@@ -97,6 +97,10 @@
#define OV9282_REG_MIPI_CTRL00 0x4800
#define OV9282_GATED_CLOCK BIT(5)
+/* Flash/Strobe control registers */
+#define OV9282_REG_FLASH_DURATION 0x3925
+#define OV9282_FLASH_DURATION_DEFAULT 0x0000001A
+
/* Input clock rate */
#define OV9282_INCLK_RATE 24000000
@@ -193,6 +197,7 @@ struct ov9282_mode {
* @again_ctrl: Pointer to analog gain control
* @pixel_rate: Pointer to pixel rate control
* @flash_led_mode: Pointer to flash led mode control
+ * @flash_timeout: Pointer to flash timeout control
* @vblank: Vertical blanking in lines
* @noncontinuous_clock: Selection of CSI2 noncontinuous clock mode
* @cur_mode: Pointer to current selected sensor mode
@@ -216,6 +221,7 @@ struct ov9282 {
};
struct v4l2_ctrl *pixel_rate;
struct v4l2_ctrl *flash_led_mode;
+ struct v4l2_ctrl *flash_timeout;
u32 vblank;
bool noncontinuous_clock;
const struct ov9282_mode *cur_mode;
@@ -689,6 +695,24 @@ static int ov9282_set_ctrl_flash_led_mode(struct ov9282 *ov9282, int mode)
current_val);
}
+static int ov9282_set_ctrl_flash_timeout(struct ov9282 *ov9282, int value)
+{
+ /* Calculate "strobe_frame_span" increments from a given value (µs).
+ * This is quite tricky as "The step width of shift and span is
+ * programmable under system clock domain.", but it's not documented
+ * how to program this step width (at least in the datasheet available
+ * to the author at time of writing).
+ * The formula below is interpolated from different modes/framerates
+ * and should work quite well for most settings.
+ */
+ u32 val = value * 192 / (ov9282->cur_mode->width + ov9282->hblank_ctrl->val);
+
+ ov9282_write_reg(ov9282, OV9282_REG_FLASH_DURATION, 1, (val >> 24) & 0xff);
+ ov9282_write_reg(ov9282, OV9282_REG_FLASH_DURATION + 1, 1, (val >> 16) & 0xff);
+ ov9282_write_reg(ov9282, OV9282_REG_FLASH_DURATION + 2, 1, (val >> 8) & 0xff);
+ return ov9282_write_reg(ov9282, OV9282_REG_FLASH_DURATION + 3, 1, val & 0xff);
+}
+
/**
* ov9282_set_ctrl() - Set subdevice control
* @ctrl: pointer to v4l2_ctrl structure
@@ -758,6 +782,9 @@ static int ov9282_set_ctrl(struct v4l2_ctrl *ctrl)
case V4L2_CID_FLASH_LED_MODE:
ret = ov9282_set_ctrl_flash_led_mode(ov9282, ctrl->val);
break;
+ case V4L2_CID_FLASH_TIMEOUT:
+ ret = ov9282_set_ctrl_flash_timeout(ov9282, ctrl->val);
+ break;
default:
dev_err(ov9282->dev, "Invalid control %d", ctrl->id);
ret = -EINVAL;
@@ -1420,6 +1447,10 @@ static int ov9282_init_controls(struct ov9282 *ov9282)
(1 << V4L2_FLASH_LED_MODE_TORCH),
V4L2_FLASH_LED_MODE_NONE);
+ ov9282->flash_timeout = v4l2_ctrl_new_std(ctrl_hdlr, &ov9282_ctrl_ops,
+ V4L2_CID_FLASH_TIMEOUT,
+ 0, 13900, 1, 8);
+
ret = v4l2_fwnode_device_parse(ov9282->dev, &props);
if (!ret) {
/* Failure sets ctrl_hdlr->error, which we check afterwards anyway */
Add V4L2_CID_FLASH_TIMEOUT support using the "strobe_frame_span" feature of the sensor. This is implemented by transforming the given µs value by an interpolated formula to a "span step width" value and writing it to register PWM_CTRL_25, PWM_CTRL_26, PWM_CTRL_27, PWM_CTRL_28 (0x3925, 0x3926, 0x3927, 0x3928). The maximum control value is set to the period of the current framerate. This must be changed to a dynamic range as soon as this driver implements the set_frame_interval() pad operation. All register values are based on the OV9281 datasheet v1.53 (jan 2019) and tested using an ov9281 VisionComponents module. Signed-off-by: Richard Leitner <richard.leitner@linux.dev> --- drivers/media/i2c/ov9282.c | 31 +++++++++++++++++++++++++++++++ 1 file changed, 31 insertions(+)