V4L/DVB (9712): gspca:Subdriver ov534 added.

The OmniVision OV534 is the USB bridge chip used in Sony Playstation EYE,
it is found also in other webcams like Hercules Blog Webcam and
Hercules Dualpix HD.
This driver is the port to gspca of a prototype driver by Mark Ferrell
based on vivi. The original code to initialize the camera and start the
capture is from Jim Paris on ps2dev.org, here integrated with the analysis
of the USB communications taken by the windows driver.

Signed-off-by: Antonio Ospite <ospite@studenti.unina.it>
Signed-off-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

3 files changed, 517 insertions, 0 deletions

diff --git a/drivers/media/video/gspca/Kconfig b/drivers/media/video/gspca/Kconfig
index fdd4f653753..770fb699d04 100644
--- a/drivers/media/video/gspca/Kconfig
+++ b/drivers/media/video/gspca/Kconfig
@@ -64,6 +64,16 @@ config USB_GSPCA_OV519
 	  To compile this driver as a module, choose M here: the
 	  module will be called gspca_ov519.
 
+config USB_GSPCA_OV534
+	tristate "OV534 USB Camera Driver"
+	depends on VIDEO_V4L2 && USB_GSPCA
+	help
+	  Say Y here if you want support for cameras based on the OV534 chip.
+	  (e.g. Sony Playstation EYE)
+
+	  To compile this driver as a module, choose M here: the
+	  module will be called gspca_ov534.
+
 config USB_GSPCA_PAC207
 	tristate "Pixart PAC207 USB Camera Driver"
 	depends on VIDEO_V4L2 && USB_GSPCA
diff --git a/drivers/media/video/gspca/Makefile b/drivers/media/video/gspca/Makefile
index 22734f5a6c3..6c8046e232c 100644
--- a/drivers/media/video/gspca/Makefile
+++ b/drivers/media/video/gspca/Makefile
@@ -4,6 +4,7 @@ obj-$(CONFIG_USB_GSPCA_ETOMS)	+= gspca_etoms.o
 obj-$(CONFIG_USB_GSPCA_FINEPIX)	+= gspca_finepix.o
 obj-$(CONFIG_USB_GSPCA_MARS)	+= gspca_mars.o
 obj-$(CONFIG_USB_GSPCA_OV519)	+= gspca_ov519.o
+obj-$(CONFIG_USB_GSPCA_OV534)	+= gspca_ov534.o
 obj-$(CONFIG_USB_GSPCA_PAC207)	+= gspca_pac207.o
 obj-$(CONFIG_USB_GSPCA_PAC7311) += gspca_pac7311.o
 obj-$(CONFIG_USB_GSPCA_SONIXB)	+= gspca_sonixb.o
@@ -27,6 +28,7 @@ gspca_etoms-objs		:= etoms.o
 gspca_finepix-objs		:= finepix.o
 gspca_mars-objs			:= mars.o
 gspca_ov519-objs		:= ov519.o
+gspca_ov534-objs		:= ov534.o
 gspca_pac207-objs		:= pac207.o
 gspca_pac7311-objs		:= pac7311.o
 gspca_sonixb-objs		:= sonixb.o
diff --git a/drivers/media/video/gspca/ov534.c b/drivers/media/video/gspca/ov534.c
new file mode 100644
index 00000000000..a574be09bd4
--- /dev/null
+++ b/drivers/media/video/gspca/ov534.c
@@ -0,0 +1,505 @@
+/*
+ * ov534/ov772x gspca driver
+ * Copyright (C) 2008 Antonio Ospite <ospite@studenti.unina.it>
+ *
+ * Based on a prototype written by Mark Ferrell <majortrips@gmail.com>
+ * USB protocol reverse engineered by Jim Paris <jim@jtan.com>
+ * https://jim.sh/svn/jim/devl/playstation/ps3/eye/test/
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#define MODULE_NAME "ov534"
+
+#include "gspca.h"
+
+#define OV534_REG_ADDRESS	0xf1	/* ? */
+#define OV534_REG_SUBADDR	0xf2
+#define OV534_REG_WRITE		0xf3
+#define OV534_REG_READ		0xf4
+#define OV534_REG_OPERATION	0xf5
+#define OV534_REG_STATUS	0xf6
+
+#define OV534_OP_WRITE_3	0x37
+#define OV534_OP_WRITE_2	0x33
+#define OV534_OP_READ_2		0xf9
+
+#define CTRL_TIMEOUT 500
+
+MODULE_AUTHOR("Antonio Ospite <ospite@studenti.unina.it>");
+MODULE_DESCRIPTION("GSPCA/OV534 USB Camera Driver");
+MODULE_LICENSE("GPL");
+
+/* global parameters */
+static int frame_rate;
+
+/* specific webcam descriptor */
+struct sd {
+	struct gspca_dev gspca_dev;	/* !! must be the first item */
+	__u8 frame_rate;
+};
+
+/* V4L2 controls supported by the driver */
+static struct ctrl sd_ctrls[] = {
+};
+
+static struct v4l2_pix_format vga_mode[] = {
+	{640, 480, V4L2_PIX_FMT_YUYV, V4L2_FIELD_NONE,
+	 .bytesperline = 640 * 2,
+	 .sizeimage = 640 * 480 * 2,
+	 .colorspace = V4L2_COLORSPACE_JPEG,
+	 .priv = 0},
+};
+
+static void ov534_reg_write(struct usb_device *udev, u16 reg, u16 val)
+{
+	u16 data = val;
+	int ret;
+
+	PDEBUG(D_USBO, "reg=0x%04x, val=0%04x", reg, val);
+	ret = usb_control_msg(udev,
+			      usb_sndctrlpipe(udev, 0),
+			      0x1,
+			      USB_DIR_OUT | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+			      0x0, reg, &data, 1, CTRL_TIMEOUT);
+	if (ret < 0)
+		PDEBUG(D_ERR, "write failed");
+}
+
+static u16 ov534_reg_read(struct usb_device *udev, u16 reg)
+{
+	u16 data;
+	int ret;
+
+	ret = usb_control_msg(udev,
+			      usb_rcvctrlpipe(udev, 0),
+			      0x1,
+			      USB_DIR_IN | USB_TYPE_VENDOR | USB_RECIP_DEVICE,
+			      0x0, reg, &data, 1, CTRL_TIMEOUT);
+	PDEBUG(D_USBI, "reg=0x%04x, data=0x%04x", reg, data);
+	if (ret < 0)
+		PDEBUG(D_ERR, "read failed");
+	return data;
+}
+
+static void ov534_reg_verify_write(struct usb_device *udev, u16 reg, u16 val)
+{
+	u16 data;
+
+	ov534_reg_write(udev, reg, val);
+	data = ov534_reg_read(udev, reg);
+	if (data != val) {
+		PDEBUG(D_ERR | D_USBO,
+		       "unexpected result from read: 0x%04x != 0x%04x", val,
+		       data);
+	}
+}
+
+/* Two bits control LED: 0x21 bit 7 and 0x23 bit 7.
+ * (direction and output)? */
+static void ov534_set_led(struct usb_device *udev, int status)
+{
+	u16 data;
+
+	PDEBUG(D_CONF, "led status: %d", status);
+
+	data = ov534_reg_read(udev, 0x21);
+	data |= 0x80;
+	ov534_reg_write(udev, 0x21, data);
+
+	data = ov534_reg_read(udev, 0x23);
+	if (status)
+		data |= 0x80;
+	else
+		data &= ~(0x80);
+
+	ov534_reg_write(udev, 0x23, data);
+}
+
+static int sccb_check_status(struct usb_device *udev)
+{
+	u16 data;
+	int i;
+
+	for (i = 0; i < 5; i++) {
+		data = ov534_reg_read(udev, OV534_REG_STATUS);
+
+		switch (data & 0xFF) {
+		case 0x00:
+			return 1;
+		case 0x04:
+			return 0;
+		case 0x03:
+			break;
+		default:
+			PDEBUG(D_ERR, "sccb status 0x%02x, attempt %d/5\n",
+			       data, i + 1);
+		}
+	}
+	return 0;
+}
+
+static void sccb_reg_write(struct usb_device *udev, u16 reg, u16 val)
+{
+	PDEBUG(D_USBO, "reg: 0x%04x, val: 0x%04x", reg, val);
+	ov534_reg_write(udev, OV534_REG_SUBADDR, reg);
+	ov534_reg_write(udev, OV534_REG_WRITE, val);
+	ov534_reg_write(udev, OV534_REG_OPERATION, OV534_OP_WRITE_3);
+
+	if (!sccb_check_status(udev))
+		PDEBUG(D_ERR, "sccb_reg_write failed");
+}
+
+/* setup method */
+static void ov534_setup(struct usb_device *udev)
+{
+	ov534_reg_verify_write(udev, 0xe7, 0x3a);
+
+	ov534_reg_write(udev, OV534_REG_ADDRESS, 0x60);
+	ov534_reg_write(udev, OV534_REG_ADDRESS, 0x60);
+	ov534_reg_write(udev, OV534_REG_ADDRESS, 0x60);
+	ov534_reg_write(udev, OV534_REG_ADDRESS, 0x42);
+
+	ov534_reg_verify_write(udev, 0xc2, 0x0c);
+	ov534_reg_verify_write(udev, 0x88, 0xf8);
+	ov534_reg_verify_write(udev, 0xc3, 0x69);
+	ov534_reg_verify_write(udev, 0x89, 0xff);
+	ov534_reg_verify_write(udev, 0x76, 0x03);
+	ov534_reg_verify_write(udev, 0x92, 0x01);
+	ov534_reg_verify_write(udev, 0x93, 0x18);
+	ov534_reg_verify_write(udev, 0x94, 0x10);
+	ov534_reg_verify_write(udev, 0x95, 0x10);
+	ov534_reg_verify_write(udev, 0xe2, 0x00);
+	ov534_reg_verify_write(udev, 0xe7, 0x3e);
+
+	ov534_reg_write(udev, 0x1c, 0x0a);
+	ov534_reg_write(udev, 0x1d, 0x22);
+	ov534_reg_write(udev, 0x1d, 0x06);
+
+	ov534_reg_verify_write(udev, 0x96, 0x00);
+
+	ov534_reg_write(udev, 0x97, 0x20);
+	ov534_reg_write(udev, 0x97, 0x20);
+	ov534_reg_write(udev, 0x97, 0x20);
+	ov534_reg_write(udev, 0x97, 0x0a);
+	ov534_reg_write(udev, 0x97, 0x3f);
+	ov534_reg_write(udev, 0x97, 0x4a);
+	ov534_reg_write(udev, 0x97, 0x20);
+	ov534_reg_write(udev, 0x97, 0x15);
+	ov534_reg_write(udev, 0x97, 0x0b);
+
+	ov534_reg_verify_write(udev, 0x8e, 0x40);
+	ov534_reg_verify_write(udev, 0x1f, 0x81);
+	ov534_reg_verify_write(udev, 0x34, 0x05);
+	ov534_reg_verify_write(udev, 0xe3, 0x04);
+	ov534_reg_verify_write(udev, 0x88, 0x00);
+	ov534_reg_verify_write(udev, 0x89, 0x00);
+	ov534_reg_verify_write(udev, 0x76, 0x00);
+	ov534_reg_verify_write(udev, 0xe7, 0x2e);
+	ov534_reg_verify_write(udev, 0x31, 0xf9);
+	ov534_reg_verify_write(udev, 0x25, 0x42);
+	ov534_reg_verify_write(udev, 0x21, 0xf0);
+
+	ov534_reg_write(udev, 0x1c, 0x00);
+	ov534_reg_write(udev, 0x1d, 0x40);
+	ov534_reg_write(udev, 0x1d, 0x02);
+	ov534_reg_write(udev, 0x1d, 0x00);
+	ov534_reg_write(udev, 0x1d, 0x02);
+	ov534_reg_write(udev, 0x1d, 0x57);
+	ov534_reg_write(udev, 0x1d, 0xff);
+
+	ov534_reg_verify_write(udev, 0x8d, 0x1c);
+	ov534_reg_verify_write(udev, 0x8e, 0x80);
+	ov534_reg_verify_write(udev, 0xe5, 0x04);
+
+	ov534_set_led(udev, 1);
+
+	sccb_reg_write(udev, 0x12, 0x80);
+	sccb_reg_write(udev, 0x11, 0x01);
+	sccb_reg_write(udev, 0x11, 0x01);
+	sccb_reg_write(udev, 0x11, 0x01);
+	sccb_reg_write(udev, 0x11, 0x01);
+	sccb_reg_write(udev, 0x11, 0x01);
+	sccb_reg_write(udev, 0x11, 0x01);
+	sccb_reg_write(udev, 0x11, 0x01);
+	sccb_reg_write(udev, 0x11, 0x01);
+	sccb_reg_write(udev, 0x11, 0x01);
+	sccb_reg_write(udev, 0x11, 0x01);
+	sccb_reg_write(udev, 0x11, 0x01);
+
+	ov534_set_led(udev, 0);
+
+	sccb_reg_write(udev, 0x3d, 0x03);
+	sccb_reg_write(udev, 0x17, 0x26);
+	sccb_reg_write(udev, 0x18, 0xa0);
+	sccb_reg_write(udev, 0x19, 0x07);
+	sccb_reg_write(udev, 0x1a, 0xf0);
+	sccb_reg_write(udev, 0x32, 0x00);
+	sccb_reg_write(udev, 0x29, 0xa0);
+	sccb_reg_write(udev, 0x2c, 0xf0);
+	sccb_reg_write(udev, 0x65, 0x20);
+	sccb_reg_write(udev, 0x11, 0x01);
+	sccb_reg_write(udev, 0x42, 0x7f);
+	sccb_reg_write(udev, 0x63, 0xe0);
+	sccb_reg_write(udev, 0x64, 0xff);
+	sccb_reg_write(udev, 0x66, 0x00);
+	sccb_reg_write(udev, 0x13, 0xf0);
+	sccb_reg_write(udev, 0x0d, 0x41);
+	sccb_reg_write(udev, 0x0f, 0xc5);
+	sccb_reg_write(udev, 0x14, 0x11);
+
+	ov534_set_led(udev, 1);
+
+	sccb_reg_write(udev, 0x22, 0x7f);
+	sccb_reg_write(udev, 0x23, 0x03);
+	sccb_reg_write(udev, 0x24, 0x40);
+	sccb_reg_write(udev, 0x25, 0x30);
+	sccb_reg_write(udev, 0x26, 0xa1);
+	sccb_reg_write(udev, 0x2a, 0x00);
+	sccb_reg_write(udev, 0x2b, 0x00);
+	sccb_reg_write(udev, 0x6b, 0xaa);
+	sccb_reg_write(udev, 0x13, 0xff);
+
+	ov534_set_led(udev, 0);
+
+	sccb_reg_write(udev, 0x90, 0x05);
+	sccb_reg_write(udev, 0x91, 0x01);
+	sccb_reg_write(udev, 0x92, 0x03);
+	sccb_reg_write(udev, 0x93, 0x00);
+	sccb_reg_write(udev, 0x94, 0x60);
+	sccb_reg_write(udev, 0x95, 0x3c);
+	sccb_reg_write(udev, 0x96, 0x24);
+	sccb_reg_write(udev, 0x97, 0x1e);
+	sccb_reg_write(udev, 0x98, 0x62);
+	sccb_reg_write(udev, 0x99, 0x80);
+	sccb_reg_write(udev, 0x9a, 0x1e);
+	sccb_reg_write(udev, 0x9b, 0x08);
+	sccb_reg_write(udev, 0x9c, 0x20);
+	sccb_reg_write(udev, 0x9e, 0x81);
+
+	ov534_set_led(udev, 1);
+
+	sccb_reg_write(udev, 0xa6, 0x04);
+	sccb_reg_write(udev, 0x7e, 0x0c);
+	sccb_reg_write(udev, 0x7f, 0x16);
+	sccb_reg_write(udev, 0x80, 0x2a);
+	sccb_reg_write(udev, 0x81, 0x4e);
+	sccb_reg_write(udev, 0x82, 0x61);
+	sccb_reg_write(udev, 0x83, 0x6f);
+	sccb_reg_write(udev, 0x84, 0x7b);
+	sccb_reg_write(udev, 0x85, 0x86);
+	sccb_reg_write(udev, 0x86, 0x8e);
+	sccb_reg_write(udev, 0x87, 0x97);
+	sccb_reg_write(udev, 0x88, 0xa4);
+	sccb_reg_write(udev, 0x89, 0xaf);
+	sccb_reg_write(udev, 0x8a, 0xc5);
+	sccb_reg_write(udev, 0x8b, 0xd7);
+	sccb_reg_write(udev, 0x8c, 0xe8);
+	sccb_reg_write(udev, 0x8d, 0x20);
+
+	sccb_reg_write(udev, 0x0c, 0x90);
+
+	ov534_reg_verify_write(udev, 0xc0, 0x50);
+	ov534_reg_verify_write(udev, 0xc1, 0x3c);
+	ov534_reg_verify_write(udev, 0xc2, 0x0c);
+
+	ov534_set_led(udev, 1);
+
+	sccb_reg_write(udev, 0x2b, 0x00);
+	sccb_reg_write(udev, 0x22, 0x7f);
+	sccb_reg_write(udev, 0x23, 0x03);
+	sccb_reg_write(udev, 0x11, 0x01);
+	sccb_reg_write(udev, 0x0c, 0xd0);
+	sccb_reg_write(udev, 0x64, 0xff);
+	sccb_reg_write(udev, 0x0d, 0x41);
+
+	sccb_reg_write(udev, 0x14, 0x41);
+	sccb_reg_write(udev, 0x0e, 0xcd);
+	sccb_reg_write(udev, 0xac, 0xbf);
+	sccb_reg_write(udev, 0x8e, 0x00);
+	sccb_reg_write(udev, 0x0c, 0xd0);
+
+	ov534_reg_write(udev, 0xe0, 0x09);
+	ov534_set_led(udev, 0);
+}
+
+/* this function is called at probe time */
+static int sd_config(struct gspca_dev *gspca_dev,
+		     const struct usb_device_id *id)
+{
+	struct cam *cam;
+
+	cam = &gspca_dev->cam;
+
+	cam->epaddr = 0x01;
+	cam->cam_mode = vga_mode;
+	cam->nmodes = ARRAY_SIZE(vga_mode);
+
+	cam->bulk_size = vga_mode[0].sizeimage;
+	cam->bulk_nurbs = 2;
+
+	PDEBUG(D_PROBE, "bulk_size = %d", cam->bulk_size);
+
+	return 0;
+}
+
+/* this function is called at probe and resume time */
+static int sd_init(struct gspca_dev *gspca_dev)
+{
+	struct sd *sd = (struct sd *)gspca_dev;
+	ov534_setup(gspca_dev->dev);
+
+	if (frame_rate > 0)
+		sd->frame_rate = frame_rate;
+
+	PDEBUG(D_PROBE, "frame_rate = %d", sd->frame_rate);
+
+	switch (sd->frame_rate) {
+	case 50:
+		sccb_reg_write(gspca_dev->dev, 0x11, 0x01);
+		sccb_check_status(gspca_dev->dev);
+		sccb_reg_write(gspca_dev->dev, 0x0d, 0x41);
+		sccb_check_status(gspca_dev->dev);
+		ov534_reg_verify_write(gspca_dev->dev, 0xe5, 0x02);
+		break;
+	case 40:
+		sccb_reg_write(gspca_dev->dev, 0x11, 0x02);
+		sccb_check_status(gspca_dev->dev);
+		sccb_reg_write(gspca_dev->dev, 0x0d, 0xc1);
+		sccb_check_status(gspca_dev->dev);
+		ov534_reg_verify_write(gspca_dev->dev, 0xe5, 0x04);
+		break;
+	case 30:
+	default:
+		sccb_reg_write(gspca_dev->dev, 0x11, 0x04);
+		sccb_check_status(gspca_dev->dev);
+		sccb_reg_write(gspca_dev->dev, 0x0d, 0x81);
+		sccb_check_status(gspca_dev->dev);
+		ov534_reg_verify_write(gspca_dev->dev, 0xe5, 0x02);
+		break;
+	case 15:
+		sccb_reg_write(gspca_dev->dev, 0x11, 0x03);
+		sccb_check_status(gspca_dev->dev);
+		sccb_reg_write(gspca_dev->dev, 0x0d, 0x41);
+		sccb_check_status(gspca_dev->dev);
+		ov534_reg_verify_write(gspca_dev->dev, 0xe5, 0x04);
+		break;
+	};
+
+	return 0;
+}
+
+static int sd_start(struct gspca_dev *gspca_dev)
+{
+	PDEBUG(D_PROBE, "width = %d, height = %d",
+	       gspca_dev->width, gspca_dev->height);
+
+	gspca_dev->cam.bulk_size = gspca_dev->width * gspca_dev->height * 2;
+
+	/* start streaming data */
+	ov534_set_led(gspca_dev->dev, 1);
+	ov534_reg_write(gspca_dev->dev, 0xe0, 0x00);
+
+	return 0;
+}
+
+static void sd_stopN(struct gspca_dev *gspca_dev)
+{
+	/* stop streaming data */
+	ov534_reg_write(gspca_dev->dev, 0xe0, 0x09);
+	ov534_set_led(gspca_dev->dev, 0);
+}
+
+static void sd_pkt_scan(struct gspca_dev *gspca_dev, struct gspca_frame *frame,
+			__u8 *data, int len)
+{
+	/*
+	 * The current camera setup doesn't stream the last pixel, so we set it
+	 * to a dummy value
+	 */
+	__u8 last_pixel[4] = { 0, 0, 0, 0 };
+	int framesize = gspca_dev->cam.bulk_size;
+
+	if (len == framesize - 4) {
+		frame =
+		    gspca_frame_add(gspca_dev, FIRST_PACKET, frame, data, len);
+		frame =
+		    gspca_frame_add(gspca_dev, LAST_PACKET, frame, last_pixel,
+				    4);
+	} else
+		PDEBUG(D_PACK, "packet len = %d, framesize = %d", len,
+		       framesize);
+}
+
+/* sub-driver description */
+static const struct sd_desc sd_desc = {
+	.name     = MODULE_NAME,
+	.ctrls    = sd_ctrls,
+	.nctrls   = ARRAY_SIZE(sd_ctrls),
+	.config   = sd_config,
+	.init     = sd_init,
+	.start    = sd_start,
+	.stopN    = sd_stopN,
+	.pkt_scan = sd_pkt_scan,
+};
+
+/* -- module initialisation -- */
+static const __devinitdata struct usb_device_id device_table[] = {
+	{USB_DEVICE(0x06f8, 0x3002)},	/* Hercules Blog Webcam */
+	{USB_DEVICE(0x06f8, 0x3003)},	/* Hercules Dualpix HD Weblog */
+	{USB_DEVICE(0x1415, 0x2000)},	/* Sony HD Eye for PS3 (SLEH 00201) */
+	{}
+};
+
+MODULE_DEVICE_TABLE(usb, device_table);
+
+/* -- device connect -- */
+static int sd_probe(struct usb_interface *intf, const struct usb_device_id *id)
+{
+	return gspca_dev_probe(intf, id, &sd_desc, sizeof(struct sd),
+			       THIS_MODULE);
+}
+
+static struct usb_driver sd_driver = {
+	.name       = MODULE_NAME,
+	.id_table   = device_table,
+	.probe      = sd_probe,
+	.disconnect = gspca_disconnect,
+#ifdef CONFIG_PM
+	.suspend    = gspca_suspend,
+	.resume     = gspca_resume,
+#endif
+};
+
+/* -- module insert / remove -- */
+static int __init sd_mod_init(void)
+{
+	if (usb_register(&sd_driver) < 0)
+		return -1;
+	PDEBUG(D_PROBE, "registered");
+	return 0;
+}
+
+static void __exit sd_mod_exit(void)
+{
+	usb_deregister(&sd_driver);
+	PDEBUG(D_PROBE, "deregistered");
+}
+
+module_init(sd_mod_init);
+module_exit(sd_mod_exit);
+
+module_param(frame_rate, int, 0644);
+MODULE_PARM_DESC(frame_rate, "Frame rate (15, 30, 40, 50)");