xref: /openbmc/linux/drivers/media/i2c/imx274.c (revision da27ef68751f804dbe6c2b84a49848f90ae48fd0)
1 /*
2  * imx274.c - IMX274 CMOS Image Sensor driver
3  *
4  * Copyright (C) 2017, Leopard Imaging, Inc.
5  *
6  * Leon Luo <leonl@leopardimaging.com>
7  * Edwin Zou <edwinz@leopardimaging.com>
8  *
9  * This program is free software; you can redistribute it and/or modify it
10  * under the terms and conditions of the GNU General Public License,
11  * version 2, as published by the Free Software Foundation.
12  *
13  * This program is distributed in the hope it will be useful, but WITHOUT
14  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
15  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
16  * more details.
17  *
18  * You should have received a copy of the GNU General Public License
19  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
20  */
21 
22 #include <linux/clk.h>
23 #include <linux/delay.h>
24 #include <linux/gpio.h>
25 #include <linux/gpio/consumer.h>
26 #include <linux/i2c.h>
27 #include <linux/init.h>
28 #include <linux/module.h>
29 #include <linux/of_gpio.h>
30 #include <linux/regmap.h>
31 #include <linux/slab.h>
32 #include <linux/v4l2-mediabus.h>
33 #include <linux/videodev2.h>
34 
35 #include <media/v4l2-ctrls.h>
36 #include <media/v4l2-device.h>
37 #include <media/v4l2-subdev.h>
38 
39 /*
40  * See "SHR, SVR Setting" in datasheet
41  */
42 #define IMX274_DEFAULT_FRAME_LENGTH		(4550)
43 #define IMX274_MAX_FRAME_LENGTH			(0x000fffff)
44 
45 /*
46  * See "Frame Rate Adjustment" in datasheet
47  */
48 #define IMX274_PIXCLK_CONST1			(72000000)
49 #define IMX274_PIXCLK_CONST2			(1000000)
50 
51 /*
52  * The input gain is shifted by IMX274_GAIN_SHIFT to get
53  * decimal number. The real gain is
54  * (float)input_gain_value / (1 << IMX274_GAIN_SHIFT)
55  */
56 #define IMX274_GAIN_SHIFT			(8)
57 #define IMX274_GAIN_SHIFT_MASK			((1 << IMX274_GAIN_SHIFT) - 1)
58 
59 /*
60  * See "Analog Gain" and "Digital Gain" in datasheet
61  * min gain is 1X
62  * max gain is calculated based on IMX274_GAIN_REG_MAX
63  */
64 #define IMX274_GAIN_REG_MAX			(1957)
65 #define IMX274_MIN_GAIN				(0x01 << IMX274_GAIN_SHIFT)
66 #define IMX274_MAX_ANALOG_GAIN			((2048 << IMX274_GAIN_SHIFT)\
67 					/ (2048 - IMX274_GAIN_REG_MAX))
68 #define IMX274_MAX_DIGITAL_GAIN			(8)
69 #define IMX274_DEF_GAIN				(20 << IMX274_GAIN_SHIFT)
70 #define IMX274_GAIN_CONST			(2048) /* for gain formula */
71 
72 /*
73  * 1 line time in us = (HMAX / 72), minimal is 4 lines
74  */
75 #define IMX274_MIN_EXPOSURE_TIME		(4 * 260 / 72)
76 
77 #define IMX274_DEFAULT_MODE			IMX274_MODE_3840X2160
78 #define IMX274_MAX_WIDTH			(3840)
79 #define IMX274_MAX_HEIGHT			(2160)
80 #define IMX274_MAX_FRAME_RATE			(120)
81 #define IMX274_MIN_FRAME_RATE			(5)
82 #define IMX274_DEF_FRAME_RATE			(60)
83 
84 /*
85  * register SHR is limited to (SVR value + 1) x VMAX value - 4
86  */
87 #define IMX274_SHR_LIMIT_CONST			(4)
88 
89 /*
90  * Min and max sensor reset delay (microseconds)
91  */
92 #define IMX274_RESET_DELAY1			(2000)
93 #define IMX274_RESET_DELAY2			(2200)
94 
95 /*
96  * shift and mask constants
97  */
98 #define IMX274_SHIFT_8_BITS			(8)
99 #define IMX274_SHIFT_16_BITS			(16)
100 #define IMX274_MASK_LSB_2_BITS			(0x03)
101 #define IMX274_MASK_LSB_3_BITS			(0x07)
102 #define IMX274_MASK_LSB_4_BITS			(0x0f)
103 #define IMX274_MASK_LSB_8_BITS			(0x00ff)
104 
105 #define DRIVER_NAME "IMX274"
106 
107 /*
108  * IMX274 register definitions
109  */
110 #define IMX274_SHR_REG_MSB			0x300D /* SHR */
111 #define IMX274_SHR_REG_LSB			0x300C /* SHR */
112 #define IMX274_SVR_REG_MSB			0x300F /* SVR */
113 #define IMX274_SVR_REG_LSB			0x300E /* SVR */
114 #define IMX274_VMAX_REG_1			0x30FA /* VMAX, MSB */
115 #define IMX274_VMAX_REG_2			0x30F9 /* VMAX */
116 #define IMX274_VMAX_REG_3			0x30F8 /* VMAX, LSB */
117 #define IMX274_HMAX_REG_MSB			0x30F7 /* HMAX */
118 #define IMX274_HMAX_REG_LSB			0x30F6 /* HMAX */
119 #define IMX274_ANALOG_GAIN_ADDR_LSB		0x300A /* ANALOG GAIN LSB */
120 #define IMX274_ANALOG_GAIN_ADDR_MSB		0x300B /* ANALOG GAIN MSB */
121 #define IMX274_DIGITAL_GAIN_REG			0x3012 /* Digital Gain */
122 #define IMX274_VFLIP_REG			0x301A /* VERTICAL FLIP */
123 #define IMX274_TEST_PATTERN_REG			0x303D /* TEST PATTERN */
124 #define IMX274_STANDBY_REG			0x3000 /* STANDBY */
125 
126 #define IMX274_TABLE_WAIT_MS			0
127 #define IMX274_TABLE_END			1
128 
129 /*
130  * imx274 I2C operation related structure
131  */
132 struct reg_8 {
133 	u16 addr;
134 	u8 val;
135 };
136 
137 static const struct regmap_config imx274_regmap_config = {
138 	.reg_bits = 16,
139 	.val_bits = 8,
140 	.cache_type = REGCACHE_RBTREE,
141 };
142 
143 enum imx274_mode {
144 	IMX274_MODE_3840X2160,
145 	IMX274_MODE_1920X1080,
146 	IMX274_MODE_1280X720,
147 };
148 
149 /*
150  * Parameters for each imx274 readout mode.
151  *
152  * These are the values to configure the sensor in one of the
153  * implemented modes.
154  *
155  * @size: recommended recording pixels
156  * @init_regs: registers to initialize the mode
157  * @min_frame_len: Minimum frame length for each mode (see "Frame Rate
158  *                 Adjustment (CSI-2)" in the datasheet)
159  * @min_SHR: Minimum SHR register value (see "Shutter Setting (CSI-2)" in the
160  *           datasheet)
161  * @max_fps: Maximum frames per second
162  * @nocpiop: Number of clocks per internal offset period (see "Integration Time
163  *           in Each Readout Drive Mode (CSI-2)" in the datasheet)
164  */
165 struct imx274_frmfmt {
166 	struct v4l2_frmsize_discrete size;
167 	const struct reg_8 *init_regs;
168 	int min_frame_len;
169 	int min_SHR;
170 	int max_fps;
171 	int nocpiop;
172 };
173 
174 /*
175  * imx274 test pattern related structure
176  */
177 enum {
178 	TEST_PATTERN_DISABLED = 0,
179 	TEST_PATTERN_ALL_000H,
180 	TEST_PATTERN_ALL_FFFH,
181 	TEST_PATTERN_ALL_555H,
182 	TEST_PATTERN_ALL_AAAH,
183 	TEST_PATTERN_VSP_5AH, /* VERTICAL STRIPE PATTERN 555H/AAAH */
184 	TEST_PATTERN_VSP_A5H, /* VERTICAL STRIPE PATTERN AAAH/555H */
185 	TEST_PATTERN_VSP_05H, /* VERTICAL STRIPE PATTERN 000H/555H */
186 	TEST_PATTERN_VSP_50H, /* VERTICAL STRIPE PATTERN 555H/000H */
187 	TEST_PATTERN_VSP_0FH, /* VERTICAL STRIPE PATTERN 000H/FFFH */
188 	TEST_PATTERN_VSP_F0H, /* VERTICAL STRIPE PATTERN FFFH/000H */
189 	TEST_PATTERN_H_COLOR_BARS,
190 	TEST_PATTERN_V_COLOR_BARS,
191 };
192 
193 static const char * const tp_qmenu[] = {
194 	"Disabled",
195 	"All 000h Pattern",
196 	"All FFFh Pattern",
197 	"All 555h Pattern",
198 	"All AAAh Pattern",
199 	"Vertical Stripe (555h / AAAh)",
200 	"Vertical Stripe (AAAh / 555h)",
201 	"Vertical Stripe (000h / 555h)",
202 	"Vertical Stripe (555h / 000h)",
203 	"Vertical Stripe (000h / FFFh)",
204 	"Vertical Stripe (FFFh / 000h)",
205 	"Horizontal Color Bars",
206 	"Vertical Color Bars",
207 };
208 
209 /*
210  * All-pixel scan mode (10-bit)
211  * imx274 mode1(refer to datasheet) register configuration with
212  * 3840x2160 resolution, raw10 data and mipi four lane output
213  */
214 static const struct reg_8 imx274_mode1_3840x2160_raw10[] = {
215 	{0x3004, 0x01},
216 	{0x3005, 0x01},
217 	{0x3006, 0x00},
218 	{0x3007, 0x02},
219 
220 	{0x3018, 0xA2}, /* output XVS, HVS */
221 
222 	{0x306B, 0x05},
223 	{0x30E2, 0x01},
224 	{0x30F6, 0x07}, /* HMAX, 263 */
225 	{0x30F7, 0x01}, /* HMAX */
226 
227 	{0x30dd, 0x01}, /* crop to 2160 */
228 	{0x30de, 0x06},
229 	{0x30df, 0x00},
230 	{0x30e0, 0x12},
231 	{0x30e1, 0x00},
232 	{0x3037, 0x01}, /* to crop to 3840 */
233 	{0x3038, 0x0c},
234 	{0x3039, 0x00},
235 	{0x303a, 0x0c},
236 	{0x303b, 0x0f},
237 
238 	{0x30EE, 0x01},
239 	{0x3130, 0x86},
240 	{0x3131, 0x08},
241 	{0x3132, 0x7E},
242 	{0x3133, 0x08},
243 	{0x3342, 0x0A},
244 	{0x3343, 0x00},
245 	{0x3344, 0x16},
246 	{0x3345, 0x00},
247 	{0x33A6, 0x01},
248 	{0x3528, 0x0E},
249 	{0x3554, 0x1F},
250 	{0x3555, 0x01},
251 	{0x3556, 0x01},
252 	{0x3557, 0x01},
253 	{0x3558, 0x01},
254 	{0x3559, 0x00},
255 	{0x355A, 0x00},
256 	{0x35BA, 0x0E},
257 	{0x366A, 0x1B},
258 	{0x366B, 0x1A},
259 	{0x366C, 0x19},
260 	{0x366D, 0x17},
261 	{0x3A41, 0x08},
262 
263 	{IMX274_TABLE_END, 0x00}
264 };
265 
266 /*
267  * Horizontal/vertical 2/2-line binning
268  * (Horizontal and vertical weightedbinning, 10-bit)
269  * imx274 mode3(refer to datasheet) register configuration with
270  * 1920x1080 resolution, raw10 data and mipi four lane output
271  */
272 static const struct reg_8 imx274_mode3_1920x1080_raw10[] = {
273 	{0x3004, 0x02},
274 	{0x3005, 0x21},
275 	{0x3006, 0x00},
276 	{0x3007, 0x11},
277 
278 	{0x3018, 0xA2}, /* output XVS, HVS */
279 
280 	{0x306B, 0x05},
281 	{0x30E2, 0x02},
282 
283 	{0x30F6, 0x04}, /* HMAX, 260 */
284 	{0x30F7, 0x01}, /* HMAX */
285 
286 	{0x30dd, 0x01}, /* to crop to 1920x1080 */
287 	{0x30de, 0x05},
288 	{0x30df, 0x00},
289 	{0x30e0, 0x04},
290 	{0x30e1, 0x00},
291 	{0x3037, 0x01},
292 	{0x3038, 0x0c},
293 	{0x3039, 0x00},
294 	{0x303a, 0x0c},
295 	{0x303b, 0x0f},
296 
297 	{0x30EE, 0x01},
298 	{0x3130, 0x4E},
299 	{0x3131, 0x04},
300 	{0x3132, 0x46},
301 	{0x3133, 0x04},
302 	{0x3342, 0x0A},
303 	{0x3343, 0x00},
304 	{0x3344, 0x1A},
305 	{0x3345, 0x00},
306 	{0x33A6, 0x01},
307 	{0x3528, 0x0E},
308 	{0x3554, 0x00},
309 	{0x3555, 0x01},
310 	{0x3556, 0x01},
311 	{0x3557, 0x01},
312 	{0x3558, 0x01},
313 	{0x3559, 0x00},
314 	{0x355A, 0x00},
315 	{0x35BA, 0x0E},
316 	{0x366A, 0x1B},
317 	{0x366B, 0x1A},
318 	{0x366C, 0x19},
319 	{0x366D, 0x17},
320 	{0x3A41, 0x08},
321 
322 	{IMX274_TABLE_END, 0x00}
323 };
324 
325 /*
326  * Vertical 2/3 subsampling binning horizontal 3 binning
327  * imx274 mode5(refer to datasheet) register configuration with
328  * 1280x720 resolution, raw10 data and mipi four lane output
329  */
330 static const struct reg_8 imx274_mode5_1280x720_raw10[] = {
331 	{0x3004, 0x03},
332 	{0x3005, 0x31},
333 	{0x3006, 0x00},
334 	{0x3007, 0x09},
335 
336 	{0x3018, 0xA2}, /* output XVS, HVS */
337 
338 	{0x306B, 0x05},
339 	{0x30E2, 0x03},
340 
341 	{0x30F6, 0x04}, /* HMAX, 260 */
342 	{0x30F7, 0x01}, /* HMAX */
343 
344 	{0x30DD, 0x01},
345 	{0x30DE, 0x07},
346 	{0x30DF, 0x00},
347 	{0x40E0, 0x04},
348 	{0x30E1, 0x00},
349 	{0x3030, 0xD4},
350 	{0x3031, 0x02},
351 	{0x3032, 0xD0},
352 	{0x3033, 0x02},
353 
354 	{0x30EE, 0x01},
355 	{0x3130, 0xE2},
356 	{0x3131, 0x02},
357 	{0x3132, 0xDE},
358 	{0x3133, 0x02},
359 	{0x3342, 0x0A},
360 	{0x3343, 0x00},
361 	{0x3344, 0x1B},
362 	{0x3345, 0x00},
363 	{0x33A6, 0x01},
364 	{0x3528, 0x0E},
365 	{0x3554, 0x00},
366 	{0x3555, 0x01},
367 	{0x3556, 0x01},
368 	{0x3557, 0x01},
369 	{0x3558, 0x01},
370 	{0x3559, 0x00},
371 	{0x355A, 0x00},
372 	{0x35BA, 0x0E},
373 	{0x366A, 0x1B},
374 	{0x366B, 0x19},
375 	{0x366C, 0x17},
376 	{0x366D, 0x17},
377 	{0x3A41, 0x04},
378 
379 	{IMX274_TABLE_END, 0x00}
380 };
381 
382 /*
383  * imx274 first step register configuration for
384  * starting stream
385  */
386 static const struct reg_8 imx274_start_1[] = {
387 	{IMX274_STANDBY_REG, 0x12},
388 	{IMX274_TABLE_END, 0x00}
389 };
390 
391 /*
392  * imx274 second step register configuration for
393  * starting stream
394  */
395 static const struct reg_8 imx274_start_2[] = {
396 	{0x3120, 0xF0}, /* clock settings */
397 	{0x3121, 0x00}, /* clock settings */
398 	{0x3122, 0x02}, /* clock settings */
399 	{0x3129, 0x9C}, /* clock settings */
400 	{0x312A, 0x02}, /* clock settings */
401 	{0x312D, 0x02}, /* clock settings */
402 
403 	{0x310B, 0x00},
404 
405 	/* PLSTMG */
406 	{0x304C, 0x00}, /* PLSTMG01 */
407 	{0x304D, 0x03},
408 	{0x331C, 0x1A},
409 	{0x331D, 0x00},
410 	{0x3502, 0x02},
411 	{0x3529, 0x0E},
412 	{0x352A, 0x0E},
413 	{0x352B, 0x0E},
414 	{0x3538, 0x0E},
415 	{0x3539, 0x0E},
416 	{0x3553, 0x00},
417 	{0x357D, 0x05},
418 	{0x357F, 0x05},
419 	{0x3581, 0x04},
420 	{0x3583, 0x76},
421 	{0x3587, 0x01},
422 	{0x35BB, 0x0E},
423 	{0x35BC, 0x0E},
424 	{0x35BD, 0x0E},
425 	{0x35BE, 0x0E},
426 	{0x35BF, 0x0E},
427 	{0x366E, 0x00},
428 	{0x366F, 0x00},
429 	{0x3670, 0x00},
430 	{0x3671, 0x00},
431 
432 	/* PSMIPI */
433 	{0x3304, 0x32}, /* PSMIPI1 */
434 	{0x3305, 0x00},
435 	{0x3306, 0x32},
436 	{0x3307, 0x00},
437 	{0x3590, 0x32},
438 	{0x3591, 0x00},
439 	{0x3686, 0x32},
440 	{0x3687, 0x00},
441 
442 	{IMX274_TABLE_END, 0x00}
443 };
444 
445 /*
446  * imx274 third step register configuration for
447  * starting stream
448  */
449 static const struct reg_8 imx274_start_3[] = {
450 	{IMX274_STANDBY_REG, 0x00},
451 	{0x303E, 0x02}, /* SYS_MODE = 2 */
452 	{IMX274_TABLE_END, 0x00}
453 };
454 
455 /*
456  * imx274 forth step register configuration for
457  * starting stream
458  */
459 static const struct reg_8 imx274_start_4[] = {
460 	{0x30F4, 0x00},
461 	{0x3018, 0xA2}, /* XHS VHS OUTUPT */
462 	{IMX274_TABLE_END, 0x00}
463 };
464 
465 /*
466  * imx274 register configuration for stoping stream
467  */
468 static const struct reg_8 imx274_stop[] = {
469 	{IMX274_STANDBY_REG, 0x01},
470 	{IMX274_TABLE_END, 0x00}
471 };
472 
473 /*
474  * imx274 disable test pattern register configuration
475  */
476 static const struct reg_8 imx274_tp_disabled[] = {
477 	{0x303C, 0x00},
478 	{0x377F, 0x00},
479 	{0x3781, 0x00},
480 	{0x370B, 0x00},
481 	{IMX274_TABLE_END, 0x00}
482 };
483 
484 /*
485  * imx274 test pattern register configuration
486  * reg 0x303D defines the test pattern modes
487  */
488 static const struct reg_8 imx274_tp_regs[] = {
489 	{0x303C, 0x11},
490 	{0x370E, 0x01},
491 	{0x377F, 0x01},
492 	{0x3781, 0x01},
493 	{0x370B, 0x11},
494 	{IMX274_TABLE_END, 0x00}
495 };
496 
497 /* nocpiop happens to be the same number for the implemented modes */
498 static const struct imx274_frmfmt imx274_formats[] = {
499 	{
500 		/* mode 1, 4K */
501 		.size = {3840, 2160},
502 		.init_regs = imx274_mode1_3840x2160_raw10,
503 		.min_frame_len = 4550,
504 		.min_SHR = 12,
505 		.max_fps = 60,
506 		.nocpiop = 112,
507 	},
508 	{
509 		/* mode 3, 1080p */
510 		.size = {1920, 1080},
511 		.init_regs = imx274_mode3_1920x1080_raw10,
512 		.min_frame_len = 2310,
513 		.min_SHR = 8,
514 		.max_fps = 120,
515 		.nocpiop = 112,
516 	},
517 	{
518 		/* mode 5, 720p */
519 		.size = {1280, 720},
520 		.init_regs = imx274_mode5_1280x720_raw10,
521 		.min_frame_len = 2310,
522 		.min_SHR = 8,
523 		.max_fps = 120,
524 		.nocpiop = 112,
525 	},
526 };
527 
528 /*
529  * struct imx274_ctrls - imx274 ctrl structure
530  * @handler: V4L2 ctrl handler structure
531  * @exposure: Pointer to expsure ctrl structure
532  * @gain: Pointer to gain ctrl structure
533  * @vflip: Pointer to vflip ctrl structure
534  * @test_pattern: Pointer to test pattern ctrl structure
535  */
536 struct imx274_ctrls {
537 	struct v4l2_ctrl_handler handler;
538 	struct v4l2_ctrl *exposure;
539 	struct v4l2_ctrl *gain;
540 	struct v4l2_ctrl *vflip;
541 	struct v4l2_ctrl *test_pattern;
542 };
543 
544 /*
545  * struct stim274 - imx274 device structure
546  * @sd: V4L2 subdevice structure
547  * @pad: Media pad structure
548  * @client: Pointer to I2C client
549  * @ctrls: imx274 control structure
550  * @format: V4L2 media bus frame format structure
551  * @frame_rate: V4L2 frame rate structure
552  * @regmap: Pointer to regmap structure
553  * @reset_gpio: Pointer to reset gpio
554  * @lock: Mutex structure
555  * @mode: Parameters for the selected readout mode
556  */
557 struct stimx274 {
558 	struct v4l2_subdev sd;
559 	struct media_pad pad;
560 	struct i2c_client *client;
561 	struct imx274_ctrls ctrls;
562 	struct v4l2_mbus_framefmt format;
563 	struct v4l2_fract frame_interval;
564 	struct regmap *regmap;
565 	struct gpio_desc *reset_gpio;
566 	struct mutex lock; /* mutex lock for operations */
567 	const struct imx274_frmfmt *mode;
568 };
569 
570 /*
571  * Function declaration
572  */
573 static int imx274_set_gain(struct stimx274 *priv, struct v4l2_ctrl *ctrl);
574 static int imx274_set_exposure(struct stimx274 *priv, int val);
575 static int imx274_set_vflip(struct stimx274 *priv, int val);
576 static int imx274_set_test_pattern(struct stimx274 *priv, int val);
577 static int imx274_set_frame_interval(struct stimx274 *priv,
578 				     struct v4l2_fract frame_interval);
579 
580 static inline void msleep_range(unsigned int delay_base)
581 {
582 	usleep_range(delay_base * 1000, delay_base * 1000 + 500);
583 }
584 
585 /*
586  * v4l2_ctrl and v4l2_subdev related operations
587  */
588 static inline struct v4l2_subdev *ctrl_to_sd(struct v4l2_ctrl *ctrl)
589 {
590 	return &container_of(ctrl->handler,
591 			     struct stimx274, ctrls.handler)->sd;
592 }
593 
594 static inline struct stimx274 *to_imx274(struct v4l2_subdev *sd)
595 {
596 	return container_of(sd, struct stimx274, sd);
597 }
598 
599 /*
600  * Writing a register table
601  *
602  * @priv: Pointer to device
603  * @table: Table containing register values (with optional delays)
604  *
605  * This is used to write register table into sensor's reg map.
606  *
607  * Return: 0 on success, errors otherwise
608  */
609 static int imx274_write_table(struct stimx274 *priv, const struct reg_8 table[])
610 {
611 	struct regmap *regmap = priv->regmap;
612 	int err = 0;
613 	const struct reg_8 *next;
614 	u8 val;
615 
616 	int range_start = -1;
617 	int range_count = 0;
618 	u8 range_vals[16];
619 	int max_range_vals = ARRAY_SIZE(range_vals);
620 
621 	for (next = table;; next++) {
622 		if ((next->addr != range_start + range_count) ||
623 		    (next->addr == IMX274_TABLE_END) ||
624 		    (next->addr == IMX274_TABLE_WAIT_MS) ||
625 		    (range_count == max_range_vals)) {
626 			if (range_count == 1)
627 				err = regmap_write(regmap,
628 						   range_start, range_vals[0]);
629 			else if (range_count > 1)
630 				err = regmap_bulk_write(regmap, range_start,
631 							&range_vals[0],
632 							range_count);
633 			else
634 				err = 0;
635 
636 			if (err)
637 				return err;
638 
639 			range_start = -1;
640 			range_count = 0;
641 
642 			/* Handle special address values */
643 			if (next->addr == IMX274_TABLE_END)
644 				break;
645 
646 			if (next->addr == IMX274_TABLE_WAIT_MS) {
647 				msleep_range(next->val);
648 				continue;
649 			}
650 		}
651 
652 		val = next->val;
653 
654 		if (range_start == -1)
655 			range_start = next->addr;
656 
657 		range_vals[range_count++] = val;
658 	}
659 	return 0;
660 }
661 
662 static inline int imx274_read_reg(struct stimx274 *priv, u16 addr, u8 *val)
663 {
664 	int err;
665 
666 	err = regmap_read(priv->regmap, addr, (unsigned int *)val);
667 	if (err)
668 		dev_err(&priv->client->dev,
669 			"%s : i2c read failed, addr = %x\n", __func__, addr);
670 	else
671 		dev_dbg(&priv->client->dev,
672 			"%s : addr 0x%x, val=0x%x\n", __func__,
673 			addr, *val);
674 	return err;
675 }
676 
677 static inline int imx274_write_reg(struct stimx274 *priv, u16 addr, u8 val)
678 {
679 	int err;
680 
681 	err = regmap_write(priv->regmap, addr, val);
682 	if (err)
683 		dev_err(&priv->client->dev,
684 			"%s : i2c write failed, %x = %x\n", __func__,
685 			addr, val);
686 	else
687 		dev_dbg(&priv->client->dev,
688 			"%s : addr 0x%x, val=0x%x\n", __func__,
689 			addr, val);
690 	return err;
691 }
692 
693 /*
694  * Set mode registers to start stream.
695  * @priv: Pointer to device structure
696  *
697  * Return: 0 on success, errors otherwise
698  */
699 static int imx274_mode_regs(struct stimx274 *priv)
700 {
701 	int err = 0;
702 
703 	err = imx274_write_table(priv, imx274_start_1);
704 	if (err)
705 		return err;
706 
707 	err = imx274_write_table(priv, imx274_start_2);
708 	if (err)
709 		return err;
710 
711 	err = imx274_write_table(priv, priv->mode->init_regs);
712 
713 	return err;
714 }
715 
716 /*
717  * imx274_start_stream - Function for starting stream per mode index
718  * @priv: Pointer to device structure
719  *
720  * Return: 0 on success, errors otherwise
721  */
722 static int imx274_start_stream(struct stimx274 *priv)
723 {
724 	int err = 0;
725 
726 	/*
727 	 * Refer to "Standby Cancel Sequence when using CSI-2" in
728 	 * imx274 datasheet, it should wait 10ms or more here.
729 	 * give it 1 extra ms for margin
730 	 */
731 	msleep_range(11);
732 	err = imx274_write_table(priv, imx274_start_3);
733 	if (err)
734 		return err;
735 
736 	/*
737 	 * Refer to "Standby Cancel Sequence when using CSI-2" in
738 	 * imx274 datasheet, it should wait 7ms or more here.
739 	 * give it 1 extra ms for margin
740 	 */
741 	msleep_range(8);
742 	err = imx274_write_table(priv, imx274_start_4);
743 	if (err)
744 		return err;
745 
746 	return 0;
747 }
748 
749 /*
750  * imx274_reset - Function called to reset the sensor
751  * @priv: Pointer to device structure
752  * @rst: Input value for determining the sensor's end state after reset
753  *
754  * Set the senor in reset and then
755  * if rst = 0, keep it in reset;
756  * if rst = 1, bring it out of reset.
757  *
758  */
759 static void imx274_reset(struct stimx274 *priv, int rst)
760 {
761 	gpiod_set_value_cansleep(priv->reset_gpio, 0);
762 	usleep_range(IMX274_RESET_DELAY1, IMX274_RESET_DELAY2);
763 	gpiod_set_value_cansleep(priv->reset_gpio, !!rst);
764 	usleep_range(IMX274_RESET_DELAY1, IMX274_RESET_DELAY2);
765 }
766 
767 /**
768  * imx274_s_ctrl - This is used to set the imx274 V4L2 controls
769  * @ctrl: V4L2 control to be set
770  *
771  * This function is used to set the V4L2 controls for the imx274 sensor.
772  *
773  * Return: 0 on success, errors otherwise
774  */
775 static int imx274_s_ctrl(struct v4l2_ctrl *ctrl)
776 {
777 	struct v4l2_subdev *sd = ctrl_to_sd(ctrl);
778 	struct stimx274 *imx274 = to_imx274(sd);
779 	int ret = -EINVAL;
780 
781 	dev_dbg(&imx274->client->dev,
782 		"%s : s_ctrl: %s, value: %d\n", __func__,
783 		ctrl->name, ctrl->val);
784 
785 	switch (ctrl->id) {
786 	case V4L2_CID_EXPOSURE:
787 		dev_dbg(&imx274->client->dev,
788 			"%s : set V4L2_CID_EXPOSURE\n", __func__);
789 		ret = imx274_set_exposure(imx274, ctrl->val);
790 		break;
791 
792 	case V4L2_CID_GAIN:
793 		dev_dbg(&imx274->client->dev,
794 			"%s : set V4L2_CID_GAIN\n", __func__);
795 		ret = imx274_set_gain(imx274, ctrl);
796 		break;
797 
798 	case V4L2_CID_VFLIP:
799 		dev_dbg(&imx274->client->dev,
800 			"%s : set V4L2_CID_VFLIP\n", __func__);
801 		ret = imx274_set_vflip(imx274, ctrl->val);
802 		break;
803 
804 	case V4L2_CID_TEST_PATTERN:
805 		dev_dbg(&imx274->client->dev,
806 			"%s : set V4L2_CID_TEST_PATTERN\n", __func__);
807 		ret = imx274_set_test_pattern(imx274, ctrl->val);
808 		break;
809 	}
810 
811 	return ret;
812 }
813 
814 /**
815  * imx274_get_fmt - Get the pad format
816  * @sd: Pointer to V4L2 Sub device structure
817  * @cfg: Pointer to sub device pad information structure
818  * @fmt: Pointer to pad level media bus format
819  *
820  * This function is used to get the pad format information.
821  *
822  * Return: 0 on success
823  */
824 static int imx274_get_fmt(struct v4l2_subdev *sd,
825 			  struct v4l2_subdev_pad_config *cfg,
826 			  struct v4l2_subdev_format *fmt)
827 {
828 	struct stimx274 *imx274 = to_imx274(sd);
829 
830 	mutex_lock(&imx274->lock);
831 	fmt->format = imx274->format;
832 	mutex_unlock(&imx274->lock);
833 	return 0;
834 }
835 
836 /**
837  * imx274_set_fmt - This is used to set the pad format
838  * @sd: Pointer to V4L2 Sub device structure
839  * @cfg: Pointer to sub device pad information structure
840  * @format: Pointer to pad level media bus format
841  *
842  * This function is used to set the pad format.
843  *
844  * Return: 0 on success
845  */
846 static int imx274_set_fmt(struct v4l2_subdev *sd,
847 			  struct v4l2_subdev_pad_config *cfg,
848 			  struct v4l2_subdev_format *format)
849 {
850 	struct v4l2_mbus_framefmt *fmt = &format->format;
851 	struct stimx274 *imx274 = to_imx274(sd);
852 	struct i2c_client *client = imx274->client;
853 	int index;
854 
855 	dev_dbg(&client->dev,
856 		"%s: width = %d height = %d code = %d\n",
857 		__func__, fmt->width, fmt->height, fmt->code);
858 
859 	mutex_lock(&imx274->lock);
860 
861 	for (index = 0; index < ARRAY_SIZE(imx274_formats); index++) {
862 		if (imx274_formats[index].size.width == fmt->width &&
863 		    imx274_formats[index].size.height == fmt->height)
864 			break;
865 	}
866 
867 	if (index >= ARRAY_SIZE(imx274_formats)) {
868 		/* default to first format */
869 		index = 0;
870 	}
871 
872 	imx274->mode = &imx274_formats[index];
873 
874 	if (fmt->width > IMX274_MAX_WIDTH)
875 		fmt->width = IMX274_MAX_WIDTH;
876 	if (fmt->height > IMX274_MAX_HEIGHT)
877 		fmt->height = IMX274_MAX_HEIGHT;
878 	fmt->width = fmt->width & (~IMX274_MASK_LSB_2_BITS);
879 	fmt->height = fmt->height & (~IMX274_MASK_LSB_2_BITS);
880 	fmt->field = V4L2_FIELD_NONE;
881 
882 	if (format->which == V4L2_SUBDEV_FORMAT_TRY)
883 		cfg->try_fmt = *fmt;
884 	else
885 		imx274->format = *fmt;
886 
887 	mutex_unlock(&imx274->lock);
888 	return 0;
889 }
890 
891 /**
892  * imx274_g_frame_interval - Get the frame interval
893  * @sd: Pointer to V4L2 Sub device structure
894  * @fi: Pointer to V4l2 Sub device frame interval structure
895  *
896  * This function is used to get the frame interval.
897  *
898  * Return: 0 on success
899  */
900 static int imx274_g_frame_interval(struct v4l2_subdev *sd,
901 				   struct v4l2_subdev_frame_interval *fi)
902 {
903 	struct stimx274 *imx274 = to_imx274(sd);
904 
905 	fi->interval = imx274->frame_interval;
906 	dev_dbg(&imx274->client->dev, "%s frame rate = %d / %d\n",
907 		__func__, imx274->frame_interval.numerator,
908 		imx274->frame_interval.denominator);
909 
910 	return 0;
911 }
912 
913 /**
914  * imx274_s_frame_interval - Set the frame interval
915  * @sd: Pointer to V4L2 Sub device structure
916  * @fi: Pointer to V4l2 Sub device frame interval structure
917  *
918  * This function is used to set the frame intervavl.
919  *
920  * Return: 0 on success
921  */
922 static int imx274_s_frame_interval(struct v4l2_subdev *sd,
923 				   struct v4l2_subdev_frame_interval *fi)
924 {
925 	struct stimx274 *imx274 = to_imx274(sd);
926 	struct v4l2_ctrl *ctrl = imx274->ctrls.exposure;
927 	int min, max, def;
928 	int ret;
929 
930 	mutex_lock(&imx274->lock);
931 	ret = imx274_set_frame_interval(imx274, fi->interval);
932 
933 	if (!ret) {
934 		/*
935 		 * exposure time range is decided by frame interval
936 		 * need to update it after frame interval changes
937 		 */
938 		min = IMX274_MIN_EXPOSURE_TIME;
939 		max = fi->interval.numerator * 1000000
940 			/ fi->interval.denominator;
941 		def = max;
942 		if (__v4l2_ctrl_modify_range(ctrl, min, max, 1, def)) {
943 			dev_err(&imx274->client->dev,
944 				"Exposure ctrl range update failed\n");
945 			goto unlock;
946 		}
947 
948 		/* update exposure time accordingly */
949 		imx274_set_exposure(imx274, ctrl->val);
950 
951 		dev_dbg(&imx274->client->dev, "set frame interval to %uus\n",
952 			fi->interval.numerator * 1000000
953 			/ fi->interval.denominator);
954 	}
955 
956 unlock:
957 	mutex_unlock(&imx274->lock);
958 
959 	return ret;
960 }
961 
962 /**
963  * imx274_load_default - load default control values
964  * @priv: Pointer to device structure
965  *
966  * Return: 0 on success, errors otherwise
967  */
968 static int imx274_load_default(struct stimx274 *priv)
969 {
970 	int ret;
971 
972 	/* load default control values */
973 	priv->frame_interval.numerator = 1;
974 	priv->frame_interval.denominator = IMX274_DEF_FRAME_RATE;
975 	priv->ctrls.exposure->val = 1000000 / IMX274_DEF_FRAME_RATE;
976 	priv->ctrls.gain->val = IMX274_DEF_GAIN;
977 	priv->ctrls.vflip->val = 0;
978 	priv->ctrls.test_pattern->val = TEST_PATTERN_DISABLED;
979 
980 	/* update frame rate */
981 	ret = imx274_set_frame_interval(priv,
982 					priv->frame_interval);
983 	if (ret)
984 		return ret;
985 
986 	/* update exposure time */
987 	ret = v4l2_ctrl_s_ctrl(priv->ctrls.exposure, priv->ctrls.exposure->val);
988 	if (ret)
989 		return ret;
990 
991 	/* update gain */
992 	ret = v4l2_ctrl_s_ctrl(priv->ctrls.gain, priv->ctrls.gain->val);
993 	if (ret)
994 		return ret;
995 
996 	/* update vflip */
997 	ret = v4l2_ctrl_s_ctrl(priv->ctrls.vflip, priv->ctrls.vflip->val);
998 	if (ret)
999 		return ret;
1000 
1001 	return 0;
1002 }
1003 
1004 /**
1005  * imx274_s_stream - It is used to start/stop the streaming.
1006  * @sd: V4L2 Sub device
1007  * @on: Flag (True / False)
1008  *
1009  * This function controls the start or stop of streaming for the
1010  * imx274 sensor.
1011  *
1012  * Return: 0 on success, errors otherwise
1013  */
1014 static int imx274_s_stream(struct v4l2_subdev *sd, int on)
1015 {
1016 	struct stimx274 *imx274 = to_imx274(sd);
1017 	int ret = 0;
1018 
1019 	dev_dbg(&imx274->client->dev, "%s : %s, mode index = %td\n", __func__,
1020 		on ? "Stream Start" : "Stream Stop",
1021 		imx274->mode - &imx274_formats[0]);
1022 
1023 	mutex_lock(&imx274->lock);
1024 
1025 	if (on) {
1026 		/* load mode registers */
1027 		ret = imx274_mode_regs(imx274);
1028 		if (ret)
1029 			goto fail;
1030 
1031 		/*
1032 		 * update frame rate & expsoure. if the last mode is different,
1033 		 * HMAX could be changed. As the result, frame rate & exposure
1034 		 * are changed.
1035 		 * gain is not affected.
1036 		 */
1037 		ret = imx274_set_frame_interval(imx274,
1038 						imx274->frame_interval);
1039 		if (ret)
1040 			goto fail;
1041 
1042 		/* update exposure time */
1043 		ret = __v4l2_ctrl_s_ctrl(imx274->ctrls.exposure,
1044 					 imx274->ctrls.exposure->val);
1045 		if (ret)
1046 			goto fail;
1047 
1048 		/* start stream */
1049 		ret = imx274_start_stream(imx274);
1050 		if (ret)
1051 			goto fail;
1052 	} else {
1053 		/* stop stream */
1054 		ret = imx274_write_table(imx274, imx274_stop);
1055 		if (ret)
1056 			goto fail;
1057 	}
1058 
1059 	mutex_unlock(&imx274->lock);
1060 	dev_dbg(&imx274->client->dev, "%s : Done\n", __func__);
1061 	return 0;
1062 
1063 fail:
1064 	mutex_unlock(&imx274->lock);
1065 	dev_err(&imx274->client->dev, "s_stream failed\n");
1066 	return ret;
1067 }
1068 
1069 /*
1070  * imx274_get_frame_length - Function for obtaining current frame length
1071  * @priv: Pointer to device structure
1072  * @val: Pointer to obainted value
1073  *
1074  * frame_length = vmax x (svr + 1), in unit of hmax.
1075  *
1076  * Return: 0 on success
1077  */
1078 static int imx274_get_frame_length(struct stimx274 *priv, u32 *val)
1079 {
1080 	int err;
1081 	u16 svr;
1082 	u32 vmax;
1083 	u8 reg_val[3];
1084 
1085 	/* svr */
1086 	err = imx274_read_reg(priv, IMX274_SVR_REG_LSB, &reg_val[0]);
1087 	if (err)
1088 		goto fail;
1089 
1090 	err = imx274_read_reg(priv, IMX274_SVR_REG_MSB, &reg_val[1]);
1091 	if (err)
1092 		goto fail;
1093 
1094 	svr = (reg_val[1] << IMX274_SHIFT_8_BITS) + reg_val[0];
1095 
1096 	/* vmax */
1097 	err = imx274_read_reg(priv, IMX274_VMAX_REG_3, &reg_val[0]);
1098 	if (err)
1099 		goto fail;
1100 
1101 	err = imx274_read_reg(priv, IMX274_VMAX_REG_2, &reg_val[1]);
1102 	if (err)
1103 		goto fail;
1104 
1105 	err = imx274_read_reg(priv, IMX274_VMAX_REG_1, &reg_val[2]);
1106 	if (err)
1107 		goto fail;
1108 
1109 	vmax = ((reg_val[2] & IMX274_MASK_LSB_3_BITS) << IMX274_SHIFT_16_BITS)
1110 		+ (reg_val[1] << IMX274_SHIFT_8_BITS) + reg_val[0];
1111 
1112 	*val = vmax * (svr + 1);
1113 
1114 	return 0;
1115 
1116 fail:
1117 	dev_err(&priv->client->dev, "%s error = %d\n", __func__, err);
1118 	return err;
1119 }
1120 
1121 static int imx274_clamp_coarse_time(struct stimx274 *priv, u32 *val,
1122 				    u32 *frame_length)
1123 {
1124 	int err;
1125 
1126 	err = imx274_get_frame_length(priv, frame_length);
1127 	if (err)
1128 		return err;
1129 
1130 	if (*frame_length < priv->mode->min_frame_len)
1131 		*frame_length =  priv->mode->min_frame_len;
1132 
1133 	*val = *frame_length - *val; /* convert to raw shr */
1134 	if (*val > *frame_length - IMX274_SHR_LIMIT_CONST)
1135 		*val = *frame_length - IMX274_SHR_LIMIT_CONST;
1136 	else if (*val < priv->mode->min_SHR)
1137 		*val = priv->mode->min_SHR;
1138 
1139 	return 0;
1140 }
1141 
1142 /*
1143  * imx274_set_digital gain - Function called when setting digital gain
1144  * @priv: Pointer to device structure
1145  * @dgain: Value of digital gain.
1146  *
1147  * Digital gain has only 4 steps: 1x, 2x, 4x, and 8x
1148  *
1149  * Return: 0 on success
1150  */
1151 static int imx274_set_digital_gain(struct stimx274 *priv, u32 dgain)
1152 {
1153 	u8 reg_val;
1154 
1155 	reg_val = ffs(dgain);
1156 
1157 	if (reg_val)
1158 		reg_val--;
1159 
1160 	reg_val = clamp(reg_val, (u8)0, (u8)3);
1161 
1162 	return imx274_write_reg(priv, IMX274_DIGITAL_GAIN_REG,
1163 				reg_val & IMX274_MASK_LSB_4_BITS);
1164 }
1165 
1166 static inline void imx274_calculate_gain_regs(struct reg_8 regs[2], u16 gain)
1167 {
1168 	regs->addr = IMX274_ANALOG_GAIN_ADDR_MSB;
1169 	regs->val = (gain >> IMX274_SHIFT_8_BITS) & IMX274_MASK_LSB_3_BITS;
1170 
1171 	(regs + 1)->addr = IMX274_ANALOG_GAIN_ADDR_LSB;
1172 	(regs + 1)->val = (gain) & IMX274_MASK_LSB_8_BITS;
1173 }
1174 
1175 /*
1176  * imx274_set_gain - Function called when setting gain
1177  * @priv: Pointer to device structure
1178  * @val: Value of gain. the real value = val << IMX274_GAIN_SHIFT;
1179  * @ctrl: v4l2 control pointer
1180  *
1181  * Set the gain based on input value.
1182  * The caller should hold the mutex lock imx274->lock if necessary
1183  *
1184  * Return: 0 on success
1185  */
1186 static int imx274_set_gain(struct stimx274 *priv, struct v4l2_ctrl *ctrl)
1187 {
1188 	struct reg_8 reg_list[2];
1189 	int err;
1190 	u32 gain, analog_gain, digital_gain, gain_reg;
1191 	int i;
1192 
1193 	gain = (u32)(ctrl->val);
1194 
1195 	dev_dbg(&priv->client->dev,
1196 		"%s : input gain = %d.%d\n", __func__,
1197 		gain >> IMX274_GAIN_SHIFT,
1198 		((gain & IMX274_GAIN_SHIFT_MASK) * 100) >> IMX274_GAIN_SHIFT);
1199 
1200 	if (gain > IMX274_MAX_DIGITAL_GAIN * IMX274_MAX_ANALOG_GAIN)
1201 		gain = IMX274_MAX_DIGITAL_GAIN * IMX274_MAX_ANALOG_GAIN;
1202 	else if (gain < IMX274_MIN_GAIN)
1203 		gain = IMX274_MIN_GAIN;
1204 
1205 	if (gain <= IMX274_MAX_ANALOG_GAIN)
1206 		digital_gain = 1;
1207 	else if (gain <= IMX274_MAX_ANALOG_GAIN * 2)
1208 		digital_gain = 2;
1209 	else if (gain <= IMX274_MAX_ANALOG_GAIN * 4)
1210 		digital_gain = 4;
1211 	else
1212 		digital_gain = IMX274_MAX_DIGITAL_GAIN;
1213 
1214 	analog_gain = gain / digital_gain;
1215 
1216 	dev_dbg(&priv->client->dev,
1217 		"%s : digital gain = %d, analog gain = %d.%d\n",
1218 		__func__, digital_gain, analog_gain >> IMX274_GAIN_SHIFT,
1219 		((analog_gain & IMX274_GAIN_SHIFT_MASK) * 100)
1220 		>> IMX274_GAIN_SHIFT);
1221 
1222 	err = imx274_set_digital_gain(priv, digital_gain);
1223 	if (err)
1224 		goto fail;
1225 
1226 	/* convert to register value, refer to imx274 datasheet */
1227 	gain_reg = (u32)IMX274_GAIN_CONST -
1228 		(IMX274_GAIN_CONST << IMX274_GAIN_SHIFT) / analog_gain;
1229 	if (gain_reg > IMX274_GAIN_REG_MAX)
1230 		gain_reg = IMX274_GAIN_REG_MAX;
1231 
1232 	imx274_calculate_gain_regs(reg_list, (u16)gain_reg);
1233 
1234 	for (i = 0; i < ARRAY_SIZE(reg_list); i++) {
1235 		err = imx274_write_reg(priv, reg_list[i].addr,
1236 				       reg_list[i].val);
1237 		if (err)
1238 			goto fail;
1239 	}
1240 
1241 	if (IMX274_GAIN_CONST - gain_reg == 0) {
1242 		err = -EINVAL;
1243 		goto fail;
1244 	}
1245 
1246 	/* convert register value back to gain value */
1247 	ctrl->val = (IMX274_GAIN_CONST << IMX274_GAIN_SHIFT)
1248 			/ (IMX274_GAIN_CONST - gain_reg) * digital_gain;
1249 
1250 	dev_dbg(&priv->client->dev,
1251 		"%s : GAIN control success, gain_reg = %d, new gain = %d\n",
1252 		__func__, gain_reg, ctrl->val);
1253 
1254 	return 0;
1255 
1256 fail:
1257 	dev_err(&priv->client->dev, "%s error = %d\n", __func__, err);
1258 	return err;
1259 }
1260 
1261 static inline void imx274_calculate_coarse_time_regs(struct reg_8 regs[2],
1262 						     u32 coarse_time)
1263 {
1264 	regs->addr = IMX274_SHR_REG_MSB;
1265 	regs->val = (coarse_time >> IMX274_SHIFT_8_BITS)
1266 			& IMX274_MASK_LSB_8_BITS;
1267 	(regs + 1)->addr = IMX274_SHR_REG_LSB;
1268 	(regs + 1)->val = (coarse_time) & IMX274_MASK_LSB_8_BITS;
1269 }
1270 
1271 /*
1272  * imx274_set_coarse_time - Function called when setting SHR value
1273  * @priv: Pointer to device structure
1274  * @val: Value for exposure time in number of line_length, or [HMAX]
1275  *
1276  * Set SHR value based on input value.
1277  *
1278  * Return: 0 on success
1279  */
1280 static int imx274_set_coarse_time(struct stimx274 *priv, u32 *val)
1281 {
1282 	struct reg_8 reg_list[2];
1283 	int err;
1284 	u32 coarse_time, frame_length;
1285 	int i;
1286 
1287 	coarse_time = *val;
1288 
1289 	/* convert exposure_time to appropriate SHR value */
1290 	err = imx274_clamp_coarse_time(priv, &coarse_time, &frame_length);
1291 	if (err)
1292 		goto fail;
1293 
1294 	/* prepare SHR registers */
1295 	imx274_calculate_coarse_time_regs(reg_list, coarse_time);
1296 
1297 	/* write to SHR registers */
1298 	for (i = 0; i < ARRAY_SIZE(reg_list); i++) {
1299 		err = imx274_write_reg(priv, reg_list[i].addr,
1300 				       reg_list[i].val);
1301 		if (err)
1302 			goto fail;
1303 	}
1304 
1305 	*val = frame_length - coarse_time;
1306 	return 0;
1307 
1308 fail:
1309 	dev_err(&priv->client->dev, "%s error = %d\n", __func__, err);
1310 	return err;
1311 }
1312 
1313 /*
1314  * imx274_set_exposure - Function called when setting exposure time
1315  * @priv: Pointer to device structure
1316  * @val: Variable for exposure time, in the unit of micro-second
1317  *
1318  * Set exposure time based on input value.
1319  * The caller should hold the mutex lock imx274->lock if necessary
1320  *
1321  * Return: 0 on success
1322  */
1323 static int imx274_set_exposure(struct stimx274 *priv, int val)
1324 {
1325 	int err;
1326 	u16 hmax;
1327 	u8 reg_val[2];
1328 	u32 coarse_time; /* exposure time in unit of line (HMAX)*/
1329 
1330 	dev_dbg(&priv->client->dev,
1331 		"%s : EXPOSURE control input = %d\n", __func__, val);
1332 
1333 	/* step 1: convert input exposure_time (val) into number of 1[HMAX] */
1334 
1335 	/* obtain HMAX value */
1336 	err = imx274_read_reg(priv, IMX274_HMAX_REG_LSB, &reg_val[0]);
1337 	if (err)
1338 		goto fail;
1339 	err = imx274_read_reg(priv, IMX274_HMAX_REG_MSB, &reg_val[1]);
1340 	if (err)
1341 		goto fail;
1342 	hmax = (reg_val[1] << IMX274_SHIFT_8_BITS) + reg_val[0];
1343 	if (hmax == 0) {
1344 		err = -EINVAL;
1345 		goto fail;
1346 	}
1347 
1348 	coarse_time = (IMX274_PIXCLK_CONST1 / IMX274_PIXCLK_CONST2 * val
1349 			- priv->mode->nocpiop) / hmax;
1350 
1351 	/* step 2: convert exposure_time into SHR value */
1352 
1353 	/* set SHR */
1354 	err = imx274_set_coarse_time(priv, &coarse_time);
1355 	if (err)
1356 		goto fail;
1357 
1358 	priv->ctrls.exposure->val =
1359 			(coarse_time * hmax + priv->mode->nocpiop)
1360 			/ (IMX274_PIXCLK_CONST1 / IMX274_PIXCLK_CONST2);
1361 
1362 	dev_dbg(&priv->client->dev,
1363 		"%s : EXPOSURE control success\n", __func__);
1364 	return 0;
1365 
1366 fail:
1367 	dev_err(&priv->client->dev, "%s error = %d\n", __func__, err);
1368 
1369 	return err;
1370 }
1371 
1372 /*
1373  * imx274_set_vflip - Function called when setting vertical flip
1374  * @priv: Pointer to device structure
1375  * @val: Value for vflip setting
1376  *
1377  * Set vertical flip based on input value.
1378  * val = 0: normal, no vertical flip
1379  * val = 1: vertical flip enabled
1380  * The caller should hold the mutex lock imx274->lock if necessary
1381  *
1382  * Return: 0 on success
1383  */
1384 static int imx274_set_vflip(struct stimx274 *priv, int val)
1385 {
1386 	int err;
1387 
1388 	err = imx274_write_reg(priv, IMX274_VFLIP_REG, val);
1389 	if (err) {
1390 		dev_err(&priv->client->dev, "VFLIP control error\n");
1391 		return err;
1392 	}
1393 
1394 	dev_dbg(&priv->client->dev,
1395 		"%s : VFLIP control success\n", __func__);
1396 
1397 	return 0;
1398 }
1399 
1400 /*
1401  * imx274_set_test_pattern - Function called when setting test pattern
1402  * @priv: Pointer to device structure
1403  * @val: Variable for test pattern
1404  *
1405  * Set to different test patterns based on input value.
1406  *
1407  * Return: 0 on success
1408  */
1409 static int imx274_set_test_pattern(struct stimx274 *priv, int val)
1410 {
1411 	int err = 0;
1412 
1413 	if (val == TEST_PATTERN_DISABLED) {
1414 		err = imx274_write_table(priv, imx274_tp_disabled);
1415 	} else if (val <= TEST_PATTERN_V_COLOR_BARS) {
1416 		err = imx274_write_reg(priv, IMX274_TEST_PATTERN_REG, val - 1);
1417 		if (!err)
1418 			err = imx274_write_table(priv, imx274_tp_regs);
1419 	} else {
1420 		err = -EINVAL;
1421 	}
1422 
1423 	if (!err)
1424 		dev_dbg(&priv->client->dev,
1425 			"%s : TEST PATTERN control success\n", __func__);
1426 	else
1427 		dev_err(&priv->client->dev, "%s error = %d\n", __func__, err);
1428 
1429 	return err;
1430 }
1431 
1432 static inline void imx274_calculate_frame_length_regs(struct reg_8 regs[3],
1433 						      u32 frame_length)
1434 {
1435 	regs->addr = IMX274_VMAX_REG_1;
1436 	regs->val = (frame_length >> IMX274_SHIFT_16_BITS)
1437 			& IMX274_MASK_LSB_4_BITS;
1438 	(regs + 1)->addr = IMX274_VMAX_REG_2;
1439 	(regs + 1)->val = (frame_length >> IMX274_SHIFT_8_BITS)
1440 			& IMX274_MASK_LSB_8_BITS;
1441 	(regs + 2)->addr = IMX274_VMAX_REG_3;
1442 	(regs + 2)->val = (frame_length) & IMX274_MASK_LSB_8_BITS;
1443 }
1444 
1445 /*
1446  * imx274_set_frame_length - Function called when setting frame length
1447  * @priv: Pointer to device structure
1448  * @val: Variable for frame length (= VMAX, i.e. vertical drive period length)
1449  *
1450  * Set frame length based on input value.
1451  *
1452  * Return: 0 on success
1453  */
1454 static int imx274_set_frame_length(struct stimx274 *priv, u32 val)
1455 {
1456 	struct reg_8 reg_list[3];
1457 	int err;
1458 	u32 frame_length;
1459 	int i;
1460 
1461 	dev_dbg(&priv->client->dev, "%s : input length = %d\n",
1462 		__func__, val);
1463 
1464 	frame_length = (u32)val;
1465 
1466 	imx274_calculate_frame_length_regs(reg_list, frame_length);
1467 	for (i = 0; i < ARRAY_SIZE(reg_list); i++) {
1468 		err = imx274_write_reg(priv, reg_list[i].addr,
1469 				       reg_list[i].val);
1470 		if (err)
1471 			goto fail;
1472 	}
1473 
1474 	return 0;
1475 
1476 fail:
1477 	dev_err(&priv->client->dev, "%s error = %d\n", __func__, err);
1478 	return err;
1479 }
1480 
1481 /*
1482  * imx274_set_frame_interval - Function called when setting frame interval
1483  * @priv: Pointer to device structure
1484  * @frame_interval: Variable for frame interval
1485  *
1486  * Change frame interval by updating VMAX value
1487  * The caller should hold the mutex lock imx274->lock if necessary
1488  *
1489  * Return: 0 on success
1490  */
1491 static int imx274_set_frame_interval(struct stimx274 *priv,
1492 				     struct v4l2_fract frame_interval)
1493 {
1494 	int err;
1495 	u32 frame_length, req_frame_rate;
1496 	u16 svr;
1497 	u16 hmax;
1498 	u8 reg_val[2];
1499 
1500 	dev_dbg(&priv->client->dev, "%s: input frame interval = %d / %d",
1501 		__func__, frame_interval.numerator,
1502 		frame_interval.denominator);
1503 
1504 	if (frame_interval.numerator == 0) {
1505 		err = -EINVAL;
1506 		goto fail;
1507 	}
1508 
1509 	req_frame_rate = (u32)(frame_interval.denominator
1510 				/ frame_interval.numerator);
1511 
1512 	/* boundary check */
1513 	if (req_frame_rate > priv->mode->max_fps) {
1514 		frame_interval.numerator = 1;
1515 		frame_interval.denominator = priv->mode->max_fps;
1516 	} else if (req_frame_rate < IMX274_MIN_FRAME_RATE) {
1517 		frame_interval.numerator = 1;
1518 		frame_interval.denominator = IMX274_MIN_FRAME_RATE;
1519 	}
1520 
1521 	/*
1522 	 * VMAX = 1/frame_rate x 72M / (SVR+1) / HMAX
1523 	 * frame_length (i.e. VMAX) = (frame_interval) x 72M /(SVR+1) / HMAX
1524 	 */
1525 
1526 	/* SVR */
1527 	err = imx274_read_reg(priv, IMX274_SVR_REG_LSB, &reg_val[0]);
1528 	if (err)
1529 		goto fail;
1530 	err = imx274_read_reg(priv, IMX274_SVR_REG_MSB, &reg_val[1]);
1531 	if (err)
1532 		goto fail;
1533 	svr = (reg_val[1] << IMX274_SHIFT_8_BITS) + reg_val[0];
1534 	dev_dbg(&priv->client->dev,
1535 		"%s : register SVR = %d\n", __func__, svr);
1536 
1537 	/* HMAX */
1538 	err = imx274_read_reg(priv, IMX274_HMAX_REG_LSB, &reg_val[0]);
1539 	if (err)
1540 		goto fail;
1541 	err = imx274_read_reg(priv, IMX274_HMAX_REG_MSB, &reg_val[1]);
1542 	if (err)
1543 		goto fail;
1544 	hmax = (reg_val[1] << IMX274_SHIFT_8_BITS) + reg_val[0];
1545 	dev_dbg(&priv->client->dev,
1546 		"%s : register HMAX = %d\n", __func__, hmax);
1547 
1548 	if (hmax == 0 || frame_interval.denominator == 0) {
1549 		err = -EINVAL;
1550 		goto fail;
1551 	}
1552 
1553 	frame_length = IMX274_PIXCLK_CONST1 / (svr + 1) / hmax
1554 					* frame_interval.numerator
1555 					/ frame_interval.denominator;
1556 
1557 	err = imx274_set_frame_length(priv, frame_length);
1558 	if (err)
1559 		goto fail;
1560 
1561 	priv->frame_interval = frame_interval;
1562 	return 0;
1563 
1564 fail:
1565 	dev_err(&priv->client->dev, "%s error = %d\n", __func__, err);
1566 	return err;
1567 }
1568 
1569 static const struct v4l2_subdev_pad_ops imx274_pad_ops = {
1570 	.get_fmt = imx274_get_fmt,
1571 	.set_fmt = imx274_set_fmt,
1572 };
1573 
1574 static const struct v4l2_subdev_video_ops imx274_video_ops = {
1575 	.g_frame_interval = imx274_g_frame_interval,
1576 	.s_frame_interval = imx274_s_frame_interval,
1577 	.s_stream = imx274_s_stream,
1578 };
1579 
1580 static const struct v4l2_subdev_ops imx274_subdev_ops = {
1581 	.pad = &imx274_pad_ops,
1582 	.video = &imx274_video_ops,
1583 };
1584 
1585 static const struct v4l2_ctrl_ops imx274_ctrl_ops = {
1586 	.s_ctrl	= imx274_s_ctrl,
1587 };
1588 
1589 static const struct of_device_id imx274_of_id_table[] = {
1590 	{ .compatible = "sony,imx274" },
1591 	{ }
1592 };
1593 MODULE_DEVICE_TABLE(of, imx274_of_id_table);
1594 
1595 static const struct i2c_device_id imx274_id[] = {
1596 	{ "IMX274", 0 },
1597 	{ }
1598 };
1599 MODULE_DEVICE_TABLE(i2c, imx274_id);
1600 
1601 static int imx274_probe(struct i2c_client *client,
1602 			const struct i2c_device_id *id)
1603 {
1604 	struct v4l2_subdev *sd;
1605 	struct stimx274 *imx274;
1606 	int ret;
1607 
1608 	/* initialize imx274 */
1609 	imx274 = devm_kzalloc(&client->dev, sizeof(*imx274), GFP_KERNEL);
1610 	if (!imx274)
1611 		return -ENOMEM;
1612 
1613 	mutex_init(&imx274->lock);
1614 
1615 	/* initialize format */
1616 	imx274->mode = &imx274_formats[IMX274_DEFAULT_MODE];
1617 	imx274->format.width = imx274->mode->size.width;
1618 	imx274->format.height = imx274->mode->size.height;
1619 	imx274->format.field = V4L2_FIELD_NONE;
1620 	imx274->format.code = MEDIA_BUS_FMT_SRGGB10_1X10;
1621 	imx274->format.colorspace = V4L2_COLORSPACE_SRGB;
1622 	imx274->frame_interval.numerator = 1;
1623 	imx274->frame_interval.denominator = IMX274_DEF_FRAME_RATE;
1624 
1625 	/* initialize regmap */
1626 	imx274->regmap = devm_regmap_init_i2c(client, &imx274_regmap_config);
1627 	if (IS_ERR(imx274->regmap)) {
1628 		dev_err(&client->dev,
1629 			"regmap init failed: %ld\n", PTR_ERR(imx274->regmap));
1630 		ret = -ENODEV;
1631 		goto err_regmap;
1632 	}
1633 
1634 	/* initialize subdevice */
1635 	imx274->client = client;
1636 	sd = &imx274->sd;
1637 	v4l2_i2c_subdev_init(sd, client, &imx274_subdev_ops);
1638 	strlcpy(sd->name, DRIVER_NAME, sizeof(sd->name));
1639 	sd->flags |= V4L2_SUBDEV_FL_HAS_DEVNODE | V4L2_SUBDEV_FL_HAS_EVENTS;
1640 
1641 	/* initialize subdev media pad */
1642 	imx274->pad.flags = MEDIA_PAD_FL_SOURCE;
1643 	sd->entity.function = MEDIA_ENT_F_CAM_SENSOR;
1644 	ret = media_entity_pads_init(&sd->entity, 1, &imx274->pad);
1645 	if (ret < 0) {
1646 		dev_err(&client->dev,
1647 			"%s : media entity init Failed %d\n", __func__, ret);
1648 		goto err_regmap;
1649 	}
1650 
1651 	/* initialize sensor reset gpio */
1652 	imx274->reset_gpio = devm_gpiod_get_optional(&client->dev, "reset",
1653 						     GPIOD_OUT_HIGH);
1654 	if (IS_ERR(imx274->reset_gpio)) {
1655 		if (PTR_ERR(imx274->reset_gpio) != -EPROBE_DEFER)
1656 			dev_err(&client->dev, "Reset GPIO not setup in DT");
1657 		ret = PTR_ERR(imx274->reset_gpio);
1658 		goto err_me;
1659 	}
1660 
1661 	/* pull sensor out of reset */
1662 	imx274_reset(imx274, 1);
1663 
1664 	/* initialize controls */
1665 	ret = v4l2_ctrl_handler_init(&imx274->ctrls.handler, 2);
1666 	if (ret < 0) {
1667 		dev_err(&client->dev,
1668 			"%s : ctrl handler init Failed\n", __func__);
1669 		goto err_me;
1670 	}
1671 
1672 	imx274->ctrls.handler.lock = &imx274->lock;
1673 
1674 	/* add new controls */
1675 	imx274->ctrls.test_pattern = v4l2_ctrl_new_std_menu_items(
1676 		&imx274->ctrls.handler, &imx274_ctrl_ops,
1677 		V4L2_CID_TEST_PATTERN,
1678 		ARRAY_SIZE(tp_qmenu) - 1, 0, 0, tp_qmenu);
1679 
1680 	imx274->ctrls.gain = v4l2_ctrl_new_std(
1681 		&imx274->ctrls.handler,
1682 		&imx274_ctrl_ops,
1683 		V4L2_CID_GAIN, IMX274_MIN_GAIN,
1684 		IMX274_MAX_DIGITAL_GAIN * IMX274_MAX_ANALOG_GAIN, 1,
1685 		IMX274_DEF_GAIN);
1686 
1687 	imx274->ctrls.exposure = v4l2_ctrl_new_std(
1688 		&imx274->ctrls.handler,
1689 		&imx274_ctrl_ops,
1690 		V4L2_CID_EXPOSURE, IMX274_MIN_EXPOSURE_TIME,
1691 		1000000 / IMX274_DEF_FRAME_RATE, 1,
1692 		IMX274_MIN_EXPOSURE_TIME);
1693 
1694 	imx274->ctrls.vflip = v4l2_ctrl_new_std(
1695 		&imx274->ctrls.handler,
1696 		&imx274_ctrl_ops,
1697 		V4L2_CID_VFLIP, 0, 1, 1, 0);
1698 
1699 	imx274->sd.ctrl_handler = &imx274->ctrls.handler;
1700 	if (imx274->ctrls.handler.error) {
1701 		ret = imx274->ctrls.handler.error;
1702 		goto err_ctrls;
1703 	}
1704 
1705 	/* setup default controls */
1706 	ret = v4l2_ctrl_handler_setup(&imx274->ctrls.handler);
1707 	if (ret) {
1708 		dev_err(&client->dev,
1709 			"Error %d setup default controls\n", ret);
1710 		goto err_ctrls;
1711 	}
1712 
1713 	/* load default control values */
1714 	ret = imx274_load_default(imx274);
1715 	if (ret) {
1716 		dev_err(&client->dev,
1717 			"%s : imx274_load_default failed %d\n",
1718 			__func__, ret);
1719 		goto err_ctrls;
1720 	}
1721 
1722 	/* register subdevice */
1723 	ret = v4l2_async_register_subdev(sd);
1724 	if (ret < 0) {
1725 		dev_err(&client->dev,
1726 			"%s : v4l2_async_register_subdev failed %d\n",
1727 			__func__, ret);
1728 		goto err_ctrls;
1729 	}
1730 
1731 	dev_info(&client->dev, "imx274 : imx274 probe success !\n");
1732 	return 0;
1733 
1734 err_ctrls:
1735 	v4l2_ctrl_handler_free(&imx274->ctrls.handler);
1736 err_me:
1737 	media_entity_cleanup(&sd->entity);
1738 err_regmap:
1739 	mutex_destroy(&imx274->lock);
1740 	return ret;
1741 }
1742 
1743 static int imx274_remove(struct i2c_client *client)
1744 {
1745 	struct v4l2_subdev *sd = i2c_get_clientdata(client);
1746 	struct stimx274 *imx274 = to_imx274(sd);
1747 
1748 	/* stop stream */
1749 	imx274_write_table(imx274, imx274_stop);
1750 
1751 	v4l2_async_unregister_subdev(sd);
1752 	v4l2_ctrl_handler_free(&imx274->ctrls.handler);
1753 	media_entity_cleanup(&sd->entity);
1754 	mutex_destroy(&imx274->lock);
1755 	return 0;
1756 }
1757 
1758 static struct i2c_driver imx274_i2c_driver = {
1759 	.driver = {
1760 		.name	= DRIVER_NAME,
1761 		.of_match_table	= imx274_of_id_table,
1762 	},
1763 	.probe		= imx274_probe,
1764 	.remove		= imx274_remove,
1765 	.id_table	= imx274_id,
1766 };
1767 
1768 module_i2c_driver(imx274_i2c_driver);
1769 
1770 MODULE_AUTHOR("Leon Luo <leonl@leopardimaging.com>");
1771 MODULE_DESCRIPTION("IMX274 CMOS Image Sensor driver");
1772 MODULE_LICENSE("GPL v2");
1773