drivers/media/usb/gspca/m5602/m5602_s5k83a.c - arm/linux - Git at Google

 /*
  * Driver for the s5k83a sensor
  *
  * Copyright (C) 2008 Erik Andrén
  * Copyright (C) 2007 Ilyes Gouta. Based on the m5603x Linux Driver Project.
  * Copyright (C) 2005 m5603x Linux Driver Project <m5602@x3ng.com.br>
  *
  * Portions of code to USB interface and ALi driver software,
  * Copyright (c) 2006 Willem Duinker
  * v4l2 interface modeled after the V4L2 driver
  * for SN9C10x PC Camera Controllers
  *
  * 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, version 2.
  *
  */

 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

 #include <linux/kthread.h>
 #include "m5602_s5k83a.h"

 static int s5k83a_s_ctrl(struct v4l2_ctrl *ctrl);

 static const struct v4l2_ctrl_ops s5k83a_ctrl_ops = {
 	.s_ctrl = s5k83a_s_ctrl,
 };

 static struct v4l2_pix_format s5k83a_modes[] = {
 	{
 		640,
 		480,
 		V4L2_PIX_FMT_SBGGR8,
 		V4L2_FIELD_NONE,
 		.sizeimage =
 			640 * 480,
 		.bytesperline = 640,
 		.colorspace = V4L2_COLORSPACE_SRGB,
 		.priv = 0
 	}
 };

 static const unsigned char preinit_s5k83a[][4] = {
 	{BRIDGE, M5602_XB_MCU_CLK_DIV, 0x02, 0x00},
 	{BRIDGE, M5602_XB_MCU_CLK_CTRL, 0xb0, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x00, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xb0, 0x00},
 	{BRIDGE, M5602_XB_ADC_CTRL, 0xc0, 0x00},
 	{BRIDGE, M5602_XB_SENSOR_TYPE, 0x0d, 0x00},
 	{BRIDGE, M5602_XB_SENSOR_CTRL, 0x00, 0x00},

 	{BRIDGE, M5602_XB_SIG_INI, 0x00, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DIR, 0x1d, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DAT, 0x08, 0x00},
 	{BRIDGE, M5602_XB_GPIO_EN_H, 0x3f, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DIR_H, 0x3f, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DAT_H, 0x00, 0x00},
 	{BRIDGE, M5602_XB_GPIO_EN_L, 0xff, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DIR_L, 0xff, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DAT_L, 0x00, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0xb0, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0x80, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x00, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xb0, 0x00},
 	{BRIDGE, M5602_XB_ADC_CTRL, 0xc0, 0x00},
 	{BRIDGE, M5602_XB_SENSOR_TYPE, 0x09, 0x00},
 	{BRIDGE, M5602_XB_MCU_CLK_DIV, 0x02, 0x00},
 	{BRIDGE, M5602_XB_MCU_CLK_CTRL, 0xb0, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x00, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xf0, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DIR, 0x1d, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DAT, 0x1c, 0x00},
 	{BRIDGE, M5602_XB_GPIO_EN_H, 0x06, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DIR_H, 0x06, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DAT_H, 0x00, 0x00},
 	{BRIDGE, M5602_XB_GPIO_EN_L, 0x00, 0x00},
 	{BRIDGE, M5602_XB_I2C_CLK_DIV, 0x20, 0x00},
 };

 /* This could probably be considerably shortened.
    I don't have the hardware to experiment with it, patches welcome
 */
 static const unsigned char init_s5k83a[][4] = {
 	/* The following sequence is useless after a clean boot
 	   but is necessary after resume from suspend */
 	{BRIDGE, M5602_XB_GPIO_DIR, 0x1d, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DAT, 0x08, 0x00},
 	{BRIDGE, M5602_XB_GPIO_EN_H, 0x3f, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DIR_H, 0x3f, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DAT_H, 0x00, 0x00},
 	{BRIDGE, M5602_XB_GPIO_EN_L, 0xff, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DIR_L, 0xff, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DAT_L, 0x00, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0xb0, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0x80, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x00, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xb0, 0x00},
 	{BRIDGE, M5602_XB_ADC_CTRL, 0xc0, 0x00},
 	{BRIDGE, M5602_XB_SENSOR_TYPE, 0x09, 0x00},
 	{BRIDGE, M5602_XB_MCU_CLK_DIV, 0x02, 0x00},
 	{BRIDGE, M5602_XB_MCU_CLK_CTRL, 0xb0, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x00, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xf0, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DIR, 0x1d, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DAT, 0x08, 0x00},
 	{BRIDGE, M5602_XB_GPIO_EN_H, 0x06, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DIR_H, 0x06, 0x00},
 	{BRIDGE, M5602_XB_GPIO_DAT_H, 0x00, 0x00},
 	{BRIDGE, M5602_XB_GPIO_EN_L, 0x00, 0x00},
 	{BRIDGE, M5602_XB_I2C_CLK_DIV, 0x20, 0x00},

 	{SENSOR, S5K83A_PAGE_MAP, 0x04, 0x00},
 	{SENSOR, 0xaf, 0x01, 0x00},
 	{SENSOR, S5K83A_PAGE_MAP, 0x00, 0x00},
 	{SENSOR, 0x7b, 0xff, 0x00},
 	{SENSOR, S5K83A_PAGE_MAP, 0x05, 0x00},
 	{SENSOR, 0x01, 0x50, 0x00},
 	{SENSOR, 0x12, 0x20, 0x00},
 	{SENSOR, 0x17, 0x40, 0x00},
 	{SENSOR, 0x1c, 0x00, 0x00},
 	{SENSOR, 0x02, 0x70, 0x00},
 	{SENSOR, 0x03, 0x0b, 0x00},
 	{SENSOR, 0x04, 0xf0, 0x00},
 	{SENSOR, 0x05, 0x0b, 0x00},
 	{SENSOR, 0x06, 0x71, 0x00},
 	{SENSOR, 0x07, 0xe8, 0x00}, /* 488 */
 	{SENSOR, 0x08, 0x02, 0x00},
 	{SENSOR, 0x09, 0x88, 0x00}, /* 648 */
 	{SENSOR, 0x14, 0x00, 0x00},
 	{SENSOR, 0x15, 0x20, 0x00}, /* 32 */
 	{SENSOR, 0x19, 0x00, 0x00},
 	{SENSOR, 0x1a, 0x98, 0x00}, /* 152 */
 	{SENSOR, 0x0f, 0x02, 0x00},
 	{SENSOR, 0x10, 0xe5, 0x00}, /* 741 */
 	/* normal colors
 	(this is value after boot, but after tries can be different) */
 	{SENSOR, 0x00, 0x06, 0x00},
 };

 static const unsigned char start_s5k83a[][4] = {
 	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x06, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xb0, 0x00},
 	{BRIDGE, M5602_XB_ADC_CTRL, 0xc0, 0x00},
 	{BRIDGE, M5602_XB_SENSOR_TYPE, 0x09, 0x00},
 	{BRIDGE, M5602_XB_LINE_OF_FRAME_H, 0x81, 0x00},
 	{BRIDGE, M5602_XB_PIX_OF_LINE_H, 0x82, 0x00},
 	{BRIDGE, M5602_XB_SIG_INI, 0x01, 0x00},
 	{BRIDGE, M5602_XB_VSYNC_PARA, 0x00, 0x00},
 	{BRIDGE, M5602_XB_VSYNC_PARA, 0x00, 0x00},
 	{BRIDGE, M5602_XB_VSYNC_PARA, 0x00, 0x00},
 	{BRIDGE, M5602_XB_VSYNC_PARA, 0x00, 0x00},
 	{BRIDGE, M5602_XB_VSYNC_PARA, 0x01, 0x00},
 	{BRIDGE, M5602_XB_VSYNC_PARA, 0xe4, 0x00}, /* 484 */
 	{BRIDGE, M5602_XB_VSYNC_PARA, 0x00, 0x00},
 	{BRIDGE, M5602_XB_VSYNC_PARA, 0x00, 0x00},
 	{BRIDGE, M5602_XB_SIG_INI, 0x00, 0x00},
 	{BRIDGE, M5602_XB_SIG_INI, 0x02, 0x00},
 	{BRIDGE, M5602_XB_HSYNC_PARA, 0x00, 0x00},
 	{BRIDGE, M5602_XB_HSYNC_PARA, 0x00, 0x00},
 	{BRIDGE, M5602_XB_HSYNC_PARA, 0x02, 0x00},
 	{BRIDGE, M5602_XB_HSYNC_PARA, 0x7f, 0x00}, /* 639 */
 	{BRIDGE, M5602_XB_SIG_INI, 0x00, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x00, 0x00},
 	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xb0, 0x00},
 };

 static void s5k83a_dump_registers(struct sd *sd);
 static int s5k83a_get_rotation(struct sd *sd, u8 *reg_data);
 static int s5k83a_set_led_indication(struct sd *sd, u8 val);
 static int s5k83a_set_flip_real(struct gspca_dev *gspca_dev,
 				__s32 vflip, __s32 hflip);

 int s5k83a_probe(struct sd *sd)
 {
 	u8 prod_id = 0, ver_id = 0;
 	int i, err = 0;
 	struct gspca_dev *gspca_dev = (struct gspca_dev *)sd;

 	if (force_sensor) {
 		if (force_sensor == S5K83A_SENSOR) {
 			pr_info("Forcing a %s sensor\n", s5k83a.name);
 			goto sensor_found;
 		}
 		/* If we want to force another sensor, don't try to probe this
 		 * one */
 		return -ENODEV;
 	}

 	PDEBUG(D_PROBE, "Probing for a s5k83a sensor");

 	/* Preinit the sensor */
 	for (i = 0; i < ARRAY_SIZE(preinit_s5k83a) && !err; i++) {
 		u8 data[2] = {preinit_s5k83a[i][2], preinit_s5k83a[i][3]};
 		if (preinit_s5k83a[i][0] == SENSOR)
 			err = m5602_write_sensor(sd, preinit_s5k83a[i][1],
 				data, 2);
 		else
 			err = m5602_write_bridge(sd, preinit_s5k83a[i][1],
 				data[0]);
 	}

 	/* We don't know what register (if any) that contain the product id
 	 * Just pick the first addresses that seem to produce the same results
 	 * on multiple machines */
 	if (m5602_read_sensor(sd, 0x00, &prod_id, 1))
 		return -ENODEV;

 	if (m5602_read_sensor(sd, 0x01, &ver_id, 1))
 		return -ENODEV;

 	if ((prod_id == 0xff) || (ver_id == 0xff))
 		return -ENODEV;
 	else
 		pr_info("Detected a s5k83a sensor\n");

 sensor_found:
 	sd->gspca_dev.cam.cam_mode = s5k83a_modes;
 	sd->gspca_dev.cam.nmodes = ARRAY_SIZE(s5k83a_modes);

 	/* null the pointer! thread is't running now */
 	sd->rotation_thread = NULL;

 	return 0;
 }

 int s5k83a_init(struct sd *sd)
 {
 	int i, err = 0;

 	for (i = 0; i < ARRAY_SIZE(init_s5k83a) && !err; i++) {
 		u8 data[2] = {0x00, 0x00};

 		switch (init_s5k83a[i][0]) {
 		case BRIDGE:
 			err = m5602_write_bridge(sd,
 					init_s5k83a[i][1],
 					init_s5k83a[i][2]);
 			break;

 		case SENSOR:
 			data[0] = init_s5k83a[i][2];
 			err = m5602_write_sensor(sd,
 				init_s5k83a[i][1], data, 1);
 			break;

 		case SENSOR_LONG:
 			data[0] = init_s5k83a[i][2];
 			data[1] = init_s5k83a[i][3];
 			err = m5602_write_sensor(sd,
 				init_s5k83a[i][1], data, 2);
 			break;
 		default:
 			pr_info("Invalid stream command, exiting init\n");
 			return -EINVAL;
 		}
 	}

 	if (dump_sensor)
 		s5k83a_dump_registers(sd);

 	return err;
 }

 int s5k83a_init_controls(struct sd *sd)
 {
 	struct v4l2_ctrl_handler *hdl = &sd->gspca_dev.ctrl_handler;

 	sd->gspca_dev.vdev.ctrl_handler = hdl;
 	v4l2_ctrl_handler_init(hdl, 6);

 	v4l2_ctrl_new_std(hdl, &s5k83a_ctrl_ops, V4L2_CID_BRIGHTNESS,
 			  0, 255, 1, S5K83A_DEFAULT_BRIGHTNESS);

 	v4l2_ctrl_new_std(hdl, &s5k83a_ctrl_ops, V4L2_CID_EXPOSURE,
 			  0, S5K83A_MAXIMUM_EXPOSURE, 1,
 			  S5K83A_DEFAULT_EXPOSURE);

 	v4l2_ctrl_new_std(hdl, &s5k83a_ctrl_ops, V4L2_CID_GAIN,
 			  0, 255, 1, S5K83A_DEFAULT_GAIN);

 	sd->hflip = v4l2_ctrl_new_std(hdl, &s5k83a_ctrl_ops, V4L2_CID_HFLIP,
 				      0, 1, 1, 0);
 	sd->vflip = v4l2_ctrl_new_std(hdl, &s5k83a_ctrl_ops, V4L2_CID_VFLIP,
 				      0, 1, 1, 0);

 	if (hdl->error) {
 		pr_err("Could not initialize controls\n");
 		return hdl->error;
 	}

 	v4l2_ctrl_cluster(2, &sd->hflip);

 	return 0;
 }

 static int rotation_thread_function(void *data)
 {
 	struct sd *sd = (struct sd *) data;
 	u8 reg, previous_rotation = 0;
 	__s32 vflip, hflip;

 	set_current_state(TASK_INTERRUPTIBLE);
 	while (!schedule_timeout(msecs_to_jiffies(100))) {
 		if (mutex_lock_interruptible(&sd->gspca_dev.usb_lock))
 			break;

 		s5k83a_get_rotation(sd, &reg);
 		if (previous_rotation != reg) {
 			previous_rotation = reg;
 			pr_info("Camera was flipped\n");

 			hflip = sd->hflip->val;
 			vflip = sd->vflip->val;

 			if (reg) {
 				vflip = !vflip;
 				hflip = !hflip;
 			}
 			s5k83a_set_flip_real((struct gspca_dev *) sd,
 					      vflip, hflip);
 		}

 		mutex_unlock(&sd->gspca_dev.usb_lock);
 		set_current_state(TASK_INTERRUPTIBLE);
 	}

 	/* return to "front" flip */
 	if (previous_rotation) {
 		hflip = sd->hflip->val;
 		vflip = sd->vflip->val;
 		s5k83a_set_flip_real((struct gspca_dev *) sd, vflip, hflip);
 	}

 	sd->rotation_thread = NULL;
 	return 0;
 }

 int s5k83a_start(struct sd *sd)
 {
 	int i, err = 0;

 	/* Create another thread, polling the GPIO ports of the camera to check
 	   if it got rotated. This is how the windows driver does it so we have
 	   to assume that there is no better way of accomplishing this */
 	sd->rotation_thread = kthread_create(rotation_thread_function,
 					     sd, "rotation thread");
 	if (IS_ERR(sd->rotation_thread)) {
 		err = PTR_ERR(sd->rotation_thread);
 		sd->rotation_thread = NULL;
 		return err;
 	}
 	wake_up_process(sd->rotation_thread);

 	/* Preinit the sensor */
 	for (i = 0; i < ARRAY_SIZE(start_s5k83a) && !err; i++) {
 		u8 data[2] = {start_s5k83a[i][2], start_s5k83a[i][3]};
 		if (start_s5k83a[i][0] == SENSOR)
 			err = m5602_write_sensor(sd, start_s5k83a[i][1],
 				data, 2);
 		else
 			err = m5602_write_bridge(sd, start_s5k83a[i][1],
 				data[0]);
 	}
 	if (err < 0)
 		return err;

 	return s5k83a_set_led_indication(sd, 1);
 }

 int s5k83a_stop(struct sd *sd)
 {
 	if (sd->rotation_thread)
 		kthread_stop(sd->rotation_thread);

 	return s5k83a_set_led_indication(sd, 0);
 }

 void s5k83a_disconnect(struct sd *sd)
 {
 	s5k83a_stop(sd);

 	sd->sensor = NULL;
 }

 static int s5k83a_set_gain(struct gspca_dev *gspca_dev, __s32 val)
 {
 	int err;
 	u8 data[2];
 	struct sd *sd = (struct sd *) gspca_dev;

 	data[0] = 0x00;
 	data[1] = 0x20;
 	err = m5602_write_sensor(sd, 0x14, data, 2);
 	if (err < 0)
 		return err;

 	data[0] = 0x01;
 	data[1] = 0x00;
 	err = m5602_write_sensor(sd, 0x0d, data, 2);
 	if (err < 0)
 		return err;

 	/* FIXME: This is not sane, we need to figure out the composition
 		  of these registers */
 	data[0] = val >> 3; /* gain, high 5 bits */
 	data[1] = val >> 1; /* gain, high 7 bits */
 	err = m5602_write_sensor(sd, S5K83A_GAIN, data, 2);

 	return err;
 }

 static int s5k83a_set_brightness(struct gspca_dev *gspca_dev, __s32 val)
 {
 	int err;
 	u8 data[1];
 	struct sd *sd = (struct sd *) gspca_dev;

 	data[0] = val;
 	err = m5602_write_sensor(sd, S5K83A_BRIGHTNESS, data, 1);
 	return err;
 }

 static int s5k83a_set_exposure(struct gspca_dev *gspca_dev, __s32 val)
 {
 	int err;
 	u8 data[2];
 	struct sd *sd = (struct sd *) gspca_dev;

 	data[0] = 0;
 	data[1] = val;
 	err = m5602_write_sensor(sd, S5K83A_EXPOSURE, data, 2);
 	return err;
 }

 static int s5k83a_set_flip_real(struct gspca_dev *gspca_dev,
 				__s32 vflip, __s32 hflip)
 {
 	int err;
 	u8 data[1];
 	struct sd *sd = (struct sd *) gspca_dev;

 	data[0] = 0x05;
 	err = m5602_write_sensor(sd, S5K83A_PAGE_MAP, data, 1);
 	if (err < 0)
 		return err;

 	/* six bit is vflip, seven is hflip */
 	data[0] = S5K83A_FLIP_MASK;
 	data[0] = (vflip) ? data[0] | 0x40 : data[0];
 	data[0] = (hflip) ? data[0] | 0x80 : data[0];

 	err = m5602_write_sensor(sd, S5K83A_FLIP, data, 1);
 	if (err < 0)
 		return err;

 	data[0] = (vflip) ? 0x0b : 0x0a;
 	err = m5602_write_sensor(sd, S5K83A_VFLIP_TUNE, data, 1);
 	if (err < 0)
 		return err;

 	data[0] = (hflip) ? 0x0a : 0x0b;
 	err = m5602_write_sensor(sd, S5K83A_HFLIP_TUNE, data, 1);
 	return err;
 }

 static int s5k83a_set_hvflip(struct gspca_dev *gspca_dev)
 {
 	int err;
 	u8 reg;
 	struct sd *sd = (struct sd *) gspca_dev;
 	int hflip = sd->hflip->val;
 	int vflip = sd->vflip->val;

 	err = s5k83a_get_rotation(sd, &reg);
 	if (err < 0)
 		return err;
 	if (reg) {
 		hflip = !hflip;
 		vflip = !vflip;
 	}

 	err = s5k83a_set_flip_real(gspca_dev, vflip, hflip);
 	return err;
 }

 static int s5k83a_s_ctrl(struct v4l2_ctrl *ctrl)
 {
 	struct gspca_dev *gspca_dev =
 		container_of(ctrl->handler, struct gspca_dev, ctrl_handler);
 	int err;

 	if (!gspca_dev->streaming)
 		return 0;

 	switch (ctrl->id) {
 	case V4L2_CID_BRIGHTNESS:
 		err = s5k83a_set_brightness(gspca_dev, ctrl->val);
 		break;
 	case V4L2_CID_EXPOSURE:
 		err = s5k83a_set_exposure(gspca_dev, ctrl->val);
 		break;
 	case V4L2_CID_GAIN:
 		err = s5k83a_set_gain(gspca_dev, ctrl->val);
 		break;
 	case V4L2_CID_HFLIP:
 		err = s5k83a_set_hvflip(gspca_dev);
 		break;
 	default:
 		return -EINVAL;
 	}

 	return err;
 }

 static int s5k83a_set_led_indication(struct sd *sd, u8 val)
 {
 	int err = 0;
 	u8 data[1];

 	err = m5602_read_bridge(sd, M5602_XB_GPIO_DAT, data);
 	if (err < 0)
 		return err;

 	if (val)
 		data[0] = data[0] | S5K83A_GPIO_LED_MASK;
 	else
 		data[0] = data[0] & ~S5K83A_GPIO_LED_MASK;

 	err = m5602_write_bridge(sd, M5602_XB_GPIO_DAT, data[0]);

 	return err;
 }

 /* Get camera rotation on Acer notebooks */
 static int s5k83a_get_rotation(struct sd *sd, u8 *reg_data)
 {
 	int err = m5602_read_bridge(sd, M5602_XB_GPIO_DAT, reg_data);
 	*reg_data = (*reg_data & S5K83A_GPIO_ROTATION_MASK) ? 0 : 1;
 	return err;
 }

 static void s5k83a_dump_registers(struct sd *sd)
 {
 	int address;
 	u8 page, old_page;
 	m5602_read_sensor(sd, S5K83A_PAGE_MAP, &old_page, 1);

 	for (page = 0; page < 16; page++) {
 		m5602_write_sensor(sd, S5K83A_PAGE_MAP, &page, 1);
 		pr_info("Dumping the s5k83a register state for page 0x%x\n",
 			page);
 		for (address = 0; address <= 0xff; address++) {
 			u8 val = 0;
 			m5602_read_sensor(sd, address, &val, 1);
 			pr_info("register 0x%x contains 0x%x\n", address, val);
 		}
 	}
 	pr_info("s5k83a register state dump complete\n");

 	for (page = 0; page < 16; page++) {
 		m5602_write_sensor(sd, S5K83A_PAGE_MAP, &page, 1);
 		pr_info("Probing for which registers that are read/write for page 0x%x\n",
 			page);
 		for (address = 0; address <= 0xff; address++) {
 			u8 old_val, ctrl_val, test_val = 0xff;

 			m5602_read_sensor(sd, address, &old_val, 1);
 			m5602_write_sensor(sd, address, &test_val, 1);
 			m5602_read_sensor(sd, address, &ctrl_val, 1);

 			if (ctrl_val == test_val)
 				pr_info("register 0x%x is writeable\n",
 					address);
 			else
 				pr_info("register 0x%x is read only\n",
 					address);

 			/* Restore original val */
 			m5602_write_sensor(sd, address, &old_val, 1);
 		}
 	}
 	pr_info("Read/write register probing complete\n");
 	m5602_write_sensor(sd, S5K83A_PAGE_MAP, &old_page, 1);
 }
	/*
	* Driver for the s5k83a sensor
	*
	* Copyright (C) 2008 Erik Andrén
	* Copyright (C) 2007 Ilyes Gouta. Based on the m5603x Linux Driver Project.
	* Copyright (C) 2005 m5603x Linux Driver Project <m5602@x3ng.com.br>
	*
	* Portions of code to USB interface and ALi driver software,
	* Copyright (c) 2006 Willem Duinker
	* v4l2 interface modeled after the V4L2 driver
	* for SN9C10x PC Camera Controllers
	*
	* 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, version 2.
	*
	*/

	#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

	#include <linux/kthread.h>
	#include "m5602_s5k83a.h"

	static int s5k83a_s_ctrl(struct v4l2_ctrl *ctrl);

	static const struct v4l2_ctrl_ops s5k83a_ctrl_ops = {
	.s_ctrl = s5k83a_s_ctrl,
	};

	static struct v4l2_pix_format s5k83a_modes[] = {
	{
	640,
	480,
	V4L2_PIX_FMT_SBGGR8,
	V4L2_FIELD_NONE,
	.sizeimage =
	640 * 480,
	.bytesperline = 640,
	.colorspace = V4L2_COLORSPACE_SRGB,
	.priv = 0
	}
	};

	static const unsigned char preinit_s5k83a[][4] = {
	{BRIDGE, M5602_XB_MCU_CLK_DIV, 0x02, 0x00},
	{BRIDGE, M5602_XB_MCU_CLK_CTRL, 0xb0, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x00, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xb0, 0x00},
	{BRIDGE, M5602_XB_ADC_CTRL, 0xc0, 0x00},
	{BRIDGE, M5602_XB_SENSOR_TYPE, 0x0d, 0x00},
	{BRIDGE, M5602_XB_SENSOR_CTRL, 0x00, 0x00},

	{BRIDGE, M5602_XB_SIG_INI, 0x00, 0x00},
	{BRIDGE, M5602_XB_GPIO_DIR, 0x1d, 0x00},
	{BRIDGE, M5602_XB_GPIO_DAT, 0x08, 0x00},
	{BRIDGE, M5602_XB_GPIO_EN_H, 0x3f, 0x00},
	{BRIDGE, M5602_XB_GPIO_DIR_H, 0x3f, 0x00},
	{BRIDGE, M5602_XB_GPIO_DAT_H, 0x00, 0x00},
	{BRIDGE, M5602_XB_GPIO_EN_L, 0xff, 0x00},
	{BRIDGE, M5602_XB_GPIO_DIR_L, 0xff, 0x00},
	{BRIDGE, M5602_XB_GPIO_DAT_L, 0x00, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0xb0, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0x80, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x00, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xb0, 0x00},
	{BRIDGE, M5602_XB_ADC_CTRL, 0xc0, 0x00},
	{BRIDGE, M5602_XB_SENSOR_TYPE, 0x09, 0x00},
	{BRIDGE, M5602_XB_MCU_CLK_DIV, 0x02, 0x00},
	{BRIDGE, M5602_XB_MCU_CLK_CTRL, 0xb0, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x00, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xf0, 0x00},
	{BRIDGE, M5602_XB_GPIO_DIR, 0x1d, 0x00},
	{BRIDGE, M5602_XB_GPIO_DAT, 0x1c, 0x00},
	{BRIDGE, M5602_XB_GPIO_EN_H, 0x06, 0x00},
	{BRIDGE, M5602_XB_GPIO_DIR_H, 0x06, 0x00},
	{BRIDGE, M5602_XB_GPIO_DAT_H, 0x00, 0x00},
	{BRIDGE, M5602_XB_GPIO_EN_L, 0x00, 0x00},
	{BRIDGE, M5602_XB_I2C_CLK_DIV, 0x20, 0x00},
	};

	/* This could probably be considerably shortened.
	I don't have the hardware to experiment with it, patches welcome
	*/
	static const unsigned char init_s5k83a[][4] = {
	/* The following sequence is useless after a clean boot
	but is necessary after resume from suspend */
	{BRIDGE, M5602_XB_GPIO_DIR, 0x1d, 0x00},
	{BRIDGE, M5602_XB_GPIO_DAT, 0x08, 0x00},
	{BRIDGE, M5602_XB_GPIO_EN_H, 0x3f, 0x00},
	{BRIDGE, M5602_XB_GPIO_DIR_H, 0x3f, 0x00},
	{BRIDGE, M5602_XB_GPIO_DAT_H, 0x00, 0x00},
	{BRIDGE, M5602_XB_GPIO_EN_L, 0xff, 0x00},
	{BRIDGE, M5602_XB_GPIO_DIR_L, 0xff, 0x00},
	{BRIDGE, M5602_XB_GPIO_DAT_L, 0x00, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0xb0, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0x80, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x00, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xb0, 0x00},
	{BRIDGE, M5602_XB_ADC_CTRL, 0xc0, 0x00},
	{BRIDGE, M5602_XB_SENSOR_TYPE, 0x09, 0x00},
	{BRIDGE, M5602_XB_MCU_CLK_DIV, 0x02, 0x00},
	{BRIDGE, M5602_XB_MCU_CLK_CTRL, 0xb0, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x00, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xf0, 0x00},
	{BRIDGE, M5602_XB_GPIO_DIR, 0x1d, 0x00},
	{BRIDGE, M5602_XB_GPIO_DAT, 0x08, 0x00},
	{BRIDGE, M5602_XB_GPIO_EN_H, 0x06, 0x00},
	{BRIDGE, M5602_XB_GPIO_DIR_H, 0x06, 0x00},
	{BRIDGE, M5602_XB_GPIO_DAT_H, 0x00, 0x00},
	{BRIDGE, M5602_XB_GPIO_EN_L, 0x00, 0x00},
	{BRIDGE, M5602_XB_I2C_CLK_DIV, 0x20, 0x00},

	{SENSOR, S5K83A_PAGE_MAP, 0x04, 0x00},
	{SENSOR, 0xaf, 0x01, 0x00},
	{SENSOR, S5K83A_PAGE_MAP, 0x00, 0x00},
	{SENSOR, 0x7b, 0xff, 0x00},
	{SENSOR, S5K83A_PAGE_MAP, 0x05, 0x00},
	{SENSOR, 0x01, 0x50, 0x00},
	{SENSOR, 0x12, 0x20, 0x00},
	{SENSOR, 0x17, 0x40, 0x00},
	{SENSOR, 0x1c, 0x00, 0x00},
	{SENSOR, 0x02, 0x70, 0x00},
	{SENSOR, 0x03, 0x0b, 0x00},
	{SENSOR, 0x04, 0xf0, 0x00},
	{SENSOR, 0x05, 0x0b, 0x00},
	{SENSOR, 0x06, 0x71, 0x00},
	{SENSOR, 0x07, 0xe8, 0x00}, /* 488 */
	{SENSOR, 0x08, 0x02, 0x00},
	{SENSOR, 0x09, 0x88, 0x00}, /* 648 */
	{SENSOR, 0x14, 0x00, 0x00},
	{SENSOR, 0x15, 0x20, 0x00}, /* 32 */
	{SENSOR, 0x19, 0x00, 0x00},
	{SENSOR, 0x1a, 0x98, 0x00}, /* 152 */
	{SENSOR, 0x0f, 0x02, 0x00},
	{SENSOR, 0x10, 0xe5, 0x00}, /* 741 */
	/* normal colors
	(this is value after boot, but after tries can be different) */
	{SENSOR, 0x00, 0x06, 0x00},
	};

	static const unsigned char start_s5k83a[][4] = {
	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x06, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xb0, 0x00},
	{BRIDGE, M5602_XB_ADC_CTRL, 0xc0, 0x00},
	{BRIDGE, M5602_XB_SENSOR_TYPE, 0x09, 0x00},
	{BRIDGE, M5602_XB_LINE_OF_FRAME_H, 0x81, 0x00},
	{BRIDGE, M5602_XB_PIX_OF_LINE_H, 0x82, 0x00},
	{BRIDGE, M5602_XB_SIG_INI, 0x01, 0x00},
	{BRIDGE, M5602_XB_VSYNC_PARA, 0x00, 0x00},
	{BRIDGE, M5602_XB_VSYNC_PARA, 0x00, 0x00},
	{BRIDGE, M5602_XB_VSYNC_PARA, 0x00, 0x00},
	{BRIDGE, M5602_XB_VSYNC_PARA, 0x00, 0x00},
	{BRIDGE, M5602_XB_VSYNC_PARA, 0x01, 0x00},
	{BRIDGE, M5602_XB_VSYNC_PARA, 0xe4, 0x00}, /* 484 */
	{BRIDGE, M5602_XB_VSYNC_PARA, 0x00, 0x00},
	{BRIDGE, M5602_XB_VSYNC_PARA, 0x00, 0x00},
	{BRIDGE, M5602_XB_SIG_INI, 0x00, 0x00},
	{BRIDGE, M5602_XB_SIG_INI, 0x02, 0x00},
	{BRIDGE, M5602_XB_HSYNC_PARA, 0x00, 0x00},
	{BRIDGE, M5602_XB_HSYNC_PARA, 0x00, 0x00},
	{BRIDGE, M5602_XB_HSYNC_PARA, 0x02, 0x00},
	{BRIDGE, M5602_XB_HSYNC_PARA, 0x7f, 0x00}, /* 639 */
	{BRIDGE, M5602_XB_SIG_INI, 0x00, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_DIV, 0x00, 0x00},
	{BRIDGE, M5602_XB_SEN_CLK_CTRL, 0xb0, 0x00},
	};

	static void s5k83a_dump_registers(struct sd *sd);
	static int s5k83a_get_rotation(struct sd sd, u8 reg_data);
	static int s5k83a_set_led_indication(struct sd *sd, u8 val);
	static int s5k83a_set_flip_real(struct gspca_dev *gspca_dev,
	__s32 vflip, __s32 hflip);

	int s5k83a_probe(struct sd *sd)
	{
	u8 prod_id = 0, ver_id = 0;
	int i, err = 0;
	struct gspca_dev gspca_dev = (struct gspca_dev )sd;

	if (force_sensor) {
	if (force_sensor == S5K83A_SENSOR) {
	pr_info("Forcing a %s sensor\n", s5k83a.name);
	goto sensor_found;
	}
	/* If we want to force another sensor, don't try to probe this
	* one */
	return -ENODEV;
	}

	PDEBUG(D_PROBE, "Probing for a s5k83a sensor");

	/* Preinit the sensor */
	for (i = 0; i < ARRAY_SIZE(preinit_s5k83a) && !err; i++) {
	u8 data[2] = {preinit_s5k83a[i][2], preinit_s5k83a[i][3]};
	if (preinit_s5k83a[i][0] == SENSOR)
	err = m5602_write_sensor(sd, preinit_s5k83a[i][1],
	data, 2);
	else
	err = m5602_write_bridge(sd, preinit_s5k83a[i][1],
	data[0]);
	}

	/* We don't know what register (if any) that contain the product id
	* Just pick the first addresses that seem to produce the same results
	* on multiple machines */
	if (m5602_read_sensor(sd, 0x00, &prod_id, 1))
	return -ENODEV;

	if (m5602_read_sensor(sd, 0x01, &ver_id, 1))
	return -ENODEV;

	if ((prod_id == 0xff) \|\| (ver_id == 0xff))
	return -ENODEV;
	else
	pr_info("Detected a s5k83a sensor\n");

	sensor_found:
	sd->gspca_dev.cam.cam_mode = s5k83a_modes;
	sd->gspca_dev.cam.nmodes = ARRAY_SIZE(s5k83a_modes);

	/* null the pointer! thread is't running now */
	sd->rotation_thread = NULL;

	return 0;
	}

	int s5k83a_init(struct sd *sd)
	{
	int i, err = 0;

	for (i = 0; i < ARRAY_SIZE(init_s5k83a) && !err; i++) {
	u8 data[2] = {0x00, 0x00};

	switch (init_s5k83a[i][0]) {
	case BRIDGE:
	err = m5602_write_bridge(sd,
	init_s5k83a[i][1],
	init_s5k83a[i][2]);
	break;

	case SENSOR:
	data[0] = init_s5k83a[i][2];
	err = m5602_write_sensor(sd,
	init_s5k83a[i][1], data, 1);
	break;

	case SENSOR_LONG:
	data[0] = init_s5k83a[i][2];
	data[1] = init_s5k83a[i][3];
	err = m5602_write_sensor(sd,
	init_s5k83a[i][1], data, 2);
	break;
	default:
	pr_info("Invalid stream command, exiting init\n");
	return -EINVAL;
	}
	}

	if (dump_sensor)
	s5k83a_dump_registers(sd);

	return err;
	}

	int s5k83a_init_controls(struct sd *sd)
	{
	struct v4l2_ctrl_handler *hdl = &sd->gspca_dev.ctrl_handler;

	sd->gspca_dev.vdev.ctrl_handler = hdl;
	v4l2_ctrl_handler_init(hdl, 6);

	v4l2_ctrl_new_std(hdl, &s5k83a_ctrl_ops, V4L2_CID_BRIGHTNESS,
	0, 255, 1, S5K83A_DEFAULT_BRIGHTNESS);

	v4l2_ctrl_new_std(hdl, &s5k83a_ctrl_ops, V4L2_CID_EXPOSURE,
	0, S5K83A_MAXIMUM_EXPOSURE, 1,
	S5K83A_DEFAULT_EXPOSURE);

	v4l2_ctrl_new_std(hdl, &s5k83a_ctrl_ops, V4L2_CID_GAIN,
	0, 255, 1, S5K83A_DEFAULT_GAIN);

	sd->hflip = v4l2_ctrl_new_std(hdl, &s5k83a_ctrl_ops, V4L2_CID_HFLIP,
	0, 1, 1, 0);
	sd->vflip = v4l2_ctrl_new_std(hdl, &s5k83a_ctrl_ops, V4L2_CID_VFLIP,
	0, 1, 1, 0);

	if (hdl->error) {
	pr_err("Could not initialize controls\n");
	return hdl->error;
	}

	v4l2_ctrl_cluster(2, &sd->hflip);

	return 0;
	}

	static int rotation_thread_function(void *data)
	{
	struct sd sd = (struct sd ) data;
	u8 reg, previous_rotation = 0;
	__s32 vflip, hflip;

	set_current_state(TASK_INTERRUPTIBLE);
	while (!schedule_timeout(msecs_to_jiffies(100))) {
	if (mutex_lock_interruptible(&sd->gspca_dev.usb_lock))
	break;

	s5k83a_get_rotation(sd, &reg);
	if (previous_rotation != reg) {
	previous_rotation = reg;
	pr_info("Camera was flipped\n");

	hflip = sd->hflip->val;
	vflip = sd->vflip->val;

	if (reg) {
	vflip = !vflip;
	hflip = !hflip;
	}
	s5k83a_set_flip_real((struct gspca_dev *) sd,
	vflip, hflip);
	}

	mutex_unlock(&sd->gspca_dev.usb_lock);
	set_current_state(TASK_INTERRUPTIBLE);
	}

	/* return to "front" flip */
	if (previous_rotation) {
	hflip = sd->hflip->val;
	vflip = sd->vflip->val;
	s5k83a_set_flip_real((struct gspca_dev *) sd, vflip, hflip);
	}

	sd->rotation_thread = NULL;
	return 0;
	}

	int s5k83a_start(struct sd *sd)
	{
	int i, err = 0;

	/* Create another thread, polling the GPIO ports of the camera to check
	if it got rotated. This is how the windows driver does it so we have
	to assume that there is no better way of accomplishing this */
	sd->rotation_thread = kthread_create(rotation_thread_function,
	sd, "rotation thread");
	if (IS_ERR(sd->rotation_thread)) {
	err = PTR_ERR(sd->rotation_thread);
	sd->rotation_thread = NULL;
	return err;
	}
	wake_up_process(sd->rotation_thread);

	/* Preinit the sensor */
	for (i = 0; i < ARRAY_SIZE(start_s5k83a) && !err; i++) {
	u8 data[2] = {start_s5k83a[i][2], start_s5k83a[i][3]};
	if (start_s5k83a[i][0] == SENSOR)
	err = m5602_write_sensor(sd, start_s5k83a[i][1],
	data, 2);
	else
	err = m5602_write_bridge(sd, start_s5k83a[i][1],
	data[0]);
	}
	if (err < 0)
	return err;

	return s5k83a_set_led_indication(sd, 1);
	}

	int s5k83a_stop(struct sd *sd)
	{
	if (sd->rotation_thread)
	kthread_stop(sd->rotation_thread);

	return s5k83a_set_led_indication(sd, 0);
	}

	void s5k83a_disconnect(struct sd *sd)
	{
	s5k83a_stop(sd);

	sd->sensor = NULL;
	}

	static int s5k83a_set_gain(struct gspca_dev *gspca_dev, __s32 val)
	{
	int err;
	u8 data[2];
	struct sd sd = (struct sd ) gspca_dev;

	data[0] = 0x00;
	data[1] = 0x20;
	err = m5602_write_sensor(sd, 0x14, data, 2);
	if (err < 0)
	return err;

	data[0] = 0x01;
	data[1] = 0x00;
	err = m5602_write_sensor(sd, 0x0d, data, 2);
	if (err < 0)
	return err;

	/* FIXME: This is not sane, we need to figure out the composition
	of these registers */
	data[0] = val >> 3; /* gain, high 5 bits */
	data[1] = val >> 1; /* gain, high 7 bits */
	err = m5602_write_sensor(sd, S5K83A_GAIN, data, 2);

	return err;
	}

	static int s5k83a_set_brightness(struct gspca_dev *gspca_dev, __s32 val)
	{
	int err;
	u8 data[1];
	struct sd sd = (struct sd ) gspca_dev;

	data[0] = val;
	err = m5602_write_sensor(sd, S5K83A_BRIGHTNESS, data, 1);
	return err;
	}

	static int s5k83a_set_exposure(struct gspca_dev *gspca_dev, __s32 val)
	{
	int err;
	u8 data[2];
	struct sd sd = (struct sd ) gspca_dev;

	data[0] = 0;
	data[1] = val;
	err = m5602_write_sensor(sd, S5K83A_EXPOSURE, data, 2);
	return err;
	}

	static int s5k83a_set_flip_real(struct gspca_dev *gspca_dev,
	__s32 vflip, __s32 hflip)
	{
	int err;
	u8 data[1];
	struct sd sd = (struct sd ) gspca_dev;

	data[0] = 0x05;
	err = m5602_write_sensor(sd, S5K83A_PAGE_MAP, data, 1);
	if (err < 0)
	return err;

	/* six bit is vflip, seven is hflip */
	data[0] = S5K83A_FLIP_MASK;
	data[0] = (vflip) ? data[0] \| 0x40 : data[0];
	data[0] = (hflip) ? data[0] \| 0x80 : data[0];

	err = m5602_write_sensor(sd, S5K83A_FLIP, data, 1);
	if (err < 0)
	return err;

	data[0] = (vflip) ? 0x0b : 0x0a;
	err = m5602_write_sensor(sd, S5K83A_VFLIP_TUNE, data, 1);
	if (err < 0)
	return err;

	data[0] = (hflip) ? 0x0a : 0x0b;
	err = m5602_write_sensor(sd, S5K83A_HFLIP_TUNE, data, 1);
	return err;
	}

	static int s5k83a_set_hvflip(struct gspca_dev *gspca_dev)
	{
	int err;
	u8 reg;
	struct sd sd = (struct sd ) gspca_dev;
	int hflip = sd->hflip->val;
	int vflip = sd->vflip->val;

	err = s5k83a_get_rotation(sd, &reg);
	if (err < 0)
	return err;
	if (reg) {
	hflip = !hflip;
	vflip = !vflip;
	}

	err = s5k83a_set_flip_real(gspca_dev, vflip, hflip);
	return err;
	}

	static int s5k83a_s_ctrl(struct v4l2_ctrl *ctrl)
	{
	struct gspca_dev *gspca_dev =
	container_of(ctrl->handler, struct gspca_dev, ctrl_handler);
	int err;

	if (!gspca_dev->streaming)
	return 0;

	switch (ctrl->id) {
	case V4L2_CID_BRIGHTNESS:
	err = s5k83a_set_brightness(gspca_dev, ctrl->val);
	break;
	case V4L2_CID_EXPOSURE:
	err = s5k83a_set_exposure(gspca_dev, ctrl->val);
	break;
	case V4L2_CID_GAIN:
	err = s5k83a_set_gain(gspca_dev, ctrl->val);
	break;
	case V4L2_CID_HFLIP:
	err = s5k83a_set_hvflip(gspca_dev);
	break;
	default:
	return -EINVAL;
	}

	return err;
	}

	static int s5k83a_set_led_indication(struct sd *sd, u8 val)
	{
	int err = 0;
	u8 data[1];

	err = m5602_read_bridge(sd, M5602_XB_GPIO_DAT, data);
	if (err < 0)
	return err;

	if (val)
	data[0] = data[0] \| S5K83A_GPIO_LED_MASK;
	else
	data[0] = data[0] & ~S5K83A_GPIO_LED_MASK;

	err = m5602_write_bridge(sd, M5602_XB_GPIO_DAT, data[0]);

	return err;
	}

	/* Get camera rotation on Acer notebooks */
	static int s5k83a_get_rotation(struct sd sd, u8 reg_data)
	{
	int err = m5602_read_bridge(sd, M5602_XB_GPIO_DAT, reg_data);
	reg_data = (reg_data & S5K83A_GPIO_ROTATION_MASK) ? 0 : 1;
	return err;
	}

	static void s5k83a_dump_registers(struct sd *sd)
	{
	int address;
	u8 page, old_page;
	m5602_read_sensor(sd, S5K83A_PAGE_MAP, &old_page, 1);

	for (page = 0; page < 16; page++) {
	m5602_write_sensor(sd, S5K83A_PAGE_MAP, &page, 1);
	pr_info("Dumping the s5k83a register state for page 0x%x\n",
	page);
	for (address = 0; address <= 0xff; address++) {
	u8 val = 0;
	m5602_read_sensor(sd, address, &val, 1);
	pr_info("register 0x%x contains 0x%x\n", address, val);
	}
	}
	pr_info("s5k83a register state dump complete\n");

	for (page = 0; page < 16; page++) {
	m5602_write_sensor(sd, S5K83A_PAGE_MAP, &page, 1);
	pr_info("Probing for which registers that are read/write for page 0x%x\n",
	page);
	for (address = 0; address <= 0xff; address++) {
	u8 old_val, ctrl_val, test_val = 0xff;

	m5602_read_sensor(sd, address, &old_val, 1);
	m5602_write_sensor(sd, address, &test_val, 1);
	m5602_read_sensor(sd, address, &ctrl_val, 1);

	if (ctrl_val == test_val)
	pr_info("register 0x%x is writeable\n",
	address);
	else
	pr_info("register 0x%x is read only\n",
	address);

	/* Restore original val */
	m5602_write_sensor(sd, address, &old_val, 1);
	}
	}
	pr_info("Read/write register probing complete\n");
	m5602_write_sensor(sd, S5K83A_PAGE_MAP, &old_page, 1);
	}