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8#include <linux/acpi.h>
9#include <linux/module.h>
10#include <linux/slab.h>
11#include <linux/i2c.h>
12#include <linux/backlight.h>
13#include <linux/delay.h>
14#include <linux/err.h>
15#include <linux/of.h>
16#include <linux/platform_data/lp855x.h>
17#include <linux/pwm.h>
18#include <linux/regulator/consumer.h>
19
20
21#define LP855X_BRIGHTNESS_CTRL 0x00
22#define LP855X_DEVICE_CTRL 0x01
23#define LP855X_EEPROM_START 0xA0
24#define LP855X_EEPROM_END 0xA7
25#define LP8556_EPROM_START 0xA0
26#define LP8556_EPROM_END 0xAF
27
28
29#define LP8557_BL_CMD 0x00
30#define LP8557_BL_MASK 0x01
31#define LP8557_BL_ON 0x01
32#define LP8557_BL_OFF 0x00
33#define LP8557_BRIGHTNESS_CTRL 0x04
34#define LP8557_CONFIG 0x10
35#define LP8555_EPROM_START 0x10
36#define LP8555_EPROM_END 0x7A
37#define LP8557_EPROM_START 0x10
38#define LP8557_EPROM_END 0x1E
39
40#define DEFAULT_BL_NAME "lcd-backlight"
41#define MAX_BRIGHTNESS 255
42
43enum lp855x_brightness_ctrl_mode {
44 PWM_BASED = 1,
45 REGISTER_BASED,
46};
47
48struct lp855x;
49
50
51
52
53
54
55
56
57struct lp855x_device_config {
58 int (*pre_init_device)(struct lp855x *);
59 u8 reg_brightness;
60 u8 reg_devicectrl;
61 int (*post_init_device)(struct lp855x *);
62};
63
64struct lp855x {
65 const char *chipname;
66 enum lp855x_chip_id chip_id;
67 enum lp855x_brightness_ctrl_mode mode;
68 struct lp855x_device_config *cfg;
69 struct i2c_client *client;
70 struct backlight_device *bl;
71 struct device *dev;
72 struct lp855x_platform_data *pdata;
73 struct pwm_device *pwm;
74 struct regulator *supply;
75 struct regulator *enable;
76};
77
78static int lp855x_write_byte(struct lp855x *lp, u8 reg, u8 data)
79{
80 return i2c_smbus_write_byte_data(lp->client, reg, data);
81}
82
83static int lp855x_update_bit(struct lp855x *lp, u8 reg, u8 mask, u8 data)
84{
85 int ret;
86 u8 tmp;
87
88 ret = i2c_smbus_read_byte_data(lp->client, reg);
89 if (ret < 0) {
90 dev_err(lp->dev, "failed to read 0x%.2x\n", reg);
91 return ret;
92 }
93
94 tmp = (u8)ret;
95 tmp &= ~mask;
96 tmp |= data & mask;
97
98 return lp855x_write_byte(lp, reg, tmp);
99}
100
101static bool lp855x_is_valid_rom_area(struct lp855x *lp, u8 addr)
102{
103 u8 start, end;
104
105 switch (lp->chip_id) {
106 case LP8550:
107 case LP8551:
108 case LP8552:
109 case LP8553:
110 start = LP855X_EEPROM_START;
111 end = LP855X_EEPROM_END;
112 break;
113 case LP8556:
114 start = LP8556_EPROM_START;
115 end = LP8556_EPROM_END;
116 break;
117 case LP8555:
118 start = LP8555_EPROM_START;
119 end = LP8555_EPROM_END;
120 break;
121 case LP8557:
122 start = LP8557_EPROM_START;
123 end = LP8557_EPROM_END;
124 break;
125 default:
126 return false;
127 }
128
129 return addr >= start && addr <= end;
130}
131
132static int lp8557_bl_off(struct lp855x *lp)
133{
134
135 return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
136 LP8557_BL_OFF);
137}
138
139static int lp8557_bl_on(struct lp855x *lp)
140{
141
142 return lp855x_update_bit(lp, LP8557_BL_CMD, LP8557_BL_MASK,
143 LP8557_BL_ON);
144}
145
146static struct lp855x_device_config lp855x_dev_cfg = {
147 .reg_brightness = LP855X_BRIGHTNESS_CTRL,
148 .reg_devicectrl = LP855X_DEVICE_CTRL,
149};
150
151static struct lp855x_device_config lp8557_dev_cfg = {
152 .reg_brightness = LP8557_BRIGHTNESS_CTRL,
153 .reg_devicectrl = LP8557_CONFIG,
154 .pre_init_device = lp8557_bl_off,
155 .post_init_device = lp8557_bl_on,
156};
157
158
159
160
161
162
163
164
165
166
167
168static int lp855x_configure(struct lp855x *lp)
169{
170 u8 val, addr;
171 int i, ret;
172 struct lp855x_platform_data *pd = lp->pdata;
173
174 if (lp->cfg->pre_init_device) {
175 ret = lp->cfg->pre_init_device(lp);
176 if (ret) {
177 dev_err(lp->dev, "pre init device err: %d\n", ret);
178 goto err;
179 }
180 }
181
182 val = pd->initial_brightness;
183 ret = lp855x_write_byte(lp, lp->cfg->reg_brightness, val);
184 if (ret)
185 goto err;
186
187 val = pd->device_control;
188 ret = lp855x_write_byte(lp, lp->cfg->reg_devicectrl, val);
189 if (ret)
190 goto err;
191
192 if (pd->size_program > 0) {
193 for (i = 0; i < pd->size_program; i++) {
194 addr = pd->rom_data[i].addr;
195 val = pd->rom_data[i].val;
196 if (!lp855x_is_valid_rom_area(lp, addr))
197 continue;
198
199 ret = lp855x_write_byte(lp, addr, val);
200 if (ret)
201 goto err;
202 }
203 }
204
205 if (lp->cfg->post_init_device) {
206 ret = lp->cfg->post_init_device(lp);
207 if (ret) {
208 dev_err(lp->dev, "post init device err: %d\n", ret);
209 goto err;
210 }
211 }
212
213 return 0;
214
215err:
216 return ret;
217}
218
219static void lp855x_pwm_ctrl(struct lp855x *lp, int br, int max_br)
220{
221 unsigned int period = lp->pdata->period_ns;
222 unsigned int duty = br * period / max_br;
223 struct pwm_device *pwm;
224
225
226 if (!lp->pwm) {
227 pwm = devm_pwm_get(lp->dev, lp->chipname);
228 if (IS_ERR(pwm))
229 return;
230
231 lp->pwm = pwm;
232
233
234
235
236
237 pwm_apply_args(pwm);
238 }
239
240 pwm_config(lp->pwm, duty, period);
241 if (duty)
242 pwm_enable(lp->pwm);
243 else
244 pwm_disable(lp->pwm);
245}
246
247static int lp855x_bl_update_status(struct backlight_device *bl)
248{
249 struct lp855x *lp = bl_get_data(bl);
250 int brightness = bl->props.brightness;
251
252 if (bl->props.state & (BL_CORE_SUSPENDED | BL_CORE_FBBLANK))
253 brightness = 0;
254
255 if (lp->mode == PWM_BASED)
256 lp855x_pwm_ctrl(lp, brightness, bl->props.max_brightness);
257 else if (lp->mode == REGISTER_BASED)
258 lp855x_write_byte(lp, lp->cfg->reg_brightness, (u8)brightness);
259
260 return 0;
261}
262
263static const struct backlight_ops lp855x_bl_ops = {
264 .options = BL_CORE_SUSPENDRESUME,
265 .update_status = lp855x_bl_update_status,
266};
267
268static int lp855x_backlight_register(struct lp855x *lp)
269{
270 struct backlight_device *bl;
271 struct backlight_properties props;
272 struct lp855x_platform_data *pdata = lp->pdata;
273 const char *name = pdata->name ? : DEFAULT_BL_NAME;
274
275 memset(&props, 0, sizeof(props));
276 props.type = BACKLIGHT_PLATFORM;
277 props.max_brightness = MAX_BRIGHTNESS;
278
279 if (pdata->initial_brightness > props.max_brightness)
280 pdata->initial_brightness = props.max_brightness;
281
282 props.brightness = pdata->initial_brightness;
283
284 bl = devm_backlight_device_register(lp->dev, name, lp->dev, lp,
285 &lp855x_bl_ops, &props);
286 if (IS_ERR(bl))
287 return PTR_ERR(bl);
288
289 lp->bl = bl;
290
291 return 0;
292}
293
294static ssize_t lp855x_get_chip_id(struct device *dev,
295 struct device_attribute *attr, char *buf)
296{
297 struct lp855x *lp = dev_get_drvdata(dev);
298
299 return scnprintf(buf, PAGE_SIZE, "%s\n", lp->chipname);
300}
301
302static ssize_t lp855x_get_bl_ctl_mode(struct device *dev,
303 struct device_attribute *attr, char *buf)
304{
305 struct lp855x *lp = dev_get_drvdata(dev);
306 char *strmode = NULL;
307
308 if (lp->mode == PWM_BASED)
309 strmode = "pwm based";
310 else if (lp->mode == REGISTER_BASED)
311 strmode = "register based";
312
313 return scnprintf(buf, PAGE_SIZE, "%s\n", strmode);
314}
315
316static DEVICE_ATTR(chip_id, S_IRUGO, lp855x_get_chip_id, NULL);
317static DEVICE_ATTR(bl_ctl_mode, S_IRUGO, lp855x_get_bl_ctl_mode, NULL);
318
319static struct attribute *lp855x_attributes[] = {
320 &dev_attr_chip_id.attr,
321 &dev_attr_bl_ctl_mode.attr,
322 NULL,
323};
324
325static const struct attribute_group lp855x_attr_group = {
326 .attrs = lp855x_attributes,
327};
328
329#ifdef CONFIG_OF
330static int lp855x_parse_dt(struct lp855x *lp)
331{
332 struct device *dev = lp->dev;
333 struct device_node *node = dev->of_node;
334 struct lp855x_platform_data *pdata = lp->pdata;
335 int rom_length;
336
337 if (!node) {
338 dev_err(dev, "no platform data\n");
339 return -EINVAL;
340 }
341
342 of_property_read_string(node, "bl-name", &pdata->name);
343 of_property_read_u8(node, "dev-ctrl", &pdata->device_control);
344 of_property_read_u8(node, "init-brt", &pdata->initial_brightness);
345 of_property_read_u32(node, "pwm-period", &pdata->period_ns);
346
347
348 rom_length = of_get_child_count(node);
349 if (rom_length > 0) {
350 struct lp855x_rom_data *rom;
351 struct device_node *child;
352 int i = 0;
353
354 rom = devm_kcalloc(dev, rom_length, sizeof(*rom), GFP_KERNEL);
355 if (!rom)
356 return -ENOMEM;
357
358 for_each_child_of_node(node, child) {
359 of_property_read_u8(child, "rom-addr", &rom[i].addr);
360 of_property_read_u8(child, "rom-val", &rom[i].val);
361 i++;
362 }
363
364 pdata->size_program = rom_length;
365 pdata->rom_data = &rom[0];
366 }
367
368 return 0;
369}
370#else
371static int lp855x_parse_dt(struct lp855x *lp)
372{
373 return -EINVAL;
374}
375#endif
376
377static int lp855x_parse_acpi(struct lp855x *lp)
378{
379 int ret;
380
381
382
383
384
385
386 ret = i2c_smbus_read_byte_data(lp->client, lp->cfg->reg_brightness);
387 if (ret < 0)
388 return ret;
389
390 lp->pdata->initial_brightness = ret;
391
392 ret = i2c_smbus_read_byte_data(lp->client, lp->cfg->reg_devicectrl);
393 if (ret < 0)
394 return ret;
395
396 lp->pdata->device_control = ret;
397 return 0;
398}
399
400static int lp855x_probe(struct i2c_client *cl, const struct i2c_device_id *id)
401{
402 const struct acpi_device_id *acpi_id = NULL;
403 struct device *dev = &cl->dev;
404 struct lp855x *lp;
405 int ret;
406
407 if (!i2c_check_functionality(cl->adapter, I2C_FUNC_SMBUS_I2C_BLOCK))
408 return -EIO;
409
410 lp = devm_kzalloc(dev, sizeof(struct lp855x), GFP_KERNEL);
411 if (!lp)
412 return -ENOMEM;
413
414 lp->client = cl;
415 lp->dev = dev;
416 lp->pdata = dev_get_platdata(dev);
417
418 if (id) {
419 lp->chipname = id->name;
420 lp->chip_id = id->driver_data;
421 } else {
422 acpi_id = acpi_match_device(dev->driver->acpi_match_table, dev);
423 if (!acpi_id)
424 return -ENODEV;
425
426 lp->chipname = acpi_id->id;
427 lp->chip_id = acpi_id->driver_data;
428 }
429
430 switch (lp->chip_id) {
431 case LP8550:
432 case LP8551:
433 case LP8552:
434 case LP8553:
435 case LP8556:
436 lp->cfg = &lp855x_dev_cfg;
437 break;
438 case LP8555:
439 case LP8557:
440 lp->cfg = &lp8557_dev_cfg;
441 break;
442 default:
443 return -EINVAL;
444 }
445
446 if (!lp->pdata) {
447 lp->pdata = devm_kzalloc(dev, sizeof(*lp->pdata), GFP_KERNEL);
448 if (!lp->pdata)
449 return -ENOMEM;
450
451 if (id) {
452 ret = lp855x_parse_dt(lp);
453 if (ret < 0)
454 return ret;
455 } else {
456 ret = lp855x_parse_acpi(lp);
457 if (ret < 0)
458 return ret;
459 }
460 }
461
462 if (lp->pdata->period_ns > 0)
463 lp->mode = PWM_BASED;
464 else
465 lp->mode = REGISTER_BASED;
466
467 lp->supply = devm_regulator_get(dev, "power");
468 if (IS_ERR(lp->supply)) {
469 if (PTR_ERR(lp->supply) == -EPROBE_DEFER)
470 return -EPROBE_DEFER;
471 lp->supply = NULL;
472 }
473
474 lp->enable = devm_regulator_get_optional(dev, "enable");
475 if (IS_ERR(lp->enable)) {
476 ret = PTR_ERR(lp->enable);
477 if (ret == -ENODEV) {
478 lp->enable = NULL;
479 } else {
480 return dev_err_probe(dev, ret, "getting enable regulator\n");
481 }
482 }
483
484 if (lp->supply) {
485 ret = regulator_enable(lp->supply);
486 if (ret < 0) {
487 dev_err(dev, "failed to enable supply: %d\n", ret);
488 return ret;
489 }
490 }
491
492 if (lp->enable) {
493 ret = regulator_enable(lp->enable);
494 if (ret < 0) {
495 dev_err(dev, "failed to enable vddio: %d\n", ret);
496 goto disable_supply;
497 }
498
499
500
501
502
503 usleep_range(1000, 2000);
504 }
505
506 i2c_set_clientdata(cl, lp);
507
508 ret = lp855x_configure(lp);
509 if (ret) {
510 dev_err(dev, "device config err: %d", ret);
511 goto disable_vddio;
512 }
513
514 ret = lp855x_backlight_register(lp);
515 if (ret) {
516 dev_err(dev, "failed to register backlight. err: %d\n", ret);
517 goto disable_vddio;
518 }
519
520 ret = sysfs_create_group(&dev->kobj, &lp855x_attr_group);
521 if (ret) {
522 dev_err(dev, "failed to register sysfs. err: %d\n", ret);
523 goto disable_vddio;
524 }
525
526 backlight_update_status(lp->bl);
527
528 return 0;
529
530disable_vddio:
531 if (lp->enable)
532 regulator_disable(lp->enable);
533disable_supply:
534 if (lp->supply)
535 regulator_disable(lp->supply);
536
537 return ret;
538}
539
540static int lp855x_remove(struct i2c_client *cl)
541{
542 struct lp855x *lp = i2c_get_clientdata(cl);
543
544 lp->bl->props.brightness = 0;
545 backlight_update_status(lp->bl);
546 if (lp->enable)
547 regulator_disable(lp->enable);
548 if (lp->supply)
549 regulator_disable(lp->supply);
550 sysfs_remove_group(&lp->dev->kobj, &lp855x_attr_group);
551
552 return 0;
553}
554
555static const struct of_device_id lp855x_dt_ids[] = {
556 { .compatible = "ti,lp8550", },
557 { .compatible = "ti,lp8551", },
558 { .compatible = "ti,lp8552", },
559 { .compatible = "ti,lp8553", },
560 { .compatible = "ti,lp8555", },
561 { .compatible = "ti,lp8556", },
562 { .compatible = "ti,lp8557", },
563 { }
564};
565MODULE_DEVICE_TABLE(of, lp855x_dt_ids);
566
567static const struct i2c_device_id lp855x_ids[] = {
568 {"lp8550", LP8550},
569 {"lp8551", LP8551},
570 {"lp8552", LP8552},
571 {"lp8553", LP8553},
572 {"lp8555", LP8555},
573 {"lp8556", LP8556},
574 {"lp8557", LP8557},
575 { }
576};
577MODULE_DEVICE_TABLE(i2c, lp855x_ids);
578
579#ifdef CONFIG_ACPI
580static const struct acpi_device_id lp855x_acpi_match[] = {
581
582 { "XMCC0001", LP8556 },
583 { }
584};
585MODULE_DEVICE_TABLE(acpi, lp855x_acpi_match);
586#endif
587
588static struct i2c_driver lp855x_driver = {
589 .driver = {
590 .name = "lp855x",
591 .of_match_table = of_match_ptr(lp855x_dt_ids),
592 .acpi_match_table = ACPI_PTR(lp855x_acpi_match),
593 },
594 .probe = lp855x_probe,
595 .remove = lp855x_remove,
596 .id_table = lp855x_ids,
597};
598
599module_i2c_driver(lp855x_driver);
600
601MODULE_DESCRIPTION("Texas Instruments LP855x Backlight driver");
602MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
603MODULE_LICENSE("GPL");
604
