2 * Driver for the ov9650 sensor
4 * Copyright (C) 2008 Erik Andrén
5 * Copyright (C) 2007 Ilyes Gouta. Based on the m5603x Linux Driver Project.
6 * Copyright (C) 2005 m5603x Linux Driver Project <m5602@x3ng.com.br>
8 * Portions of code to USB interface and ALi driver software,
9 * Copyright (c) 2006 Willem Duinker
10 * v4l2 interface modeled after the V4L2 driver
11 * for SN9C10x PC Camera Controllers
13 * This program is free software; you can redistribute it and/or
14 * modify it under the terms of the GNU General Public License as
15 * published by the Free Software Foundation, version 2.
19 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
21 #include "m5602_ov9650.h"
23 static int ov9650_set_exposure(struct gspca_dev *gspca_dev, __s32 val);
24 static int ov9650_get_exposure(struct gspca_dev *gspca_dev, __s32 *val);
25 static int ov9650_get_gain(struct gspca_dev *gspca_dev, __s32 *val);
26 static int ov9650_set_gain(struct gspca_dev *gspca_dev, __s32 val);
27 static int ov9650_get_red_balance(struct gspca_dev *gspca_dev, __s32 *val);
28 static int ov9650_set_red_balance(struct gspca_dev *gspca_dev, __s32 val);
29 static int ov9650_get_blue_balance(struct gspca_dev *gspca_dev, __s32 *val);
30 static int ov9650_set_blue_balance(struct gspca_dev *gspca_dev, __s32 val);
31 static int ov9650_get_hflip(struct gspca_dev *gspca_dev, __s32 *val);
32 static int ov9650_set_hflip(struct gspca_dev *gspca_dev, __s32 val);
33 static int ov9650_get_vflip(struct gspca_dev *gspca_dev, __s32 *val);
34 static int ov9650_set_vflip(struct gspca_dev *gspca_dev, __s32 val);
35 static int ov9650_get_auto_white_balance(struct gspca_dev *gspca_dev,
37 static int ov9650_set_auto_white_balance(struct gspca_dev *gspca_dev,
39 static int ov9650_get_auto_gain(struct gspca_dev *gspca_dev, __s32 *val);
40 static int ov9650_set_auto_gain(struct gspca_dev *gspca_dev, __s32 val);
41 static int ov9650_get_auto_exposure(struct gspca_dev *gspca_dev, __s32 *val);
42 static int ov9650_set_auto_exposure(struct gspca_dev *gspca_dev, __s32 val);
44 /* Vertically and horizontally flips the image if matched, needed for machines
45 where the sensor is mounted upside down */
48 struct dmi_system_id ov9650_flip_dmi_table[] = {
52 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
53 DMI_MATCH(DMI_PRODUCT_NAME, "A6J")
59 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
60 DMI_MATCH(DMI_PRODUCT_NAME, "A6JC")
66 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
67 DMI_MATCH(DMI_PRODUCT_NAME, "A6K")
73 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
74 DMI_MATCH(DMI_PRODUCT_NAME, "A6Kt")
80 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
81 DMI_MATCH(DMI_PRODUCT_NAME, "A6VA")
88 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
89 DMI_MATCH(DMI_PRODUCT_NAME, "A6VC")
95 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
96 DMI_MATCH(DMI_PRODUCT_NAME, "A6VM")
102 DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK Computer Inc."),
103 DMI_MATCH(DMI_PRODUCT_NAME, "A7V")
107 .ident = "Alienware Aurora m9700",
109 DMI_MATCH(DMI_SYS_VENDOR, "alienware"),
110 DMI_MATCH(DMI_PRODUCT_NAME, "Aurora m9700")
116 static const struct ctrl ov9650_ctrls[] = {
117 #define EXPOSURE_IDX 0
120 .id = V4L2_CID_EXPOSURE,
121 .type = V4L2_CTRL_TYPE_INTEGER,
126 .default_value = EXPOSURE_DEFAULT,
127 .flags = V4L2_CTRL_FLAG_SLIDER
129 .set = ov9650_set_exposure,
130 .get = ov9650_get_exposure
136 .type = V4L2_CTRL_TYPE_INTEGER,
141 .default_value = GAIN_DEFAULT,
142 .flags = V4L2_CTRL_FLAG_SLIDER
144 .set = ov9650_set_gain,
145 .get = ov9650_get_gain
147 #define RED_BALANCE_IDX 2
150 .id = V4L2_CID_RED_BALANCE,
151 .type = V4L2_CTRL_TYPE_INTEGER,
152 .name = "red balance",
156 .default_value = RED_GAIN_DEFAULT,
157 .flags = V4L2_CTRL_FLAG_SLIDER
159 .set = ov9650_set_red_balance,
160 .get = ov9650_get_red_balance
162 #define BLUE_BALANCE_IDX 3
165 .id = V4L2_CID_BLUE_BALANCE,
166 .type = V4L2_CTRL_TYPE_INTEGER,
167 .name = "blue balance",
171 .default_value = BLUE_GAIN_DEFAULT,
172 .flags = V4L2_CTRL_FLAG_SLIDER
174 .set = ov9650_set_blue_balance,
175 .get = ov9650_get_blue_balance
180 .id = V4L2_CID_HFLIP,
181 .type = V4L2_CTRL_TYPE_BOOLEAN,
182 .name = "horizontal flip",
188 .set = ov9650_set_hflip,
189 .get = ov9650_get_hflip
194 .id = V4L2_CID_VFLIP,
195 .type = V4L2_CTRL_TYPE_BOOLEAN,
196 .name = "vertical flip",
202 .set = ov9650_set_vflip,
203 .get = ov9650_get_vflip
205 #define AUTO_WHITE_BALANCE_IDX 6
208 .id = V4L2_CID_AUTO_WHITE_BALANCE,
209 .type = V4L2_CTRL_TYPE_BOOLEAN,
210 .name = "auto white balance",
216 .set = ov9650_set_auto_white_balance,
217 .get = ov9650_get_auto_white_balance
219 #define AUTO_GAIN_CTRL_IDX 7
222 .id = V4L2_CID_AUTOGAIN,
223 .type = V4L2_CTRL_TYPE_BOOLEAN,
224 .name = "auto gain control",
230 .set = ov9650_set_auto_gain,
231 .get = ov9650_get_auto_gain
233 #define AUTO_EXPOSURE_IDX 8
236 .id = V4L2_CID_EXPOSURE_AUTO,
237 .type = V4L2_CTRL_TYPE_BOOLEAN,
238 .name = "auto exposure",
244 .set = ov9650_set_auto_exposure,
245 .get = ov9650_get_auto_exposure
250 static struct v4l2_pix_format ov9650_modes[] = {
259 .colorspace = V4L2_COLORSPACE_SRGB,
269 .colorspace = V4L2_COLORSPACE_SRGB,
279 .colorspace = V4L2_COLORSPACE_SRGB,
289 .colorspace = V4L2_COLORSPACE_SRGB,
294 static void ov9650_dump_registers(struct sd *sd);
296 int ov9650_probe(struct sd *sd)
299 u8 prod_id = 0, ver_id = 0, i;
300 s32 *sensor_settings;
303 if (force_sensor == OV9650_SENSOR) {
304 pr_info("Forcing an %s sensor\n", ov9650.name);
307 /* If we want to force another sensor,
308 don't try to probe this one */
312 PDEBUG(D_PROBE, "Probing for an ov9650 sensor");
314 /* Run the pre-init before probing the sensor */
315 for (i = 0; i < ARRAY_SIZE(preinit_ov9650) && !err; i++) {
316 u8 data = preinit_ov9650[i][2];
317 if (preinit_ov9650[i][0] == SENSOR)
318 err = m5602_write_sensor(sd,
319 preinit_ov9650[i][1], &data, 1);
321 err = m5602_write_bridge(sd,
322 preinit_ov9650[i][1], data);
328 if (m5602_read_sensor(sd, OV9650_PID, &prod_id, 1))
331 if (m5602_read_sensor(sd, OV9650_VER, &ver_id, 1))
334 if ((prod_id == 0x96) && (ver_id == 0x52)) {
335 pr_info("Detected an ov9650 sensor\n");
341 sensor_settings = kmalloc(
342 ARRAY_SIZE(ov9650_ctrls) * sizeof(s32), GFP_KERNEL);
343 if (!sensor_settings)
346 sd->gspca_dev.cam.cam_mode = ov9650_modes;
347 sd->gspca_dev.cam.nmodes = ARRAY_SIZE(ov9650_modes);
348 sd->desc->ctrls = ov9650_ctrls;
349 sd->desc->nctrls = ARRAY_SIZE(ov9650_ctrls);
351 for (i = 0; i < ARRAY_SIZE(ov9650_ctrls); i++)
352 sensor_settings[i] = ov9650_ctrls[i].qctrl.default_value;
353 sd->sensor_priv = sensor_settings;
357 int ov9650_init(struct sd *sd)
361 s32 *sensor_settings = sd->sensor_priv;
364 ov9650_dump_registers(sd);
366 for (i = 0; i < ARRAY_SIZE(init_ov9650) && !err; i++) {
367 data = init_ov9650[i][2];
368 if (init_ov9650[i][0] == SENSOR)
369 err = m5602_write_sensor(sd, init_ov9650[i][1],
372 err = m5602_write_bridge(sd, init_ov9650[i][1], data);
375 err = ov9650_set_exposure(&sd->gspca_dev,
376 sensor_settings[EXPOSURE_IDX]);
380 err = ov9650_set_gain(&sd->gspca_dev, sensor_settings[GAIN_IDX]);
384 err = ov9650_set_red_balance(&sd->gspca_dev,
385 sensor_settings[RED_BALANCE_IDX]);
389 err = ov9650_set_blue_balance(&sd->gspca_dev,
390 sensor_settings[BLUE_BALANCE_IDX]);
394 err = ov9650_set_hflip(&sd->gspca_dev, sensor_settings[HFLIP_IDX]);
398 err = ov9650_set_vflip(&sd->gspca_dev, sensor_settings[VFLIP_IDX]);
402 err = ov9650_set_auto_exposure(&sd->gspca_dev,
403 sensor_settings[AUTO_EXPOSURE_IDX]);
407 err = ov9650_set_auto_white_balance(&sd->gspca_dev,
408 sensor_settings[AUTO_WHITE_BALANCE_IDX]);
412 err = ov9650_set_auto_gain(&sd->gspca_dev,
413 sensor_settings[AUTO_GAIN_CTRL_IDX]);
417 int ov9650_start(struct sd *sd)
421 struct cam *cam = &sd->gspca_dev.cam;
422 s32 *sensor_settings = sd->sensor_priv;
424 int width = cam->cam_mode[sd->gspca_dev.curr_mode].width;
425 int height = cam->cam_mode[sd->gspca_dev.curr_mode].height;
426 int ver_offs = cam->cam_mode[sd->gspca_dev.curr_mode].priv;
427 int hor_offs = OV9650_LEFT_OFFSET;
429 if ((!dmi_check_system(ov9650_flip_dmi_table) &&
430 sensor_settings[VFLIP_IDX]) ||
431 (dmi_check_system(ov9650_flip_dmi_table) &&
432 !sensor_settings[VFLIP_IDX]))
438 /* Synthesize the vsync/hsync setup */
439 for (i = 0; i < ARRAY_SIZE(res_init_ov9650) && !err; i++) {
440 if (res_init_ov9650[i][0] == BRIDGE)
441 err = m5602_write_bridge(sd, res_init_ov9650[i][1],
442 res_init_ov9650[i][2]);
443 else if (res_init_ov9650[i][0] == SENSOR) {
444 data = res_init_ov9650[i][2];
445 err = m5602_write_sensor(sd,
446 res_init_ov9650[i][1], &data, 1);
452 err = m5602_write_bridge(sd, M5602_XB_VSYNC_PARA,
453 ((ver_offs >> 8) & 0xff));
457 err = m5602_write_bridge(sd, M5602_XB_VSYNC_PARA, (ver_offs & 0xff));
461 err = m5602_write_bridge(sd, M5602_XB_VSYNC_PARA, 0);
465 err = m5602_write_bridge(sd, M5602_XB_VSYNC_PARA, (height >> 8) & 0xff);
469 err = m5602_write_bridge(sd, M5602_XB_VSYNC_PARA, (height & 0xff));
473 for (i = 0; i < 2 && !err; i++)
474 err = m5602_write_bridge(sd, M5602_XB_VSYNC_PARA, 0);
478 err = m5602_write_bridge(sd, M5602_XB_SIG_INI, 0);
482 err = m5602_write_bridge(sd, M5602_XB_SIG_INI, 2);
486 err = m5602_write_bridge(sd, M5602_XB_HSYNC_PARA,
487 (hor_offs >> 8) & 0xff);
491 err = m5602_write_bridge(sd, M5602_XB_HSYNC_PARA, hor_offs & 0xff);
495 err = m5602_write_bridge(sd, M5602_XB_HSYNC_PARA,
496 ((width + hor_offs) >> 8) & 0xff);
500 err = m5602_write_bridge(sd, M5602_XB_HSYNC_PARA,
501 ((width + hor_offs) & 0xff));
505 err = m5602_write_bridge(sd, M5602_XB_SIG_INI, 0);
511 PDEBUG(D_V4L2, "Configuring camera for VGA mode");
513 data = OV9650_VGA_SELECT | OV9650_RGB_SELECT |
514 OV9650_RAW_RGB_SELECT;
515 err = m5602_write_sensor(sd, OV9650_COM7, &data, 1);
519 PDEBUG(D_V4L2, "Configuring camera for CIF mode");
521 data = OV9650_CIF_SELECT | OV9650_RGB_SELECT |
522 OV9650_RAW_RGB_SELECT;
523 err = m5602_write_sensor(sd, OV9650_COM7, &data, 1);
527 PDEBUG(D_V4L2, "Configuring camera for QVGA mode");
529 data = OV9650_QVGA_SELECT | OV9650_RGB_SELECT |
530 OV9650_RAW_RGB_SELECT;
531 err = m5602_write_sensor(sd, OV9650_COM7, &data, 1);
535 PDEBUG(D_V4L2, "Configuring camera for QCIF mode");
537 data = OV9650_QCIF_SELECT | OV9650_RGB_SELECT |
538 OV9650_RAW_RGB_SELECT;
539 err = m5602_write_sensor(sd, OV9650_COM7, &data, 1);
545 int ov9650_stop(struct sd *sd)
547 u8 data = OV9650_SOFT_SLEEP | OV9650_OUTPUT_DRIVE_2X;
548 return m5602_write_sensor(sd, OV9650_COM2, &data, 1);
551 void ov9650_disconnect(struct sd *sd)
556 kfree(sd->sensor_priv);
559 static int ov9650_get_exposure(struct gspca_dev *gspca_dev, __s32 *val)
561 struct sd *sd = (struct sd *) gspca_dev;
562 s32 *sensor_settings = sd->sensor_priv;
564 *val = sensor_settings[EXPOSURE_IDX];
565 PDEBUG(D_V4L2, "Read exposure %d", *val);
569 static int ov9650_set_exposure(struct gspca_dev *gspca_dev, __s32 val)
571 struct sd *sd = (struct sd *) gspca_dev;
572 s32 *sensor_settings = sd->sensor_priv;
576 PDEBUG(D_V4L2, "Set exposure to %d", val);
578 sensor_settings[EXPOSURE_IDX] = val;
580 i2c_data = (val >> 10) & 0x3f;
581 err = m5602_write_sensor(sd, OV9650_AECHM,
586 /* The 8 middle bits */
587 i2c_data = (val >> 2) & 0xff;
588 err = m5602_write_sensor(sd, OV9650_AECH,
594 i2c_data = val & 0x03;
595 err = m5602_write_sensor(sd, OV9650_COM1, &i2c_data, 1);
599 static int ov9650_get_gain(struct gspca_dev *gspca_dev, __s32 *val)
601 struct sd *sd = (struct sd *) gspca_dev;
602 s32 *sensor_settings = sd->sensor_priv;
604 *val = sensor_settings[GAIN_IDX];
605 PDEBUG(D_V4L2, "Read gain %d", *val);
609 static int ov9650_set_gain(struct gspca_dev *gspca_dev, __s32 val)
613 struct sd *sd = (struct sd *) gspca_dev;
614 s32 *sensor_settings = sd->sensor_priv;
616 PDEBUG(D_V4L2, "Setting gain to %d", val);
618 sensor_settings[GAIN_IDX] = val;
621 /* Read the OV9650_VREF register first to avoid
622 corrupting the VREF high and low bits */
623 err = m5602_read_sensor(sd, OV9650_VREF, &i2c_data, 1);
627 /* Mask away all uninteresting bits */
628 i2c_data = ((val & 0x0300) >> 2) |
630 err = m5602_write_sensor(sd, OV9650_VREF, &i2c_data, 1);
635 i2c_data = val & 0xff;
636 err = m5602_write_sensor(sd, OV9650_GAIN, &i2c_data, 1);
640 static int ov9650_get_red_balance(struct gspca_dev *gspca_dev, __s32 *val)
642 struct sd *sd = (struct sd *) gspca_dev;
643 s32 *sensor_settings = sd->sensor_priv;
645 *val = sensor_settings[RED_BALANCE_IDX];
646 PDEBUG(D_V4L2, "Read red gain %d", *val);
650 static int ov9650_set_red_balance(struct gspca_dev *gspca_dev, __s32 val)
654 struct sd *sd = (struct sd *) gspca_dev;
655 s32 *sensor_settings = sd->sensor_priv;
657 PDEBUG(D_V4L2, "Set red gain to %d", val);
659 sensor_settings[RED_BALANCE_IDX] = val;
661 i2c_data = val & 0xff;
662 err = m5602_write_sensor(sd, OV9650_RED, &i2c_data, 1);
666 static int ov9650_get_blue_balance(struct gspca_dev *gspca_dev, __s32 *val)
668 struct sd *sd = (struct sd *) gspca_dev;
669 s32 *sensor_settings = sd->sensor_priv;
671 *val = sensor_settings[BLUE_BALANCE_IDX];
672 PDEBUG(D_V4L2, "Read blue gain %d", *val);
677 static int ov9650_set_blue_balance(struct gspca_dev *gspca_dev, __s32 val)
681 struct sd *sd = (struct sd *) gspca_dev;
682 s32 *sensor_settings = sd->sensor_priv;
684 PDEBUG(D_V4L2, "Set blue gain to %d", val);
686 sensor_settings[BLUE_BALANCE_IDX] = val;
688 i2c_data = val & 0xff;
689 err = m5602_write_sensor(sd, OV9650_BLUE, &i2c_data, 1);
693 static int ov9650_get_hflip(struct gspca_dev *gspca_dev, __s32 *val)
695 struct sd *sd = (struct sd *) gspca_dev;
696 s32 *sensor_settings = sd->sensor_priv;
698 *val = sensor_settings[HFLIP_IDX];
699 PDEBUG(D_V4L2, "Read horizontal flip %d", *val);
703 static int ov9650_set_hflip(struct gspca_dev *gspca_dev, __s32 val)
707 struct sd *sd = (struct sd *) gspca_dev;
708 s32 *sensor_settings = sd->sensor_priv;
710 PDEBUG(D_V4L2, "Set horizontal flip to %d", val);
712 sensor_settings[HFLIP_IDX] = val;
714 if (!dmi_check_system(ov9650_flip_dmi_table))
715 i2c_data = ((val & 0x01) << 5) |
716 (sensor_settings[VFLIP_IDX] << 4);
718 i2c_data = ((val & 0x01) << 5) |
719 (!sensor_settings[VFLIP_IDX] << 4);
721 err = m5602_write_sensor(sd, OV9650_MVFP, &i2c_data, 1);
726 static int ov9650_get_vflip(struct gspca_dev *gspca_dev, __s32 *val)
728 struct sd *sd = (struct sd *) gspca_dev;
729 s32 *sensor_settings = sd->sensor_priv;
731 *val = sensor_settings[VFLIP_IDX];
732 PDEBUG(D_V4L2, "Read vertical flip %d", *val);
737 static int ov9650_set_vflip(struct gspca_dev *gspca_dev, __s32 val)
741 struct sd *sd = (struct sd *) gspca_dev;
742 s32 *sensor_settings = sd->sensor_priv;
744 PDEBUG(D_V4L2, "Set vertical flip to %d", val);
745 sensor_settings[VFLIP_IDX] = val;
747 if (dmi_check_system(ov9650_flip_dmi_table))
750 i2c_data = ((val & 0x01) << 4) | (sensor_settings[VFLIP_IDX] << 5);
751 err = m5602_write_sensor(sd, OV9650_MVFP, &i2c_data, 1);
755 /* When vflip is toggled we need to readjust the bridge hsync/vsync */
756 if (gspca_dev->streaming)
757 err = ov9650_start(sd);
762 static int ov9650_get_auto_exposure(struct gspca_dev *gspca_dev, __s32 *val)
764 struct sd *sd = (struct sd *) gspca_dev;
765 s32 *sensor_settings = sd->sensor_priv;
767 *val = sensor_settings[AUTO_EXPOSURE_IDX];
768 PDEBUG(D_V4L2, "Read auto exposure control %d", *val);
772 static int ov9650_set_auto_exposure(struct gspca_dev *gspca_dev,
777 struct sd *sd = (struct sd *) gspca_dev;
778 s32 *sensor_settings = sd->sensor_priv;
780 PDEBUG(D_V4L2, "Set auto exposure control to %d", val);
782 sensor_settings[AUTO_EXPOSURE_IDX] = val;
783 err = m5602_read_sensor(sd, OV9650_COM8, &i2c_data, 1);
787 i2c_data = ((i2c_data & 0xfe) | ((val & 0x01) << 0));
789 return m5602_write_sensor(sd, OV9650_COM8, &i2c_data, 1);
792 static int ov9650_get_auto_white_balance(struct gspca_dev *gspca_dev,
795 struct sd *sd = (struct sd *) gspca_dev;
796 s32 *sensor_settings = sd->sensor_priv;
798 *val = sensor_settings[AUTO_WHITE_BALANCE_IDX];
802 static int ov9650_set_auto_white_balance(struct gspca_dev *gspca_dev,
807 struct sd *sd = (struct sd *) gspca_dev;
808 s32 *sensor_settings = sd->sensor_priv;
810 PDEBUG(D_V4L2, "Set auto white balance to %d", val);
812 sensor_settings[AUTO_WHITE_BALANCE_IDX] = val;
813 err = m5602_read_sensor(sd, OV9650_COM8, &i2c_data, 1);
817 i2c_data = ((i2c_data & 0xfd) | ((val & 0x01) << 1));
818 err = m5602_write_sensor(sd, OV9650_COM8, &i2c_data, 1);
823 static int ov9650_get_auto_gain(struct gspca_dev *gspca_dev, __s32 *val)
825 struct sd *sd = (struct sd *) gspca_dev;
826 s32 *sensor_settings = sd->sensor_priv;
828 *val = sensor_settings[AUTO_GAIN_CTRL_IDX];
829 PDEBUG(D_V4L2, "Read auto gain control %d", *val);
833 static int ov9650_set_auto_gain(struct gspca_dev *gspca_dev, __s32 val)
837 struct sd *sd = (struct sd *) gspca_dev;
838 s32 *sensor_settings = sd->sensor_priv;
840 PDEBUG(D_V4L2, "Set auto gain control to %d", val);
842 sensor_settings[AUTO_GAIN_CTRL_IDX] = val;
843 err = m5602_read_sensor(sd, OV9650_COM8, &i2c_data, 1);
847 i2c_data = ((i2c_data & 0xfb) | ((val & 0x01) << 2));
849 return m5602_write_sensor(sd, OV9650_COM8, &i2c_data, 1);
852 static void ov9650_dump_registers(struct sd *sd)
855 pr_info("Dumping the ov9650 register state\n");
856 for (address = 0; address < 0xa9; address++) {
858 m5602_read_sensor(sd, address, &value, 1);
859 pr_info("register 0x%x contains 0x%x\n", address, value);
862 pr_info("ov9650 register state dump complete\n");
864 pr_info("Probing for which registers that are read/write\n");
865 for (address = 0; address < 0xff; address++) {
866 u8 old_value, ctrl_value;
867 u8 test_value[2] = {0xff, 0xff};
869 m5602_read_sensor(sd, address, &old_value, 1);
870 m5602_write_sensor(sd, address, test_value, 1);
871 m5602_read_sensor(sd, address, &ctrl_value, 1);
873 if (ctrl_value == test_value[0])
874 pr_info("register 0x%x is writeable\n", address);
876 pr_info("register 0x%x is read only\n", address);
878 /* Restore original value */
879 m5602_write_sensor(sd, address, &old_value, 1);