/i2c/ad5820.c
@@ -51,7 +51,7 @@ struct ad5820_device {
struct regulator *vana;
struct v4l2_ctrl_handler ctrls;
- u32 focus_absolute;
+ struct v4l2_ctrl *focus, *curr;
u32 focus_ramp_time;
u32 focus_ramp_mode;
@@ -59,6 +59,7 @@ struct ad5820_device {
int power_count;
bool standby;
+ bool in_set_ctrl;
};
static int ad5820_write(struct ad5820_device *coil, u16 data)
@@ -98,7 +99,7 @@ static int ad5820_update_hw(struct ad5820_device *coil)
status = RAMP_US_TO_CODE(coil->focus_ramp_time);
status |= coil->focus_ramp_mode
? AD5820_RAMP_MODE_64_16 : AD5820_RAMP_MODE_LINEAR;
- status |= coil->focus_absolute << AD5820_DAC_SHIFT;
+ status |= coil->curr->val << AD5820_DAC_SHIFT;
if (coil->standby)
status |= AD5820_POWER_DOWN;
@@ -160,10 +161,16 @@ static int ad5820_set_ctrl(struct v4l2_ctrl *ctrl)
struct ad5820_device *coil =
container_of(ctrl->handler, struct ad5820_device, ctrls);
+ if (coil->in_set_ctrl)
+ return 0;
+
switch (ctrl->id) {
case V4L2_CID_FOCUS_ABSOLUTE:
case V4L2_CID_VOICE_COIL_CURRENT:
- coil->focus_absolute = ctrl->val;
+ coil->in_set_ctrl = true;
+ __v4l2_ctrl_s_ctrl(ctrl == coil->focus ?
+ coil->curr : coil->focus, ctrl->val);
+ coil->in_set_ctrl = false;
return ad5820_update_hw(coil);
}
@@ -190,16 +197,21 @@ static int ad5820_init_controls(struct ad5820_device *coil)
* will just use abstract codes here. In any case, smaller value = focus
* position farther from camera. The default zero value means focus at
* infinity, and also least current consumption.
+ *
+ * The two controls below control the current. The
+ * FOCUS_ABSOLUTE is there for compatibility with old user
+ * space whereas the VOICE_COIL_CURRENT should be used by both
+ * new applications and drivers.
*/
- v4l2_ctrl_new_std(&coil->ctrls, &ad5820_ctrl_ops,
- V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0);
- v4l2_ctrl_new_std(&coil->ctrls, &ad5820_ctrl_ops,
- V4L2_CID_VOICE_COIL_CURRENT, 0, 1023, 1, 0);
+ coil->focus = v4l2_ctrl_new_std(&coil->ctrls, &ad5820_ctrl_ops,
+ V4L2_CID_FOCUS_ABSOLUTE, 0, 1023, 1, 0);
+ coil->curr = v4l2_ctrl_new_std(&coil->ctrls, &ad5820_ctrl_ops,
+ V4L2_CID_VOICE_COIL_CURRENT,
+ 0, 1023, 1, 0);
if (coil->ctrls.error)
return coil->ctrls.error;
- coil->focus_absolute = 0;
coil->focus_ramp_time = 0;
coil->focus_ramp_mode = 0;
--
2.7.4
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