xref: /openbmc/linux/drivers/media/i2c/lm3646.c (revision e3b9f1e8)
1 /*
2  * drivers/media/i2c/lm3646.c
3  * General device driver for TI lm3646, Dual FLASH LED Driver
4  *
5  * Copyright (C) 2014 Texas Instruments
6  *
7  * Contact: Daniel Jeong <gshark.jeong@gmail.com>
8  *			Ldd-Mlp <ldd-mlp@list.ti.com>
9  *
10  * This program is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU General Public License
12  * version 2 as published by the Free Software Foundation.
13  */
14 
15 #include <linux/delay.h>
16 #include <linux/i2c.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/regmap.h>
20 #include <linux/videodev2.h>
21 #include <media/i2c/lm3646.h>
22 #include <media/v4l2-ctrls.h>
23 #include <media/v4l2-device.h>
24 
25 /* registers definitions */
26 #define REG_ENABLE		0x01
27 #define REG_TORCH_BR	0x05
28 #define REG_FLASH_BR	0x05
29 #define REG_FLASH_TOUT	0x04
30 #define REG_FLAG		0x08
31 #define REG_STROBE_SRC	0x06
32 #define REG_LED1_FLASH_BR 0x06
33 #define REG_LED1_TORCH_BR 0x07
34 
35 #define MASK_ENABLE		0x03
36 #define MASK_TORCH_BR	0x70
37 #define MASK_FLASH_BR	0x0F
38 #define MASK_FLASH_TOUT	0x07
39 #define MASK_FLAG		0xFF
40 #define MASK_STROBE_SRC	0x80
41 
42 /* Fault Mask */
43 #define FAULT_TIMEOUT	(1<<0)
44 #define FAULT_SHORT_CIRCUIT	(1<<1)
45 #define FAULT_UVLO		(1<<2)
46 #define FAULT_IVFM		(1<<3)
47 #define FAULT_OCP		(1<<4)
48 #define FAULT_OVERTEMP	(1<<5)
49 #define FAULT_NTC_TRIP	(1<<6)
50 #define FAULT_OVP		(1<<7)
51 
52 enum led_mode {
53 	MODE_SHDN = 0x0,
54 	MODE_TORCH = 0x2,
55 	MODE_FLASH = 0x3,
56 };
57 
58 /*
59  * struct lm3646_flash
60  *
61  * @pdata: platform data
62  * @regmap: reg. map for i2c
63  * @lock: muxtex for serial access.
64  * @led_mode: V4L2 LED mode
65  * @ctrls_led: V4L2 contols
66  * @subdev_led: V4L2 subdev
67  * @mode_reg : mode register value
68  */
69 struct lm3646_flash {
70 	struct device *dev;
71 	struct lm3646_platform_data *pdata;
72 	struct regmap *regmap;
73 
74 	struct v4l2_ctrl_handler ctrls_led;
75 	struct v4l2_subdev subdev_led;
76 
77 	u8 mode_reg;
78 };
79 
80 #define to_lm3646_flash(_ctrl)	\
81 	container_of(_ctrl->handler, struct lm3646_flash, ctrls_led)
82 
83 /* enable mode control */
84 static int lm3646_mode_ctrl(struct lm3646_flash *flash,
85 			    enum v4l2_flash_led_mode led_mode)
86 {
87 	switch (led_mode) {
88 	case V4L2_FLASH_LED_MODE_NONE:
89 		return regmap_write(flash->regmap,
90 				    REG_ENABLE, flash->mode_reg | MODE_SHDN);
91 	case V4L2_FLASH_LED_MODE_TORCH:
92 		return regmap_write(flash->regmap,
93 				    REG_ENABLE, flash->mode_reg | MODE_TORCH);
94 	case V4L2_FLASH_LED_MODE_FLASH:
95 		return regmap_write(flash->regmap,
96 				    REG_ENABLE, flash->mode_reg | MODE_FLASH);
97 	}
98 	return -EINVAL;
99 }
100 
101 /* V4L2 controls  */
102 static int lm3646_get_ctrl(struct v4l2_ctrl *ctrl)
103 {
104 	struct lm3646_flash *flash = to_lm3646_flash(ctrl);
105 	unsigned int reg_val;
106 	int rval;
107 
108 	if (ctrl->id != V4L2_CID_FLASH_FAULT)
109 		return -EINVAL;
110 
111 	rval = regmap_read(flash->regmap, REG_FLAG, &reg_val);
112 	if (rval < 0)
113 		return rval;
114 
115 	ctrl->val = 0;
116 	if (reg_val & FAULT_TIMEOUT)
117 		ctrl->val |= V4L2_FLASH_FAULT_TIMEOUT;
118 	if (reg_val & FAULT_SHORT_CIRCUIT)
119 		ctrl->val |= V4L2_FLASH_FAULT_SHORT_CIRCUIT;
120 	if (reg_val & FAULT_UVLO)
121 		ctrl->val |= V4L2_FLASH_FAULT_UNDER_VOLTAGE;
122 	if (reg_val & FAULT_IVFM)
123 		ctrl->val |= V4L2_FLASH_FAULT_INPUT_VOLTAGE;
124 	if (reg_val & FAULT_OCP)
125 		ctrl->val |= V4L2_FLASH_FAULT_OVER_CURRENT;
126 	if (reg_val & FAULT_OVERTEMP)
127 		ctrl->val |= V4L2_FLASH_FAULT_OVER_TEMPERATURE;
128 	if (reg_val & FAULT_NTC_TRIP)
129 		ctrl->val |= V4L2_FLASH_FAULT_LED_OVER_TEMPERATURE;
130 	if (reg_val & FAULT_OVP)
131 		ctrl->val |= V4L2_FLASH_FAULT_OVER_VOLTAGE;
132 
133 	return 0;
134 }
135 
136 static int lm3646_set_ctrl(struct v4l2_ctrl *ctrl)
137 {
138 	struct lm3646_flash *flash = to_lm3646_flash(ctrl);
139 	unsigned int reg_val;
140 	int rval = -EINVAL;
141 
142 	switch (ctrl->id) {
143 	case V4L2_CID_FLASH_LED_MODE:
144 
145 		if (ctrl->val != V4L2_FLASH_LED_MODE_FLASH)
146 			return lm3646_mode_ctrl(flash, ctrl->val);
147 		/* switch to SHDN mode before flash strobe on */
148 		return lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_NONE);
149 
150 	case V4L2_CID_FLASH_STROBE_SOURCE:
151 		return regmap_update_bits(flash->regmap,
152 					  REG_STROBE_SRC, MASK_STROBE_SRC,
153 					  (ctrl->val) << 7);
154 
155 	case V4L2_CID_FLASH_STROBE:
156 
157 		/* read and check current mode of chip to start flash */
158 		rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
159 		if (rval < 0 || ((reg_val & MASK_ENABLE) != MODE_SHDN))
160 			return rval;
161 		/* flash on */
162 		return lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_FLASH);
163 
164 	case V4L2_CID_FLASH_STROBE_STOP:
165 
166 		/*
167 		 * flash mode will be turned automatically
168 		 * from FLASH mode to SHDN mode after flash duration timeout
169 		 * read and check current mode of chip to stop flash
170 		 */
171 		rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
172 		if (rval < 0)
173 			return rval;
174 		if ((reg_val & MASK_ENABLE) == MODE_FLASH)
175 			return lm3646_mode_ctrl(flash,
176 						V4L2_FLASH_LED_MODE_NONE);
177 		return rval;
178 
179 	case V4L2_CID_FLASH_TIMEOUT:
180 		return regmap_update_bits(flash->regmap,
181 					  REG_FLASH_TOUT, MASK_FLASH_TOUT,
182 					  LM3646_FLASH_TOUT_ms_TO_REG
183 					  (ctrl->val));
184 
185 	case V4L2_CID_FLASH_INTENSITY:
186 		return regmap_update_bits(flash->regmap,
187 					  REG_FLASH_BR, MASK_FLASH_BR,
188 					  LM3646_TOTAL_FLASH_BRT_uA_TO_REG
189 					  (ctrl->val));
190 
191 	case V4L2_CID_FLASH_TORCH_INTENSITY:
192 		return regmap_update_bits(flash->regmap,
193 					  REG_TORCH_BR, MASK_TORCH_BR,
194 					  LM3646_TOTAL_TORCH_BRT_uA_TO_REG
195 					  (ctrl->val) << 4);
196 	}
197 
198 	return -EINVAL;
199 }
200 
201 static const struct v4l2_ctrl_ops lm3646_led_ctrl_ops = {
202 	.g_volatile_ctrl = lm3646_get_ctrl,
203 	.s_ctrl = lm3646_set_ctrl,
204 };
205 
206 static int lm3646_init_controls(struct lm3646_flash *flash)
207 {
208 	struct v4l2_ctrl *fault;
209 	struct v4l2_ctrl_handler *hdl = &flash->ctrls_led;
210 	const struct v4l2_ctrl_ops *ops = &lm3646_led_ctrl_ops;
211 
212 	v4l2_ctrl_handler_init(hdl, 8);
213 	/* flash mode */
214 	v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_FLASH_LED_MODE,
215 			       V4L2_FLASH_LED_MODE_TORCH, ~0x7,
216 			       V4L2_FLASH_LED_MODE_NONE);
217 
218 	/* flash source */
219 	v4l2_ctrl_new_std_menu(hdl, ops, V4L2_CID_FLASH_STROBE_SOURCE,
220 			       0x1, ~0x3, V4L2_FLASH_STROBE_SOURCE_SOFTWARE);
221 
222 	/* flash strobe */
223 	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_STROBE, 0, 0, 0, 0);
224 	/* flash strobe stop */
225 	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_STROBE_STOP, 0, 0, 0, 0);
226 
227 	/* flash strobe timeout */
228 	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_TIMEOUT,
229 			  LM3646_FLASH_TOUT_MIN,
230 			  LM3646_FLASH_TOUT_MAX,
231 			  LM3646_FLASH_TOUT_STEP, flash->pdata->flash_timeout);
232 
233 	/* max flash current */
234 	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_INTENSITY,
235 			  LM3646_TOTAL_FLASH_BRT_MIN,
236 			  LM3646_TOTAL_FLASH_BRT_MAX,
237 			  LM3646_TOTAL_FLASH_BRT_STEP,
238 			  LM3646_TOTAL_FLASH_BRT_MAX);
239 
240 	/* max torch current */
241 	v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_TORCH_INTENSITY,
242 			  LM3646_TOTAL_TORCH_BRT_MIN,
243 			  LM3646_TOTAL_TORCH_BRT_MAX,
244 			  LM3646_TOTAL_TORCH_BRT_STEP,
245 			  LM3646_TOTAL_TORCH_BRT_MAX);
246 
247 	/* fault */
248 	fault = v4l2_ctrl_new_std(hdl, ops, V4L2_CID_FLASH_FAULT, 0,
249 				  V4L2_FLASH_FAULT_OVER_VOLTAGE
250 				  | V4L2_FLASH_FAULT_OVER_TEMPERATURE
251 				  | V4L2_FLASH_FAULT_SHORT_CIRCUIT
252 				  | V4L2_FLASH_FAULT_TIMEOUT, 0, 0);
253 	if (fault != NULL)
254 		fault->flags |= V4L2_CTRL_FLAG_VOLATILE;
255 
256 	if (hdl->error)
257 		return hdl->error;
258 
259 	flash->subdev_led.ctrl_handler = hdl;
260 	return 0;
261 }
262 
263 /* initialize device */
264 static const struct v4l2_subdev_ops lm3646_ops = {
265 	.core = NULL,
266 };
267 
268 static const struct regmap_config lm3646_regmap = {
269 	.reg_bits = 8,
270 	.val_bits = 8,
271 	.max_register = 0xFF,
272 };
273 
274 static int lm3646_subdev_init(struct lm3646_flash *flash)
275 {
276 	struct i2c_client *client = to_i2c_client(flash->dev);
277 	int rval;
278 
279 	v4l2_i2c_subdev_init(&flash->subdev_led, client, &lm3646_ops);
280 	flash->subdev_led.flags |= V4L2_SUBDEV_FL_HAS_DEVNODE;
281 	strcpy(flash->subdev_led.name, LM3646_NAME);
282 	rval = lm3646_init_controls(flash);
283 	if (rval)
284 		goto err_out;
285 	rval = media_entity_pads_init(&flash->subdev_led.entity, 0, NULL);
286 	if (rval < 0)
287 		goto err_out;
288 	flash->subdev_led.entity.function = MEDIA_ENT_F_FLASH;
289 	return rval;
290 
291 err_out:
292 	v4l2_ctrl_handler_free(&flash->ctrls_led);
293 	return rval;
294 }
295 
296 static int lm3646_init_device(struct lm3646_flash *flash)
297 {
298 	unsigned int reg_val;
299 	int rval;
300 
301 	/* read the value of mode register to reduce redundant i2c accesses */
302 	rval = regmap_read(flash->regmap, REG_ENABLE, &reg_val);
303 	if (rval < 0)
304 		return rval;
305 	flash->mode_reg = reg_val & 0xfc;
306 
307 	/* output disable */
308 	rval = lm3646_mode_ctrl(flash, V4L2_FLASH_LED_MODE_NONE);
309 	if (rval < 0)
310 		return rval;
311 
312 	/*
313 	 * LED1 flash current setting
314 	 * LED2 flash current = Total(Max) flash current - LED1 flash current
315 	 */
316 	rval = regmap_update_bits(flash->regmap,
317 				  REG_LED1_FLASH_BR, 0x7F,
318 				  LM3646_LED1_FLASH_BRT_uA_TO_REG
319 				  (flash->pdata->led1_flash_brt));
320 
321 	if (rval < 0)
322 		return rval;
323 
324 	/*
325 	 * LED1 torch current setting
326 	 * LED2 torch current = Total(Max) torch current - LED1 torch current
327 	 */
328 	rval = regmap_update_bits(flash->regmap,
329 				  REG_LED1_TORCH_BR, 0x7F,
330 				  LM3646_LED1_TORCH_BRT_uA_TO_REG
331 				  (flash->pdata->led1_torch_brt));
332 	if (rval < 0)
333 		return rval;
334 
335 	/* Reset flag register */
336 	return regmap_read(flash->regmap, REG_FLAG, &reg_val);
337 }
338 
339 static int lm3646_probe(struct i2c_client *client,
340 			const struct i2c_device_id *devid)
341 {
342 	struct lm3646_flash *flash;
343 	struct lm3646_platform_data *pdata = dev_get_platdata(&client->dev);
344 	int rval;
345 
346 	flash = devm_kzalloc(&client->dev, sizeof(*flash), GFP_KERNEL);
347 	if (flash == NULL)
348 		return -ENOMEM;
349 
350 	flash->regmap = devm_regmap_init_i2c(client, &lm3646_regmap);
351 	if (IS_ERR(flash->regmap))
352 		return PTR_ERR(flash->regmap);
353 
354 	/* check device tree if there is no platform data */
355 	if (pdata == NULL) {
356 		pdata = devm_kzalloc(&client->dev,
357 				     sizeof(struct lm3646_platform_data),
358 				     GFP_KERNEL);
359 		if (pdata == NULL)
360 			return -ENOMEM;
361 		/* use default data in case of no platform data */
362 		pdata->flash_timeout = LM3646_FLASH_TOUT_MAX;
363 		pdata->led1_torch_brt = LM3646_LED1_TORCH_BRT_MAX;
364 		pdata->led1_flash_brt = LM3646_LED1_FLASH_BRT_MAX;
365 	}
366 	flash->pdata = pdata;
367 	flash->dev = &client->dev;
368 
369 	rval = lm3646_subdev_init(flash);
370 	if (rval < 0)
371 		return rval;
372 
373 	rval = lm3646_init_device(flash);
374 	if (rval < 0)
375 		return rval;
376 
377 	i2c_set_clientdata(client, flash);
378 
379 	return 0;
380 }
381 
382 static int lm3646_remove(struct i2c_client *client)
383 {
384 	struct lm3646_flash *flash = i2c_get_clientdata(client);
385 
386 	v4l2_device_unregister_subdev(&flash->subdev_led);
387 	v4l2_ctrl_handler_free(&flash->ctrls_led);
388 	media_entity_cleanup(&flash->subdev_led.entity);
389 
390 	return 0;
391 }
392 
393 static const struct i2c_device_id lm3646_id_table[] = {
394 	{LM3646_NAME, 0},
395 	{}
396 };
397 
398 MODULE_DEVICE_TABLE(i2c, lm3646_id_table);
399 
400 static struct i2c_driver lm3646_i2c_driver = {
401 	.driver = {
402 		   .name = LM3646_NAME,
403 		   },
404 	.probe = lm3646_probe,
405 	.remove = lm3646_remove,
406 	.id_table = lm3646_id_table,
407 };
408 
409 module_i2c_driver(lm3646_i2c_driver);
410 
411 MODULE_AUTHOR("Daniel Jeong <gshark.jeong@gmail.com>");
412 MODULE_AUTHOR("Ldd Mlp <ldd-mlp@list.ti.com>");
413 MODULE_DESCRIPTION("Texas Instruments LM3646 Dual Flash LED driver");
414 MODULE_LICENSE("GPL");
415