1 /*
2  * Support for GalaxyCore GC2235 2M camera sensor.
3  *
4  * Copyright (c) 2014 Intel Corporation. All Rights Reserved.
5  *
6  * This program is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU General Public License version
8  * 2 as published by the Free Software Foundation.
9  *
10  * This program is distributed in the hope that it will be useful,
11  * but WITHOUT ANY WARRANTY; without even the implied warranty of
12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
13  * GNU General Public License for more details.
14  *
15  */
16 
17 #include <linux/module.h>
18 #include <linux/types.h>
19 #include <linux/kernel.h>
20 #include <linux/mm.h>
21 #include <linux/string.h>
22 #include <linux/errno.h>
23 #include <linux/init.h>
24 #include <linux/kmod.h>
25 #include <linux/device.h>
26 #include <linux/delay.h>
27 #include <linux/slab.h>
28 #include <linux/i2c.h>
29 #include <linux/moduleparam.h>
30 #include <media/v4l2-device.h>
31 #include "../include/linux/atomisp_gmin_platform.h"
32 #include <linux/acpi.h>
33 #include <linux/io.h>
34 
35 #include "gc2235.h"
36 
37 /* i2c read/write stuff */
38 static int gc2235_read_reg(struct i2c_client *client,
39 			   u16 data_length, u16 reg, u16 *val)
40 {
41 	int err;
42 	struct i2c_msg msg[2];
43 	unsigned char data[6];
44 
45 	if (!client->adapter) {
46 		dev_err(&client->dev, "%s error, no client->adapter\n",
47 			__func__);
48 		return -ENODEV;
49 	}
50 
51 	if (data_length != GC2235_8BIT) {
52 		dev_err(&client->dev, "%s error, invalid data length\n",
53 			__func__);
54 		return -EINVAL;
55 	}
56 
57 	memset(msg, 0, sizeof(msg));
58 
59 	msg[0].addr = client->addr;
60 	msg[0].flags = 0;
61 	msg[0].len = 1;
62 	msg[0].buf = data;
63 
64 	/* high byte goes out first */
65 	data[0] = (u8)(reg & 0xff);
66 
67 	msg[1].addr = client->addr;
68 	msg[1].len = data_length;
69 	msg[1].flags = I2C_M_RD;
70 	msg[1].buf = data;
71 
72 	err = i2c_transfer(client->adapter, msg, 2);
73 	if (err != 2) {
74 		if (err >= 0)
75 			err = -EIO;
76 		dev_err(&client->dev,
77 			"read from offset 0x%x error %d", reg, err);
78 		return err;
79 	}
80 
81 	*val = 0;
82 	/* high byte comes first */
83 	if (data_length == GC2235_8BIT)
84 		*val = (u8)data[0];
85 
86 	return 0;
87 }
88 
89 static int gc2235_i2c_write(struct i2c_client *client, u16 len, u8 *data)
90 {
91 	struct i2c_msg msg;
92 	const int num_msg = 1;
93 	int ret;
94 
95 	msg.addr = client->addr;
96 	msg.flags = 0;
97 	msg.len = len;
98 	msg.buf = data;
99 	ret = i2c_transfer(client->adapter, &msg, 1);
100 
101 	return ret == num_msg ? 0 : -EIO;
102 }
103 
104 static int gc2235_write_reg(struct i2c_client *client, u16 data_length,
105 			    u8 reg, u8 val)
106 {
107 	int ret;
108 	unsigned char data[4] = {0};
109 	const u16 len = data_length + sizeof(u8); /* 16-bit address + data */
110 
111 	if (data_length != GC2235_8BIT) {
112 		dev_err(&client->dev,
113 			"%s error, invalid data_length\n", __func__);
114 		return -EINVAL;
115 	}
116 
117 	/* high byte goes out first */
118 	data[0] = reg;
119 	data[1] = val;
120 
121 	ret = gc2235_i2c_write(client, len, data);
122 	if (ret)
123 		dev_err(&client->dev,
124 			"write error: wrote 0x%x to offset 0x%x error %d",
125 			val, reg, ret);
126 
127 	return ret;
128 }
129 
130 static int __gc2235_flush_reg_array(struct i2c_client *client,
131 				    struct gc2235_write_ctrl *ctrl)
132 {
133 	u16 size;
134 
135 	if (ctrl->index == 0)
136 		return 0;
137 
138 	size = sizeof(u8) + ctrl->index; /* 8-bit address + data */
139 	ctrl->index = 0;
140 
141 	return gc2235_i2c_write(client, size, (u8 *)&ctrl->buffer);
142 }
143 
144 static int __gc2235_buf_reg_array(struct i2c_client *client,
145 				  struct gc2235_write_ctrl *ctrl,
146 				  const struct gc2235_reg *next)
147 {
148 	int size;
149 
150 	if (next->type != GC2235_8BIT)
151 		return -EINVAL;
152 
153 	size = 1;
154 	ctrl->buffer.data[ctrl->index] = (u8)next->val;
155 
156 	/* When first item is added, we need to store its starting address */
157 	if (ctrl->index == 0)
158 		ctrl->buffer.addr = next->reg;
159 
160 	ctrl->index += size;
161 
162 	/*
163 	 * Buffer cannot guarantee free space for u32? Better flush it to avoid
164 	 * possible lack of memory for next item.
165 	 */
166 	if (ctrl->index + sizeof(u8) >= GC2235_MAX_WRITE_BUF_SIZE)
167 		return __gc2235_flush_reg_array(client, ctrl);
168 
169 	return 0;
170 }
171 
172 static int __gc2235_write_reg_is_consecutive(struct i2c_client *client,
173 	struct gc2235_write_ctrl *ctrl,
174 	const struct gc2235_reg *next)
175 {
176 	if (ctrl->index == 0)
177 		return 1;
178 
179 	return ctrl->buffer.addr + ctrl->index == next->reg;
180 }
181 
182 static int gc2235_write_reg_array(struct i2c_client *client,
183 				  const struct gc2235_reg *reglist)
184 {
185 	const struct gc2235_reg *next = reglist;
186 	struct gc2235_write_ctrl ctrl;
187 	int err;
188 
189 	ctrl.index = 0;
190 	for (; next->type != GC2235_TOK_TERM; next++) {
191 		switch (next->type & GC2235_TOK_MASK) {
192 		case GC2235_TOK_DELAY:
193 			err = __gc2235_flush_reg_array(client, &ctrl);
194 			if (err)
195 				return err;
196 			msleep(next->val);
197 			break;
198 		default:
199 			/*
200 			 * If next address is not consecutive, data needs to be
201 			 * flushed before proceed.
202 			 */
203 			if (!__gc2235_write_reg_is_consecutive(client, &ctrl,
204 							       next)) {
205 				err = __gc2235_flush_reg_array(client, &ctrl);
206 				if (err)
207 					return err;
208 			}
209 			err = __gc2235_buf_reg_array(client, &ctrl, next);
210 			if (err) {
211 				dev_err(&client->dev, "%s: write error, aborted\n",
212 					__func__);
213 				return err;
214 			}
215 			break;
216 		}
217 	}
218 
219 	return __gc2235_flush_reg_array(client, &ctrl);
220 }
221 
222 static int gc2235_g_focal(struct v4l2_subdev *sd, s32 *val)
223 {
224 	*val = (GC2235_FOCAL_LENGTH_NUM << 16) | GC2235_FOCAL_LENGTH_DEM;
225 	return 0;
226 }
227 
228 static int gc2235_g_fnumber(struct v4l2_subdev *sd, s32 *val)
229 {
230 	/*const f number for imx*/
231 	*val = (GC2235_F_NUMBER_DEFAULT_NUM << 16) | GC2235_F_NUMBER_DEM;
232 	return 0;
233 }
234 
235 static int gc2235_g_fnumber_range(struct v4l2_subdev *sd, s32 *val)
236 {
237 	*val = (GC2235_F_NUMBER_DEFAULT_NUM << 24) |
238 	       (GC2235_F_NUMBER_DEM << 16) |
239 	       (GC2235_F_NUMBER_DEFAULT_NUM << 8) | GC2235_F_NUMBER_DEM;
240 	return 0;
241 }
242 
243 static int gc2235_get_intg_factor(struct i2c_client *client,
244 				  struct camera_mipi_info *info,
245 				  const struct gc2235_resolution *res)
246 {
247 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
248 	struct gc2235_device *dev = to_gc2235_sensor(sd);
249 	struct atomisp_sensor_mode_data *buf = &info->data;
250 	u16 reg_val, reg_val_h;
251 	int ret;
252 
253 	if (!info)
254 		return -EINVAL;
255 
256 	/* pixel clock calculattion */
257 	buf->vt_pix_clk_freq_mhz = dev->vt_pix_clk_freq_mhz = 30000000;
258 
259 	/* get integration time */
260 	buf->coarse_integration_time_min = GC2235_COARSE_INTG_TIME_MIN;
261 	buf->coarse_integration_time_max_margin =
262 	    GC2235_COARSE_INTG_TIME_MAX_MARGIN;
263 
264 	buf->fine_integration_time_min = GC2235_FINE_INTG_TIME_MIN;
265 	buf->fine_integration_time_max_margin =
266 	    GC2235_FINE_INTG_TIME_MAX_MARGIN;
267 
268 	buf->fine_integration_time_def = GC2235_FINE_INTG_TIME_MIN;
269 	buf->frame_length_lines = res->lines_per_frame;
270 	buf->line_length_pck = res->pixels_per_line;
271 	buf->read_mode = res->bin_mode;
272 
273 	/* get the cropping and output resolution to ISP for this mode. */
274 	ret =  gc2235_read_reg(client, GC2235_8BIT,
275 			       GC2235_H_CROP_START_H, &reg_val_h);
276 	ret =  gc2235_read_reg(client, GC2235_8BIT,
277 			       GC2235_H_CROP_START_L, &reg_val);
278 	if (ret)
279 		return ret;
280 
281 	buf->crop_horizontal_start = (reg_val_h << 8) | reg_val;
282 
283 	ret =  gc2235_read_reg(client, GC2235_8BIT,
284 			       GC2235_V_CROP_START_H, &reg_val_h);
285 	ret =  gc2235_read_reg(client, GC2235_8BIT,
286 			       GC2235_V_CROP_START_L, &reg_val);
287 	if (ret)
288 		return ret;
289 
290 	buf->crop_vertical_start = (reg_val_h << 8) | reg_val;
291 
292 	ret = gc2235_read_reg(client, GC2235_8BIT,
293 			      GC2235_H_OUTSIZE_H, &reg_val_h);
294 	ret = gc2235_read_reg(client, GC2235_8BIT,
295 			      GC2235_H_OUTSIZE_L, &reg_val);
296 	if (ret)
297 		return ret;
298 	buf->output_width = (reg_val_h << 8) | reg_val;
299 
300 	ret = gc2235_read_reg(client, GC2235_8BIT,
301 			      GC2235_V_OUTSIZE_H, &reg_val_h);
302 	ret = gc2235_read_reg(client, GC2235_8BIT,
303 			      GC2235_V_OUTSIZE_L, &reg_val);
304 	if (ret)
305 		return ret;
306 	buf->output_height = (reg_val_h << 8) | reg_val;
307 
308 	buf->crop_horizontal_end = buf->crop_horizontal_start +
309 				   buf->output_width - 1;
310 	buf->crop_vertical_end = buf->crop_vertical_start +
311 				 buf->output_height - 1;
312 
313 	ret = gc2235_read_reg(client, GC2235_8BIT,
314 			      GC2235_HB_H, &reg_val_h);
315 	ret = gc2235_read_reg(client, GC2235_8BIT,
316 			      GC2235_HB_L, &reg_val);
317 	if (ret)
318 		return ret;
319 
320 #if 0
321 	u16 dummy = (reg_val_h << 8) | reg_val;
322 #endif
323 
324 	ret = gc2235_read_reg(client, GC2235_8BIT,
325 			      GC2235_SH_DELAY_H, &reg_val_h);
326 	ret = gc2235_read_reg(client, GC2235_8BIT,
327 			      GC2235_SH_DELAY_L, &reg_val);
328 
329 #if 0
330 	buf->line_length_pck = buf->output_width + 16 + dummy +
331 			       (((u16)reg_val_h << 8) | (u16)reg_val) + 4;
332 #endif
333 	ret = gc2235_read_reg(client, GC2235_8BIT,
334 			      GC2235_VB_H, &reg_val_h);
335 	ret = gc2235_read_reg(client, GC2235_8BIT,
336 			      GC2235_VB_L, &reg_val);
337 	if (ret)
338 		return ret;
339 
340 #if 0
341 	buf->frame_length_lines = buf->output_height + 32 +
342 				  (((u16)reg_val_h << 8) | (u16)reg_val);
343 #endif
344 	buf->binning_factor_x = res->bin_factor_x ?
345 				res->bin_factor_x : 1;
346 	buf->binning_factor_y = res->bin_factor_y ?
347 				res->bin_factor_y : 1;
348 	return 0;
349 }
350 
351 static long __gc2235_set_exposure(struct v4l2_subdev *sd, int coarse_itg,
352 				  int gain, int digitgain)
353 
354 {
355 	struct i2c_client *client = v4l2_get_subdevdata(sd);
356 	u16 coarse_integration = (u16)coarse_itg;
357 	int ret = 0;
358 	u16 expo_coarse_h, expo_coarse_l, gain_val = 0xF0, gain_val2 = 0xF0;
359 
360 	expo_coarse_h = coarse_integration >> 8;
361 	expo_coarse_l = coarse_integration & 0xff;
362 
363 	ret = gc2235_write_reg(client, GC2235_8BIT,
364 			       GC2235_EXPOSURE_H, expo_coarse_h);
365 	ret = gc2235_write_reg(client, GC2235_8BIT,
366 			       GC2235_EXPOSURE_L, expo_coarse_l);
367 
368 	if (gain <= 0x58) {
369 		gain_val = 0x40;
370 		gain_val2 = 0x58;
371 	} else if (gain < 256) {
372 		gain_val = 0x40;
373 		gain_val2 = gain;
374 	} else {
375 		gain_val2 = 64 * gain / 256;
376 		gain_val = 0xff;
377 	}
378 
379 	ret = gc2235_write_reg(client, GC2235_8BIT,
380 			       GC2235_GLOBAL_GAIN, (u8)gain_val);
381 	ret = gc2235_write_reg(client, GC2235_8BIT,
382 			       GC2235_PRE_GAIN, (u8)gain_val2);
383 
384 	return ret;
385 }
386 
387 static int gc2235_set_exposure(struct v4l2_subdev *sd, int exposure,
388 			       int gain, int digitgain)
389 {
390 	struct gc2235_device *dev = to_gc2235_sensor(sd);
391 	int ret;
392 
393 	mutex_lock(&dev->input_lock);
394 	ret = __gc2235_set_exposure(sd, exposure, gain, digitgain);
395 	mutex_unlock(&dev->input_lock);
396 
397 	return ret;
398 }
399 
400 static long gc2235_s_exposure(struct v4l2_subdev *sd,
401 			      struct atomisp_exposure *exposure)
402 {
403 	int exp = exposure->integration_time[0];
404 	int gain = exposure->gain[0];
405 	int digitgain = exposure->gain[1];
406 
407 	/* we should not accept the invalid value below. */
408 	if (gain == 0) {
409 		struct i2c_client *client = v4l2_get_subdevdata(sd);
410 
411 		v4l2_err(client, "%s: invalid value\n", __func__);
412 		return -EINVAL;
413 	}
414 
415 	return gc2235_set_exposure(sd, exp, gain, digitgain);
416 }
417 
418 static long gc2235_ioctl(struct v4l2_subdev *sd, unsigned int cmd, void *arg)
419 {
420 	switch (cmd) {
421 	case ATOMISP_IOC_S_EXPOSURE:
422 		return gc2235_s_exposure(sd, arg);
423 	default:
424 		return -EINVAL;
425 	}
426 	return 0;
427 }
428 
429 /* This returns the exposure time being used. This should only be used
430  * for filling in EXIF data, not for actual image processing.
431  */
432 static int gc2235_q_exposure(struct v4l2_subdev *sd, s32 *value)
433 {
434 	struct i2c_client *client = v4l2_get_subdevdata(sd);
435 	u16 reg_v, reg_v2;
436 	int ret;
437 
438 	/* get exposure */
439 	ret = gc2235_read_reg(client, GC2235_8BIT,
440 			      GC2235_EXPOSURE_L,
441 			      &reg_v);
442 	if (ret)
443 		goto err;
444 
445 	ret = gc2235_read_reg(client, GC2235_8BIT,
446 			      GC2235_EXPOSURE_H,
447 			      &reg_v2);
448 	if (ret)
449 		goto err;
450 
451 	reg_v += reg_v2 << 8;
452 
453 	*value = reg_v;
454 err:
455 	return ret;
456 }
457 
458 static int gc2235_g_volatile_ctrl(struct v4l2_ctrl *ctrl)
459 {
460 	struct gc2235_device *dev =
461 	    container_of(ctrl->handler, struct gc2235_device, ctrl_handler);
462 	int ret = 0;
463 
464 	switch (ctrl->id) {
465 	case V4L2_CID_EXPOSURE_ABSOLUTE:
466 		ret = gc2235_q_exposure(&dev->sd, &ctrl->val);
467 		break;
468 	case V4L2_CID_FOCAL_ABSOLUTE:
469 		ret = gc2235_g_focal(&dev->sd, &ctrl->val);
470 		break;
471 	case V4L2_CID_FNUMBER_ABSOLUTE:
472 		ret = gc2235_g_fnumber(&dev->sd, &ctrl->val);
473 		break;
474 	case V4L2_CID_FNUMBER_RANGE:
475 		ret = gc2235_g_fnumber_range(&dev->sd, &ctrl->val);
476 		break;
477 	default:
478 		ret = -EINVAL;
479 	}
480 
481 	return ret;
482 }
483 
484 static const struct v4l2_ctrl_ops ctrl_ops = {
485 	.g_volatile_ctrl = gc2235_g_volatile_ctrl
486 };
487 
488 static struct v4l2_ctrl_config gc2235_controls[] = {
489 	{
490 		.ops = &ctrl_ops,
491 		.id = V4L2_CID_EXPOSURE_ABSOLUTE,
492 		.type = V4L2_CTRL_TYPE_INTEGER,
493 		.name = "exposure",
494 		.min = 0x0,
495 		.max = 0xffff,
496 		.step = 0x01,
497 		.def = 0x00,
498 		.flags = 0,
499 	},
500 	{
501 		.ops = &ctrl_ops,
502 		.id = V4L2_CID_FOCAL_ABSOLUTE,
503 		.type = V4L2_CTRL_TYPE_INTEGER,
504 		.name = "focal length",
505 		.min = GC2235_FOCAL_LENGTH_DEFAULT,
506 		.max = GC2235_FOCAL_LENGTH_DEFAULT,
507 		.step = 0x01,
508 		.def = GC2235_FOCAL_LENGTH_DEFAULT,
509 		.flags = 0,
510 	},
511 	{
512 		.ops = &ctrl_ops,
513 		.id = V4L2_CID_FNUMBER_ABSOLUTE,
514 		.type = V4L2_CTRL_TYPE_INTEGER,
515 		.name = "f-number",
516 		.min = GC2235_F_NUMBER_DEFAULT,
517 		.max = GC2235_F_NUMBER_DEFAULT,
518 		.step = 0x01,
519 		.def = GC2235_F_NUMBER_DEFAULT,
520 		.flags = 0,
521 	},
522 	{
523 		.ops = &ctrl_ops,
524 		.id = V4L2_CID_FNUMBER_RANGE,
525 		.type = V4L2_CTRL_TYPE_INTEGER,
526 		.name = "f-number range",
527 		.min = GC2235_F_NUMBER_RANGE,
528 		.max = GC2235_F_NUMBER_RANGE,
529 		.step = 0x01,
530 		.def = GC2235_F_NUMBER_RANGE,
531 		.flags = 0,
532 	},
533 };
534 
535 static int __gc2235_init(struct v4l2_subdev *sd)
536 {
537 	struct i2c_client *client = v4l2_get_subdevdata(sd);
538 
539 	/* restore settings */
540 	gc2235_res = gc2235_res_preview;
541 	N_RES = N_RES_PREVIEW;
542 
543 	return gc2235_write_reg_array(client, gc2235_init_settings);
544 }
545 
546 static int is_init;
547 
548 static int power_ctrl(struct v4l2_subdev *sd, bool flag)
549 {
550 	int ret = -1;
551 	struct gc2235_device *dev = to_gc2235_sensor(sd);
552 
553 	if (!dev || !dev->platform_data)
554 		return -ENODEV;
555 
556 	if (flag) {
557 		ret = dev->platform_data->v1p8_ctrl(sd, 1);
558 		usleep_range(60, 90);
559 		if (ret == 0)
560 			ret |= dev->platform_data->v2p8_ctrl(sd, 1);
561 	} else {
562 		ret = dev->platform_data->v1p8_ctrl(sd, 0);
563 		ret |= dev->platform_data->v2p8_ctrl(sd, 0);
564 	}
565 	return ret;
566 }
567 
568 static int gpio_ctrl(struct v4l2_subdev *sd, bool flag)
569 {
570 	struct gc2235_device *dev = to_gc2235_sensor(sd);
571 	int ret = -1;
572 
573 	if (!dev || !dev->platform_data)
574 		return -ENODEV;
575 
576 	ret |= dev->platform_data->gpio1_ctrl(sd, !flag);
577 	usleep_range(60, 90);
578 	return dev->platform_data->gpio0_ctrl(sd, flag);
579 }
580 
581 static int power_up(struct v4l2_subdev *sd)
582 {
583 	struct gc2235_device *dev = to_gc2235_sensor(sd);
584 	struct i2c_client *client = v4l2_get_subdevdata(sd);
585 	int ret;
586 
587 	if (!dev->platform_data) {
588 		dev_err(&client->dev,
589 			"no camera_sensor_platform_data");
590 		return -ENODEV;
591 	}
592 	/* power control */
593 	ret = power_ctrl(sd, 1);
594 	if (ret)
595 		goto fail_power;
596 
597 	/* according to DS, at least 5ms is needed between DOVDD and PWDN */
598 	usleep_range(5000, 6000);
599 
600 	ret = dev->platform_data->flisclk_ctrl(sd, 1);
601 	if (ret)
602 		goto fail_clk;
603 	usleep_range(5000, 6000);
604 
605 	/* gpio ctrl */
606 	ret = gpio_ctrl(sd, 1);
607 	if (ret) {
608 		ret = gpio_ctrl(sd, 1);
609 		if (ret)
610 			goto fail_power;
611 	}
612 
613 	msleep(5);
614 	return 0;
615 
616 fail_clk:
617 	gpio_ctrl(sd, 0);
618 fail_power:
619 	power_ctrl(sd, 0);
620 	dev_err(&client->dev, "sensor power-up failed\n");
621 
622 	return ret;
623 }
624 
625 static int power_down(struct v4l2_subdev *sd)
626 {
627 	struct gc2235_device *dev = to_gc2235_sensor(sd);
628 	struct i2c_client *client = v4l2_get_subdevdata(sd);
629 	int ret = 0;
630 
631 	if (!dev->platform_data) {
632 		dev_err(&client->dev,
633 			"no camera_sensor_platform_data");
634 		return -ENODEV;
635 	}
636 	/* gpio ctrl */
637 	ret = gpio_ctrl(sd, 0);
638 	if (ret) {
639 		ret = gpio_ctrl(sd, 0);
640 		if (ret)
641 			dev_err(&client->dev, "gpio failed 2\n");
642 	}
643 
644 	ret = dev->platform_data->flisclk_ctrl(sd, 0);
645 	if (ret)
646 		dev_err(&client->dev, "flisclk failed\n");
647 
648 	/* power control */
649 	ret = power_ctrl(sd, 0);
650 	if (ret)
651 		dev_err(&client->dev, "vprog failed.\n");
652 
653 	return ret;
654 }
655 
656 static int gc2235_s_power(struct v4l2_subdev *sd, int on)
657 {
658 	int ret;
659 
660 	if (on == 0)
661 		ret = power_down(sd);
662 	else {
663 		ret = power_up(sd);
664 		if (!ret)
665 			ret = __gc2235_init(sd);
666 		is_init = 1;
667 	}
668 	return ret;
669 }
670 
671 /*
672  * distance - calculate the distance
673  * @res: resolution
674  * @w: width
675  * @h: height
676  *
677  * Get the gap between resolution and w/h.
678  * res->width/height smaller than w/h wouldn't be considered.
679  * Returns the value of gap or -1 if fail.
680  */
681 #define LARGEST_ALLOWED_RATIO_MISMATCH 800
682 static int distance(struct gc2235_resolution *res, u32 w, u32 h)
683 {
684 	unsigned int w_ratio = (res->width << 13) / w;
685 	unsigned int h_ratio;
686 	int match;
687 
688 	if (h == 0)
689 		return -1;
690 	h_ratio = (res->height << 13) / h;
691 	if (h_ratio == 0)
692 		return -1;
693 	match   = abs(((w_ratio << 13) / h_ratio) - 8192);
694 
695 	if ((w_ratio < 8192) || (h_ratio < 8192) ||
696 	    (match > LARGEST_ALLOWED_RATIO_MISMATCH))
697 		return -1;
698 
699 	return w_ratio + h_ratio;
700 }
701 
702 /* Return the nearest higher resolution index */
703 static int nearest_resolution_index(int w, int h)
704 {
705 	int i;
706 	int idx = -1;
707 	int dist;
708 	int min_dist = INT_MAX;
709 	struct gc2235_resolution *tmp_res = NULL;
710 
711 	for (i = 0; i < N_RES; i++) {
712 		tmp_res = &gc2235_res[i];
713 		dist = distance(tmp_res, w, h);
714 		if (dist == -1)
715 			continue;
716 		if (dist < min_dist) {
717 			min_dist = dist;
718 			idx = i;
719 		}
720 	}
721 
722 	return idx;
723 }
724 
725 static int get_resolution_index(int w, int h)
726 {
727 	int i;
728 
729 	for (i = 0; i < N_RES; i++) {
730 		if (w != gc2235_res[i].width)
731 			continue;
732 		if (h != gc2235_res[i].height)
733 			continue;
734 
735 		return i;
736 	}
737 
738 	return -1;
739 }
740 
741 static int startup(struct v4l2_subdev *sd)
742 {
743 	struct gc2235_device *dev = to_gc2235_sensor(sd);
744 	struct i2c_client *client = v4l2_get_subdevdata(sd);
745 	int ret = 0;
746 
747 	if (is_init == 0) {
748 		/* force gc2235 to do a reset in res change, otherwise it
749 		* can not output normal after switching res. and it is not
750 		* necessary for first time run up after power on, for the sack
751 		* of performance
752 		*/
753 		power_down(sd);
754 		power_up(sd);
755 		gc2235_write_reg_array(client, gc2235_init_settings);
756 	}
757 
758 	ret = gc2235_write_reg_array(client, gc2235_res[dev->fmt_idx].regs);
759 	if (ret) {
760 		dev_err(&client->dev, "gc2235 write register err.\n");
761 		return ret;
762 	}
763 	is_init = 0;
764 
765 	return ret;
766 }
767 
768 static int gc2235_set_fmt(struct v4l2_subdev *sd,
769 			  struct v4l2_subdev_pad_config *cfg,
770 			  struct v4l2_subdev_format *format)
771 {
772 	struct v4l2_mbus_framefmt *fmt = &format->format;
773 	struct gc2235_device *dev = to_gc2235_sensor(sd);
774 	struct i2c_client *client = v4l2_get_subdevdata(sd);
775 	struct camera_mipi_info *gc2235_info = NULL;
776 	int ret = 0;
777 	int idx;
778 
779 	gc2235_info = v4l2_get_subdev_hostdata(sd);
780 	if (!gc2235_info)
781 		return -EINVAL;
782 	if (format->pad)
783 		return -EINVAL;
784 	if (!fmt)
785 		return -EINVAL;
786 	mutex_lock(&dev->input_lock);
787 	idx = nearest_resolution_index(fmt->width, fmt->height);
788 	if (idx == -1) {
789 		/* return the largest resolution */
790 		fmt->width = gc2235_res[N_RES - 1].width;
791 		fmt->height = gc2235_res[N_RES - 1].height;
792 	} else {
793 		fmt->width = gc2235_res[idx].width;
794 		fmt->height = gc2235_res[idx].height;
795 	}
796 	fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10;
797 	if (format->which == V4L2_SUBDEV_FORMAT_TRY) {
798 		cfg->try_fmt = *fmt;
799 		mutex_unlock(&dev->input_lock);
800 		return 0;
801 	}
802 
803 	dev->fmt_idx = get_resolution_index(fmt->width, fmt->height);
804 	if (dev->fmt_idx == -1) {
805 		dev_err(&client->dev, "get resolution fail\n");
806 		mutex_unlock(&dev->input_lock);
807 		return -EINVAL;
808 	}
809 
810 	ret = startup(sd);
811 	if (ret) {
812 		dev_err(&client->dev, "gc2235 startup err\n");
813 		goto err;
814 	}
815 
816 	ret = gc2235_get_intg_factor(client, gc2235_info,
817 				     &gc2235_res[dev->fmt_idx]);
818 	if (ret)
819 		dev_err(&client->dev, "failed to get integration_factor\n");
820 
821 err:
822 	mutex_unlock(&dev->input_lock);
823 	return ret;
824 }
825 
826 static int gc2235_get_fmt(struct v4l2_subdev *sd,
827 			  struct v4l2_subdev_pad_config *cfg,
828 			  struct v4l2_subdev_format *format)
829 {
830 	struct v4l2_mbus_framefmt *fmt = &format->format;
831 	struct gc2235_device *dev = to_gc2235_sensor(sd);
832 
833 	if (format->pad)
834 		return -EINVAL;
835 
836 	if (!fmt)
837 		return -EINVAL;
838 
839 	fmt->width = gc2235_res[dev->fmt_idx].width;
840 	fmt->height = gc2235_res[dev->fmt_idx].height;
841 	fmt->code = MEDIA_BUS_FMT_SGRBG10_1X10;
842 
843 	return 0;
844 }
845 
846 static int gc2235_detect(struct i2c_client *client)
847 {
848 	struct i2c_adapter *adapter = client->adapter;
849 	u16 high, low;
850 	int ret;
851 	u16 id;
852 
853 	if (!i2c_check_functionality(adapter, I2C_FUNC_I2C))
854 		return -ENODEV;
855 
856 	ret = gc2235_read_reg(client, GC2235_8BIT,
857 			      GC2235_SENSOR_ID_H, &high);
858 	if (ret) {
859 		dev_err(&client->dev, "sensor_id_high = 0x%x\n", high);
860 		return -ENODEV;
861 	}
862 	ret = gc2235_read_reg(client, GC2235_8BIT,
863 			      GC2235_SENSOR_ID_L, &low);
864 	id = ((high << 8) | low);
865 
866 	if (id != GC2235_ID) {
867 		dev_err(&client->dev, "sensor ID error, 0x%x\n", id);
868 		return -ENODEV;
869 	}
870 
871 	dev_info(&client->dev, "detect gc2235 success\n");
872 	return 0;
873 }
874 
875 static int gc2235_s_stream(struct v4l2_subdev *sd, int enable)
876 {
877 	struct gc2235_device *dev = to_gc2235_sensor(sd);
878 	struct i2c_client *client = v4l2_get_subdevdata(sd);
879 	int ret;
880 
881 	mutex_lock(&dev->input_lock);
882 
883 	if (enable)
884 		ret = gc2235_write_reg_array(client, gc2235_stream_on);
885 	else
886 		ret = gc2235_write_reg_array(client, gc2235_stream_off);
887 
888 	mutex_unlock(&dev->input_lock);
889 	return ret;
890 }
891 
892 static int gc2235_s_config(struct v4l2_subdev *sd,
893 			   int irq, void *platform_data)
894 {
895 	struct gc2235_device *dev = to_gc2235_sensor(sd);
896 	struct i2c_client *client = v4l2_get_subdevdata(sd);
897 	int ret = 0;
898 
899 	if (!platform_data)
900 		return -ENODEV;
901 
902 	dev->platform_data =
903 	    (struct camera_sensor_platform_data *)platform_data;
904 
905 	mutex_lock(&dev->input_lock);
906 	/* power off the module, then power on it in future
907 	 * as first power on by board may not fulfill the
908 	 * power on sequqence needed by the module
909 	 */
910 	ret = power_down(sd);
911 	if (ret) {
912 		dev_err(&client->dev, "gc2235 power-off err.\n");
913 		goto fail_power_off;
914 	}
915 
916 	ret = power_up(sd);
917 	if (ret) {
918 		dev_err(&client->dev, "gc2235 power-up err.\n");
919 		goto fail_power_on;
920 	}
921 
922 	ret = dev->platform_data->csi_cfg(sd, 1);
923 	if (ret)
924 		goto fail_csi_cfg;
925 
926 	/* config & detect sensor */
927 	ret = gc2235_detect(client);
928 	if (ret) {
929 		dev_err(&client->dev, "gc2235_detect err s_config.\n");
930 		goto fail_csi_cfg;
931 	}
932 
933 	/* turn off sensor, after probed */
934 	ret = power_down(sd);
935 	if (ret) {
936 		dev_err(&client->dev, "gc2235 power-off err.\n");
937 		goto fail_csi_cfg;
938 	}
939 	mutex_unlock(&dev->input_lock);
940 
941 	return 0;
942 
943 fail_csi_cfg:
944 	dev->platform_data->csi_cfg(sd, 0);
945 fail_power_on:
946 	power_down(sd);
947 	dev_err(&client->dev, "sensor power-gating failed\n");
948 fail_power_off:
949 	mutex_unlock(&dev->input_lock);
950 	return ret;
951 }
952 
953 static int gc2235_g_frame_interval(struct v4l2_subdev *sd,
954 				   struct v4l2_subdev_frame_interval *interval)
955 {
956 	struct gc2235_device *dev = to_gc2235_sensor(sd);
957 
958 	interval->interval.numerator = 1;
959 	interval->interval.denominator = gc2235_res[dev->fmt_idx].fps;
960 
961 	return 0;
962 }
963 
964 static int gc2235_enum_mbus_code(struct v4l2_subdev *sd,
965 				 struct v4l2_subdev_pad_config *cfg,
966 				 struct v4l2_subdev_mbus_code_enum *code)
967 {
968 	if (code->index >= MAX_FMTS)
969 		return -EINVAL;
970 
971 	code->code = MEDIA_BUS_FMT_SBGGR10_1X10;
972 	return 0;
973 }
974 
975 static int gc2235_enum_frame_size(struct v4l2_subdev *sd,
976 				  struct v4l2_subdev_pad_config *cfg,
977 				  struct v4l2_subdev_frame_size_enum *fse)
978 {
979 	int index = fse->index;
980 
981 	if (index >= N_RES)
982 		return -EINVAL;
983 
984 	fse->min_width = gc2235_res[index].width;
985 	fse->min_height = gc2235_res[index].height;
986 	fse->max_width = gc2235_res[index].width;
987 	fse->max_height = gc2235_res[index].height;
988 
989 	return 0;
990 }
991 
992 static int gc2235_g_skip_frames(struct v4l2_subdev *sd, u32 *frames)
993 {
994 	struct gc2235_device *dev = to_gc2235_sensor(sd);
995 
996 	mutex_lock(&dev->input_lock);
997 	*frames = gc2235_res[dev->fmt_idx].skip_frames;
998 	mutex_unlock(&dev->input_lock);
999 
1000 	return 0;
1001 }
1002 
1003 static const struct v4l2_subdev_sensor_ops gc2235_sensor_ops = {
1004 	.g_skip_frames	= gc2235_g_skip_frames,
1005 };
1006 
1007 static const struct v4l2_subdev_video_ops gc2235_video_ops = {
1008 	.s_stream = gc2235_s_stream,
1009 	.g_frame_interval = gc2235_g_frame_interval,
1010 };
1011 
1012 static const struct v4l2_subdev_core_ops gc2235_core_ops = {
1013 	.s_power = gc2235_s_power,
1014 	.ioctl = gc2235_ioctl,
1015 };
1016 
1017 static const struct v4l2_subdev_pad_ops gc2235_pad_ops = {
1018 	.enum_mbus_code = gc2235_enum_mbus_code,
1019 	.enum_frame_size = gc2235_enum_frame_size,
1020 	.get_fmt = gc2235_get_fmt,
1021 	.set_fmt = gc2235_set_fmt,
1022 };
1023 
1024 static const struct v4l2_subdev_ops gc2235_ops = {
1025 	.core = &gc2235_core_ops,
1026 	.video = &gc2235_video_ops,
1027 	.pad = &gc2235_pad_ops,
1028 	.sensor = &gc2235_sensor_ops,
1029 };
1030 
1031 static int gc2235_remove(struct i2c_client *client)
1032 {
1033 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
1034 	struct gc2235_device *dev = to_gc2235_sensor(sd);
1035 
1036 	dev_dbg(&client->dev, "gc2235_remove...\n");
1037 
1038 	dev->platform_data->csi_cfg(sd, 0);
1039 
1040 	v4l2_device_unregister_subdev(sd);
1041 	media_entity_cleanup(&dev->sd.entity);
1042 	v4l2_ctrl_handler_free(&dev->ctrl_handler);
1043 	kfree(dev);
1044 
1045 	return 0;
1046 }
1047 
1048 static int gc2235_probe(struct i2c_client *client)
1049 {
1050 	struct gc2235_device *dev;
1051 	void *gcpdev;
1052 	int ret;
1053 	unsigned int i;
1054 	acpi_handle handle;
1055 	struct acpi_device *adev;
1056 
1057 	handle = ACPI_HANDLE(&client->dev);
1058 	if (!handle || acpi_bus_get_device(handle, &adev)) {
1059 		dev_err(&client->dev, "Error could not get ACPI device\n");
1060 		return -ENODEV;
1061 	}
1062 	pr_info("%s: ACPI detected it on bus ID=%s, HID=%s\n",
1063 		__func__, acpi_device_bid(adev), acpi_device_hid(adev));
1064 	// FIXME: may need to release resources allocated by acpi_bus_get_device()
1065 
1066 	dev = kzalloc(sizeof(*dev), GFP_KERNEL);
1067 	if (!dev)
1068 		return -ENOMEM;
1069 
1070 	mutex_init(&dev->input_lock);
1071 
1072 	dev->fmt_idx = 0;
1073 	v4l2_i2c_subdev_init(&dev->sd, client, &gc2235_ops);
1074 
1075 	gcpdev = gmin_camera_platform_data(&dev->sd,
1076 					   ATOMISP_INPUT_FORMAT_RAW_10,
1077 					   atomisp_bayer_order_grbg);
1078 
1079 	ret = gc2235_s_config(&dev->sd, client->irq, gcpdev);
1080 	if (ret)
1081 		goto out_free;
1082 
1083 	dev->sd.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
1084 	dev->pad.flags = MEDIA_PAD_FL_SOURCE;
1085 	dev->format.code = MEDIA_BUS_FMT_SBGGR10_1X10;
1086 	dev->sd.entity.function = MEDIA_ENT_F_CAM_SENSOR;
1087 	ret =
1088 	    v4l2_ctrl_handler_init(&dev->ctrl_handler,
1089 				   ARRAY_SIZE(gc2235_controls));
1090 	if (ret) {
1091 		gc2235_remove(client);
1092 		return ret;
1093 	}
1094 
1095 	for (i = 0; i < ARRAY_SIZE(gc2235_controls); i++)
1096 		v4l2_ctrl_new_custom(&dev->ctrl_handler, &gc2235_controls[i],
1097 				     NULL);
1098 
1099 	if (dev->ctrl_handler.error) {
1100 		gc2235_remove(client);
1101 		return dev->ctrl_handler.error;
1102 	}
1103 
1104 	/* Use same lock for controls as for everything else. */
1105 	dev->ctrl_handler.lock = &dev->input_lock;
1106 	dev->sd.ctrl_handler = &dev->ctrl_handler;
1107 
1108 	ret = media_entity_pads_init(&dev->sd.entity, 1, &dev->pad);
1109 	if (ret)
1110 		gc2235_remove(client);
1111 
1112 	return atomisp_register_i2c_module(&dev->sd, gcpdev, RAW_CAMERA);
1113 
1114 out_free:
1115 	v4l2_device_unregister_subdev(&dev->sd);
1116 	kfree(dev);
1117 
1118 	return ret;
1119 }
1120 
1121 static const struct acpi_device_id gc2235_acpi_match[] = {
1122 	{ "INT33F8" },
1123 	{},
1124 };
1125 MODULE_DEVICE_TABLE(acpi, gc2235_acpi_match);
1126 
1127 static struct i2c_driver gc2235_driver = {
1128 	.driver = {
1129 		.name = "gc2235",
1130 		.acpi_match_table = gc2235_acpi_match,
1131 	},
1132 	.probe_new = gc2235_probe,
1133 	.remove = gc2235_remove,
1134 };
1135 module_i2c_driver(gc2235_driver);
1136 
1137 MODULE_AUTHOR("Shuguang Gong <Shuguang.Gong@intel.com>");
1138 MODULE_DESCRIPTION("A low-level driver for GC2235 sensors");
1139 MODULE_LICENSE("GPL");
1140